OBJECTIVE Chloroquine is considered as a potential chemotherapy and radiotherapy sensitizer,but the anticancer effect of chloroquine alone is limited.Since we found that the flavonoid kaempferol effectively sensitizes...OBJECTIVE Chloroquine is considered as a potential chemotherapy and radiotherapy sensitizer,but the anticancer effect of chloroquine alone is limited.Since we found that the flavonoid kaempferol effectively sensitizes glioma cells to chloroquine-mediated cell death,we investigated the underlying mechanisms of glioma cell death induced by the combination of kaempferol and chloroquine.METHODS To examine the effect of kaempferol and/or chloroquine on various glioma cells,cell viability assay using calcein-AM and EthD-1was performed.The changes in the lysosomal structures following treatment with kaempferol and/or chloroquine were observed by electron microscopy and fluorescence microscopy using acridine orange or Lyso-tracker Red.The changes in cathepsin D proteins were analyzed by Western blotting,immunocytochemistry,and fluorescence microscopy using BODIPY FL-pepstatin.RESULTS Treatment with subtoxic doses of chloroquine,when combined with kaempferol,effectively induced cell death in various glioma cells,but not in normal astrocytes.While kaempferol treatment increased the numbers of lysosome,chloroquine treatment increased lysosomal masses.Combined treatment with kaempferol and chloroquine induced the expansion and subsequent rupture of lysosomes,leading to the spillage of the lysosomal contents into the cytosol.We found that while kaemfperol treatment increased the active mature forms of cathepsin D,chloroquine treatment completely blocked the processing of cathepsin D.The processing of cathepsin D was also blocked by the combined treatment,but the activity of cathepsin D,which was released from the lysosomes,was restored.The cell death induced by kaempferol and chloroquine in U251 MG cells was accompanied by mitochondrial dysfunction,ER stress,and DNA damage.CONCLUSION Disruption of lysosomal membrane integrity and a resultant release of lysosomal proteases may critically contribute to the irreparable damage of various organelles and glioma cell death by chloroquine plus kaempferol.展开更多
OBJECTIVE Identification of novel autophagy inhibitors for the combinational treatment of non-small cell lung cancer(NSCLC).METHODS MTT assay and annexin V/PI staining assay were used to evaluate the cell proliferatio...OBJECTIVE Identification of novel autophagy inhibitors for the combinational treatment of non-small cell lung cancer(NSCLC).METHODS MTT assay and annexin V/PI staining assay were used to evaluate the cell proliferation and apoptosis,respectively.Immunofluorescence staining and cathepsin activity assay were used to detect autophagy.Small interfering RNA was performed to silence the genes and Western blot assay was used to evaluate the protein express levels.Xenograft experiments were applied for in vivo evaluation.RESULTS Cepharanthine,a natural compound,increased LC3-II expression and GFP-LC3 puncta formation in NSCLC NCI-H1975 cells.Numerous yellow puncta were observed in cepharanthine-treated cells with m RFP-EGFP-LC3 transfection.Co-staining of GFP-LC3 with LysoT racker red or LAMP1 antibody suggested that cepharanthine inhibits autophagosomes-lysosomes fusion.Moreover,cepharanthine attenuated the lysosomal cathepsins maturation.We also confirmed that dacomitinib induced cytoprotective autophagy.Combined treatment with cepharanthine increased the anti-cancer effects of dacomitinib in vitro and in vivo.Besides,cepharanthine could not enhance the anti-cancer effect of dacomitinib in autophagy deficient cells.CONCLUSION Cepharanthine might be further developed as a promising autophagic inhibitor,and combined treatment cepharanthine with dacomitinib could pose as an effective strategy for NSCLC treatment.展开更多
OBJECTIVE The proteasome inhibitor bortezomib(BTZ)is a first-line anti-multi⁃ple myeloma drug.BTZ-induced peripheral neu⁃ropathy(BIPN)is a main adverse effect that char⁃acterized by neuropathic pain.There is still no ...OBJECTIVE The proteasome inhibitor bortezomib(BTZ)is a first-line anti-multi⁃ple myeloma drug.BTZ-induced peripheral neu⁃ropathy(BIPN)is a main adverse effect that char⁃acterized by neuropathic pain.There is still no strategy to prevent or treat BIPN,attributed to the unidentified mechanisms underlying BIPN.Previous studies suggested that BTZ impairs Schwann cells and thus leads to axonal demye⁃lination,whereas it remained not fully understood how BTZ cause Schwann cell death.It was observed that BTZ upregulates the autophagy marker LC3-Ⅱprotein in Schwann cells.However,it remains unclear whether BTZ causes autopha⁃gy-lysosome dysfunction in Schwann cells.METHODS The male C57BL/6 mice were intra⁃venous injection of BTZ(1 mg·kg-1 per day,twice weekly for a total of 4 weeks).The paw withdraw⁃al latency was tested by the Von Frey test and Hargreaves test to reflect the neuropathic pain.The conduction velocity and the action potential amplitude of the tail nerve were tested by neuro⁃physiological assessment to reflect peripheral nerve function.The histomorphology of the sciat⁃ic nerves was detected by immunofluorescence and transmission electron microscopy to reflect the demyelination and axonal degeneration.The RSC96 cells,the Schwann cell-like immortal cells,were cultured and exposed to BTZ.The lysosomal function was determined by Lyso⁃Tracker and DQ-BSA staining.Autophagy-relat⁃ed proteins,including p62 and LC3,and lysosom⁃al hydrolase cathepsin B were determined by Western blotting.RESULTS①BTZ induced mechano-allodynia,neurological conduction abnormalities of the tail nerve,demyelination and axonal degeneration of the sciatic nerves.②BTZ caused lysosomal dysfunction,resulting in the blockade of autophagy flux in Schwann cells and sciatic nerves.③The lysosomal activator Torin1 reversed lysosomal dysfunction caused by BTZ in Schwann cells.④Torin1 improved BTZ-induced mechano-allodynia and demyelination of sciatic nerves.CONCLUSION BTZ led to lyso⁃somal dysfunction in Schwann cells and contrib⁃uted to BIPN.Lysosomal activation could be a promising strategy for BIPN intervention.展开更多
OBJECTIVE Astrocytes activa⁃tion and glial scar formation are the important causes that hinder the recovery of motor function after cerebral ischemia.However,its precise mechanism has not been clarified.Peroxisome pro...OBJECTIVE Astrocytes activa⁃tion and glial scar formation are the important causes that hinder the recovery of motor function after cerebral ischemia.However,its precise mechanism has not been clarified.Peroxisome proliferator-activated receptorα(PPARα)is a ligand-activated nuclear transcriptional factor.This study aims to further clarify the role of PPARαin astrocyte activation after cerebral isch⁃emia and explore the underlying mechanism.METHODS Astrocyte activation in vivo model was induced by transient middle cerebral artery occlusion(tMCAO)in mice and in vitro model was induced by oxygen-glucose deprivation/reox⁃ygenation(OGD/R)in primary culture of mouse astrocyte.The effects of PPARαon astrocyte ac⁃tivation and autophagy flux were observed in the condition of PPARαdysfunction(PPARαnull mice)or PPARαactivation by oleoylethanol⁃amide(OEA).RESULTS PPARαmainly ex⁃pressed in activated astrocytes during the chron⁃ic phase of brain ischemia and PPARαdysfunc⁃tion promoted astrocytes activation after brain ischemia in vivo and in vitro.After cerebral isch⁃emia,the expressions of LC3-Ⅱ/Ⅰand P62 both increased in the brain tissue near the infarct core.Autophagic vesicles accumulation was ob⁃served by electron microscopy in astrocytes,and mRFP-GFP-LC3 adenovirus infection assay indi⁃cated the block of autophagy flux.PPARαdys⁃function aggravated autophagy flux block,while PPARαactivation preserved the lysosome func⁃tion and restored autophagy flux in astrocytes after OGD/R.Autophagy flux blocker bafilomycin A1 and chloroquine antagonized the effect of OEA on inhibiting astrocyte activation.CONCLU⁃SION PPARαactivation inhibites the over-activa⁃tion of astrocytes by restoring the autophagy flux after cerebral ischemia.展开更多
基金The project supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)〔2011-0030043(SRC)〕a grant of the Korean Health Technology R&D Progect,Ministry of Health&Welfare(HI14C2230)
文摘OBJECTIVE Chloroquine is considered as a potential chemotherapy and radiotherapy sensitizer,but the anticancer effect of chloroquine alone is limited.Since we found that the flavonoid kaempferol effectively sensitizes glioma cells to chloroquine-mediated cell death,we investigated the underlying mechanisms of glioma cell death induced by the combination of kaempferol and chloroquine.METHODS To examine the effect of kaempferol and/or chloroquine on various glioma cells,cell viability assay using calcein-AM and EthD-1was performed.The changes in the lysosomal structures following treatment with kaempferol and/or chloroquine were observed by electron microscopy and fluorescence microscopy using acridine orange or Lyso-tracker Red.The changes in cathepsin D proteins were analyzed by Western blotting,immunocytochemistry,and fluorescence microscopy using BODIPY FL-pepstatin.RESULTS Treatment with subtoxic doses of chloroquine,when combined with kaempferol,effectively induced cell death in various glioma cells,but not in normal astrocytes.While kaempferol treatment increased the numbers of lysosome,chloroquine treatment increased lysosomal masses.Combined treatment with kaempferol and chloroquine induced the expansion and subsequent rupture of lysosomes,leading to the spillage of the lysosomal contents into the cytosol.We found that while kaemfperol treatment increased the active mature forms of cathepsin D,chloroquine treatment completely blocked the processing of cathepsin D.The processing of cathepsin D was also blocked by the combined treatment,but the activity of cathepsin D,which was released from the lysosomes,was restored.The cell death induced by kaempferol and chloroquine in U251 MG cells was accompanied by mitochondrial dysfunction,ER stress,and DNA damage.CONCLUSION Disruption of lysosomal membrane integrity and a resultant release of lysosomal proteases may critically contribute to the irreparable damage of various organelles and glioma cell death by chloroquine plus kaempferol.
基金supported by Science and Technology Development Fund,Macao S.A.R(FDCT)(024/2016/A1)Research Fund of University of Macao(MYRG2015-00091-ICMS-QRCM and MYRG2015-00101-ICMS-QRCM)
文摘OBJECTIVE Identification of novel autophagy inhibitors for the combinational treatment of non-small cell lung cancer(NSCLC).METHODS MTT assay and annexin V/PI staining assay were used to evaluate the cell proliferation and apoptosis,respectively.Immunofluorescence staining and cathepsin activity assay were used to detect autophagy.Small interfering RNA was performed to silence the genes and Western blot assay was used to evaluate the protein express levels.Xenograft experiments were applied for in vivo evaluation.RESULTS Cepharanthine,a natural compound,increased LC3-II expression and GFP-LC3 puncta formation in NSCLC NCI-H1975 cells.Numerous yellow puncta were observed in cepharanthine-treated cells with m RFP-EGFP-LC3 transfection.Co-staining of GFP-LC3 with LysoT racker red or LAMP1 antibody suggested that cepharanthine inhibits autophagosomes-lysosomes fusion.Moreover,cepharanthine attenuated the lysosomal cathepsins maturation.We also confirmed that dacomitinib induced cytoprotective autophagy.Combined treatment with cepharanthine increased the anti-cancer effects of dacomitinib in vitro and in vivo.Besides,cepharanthine could not enhance the anti-cancer effect of dacomitinib in autophagy deficient cells.CONCLUSION Cepharanthine might be further developed as a promising autophagic inhibitor,and combined treatment cepharanthine with dacomitinib could pose as an effective strategy for NSCLC treatment.
文摘OBJECTIVE The proteasome inhibitor bortezomib(BTZ)is a first-line anti-multi⁃ple myeloma drug.BTZ-induced peripheral neu⁃ropathy(BIPN)is a main adverse effect that char⁃acterized by neuropathic pain.There is still no strategy to prevent or treat BIPN,attributed to the unidentified mechanisms underlying BIPN.Previous studies suggested that BTZ impairs Schwann cells and thus leads to axonal demye⁃lination,whereas it remained not fully understood how BTZ cause Schwann cell death.It was observed that BTZ upregulates the autophagy marker LC3-Ⅱprotein in Schwann cells.However,it remains unclear whether BTZ causes autopha⁃gy-lysosome dysfunction in Schwann cells.METHODS The male C57BL/6 mice were intra⁃venous injection of BTZ(1 mg·kg-1 per day,twice weekly for a total of 4 weeks).The paw withdraw⁃al latency was tested by the Von Frey test and Hargreaves test to reflect the neuropathic pain.The conduction velocity and the action potential amplitude of the tail nerve were tested by neuro⁃physiological assessment to reflect peripheral nerve function.The histomorphology of the sciat⁃ic nerves was detected by immunofluorescence and transmission electron microscopy to reflect the demyelination and axonal degeneration.The RSC96 cells,the Schwann cell-like immortal cells,were cultured and exposed to BTZ.The lysosomal function was determined by Lyso⁃Tracker and DQ-BSA staining.Autophagy-relat⁃ed proteins,including p62 and LC3,and lysosom⁃al hydrolase cathepsin B were determined by Western blotting.RESULTS①BTZ induced mechano-allodynia,neurological conduction abnormalities of the tail nerve,demyelination and axonal degeneration of the sciatic nerves.②BTZ caused lysosomal dysfunction,resulting in the blockade of autophagy flux in Schwann cells and sciatic nerves.③The lysosomal activator Torin1 reversed lysosomal dysfunction caused by BTZ in Schwann cells.④Torin1 improved BTZ-induced mechano-allodynia and demyelination of sciatic nerves.CONCLUSION BTZ led to lyso⁃somal dysfunction in Schwann cells and contrib⁃uted to BIPN.Lysosomal activation could be a promising strategy for BIPN intervention.
基金National Natural Science Foundation of China(81603093)and the Open Research Fund of State Key Laboratory of Cellu⁃lar Stress Biology,Xiamen University(SKLC⁃SB2019KF016)。
文摘OBJECTIVE Astrocytes activa⁃tion and glial scar formation are the important causes that hinder the recovery of motor function after cerebral ischemia.However,its precise mechanism has not been clarified.Peroxisome proliferator-activated receptorα(PPARα)is a ligand-activated nuclear transcriptional factor.This study aims to further clarify the role of PPARαin astrocyte activation after cerebral isch⁃emia and explore the underlying mechanism.METHODS Astrocyte activation in vivo model was induced by transient middle cerebral artery occlusion(tMCAO)in mice and in vitro model was induced by oxygen-glucose deprivation/reox⁃ygenation(OGD/R)in primary culture of mouse astrocyte.The effects of PPARαon astrocyte ac⁃tivation and autophagy flux were observed in the condition of PPARαdysfunction(PPARαnull mice)or PPARαactivation by oleoylethanol⁃amide(OEA).RESULTS PPARαmainly ex⁃pressed in activated astrocytes during the chron⁃ic phase of brain ischemia and PPARαdysfunc⁃tion promoted astrocytes activation after brain ischemia in vivo and in vitro.After cerebral isch⁃emia,the expressions of LC3-Ⅱ/Ⅰand P62 both increased in the brain tissue near the infarct core.Autophagic vesicles accumulation was ob⁃served by electron microscopy in astrocytes,and mRFP-GFP-LC3 adenovirus infection assay indi⁃cated the block of autophagy flux.PPARαdys⁃function aggravated autophagy flux block,while PPARαactivation preserved the lysosome func⁃tion and restored autophagy flux in astrocytes after OGD/R.Autophagy flux blocker bafilomycin A1 and chloroquine antagonized the effect of OEA on inhibiting astrocyte activation.CONCLU⁃SION PPARαactivation inhibites the over-activa⁃tion of astrocytes by restoring the autophagy flux after cerebral ischemia.
