In the present study,Fmr1 knockout mice （KO mice） were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error cou...In the present study,Fmr1 knockout mice （KO mice） were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts,indicating a learning and memory disorder.After treatment with 30,60,90,120,or 200 mg/kg lithium chloride,the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated,in particular,the 200 mg/kg lithium chloride treatment had the most significant effect.Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta,an inactive form of glycogen synthase kinase 3 beta,in the cerebral cortex and hippocampus of the Fmr1 KO mice.These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice,possibly by inhibiting glycogen synthase kinase 3 beta activity.展开更多
To examine the role of glycogen synthase kinase 3 （GSK-3） in the apoptosis of pancreatic β-cells to better understand the pathogenesis and to find new approach to the treatment of type 2 diabetes, apoptosis was ind...To examine the role of glycogen synthase kinase 3 （GSK-3） in the apoptosis of pancreatic β-cells to better understand the pathogenesis and to find new approach to the treatment of type 2 diabetes, apoptosis was induced by oleic acid （OA） in INS-1 cells and the activity of GSK-3 was inhibited by LiCl. The PI staining and flow cytometry were employed for the evaluation of apoptosis. The phosphorylation level of GSK-3 was detected by Western blotting. The results showed that OA at 0.4 mmol/L could cause conspicuous apoptosis of INS- 1 cells and the activity of GSK-3 was significantly increased. After the treatment with 24 mmolFL of LiCl, a inhibitor of GSK-3, the OA-induced apoptosis of INS-1 cells was lessened and the phosphorylation of GSK-3 was increased remarkably. It is concluded that GSK-3 activation plays an important role in OA-induced apoptosis in pancreatic β-cells and inhibition of the GSK-3 activity can effectively protect INS-1 cells from the OA-induced apoptosis. Our study provides a new experimental basis and target for the clinical treatment of type-2 diabetes.展开更多
Objective:Xiaobuxintang-2(XBXT-2)has antidepressant effects,but the underlying mechanism is still unclear.In this study,we used the corticosterone-induced depression mouse model to study the antidepressant effect of X...Objective:Xiaobuxintang-2(XBXT-2)has antidepressant effects,but the underlying mechanism is still unclear.In this study,we used the corticosterone-induced depression mouse model to study the antidepressant effect of XBXT-2and its underlying mechanisms.Methods:A mouse model of depression was induced by corticosterone.The mice were divided into 5 groups:(i)control group,(ii)corticosterone group(CORT),(iii)corticosterone+XBXT-2(CORT+XBXT-2)group,(iv)corticosterone+XBXT-2+lentiviral empty group(CORT+XBXT-2+no-load),(v)corticosterone+XBXT-2+lentivirus GSK3βOverexpression group(CORT+XBXT-2+GSK3β).The expression level of GSK3βin the hippocampus was detected by immunoblotting,and the depression status of the mice was evaluated by forced swimming test and tail suspension test.Results:The GSK3βlentivirus induced the high expression of GSK3βin the hippocampus of mice,and the mRNA and protein levels were significantly increased compared with the control group.The immobility time is significantly increased in corticosterone injection-induced depression model mice(CORT group),and XBXT-2 can effectively reduce the immobility time of depression model mice.Overexpression of GFP empty lentivirus did not affect mouse behavior,whereas overexpression of GSK3βsignificantly increased immobility time in depression model mice according to forced swimming and tail suspension experiments.Conclusion:High expression of GSK3βin the hippocampus of mice can inhibit the therapeutic effect of XBXT-2 on the corticosterone-induced depression in mice.展开更多
Myocardial ischemia/reperfusion injury can lead to severe brain injury.Glycogen synthase kinase 3 beta is known to be involved in myocardial ischemia/reperfusion injury and diabetes mellitus.However,the precise role o...Myocardial ischemia/reperfusion injury can lead to severe brain injury.Glycogen synthase kinase 3 beta is known to be involved in myocardial ischemia/reperfusion injury and diabetes mellitus.However,the precise role of glycogen synthase kinase 3 beta in myocardial ischemia/reperfusion injury-induced brain injury is unclear.In this study,we observed the effects of glycogen synthase kinase 3 beta on brain injury induced by myocardial ischemia/reperfusion injury in diabetic rats.Rat models of diabetes mellitus were generated via intraperitoneal injection of streptozotocin.Models of myocardial ischemia/reperfusion injury were generated by occluding the anterior descending branch of the left coronary artery.Post-conditioning comprised three cycles of ischemia/reperfusion.Immunohistochemical staining and western blot assays demonstrated that after 48 hours of reperfusion,the structure of the brain was seriously damaged in the experimental rats compared with normal controls.Expression of Bax,interleukin-6,interleukin-8,terminal deoxynucleotidyl transferase d UTP nick end labeling,and cleaved caspase-3 in the brain was significantly increased,while expression of Bcl-2,interleukin-10,and phospho-glycogen synthase kinase 3 beta was decreased.Diabetes mellitus can aggravate inflammatory reactions and apoptosis.Ischemic post-conditioning with glycogen synthase kinase 3 beta inhibitor lithium chloride can effectively reverse these changes.Our results showed that myocardial ischemic post-conditioning attenuated myocardial ischemia/reperfusion injury-induced brain injury by activating glycogen synthase kinase 3 beta.According to these results,glycogen synthase kinase 3 beta appears to be an important factor in brain injury induced by myocardial ischemia/reperfusion injury.展开更多
Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspr...Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspring sex ratio is approximately 50%.At present,artificial insemination after the separation of X/Y sperm using flow cytometry is the primary means of controlling the sex of livestock offspring.However,flow cytometry has not been successfully utilised for the separation of X/Y sperm aimed at sexing control in dairy goats.Results:In this study,a novel,simple goat sperm sexing technology that activates the toll-like receptor 7/8(TLR7/8),thereby inhibiting X-sperm motility,was investigated.Our results showed that the TLR7/8 coding goat Xchromosome was expressed in approximately 50%of round spermatids in the testis and sperm,as measured from cross-sections of the epididymis and ejaculate,respectively.Importantly,TLR7/8 was located at the tail of the Xsperm.Upon TLR7/8 activation,phosphorylated forms of glycogen synthase kinaseα/β(GSK3α/β)and nuclear factor kappa-B(NF-κB)were detected in the X-sperm,causing reduced mitochondrial activity,ATP levels,and sperm motility.High-motility Y-sperm segregated to the upper layer and the low-motility X-sperm,to the lower layer.Following in vitro fertilisation using the TLR7/8-activated sperm from the lower layer,80.52±6.75%of the embryos were XX females.The TLR7/8-activated sperm were subsequently used for in vivo embryo production via the superovulatory response;nine embryos were collected from the uterus of two does that conceived.Eight of these were XX embryos,and one was an XY embryo.Conclusions:Our study reveals a novel TLR7/8 signalling mechanism that affects X-sperm motility via the GSK3α/β-hexokinase pathway;this technique could be used to facilitate the efficient production of sexed dairy goat embryos.展开更多
Previous studies have shown that fibroblast growth factor 13 is downregulated in the brain of both Alzheimer’s disease mouse models and patients,and that it plays a vital role in the learning and memory.However,the u...Previous studies have shown that fibroblast growth factor 13 is downregulated in the brain of both Alzheimer’s disease mouse models and patients,and that it plays a vital role in the learning and memory.However,the underlying mechanisms of fibroblast growth factor 13 in Alzheimer’s disease remain unclear.In this study,we established rat models of Alzheimer’s disease by stereotaxic injection of amyloid-β(Aβ_(1-42))-induced into bilateral hippocampus.We also injected lentivirus containing fibroblast growth factor 13 into bilateral hippocampus to overexpress fibroblast growth factor 13.The expression of fibroblast growth factor 13 was downregulated in the brain of the Alzheimer’s disease model rats.After overexpression of fibroblast growth factor 13,learning and memory abilities of the Alzheimer’s disease model rats were remarkably improved.Fibroblast growth factor 13 overexpression increased brain expression levels of oxidative stress-related markers glutathione,superoxide dismutase,phosphatidylinositol-3-kinase,AKT and glycogen synthase kinase 3β,and anti-apoptotic factor BCL.Furthermore,fibroblast growth factor 13 overexpression decreased the number of apoptotic cells,expression of pro-apoptotic factor BAX,cleaved-caspase 3 and amyloid-βexpression,and levels of tau phosphorylation,malondialdehyde,reactive oxygen species and acetylcholinesterase in the brain of Alzheimer’s disease model rats.The changes were reversed by the phosphatidylinositol-3-kinase inhibitor LY294002.These findings suggest that overexpression of fibroblast growth factor 13 improved neuronal damage in a rat model of Alzheimer’s disease through activation of the phosphatidylinositol-3-kinase/AKT/glycogen synthase kinase 3βsignaling pathway.展开更多
Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in hig...Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.展开更多
Insulin resistance is the pathophysiological basis of many diseases.Overcoming early insulin resistance highly significant in prevention diabetes,non-alcoholic fatty liver,and atherosclerosis.The present study aimed a...Insulin resistance is the pathophysiological basis of many diseases.Overcoming early insulin resistance highly significant in prevention diabetes,non-alcoholic fatty liver,and atherosclerosis.The present study aimed at evaluating the therapeutic effects of baicalin on insulin resistance and skeletal muscle ectopic fat storage in high fat diet-induced mice,and exploring the potential molecular mechanisms.Insulin resistance in mice was induced with a high fat diet for 16 weeks.Animals were then treated with three different doses of baicalin(100,200,and 400 mg·kg^(-1)·d^(-1)for 14 weeks.Fasting blood glucose,fasting serum insulin,glucose tolerance test(GTT),insulin tolerance test(ITT),and skeletal muscle lipid deposition were measured.Additionally,the AMP-activated protein kinase/acetyl-CoA carboxylase and protein kinase B/Glycogen synthase kinase 3 beta pathways in skeletal muscle were further evaluated.Baicalin significantly reduced the levels of fasting blood glucose and fasting serum insulin and attenuated high fat diet induced glucose tolerance and insulin tolerance.Moreover,insulin resistance was significantly reversed.Pathological analysis revealed baicalin dose-dependently decreased the degree of the ectopic fat storage in skeletal muscle.The properties of baicalin were mediated,at least in part,by inhibition of the AMPK/ACC pathway,a key regulator of de novo lipogenesis and activation of the Akt/GSK-3β pathway,a key regulator of Glycogen synthesis.These data suggest that baicalin,at dose up to 400 mg·kg^(-1)·d^(-1),is safe and able to attenuate insulin resistance and skeletal muscle ectopic fat storage,through modulating the skeletal muscle AMPK/ACC pathway and Akt/GSK-3β pathway.展开更多
Background： Sevoflurane preconditioning （SP） has been shown to invoke potent myocardial protection in animal studies and clinical trials. However, the mechanisms underlying SP are complex and not yet well understoo...Background： Sevoflurane preconditioning （SP） has been shown to invoke potent myocardial protection in animal studies and clinical trials. However, the mechanisms underlying SP are complex and not yet well understood. We investigated the hypothesis that the cardioprotection afforded by SP is mediated via the Writ/glycogen synthase kinase 3β（GSK3β）/β-catenin signaling pathway. Methods： Two models were established： A Langendorffperfused rat heart model and the H9C2 cell hypoxia/reoxygenation model. Both rats and H9C2 cells were randomly divided into 6 groups as follows： S group, ischemia-reperfusion （I/R） group, DMSO group, IWP group, SP group, and SP ＋ IWP group. Hemodynamic parameters, lactate dehydrogenase （LDH） activity in coronary effluent and cell culture supernatant, and the infarct size were measured to evaluate myocardial ischemia-reperfusion injuries. To determine the activity of Wnt/GSK3β/β-catenin signaling pathway, the expressions of Wnt3a, phospho-GSK3β, and β-catenin were measured by Western blotting. Results： SP improved cardiac function recovery, reduced infarct size （18 ±2% in the SP group compared with 35 ± 4% in the 1/R group; P 〈 0.05）, decreased LDH activity in coronary effluent, and culture supematant. IWP-2, an inhibitor of Wnt, abolished the cardioprotection by SR In addition, Western blotting analysis demonstrated that the expressions of Wnt3a, phospho-GSK3β, and β-catenin significantly （P 〈 0.05） increased in the I/R group, compared with the S group; and compared to I/R group, SP significantly （P 〈 0.05） increased Wnt3a, phospho-GSK3 β, and β-catenin expressions. Pretreatment with IWP-2 significantly （P 〈 0.05） abolished SP-induced Wnt/GSK3β/β-catenin signaling activation. Conclusions： The results showed for the first time that cardioprotection afforded by SP may be mediated partly via the Wnt/GSK3β/β-catenin signaling pathway.展开更多
基金the National Natural Science Foundation of China,No.30870876the Natural Science Foundation of Guangdong Province,No.815101700100005+2 种基金the Science and Technology Program of Guangdong Province,No.2005B60302004,2008B030301371,2009B030801368the Traditional Chinese Medicineand Combination of Traditional Chinese and Western Medicine Program of Guangzhou,No.2008A52the Medical and Health Scientific Research Program of Guangzhou,No.2009-YB-167
文摘In the present study,Fmr1 knockout mice （KO mice） were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts,indicating a learning and memory disorder.After treatment with 30,60,90,120,or 200 mg/kg lithium chloride,the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated,in particular,the 200 mg/kg lithium chloride treatment had the most significant effect.Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta,an inactive form of glycogen synthase kinase 3 beta,in the cerebral cortex and hippocampus of the Fmr1 KO mice.These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice,possibly by inhibiting glycogen synthase kinase 3 beta activity.
基金This project was supported by a grant from National Natural Sciences Foundation of China (No 30672262)
文摘To examine the role of glycogen synthase kinase 3 （GSK-3） in the apoptosis of pancreatic β-cells to better understand the pathogenesis and to find new approach to the treatment of type 2 diabetes, apoptosis was induced by oleic acid （OA） in INS-1 cells and the activity of GSK-3 was inhibited by LiCl. The PI staining and flow cytometry were employed for the evaluation of apoptosis. The phosphorylation level of GSK-3 was detected by Western blotting. The results showed that OA at 0.4 mmol/L could cause conspicuous apoptosis of INS- 1 cells and the activity of GSK-3 was significantly increased. After the treatment with 24 mmolFL of LiCl, a inhibitor of GSK-3, the OA-induced apoptosis of INS-1 cells was lessened and the phosphorylation of GSK-3 was increased remarkably. It is concluded that GSK-3 activation plays an important role in OA-induced apoptosis in pancreatic β-cells and inhibition of the GSK-3 activity can effectively protect INS-1 cells from the OA-induced apoptosis. Our study provides a new experimental basis and target for the clinical treatment of type-2 diabetes.
文摘Objective:Xiaobuxintang-2(XBXT-2)has antidepressant effects,but the underlying mechanism is still unclear.In this study,we used the corticosterone-induced depression mouse model to study the antidepressant effect of XBXT-2and its underlying mechanisms.Methods:A mouse model of depression was induced by corticosterone.The mice were divided into 5 groups:(i)control group,(ii)corticosterone group(CORT),(iii)corticosterone+XBXT-2(CORT+XBXT-2)group,(iv)corticosterone+XBXT-2+lentiviral empty group(CORT+XBXT-2+no-load),(v)corticosterone+XBXT-2+lentivirus GSK3βOverexpression group(CORT+XBXT-2+GSK3β).The expression level of GSK3βin the hippocampus was detected by immunoblotting,and the depression status of the mice was evaluated by forced swimming test and tail suspension test.Results:The GSK3βlentivirus induced the high expression of GSK3βin the hippocampus of mice,and the mRNA and protein levels were significantly increased compared with the control group.The immobility time is significantly increased in corticosterone injection-induced depression model mice(CORT group),and XBXT-2 can effectively reduce the immobility time of depression model mice.Overexpression of GFP empty lentivirus did not affect mouse behavior,whereas overexpression of GSK3βsignificantly increased immobility time in depression model mice according to forced swimming and tail suspension experiments.Conclusion:High expression of GSK3βin the hippocampus of mice can inhibit the therapeutic effect of XBXT-2 on the corticosterone-induced depression in mice.
基金supported by the National Natural Science Foundation of China,No.81471844the Natural Science Foundation of Hubei Province of China,No.2016CFB167the Basic Scientific Research Foundation of Central Universities,No.2042017kf0147
文摘Myocardial ischemia/reperfusion injury can lead to severe brain injury.Glycogen synthase kinase 3 beta is known to be involved in myocardial ischemia/reperfusion injury and diabetes mellitus.However,the precise role of glycogen synthase kinase 3 beta in myocardial ischemia/reperfusion injury-induced brain injury is unclear.In this study,we observed the effects of glycogen synthase kinase 3 beta on brain injury induced by myocardial ischemia/reperfusion injury in diabetic rats.Rat models of diabetes mellitus were generated via intraperitoneal injection of streptozotocin.Models of myocardial ischemia/reperfusion injury were generated by occluding the anterior descending branch of the left coronary artery.Post-conditioning comprised three cycles of ischemia/reperfusion.Immunohistochemical staining and western blot assays demonstrated that after 48 hours of reperfusion,the structure of the brain was seriously damaged in the experimental rats compared with normal controls.Expression of Bax,interleukin-6,interleukin-8,terminal deoxynucleotidyl transferase d UTP nick end labeling,and cleaved caspase-3 in the brain was significantly increased,while expression of Bcl-2,interleukin-10,and phospho-glycogen synthase kinase 3 beta was decreased.Diabetes mellitus can aggravate inflammatory reactions and apoptosis.Ischemic post-conditioning with glycogen synthase kinase 3 beta inhibitor lithium chloride can effectively reverse these changes.Our results showed that myocardial ischemic post-conditioning attenuated myocardial ischemia/reperfusion injury-induced brain injury by activating glycogen synthase kinase 3 beta.According to these results,glycogen synthase kinase 3 beta appears to be an important factor in brain injury induced by myocardial ischemia/reperfusion injury.
基金This research was supported by the National Natural Science Foundation of China(31672425)Shaanxi Province Key R&D Program(2018ZDXM-NY-043,2020ZDLNY02–04).
文摘Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspring sex ratio is approximately 50%.At present,artificial insemination after the separation of X/Y sperm using flow cytometry is the primary means of controlling the sex of livestock offspring.However,flow cytometry has not been successfully utilised for the separation of X/Y sperm aimed at sexing control in dairy goats.Results:In this study,a novel,simple goat sperm sexing technology that activates the toll-like receptor 7/8(TLR7/8),thereby inhibiting X-sperm motility,was investigated.Our results showed that the TLR7/8 coding goat Xchromosome was expressed in approximately 50%of round spermatids in the testis and sperm,as measured from cross-sections of the epididymis and ejaculate,respectively.Importantly,TLR7/8 was located at the tail of the Xsperm.Upon TLR7/8 activation,phosphorylated forms of glycogen synthase kinaseα/β(GSK3α/β)and nuclear factor kappa-B(NF-κB)were detected in the X-sperm,causing reduced mitochondrial activity,ATP levels,and sperm motility.High-motility Y-sperm segregated to the upper layer and the low-motility X-sperm,to the lower layer.Following in vitro fertilisation using the TLR7/8-activated sperm from the lower layer,80.52±6.75%of the embryos were XX females.The TLR7/8-activated sperm were subsequently used for in vivo embryo production via the superovulatory response;nine embryos were collected from the uterus of two does that conceived.Eight of these were XX embryos,and one was an XY embryo.Conclusions:Our study reveals a novel TLR7/8 signalling mechanism that affects X-sperm motility via the GSK3α/β-hexokinase pathway;this technique could be used to facilitate the efficient production of sexed dairy goat embryos.
文摘Previous studies have shown that fibroblast growth factor 13 is downregulated in the brain of both Alzheimer’s disease mouse models and patients,and that it plays a vital role in the learning and memory.However,the underlying mechanisms of fibroblast growth factor 13 in Alzheimer’s disease remain unclear.In this study,we established rat models of Alzheimer’s disease by stereotaxic injection of amyloid-β(Aβ_(1-42))-induced into bilateral hippocampus.We also injected lentivirus containing fibroblast growth factor 13 into bilateral hippocampus to overexpress fibroblast growth factor 13.The expression of fibroblast growth factor 13 was downregulated in the brain of the Alzheimer’s disease model rats.After overexpression of fibroblast growth factor 13,learning and memory abilities of the Alzheimer’s disease model rats were remarkably improved.Fibroblast growth factor 13 overexpression increased brain expression levels of oxidative stress-related markers glutathione,superoxide dismutase,phosphatidylinositol-3-kinase,AKT and glycogen synthase kinase 3β,and anti-apoptotic factor BCL.Furthermore,fibroblast growth factor 13 overexpression decreased the number of apoptotic cells,expression of pro-apoptotic factor BAX,cleaved-caspase 3 and amyloid-βexpression,and levels of tau phosphorylation,malondialdehyde,reactive oxygen species and acetylcholinesterase in the brain of Alzheimer’s disease model rats.The changes were reversed by the phosphatidylinositol-3-kinase inhibitor LY294002.These findings suggest that overexpression of fibroblast growth factor 13 improved neuronal damage in a rat model of Alzheimer’s disease through activation of the phosphatidylinositol-3-kinase/AKT/glycogen synthase kinase 3βsignaling pathway.
基金supported by National Natural Science Foundation of China(32072212)Multi-Year Research Grant of University of Macao(MYRG2018-00169-ICMS)+5 种基金Science and Technology Development Fund of Macao(FDCT)(0098/2020/A)MICINN supporting the Ramón y Cajal grant for M.A.Prieto(RYC-201722891)Jianbo Xiao(RYC2020-030365-I)Xunta de Galicia supporting the Axudas Conecta Peme,the IN852A 2018/58 Neuro Food Project,the program EXCELENCIA-ED431F 2020/12the pre-doctoral grants of P.García-Oliveira(ED481A-2019/295)to Ibero-American Program on Science and Technology(CYTED-AQUA-CIBUS,P317RT0003).
文摘Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.
基金supported by a grant provided by Southeast University(No.9224007044)
文摘Insulin resistance is the pathophysiological basis of many diseases.Overcoming early insulin resistance highly significant in prevention diabetes,non-alcoholic fatty liver,and atherosclerosis.The present study aimed at evaluating the therapeutic effects of baicalin on insulin resistance and skeletal muscle ectopic fat storage in high fat diet-induced mice,and exploring the potential molecular mechanisms.Insulin resistance in mice was induced with a high fat diet for 16 weeks.Animals were then treated with three different doses of baicalin(100,200,and 400 mg·kg^(-1)·d^(-1)for 14 weeks.Fasting blood glucose,fasting serum insulin,glucose tolerance test(GTT),insulin tolerance test(ITT),and skeletal muscle lipid deposition were measured.Additionally,the AMP-activated protein kinase/acetyl-CoA carboxylase and protein kinase B/Glycogen synthase kinase 3 beta pathways in skeletal muscle were further evaluated.Baicalin significantly reduced the levels of fasting blood glucose and fasting serum insulin and attenuated high fat diet induced glucose tolerance and insulin tolerance.Moreover,insulin resistance was significantly reversed.Pathological analysis revealed baicalin dose-dependently decreased the degree of the ectopic fat storage in skeletal muscle.The properties of baicalin were mediated,at least in part,by inhibition of the AMPK/ACC pathway,a key regulator of de novo lipogenesis and activation of the Akt/GSK-3β pathway,a key regulator of Glycogen synthesis.These data suggest that baicalin,at dose up to 400 mg·kg^(-1)·d^(-1),is safe and able to attenuate insulin resistance and skeletal muscle ectopic fat storage,through modulating the skeletal muscle AMPK/ACC pathway and Akt/GSK-3β pathway.
文摘Background： Sevoflurane preconditioning （SP） has been shown to invoke potent myocardial protection in animal studies and clinical trials. However, the mechanisms underlying SP are complex and not yet well understood. We investigated the hypothesis that the cardioprotection afforded by SP is mediated via the Writ/glycogen synthase kinase 3β（GSK3β）/β-catenin signaling pathway. Methods： Two models were established： A Langendorffperfused rat heart model and the H9C2 cell hypoxia/reoxygenation model. Both rats and H9C2 cells were randomly divided into 6 groups as follows： S group, ischemia-reperfusion （I/R） group, DMSO group, IWP group, SP group, and SP ＋ IWP group. Hemodynamic parameters, lactate dehydrogenase （LDH） activity in coronary effluent and cell culture supernatant, and the infarct size were measured to evaluate myocardial ischemia-reperfusion injuries. To determine the activity of Wnt/GSK3β/β-catenin signaling pathway, the expressions of Wnt3a, phospho-GSK3β, and β-catenin were measured by Western blotting. Results： SP improved cardiac function recovery, reduced infarct size （18 ±2% in the SP group compared with 35 ± 4% in the 1/R group; P 〈 0.05）, decreased LDH activity in coronary effluent, and culture supematant. IWP-2, an inhibitor of Wnt, abolished the cardioprotection by SR In addition, Western blotting analysis demonstrated that the expressions of Wnt3a, phospho-GSK3β, and β-catenin significantly （P 〈 0.05） increased in the I/R group, compared with the S group; and compared to I/R group, SP significantly （P 〈 0.05） increased Wnt3a, phospho-GSK3 β, and β-catenin expressions. Pretreatment with IWP-2 significantly （P 〈 0.05） abolished SP-induced Wnt/GSK3β/β-catenin signaling activation. Conclusions： The results showed for the first time that cardioprotection afforded by SP may be mediated partly via the Wnt/GSK3β/β-catenin signaling pathway.
