Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were ra...Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.展开更多
It is well established in experimental animals and Humans that endothelial cells,which cover the luminal surface of all blood vessels,have a pivotal role in the control of vascular homeostasis.The protective effect of...It is well established in experimental animals and Humans that endothelial cells,which cover the luminal surface of all blood vessels,have a pivotal role in the control of vascular homeostasis.The protective effect of endothelial cells is mostly due to their ability to respond to circulating hormones,autacoids,blood-and platelet-derived factors,and also to blood flow by inducing potent vasoprotectivemechanismsincluding predominantlythe formation of nitric oxide(NO),and,often also to some extent,endothelium-derived hyperpolarization,and prostacyclin(PGI2).Besides being a potent vasodilator,NO also effectively prevents platelet activation and has anti-thrombotic and anti-atherosclerotic properties.An endothelial dysfunction characterized by a reduced generation of these endothelium-dependent vasodilator mechanisms associated with vascular oxidative stress and the formation of endothelium-derived contracting factors such as contractile prostanoids is often observed in most types of cardiovascular diseases including hypertension,hypercho⁃lesterolemia,diabetes,and also during physiological ageing in both experimental animals and Humans.Nutrition-derived polyphenols such as those from grapes,tea,cocoa,and berries have been shown to stimulate the endothelial formation of NO by activating the Src/PI3-kinase/Akt-dependent phosphorylation of endothelial NO synthase(eNOS)and to enhance eNOS expression.As a consequence,the active polyphenols will promote a sustained forma⁃tion of NO that contributes to protect the vascular system.Polyphenol-rich products have also been shown to improve an established endothelial dysfunction and to delay the onset of the induction of an endothelial dysfunction in several experimental models of cardiovascular diseases including hypertension and in ageing.Moreover,endothelial senescence characterized by cell cycle arrest and the acquisition of a pro-inflammatory and pro-atherothrombotic phenotype has been identified as an early event promotingthe development of endothelial dysfunc⁃tion.Premature endothelial senescence appears to affect,in particular,arterial sites at risk such as curvatures and bifur⁃cations that are characterized by disturbed flow and low shear stress.The pro-senescent process can be further increased in the presence of a high concentration of glucose,oxidized LDL,and angiotensinⅡ.Anthocyanin-rich products have been shown to accumulate preferentially in senescent endothelial cells,to reduce the expression of cell cycle regulators such as p16,p21 and p53,and to improve the endothelial function.The protective effect is mostly due to their ability to reduce vascular oxidative stress by inhibiting the overexpression of NADPH oxidase and the local angiotensin system.Thus,nutrition-derived polyphenols may be an interesting approach to delay the onset of risk factor-and ageing-related endothelial senescence and dysfunction and,hence,to promote vascular health.展开更多
OBJECTIVE To explore the role of gecko crude peptides(GCPs)in the proliferation,apoptosis,migration and lymphangiogenesis of human hepatocellular carcinoma cells(Hep G2)and human lymphaticendothelial cells(HLECs)in vi...OBJECTIVE To explore the role of gecko crude peptides(GCPs)in the proliferation,apoptosis,migration and lymphangiogenesis of human hepatocellular carcinoma cells(Hep G2)and human lymphaticendothelial cells(HLECs)in vitro.METHODS The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay was used to evaluate the anti-proliferative effect of GCPs and si RNA-VEGF-C on Hep G2 cells,Hoechst 33258 staining and flow cytometry were performed to analyze cycle and apoptosis.The migration and invasion ability of cells were assayed by transwell chamber experiment and wound-healing assay.The protein and m RNA expressions of vascular endothelial growth factor-C(VEGF-C)and CXC chemokine receptor-4(CXCR4)were detected by q-PCR,immunofluorescence,Western blot.The protein expressions of the extracellular signal regulated kinase(ERKI/2),c-Jun N-terminal kinase(JNK),p38-mitogen activated protein kinases(p38 MAPK),serine/threonine kinase(Akt)and phosphatidylinositol-3-kinase(PI3K)were detected by western blot.The anti-lymphangiogenesis effect of GCPs on the HLECs was analyzed using an in vitro tube-formation assay.The protein and m RNA expressions of vascular endothelial growth factor receptor-3(VEGFR-3)and stromal cell-derived factor-1(SDF-1)were detected by q-PCR,Western blot.RESULTS GCPs and si RNA-VEGF-C inhibited Hep G2 proliferation,invasion and migration,and the most obvious inhibitory effect was both synergistic effects.Thus,GCPs suppressed HLECs proliferation,migration and tubelike structure formationin a dose-dependent manner,and had inhibitory effect of tumor-induced lymphangiogenesis in vitro.Additionally,we found that GCPs and si RNA-VEGF-C decreased the expressions of MMP-2,MMP-9,VEGF-C,CXCR4,phospho-ERK1/2,phospho-P38,phospho-JNK and PI3K in Hep G2 cells.Moreover,GCPs had a dose-dependent depressive effecton the expressions of VEGFR-3,SDF-1 in HLECs.CONCLUSION The low expression of VEGF-C mediated by si RNA-VEGF-C and GCPs inhibit tumor proliferation,invasion and migrationby suppressing the MAPK signaling pathway through reduced levels of VEGF-C,and GCPs inhibit tumor lymphangiogenesis by suppressing the CXCR4/SDF-1 signaling pathway through suppressed VEGF-C/VEGFR-3.展开更多
Aim Salidroside （SAL） is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density li...Aim Salidroside （SAL） is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density lipoprotein receptor - deficient mice. This study was to investigate the molecular mechanism of antiatherogenic effects of SAL. Method Six-week old apoE-/- male mice were fed a high-fat diet for 8 weeks and then were ad- ministered with SAL for another 8 weeks. Atherosclerotic lesion and vascular function were analyzed. Primary cul- tured human umbilical vein endothelial cells （HUVECs） were prepared. Superoxide anion （O2^-）, NO produc- tion, mitochondrial membrane potential （△ψm） and intracellular ATP and AMP levels were measured. Expression of eNOS and AMPK were analyzed by Western blot. Result SAL significantly improved endothelial function asso- ciated with increasing eNOS activation thus reduced the atherosclerotic lesion area. SAL increased eNOS-Serl177 phosphorylation and decreased eNOS-Thr495 phosphorylation. SAL significantly activated AMP-activated protein ki- nase （AMPK）. Both AMPK inhibitor and AMPK small interfering RNA （siRNA） abolished SAL-induced Akt- Ser473 and eNOS-Serl177 phosphorylation. In contrast, LY294002, the PI3k/Akt pathway inhibitor, abolished SAL-induced phosphorylation and expression of eNOS. SAL decreased cellular ATP content and increased the cel- lular AMP/ATP ratio, which was associated with the activation of AMPK. SAL was found to decrease A^m, which is likely consequence of reduced ATP production. Conclusion The action of SAL to reduce atherosclerotic lesion formation may at least be attributed to its effect on improving endothelial function by promoting nitric oxide （NO） production, which was associated with mitochondria depolarization and subsequent activation of the AMPK/PI3 IC/ Akt/eNOS pathway. Taken together, our data described the effects of SAL on mitochondria, which played critical roles in improving endothelial function in atherosclerosis.展开更多
Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of ather...Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of atherosclerosis by increasing endothelial adhesiveness.Here,we sought to investigate whether CTRP1 also influences vascular dilatory functions.展开更多
Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional ...Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional basis of cells motility,and therefore,from a biomechanical point of view,the purpose of this study is to investigate the effects of FB1 on the biomechanical properties,migration capacity and cytoskeletal structure of human umbilical vein endothelial cells(HUVECs),which may lay an experimental foundation for further exploration of the toxicity mechanism of fumonisin.Methods HUVECs were cultured and treated with different concentrations of FB1.Then,CCK-8 kit was used to detect the effect of FB1 on the survival rate.The osmotic fragility of the cells was measured after treatment with different osmotic pressures for30 min.The cell membrane fluidity was measured by fluorescence polarization method.The cell electrophoretic mobility was measured by cell electrophoretic apparatus.The migration capacity of the cells was observed by scratch repair assay.The changes of reactive oxygen species and cytoskeletal structure were observed by confocal laser scanning microscopy.Finally,the mRNA and protein relative expression levels of cytoskeletal binding proteins were detected by real-time PCR,Western blotting and confocal laser scanning.Results The results of CCK-8 showed that FB1 could significantly inhibit the proliferation of HUVECs in a dose-and time-dependent manner.After treatment of HUVECs with FB1,the hypotonic resistance of the cell,cell surface charge,cell membrane fluidity and migration capacity were all weakened,while reactive oxygen species were significantly increased and the cytoskeletal structure was significantly reorganized.Furthermore,RTPCR results showed that the mRNA relative expression levels of cytoskeletal binding proteins,exception of actin,were down-regulated after treated with FB1.Besides,Western blotting and statistical analysis based on fluorescence intensity of laser confocal microscopy confirmed theses changes in protein level.Conclusions FB1 can significantly affect the biomechanical properties and motility of HUVECs,which may be directly correlated to the remodel of F-actin cytoskeleton,as well as the relative expression changes of cytoskeletal binding proteins.It is significant for further exploring the toxicity mechanism of fumonisin.展开更多
Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the hom...Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system.In addition to forming a transport barrier between the blood and vessel wall,vascular ECs play important roles in regulating circulation functions.Besides biochemical stimuli,blood flow induced(hemodynamic)mechanical stimuli,such as shear stress,pressure and circumferential stretch,modulate EC morphology and functions by activating mechanosensors,signaling pathways,and gene and protein expressions.The EC responses to the hemodynamic forces(mechano-sensing and transduction)are critical to maintaining normal vascular functions.Failure in the mechano-sensing and transduction leads to serious vascular diseases including hypertension,atherosclerosis,aneurysms and thrombosis,to name a few[1].On the luminal surface of our blood vessels,there is a thin layer called endothelial surface glycocalyx(ESG)which consists of proteoglycans,glycosaminoglycans(GAGs)and glycoproteins.The GAGs in the ESG are heparan sulfate(HS),hyaluronic acid(HA),chondroitin sulfate(CS),and sialic acid(SA)[2].In order to play important roles in vascular functions,such as being a mechanosensor and transducer for the endothelial cells(ECs)to sense the blood flow,a molecular sieve to maintain normal microvessel permeability and a barrier between the circulating cells and endothelial cells forming the vessel wall,the ESG should have an organized structure at the molecular level.Due to the limitations of optical and electron microscopy,the ultra-structure and organization of ESG has not been revealed until recent development of a super high resolution fluorescence optical microscope,STORM(Stochastic Optical Reconstruction Microscopy).The diffraction of a single fluorescence molecule can be described as the point spread function(PSF).When the light of wavelengthλexcites the fluorophore(emitter),the intensity profile of the spot is defined as the PSF with the width^0.6λ/NA,NA is the numerical aperture of the objective.The diffraction-limited image resolution,for a high numerical aperture objective lens,is^200 nm in the lateral direction and^500 nm in the axial direction,for a conventional fluorescence microscope.The key idea of the single-molecule localization microscopy is to light the molecule,in turn,to achieve the nanometer-level accuracy of their position and reconstruction into a super-resolution image,such as STORM.STORM employs photo-switching mechanisms to stochastically activate individual molecules(photo-switchable or photoactivatable fluorophores)within the diffraction-limited region at different times.Then images with sub-diffraction limit resolution are reconstructed from the measured positions of individual fluorophores[3].To trade the super spatial resolution(accuracy),STORM sacrifices its temporal resolution(efficiency)by switching the state and sequentially exciting the emitters at a high density.Rust et al[3]employed organic dyes and fluorescent proteins as photo-switchable emitters to trade temporal resolution for a super spatial resolution(~20 nm lateral and^50 nm axial at present,can go down to a couple of nanometers if using smaller peptides or antibody fragments instead of currently used whole anti-bodies),which is an order of magnitude higher than conventional confocal microscopy.In the current study,we employed STORM to reveal the major ultra-structural components of the ESG,HS and HA,and their organization at the surface of the cultured EC monolayer[4].Materials and methods We used newly acquired Nikon-STORM system to observe the ESG on in vitro EC(bEnd3,mouse brain microvascular endothelial cells)monolayers.After confluency,the bEnd3 cells were immunolabeled with anti-HS,fol-lowed by an ATT0488 conjugated goat anti-mouse IgG,and with biotinylated HA binding protein,followed by an AF647 conjugated anti-biotin.The ESG was then imaged by the STORM with a 100x/1.49 oil immersed lens.Multiple Reporters of ATT0488 and AF647 with alternating illumination were used to acquire the 3D images of HS and HA.The field of 256×256(40×40μm2)of HS and HA at the surface of ECs was obtained based on totally 40,000 of EM-CCD captured images for each reporter at a capturing speed of 19 ms/frame.Results HA is a long molecule weaving into a network which covers the endothelial luminal surface.The diameter of the HA segments is 185.3±44.7 nm,155.5±57.2 nm,and 156.9±56.1 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.In contrast,HS is a shorter molecule,perpendicular to the cell surface.HA and HS are partially overlapped with each other at the endothelial luminal surface.We quantified the length,diameter,orientation,and density of HS at the top,middle and bottom regions of the endothelial surface.The diameter of the observed HS is 191.0±46.0 nm,284.3±71.1 nm,and 184.2±59.6 nm,and the length of the HS is 621.0±75.7 nm,651.0±118.0 nm,and 575.2±105.6 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.For the HS orientation,its angle with the cell surface is 92.9±1.9,88.7±8.2,and 96.2±10.9 degree,respectively,at the top,middle and bottom regions.The angle of 90 degree is perfectly perpendicular to the cell surface.For the HS distribution,the average density is0.398 elements/μm2,0.345 elements/μm2 and 0.665 elements/μm2,respectively,and the distance between the adjacent HS is 1 694.4±628.1 nm,1 844.8±758.5 nm,and 1 221.9±450.7 nm,respectively,at the top,middle and bottom regions.Conclusions Our results suggest that HS plays a major role in mechanosensing and HA plays a major role in the molecular sieve,due to their organization,ultra-structure and distribution.展开更多
Human endothelial cells derived from umbilical vein could besubcultured and survive 25 passage (double time 20～25 hours, 60～75 cumula-tive population doublings). An observation was performed with light mi-croscopy, ...Human endothelial cells derived from umbilical vein could besubcultured and survive 25 passage (double time 20～25 hours, 60～75 cumula-tive population doublings). An observation was performed with light mi-croscopy, electron microscopy and immunofluorescence microscopy using specificantiserum against factor Ⅷrelated antigen. It identified that the cultured cellswere endothelial cells. Medium RPMI-1640 supplemented with 20% humanserum, endothelial cell growth factor 200μg/ml, heparin 100μg/ml and gelatincoated flasks were very important conditions for long-term culture of humanendothelial cell.展开更多
The technology of induced pluripotent stem cell(iPSCs)has enabled the conversion of somatic cells into primitive undifferentiated cells via reprogramming.This approach provides possibilities for cell replacement thera...The technology of induced pluripotent stem cell(iPSCs)has enabled the conversion of somatic cells into primitive undifferentiated cells via reprogramming.This approach provides possibilities for cell replacement therapies and drug screening,but the potential risk of tumorigenesis hampers further development and application.How to generate required differentia-ted cells without initiating tumor progression remains a huge challenge.Here we show that mouse embryonic fibroblasts could be differentiated into valvular endothelial cell(VEC)like cells.VECs are critical in valve replacements in aortic valve failure.VEC-associated gene and protein expression and functional assays were quantified for these VEC-like cells.We show that mouse embryonic fibroblasts could be converted into VEC-like cells.Our results suggest that it is possible to convert mouse embryonic fibroblasts into VEC-like cells without first reprogramming them into pluripotent stem cells,minimizing the possibility of tumorigenesis.展开更多
OBJECTIVE Highly electronegative L5 low-density lipoprotein(LDL),an atherogenic LDL,induces endothelial cell(EC)senescence and has been implicated in the progression of atherosclerosis.We examine whether sesamol,a nat...OBJECTIVE Highly electronegative L5 low-density lipoprotein(LDL),an atherogenic LDL,induces endothelial cell(EC)senescence and has been implicated in the progression of atherosclerosis.We examine whether sesamol,a natural organic compound and component of sesame oil,prevents EC senescence induced by electronegative LDL(L5)and to investigate the underlying mechanisms.METHODS Syrian hamsters,which have a LDL profile similar to that of humans,were fed a normal chow diet(control),a high-fat diet(HFD),or a HFD supplemented with the administration of 50 or 100mg·kg-1 sesamol via oral gavage(HFD+sesamol)for 16 weeks(n=10 per group).Among these groups,we compared plasma L5 levels and aortic endothelial senescence in the aortic arch.In vitro,we examined the effects of sesamol on human aortic endothelial cell(HAEC)senescence and signaling pathways induced by L5.RESULTS Hamsters in the HFD group had higher plasma L5 levels than did the HFD+sesamol groups or control group.Betagalactosidase(gal)staining showed that aortic endothelial senescence was markedly increased in the aortic arch of the HFD group but not in that of the HFD+sesamol groups when compared with the control group.In vitro,treatment of HAECs with sesamol(1-3mol·L-1)blocked L5-induced EC senescence in a dose-dependent manner.Sesamol also markedly inhibited the L5-induced phosphorylation of p38 MAPK and p53 activation and increased Mdm2 and phosphorylation of Akt.CONCLUSION The critical findings of this study suggest that sesamol may provide protection against atherosclerosis and the development of cardiovascular disease in humans.展开更多
Introduction Primary cilium is a non-motile microstructure,protruding from cell surface of most mammalian cells.It was previously thought to be vestigial.However,recent studies indicate that it may serve as one of the...Introduction Primary cilium is a non-motile microstructure,protruding from cell surface of most mammalian cells.It was previously thought to be vestigial.However,recent studies indicate that it may serve as one of the most vital mechanosensors for many types of cells such as epithelial and endothelial cells and osteocytes.Protruding from the apical membrane,the primary cilium can directly sense subtle variation of mechanical forces exerted on the cell and then transduce the mechanical cues into biochemical signals into the cell,although the mechanism remain elusive.Vascular endothelial cells(ECs)lining the inner wall of our blood vessels are continuously exposed to the blood flow.In order to maintain proper functions for the cardiovascular system,ECs should have a variety of mechano-sensors and transducers to sense the blood flow change and adjust the vessel size and transport across the vessel wall accordingly.Among more than a dozen recognized EC mechano-sensors,the primary cilium has drawn more and more attention recently.Primary cilium on endothelial cells is essential for the homeostasis of vessels.It is reported to be prevalent in areas of disturbed flow where atherosclerosis and intracranial aneurysm usually occur.Deficiencies of primary cilia may promote atherosclerosis,endothelial-to-mesenchymal transition(EndoMT)and loss of direction orientation,to name a few.Therefore understanding why the primary cilia are necessary to maintain the homeostasis of blood vessels and how will help us develop better treatment strategies for the common cardiovascular diseases.Dimension and structure of primary cilium Primary cilium is reported to be shorter than 8 in length and about 0.2 in diameter.The length of primary cilium varies in different cell types and under different conditions.The major structural components of the primary cilium include basal body,ciliary axoneme(consisting of nine doublet microtubules),ciliary membrane,transition zone,basal feet,and striated rootlets.Each part of the primary cilium is essential and has specific function.Current methods investigating the EC primary cilium as a mechano-sensor:Immunostaining and imaging techniques have been used to investigate the molecular mechanisms by which EC primary cilium serves as a mechano-sensor and transducer.It has been found that various proteins locate on the primary cilium,working together to maintain the function of primary cilium.Some proteins function as ion-channels,mediating Ca2+entry into the primary cilium.Some are involved in the cascade signal pathway.Others are related to the assembly and maintenance of primary cilium.Briefly,the flow induces the deflection of the EC primary cilium,which triggers calcium increase via opening of the PC2 cation channel that is responsible for calcium ion influx.This PC2 cation channel is localized to the primary cilium and is assumed to be stretch-activated.The resulting change in the intracellular calcium concentration then regulates numerous molecular activities inside the cell that contribute to vessel homeostasis.In addition to triggering calcium release,another mechanism has also been found in blood-pressure maintenance in the vasculature,where the vessel diameter is regulated by endothelial primary cilia through adjusting nitric oxide production.So far,little is known about the mechanical mechanism behind this deflection-triggered o-pening of signaling pathways.For example,what is the flow induced bending behavior and force distribution? What is the threshold value of stretch/defection for activating a corresponding signaling pathway? These all remain to be answered.In combination of image data and experiments,several computational models have been established to answer these questions.However,the current models are not able to include the complex structure of primary cilium and the model predictions are limited.Future studies With the development of super high resolution optical microscopy,more detailed images for the structural(molecular)components of EC primary cilia will be revealed,especially when the ECs are alive and the forces are known.Combining these experimental observations with more sophisticated mathematical models will elucidate the mechano-sensing mechanism of EC primary cilia,as the force and stress distribution on cilium along with other mechanical properties are still beyond the capability of experimental approaches due to the scales of the quantities involved.By using numerical approaches,much more detailed dynamic information can be obtained.展开更多
Aim Alpha7 nicotinic acetylcholine receptor （α7nAChR）, a subtype of nAChR regulating neurotrans- mission in central nervous system, is an essential regulator of cholinergic antiinflammatory pathway in periphery. Th...Aim Alpha7 nicotinic acetylcholine receptor （α7nAChR）, a subtype of nAChR regulating neurotrans- mission in central nervous system, is an essential regulator of cholinergic antiinflammatory pathway in periphery. The present study was to determine the effects of activation of α7nAChR on oxidant stress-induced injury in endo- thelial cells. Methods Cultured human umbilical vein endothelial cells were treated with H202 （400 μmol · L^-1） or H202plus PNU-282987 （ 10 μmol · L^-1 ）. Cell viability and membrane integrity were measured. AnnexinV ＋ PI assay, immunoblotting of bcl-2, bax and cleaved caspase-3, and immunofluorescence of apoptosis inducing factor （AIF） were performed to evaluate apoptosis. Protein expression of vascular peroxidase-1 （ VPO-1 ） and phosphor- JNK were measured by immunoblotting. Results Activation of α7nAChR by a selective agonist PNU-282987 pre-vented H202-indced decrease of cell viability and increase of lactate dehydrogenase release. Activation of α7nAChR markedly reduced cell apoptosis and intracellular oxidative stress level. Moreover, activation of α7nAChR reduced H2 02 -induced VPO-1 protein upregulation and JNK1/2 phosphorylation. The inhibitory effect of α7nAChR activa- tion on VPO-1 was blocked by JNK inhibitor SP600125. In addition, pretreatment of α7nAChR antagonist methyl- lycaconitine blocked the cytoprotective effect of PNU-282987. Conclusion These results provide the first evidence that activation of α7nAChR protects against oxidant stress-induced damage by suppressing VPO-1 in a JNK signa- ling pathway-dependent manner in endothelial cells.展开更多
Aim Magnesium lithospermate B （MLB） is the most abundant hydrophilic active component of Salvia rniltiorrhiza Radix, a traditional Chinese herbal medicine mainly used to treat cardiovascular diseases. Studies have s...Aim Magnesium lithospermate B （MLB） is the most abundant hydrophilic active component of Salvia rniltiorrhiza Radix, a traditional Chinese herbal medicine mainly used to treat cardiovascular diseases. Studies have shown that endothelial activation contributes to the pathophysiology of cardiovascular diseases such as atherosclero- sis, diabetic vasculopathy, heart failure and hypertension. In the present study, the effects of MLB on endothelial activation were investigated. Lipopolysaccharide （LPS） 1 mg L^-1 was employed to induce endothelial activation, which was determined by relative gene expression and endothelial adhesion assay. Results showed that pretreatment with MLB attenuated LPS-induced ICAM1, VCAM1 and TNF-α upregulation in human dermal microvascular endo- thelial cells （HMEC-1） in dose-dependent manner, which contributed to the reduction of THP-1 adhesion to HMEC-1. Furthermore, it was revealed that 100 μmol · L^-1 MLB significantly decreased the nuclear translocation of NF-KB p65, a critical transcription factor in LPS-indueed inflammatory response, through the inhibition of IKBμ degradation. Besides, the transcriptional activity of NF-KB p65 was also inhibited by the pretreatment of MLB. Mo- reover, MLB pretreatment considerably inhibited LPS-induced p38 phosphorylation, which at least partly contribu- ted to the reduction of ICAM1 expression. In conclusion, these findings suggest that MLB inhibits LPS-induced nu- clear translocation and transcripitional activity of NF-KB, thus attenuates the increased expression of adhesion mole- cules and inflammatory factors, protects endothelial cells from LPS-induced activation.展开更多
OBJECTIVE This study was aimed to evaluate the effect of mangosteen peel extract(MPE)on migration of human umbilical vein endothelial cells(HUVECs)treated with LPS.METHODS Cultured HUVECs were divided into five groups...OBJECTIVE This study was aimed to evaluate the effect of mangosteen peel extract(MPE)on migration of human umbilical vein endothelial cells(HUVECs)treated with LPS.METHODS Cultured HUVECs were divided into five groups:normal(untreated)group,positive control group treated with LPS at dose of 20ng·mL-1 for 24 h,and groups pre-treated with LPS at dose of 20ng·mL-1 for 24 h followed by incubation with MPE at doses of 1,2,and 4-1μg·mL,respectively.HUVECs migration was evaluated using wound-healing migration assay after 24 h of treatment.RESULTS LPS significantly(P<0.05)impaired HUVECs migration compared to the normal.MPE at dose of 1μg·mL-1 increased migration of LPS-treated HUVECs significantly(P<0.05)compared to the positive control and near to the normal level.CONCLUSION The mangosteen peel extract is able to dose-dependently preserve the endothelial cells function.展开更多
Aim Premature senescence of the vascular endothelial cells is a leading cause of endothelial dysfunc- tion. Our previous observations suggest that up-regulation of heme oxygenase-1 （HO-1） improves endothelial func- ...Aim Premature senescence of the vascular endothelial cells is a leading cause of endothelial dysfunc- tion. Our previous observations suggest that up-regulation of heme oxygenase-1 （HO-1） improves endothelial func- tion by attenuating endothelium-dependent contractions and potentiating endothelium-dependent hyperpolarization. The present study aimed to investigate the effect of HO-1 on endothelial senescence and the underlying mecha- nisms. Methods Human umbilical vein endothelial cells （HUVEC） were treated with 50 μmol · L^-1 H2 02 to in- duce premature senescence. HO-1 was up-regulated by the pharmacological inducer hemin, whereas it was knocked down by 1RNA silencing. Results H2 02 remarkably induced HUVEC senescence as detecting by the immunostain- ing of senescence-associated β-galactosidase. Overexpression of HO-1 by hemin reversed H2 02 -induced senescence in a dose-dependent manner. Silencing of HO-1 triggered HUVEC senescence, even in the absence of H202. In addition, HO-1 induction prevented the decrease of eNOS phosphorylation at Serine 1177 stimulated by H202. Contrarily, HO-1 silencing impaired eNOS phosphorylation. The total protein expression of eNOS was not altered by HO-1. Further, co-immunoprecipitation experiments showed that HO-1 directly interacted with eNOS. Conclusions HO-1 ameliorated endothelial senescence probably through interacting with eNOS and affecting its phosphoryla- tion modification.展开更多
OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TME...OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TMEM16A in the vascular endothelial dysfunction in hypertension is unclear.METHODS In the study,RT-PCR,Western blotting,co-immunopricipitation,confocal imaging,patch-clamp,and endothelial-specific TMEM16A transgenic and knockout mice were employed.RESULTS We found that TMEM16A was expressed abundantly and functioned as Ca CC in endothelial cells.AngiotensinⅡ(AngⅡ)induced endothelial dysfunction with an increase in TMEM16A expression,which was alleviated by TMEM16A inhibitor.Further studies revealed that TMEM16A endothelial-specific knockout significantly lowered the blood pressure and ameliorated endothelial dysfunction in AngⅡ-induced hypertension,whereas,TMEM16A endothelial-specific overexpression showed the opposite effects.These results were related to the increased reactive oxygen species(ROS)generation,NADPH oxidase activation,and Nox2,p22phox expression facilitated by TMEM16A upon AngⅡ-induced hypertensive challenges.Moreover,TMEM16A directly interacted with Nox2 monomer and reduced the degradation of Nox2 through the proteasome-dependent endoplasmic recticulum-associated degradation pathway.TMEM16A also potentiated the translocation of p47phox and p67phox from cytosol to cell membrane and the subsequent interaction with Nox2.CONCLUSION Our results demonstrated that TMEM16A,as Ca CC,is a positive regulator of ROS generation via upregulating the activation of Nox2 NADPH oxidase in the vascular endothelium,and therefore facilitates endothelial dysfunction and hypertension.Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated cardiovascular diseases.展开更多
OBJECTIVE The receptor-tyrosine kinase ErbB4 is present throughout the primate brain and has a distinct functional profile.In the present study,we investigate the potential role of endothelial ErbB4 receptor signaling...OBJECTIVE The receptor-tyrosine kinase ErbB4 is present throughout the primate brain and has a distinct functional profile.In the present study,we investigate the potential role of endothelial ErbB4 receptor signaling in the brain. METHODS ErbB4 conditional KO mice were generated by a lox P/Cre strategy. The experimenter conducting the experimentsand scoring the behavior was blinded to the genotype of the mice. Open field test,Y-maze and novel-object exploration test,novel object recognition task,step-through passive avoidance task,Morris water maze and memory reconsolidation task were carried out in WT and Cdh5-Cre; ErbB4^(loxP/loxP)mice. A high-resolution micro PET/CT scanner was used for brain metabolism imaging. RESULTS Here,we show that Cdh5Cre; ErbB4^(f/f) mice have lower levels ofexploration activity as measured by these particular behavior tests. However,our data indicate that conditional knockout of ErbB4 in endothelial cells did not impair working memory,memory acquisition,retrieval,and reconsolidation in mice. Furthermore,^(18)F-FDG-uptake was reduced in the Cdh5Cre; ErbB4^(f/f) mice as revealed by the significantly decreased SUVs in compared with the WT mice. Consistently,the immunoblot data demonstrate the downregulation of brain Glut1,phosphoULK1(Ser555) and TIGAR in the endothelial ErbB4 conditional knockout mice. Collectively,the endothelial ErbB4 deletion induced impairment in exploratory activity in adult mice,which may be due to the decreased brain energy metabolism. CONCLUSION Our study provides insight into the potential pathophysiological mechanisms of endothelial ErbB 4 and therapeutic strategies for neurological disorders.展开更多
OBJECTIVE To investigate the regulatory effects of icariin(ICA)on cardiac micro⁃vascular endothelial cells(CMEC)after oxygenglucose deprivation reperfusion(OGD/R)injury.METHODS CMEC were subjected to OGD/R treatment t...OBJECTIVE To investigate the regulatory effects of icariin(ICA)on cardiac micro⁃vascular endothelial cells(CMEC)after oxygenglucose deprivation reperfusion(OGD/R)injury.METHODS CMEC were subjected to OGD/R treatment to construct a myocardial ischemiareperfusion model,and were divided into normal,model,low(10μmol·L^(-1)),medium(20μmol·L^(-1))and high(40μmol·L^(-1))ICA group,and high ICA+inhibitor group(40μmol·L^(-1)+20 nmol·L^(-1)).CCK-8 assay was used to assess the protective ability of ICA against CMEC,and cell migration assay and tube-formation assay were used to detect the migration and generation ability of CMEC.The TCMSP database,Swiss-Target database and literature mining methods were used to col⁃lect ICA-related targets,the GeneCards data⁃base was used to collect target genes related to myocardial ischemia/reperfusion,and Cytoscape 3.8.0 software was used to construct a"drug-tar⁃get-disease"network.The potential targets were imported into STRING 11.5 database to obtain the PPI network.GO and KEGG enrichment analyses were performed on the potential targets using the DAVID database.Molecular docking was performed using AutoDock-vina 1.1.2 soft⁃ware.Western blot detected the expression of related proteins.RESULTS After CMEC was subjected to OGD/R treatment,ICA had a protec⁃tive effect at 10^(-1)60μmol·L^(-1);the results of the cell migration assay showed that each group of ICA could promote the migratory effect of CMEC(P<0.01,P<0.01);and the results of tube-for⁃mation assay showed that each group of ICA could significantly promote the generation of branches(P<0.01)and the capillary length exten⁃sion(P<0.05).Network pharmacology collected a total of 23 ICA action targets,1500 disease tar⁃gets and 12 key targets.GO function enrichment analysis found 85 results.KEGG pathway enrich⁃ment analysis found 53 results,involving AGERAGE signaling pathway,sphingolipid signaling pathway and VEGF signaling pathway.Molecu⁃lar docking results showed that ICA had better binding with core targets PRKCB,PRKCA and PTGS2.Western blot results showed that ICA could regulate the expression of PRKCB,PRKCA and PTGS2 proteins.The results of cell migra⁃tion assay,tube-formation assay and protein expression were reversed after addition of PKC inhibitor.CONCLUSION The potential mecha⁃nism of action of ICA against myocardial isch⁃emia-reperfusion injury may be related to the reg⁃ulation of processes such as CMEC migration and angiogenesis,and it functions through the key target gene PKC.展开更多
Objective Vascular endothelial cells senescence is one of major risk factors for atherosclerotic diseases,which can be induced by endogenous peptides,such as angiotensin Ⅱ(Ang Ⅱ).However,the effect of chronic Ang Ⅱ...Objective Vascular endothelial cells senescence is one of major risk factors for atherosclerotic diseases,which can be induced by endogenous peptides,such as angiotensin Ⅱ(Ang Ⅱ).However,the effect of chronic Ang Ⅱ stimulation on endothelial senescence remains unknown.Therefore,this study aims to investigate the changes in morphology and function of human umbilical vein endothelial cells(HUVECs)in response to the chronic stimulation of Ang Ⅱ.展开更多
Instruction Shear stress,caused by the parallel frictional drag force of blood flow,is a biomechanical force which plays an important role in the control of blood vessels growth and functions [1]. Clinical researches ...Instruction Shear stress,caused by the parallel frictional drag force of blood flow,is a biomechanical force which plays an important role in the control of blood vessels growth and functions [1]. Clinical researches had found out that atherosclerotic le-展开更多
文摘Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.
文摘It is well established in experimental animals and Humans that endothelial cells,which cover the luminal surface of all blood vessels,have a pivotal role in the control of vascular homeostasis.The protective effect of endothelial cells is mostly due to their ability to respond to circulating hormones,autacoids,blood-and platelet-derived factors,and also to blood flow by inducing potent vasoprotectivemechanismsincluding predominantlythe formation of nitric oxide(NO),and,often also to some extent,endothelium-derived hyperpolarization,and prostacyclin(PGI2).Besides being a potent vasodilator,NO also effectively prevents platelet activation and has anti-thrombotic and anti-atherosclerotic properties.An endothelial dysfunction characterized by a reduced generation of these endothelium-dependent vasodilator mechanisms associated with vascular oxidative stress and the formation of endothelium-derived contracting factors such as contractile prostanoids is often observed in most types of cardiovascular diseases including hypertension,hypercho⁃lesterolemia,diabetes,and also during physiological ageing in both experimental animals and Humans.Nutrition-derived polyphenols such as those from grapes,tea,cocoa,and berries have been shown to stimulate the endothelial formation of NO by activating the Src/PI3-kinase/Akt-dependent phosphorylation of endothelial NO synthase(eNOS)and to enhance eNOS expression.As a consequence,the active polyphenols will promote a sustained forma⁃tion of NO that contributes to protect the vascular system.Polyphenol-rich products have also been shown to improve an established endothelial dysfunction and to delay the onset of the induction of an endothelial dysfunction in several experimental models of cardiovascular diseases including hypertension and in ageing.Moreover,endothelial senescence characterized by cell cycle arrest and the acquisition of a pro-inflammatory and pro-atherothrombotic phenotype has been identified as an early event promotingthe development of endothelial dysfunc⁃tion.Premature endothelial senescence appears to affect,in particular,arterial sites at risk such as curvatures and bifur⁃cations that are characterized by disturbed flow and low shear stress.The pro-senescent process can be further increased in the presence of a high concentration of glucose,oxidized LDL,and angiotensinⅡ.Anthocyanin-rich products have been shown to accumulate preferentially in senescent endothelial cells,to reduce the expression of cell cycle regulators such as p16,p21 and p53,and to improve the endothelial function.The protective effect is mostly due to their ability to reduce vascular oxidative stress by inhibiting the overexpression of NADPH oxidase and the local angiotensin system.Thus,nutrition-derived polyphenols may be an interesting approach to delay the onset of risk factor-and ageing-related endothelial senescence and dysfunction and,hence,to promote vascular health.
基金supported by Medical Science and Technology Research Project of Henan Province(142102310031)
文摘OBJECTIVE To explore the role of gecko crude peptides(GCPs)in the proliferation,apoptosis,migration and lymphangiogenesis of human hepatocellular carcinoma cells(Hep G2)and human lymphaticendothelial cells(HLECs)in vitro.METHODS The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay was used to evaluate the anti-proliferative effect of GCPs and si RNA-VEGF-C on Hep G2 cells,Hoechst 33258 staining and flow cytometry were performed to analyze cycle and apoptosis.The migration and invasion ability of cells were assayed by transwell chamber experiment and wound-healing assay.The protein and m RNA expressions of vascular endothelial growth factor-C(VEGF-C)and CXC chemokine receptor-4(CXCR4)were detected by q-PCR,immunofluorescence,Western blot.The protein expressions of the extracellular signal regulated kinase(ERKI/2),c-Jun N-terminal kinase(JNK),p38-mitogen activated protein kinases(p38 MAPK),serine/threonine kinase(Akt)and phosphatidylinositol-3-kinase(PI3K)were detected by western blot.The anti-lymphangiogenesis effect of GCPs on the HLECs was analyzed using an in vitro tube-formation assay.The protein and m RNA expressions of vascular endothelial growth factor receptor-3(VEGFR-3)and stromal cell-derived factor-1(SDF-1)were detected by q-PCR,Western blot.RESULTS GCPs and si RNA-VEGF-C inhibited Hep G2 proliferation,invasion and migration,and the most obvious inhibitory effect was both synergistic effects.Thus,GCPs suppressed HLECs proliferation,migration and tubelike structure formationin a dose-dependent manner,and had inhibitory effect of tumor-induced lymphangiogenesis in vitro.Additionally,we found that GCPs and si RNA-VEGF-C decreased the expressions of MMP-2,MMP-9,VEGF-C,CXCR4,phospho-ERK1/2,phospho-P38,phospho-JNK and PI3K in Hep G2 cells.Moreover,GCPs had a dose-dependent depressive effecton the expressions of VEGFR-3,SDF-1 in HLECs.CONCLUSION The low expression of VEGF-C mediated by si RNA-VEGF-C and GCPs inhibit tumor proliferation,invasion and migrationby suppressing the MAPK signaling pathway through reduced levels of VEGF-C,and GCPs inhibit tumor lymphangiogenesis by suppressing the CXCR4/SDF-1 signaling pathway through suppressed VEGF-C/VEGFR-3.
文摘Aim Salidroside （SAL） is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density lipoprotein receptor - deficient mice. This study was to investigate the molecular mechanism of antiatherogenic effects of SAL. Method Six-week old apoE-/- male mice were fed a high-fat diet for 8 weeks and then were ad- ministered with SAL for another 8 weeks. Atherosclerotic lesion and vascular function were analyzed. Primary cul- tured human umbilical vein endothelial cells （HUVECs） were prepared. Superoxide anion （O2^-）, NO produc- tion, mitochondrial membrane potential （△ψm） and intracellular ATP and AMP levels were measured. Expression of eNOS and AMPK were analyzed by Western blot. Result SAL significantly improved endothelial function asso- ciated with increasing eNOS activation thus reduced the atherosclerotic lesion area. SAL increased eNOS-Serl177 phosphorylation and decreased eNOS-Thr495 phosphorylation. SAL significantly activated AMP-activated protein ki- nase （AMPK）. Both AMPK inhibitor and AMPK small interfering RNA （siRNA） abolished SAL-induced Akt- Ser473 and eNOS-Serl177 phosphorylation. In contrast, LY294002, the PI3k/Akt pathway inhibitor, abolished SAL-induced phosphorylation and expression of eNOS. SAL decreased cellular ATP content and increased the cel- lular AMP/ATP ratio, which was associated with the activation of AMPK. SAL was found to decrease A^m, which is likely consequence of reduced ATP production. Conclusion The action of SAL to reduce atherosclerotic lesion formation may at least be attributed to its effect on improving endothelial function by promoting nitric oxide （NO） production, which was associated with mitochondria depolarization and subsequent activation of the AMPK/PI3 IC/ Akt/eNOS pathway. Taken together, our data described the effects of SAL on mitochondria, which played critical roles in improving endothelial function in atherosclerosis.
文摘Objective C1q/TNF-related protein(CTRP)1 was initiallyidentified as a paralog of adiponectin based on the similarity in C1q domain of these two proteins.Previously,we showed that CTRP1promotes the development of atherosclerosis by increasing endothelial adhesiveness.Here,we sought to investigate whether CTRP1 also influences vascular dilatory functions.
基金funded by the National Natural Science Foundation of China ( 31660258, 31771014,31860262,11762006)the Science and Technology Foundation of Guizhou Province ( 2019-2787,2018-1412, 2016-5676,2017-5718)+2 种基金the Science and Technology Innovative Talent Team of Guizhou Province ( 2015-4021)the 2011 Collaborative Innovation Program of Guizhou Province ( 2015-04 )the Cell and Gene Engineering Innovative Research Groups of Guizhou Province ( KY-2016-031)
文摘Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional basis of cells motility,and therefore,from a biomechanical point of view,the purpose of this study is to investigate the effects of FB1 on the biomechanical properties,migration capacity and cytoskeletal structure of human umbilical vein endothelial cells(HUVECs),which may lay an experimental foundation for further exploration of the toxicity mechanism of fumonisin.Methods HUVECs were cultured and treated with different concentrations of FB1.Then,CCK-8 kit was used to detect the effect of FB1 on the survival rate.The osmotic fragility of the cells was measured after treatment with different osmotic pressures for30 min.The cell membrane fluidity was measured by fluorescence polarization method.The cell electrophoretic mobility was measured by cell electrophoretic apparatus.The migration capacity of the cells was observed by scratch repair assay.The changes of reactive oxygen species and cytoskeletal structure were observed by confocal laser scanning microscopy.Finally,the mRNA and protein relative expression levels of cytoskeletal binding proteins were detected by real-time PCR,Western blotting and confocal laser scanning.Results The results of CCK-8 showed that FB1 could significantly inhibit the proliferation of HUVECs in a dose-and time-dependent manner.After treatment of HUVECs with FB1,the hypotonic resistance of the cell,cell surface charge,cell membrane fluidity and migration capacity were all weakened,while reactive oxygen species were significantly increased and the cytoskeletal structure was significantly reorganized.Furthermore,RTPCR results showed that the mRNA relative expression levels of cytoskeletal binding proteins,exception of actin,were down-regulated after treated with FB1.Besides,Western blotting and statistical analysis based on fluorescence intensity of laser confocal microscopy confirmed theses changes in protein level.Conclusions FB1 can significantly affect the biomechanical properties and motility of HUVECs,which may be directly correlated to the remodel of F-actin cytoskeleton,as well as the relative expression changes of cytoskeletal binding proteins.It is significant for further exploring the toxicity mechanism of fumonisin.
基金supported by NIH-1SC1CA153325-01,NSF-MRI CBET 1337746 and 1UG3TR002151-01
文摘Introduction The endothelial cells(ECs)lining every blood vessel wall constantly expose to the mechanical forces generated by the blood flow.The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system.In addition to forming a transport barrier between the blood and vessel wall,vascular ECs play important roles in regulating circulation functions.Besides biochemical stimuli,blood flow induced(hemodynamic)mechanical stimuli,such as shear stress,pressure and circumferential stretch,modulate EC morphology and functions by activating mechanosensors,signaling pathways,and gene and protein expressions.The EC responses to the hemodynamic forces(mechano-sensing and transduction)are critical to maintaining normal vascular functions.Failure in the mechano-sensing and transduction leads to serious vascular diseases including hypertension,atherosclerosis,aneurysms and thrombosis,to name a few[1].On the luminal surface of our blood vessels,there is a thin layer called endothelial surface glycocalyx(ESG)which consists of proteoglycans,glycosaminoglycans(GAGs)and glycoproteins.The GAGs in the ESG are heparan sulfate(HS),hyaluronic acid(HA),chondroitin sulfate(CS),and sialic acid(SA)[2].In order to play important roles in vascular functions,such as being a mechanosensor and transducer for the endothelial cells(ECs)to sense the blood flow,a molecular sieve to maintain normal microvessel permeability and a barrier between the circulating cells and endothelial cells forming the vessel wall,the ESG should have an organized structure at the molecular level.Due to the limitations of optical and electron microscopy,the ultra-structure and organization of ESG has not been revealed until recent development of a super high resolution fluorescence optical microscope,STORM(Stochastic Optical Reconstruction Microscopy).The diffraction of a single fluorescence molecule can be described as the point spread function(PSF).When the light of wavelengthλexcites the fluorophore(emitter),the intensity profile of the spot is defined as the PSF with the width^0.6λ/NA,NA is the numerical aperture of the objective.The diffraction-limited image resolution,for a high numerical aperture objective lens,is^200 nm in the lateral direction and^500 nm in the axial direction,for a conventional fluorescence microscope.The key idea of the single-molecule localization microscopy is to light the molecule,in turn,to achieve the nanometer-level accuracy of their position and reconstruction into a super-resolution image,such as STORM.STORM employs photo-switching mechanisms to stochastically activate individual molecules(photo-switchable or photoactivatable fluorophores)within the diffraction-limited region at different times.Then images with sub-diffraction limit resolution are reconstructed from the measured positions of individual fluorophores[3].To trade the super spatial resolution(accuracy),STORM sacrifices its temporal resolution(efficiency)by switching the state and sequentially exciting the emitters at a high density.Rust et al[3]employed organic dyes and fluorescent proteins as photo-switchable emitters to trade temporal resolution for a super spatial resolution(~20 nm lateral and^50 nm axial at present,can go down to a couple of nanometers if using smaller peptides or antibody fragments instead of currently used whole anti-bodies),which is an order of magnitude higher than conventional confocal microscopy.In the current study,we employed STORM to reveal the major ultra-structural components of the ESG,HS and HA,and their organization at the surface of the cultured EC monolayer[4].Materials and methods We used newly acquired Nikon-STORM system to observe the ESG on in vitro EC(bEnd3,mouse brain microvascular endothelial cells)monolayers.After confluency,the bEnd3 cells were immunolabeled with anti-HS,fol-lowed by an ATT0488 conjugated goat anti-mouse IgG,and with biotinylated HA binding protein,followed by an AF647 conjugated anti-biotin.The ESG was then imaged by the STORM with a 100x/1.49 oil immersed lens.Multiple Reporters of ATT0488 and AF647 with alternating illumination were used to acquire the 3D images of HS and HA.The field of 256×256(40×40μm2)of HS and HA at the surface of ECs was obtained based on totally 40,000 of EM-CCD captured images for each reporter at a capturing speed of 19 ms/frame.Results HA is a long molecule weaving into a network which covers the endothelial luminal surface.The diameter of the HA segments is 185.3±44.7 nm,155.5±57.2 nm,and 156.9±56.1 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.In contrast,HS is a shorter molecule,perpendicular to the cell surface.HA and HS are partially overlapped with each other at the endothelial luminal surface.We quantified the length,diameter,orientation,and density of HS at the top,middle and bottom regions of the endothelial surface.The diameter of the observed HS is 191.0±46.0 nm,284.3±71.1 nm,and 184.2±59.6 nm,and the length of the HS is 621.0±75.7 nm,651.0±118.0 nm,and 575.2±105.6 nm,respectively,at the top,middle and bottom regions of the cell luminal surface.For the HS orientation,its angle with the cell surface is 92.9±1.9,88.7±8.2,and 96.2±10.9 degree,respectively,at the top,middle and bottom regions.The angle of 90 degree is perfectly perpendicular to the cell surface.For the HS distribution,the average density is0.398 elements/μm2,0.345 elements/μm2 and 0.665 elements/μm2,respectively,and the distance between the adjacent HS is 1 694.4±628.1 nm,1 844.8±758.5 nm,and 1 221.9±450.7 nm,respectively,at the top,middle and bottom regions.Conclusions Our results suggest that HS plays a major role in mechanosensing and HA plays a major role in the molecular sieve,due to their organization,ultra-structure and distribution.
基金Project Supported By the National Natural Science Fund
文摘Human endothelial cells derived from umbilical vein could besubcultured and survive 25 passage (double time 20～25 hours, 60～75 cumula-tive population doublings). An observation was performed with light mi-croscopy, electron microscopy and immunofluorescence microscopy using specificantiserum against factor Ⅷrelated antigen. It identified that the cultured cellswere endothelial cells. Medium RPMI-1640 supplemented with 20% humanserum, endothelial cell growth factor 200μg/ml, heparin 100μg/ml and gelatincoated flasks were very important conditions for long-term culture of humanendothelial cell.
基金supported by funds from Huazhong University of Science and Technology
文摘The technology of induced pluripotent stem cell(iPSCs)has enabled the conversion of somatic cells into primitive undifferentiated cells via reprogramming.This approach provides possibilities for cell replacement therapies and drug screening,but the potential risk of tumorigenesis hampers further development and application.How to generate required differentia-ted cells without initiating tumor progression remains a huge challenge.Here we show that mouse embryonic fibroblasts could be differentiated into valvular endothelial cell(VEC)like cells.VECs are critical in valve replacements in aortic valve failure.VEC-associated gene and protein expression and functional assays were quantified for these VEC-like cells.We show that mouse embryonic fibroblasts could be converted into VEC-like cells.Our results suggest that it is possible to convert mouse embryonic fibroblasts into VEC-like cells without first reprogramming them into pluripotent stem cells,minimizing the possibility of tumorigenesis.
基金The project supported by the National Science Council of Cinese Taipei(NSC102-2320-B-039-058)China Medical University,Chinese Taipei(CMU102-N-02and CMU103-N-08)
文摘OBJECTIVE Highly electronegative L5 low-density lipoprotein(LDL),an atherogenic LDL,induces endothelial cell(EC)senescence and has been implicated in the progression of atherosclerosis.We examine whether sesamol,a natural organic compound and component of sesame oil,prevents EC senescence induced by electronegative LDL(L5)and to investigate the underlying mechanisms.METHODS Syrian hamsters,which have a LDL profile similar to that of humans,were fed a normal chow diet(control),a high-fat diet(HFD),or a HFD supplemented with the administration of 50 or 100mg·kg-1 sesamol via oral gavage(HFD+sesamol)for 16 weeks(n=10 per group).Among these groups,we compared plasma L5 levels and aortic endothelial senescence in the aortic arch.In vitro,we examined the effects of sesamol on human aortic endothelial cell(HAEC)senescence and signaling pathways induced by L5.RESULTS Hamsters in the HFD group had higher plasma L5 levels than did the HFD+sesamol groups or control group.Betagalactosidase(gal)staining showed that aortic endothelial senescence was markedly increased in the aortic arch of the HFD group but not in that of the HFD+sesamol groups when compared with the control group.In vitro,treatment of HAECs with sesamol(1-3mol·L-1)blocked L5-induced EC senescence in a dose-dependent manner.Sesamol also markedly inhibited the L5-induced phosphorylation of p38 MAPK and p53 activation and increased Mdm2 and phosphorylation of Akt.CONCLUSION The critical findings of this study suggest that sesamol may provide protection against atherosclerosis and the development of cardiovascular disease in humans.
基金supported by grants ( 11421202,11572029) from National Natural Science Foundation of China
文摘Introduction Primary cilium is a non-motile microstructure,protruding from cell surface of most mammalian cells.It was previously thought to be vestigial.However,recent studies indicate that it may serve as one of the most vital mechanosensors for many types of cells such as epithelial and endothelial cells and osteocytes.Protruding from the apical membrane,the primary cilium can directly sense subtle variation of mechanical forces exerted on the cell and then transduce the mechanical cues into biochemical signals into the cell,although the mechanism remain elusive.Vascular endothelial cells(ECs)lining the inner wall of our blood vessels are continuously exposed to the blood flow.In order to maintain proper functions for the cardiovascular system,ECs should have a variety of mechano-sensors and transducers to sense the blood flow change and adjust the vessel size and transport across the vessel wall accordingly.Among more than a dozen recognized EC mechano-sensors,the primary cilium has drawn more and more attention recently.Primary cilium on endothelial cells is essential for the homeostasis of vessels.It is reported to be prevalent in areas of disturbed flow where atherosclerosis and intracranial aneurysm usually occur.Deficiencies of primary cilia may promote atherosclerosis,endothelial-to-mesenchymal transition(EndoMT)and loss of direction orientation,to name a few.Therefore understanding why the primary cilia are necessary to maintain the homeostasis of blood vessels and how will help us develop better treatment strategies for the common cardiovascular diseases.Dimension and structure of primary cilium Primary cilium is reported to be shorter than 8 in length and about 0.2 in diameter.The length of primary cilium varies in different cell types and under different conditions.The major structural components of the primary cilium include basal body,ciliary axoneme(consisting of nine doublet microtubules),ciliary membrane,transition zone,basal feet,and striated rootlets.Each part of the primary cilium is essential and has specific function.Current methods investigating the EC primary cilium as a mechano-sensor:Immunostaining and imaging techniques have been used to investigate the molecular mechanisms by which EC primary cilium serves as a mechano-sensor and transducer.It has been found that various proteins locate on the primary cilium,working together to maintain the function of primary cilium.Some proteins function as ion-channels,mediating Ca2+entry into the primary cilium.Some are involved in the cascade signal pathway.Others are related to the assembly and maintenance of primary cilium.Briefly,the flow induces the deflection of the EC primary cilium,which triggers calcium increase via opening of the PC2 cation channel that is responsible for calcium ion influx.This PC2 cation channel is localized to the primary cilium and is assumed to be stretch-activated.The resulting change in the intracellular calcium concentration then regulates numerous molecular activities inside the cell that contribute to vessel homeostasis.In addition to triggering calcium release,another mechanism has also been found in blood-pressure maintenance in the vasculature,where the vessel diameter is regulated by endothelial primary cilia through adjusting nitric oxide production.So far,little is known about the mechanical mechanism behind this deflection-triggered o-pening of signaling pathways.For example,what is the flow induced bending behavior and force distribution? What is the threshold value of stretch/defection for activating a corresponding signaling pathway? These all remain to be answered.In combination of image data and experiments,several computational models have been established to answer these questions.However,the current models are not able to include the complex structure of primary cilium and the model predictions are limited.Future studies With the development of super high resolution optical microscopy,more detailed images for the structural(molecular)components of EC primary cilia will be revealed,especially when the ECs are alive and the forces are known.Combining these experimental observations with more sophisticated mathematical models will elucidate the mechano-sensing mechanism of EC primary cilia,as the force and stress distribution on cilium along with other mechanical properties are still beyond the capability of experimental approaches due to the scales of the quantities involved.By using numerical approaches,much more detailed dynamic information can be obtained.
文摘Aim Alpha7 nicotinic acetylcholine receptor （α7nAChR）, a subtype of nAChR regulating neurotrans- mission in central nervous system, is an essential regulator of cholinergic antiinflammatory pathway in periphery. The present study was to determine the effects of activation of α7nAChR on oxidant stress-induced injury in endo- thelial cells. Methods Cultured human umbilical vein endothelial cells were treated with H202 （400 μmol · L^-1） or H202plus PNU-282987 （ 10 μmol · L^-1 ）. Cell viability and membrane integrity were measured. AnnexinV ＋ PI assay, immunoblotting of bcl-2, bax and cleaved caspase-3, and immunofluorescence of apoptosis inducing factor （AIF） were performed to evaluate apoptosis. Protein expression of vascular peroxidase-1 （ VPO-1 ） and phosphor- JNK were measured by immunoblotting. Results Activation of α7nAChR by a selective agonist PNU-282987 pre-vented H202-indced decrease of cell viability and increase of lactate dehydrogenase release. Activation of α7nAChR markedly reduced cell apoptosis and intracellular oxidative stress level. Moreover, activation of α7nAChR reduced H2 02 -induced VPO-1 protein upregulation and JNK1/2 phosphorylation. The inhibitory effect of α7nAChR activa- tion on VPO-1 was blocked by JNK inhibitor SP600125. In addition, pretreatment of α7nAChR antagonist methyl- lycaconitine blocked the cytoprotective effect of PNU-282987. Conclusion These results provide the first evidence that activation of α7nAChR protects against oxidant stress-induced damage by suppressing VPO-1 in a JNK signa- ling pathway-dependent manner in endothelial cells.
文摘Aim Magnesium lithospermate B （MLB） is the most abundant hydrophilic active component of Salvia rniltiorrhiza Radix, a traditional Chinese herbal medicine mainly used to treat cardiovascular diseases. Studies have shown that endothelial activation contributes to the pathophysiology of cardiovascular diseases such as atherosclero- sis, diabetic vasculopathy, heart failure and hypertension. In the present study, the effects of MLB on endothelial activation were investigated. Lipopolysaccharide （LPS） 1 mg L^-1 was employed to induce endothelial activation, which was determined by relative gene expression and endothelial adhesion assay. Results showed that pretreatment with MLB attenuated LPS-induced ICAM1, VCAM1 and TNF-α upregulation in human dermal microvascular endo- thelial cells （HMEC-1） in dose-dependent manner, which contributed to the reduction of THP-1 adhesion to HMEC-1. Furthermore, it was revealed that 100 μmol · L^-1 MLB significantly decreased the nuclear translocation of NF-KB p65, a critical transcription factor in LPS-indueed inflammatory response, through the inhibition of IKBμ degradation. Besides, the transcriptional activity of NF-KB p65 was also inhibited by the pretreatment of MLB. Mo- reover, MLB pretreatment considerably inhibited LPS-induced p38 phosphorylation, which at least partly contribu- ted to the reduction of ICAM1 expression. In conclusion, these findings suggest that MLB inhibits LPS-induced nu- clear translocation and transcripitional activity of NF-KB, thus attenuates the increased expression of adhesion mole- cules and inflammatory factors, protects endothelial cells from LPS-induced activation.
文摘OBJECTIVE This study was aimed to evaluate the effect of mangosteen peel extract(MPE)on migration of human umbilical vein endothelial cells(HUVECs)treated with LPS.METHODS Cultured HUVECs were divided into five groups:normal(untreated)group,positive control group treated with LPS at dose of 20ng·mL-1 for 24 h,and groups pre-treated with LPS at dose of 20ng·mL-1 for 24 h followed by incubation with MPE at doses of 1,2,and 4-1μg·mL,respectively.HUVECs migration was evaluated using wound-healing migration assay after 24 h of treatment.RESULTS LPS significantly(P<0.05)impaired HUVECs migration compared to the normal.MPE at dose of 1μg·mL-1 increased migration of LPS-treated HUVECs significantly(P<0.05)compared to the positive control and near to the normal level.CONCLUSION The mangosteen peel extract is able to dose-dependently preserve the endothelial cells function.
文摘Aim Premature senescence of the vascular endothelial cells is a leading cause of endothelial dysfunc- tion. Our previous observations suggest that up-regulation of heme oxygenase-1 （HO-1） improves endothelial func- tion by attenuating endothelium-dependent contractions and potentiating endothelium-dependent hyperpolarization. The present study aimed to investigate the effect of HO-1 on endothelial senescence and the underlying mecha- nisms. Methods Human umbilical vein endothelial cells （HUVEC） were treated with 50 μmol · L^-1 H2 02 to in- duce premature senescence. HO-1 was up-regulated by the pharmacological inducer hemin, whereas it was knocked down by 1RNA silencing. Results H2 02 remarkably induced HUVEC senescence as detecting by the immunostain- ing of senescence-associated β-galactosidase. Overexpression of HO-1 by hemin reversed H2 02 -induced senescence in a dose-dependent manner. Silencing of HO-1 triggered HUVEC senescence, even in the absence of H202. In addition, HO-1 induction prevented the decrease of eNOS phosphorylation at Serine 1177 stimulated by H202. Contrarily, HO-1 silencing impaired eNOS phosphorylation. The total protein expression of eNOS was not altered by HO-1. Further, co-immunoprecipitation experiments showed that HO-1 directly interacted with eNOS. Conclusions HO-1 ameliorated endothelial senescence probably through interacting with eNOS and affecting its phosphoryla- tion modification.
基金The project supported by National Natural Science Foundation of China(81230082,81302771,81525025,81573422,81500226)Natural Science Foundation of Guangdong Province(2014A030313087)by Science and Technology program of Guangzhou City(201607010255)
文摘OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TMEM16A in the vascular endothelial dysfunction in hypertension is unclear.METHODS In the study,RT-PCR,Western blotting,co-immunopricipitation,confocal imaging,patch-clamp,and endothelial-specific TMEM16A transgenic and knockout mice were employed.RESULTS We found that TMEM16A was expressed abundantly and functioned as Ca CC in endothelial cells.AngiotensinⅡ(AngⅡ)induced endothelial dysfunction with an increase in TMEM16A expression,which was alleviated by TMEM16A inhibitor.Further studies revealed that TMEM16A endothelial-specific knockout significantly lowered the blood pressure and ameliorated endothelial dysfunction in AngⅡ-induced hypertension,whereas,TMEM16A endothelial-specific overexpression showed the opposite effects.These results were related to the increased reactive oxygen species(ROS)generation,NADPH oxidase activation,and Nox2,p22phox expression facilitated by TMEM16A upon AngⅡ-induced hypertensive challenges.Moreover,TMEM16A directly interacted with Nox2 monomer and reduced the degradation of Nox2 through the proteasome-dependent endoplasmic recticulum-associated degradation pathway.TMEM16A also potentiated the translocation of p47phox and p67phox from cytosol to cell membrane and the subsequent interaction with Nox2.CONCLUSION Our results demonstrated that TMEM16A,as Ca CC,is a positive regulator of ROS generation via upregulating the activation of Nox2 NADPH oxidase in the vascular endothelium,and therefore facilitates endothelial dysfunction and hypertension.Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated cardiovascular diseases.
文摘OBJECTIVE The receptor-tyrosine kinase ErbB4 is present throughout the primate brain and has a distinct functional profile.In the present study,we investigate the potential role of endothelial ErbB4 receptor signaling in the brain. METHODS ErbB4 conditional KO mice were generated by a lox P/Cre strategy. The experimenter conducting the experimentsand scoring the behavior was blinded to the genotype of the mice. Open field test,Y-maze and novel-object exploration test,novel object recognition task,step-through passive avoidance task,Morris water maze and memory reconsolidation task were carried out in WT and Cdh5-Cre; ErbB4^(loxP/loxP)mice. A high-resolution micro PET/CT scanner was used for brain metabolism imaging. RESULTS Here,we show that Cdh5Cre; ErbB4^(f/f) mice have lower levels ofexploration activity as measured by these particular behavior tests. However,our data indicate that conditional knockout of ErbB4 in endothelial cells did not impair working memory,memory acquisition,retrieval,and reconsolidation in mice. Furthermore,^(18)F-FDG-uptake was reduced in the Cdh5Cre; ErbB4^(f/f) mice as revealed by the significantly decreased SUVs in compared with the WT mice. Consistently,the immunoblot data demonstrate the downregulation of brain Glut1,phosphoULK1(Ser555) and TIGAR in the endothelial ErbB4 conditional knockout mice. Collectively,the endothelial ErbB4 deletion induced impairment in exploratory activity in adult mice,which may be due to the decreased brain energy metabolism. CONCLUSION Our study provides insight into the potential pathophysiological mechanisms of endothelial ErbB 4 and therapeutic strategies for neurological disorders.
基金National Natural Science Foundation of China(82030124)National Natural Science Foundation of China(82174015)Science and Technology Innovation Project of China Academy of Traditional Chinese Medicine(CI2021A04609)。
文摘OBJECTIVE To investigate the regulatory effects of icariin(ICA)on cardiac micro⁃vascular endothelial cells(CMEC)after oxygenglucose deprivation reperfusion(OGD/R)injury.METHODS CMEC were subjected to OGD/R treatment to construct a myocardial ischemiareperfusion model,and were divided into normal,model,low(10μmol·L^(-1)),medium(20μmol·L^(-1))and high(40μmol·L^(-1))ICA group,and high ICA+inhibitor group(40μmol·L^(-1)+20 nmol·L^(-1)).CCK-8 assay was used to assess the protective ability of ICA against CMEC,and cell migration assay and tube-formation assay were used to detect the migration and generation ability of CMEC.The TCMSP database,Swiss-Target database and literature mining methods were used to col⁃lect ICA-related targets,the GeneCards data⁃base was used to collect target genes related to myocardial ischemia/reperfusion,and Cytoscape 3.8.0 software was used to construct a"drug-tar⁃get-disease"network.The potential targets were imported into STRING 11.5 database to obtain the PPI network.GO and KEGG enrichment analyses were performed on the potential targets using the DAVID database.Molecular docking was performed using AutoDock-vina 1.1.2 soft⁃ware.Western blot detected the expression of related proteins.RESULTS After CMEC was subjected to OGD/R treatment,ICA had a protec⁃tive effect at 10^(-1)60μmol·L^(-1);the results of the cell migration assay showed that each group of ICA could promote the migratory effect of CMEC(P<0.01,P<0.01);and the results of tube-for⁃mation assay showed that each group of ICA could significantly promote the generation of branches(P<0.01)and the capillary length exten⁃sion(P<0.05).Network pharmacology collected a total of 23 ICA action targets,1500 disease tar⁃gets and 12 key targets.GO function enrichment analysis found 85 results.KEGG pathway enrich⁃ment analysis found 53 results,involving AGERAGE signaling pathway,sphingolipid signaling pathway and VEGF signaling pathway.Molecu⁃lar docking results showed that ICA had better binding with core targets PRKCB,PRKCA and PTGS2.Western blot results showed that ICA could regulate the expression of PRKCB,PRKCA and PTGS2 proteins.The results of cell migra⁃tion assay,tube-formation assay and protein expression were reversed after addition of PKC inhibitor.CONCLUSION The potential mecha⁃nism of action of ICA against myocardial isch⁃emia-reperfusion injury may be related to the reg⁃ulation of processes such as CMEC migration and angiogenesis,and it functions through the key target gene PKC.
文摘Objective Vascular endothelial cells senescence is one of major risk factors for atherosclerotic diseases,which can be induced by endogenous peptides,such as angiotensin Ⅱ(Ang Ⅱ).However,the effect of chronic Ang Ⅱ stimulation on endothelial senescence remains unknown.Therefore,this study aims to investigate the changes in morphology and function of human umbilical vein endothelial cells(HUVECs)in response to the chronic stimulation of Ang Ⅱ.
基金supported by grants from the National Natural Science Foundation of China,Nos10732070,10702043,30970703,10972140 and 30470432
文摘Instruction Shear stress,caused by the parallel frictional drag force of blood flow,is a biomechanical force which plays an important role in the control of blood vessels growth and functions [1]. Clinical researches had found out that atherosclerotic le-
