Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environme...Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environmental toxin that causes Parkinson's disease.However,the mechanism by which Sal mediates dopaminergic neuronal death remains unclear.In this study,we found that Sal significantly enhanced the global level of N~6-methyladenosine(m~6A)RNA methylation in PC12 cells,mainly by inducing the downregulation of the expression of m~6A demethylases fat mass and obesity-associated protein(FTO)and alk B homolog 5(ALKBH5).RNA sequencing analysis showed that Sal downregulated the Hippo signaling pathway.The m~6A reader YTH domain-containing family protein 2(YTHDF2)promoted the degradation of m~6A-containing Yes-associated protein 1(YAP1)mRNA,which is a downstream key effector in the Hippo signaling pathway.Additionally,downregulation of YAP1 promoted autophagy,indicating that the mutual regulation between YAP1 and autophagy can lead to neurotoxicity.These findings reveal the role of Sal on m~6A RNA methylation and suggest that Sal may act as an RNA methylation inducer mediating dopaminergic neuronal death through YAP1 and autophagy.Our results provide greater insights into the neurotoxic effects of catechol isoquinolines compared with other studies and may be a reference for assessing the involvement of RNA methylation in the pathogenesis of Parkinson's disease.展开更多
Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-asso...Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.展开更多
BACKGROUND Diabetic wound injury is a significant and common complication in individuals with diabetes.N6-methyladenosine(m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complicat...BACKGROUND Diabetic wound injury is a significant and common complication in individuals with diabetes.N6-methyladenosine(m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complications.However,the function of m6A methyltransferase Wilms tumor 1-associated protein(WTAP)in diabetic wound healing remains elusive.AIM To investigate the potential epigenetic regulatory mechanism of WTAP during diabetic wound healing.METHODS Human umbilical vein endothelial cells(HUVECs)were induced with high glucose(HG)to establish in vitro cell model.Male BALB/c mice were intraperitoneally injected with streptozotocin to mimic diabetes,and full-thickness excision was made to mimic diabetic wound healing.HG-induced HUVECs and mouse models were treated with WTAP siRNAs and DNA methyltransferase 1(DNMT1)overexpression vectors.Cell viability and migration ability were detected by cell counting kit-8 and Transwell assays.In vitro angiogenesis was measured using a tube formation experiment.The images of wounds were captured,and re-epithelialization and collagen deposition of skin tissues were analyzed using hematoxylin and eosin staining and Masson’s trichrome staining.RESULTS The expression of several m6A methyltransferases,including METTL3,METTL14,METTL16,KIAA1429,WTAP,and RBM15,were measured.WTAP exhibited the most significant elevation in HG-induced HUVECs compared with the normal control.WTAP depletion notably restored cell viability and enhanced tube formation ability and migration of HUVECs suppressed by HG.The unclosed wound area of mice was smaller in WTAP knockdowntreated mice than in control mice at nine days post-wounding,along with enhanced re-epithelialization rate and collagen deposition.The m6A levels on DNMT1 mRNA in HUVECs were repressed by WTAP knockdown in HUVECs.The mRNA levels and expression of DNMT1 were inhibited by WTAP depletion in HUVECs.Overexpression of DNMT1 in HUVECs notably reversed the effects of WTAP depletion on HG-induced HUVECs.CONCLUSION WTAP expression is elevated in HG-induced HUVECs and epigenetically regulates the m6A modification of DNMT1 to impair diabetic wound healing.展开更多
BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contribut...BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82271283(to XC),91854115(to JW),31970044(to JW)the Natural Science Foundation of Beijing,No.7202001(to XC)the Scientific Research Project of Beijing Educational Committee,No.KM202010005022(to XC)。
文摘Salsolinol(1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline,Sal)is a catechol isoquinoline that causes neurotoxicity and shares structural similarity with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,an environmental toxin that causes Parkinson's disease.However,the mechanism by which Sal mediates dopaminergic neuronal death remains unclear.In this study,we found that Sal significantly enhanced the global level of N~6-methyladenosine(m~6A)RNA methylation in PC12 cells,mainly by inducing the downregulation of the expression of m~6A demethylases fat mass and obesity-associated protein(FTO)and alk B homolog 5(ALKBH5).RNA sequencing analysis showed that Sal downregulated the Hippo signaling pathway.The m~6A reader YTH domain-containing family protein 2(YTHDF2)promoted the degradation of m~6A-containing Yes-associated protein 1(YAP1)mRNA,which is a downstream key effector in the Hippo signaling pathway.Additionally,downregulation of YAP1 promoted autophagy,indicating that the mutual regulation between YAP1 and autophagy can lead to neurotoxicity.These findings reveal the role of Sal on m~6A RNA methylation and suggest that Sal may act as an RNA methylation inducer mediating dopaminergic neuronal death through YAP1 and autophagy.Our results provide greater insights into the neurotoxic effects of catechol isoquinolines compared with other studies and may be a reference for assessing the involvement of RNA methylation in the pathogenesis of Parkinson's disease.
基金supported by the National Natural Science Foundation of China,Nos.82071008(to BL)and 82004001(to XJ)Medical Science and Technology Program of Health Commission of Henan Province,No.LHGJ20210072(to RQ)Science and Technology Department of Henan Province,No.212102310307(to XJ)。
文摘Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.
文摘BACKGROUND Diabetic wound injury is a significant and common complication in individuals with diabetes.N6-methyladenosine(m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complications.However,the function of m6A methyltransferase Wilms tumor 1-associated protein(WTAP)in diabetic wound healing remains elusive.AIM To investigate the potential epigenetic regulatory mechanism of WTAP during diabetic wound healing.METHODS Human umbilical vein endothelial cells(HUVECs)were induced with high glucose(HG)to establish in vitro cell model.Male BALB/c mice were intraperitoneally injected with streptozotocin to mimic diabetes,and full-thickness excision was made to mimic diabetic wound healing.HG-induced HUVECs and mouse models were treated with WTAP siRNAs and DNA methyltransferase 1(DNMT1)overexpression vectors.Cell viability and migration ability were detected by cell counting kit-8 and Transwell assays.In vitro angiogenesis was measured using a tube formation experiment.The images of wounds were captured,and re-epithelialization and collagen deposition of skin tissues were analyzed using hematoxylin and eosin staining and Masson’s trichrome staining.RESULTS The expression of several m6A methyltransferases,including METTL3,METTL14,METTL16,KIAA1429,WTAP,and RBM15,were measured.WTAP exhibited the most significant elevation in HG-induced HUVECs compared with the normal control.WTAP depletion notably restored cell viability and enhanced tube formation ability and migration of HUVECs suppressed by HG.The unclosed wound area of mice was smaller in WTAP knockdowntreated mice than in control mice at nine days post-wounding,along with enhanced re-epithelialization rate and collagen deposition.The m6A levels on DNMT1 mRNA in HUVECs were repressed by WTAP knockdown in HUVECs.The mRNA levels and expression of DNMT1 were inhibited by WTAP depletion in HUVECs.Overexpression of DNMT1 in HUVECs notably reversed the effects of WTAP depletion on HG-induced HUVECs.CONCLUSION WTAP expression is elevated in HG-induced HUVECs and epigenetically regulates the m6A modification of DNMT1 to impair diabetic wound healing.
文摘BACKGROUND Tacrolimus(FK506)is a key calcineurin inhibitor used to prevent organ transplant rejection and is effective in improving graft survival.However,it is linked to hyperglycemia and insulin resistance,contributing to new-onset diabetes after transplantation and negatively affecting islet function.AIM To study the effects of tacrolimus on the insulin signaling pathway of hepatocytes.METHODS HL7702 cells were treated with different concentrations of tacrolimus(0.1 mg/L,1 mg/L,5 mg/L)for 24 hours.The proteins involved in insulin signaling were detected by Western blotting.RESULTS Compared with the control group,phosphorylation of insulin receptor substrate(IRS)1 at Ser 307 and Ser 323 were increased significantly when the tacrolimus concentration reached 1 and 5 mg/L.Phosphorylation of IRS1 at Ser 1101 was also increased,although not significantly.However,phosphorylation of Ribosomal protein S6 kinase beta-1 at Thr 389 was decreased significantly.The levels of phosphorylated glycogen synthase kinase 3αSer 21 and Ser 9 were increased.Surprisingly,phosphorylation of glycogen synthase at Ser 641 was increased.There was no significant change in the activity of glycogen phosphorylase.CONCLUSION Tacrolimus has no direct effect on hepatic glucose metabolism,but inhibits IRS1-mediated insulin signaling.This may be one of the underlying mechanisms by which tacrolimus induces insulin resistance.
