Skin wounds are characterized by injury to the skin due to trauma,tearing,cuts,or contusions.As such injuries are common to all human groups,they may at times represent a serious socioeconomic burden.Currently,increas...Skin wounds are characterized by injury to the skin due to trauma,tearing,cuts,or contusions.As such injuries are common to all human groups,they may at times represent a serious socioeconomic burden.Currently,increasing numbers of studies have focused on the role of mesenchymal stem cell(MSC)-derived extracellular vesicles(EVs)in skin wound repair.As a cell-free therapy,MSC-derived EVs have shown significant application potential in the field of wound repair as a more stable and safer option than conventional cell therapy.Treatment based on MSC-derived EVs can significantly promote the repair of damaged substructures,including the regeneration of vessels,nerves,and hair follicles.In addition,MSC-derived EVs can inhibit scar formation by affecting angiogenesis-related and antifibrotic pathways in promoting macrophage polarization,wound angiogenesis,cell proliferation,and cell migration,and by inhibiting excessive extracellular matrix production.Additionally,these structures can serve as a scaffold for components used in wound repair,and they can be developed into bioengineered EVs to support trauma repair.Through the formulation of standardized culture,isolation,purification,and drug delivery strategies,exploration of the detailed mechanism of EVs will allow them to be used as clinical treatments for wound repair.In conclusion,MSCderived EV-based therapies have important application prospects in wound repair.Here we provide a comprehensive overview of their current status,application potential,and associated drawbacks.展开更多
BACKGROUND: Small extracellular vesicles (sEVs) from bone marrow mesenchymal stemcells (BMSCs) have shown therapeutic potential for cerebral ischemic diseases. However, themechanisms by which BMSC-derived sEVs (BMSC-s...BACKGROUND: Small extracellular vesicles (sEVs) from bone marrow mesenchymal stemcells (BMSCs) have shown therapeutic potential for cerebral ischemic diseases. However, themechanisms by which BMSC-derived sEVs (BMSC-sEVs) protect neurons against cerebral ischemia/reperfusion (I/R) injury remain unclear. In this study, we explored the neuroprotective effects ofBMSC-sEVs in the primary culture of rat cortical neurons exposed to oxygen-glucose deprivation andreperfusion (OGD/R) injury.METHODS: The primary cortical neuron OGD/R model was established to simulate the processof cerebral I/R in vitro. Based on this model, we examined whether the mechanism through whichBMSC-sEVs could rescue OGD/R-induced neuronal injury.RESULTS: BMSC-sEVs (20 μg/mL, 40 μg/mL) significantly decreased the reactive oxygenspecies (ROS) productions, and increased the activities of superoxide dismutase (SOD) and glutathioneperoxidase (GPx). Additionally, BMSC-sEVs prevented OGD/R-induced neuronal apoptosis in vivo, asindicated by increased cell viability, reduced lactate dehydrogenase (LDH) leakage, decreased terminaldeoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining-positivecells, down-regulated cleaved caspase-3, and up-regulated Bcl-2/Bax ratio. Furthermore, Westernblot and flow cytometry analysis indicated that BMSC-sEV treatment decreased the expression ofphosphorylated calcium/calmodulin-dependent kinase II (p-CaMK II)/CaMK II, suppressed the increaseof intracellular calcium concentration ([Ca2+]i) caused by OGD/R in neurons.CONCLUSIONS: These results demonstrate that BMSC-sEVs have signifi cant neuroprotectiveeff ects against OGD/R-induced cell injury by suppressing oxidative stress and apoptosis, and Ca2+/CaMK II signaling pathways may be involved in this process.展开更多
Extract of oven dried leaves of Pongamia pinnata(L) Pierre was used for the synthesis of silver nanoparticles. Stable and crystalline silver nanoparticles were formed by the treatment of aqueous solution of AgNO_3(1m ...Extract of oven dried leaves of Pongamia pinnata(L) Pierre was used for the synthesis of silver nanoparticles. Stable and crystalline silver nanoparticles were formed by the treatment of aqueous solution of AgNO_3(1m M) with dried leaf extract of Pongamia pinnata(L) Pierre. UV-visible spectroscopy studies were carried out to quantify the formation of silver nanoparticles. Transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the silver nanoparticles. TEM image divulges that silver nanoparticles are quite polydispersed, the size ranging from 20 nm to 50 nm with an average of 38 nm. Water soluble heterocyclic compounds such as flavones were mainly responsible for the reduction and stabilization of the nanoparticles. Silver nanoparticles were effective against Escherichia coli(ATCC 8739), Staphylococcus aureus(ATCC 6538p), Pseudomonas aeruginosa(ATCC 9027) and Klebsiella pneumoniae(clinical isolate). The move towards extracellular synthesis using dried biomass appears to be cost effective, eco-friendly to the conventional methods of nanoparticles synthesis.展开更多
Extracellular vesicles(EVs)are cell-derived membranous particles that play a crucial role in molecular trafficking,intercellular transport and the egress of unwanted proteins.They have been implicated in many diseases...Extracellular vesicles(EVs)are cell-derived membranous particles that play a crucial role in molecular trafficking,intercellular transport and the egress of unwanted proteins.They have been implicated in many diseases including cancer and neurodegeneration.EVs are detected in all bodily fluids,and their protein and nucleic acid content offers a means of assessing the status of the cells from which they originated.As such,they provide opportunities in biomarker discovery for diagnosis,prognosis or the stratification of diseases as well as an objective monitoring of therapies.The simultaneous assaying of multiple EV-derived markers will be required for an impactful practical application,and multiplexing platforms have evolved with the potential to achieve this.Herein,we provide a comprehensive overview of the currently available multiplexing platforms for EV analysis,with a primary focus on miniaturized and integrated devices that offer potential step changes in analytical power,throughput and consistency.展开更多
Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-N...Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.展开更多
Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A ...Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A cell suspension culture was initiated from callus derived from plantlets of Populus euphratica. Cold acclimation was induced (LT50 of 17.5 ℃) in cell suspension at 45 ℃ in the dark for 30 days and the freezing tolerance increased from LT50 of 12.5 ℃ in nonacclimated cells to LT50 of 17.5 ℃ in cold-acclimated cells. Microvacuolation, cytoplasmic augmentation and accumulation of starch granules were observed in cells that were cold-acclimated by exposure to low temperatures. Several qualitative and quantitative changes in proteins were noted during cold acclimation. Antibodies to carrot extracellular (apoplastic) 36 kD antifreeze protein did not cross react on immunoelectroblots with extracellular proteins in cell suspension culture medium of Populus euphratica, indicating no common epitopes in the carrot 36 kD antifreeze protein and P. euphratica extracellular proteins. The relationship of these changes to cold acclimation in Populus euphratica cell cultures was discussed.展开更多
Cardiovascular aging is a physiological process gradually leading to structural degeneration and functional loss of all the cardiac and vascular components. Conduction system is also deeply influenced by the aging pro...Cardiovascular aging is a physiological process gradually leading to structural degeneration and functional loss of all the cardiac and vascular components. Conduction system is also deeply influenced by the aging process with relevant reflexes in the clinical side. Age-related arrhythmias carry significant morbidity and mortality and represent a clinical and economical burden. An important and unjustly unrecognized actor in the pathophysiology of aging is represented by the extracellular matrix （ECM） that not only structurally supports the heart determining its mechanical and functional properties, but also sends a biological signaling regulating cellular function and maintaining tissue homeostasis. At the biophysical level, cardiac ECM exhibits a peculiar degree of anisotropy, which is among the main determinants of the conductive properties of the specialized electrical conduction system. Age-associated alterations of cardiac ECM are therefore able to profoundly affect the function of the conduction system with striking impact on the patient clinical conditions. This review will focus on the ECM changes that occur during aging in the heart conduction system and on their translation to the clinical scenario. Potential diagnostic and therapeutical perspectives arising from the knowledge on ECM age-associated alterations are further discussed.展开更多
Objective：Hyperglycemia stimulates secretion of transforming growth factor-βl （TGF-βl） in cultured glomerular mesangial cells, thereby increases production of extracellular matrix （ECM）. We examined the effect ...Objective：Hyperglycemia stimulates secretion of transforming growth factor-βl （TGF-βl） in cultured glomerular mesangial cells, thereby increases production of extracellular matrix （ECM）. We examined the effect of antisense mRNA for Smad2 on high glucose-induced ECM production in rat mesangial cells. Methods..A mammalian expression vector, pES2a, which expresses antisense Smad2 mRNA and green fluorescent protein （EGFP）, was transfected into mesangial cells. Following incubation in high glucose medium, EGFP expression and Smad2 mRNA level were determined by fluorescence microscopy and PCR, respectively. Secreted fibronectin and type IV collagen were assessed by enzyme-linked immunosorbent assay. Results ：Within 48 h of incubation in high glucose medium, Smad2 mRNA level significantly increased by 1.6 fold in association with increases in prodtaction of both fibronectin （from [45.86±2.73] to [84.19±6.81] ng/ml） and type IV collagen （from [16. 28±0. 90] to [55.27±4.75] ng/ml） in nontransfected cells （P〈0.05）. In pES2a-transfected cells, the high glucose-induced increase in Smad2 mRNA was abrogated completely, in parallel with significant suppression of the high glucose-indtmed increase in fibronectinproduction （[54.44±4.99] ng/ml） and type Ⅳ collagen （[20.96±2.47] ng/ml）. An empty vector was without effects. Coneluslon：These findings demonstrate that Smad2 plays a critical role in mediating high glucose-stimulated ECM production in mesangial cells, indicating that inhibition of Smad2 activity by antisense Smad2 mRNA may be an effective means to attenuate glomerular matrix accumulation in diabetic nephropathy.展开更多
Extracellular RNAs(exRNAs) are novel circulating factors that can be used as biomarkers in various diseases. Their unique and diverse kinds, as well as their role as biomarkers, make them significant biomarkers. There...Extracellular RNAs(exRNAs) are novel circulating factors that can be used as biomarkers in various diseases. Their unique and diverse kinds, as well as their role as biomarkers, make them significant biomarkers. There has been immense work carried out since the discovery of exRNAs in circulation and other biological fluids to catalog and determine whether exRNAs may be utilized as indicators for health and illness. In this review, we aim to understand the current state of exRNAs in relation to various diseases and their potential as biomarkers. We will also review current issues and challenges faced in using exRNAs, with clinical and lab trials, that can be used as viable markers for different diseases.展开更多
Changbai Mountain,central in the distribution of Pinus koraiensis,supports a virgin Korean pine forest with vertical gradient distribution.Soil extracellular enzyme activity(EEA) and enzyme stoichiometry(ES) are relia...Changbai Mountain,central in the distribution of Pinus koraiensis,supports a virgin Korean pine forest with vertical gradient distribution.Soil extracellular enzyme activity(EEA) and enzyme stoichiometry(ES) are reliable indicators of the energy and nutrients utilized by microbial communities and of soil nutrient changes.We measured four representative soil EEAs(sucrase,cellulase,urease,acid phosphatase) at two soil layers(A:0-5 cm and B:5-10 cm)beneath Korean pine forest at five elevations on Changbai Mountain during growing season.The vertical and seasonal variations of EEAs were analyzed by soil enzyme stoichiometry to quantify the role of soil microorganism in the nutrient cycling process.The activities of four soil extracellular enzymes and the ratios of enzyme activity to soil microbial biomass carbon(EA/SMBC) did not vary with elevation.The first partition point of multiple regression trees was in September,and the second branch was split by elevation.Seasonal change had more influence on soil enzyme activity(A layer:75.6%;B layer:71.3%) than did change in elevation(A layer:7.8%;B layer:7.5%).Over one entire growing season,both vector length and vector angle were unchanged by elevation,but varied significantly by month.Among the soil physicochemical factors,available phosphorus and pH were the main factors affecting the four soil EE As.The ratio of basal area of the coniferous tree to broad-leaved tree species(S_(con)/S_(br)),soil microbial biomass carbon(MBC) and nitrogen(MBN) influenced the four soil EE As.The results of vector analysis revealed that C and N sources were generally sufficient,but P was limiting(vector angle> 45°).The vector angle for September was significantly higher than for other months.This result verified that phosphorus was the limiting factor affecting soil microorganism function in nutrient metabolism and cycling.Soil enzyme stoichiometry proved to be an efficient index for quantifying soil microorganismmediated nutrient cycling in the Korean pine ecosystem.展开更多
Objective To investigate the correlation between drinking behavior combined with polymorphisms of extracellular superoxide dismutase （EC-SOD） and aldehyde dehydrogenase-2 （ALDH2） genes and pancreatic cancer. Meth...Objective To investigate the correlation between drinking behavior combined with polymorphisms of extracellular superoxide dismutase （EC-SOD） and aldehyde dehydrogenase-2 （ALDH2） genes and pancreatic cancer. Methods The genetic polymorphisms of EC-SOD and ALDH2 were analyzed by polymerase chain reaction restriction fragment length polymorphism in the peripheral blood leukocytes obtained from 680 pancreatic cancer cases and 680 non-cancer controls. Subsequently the frequency of genotype was compared between the pancreatic cancer patients and the healthy controls.The relationship of drinking with pancreatic cancer was analyzed. Results The frequencies of EC-SOD （C/G） and ALDH2 variant genotypes were 37.35% and 68.82% respectively in the pancreatic cancer cases, and were significantly higher than those in the healthy controls （21.03% and 44.56%, all P〈0.01）. People who carried EC-SOD （C/G） （0R=2.24, 95% C1= 1.81-4.03, P〈0.01） or ALDH2 variant genotypes （OR=2.75, 95% CI=1.92-4.47, P〈0.01） had a high risk to develop pancreatic cancer. Those who carried EC-SOD （C/G） genotype combined with ALDH2 variant genotype had a high risk for pancreatic cancer （29.56% vs. 6.76%, 0R=7.69, 95% CI=3.58-10.51, P〈0.01）. The drinking rate of the pancreatic cancer group （64.12%） was significantly higher than that of the control group （40.15%; OR=2.66, 95% CI=1.30-4.42, P〈0.01）. An interaction between drinking and EC-SOD （C/G）/ALDH2 variant genotypes increased the risk of occurrence of pancreatic cancer （OR=25.00, 95% CI= 11.87-35.64, P〈0.01）. Conclusion EC-SOD （C/G）, ALDH2 variant genotypes and drinking might be the risk factors of pancreatic cancer.展开更多
When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses....When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses.Even test samples without any pretreatment can be used as template.This feature suggests that LAMP is superior to PCR in developing point-of-care test strategies.In this study,using Stx1 gene from E.coli as model,we verified that viable cells,dead cells and extracellular DNA could function as template in the LAMP assay.In the incubation at 63℃,viable bacteria in the LAMP reaction mixture lysed completely within 2 min,providing DNA template for nucleic acid amplification.The Stx1 gene in diluted culture medium,spiked tap water,spiked seawater and real seawater all could be detected,with or without the step of DNA extraction.We found that the complex substances in real sample(e.g.natural seawater)exhibited considerable inhibitory effect on the sensitivity of the LAMP assay.These outcomes are meaningful for building a point-of-care strategy by employing the LAMP assay for environmental monitoring,bio-resource surveys,food safety,etc.in particular those based on environmental DNA.展开更多
Objective To investigate whether extracellular signal-regulated kinase (ERK1/2) was involved in changes of vascular smooth muscle cell (VSMC) under hypertension.Methods Two-kidney one clip Wistar hypertensive rats (WH...Objective To investigate whether extracellular signal-regulated kinase (ERK1/2) was involved in changes of vascular smooth muscle cell (VSMC) under hypertension.Methods Two-kidney one clip Wistar hypertensive rats (WHR) were sacrificed and their right kidneys were harvested 4 weeks after surgery.The spontaneously hypertensive rats (SHR) were divided into 4, 8, and 16 weeks old groups (SHR4w, SHR8w, and SHR16w), respectively.The control group were sham operated age-matched Wistar rats.Immunohistochemical technique and Western blotting were applied to study ERK1/2 protein expression in VSMC of the renal vascular trees in WHR, SHR, and control rats.Results Blood pressure in two-kidney one clip WHR obviously increased at one week after surgery, and reached to 198.00±33.00 mm Hg at the end of experiment, significantly higher than that in the control rats (P<0.01).Blood pressure in SHR4w (108.00±11.25 mm Hg) was similar to that in the controls.However, it rose to 122.25±21.75 mm Hg in SHR8w, and even up to 201.75±18.00 mm Hg in SHR16w, which were significantly higher than that of both the SHR4w and the controls (P<0.01).The rate and degree of glomerular fibrosis in WHR were significantly higher than controls (P<0.05).Hyaline degeneration of the afferent arterioles was found in WHR.In contrast, either fibrosis of glomerulus or hyaline degeneration of the arterioles or protein casts was not observed in SHR4w, SHR8w, and SHR16w.Immunohistochemical staining results showed expression of ERK1 was similar to that of ERK2.The positive rates of ERK2 staining in VSMC of afferent arterioles, interlobular, interlobar, and arcuate arteries in two-kidney one clip WHR were significantly higher (7.09%±1.75%, 14.57%±4.58%, 29.44%±7.35%, and 13.63%±3.85%, respectively) than that of the controls(P<0.01).The positive rates of ERK2 staining in VSMC at afferent arterioles, interlobular, interlobar, and arcuate arteries in SHR16w were significantly higher (12.09%±1.40%, 24.17%±6.92%, 32.44%±4.05%, and 18.61%±3.35%, respectively) than that of the controls (P<0.01), too.The expression of ERK1/2 protein of kidney in WHR and SHR16w was significantly higher than that in the controls by Western blotting assay (P<0.01).Conclusion Extracellular signal transduction system are highly expressed in kidney VSMC of two-kidney one clip WHR and SHR.Phospho-ERK1/2 may play an important role in VSMC hypertrophy and hyperplasia under hypertension.展开更多
A strain secreting a strongly acidic polysaccharide flocculating agent was isolated from activated sludge, and identified as Bacillus brevis. The bioflocculant was produced by RL-2 during the late logarithmic growth i...A strain secreting a strongly acidic polysaccharide flocculating agent was isolated from activated sludge, and identified as Bacillus brevis. The bioflocculant was produced by RL-2 during the late logarithmic growth in the batch culture and was recovered from supernatant by ethanol precipitation. The bioflocculant is thermo-stable as its activity remains stable after heated at 100 °C for 45 min. Its flocculating activity with kaolin suspensions was stimulated by the addition of Ca2+, Al3+ and Cu2+. The flocculant consists of glucose, mannose, and galacturonic acid. Its average molecular mass was estimated to be approximately 2.86×105 by the method of viscosity. The flocculant aggregates various inorganic and organic compounds in solution.展开更多
Acute lung injury(ALI)and acute respiratory distress syndrome(ARDS)are common life-threatening lung diseases associated with acute and severe inflammation.Both have high mortality rates,and despite decades of research...Acute lung injury(ALI)and acute respiratory distress syndrome(ARDS)are common life-threatening lung diseases associated with acute and severe inflammation.Both have high mortality rates,and despite decades of research on clinical ALI/ARDS,there are no effective therapeutic strategies.Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury.Recently,studies on the role of extracellular vesicles(EVs)in regulating normal and pathophysiologic cell activities,including inflammation and injury responses,have attracted attention.Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes,which can be used to diagnose and predict the development of ALI/ARDS.EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function,and thereby promote cell proliferation and tissue regeneration.This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation,particularly ALI/ARDS.展开更多
Objective: To study the kinetics and distribution of smooth muscle cell (SMC) proliferation, phe-notypic modulation, and various extracellular matrix (ECM) components accumulation during vein graft remodeling. Methods...Objective: To study the kinetics and distribution of smooth muscle cell (SMC) proliferation, phe-notypic modulation, and various extracellular matrix (ECM) components accumulation during vein graft remodeling. Methods: Normal vein and vein graft in carotid arteries were examined on d 4, d 7, d 14, d 60 and d180 after bypass grafting with immunohistochemical markers of cellular proliferation (proliferating cell nuclear antigen, PCNA), cytoskeletal protein production (a-actin SMC), myosin heavy chain (MHO iso-forms, ECM proteins, and histochemistry (hematoxylin eosin and Elastica-van Gieson stain). Results: Normal veins demonstrated an extremely low level of cellular proliferation and expressed as adult phenotype SM-Cs in media. After bypass grafting, medial SMCs in the graft appeared to be damaged and began to proliferate on d 4, and subsequently migrated and formed the neointima on d 7. Thereafter, the neointima thickened throughout the 180-day period of the experiment, although the neointimal SMC proliferation decreased after d 14. Meanwhile SMCs underwent a distinct phenotypic change from normal adult type to embryonic type. On d 60, embryonic phenotype SMCs began to return to the adult phenotype, but remain to be present in the neointima for as long as 180 d. ECM components including type I collagen, heparin sulfate proteoglucan (HSPG), and dermatan sulfate proteoglcan (decorin) were detected within the neointima on d 7. Thereafter, the accumulation of ECM increased progressively with time. On d 180, a large amount of ECM components were found in the neointima. HSPG mainly accumulated in the superficial and cellular region of the neointima , decorin, on other hand, located in hypocellular area deep in neointima. Type I collagen scatted in both regions. The elastic fibers became rich and arranged continuously in the neointima. Conclusion: The neointima of vein graft was initially formed by proliferation of the embryonic-type SMCs and then thickened infinitely due to ECM accumulation. Prolonged existence of the embryonic-type SMCs in the neointima may contribute to ECM accumulation and increase in the neointima thickness infinitely, which may predispose accelerated stenosis in the vein graft.展开更多
Background:Kirsten rat sarcoma(KRAS)and mutant KRAS^(G12D)have been implicated in human cancers,but it remains unclear whether their activation requires ubiquitination.This study aimed to investigate whether and how F...Background:Kirsten rat sarcoma(KRAS)and mutant KRAS^(G12D)have been implicated in human cancers,but it remains unclear whether their activation requires ubiquitination.This study aimed to investigate whether and how F-box and leucine-rich repeat 6(FBXL6)regulates KRAS and KRAS^(G12D)activity in hepatocellular carcinoma(HCC).Methods:We constructed transgenic mouse strains LC(LSL-Fbxl6^(KI/+);Alb-Cre,n=13),KC(LSL-Kras^(G12D/+);Alb-Cre,n=10)and KLC(LSL-Kras^(G12D/+);LSL-Fbxl6^(KI/+);Alb-Cre,n=12)mice,and then monitored HCC for 320 d.Multiomics approaches and pharmacological inhibitors were used to determine oncogenic signaling in the context of elevated FBXL6 and KRAS activation.Co-immunoprecipitation(Co-IP),Western blotting,ubiquitination assay,and RAS activity detection assay were employed to investigate the underlying molecular mechanism by which FBXL6 activates KRAS.The pathological relevance of the FBXL6/KRAS/extracellular signal-regulated kinase(ERK)/mammalian target of rapamycin(mTOR)/proteins of relevant evolutionary and lymphoid interest domain 2(PRELID2)axis was evaluated in 129 paired samples from HCC patients.Results:FBXL6 is highly expressed in HCC as well as other human cancers(P<0.001).Interestingly,FBXL6 drives HCC in transgenic mice.Mechanistically,elevated FBXL6 promotes the polyubiquitination of both wild-type KRAS and KRAS^(G12D)at lysine 128,leading to the activation of both KRAS and KRAS^(G12D)and promoting their binding to the serine/threonine-protein kinase RAF,which is followed by the activation of mitogen-activated protein kinase kinase(MEK)/ERK/mTOR signaling.The oncogenic activity of the MEK/ERK/mTOR axis relies on PRELID2,which induces reactive oxygen species(ROS)generation.Furthermore,hepatic FBXL6 upregulation facilitates KRAS^(G12D)to induce more severe hepatocarcinogenesis and lung metastasis via the MEK/ERK/mTOR/PRELID2/ROS axis.Dual inhibition of MEK and mTOR effectively suppresses tumor growth and metastasis in this subtype of cancer in vivo.In clinical samples,FBXL6 expression positively correlates with p-ERK(χ^(2)=85.067,P<0.001),p-mTOR(χ^(2)=66.919,P<0.001)and PRELID2(χ^(2)=20.891,P<0.001).The Kaplan-Meier survival analyses suggested that HCC patients with high FBXL6/p-ERK levels predicted worse overall survival(log-rank P<0.001).Conclusions:FBXL6 activates KRAS or KRAS^(G12D)via ubiquitination at the site K128,leading to activation of the ERK/mTOR/PRELID2/ROS axis and tumorigenesis.Dual inhibition of MEK and mTOR effectively protects against FBXL6-and KRAS^(G12D)-induced tumorigenesis,providing a potential therapeutic strategy to treat this aggressive subtype of liver cancer.展开更多
A white rot fungus strain, Trichoderma sp.AH, was isolated from rotten wood in Fushun and used to study the mechanism of lignite bio-solubilization.The results showed that nitric acid pretreated Fushun lignite was sol...A white rot fungus strain, Trichoderma sp.AH, was isolated from rotten wood in Fushun and used to study the mechanism of lignite bio-solubilization.The results showed that nitric acid pretreated Fushun lignite was solubilized by T.sp.AH and that extracellular proteins from T.sp.AH were correlated with the lignite bio-solubilization results.In the presence of Fushun lignite the extracellular protein concentration from T.sp.AH was 4.5 g/L while the concentration was 3 g/L in the absence of Fushun lignite.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) of the extracellular proteins detected at least four new protein bands after the T.sp.AH had solubilized the lignite.Enzyme color reactions showed that extracellular proteins from T.sp.AH mainly consisted of phenol-oxidases, but that lignin decomposition enzymes such as laccase, peroxidase and manganese peroxidases were not present.展开更多
Objective To investigate the role of extracellular regulated kinase (ERK1/2) pathway in cisplatin-induced apoptosis in human ovarian carcinoma cells. Methods Cisplatin-induced apoptosis were stained with DAPI and was ...Objective To investigate the role of extracellular regulated kinase (ERK1/2) pathway in cisplatin-induced apoptosis in human ovarian carcinoma cells. Methods Cisplatin-induced apoptosis were stained with DAPI and was assessed microscopically in human epithelial adenocarcinoma ovarian cell line SKOV3 cells. ERK activation was determined by Western blotting using an anti-phospho-ERK antibody to detect ERK activity. The effect of PD98059 on ERK activity induced by cisplatin was detected by MTT assay. Results Marked apoptosis of SKOV3 cells resulted from 48 hours treatment with 20 μg/mL cisplatin. Strong activation of ERK was led to by 15 μg/mL cisplatin. Dose response and time course of cisplatin induced apoptosis in SKOV3 cells. Cisplatin-induced ERK activation occurred at 12 hours and increased to highest induction at 24 hours by Western blotting. The effect of PD 98059 on ERK activity induced by cisplatin at the concentration of 100 μmol/L PD 98059. Statistically significant decreased in cell survival were observed with 100 μmol/L PD 98059 at 15 and 20 μg/mL cisplatin (P< 0.05). Conclusions Cisplatin activates the ERK signaling pathway in ovarian cancer cell line SKOV3. Inhibition of ERK acti-vity enhances sensitivity to cisplatin cytotoxity in ovarian cancer cell line SKOV3. Evaluation of ERK activity could be useful in predicting which ovarian cancer will response most favorably to cisplatin therapy.展开更多
基金supported by the National Key Research and Development Project Intergovernmental Cooperation in Science and Technology of China(2018YFE0126900)the Key R&D Program of Lishui City(2021ZDYF12)the National Natural Science Foundation of China(82271629)。
文摘Skin wounds are characterized by injury to the skin due to trauma,tearing,cuts,or contusions.As such injuries are common to all human groups,they may at times represent a serious socioeconomic burden.Currently,increasing numbers of studies have focused on the role of mesenchymal stem cell(MSC)-derived extracellular vesicles(EVs)in skin wound repair.As a cell-free therapy,MSC-derived EVs have shown significant application potential in the field of wound repair as a more stable and safer option than conventional cell therapy.Treatment based on MSC-derived EVs can significantly promote the repair of damaged substructures,including the regeneration of vessels,nerves,and hair follicles.In addition,MSC-derived EVs can inhibit scar formation by affecting angiogenesis-related and antifibrotic pathways in promoting macrophage polarization,wound angiogenesis,cell proliferation,and cell migration,and by inhibiting excessive extracellular matrix production.Additionally,these structures can serve as a scaffold for components used in wound repair,and they can be developed into bioengineered EVs to support trauma repair.Through the formulation of standardized culture,isolation,purification,and drug delivery strategies,exploration of the detailed mechanism of EVs will allow them to be used as clinical treatments for wound repair.In conclusion,MSCderived EV-based therapies have important application prospects in wound repair.Here we provide a comprehensive overview of their current status,application potential,and associated drawbacks.
基金supported by the Natural Science Foundationof China (81701872)Medical Innovation Teams of JiangsuProvince (CXTDA2017007).
文摘BACKGROUND: Small extracellular vesicles (sEVs) from bone marrow mesenchymal stemcells (BMSCs) have shown therapeutic potential for cerebral ischemic diseases. However, themechanisms by which BMSC-derived sEVs (BMSC-sEVs) protect neurons against cerebral ischemia/reperfusion (I/R) injury remain unclear. In this study, we explored the neuroprotective effects ofBMSC-sEVs in the primary culture of rat cortical neurons exposed to oxygen-glucose deprivation andreperfusion (OGD/R) injury.METHODS: The primary cortical neuron OGD/R model was established to simulate the processof cerebral I/R in vitro. Based on this model, we examined whether the mechanism through whichBMSC-sEVs could rescue OGD/R-induced neuronal injury.RESULTS: BMSC-sEVs (20 μg/mL, 40 μg/mL) significantly decreased the reactive oxygenspecies (ROS) productions, and increased the activities of superoxide dismutase (SOD) and glutathioneperoxidase (GPx). Additionally, BMSC-sEVs prevented OGD/R-induced neuronal apoptosis in vivo, asindicated by increased cell viability, reduced lactate dehydrogenase (LDH) leakage, decreased terminaldeoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining-positivecells, down-regulated cleaved caspase-3, and up-regulated Bcl-2/Bax ratio. Furthermore, Westernblot and flow cytometry analysis indicated that BMSC-sEV treatment decreased the expression ofphosphorylated calcium/calmodulin-dependent kinase II (p-CaMK II)/CaMK II, suppressed the increaseof intracellular calcium concentration ([Ca2+]i) caused by OGD/R in neurons.CONCLUSIONS: These results demonstrate that BMSC-sEVs have signifi cant neuroprotectiveeff ects against OGD/R-induced cell injury by suppressing oxidative stress and apoptosis, and Ca2+/CaMK II signaling pathways may be involved in this process.
文摘Extract of oven dried leaves of Pongamia pinnata(L) Pierre was used for the synthesis of silver nanoparticles. Stable and crystalline silver nanoparticles were formed by the treatment of aqueous solution of AgNO_3(1m M) with dried leaf extract of Pongamia pinnata(L) Pierre. UV-visible spectroscopy studies were carried out to quantify the formation of silver nanoparticles. Transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the silver nanoparticles. TEM image divulges that silver nanoparticles are quite polydispersed, the size ranging from 20 nm to 50 nm with an average of 38 nm. Water soluble heterocyclic compounds such as flavones were mainly responsible for the reduction and stabilization of the nanoparticles. Silver nanoparticles were effective against Escherichia coli(ATCC 8739), Staphylococcus aureus(ATCC 6538p), Pseudomonas aeruginosa(ATCC 9027) and Klebsiella pneumoniae(clinical isolate). The move towards extracellular synthesis using dried biomass appears to be cost effective, eco-friendly to the conventional methods of nanoparticles synthesis.
基金funded by grants from the EPSRC(EP/M006204/1)the Michael J Fox Foundation+2 种基金the Selfridges Group Foundationthe NIHR Oxford Biomedical Research Centre to G.K.T and J.J.Dsupport from the John Fell Fund(HMD00470).
文摘Extracellular vesicles(EVs)are cell-derived membranous particles that play a crucial role in molecular trafficking,intercellular transport and the egress of unwanted proteins.They have been implicated in many diseases including cancer and neurodegeneration.EVs are detected in all bodily fluids,and their protein and nucleic acid content offers a means of assessing the status of the cells from which they originated.As such,they provide opportunities in biomarker discovery for diagnosis,prognosis or the stratification of diseases as well as an objective monitoring of therapies.The simultaneous assaying of multiple EV-derived markers will be required for an impactful practical application,and multiplexing platforms have evolved with the potential to achieve this.Herein,we provide a comprehensive overview of the currently available multiplexing platforms for EV analysis,with a primary focus on miniaturized and integrated devices that offer potential step changes in analytical power,throughput and consistency.
基金Supported by National Natural Science Foundation of China (30421003,30828004)
文摘Objective To investigate the molecular mechanism of nectin-like molecule 1(NECL1) inhibiting the migration and invasion of U251 glioma cells.Methods We infected U251 glioma cells with adeno-nectin-like molecule 1(Ad-NECL1) or empty adenovirus(Ad).Transwell and wound healing assays were performed to observe the migration of U251 cells incubated with the cell supernatant from Ad-NECL1 or Ad infected U251 cells.DNA microarray was applied to screen the gene expression profile after the restoration of NECL1 in U251 glioma cell lines.The differential expression of osteopontin(OPN),a gene related to migration and invasion,was further analyzed with semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR),Western blot,and immunohistochemistry.Results The restoration of NECL1 inhibited migration of U251 cells significantly(P<0.05).Altogether 195 genes were found differentially expressed by microarray,in which 175 were up-regulated and 20 down-regulated,including 9 extracellular matrix proteins involved in the migration of cells.Both mRNA and protein expressions of OPN,the most markedly reduced extracellular matrix protein,were found decreased in U251 cells after restoration of NECL1.Immunohistochemical assay also detected an increase of OPN in glioma tissues,related with the progressing of malignant grade.Conclusion A link might exist between NECL1 and the extracellular matrix protein OPN in inhibiting the migration and invasion of U251 glioma cells.
基金the National Natural Science Foundation of China (Grant No. 30271067)Fok Ying Tung Education Foundation (71030)+1 种基金 Key Teachers Foundation of the Educational Ministry of China and the State Key Basic Research and Development Plan of China (G199901600
文摘Populus euphratica Olive is the only tree species that can grow in the saline land and also survive cold winters in northwest China, and it plays a very important role in stabilizing the vulnerable ecosystem there. A cell suspension culture was initiated from callus derived from plantlets of Populus euphratica. Cold acclimation was induced (LT50 of 17.5 ℃) in cell suspension at 45 ℃ in the dark for 30 days and the freezing tolerance increased from LT50 of 12.5 ℃ in nonacclimated cells to LT50 of 17.5 ℃ in cold-acclimated cells. Microvacuolation, cytoplasmic augmentation and accumulation of starch granules were observed in cells that were cold-acclimated by exposure to low temperatures. Several qualitative and quantitative changes in proteins were noted during cold acclimation. Antibodies to carrot extracellular (apoplastic) 36 kD antifreeze protein did not cross react on immunoelectroblots with extracellular proteins in cell suspension culture medium of Populus euphratica, indicating no common epitopes in the carrot 36 kD antifreeze protein and P. euphratica extracellular proteins. The relationship of these changes to cold acclimation in Populus euphratica cell cultures was discussed.
文摘Cardiovascular aging is a physiological process gradually leading to structural degeneration and functional loss of all the cardiac and vascular components. Conduction system is also deeply influenced by the aging process with relevant reflexes in the clinical side. Age-related arrhythmias carry significant morbidity and mortality and represent a clinical and economical burden. An important and unjustly unrecognized actor in the pathophysiology of aging is represented by the extracellular matrix （ECM） that not only structurally supports the heart determining its mechanical and functional properties, but also sends a biological signaling regulating cellular function and maintaining tissue homeostasis. At the biophysical level, cardiac ECM exhibits a peculiar degree of anisotropy, which is among the main determinants of the conductive properties of the specialized electrical conduction system. Age-associated alterations of cardiac ECM are therefore able to profoundly affect the function of the conduction system with striking impact on the patient clinical conditions. This review will focus on the ECM changes that occur during aging in the heart conduction system and on their translation to the clinical scenario. Potential diagnostic and therapeutical perspectives arising from the knowledge on ECM age-associated alterations are further discussed.
文摘Objective：Hyperglycemia stimulates secretion of transforming growth factor-βl （TGF-βl） in cultured glomerular mesangial cells, thereby increases production of extracellular matrix （ECM）. We examined the effect of antisense mRNA for Smad2 on high glucose-induced ECM production in rat mesangial cells. Methods..A mammalian expression vector, pES2a, which expresses antisense Smad2 mRNA and green fluorescent protein （EGFP）, was transfected into mesangial cells. Following incubation in high glucose medium, EGFP expression and Smad2 mRNA level were determined by fluorescence microscopy and PCR, respectively. Secreted fibronectin and type IV collagen were assessed by enzyme-linked immunosorbent assay. Results ：Within 48 h of incubation in high glucose medium, Smad2 mRNA level significantly increased by 1.6 fold in association with increases in prodtaction of both fibronectin （from [45.86±2.73] to [84.19±6.81] ng/ml） and type IV collagen （from [16. 28±0. 90] to [55.27±4.75] ng/ml） in nontransfected cells （P〈0.05）. In pES2a-transfected cells, the high glucose-induced increase in Smad2 mRNA was abrogated completely, in parallel with significant suppression of the high glucose-indtmed increase in fibronectinproduction （[54.44±4.99] ng/ml） and type Ⅳ collagen （[20.96±2.47] ng/ml）. An empty vector was without effects. Coneluslon：These findings demonstrate that Smad2 plays a critical role in mediating high glucose-stimulated ECM production in mesangial cells, indicating that inhibition of Smad2 activity by antisense Smad2 mRNA may be an effective means to attenuate glomerular matrix accumulation in diabetic nephropathy.
文摘Extracellular RNAs(exRNAs) are novel circulating factors that can be used as biomarkers in various diseases. Their unique and diverse kinds, as well as their role as biomarkers, make them significant biomarkers. There has been immense work carried out since the discovery of exRNAs in circulation and other biological fluids to catalog and determine whether exRNAs may be utilized as indicators for health and illness. In this review, we aim to understand the current state of exRNAs in relation to various diseases and their potential as biomarkers. We will also review current issues and challenges faced in using exRNAs, with clinical and lab trials, that can be used as viable markers for different diseases.
基金supported by the National Natural Science Foundation of China (No.31670496)。
文摘Changbai Mountain,central in the distribution of Pinus koraiensis,supports a virgin Korean pine forest with vertical gradient distribution.Soil extracellular enzyme activity(EEA) and enzyme stoichiometry(ES) are reliable indicators of the energy and nutrients utilized by microbial communities and of soil nutrient changes.We measured four representative soil EEAs(sucrase,cellulase,urease,acid phosphatase) at two soil layers(A:0-5 cm and B:5-10 cm)beneath Korean pine forest at five elevations on Changbai Mountain during growing season.The vertical and seasonal variations of EEAs were analyzed by soil enzyme stoichiometry to quantify the role of soil microorganism in the nutrient cycling process.The activities of four soil extracellular enzymes and the ratios of enzyme activity to soil microbial biomass carbon(EA/SMBC) did not vary with elevation.The first partition point of multiple regression trees was in September,and the second branch was split by elevation.Seasonal change had more influence on soil enzyme activity(A layer:75.6%;B layer:71.3%) than did change in elevation(A layer:7.8%;B layer:7.5%).Over one entire growing season,both vector length and vector angle were unchanged by elevation,but varied significantly by month.Among the soil physicochemical factors,available phosphorus and pH were the main factors affecting the four soil EE As.The ratio of basal area of the coniferous tree to broad-leaved tree species(S_(con)/S_(br)),soil microbial biomass carbon(MBC) and nitrogen(MBN) influenced the four soil EE As.The results of vector analysis revealed that C and N sources were generally sufficient,but P was limiting(vector angle> 45°).The vector angle for September was significantly higher than for other months.This result verified that phosphorus was the limiting factor affecting soil microorganism function in nutrient metabolism and cycling.Soil enzyme stoichiometry proved to be an efficient index for quantifying soil microorganismmediated nutrient cycling in the Korean pine ecosystem.
文摘Objective To investigate the correlation between drinking behavior combined with polymorphisms of extracellular superoxide dismutase （EC-SOD） and aldehyde dehydrogenase-2 （ALDH2） genes and pancreatic cancer. Methods The genetic polymorphisms of EC-SOD and ALDH2 were analyzed by polymerase chain reaction restriction fragment length polymorphism in the peripheral blood leukocytes obtained from 680 pancreatic cancer cases and 680 non-cancer controls. Subsequently the frequency of genotype was compared between the pancreatic cancer patients and the healthy controls.The relationship of drinking with pancreatic cancer was analyzed. Results The frequencies of EC-SOD （C/G） and ALDH2 variant genotypes were 37.35% and 68.82% respectively in the pancreatic cancer cases, and were significantly higher than those in the healthy controls （21.03% and 44.56%, all P〈0.01）. People who carried EC-SOD （C/G） （0R=2.24, 95% C1= 1.81-4.03, P〈0.01） or ALDH2 variant genotypes （OR=2.75, 95% CI=1.92-4.47, P〈0.01） had a high risk to develop pancreatic cancer. Those who carried EC-SOD （C/G） genotype combined with ALDH2 variant genotype had a high risk for pancreatic cancer （29.56% vs. 6.76%, 0R=7.69, 95% CI=3.58-10.51, P〈0.01）. The drinking rate of the pancreatic cancer group （64.12%） was significantly higher than that of the control group （40.15%; OR=2.66, 95% CI=1.30-4.42, P〈0.01）. An interaction between drinking and EC-SOD （C/G）/ALDH2 variant genotypes increased the risk of occurrence of pancreatic cancer （OR=25.00, 95% CI= 11.87-35.64, P〈0.01）. Conclusion EC-SOD （C/G）, ALDH2 variant genotypes and drinking might be the risk factors of pancreatic cancer.
文摘When the loop-mediated isothermal amplification(LAMP)assay is used for detecting target genes,DNA extraction is unnecessary in many cases.Simple pretreatment(e.g.heating)is enough to obtain rather sensitive responses.Even test samples without any pretreatment can be used as template.This feature suggests that LAMP is superior to PCR in developing point-of-care test strategies.In this study,using Stx1 gene from E.coli as model,we verified that viable cells,dead cells and extracellular DNA could function as template in the LAMP assay.In the incubation at 63℃,viable bacteria in the LAMP reaction mixture lysed completely within 2 min,providing DNA template for nucleic acid amplification.The Stx1 gene in diluted culture medium,spiked tap water,spiked seawater and real seawater all could be detected,with or without the step of DNA extraction.We found that the complex substances in real sample(e.g.natural seawater)exhibited considerable inhibitory effect on the sensitivity of the LAMP assay.These outcomes are meaningful for building a point-of-care strategy by employing the LAMP assay for environmental monitoring,bio-resource surveys,food safety,etc.in particular those based on environmental DNA.
文摘Objective To investigate whether extracellular signal-regulated kinase (ERK1/2) was involved in changes of vascular smooth muscle cell (VSMC) under hypertension.Methods Two-kidney one clip Wistar hypertensive rats (WHR) were sacrificed and their right kidneys were harvested 4 weeks after surgery.The spontaneously hypertensive rats (SHR) were divided into 4, 8, and 16 weeks old groups (SHR4w, SHR8w, and SHR16w), respectively.The control group were sham operated age-matched Wistar rats.Immunohistochemical technique and Western blotting were applied to study ERK1/2 protein expression in VSMC of the renal vascular trees in WHR, SHR, and control rats.Results Blood pressure in two-kidney one clip WHR obviously increased at one week after surgery, and reached to 198.00±33.00 mm Hg at the end of experiment, significantly higher than that in the control rats (P<0.01).Blood pressure in SHR4w (108.00±11.25 mm Hg) was similar to that in the controls.However, it rose to 122.25±21.75 mm Hg in SHR8w, and even up to 201.75±18.00 mm Hg in SHR16w, which were significantly higher than that of both the SHR4w and the controls (P<0.01).The rate and degree of glomerular fibrosis in WHR were significantly higher than controls (P<0.05).Hyaline degeneration of the afferent arterioles was found in WHR.In contrast, either fibrosis of glomerulus or hyaline degeneration of the arterioles or protein casts was not observed in SHR4w, SHR8w, and SHR16w.Immunohistochemical staining results showed expression of ERK1 was similar to that of ERK2.The positive rates of ERK2 staining in VSMC of afferent arterioles, interlobular, interlobar, and arcuate arteries in two-kidney one clip WHR were significantly higher (7.09%±1.75%, 14.57%±4.58%, 29.44%±7.35%, and 13.63%±3.85%, respectively) than that of the controls(P<0.01).The positive rates of ERK2 staining in VSMC at afferent arterioles, interlobular, interlobar, and arcuate arteries in SHR16w were significantly higher (12.09%±1.40%, 24.17%±6.92%, 32.44%±4.05%, and 18.61%±3.35%, respectively) than that of the controls (P<0.01), too.The expression of ERK1/2 protein of kidney in WHR and SHR16w was significantly higher than that in the controls by Western blotting assay (P<0.01).Conclusion Extracellular signal transduction system are highly expressed in kidney VSMC of two-kidney one clip WHR and SHR.Phospho-ERK1/2 may play an important role in VSMC hypertrophy and hyperplasia under hypertension.
文摘A strain secreting a strongly acidic polysaccharide flocculating agent was isolated from activated sludge, and identified as Bacillus brevis. The bioflocculant was produced by RL-2 during the late logarithmic growth in the batch culture and was recovered from supernatant by ethanol precipitation. The bioflocculant is thermo-stable as its activity remains stable after heated at 100 °C for 45 min. Its flocculating activity with kaolin suspensions was stimulated by the addition of Ca2+, Al3+ and Cu2+. The flocculant consists of glucose, mannose, and galacturonic acid. Its average molecular mass was estimated to be approximately 2.86×105 by the method of viscosity. The flocculant aggregates various inorganic and organic compounds in solution.
基金This work was supported by the Weatherhead Endowment Fund
文摘Acute lung injury(ALI)and acute respiratory distress syndrome(ARDS)are common life-threatening lung diseases associated with acute and severe inflammation.Both have high mortality rates,and despite decades of research on clinical ALI/ARDS,there are no effective therapeutic strategies.Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury.Recently,studies on the role of extracellular vesicles(EVs)in regulating normal and pathophysiologic cell activities,including inflammation and injury responses,have attracted attention.Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes,which can be used to diagnose and predict the development of ALI/ARDS.EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function,and thereby promote cell proliferation and tissue regeneration.This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation,particularly ALI/ARDS.
文摘Objective: To study the kinetics and distribution of smooth muscle cell (SMC) proliferation, phe-notypic modulation, and various extracellular matrix (ECM) components accumulation during vein graft remodeling. Methods: Normal vein and vein graft in carotid arteries were examined on d 4, d 7, d 14, d 60 and d180 after bypass grafting with immunohistochemical markers of cellular proliferation (proliferating cell nuclear antigen, PCNA), cytoskeletal protein production (a-actin SMC), myosin heavy chain (MHO iso-forms, ECM proteins, and histochemistry (hematoxylin eosin and Elastica-van Gieson stain). Results: Normal veins demonstrated an extremely low level of cellular proliferation and expressed as adult phenotype SM-Cs in media. After bypass grafting, medial SMCs in the graft appeared to be damaged and began to proliferate on d 4, and subsequently migrated and formed the neointima on d 7. Thereafter, the neointima thickened throughout the 180-day period of the experiment, although the neointimal SMC proliferation decreased after d 14. Meanwhile SMCs underwent a distinct phenotypic change from normal adult type to embryonic type. On d 60, embryonic phenotype SMCs began to return to the adult phenotype, but remain to be present in the neointima for as long as 180 d. ECM components including type I collagen, heparin sulfate proteoglucan (HSPG), and dermatan sulfate proteoglcan (decorin) were detected within the neointima on d 7. Thereafter, the accumulation of ECM increased progressively with time. On d 180, a large amount of ECM components were found in the neointima. HSPG mainly accumulated in the superficial and cellular region of the neointima , decorin, on other hand, located in hypocellular area deep in neointima. Type I collagen scatted in both regions. The elastic fibers became rich and arranged continuously in the neointima. Conclusion: The neointima of vein graft was initially formed by proliferation of the embryonic-type SMCs and then thickened infinitely due to ECM accumulation. Prolonged existence of the embryonic-type SMCs in the neointima may contribute to ECM accumulation and increase in the neointima thickness infinitely, which may predispose accelerated stenosis in the vein graft.
基金supported by the National Natural Science Foundation of China(82370631)the Talent Foundations from Army Medical University(4174C6),the Chongqing Government(CQYC20220303727)to Xie CMthe National Natural Science Foundation of China(31900449)to Xiong HJ.
文摘Background:Kirsten rat sarcoma(KRAS)and mutant KRAS^(G12D)have been implicated in human cancers,but it remains unclear whether their activation requires ubiquitination.This study aimed to investigate whether and how F-box and leucine-rich repeat 6(FBXL6)regulates KRAS and KRAS^(G12D)activity in hepatocellular carcinoma(HCC).Methods:We constructed transgenic mouse strains LC(LSL-Fbxl6^(KI/+);Alb-Cre,n=13),KC(LSL-Kras^(G12D/+);Alb-Cre,n=10)and KLC(LSL-Kras^(G12D/+);LSL-Fbxl6^(KI/+);Alb-Cre,n=12)mice,and then monitored HCC for 320 d.Multiomics approaches and pharmacological inhibitors were used to determine oncogenic signaling in the context of elevated FBXL6 and KRAS activation.Co-immunoprecipitation(Co-IP),Western blotting,ubiquitination assay,and RAS activity detection assay were employed to investigate the underlying molecular mechanism by which FBXL6 activates KRAS.The pathological relevance of the FBXL6/KRAS/extracellular signal-regulated kinase(ERK)/mammalian target of rapamycin(mTOR)/proteins of relevant evolutionary and lymphoid interest domain 2(PRELID2)axis was evaluated in 129 paired samples from HCC patients.Results:FBXL6 is highly expressed in HCC as well as other human cancers(P<0.001).Interestingly,FBXL6 drives HCC in transgenic mice.Mechanistically,elevated FBXL6 promotes the polyubiquitination of both wild-type KRAS and KRAS^(G12D)at lysine 128,leading to the activation of both KRAS and KRAS^(G12D)and promoting their binding to the serine/threonine-protein kinase RAF,which is followed by the activation of mitogen-activated protein kinase kinase(MEK)/ERK/mTOR signaling.The oncogenic activity of the MEK/ERK/mTOR axis relies on PRELID2,which induces reactive oxygen species(ROS)generation.Furthermore,hepatic FBXL6 upregulation facilitates KRAS^(G12D)to induce more severe hepatocarcinogenesis and lung metastasis via the MEK/ERK/mTOR/PRELID2/ROS axis.Dual inhibition of MEK and mTOR effectively suppresses tumor growth and metastasis in this subtype of cancer in vivo.In clinical samples,FBXL6 expression positively correlates with p-ERK(χ^(2)=85.067,P<0.001),p-mTOR(χ^(2)=66.919,P<0.001)and PRELID2(χ^(2)=20.891,P<0.001).The Kaplan-Meier survival analyses suggested that HCC patients with high FBXL6/p-ERK levels predicted worse overall survival(log-rank P<0.001).Conclusions:FBXL6 activates KRAS or KRAS^(G12D)via ubiquitination at the site K128,leading to activation of the ERK/mTOR/PRELID2/ROS axis and tumorigenesis.Dual inhibition of MEK and mTOR effectively protects against FBXL6-and KRAS^(G12D)-induced tumorigenesis,providing a potential therapeutic strategy to treat this aggressive subtype of liver cancer.
基金Projects 50874107 and 50374068 supported by the National Natural Science Foundation of ChinaCPEUKF06-12 by the Foundation of Key Laboratory of Coal Processing & Efficient Utilization, Ministry of Education of China
文摘A white rot fungus strain, Trichoderma sp.AH, was isolated from rotten wood in Fushun and used to study the mechanism of lignite bio-solubilization.The results showed that nitric acid pretreated Fushun lignite was solubilized by T.sp.AH and that extracellular proteins from T.sp.AH were correlated with the lignite bio-solubilization results.In the presence of Fushun lignite the extracellular protein concentration from T.sp.AH was 4.5 g/L while the concentration was 3 g/L in the absence of Fushun lignite.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) of the extracellular proteins detected at least four new protein bands after the T.sp.AH had solubilized the lignite.Enzyme color reactions showed that extracellular proteins from T.sp.AH mainly consisted of phenol-oxidases, but that lignin decomposition enzymes such as laccase, peroxidase and manganese peroxidases were not present.
基金Supported by Heilongjiang Province Natural Science Funds (D03-55) and Heilongjiang Province Sanitary Bureau Science Funds (2003-003)
文摘Objective To investigate the role of extracellular regulated kinase (ERK1/2) pathway in cisplatin-induced apoptosis in human ovarian carcinoma cells. Methods Cisplatin-induced apoptosis were stained with DAPI and was assessed microscopically in human epithelial adenocarcinoma ovarian cell line SKOV3 cells. ERK activation was determined by Western blotting using an anti-phospho-ERK antibody to detect ERK activity. The effect of PD98059 on ERK activity induced by cisplatin was detected by MTT assay. Results Marked apoptosis of SKOV3 cells resulted from 48 hours treatment with 20 μg/mL cisplatin. Strong activation of ERK was led to by 15 μg/mL cisplatin. Dose response and time course of cisplatin induced apoptosis in SKOV3 cells. Cisplatin-induced ERK activation occurred at 12 hours and increased to highest induction at 24 hours by Western blotting. The effect of PD 98059 on ERK activity induced by cisplatin at the concentration of 100 μmol/L PD 98059. Statistically significant decreased in cell survival were observed with 100 μmol/L PD 98059 at 15 and 20 μg/mL cisplatin (P< 0.05). Conclusions Cisplatin activates the ERK signaling pathway in ovarian cancer cell line SKOV3. Inhibition of ERK acti-vity enhances sensitivity to cisplatin cytotoxity in ovarian cancer cell line SKOV3. Evaluation of ERK activity could be useful in predicting which ovarian cancer will response most favorably to cisplatin therapy.
