Objective We performed experiments using Neuregulin-1β （NRG-1β） treatment to determine a mechanism for the protective role derived from its beneficial effects by remodeling gap junctions （GJs） during heart failu...Objective We performed experiments using Neuregulin-1β （NRG-1β） treatment to determine a mechanism for the protective role derived from its beneficial effects by remodeling gap junctions （GJs） during heart failure （HF）. Methods Rat models of I-IF were established by aortocaval fistula. Forty-eight rats were divided randomly into the HF （HF, n = 16）, NRG-1β trealanent （NRG, n = 16）, and sham operation （S, n = 16） group. The rats in the NRG group were administered NRG-1β （10 μg/kg per day） for 7 days via the tail vein, whereas the other groups were injected with the same doses of saline, Twelve weeks after operation, Connexin 43 （Cx43） expression in single myocytes obtained from the left ventricle was determined by immunocytochemistry. Total protein was extracted from frozen left ventricular tissues for immunoblotting assay, and the ultrastmcture of myocytes was observed by transmission electron microscopy. Results Compared with the HF group, the cardiac fimction of rats in the NRG group was markedly improved, irregular distribution and deceased Cx43 expression were relieved. The ultrastmcture of myocytes was seriously damaged in HF rats, and NRG-1β reduced these pathological damages. Conclusions Short-term NRG-1β treatment can rescue pump failure in experimental models of volume overload-induced HF, which is related to the recovery of GJs structure and the improvement of Cx43 expression.展开更多
Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders....Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.展开更多
分析X-连锁腓骨肌萎缩症1型(X-linked Charcot-Marie-Tooth disease type 1,CMT1X)一家系的临床表现、电生理与突变基因特点。该家系为两代4人,共有2例CMT1X患者。先证者12岁起病,先证者母亲40岁起病,两者均表现为进行性肢体无力、萎缩...分析X-连锁腓骨肌萎缩症1型(X-linked Charcot-Marie-Tooth disease type 1,CMT1X)一家系的临床表现、电生理与突变基因特点。该家系为两代4人,共有2例CMT1X患者。先证者12岁起病,先证者母亲40岁起病,两者均表现为进行性肢体无力、萎缩,行走不稳。神经电生理检查均提示:四肢多发感觉运动神经损害(轴索损害为主并脱髓鞘);多发肌肉呈神经源性损害。突变基因分析,先证者存在缝隙连接蛋白B1(gap junction protein Bata-1,GJB1)基因c.283 G>T(p.V95L)半合子突变,先证者母亲存在GJB1基因c.283 G>T(p.V95L),杂合突变。CMT1X是第二常见的腓骨肌萎缩症(Charcot-Marie-Tooth disease,CMT)类型,由GJB1基因突变引起,临床表现为进行性发展的周围神经病可合并中枢神经系统损害,基因检测有助诊断。展开更多
The mechanisms that regulate neural stem cell(NSC)lineage progression and maintain NSCs within diffe rent domains of the adult neural stem cell niche,the subventricular zone are not well defined.Quiescent NSCs are arr...The mechanisms that regulate neural stem cell(NSC)lineage progression and maintain NSCs within diffe rent domains of the adult neural stem cell niche,the subventricular zone are not well defined.Quiescent NSCs are arranged at the apical ventricular wall,while mitotically activated NSCs are found in the basal,vascular region of the subventricular zone.Here,we found that ADAM 10(a disintegrin and metalloproteinase 10)is essential in NSC association with the ventricular wall,and via this adhesion to the apical domain,ADAM10 regulates the switch from quiescent and undiffe rentiated NSC to an actively prolife rative and differentiating cell state.Processing of JAMC(junctional adhesion molecule C)by ADAM 10 increases Rap1 GAP activity.This molecular machinery promotes NSC transit from the apical to the basal compartment and subsequent lineage progression.Understanding the molecular mechanisms responsible for regulating the proper positioning of NSCs within the subventricular zone niche and lineage progression of NSCs could provide new targets for drug development to enhance the regenerative prope rties of neural tissue.展开更多
Background： Among patients with Charcot-Marie-Tooth disease （CMT）, the X-linked variant （CMTX） caused by gap junction protein beta 1 （GJB1） gene mutation is the second most frequent type, accounting for approxi...Background： Among patients with Charcot-Marie-Tooth disease （CMT）, the X-linked variant （CMTX） caused by gap junction protein beta 1 （GJB1） gene mutation is the second most frequent type, accounting for approximately 90% of all CMTX. More than 400 mutations have been identified in the GJB1 gene that encodes connexin 32 （CX32）. CX32 is thought to form gap junctions that promote the diffusion pathway between cells. GJB1 mutations interfere with the formation of the functional channel and impair the maintenance of peripheral myelin, and novel mutations are continually discovered. Methods： We included 79 unrelated patients clinically diagnosed with CMT at the Department of Neurology of the Chinese People＇s Liberation Army General Hospital from December 20, 2012, to December 31, 2015. Clinical examination, nerve conduction studies, and molecular and bioinformatics analyses were performed to identify patients with CMTX 1. Results： Nine GJBI mutations （c.283G〉A, c.77C〉T, c.643C〉T, c.515C〉T, c.191G〉A, c.610C〉T, c.490C〉T, c.491G〉A, and c.44G〉A） were discovered in nine patients. Median motor nerve conduction velocities of all nine patients were 〈 38 m/s, resembling CMT Type 1. Three novel mutations, c.643C〉T, c.191G〉A, and c.610C〉T, were revealed and bioinformatics analyses indicated high pathogenicity. Conclusions： The three novel missense mutations within the GJB1 gene broaden the mutational diversity ofCMT1X. Molecular analysis of family members and bioinformatics analyses of the afflicted patients confirmed the pathogenicity of these mutations.展开更多
The loss of endothelial connective integrity and endothelial barrier dysfunction can lead to increased vascular injury, which is related to the activation of endothelial inflammasomes. There are evidences that low con...The loss of endothelial connective integrity and endothelial barrier dysfunction can lead to increased vascular injury, which is related to the activation of endothelial inflammasomes. There are evidences that low concentrations of aspirin can effectively prevent cardiovascular diseases. We hypothesized that low-dose aspirin could ameliorate endothelial injury by inhibiting the activation of NLRP3 inflammasomes and ultimately prevent cardiovascular diseases. Microvascular endothelial cells were stimulated by lipopolysaccharide(2 μg/mL) and administrated by 0.1–2 mmol/L aspirin. The wild type mice were stimulated with LPS(100 μg/kg/day), and 1 h later treated with aspirin(12.5, 62.5, or125 mg/kg/day) and dexamethasone(0.0182 mg/kg/day) for 7 days. Plasma and heart were harvested for measurement of ELISA and immunofluorescence analyses. We found that aspirin could inhibit NLRP3 inflammasome formation and activation in vitro in dose-dependent manner and has correlation between the NLRP3 inflammasome and the ROS/TXNIP pathway. We also found that low-concentration aspirin could inhibit the formation and activation of NLRP3 inflammasome and restore the expression of theendothelial tight junction protein zonula occludens-1/2(ZO1/2). We assume that aspirin can ameliorate the endothelial layer dysfunction by suppressing the activation of NLRP3 inflammasome.展开更多
基金This research was supported by the Key Program，the National Natural Science Foundation of China
文摘Objective We performed experiments using Neuregulin-1β （NRG-1β） treatment to determine a mechanism for the protective role derived from its beneficial effects by remodeling gap junctions （GJs） during heart failure （HF）. Methods Rat models of I-IF were established by aortocaval fistula. Forty-eight rats were divided randomly into the HF （HF, n = 16）, NRG-1β trealanent （NRG, n = 16）, and sham operation （S, n = 16） group. The rats in the NRG group were administered NRG-1β （10 μg/kg per day） for 7 days via the tail vein, whereas the other groups were injected with the same doses of saline, Twelve weeks after operation, Connexin 43 （Cx43） expression in single myocytes obtained from the left ventricle was determined by immunocytochemistry. Total protein was extracted from frozen left ventricular tissues for immunoblotting assay, and the ultrastmcture of myocytes was observed by transmission electron microscopy. Results Compared with the HF group, the cardiac fimction of rats in the NRG group was markedly improved, irregular distribution and deceased Cx43 expression were relieved. The ultrastmcture of myocytes was seriously damaged in HF rats, and NRG-1β reduced these pathological damages. Conclusions Short-term NRG-1β treatment can rescue pump failure in experimental models of volume overload-induced HF, which is related to the recovery of GJs structure and the improvement of Cx43 expression.
基金supported by the Key Project of Guangzhou City,No.202206060002Science and Technology Project of Guangdong Province,No.2018B030332001Guangdong Provincial Pearl River Project,No.2021ZT09Y552 (all to GC)。
文摘Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.
基金National Institutes of Health(NIH)Grants R01 RMH099384(to AA)and T32GM008444(to NM)。
文摘The mechanisms that regulate neural stem cell(NSC)lineage progression and maintain NSCs within diffe rent domains of the adult neural stem cell niche,the subventricular zone are not well defined.Quiescent NSCs are arranged at the apical ventricular wall,while mitotically activated NSCs are found in the basal,vascular region of the subventricular zone.Here,we found that ADAM 10(a disintegrin and metalloproteinase 10)is essential in NSC association with the ventricular wall,and via this adhesion to the apical domain,ADAM10 regulates the switch from quiescent and undiffe rentiated NSC to an actively prolife rative and differentiating cell state.Processing of JAMC(junctional adhesion molecule C)by ADAM 10 increases Rap1 GAP activity.This molecular machinery promotes NSC transit from the apical to the basal compartment and subsequent lineage progression.Understanding the molecular mechanisms responsible for regulating the proper positioning of NSCs within the subventricular zone niche and lineage progression of NSCs could provide new targets for drug development to enhance the regenerative prope rties of neural tissue.
文摘Background： Among patients with Charcot-Marie-Tooth disease （CMT）, the X-linked variant （CMTX） caused by gap junction protein beta 1 （GJB1） gene mutation is the second most frequent type, accounting for approximately 90% of all CMTX. More than 400 mutations have been identified in the GJB1 gene that encodes connexin 32 （CX32）. CX32 is thought to form gap junctions that promote the diffusion pathway between cells. GJB1 mutations interfere with the formation of the functional channel and impair the maintenance of peripheral myelin, and novel mutations are continually discovered. Methods： We included 79 unrelated patients clinically diagnosed with CMT at the Department of Neurology of the Chinese People＇s Liberation Army General Hospital from December 20, 2012, to December 31, 2015. Clinical examination, nerve conduction studies, and molecular and bioinformatics analyses were performed to identify patients with CMTX 1. Results： Nine GJBI mutations （c.283G〉A, c.77C〉T, c.643C〉T, c.515C〉T, c.191G〉A, c.610C〉T, c.490C〉T, c.491G〉A, and c.44G〉A） were discovered in nine patients. Median motor nerve conduction velocities of all nine patients were 〈 38 m/s, resembling CMT Type 1. Three novel mutations, c.643C〉T, c.191G〉A, and c.610C〉T, were revealed and bioinformatics analyses indicated high pathogenicity. Conclusions： The three novel missense mutations within the GJB1 gene broaden the mutational diversity ofCMT1X. Molecular analysis of family members and bioinformatics analyses of the afflicted patients confirmed the pathogenicity of these mutations.
基金supported by the National Key Research and Development Program of China(No.2017YFC1700400)National Natural Science Foundation of China(Nos.81603587 and 81603668)+4 种基金Guangdong Natural Science Funds for Distinguished Young Scholar(No.2018B030306027,China)Science and Technology Development Plan of Guangdong Province(2017A020211016,China)Science&Technology Award for Young-Aged Talents of China Association of Traditional Chinese Medicine(No.CACM-2017-QNRC2-C12)the National Institutes of Health of USA(No.HL122769)Project of Guangzhou University of Chinese Medicine(No.A1-AFD018171Z11020,China)
文摘The loss of endothelial connective integrity and endothelial barrier dysfunction can lead to increased vascular injury, which is related to the activation of endothelial inflammasomes. There are evidences that low concentrations of aspirin can effectively prevent cardiovascular diseases. We hypothesized that low-dose aspirin could ameliorate endothelial injury by inhibiting the activation of NLRP3 inflammasomes and ultimately prevent cardiovascular diseases. Microvascular endothelial cells were stimulated by lipopolysaccharide(2 μg/mL) and administrated by 0.1–2 mmol/L aspirin. The wild type mice were stimulated with LPS(100 μg/kg/day), and 1 h later treated with aspirin(12.5, 62.5, or125 mg/kg/day) and dexamethasone(0.0182 mg/kg/day) for 7 days. Plasma and heart were harvested for measurement of ELISA and immunofluorescence analyses. We found that aspirin could inhibit NLRP3 inflammasome formation and activation in vitro in dose-dependent manner and has correlation between the NLRP3 inflammasome and the ROS/TXNIP pathway. We also found that low-concentration aspirin could inhibit the formation and activation of NLRP3 inflammasome and restore the expression of theendothelial tight junction protein zonula occludens-1/2(ZO1/2). We assume that aspirin can ameliorate the endothelial layer dysfunction by suppressing the activation of NLRP3 inflammasome.
