Alzheimer’s disease (AD) is the most prevalent cause of dementia worldwide. Because of the progressive neurodegeneration, individual cognitive and behavioral functions are impaired, affecting the quality of life of m...Alzheimer’s disease (AD) is the most prevalent cause of dementia worldwide. Because of the progressive neurodegeneration, individual cognitive and behavioral functions are impaired, affecting the quality of life of millions of people. Although the exact pathogenesis of AD has not been fully elucidated, amyloid plaques, neurofibrillary tangles (NFTs), and sustaining neuroinflammation dominate its characteristics. As one of the major tau kinases leading to hyperphosphorylation and aggregation of tau, glycogen synthase kinase-3β (GSK-3β) has been drawing great attention in various AD studies. Another research focus of AD in recent years is the inflammasome, a multiprotein complex acting as a regulator in immunological reactions to exogenous and endogenous danger signals, of which the Nod-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome has been studied mostly in AD and proven to play a significant role in AD development by its activation and downstream effects such as caspase-1 maturation and interleukin (IL)-1β release. Studies have shown that the NLRP3 inflammasome is activated in a GSK-3β-dependent way and that inhibition of the NLRP3 inflammasome downregulates GSK-3β, suggesting that these two important proteins are closely related. This article reviews the respective roles of GSK-3β and the NLRP3 inflammasome in AD as well as their relationship and interaction.展开更多
Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic a...Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.展开更多
Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also calle...Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also called protein kinase B, PKB)/glycogen synthase kinase-3β(Akt/GSK-3β) signaling pathway is involved in oxidative stress, the inflammatory response, apoptosis, and autophagy. However, it is not yet clear whether the Akt/GSK-3β pathway participates in the neuroprotective effect of IL-4 against cerebral ischemia/reperfusion injury. In the present study, we established a cerebral ischemia/reperfusion mouse model by middle cerebral artery occlusion for 60 minutes followed by a 24-hour reperfusion. An IL-4/anti-IL-4 complex(10 μg) was intraperitoneally administered 30 minutes before surgery. We found that administration of IL-4 significantly alleviated the neurological deficits, oxidative stress, cell apoptosis, and autophagy and reduced infarct volume of the mice with cerebral ischemia/reperfusion injury 24 hours after reperfusion. Simultaneously, IL-4 activated Akt/GSK-3β signaling pathway. However, an Akt inhibitor LY294002, which was injected at 15 nmol/kg via the tail vein, attenuated the protective effects of IL-4. These findings indicate that IL-4 has a protective effect on cerebral ischemia/reperfusion injury by mitigating oxidative stress, reducing apoptosis, and inhibiting excessive autophagy, and that this mechanism may be related to activation of the Akt/GSK-3β pathway. This animal study was approved by the Animal Ethics Committee of Renmin Hospital of Wuhan University, China(approval No. WDRY2017-K037) on March 9, 2017.展开更多
The present study established global brain ischemia using the four-vessel occlusion method. Following three rounds of reperfusion for 30 seconds, and occlusion for 10 seconds, followed by reperfusion for 48 hours, inf...The present study established global brain ischemia using the four-vessel occlusion method. Following three rounds of reperfusion for 30 seconds, and occlusion for 10 seconds, followed by reperfusion for 48 hours, infarct area, the number of TUNEL-positive cells and Bcl-2 expression were significantly reduced. However, glycogen synthase kinase-3β activity, cortical Bax and caspase-3 expression significantly increased, similar to results following ischemic postconditioning. Our results indicated that ischemic postconditioning may enhance glycogen synthase kinase-3β activity, a downstream molecule of the phosphatase and tensin homolog deleted on chromosome 10/phosphatidylinositol 3-kinase/protein kinase B signaling pathway, which reduces caspase-3 expression to protect the brain against ischemic injury.展开更多
1-methyl-4-phenylpyridinium ion （MPP^＋） induces endoplasmic reticulum stress and activates caspase-12 in PC12 cells, leading to neuronal apoptosis. However, the underlying molecular mechanism remains unknown. The p...1-methyl-4-phenylpyridinium ion （MPP^＋） induces endoplasmic reticulum stress and activates caspase-12 in PC12 cells, leading to neuronal apoptosis. However, the underlying molecular mechanism remains unknown. The present study investigated the regulatory effects of nerve growth factor （Akt activator） and lithium chloride （glycogen synthase kinase-3β inhibitor） on the endoplasmic reticulum stress signaling pathway. The results revealed that MPP＋ induced expression of Bip and C/EBP homologous protein. The upregulation of Bip and C/EBP homologous protein, as well as the decreased pro-caspase-12 level induced by MPP^＋ were inhibited by pretreatment of the nerve growth factor or lithium chloride. These results suggest that the phosphatidylinositol 3 kinase-Aktglycogen synthase kinase-3β pathway is involved in MPP-induced endoplasmic reticulum stress.展开更多
Multiple roles of glycogen synthase kinase-3（GSK-3）in neural tissues：GSK-3 is a serine/threonine kinase that has two isoforms encoded by two different genes,GSK-3αand GSK-3β,in mammals.GSK-3 has several sites of ...Multiple roles of glycogen synthase kinase-3（GSK-3）in neural tissues：GSK-3 is a serine/threonine kinase that has two isoforms encoded by two different genes,GSK-3αand GSK-3β,in mammals.GSK-3 has several sites of serine and tyrosine phosphorylation.展开更多
Objective The mangrove tree Xylocarpus granatum J.Koenig(X.granatum)is a medicinal plant used to treat various diseases in several Asian countries.Many bioactive natural products have been isolated from the plants,par...Objective The mangrove tree Xylocarpus granatum J.Koenig(X.granatum)is a medicinal plant used to treat various diseases in several Asian countries.Many bioactive natural products have been isolated from the plants,particularly several groups of limonoids,including 18 xylogranatins(Xyl-A to R),all of which bear a furyl-δ-lactone core commonly found in limonoids.Based on a structural analogy with the limonoids obacunone and gedunin,we hypothesized that xylogranatins could target the enzyme glycogen synthase kinase-3β(GSK-3β),a major target for the treatment of neurodegenerative pathologies,viral infections,and cancers.Methods We investigated the binding of the 18 xylogranatins to GSK-3βusing molecular docking in comparison with two known reference GSK-3βATP-competitive inhibitors,LY2090314 and AR-A014418.For each compound bound to GSK-3β,the empirical energy of interaction(ΔE)was calculated and compared to that obtained with known GSK-3βinhibitors and limonoid triterpenes that target this enzyme.Results Five compounds were identified as potential GSK-3βbinders,Xyl-A,-C,-J,-N,and-O,for which the calculated empiricalΔE was equivalent to that calculated using the best reference molecule AR-A014418.The best ligand is Xyl-C,which is known to have marked anticancer properties.Binding of Xyl-C to the ATP-binding pocket of GSK-3βpositions the furyl-δ-lactone unit deep into the binding-site cavity.Other xylogranatin derivatives bearing a central pyridine ring or a compact polycyclic structure are much less adapted for GSK-3βbinding.Structure-binding relationships are discussed.Conclusion GSK-3βmay contribute to the anticancer effects of X.granatum extract.This study paves the way for the identification of other furyl-δ-lactone-containing limonoids as GSK-3βmodulators.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
Our recent studies with cultured retinal pigment epithelium cells suggested that overexpression of interleukin 17 receptor C（IL-17RC）,a phenomenon observed in peripheral blood and chorioretinal tissues with age-rela...Our recent studies with cultured retinal pigment epithelium cells suggested that overexpression of interleukin 17 receptor C（IL-17RC）,a phenomenon observed in peripheral blood and chorioretinal tissues with age-related macular degeneration（AMD）,was associated with altered activation of phosphatidylinositide 3-kinase（PI3K）,Akt,and glycogen synthase kinase 3（GSK3）.We wondered whether or not altered PI3 K,Akt,and GSK3 activities could be detected in peripheral blood mononuclear cells（PBMC） obtained from AMD patients.In the patients＇ PBMC,absent or reduced serine-phosphorylation of GSK3α or GSK3β was observed,which was accompanied with increased phosphorylation of GSK3 substrates（e.g.CCAAT enhancer binding protein a,insulin receptor substrate 1,and TAU）,indicative of enhanced GSK3 activation.In addition,decreased protein mass of PI3K85α and tyrosinephosphorylation of PI3K50α was present in PBMC of the AMD patients,suggesting impaired PI3 K activation.Moreover,abnormally lowered molecular weight forms of Akt and GSK3 were detected in PBMC of the AMD patients.These data demonstrate that despite the presence of high levels of IL-17 RC,Wnt-3a and vascular endothelial growth factor,the PI3K/Akt/GSK3 signaling pathway is insensitive to these stimuli in PBMC of the AMD patients.Thus,measurement of PI3K/Akt/GSK3 expression and activity in PBMC may serve as a surrogate biomarker for AMD.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.92049107 and No.31929002)the Innovative Research Groups of the National Natural Science Foundation of China(No.81721005)the Academic Frontier Youth Team Project to Xiaochuan Wang from Huazhong University of Science and Technology.
文摘Alzheimer’s disease (AD) is the most prevalent cause of dementia worldwide. Because of the progressive neurodegeneration, individual cognitive and behavioral functions are impaired, affecting the quality of life of millions of people. Although the exact pathogenesis of AD has not been fully elucidated, amyloid plaques, neurofibrillary tangles (NFTs), and sustaining neuroinflammation dominate its characteristics. As one of the major tau kinases leading to hyperphosphorylation and aggregation of tau, glycogen synthase kinase-3β (GSK-3β) has been drawing great attention in various AD studies. Another research focus of AD in recent years is the inflammasome, a multiprotein complex acting as a regulator in immunological reactions to exogenous and endogenous danger signals, of which the Nod-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome has been studied mostly in AD and proven to play a significant role in AD development by its activation and downstream effects such as caspase-1 maturation and interleukin (IL)-1β release. Studies have shown that the NLRP3 inflammasome is activated in a GSK-3β-dependent way and that inhibition of the NLRP3 inflammasome downregulates GSK-3β, suggesting that these two important proteins are closely related. This article reviews the respective roles of GSK-3β and the NLRP3 inflammasome in AD as well as their relationship and interaction.
文摘Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.
基金supported by the National Natural Science Foundation of China,Nos.81901994(to BZ)and 81571147(to XXX)the Natural Science Foundation of Hubei Province,China,No.2019CFC847(to WWG)the Fundamental Research Funds for the Central Universities,China,No.2042018kf0149(to ML)
文摘Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also called protein kinase B, PKB)/glycogen synthase kinase-3β(Akt/GSK-3β) signaling pathway is involved in oxidative stress, the inflammatory response, apoptosis, and autophagy. However, it is not yet clear whether the Akt/GSK-3β pathway participates in the neuroprotective effect of IL-4 against cerebral ischemia/reperfusion injury. In the present study, we established a cerebral ischemia/reperfusion mouse model by middle cerebral artery occlusion for 60 minutes followed by a 24-hour reperfusion. An IL-4/anti-IL-4 complex(10 μg) was intraperitoneally administered 30 minutes before surgery. We found that administration of IL-4 significantly alleviated the neurological deficits, oxidative stress, cell apoptosis, and autophagy and reduced infarct volume of the mice with cerebral ischemia/reperfusion injury 24 hours after reperfusion. Simultaneously, IL-4 activated Akt/GSK-3β signaling pathway. However, an Akt inhibitor LY294002, which was injected at 15 nmol/kg via the tail vein, attenuated the protective effects of IL-4. These findings indicate that IL-4 has a protective effect on cerebral ischemia/reperfusion injury by mitigating oxidative stress, reducing apoptosis, and inhibiting excessive autophagy, and that this mechanism may be related to activation of the Akt/GSK-3β pathway. This animal study was approved by the Animal Ethics Committee of Renmin Hospital of Wuhan University, China(approval No. WDRY2017-K037) on March 9, 2017.
基金sponsored by the National Natural Science Foundation of China,No.81170768
文摘The present study established global brain ischemia using the four-vessel occlusion method. Following three rounds of reperfusion for 30 seconds, and occlusion for 10 seconds, followed by reperfusion for 48 hours, infarct area, the number of TUNEL-positive cells and Bcl-2 expression were significantly reduced. However, glycogen synthase kinase-3β activity, cortical Bax and caspase-3 expression significantly increased, similar to results following ischemic postconditioning. Our results indicated that ischemic postconditioning may enhance glycogen synthase kinase-3β activity, a downstream molecule of the phosphatase and tensin homolog deleted on chromosome 10/phosphatidylinositol 3-kinase/protein kinase B signaling pathway, which reduces caspase-3 expression to protect the brain against ischemic injury.
基金the National Natural Science Foundation of China, No. 30860085a grant from the Candidates of Young and Middle-Aged Academic Leaders of Yunnan Province, No. 2006PY01-07the Natural Science Foundation of Yunnan Province, No. 2007C177M
文摘1-methyl-4-phenylpyridinium ion （MPP^＋） induces endoplasmic reticulum stress and activates caspase-12 in PC12 cells, leading to neuronal apoptosis. However, the underlying molecular mechanism remains unknown. The present study investigated the regulatory effects of nerve growth factor （Akt activator） and lithium chloride （glycogen synthase kinase-3β inhibitor） on the endoplasmic reticulum stress signaling pathway. The results revealed that MPP＋ induced expression of Bip and C/EBP homologous protein. The upregulation of Bip and C/EBP homologous protein, as well as the decreased pro-caspase-12 level induced by MPP^＋ were inhibited by pretreatment of the nerve growth factor or lithium chloride. These results suggest that the phosphatidylinositol 3 kinase-Aktglycogen synthase kinase-3β pathway is involved in MPP-induced endoplasmic reticulum stress.
文摘Multiple roles of glycogen synthase kinase-3（GSK-3）in neural tissues：GSK-3 is a serine/threonine kinase that has two isoforms encoded by two different genes,GSK-3αand GSK-3β,in mammals.GSK-3 has several sites of serine and tyrosine phosphorylation.
文摘Objective The mangrove tree Xylocarpus granatum J.Koenig(X.granatum)is a medicinal plant used to treat various diseases in several Asian countries.Many bioactive natural products have been isolated from the plants,particularly several groups of limonoids,including 18 xylogranatins(Xyl-A to R),all of which bear a furyl-δ-lactone core commonly found in limonoids.Based on a structural analogy with the limonoids obacunone and gedunin,we hypothesized that xylogranatins could target the enzyme glycogen synthase kinase-3β(GSK-3β),a major target for the treatment of neurodegenerative pathologies,viral infections,and cancers.Methods We investigated the binding of the 18 xylogranatins to GSK-3βusing molecular docking in comparison with two known reference GSK-3βATP-competitive inhibitors,LY2090314 and AR-A014418.For each compound bound to GSK-3β,the empirical energy of interaction(ΔE)was calculated and compared to that obtained with known GSK-3βinhibitors and limonoid triterpenes that target this enzyme.Results Five compounds were identified as potential GSK-3βbinders,Xyl-A,-C,-J,-N,and-O,for which the calculated empiricalΔE was equivalent to that calculated using the best reference molecule AR-A014418.The best ligand is Xyl-C,which is known to have marked anticancer properties.Binding of Xyl-C to the ATP-binding pocket of GSK-3βpositions the furyl-δ-lactone unit deep into the binding-site cavity.Other xylogranatin derivatives bearing a central pyridine ring or a compact polycyclic structure are much less adapted for GSK-3βbinding.Structure-binding relationships are discussed.Conclusion GSK-3βmay contribute to the anticancer effects of X.granatum extract.This study paves the way for the identification of other furyl-δ-lactone-containing limonoids as GSK-3βmodulators.
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.
基金supported by intramural research funding of National Center for Complementary and Alternative Medicine(now is National Center for Complementary and Integrative Health),NIH,the US Department of Health and Human Services(to X.L.)and an operating grant(MOP 123279)from Canadian Institutes for Health Research(to Z.Y.)
文摘Our recent studies with cultured retinal pigment epithelium cells suggested that overexpression of interleukin 17 receptor C（IL-17RC）,a phenomenon observed in peripheral blood and chorioretinal tissues with age-related macular degeneration（AMD）,was associated with altered activation of phosphatidylinositide 3-kinase（PI3K）,Akt,and glycogen synthase kinase 3（GSK3）.We wondered whether or not altered PI3 K,Akt,and GSK3 activities could be detected in peripheral blood mononuclear cells（PBMC） obtained from AMD patients.In the patients＇ PBMC,absent or reduced serine-phosphorylation of GSK3α or GSK3β was observed,which was accompanied with increased phosphorylation of GSK3 substrates（e.g.CCAAT enhancer binding protein a,insulin receptor substrate 1,and TAU）,indicative of enhanced GSK3 activation.In addition,decreased protein mass of PI3K85α and tyrosinephosphorylation of PI3K50α was present in PBMC of the AMD patients,suggesting impaired PI3 K activation.Moreover,abnormally lowered molecular weight forms of Akt and GSK3 were detected in PBMC of the AMD patients.These data demonstrate that despite the presence of high levels of IL-17 RC,Wnt-3a and vascular endothelial growth factor,the PI3K/Akt/GSK3 signaling pathway is insensitive to these stimuli in PBMC of the AMD patients.Thus,measurement of PI3K/Akt/GSK3 expression and activity in PBMC may serve as a surrogate biomarker for AMD.
