Membrane trafficking processes are presumably vital for axonal regeneration after injury, but mechanistic understanding in this regard has been sparse. A recent loss-of-function screen had been carried out for factors...Membrane trafficking processes are presumably vital for axonal regeneration after injury, but mechanistic understanding in this regard has been sparse. A recent loss-of-function screen had been carried out for factors important for axonal regeneration by cultured cortical neurons and the results suggested that the activity of a number of Rab GTPases might act to restrict axonal regeneration. A loss of Rab27b, in particular, is shown to enhance axonal regeneration in vitro, as well as in C. elegans and mouse central nervous system injury models in vivo. Possible mechanisms underlying this new finding, which has important academic and translational implication, are discussed.展开更多
目的探讨由RAB27A基因缺陷导致的格里塞利综合征2型(Griscelli syndrome type 2,GS2)的临床及免疫学特征。方法收集1家系2例GS2患儿组成的临床资料、生化检查及病理活检结果,采集头发显微镜检查,抽取外周静脉血进行免疫系统基因外显子...目的探讨由RAB27A基因缺陷导致的格里塞利综合征2型(Griscelli syndrome type 2,GS2)的临床及免疫学特征。方法收集1家系2例GS2患儿组成的临床资料、生化检查及病理活检结果,采集头发显微镜检查,抽取外周静脉血进行免疫系统基因外显子阵列测序,桑格测序验证患儿及父母RAB27A基因突变位点,采用蛋白印迹法检测外周血单个核细胞RAB27A蛋白表达水平,采用流式细胞术进行CTL细胞及NK细胞毒性功能检测,健康对照为正常同龄儿童。结果2例患者为亲兄妹,生后均表现毛发色素减退合,均以反复发热、反复呼吸道感染合并噬血细胞性淋巴组织细胞增生症(HLH)为主要临床表现,妹妹伴全身弥漫靶形损害样皮疹。2例患者头发内均有不规则黑色素团块堆积,妹妹皮损组织病理示表皮基底层黑色素细胞不规则分布,RAB27A基因5号外显子发生c.377 delC纯合移码突变,其父母为近亲结婚,均为携带者,2例患儿RAB27A蛋白表达均明显降低,NK细胞及CTL的细胞毒功能均受损。2例患儿均未接受化疗及造血干细胞移植(HSCT),先后因HLH死亡。结论GS2的确诊依赖临床表现及基因检测,免疫功能检测亦有助于诊断,同种异体造血干细胞移植是目前根治GS2的唯一方法。展开更多
BACKGROUND Alzheimer’s disease(AD)is a neurodegenerative condition characterized by oxidative stress and neuroinflammation.Tanshinone ⅡA(Tan-ⅡA),a bioactive compound isolated from Salvia miltiorrhiza plants,has sho...BACKGROUND Alzheimer’s disease(AD)is a neurodegenerative condition characterized by oxidative stress and neuroinflammation.Tanshinone ⅡA(Tan-ⅡA),a bioactive compound isolated from Salvia miltiorrhiza plants,has shown potential neuroprotective effects;however,the mechanisms underlying such a function remain unclear.AIM To investigate potential Tan-ⅡA neuroprotective effects in AD and to elucidate their underlying mechanisms.METHODS Hematoxylin and eosin staining was utilized to analyze structural brain tissue morphology.To assess changes in oxidative stress and neuroinflammation,we performed enzyme-linked immunosorbent assay and western blotting.Additionally,the effect of Tan-ⅡA on AD cell models was evaluated in vitro using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Genetic changes related to the long non-coding RNA(lncRNA)nuclear-enriched abundant transcript 1(NEAT1)/microRNA(miRNA,miR)-291a-3p/member RAS oncogene family Rab22a axis were assessed through reverse transcription quantitative polymerase chain reaction.RESULTS In vivo,Tan-ⅡA treatment improved neuronal morphology and attenuated oxidative stress and neuroinflammation in the brain tissue of AD mice.In vitro experiments showed that Tan-ⅡA dose-dependently ameliorated the amyloid-beta 1-42-induced reduction of neural stem cell viability,apoptosis,oxidative stress,and neuroinflammation.In this process,the lncRNA NEAT1-a potential therapeutic target-is highly expressed in AD mice and downregulated via Tan-ⅡA treatment.Mechanistically,NEAT1 promotes the transcription and translation of Rab22a via miR-291a-3p,which activates nuclear factor kappa-B(NF-κB)signaling,leading to activation of the pro-apoptotic B-cell lymphoma 2-associated X protein and inhibition of the anti-apoptotic B-cell lymphoma 2 protein,which exacerbates AD.Tan-ⅡA intervention effectively blocked this process by inhibiting the NEAT1/miR-291a-3p/Rab22a axis and NF-κB signaling.CONCLUSION This study demonstrates that Tan-ⅡA exerts neuroprotective effects in AD by modulating the NEAT1/miR-291a-3p/Rab22a/NF-κB signaling pathway,serving as a foundation for the development of innovative approaches for AD therapy.展开更多
In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting t...In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.展开更多
Rab5 is a GTPase protein that is involved in intracellular membrane trafficking. It functions by binding to various effector proteins and regulating cellular responses, including the formation of transport vesicles an...Rab5 is a GTPase protein that is involved in intracellular membrane trafficking. It functions by binding to various effector proteins and regulating cellular responses, including the formation of transport vesicles and their fusion with the cellular membrane. Rab5 has been reported to play an important role in the development of the zebrafish embryo;however, its role in axonal regeneration in the central nervous system remains unclear. In this study, we established a zebrafish Mauthner cell model of axonal injury using single-cell electroporation and two-photon axotomy techniques. We found that overexpression of Rab5 in single Mauthner cells promoted marked axonal regeneration and increased the number of intra-axonal transport vesicles. In contrast, treatment of zebrafish larvae with the Rab kinase inhibitor CID-1067700markedly inhibited axonal regeneration in Mauthner cells. We also found that Rab5 activated phosphatidylinositol 3-kinase(PI3K) during axonal repair of Mauthner cells and promoted the recovery of zebrafish locomotor function. Additionally, rapamycin, an inhibitor of the mechanistic target of rapamycin downstream of PI3K, markedly hindered axonal regeneration. These findings suggest that Rab5 promotes the axonal regeneration of injured zebrafish Mauthner cells by activating the PI3K signaling pathway.展开更多
基金supported by the National University of Singapore Graduate School for Integrative Sciences and Engineering(to BLT)
文摘Membrane trafficking processes are presumably vital for axonal regeneration after injury, but mechanistic understanding in this regard has been sparse. A recent loss-of-function screen had been carried out for factors important for axonal regeneration by cultured cortical neurons and the results suggested that the activity of a number of Rab GTPases might act to restrict axonal regeneration. A loss of Rab27b, in particular, is shown to enhance axonal regeneration in vitro, as well as in C. elegans and mouse central nervous system injury models in vivo. Possible mechanisms underlying this new finding, which has important academic and translational implication, are discussed.
文摘目的探讨由RAB27A基因缺陷导致的格里塞利综合征2型(Griscelli syndrome type 2,GS2)的临床及免疫学特征。方法收集1家系2例GS2患儿组成的临床资料、生化检查及病理活检结果,采集头发显微镜检查,抽取外周静脉血进行免疫系统基因外显子阵列测序,桑格测序验证患儿及父母RAB27A基因突变位点,采用蛋白印迹法检测外周血单个核细胞RAB27A蛋白表达水平,采用流式细胞术进行CTL细胞及NK细胞毒性功能检测,健康对照为正常同龄儿童。结果2例患者为亲兄妹,生后均表现毛发色素减退合,均以反复发热、反复呼吸道感染合并噬血细胞性淋巴组织细胞增生症(HLH)为主要临床表现,妹妹伴全身弥漫靶形损害样皮疹。2例患者头发内均有不规则黑色素团块堆积,妹妹皮损组织病理示表皮基底层黑色素细胞不规则分布,RAB27A基因5号外显子发生c.377 delC纯合移码突变,其父母为近亲结婚,均为携带者,2例患儿RAB27A蛋白表达均明显降低,NK细胞及CTL的细胞毒功能均受损。2例患儿均未接受化疗及造血干细胞移植(HSCT),先后因HLH死亡。结论GS2的确诊依赖临床表现及基因检测,免疫功能检测亦有助于诊断,同种异体造血干细胞移植是目前根治GS2的唯一方法。
基金Supported by 2020 Guangxi Zhuang Autonomous Region Health Care Commission Self-Financing Research Projects,No.Z202000962023 Guangxi University Young and Middle-Aged Teachers’Basic Research Ability Improvement Project,No.2023KY0091+1 种基金National Natural Science Foundation of China,No.82260241the Natural Science Foundation of Guangxi Province,No.2015GXNSFAA139171 and No.2020GXNSFAA259053.
文摘BACKGROUND Alzheimer’s disease(AD)is a neurodegenerative condition characterized by oxidative stress and neuroinflammation.Tanshinone ⅡA(Tan-ⅡA),a bioactive compound isolated from Salvia miltiorrhiza plants,has shown potential neuroprotective effects;however,the mechanisms underlying such a function remain unclear.AIM To investigate potential Tan-ⅡA neuroprotective effects in AD and to elucidate their underlying mechanisms.METHODS Hematoxylin and eosin staining was utilized to analyze structural brain tissue morphology.To assess changes in oxidative stress and neuroinflammation,we performed enzyme-linked immunosorbent assay and western blotting.Additionally,the effect of Tan-ⅡA on AD cell models was evaluated in vitro using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Genetic changes related to the long non-coding RNA(lncRNA)nuclear-enriched abundant transcript 1(NEAT1)/microRNA(miRNA,miR)-291a-3p/member RAS oncogene family Rab22a axis were assessed through reverse transcription quantitative polymerase chain reaction.RESULTS In vivo,Tan-ⅡA treatment improved neuronal morphology and attenuated oxidative stress and neuroinflammation in the brain tissue of AD mice.In vitro experiments showed that Tan-ⅡA dose-dependently ameliorated the amyloid-beta 1-42-induced reduction of neural stem cell viability,apoptosis,oxidative stress,and neuroinflammation.In this process,the lncRNA NEAT1-a potential therapeutic target-is highly expressed in AD mice and downregulated via Tan-ⅡA treatment.Mechanistically,NEAT1 promotes the transcription and translation of Rab22a via miR-291a-3p,which activates nuclear factor kappa-B(NF-κB)signaling,leading to activation of the pro-apoptotic B-cell lymphoma 2-associated X protein and inhibition of the anti-apoptotic B-cell lymphoma 2 protein,which exacerbates AD.Tan-ⅡA intervention effectively blocked this process by inhibiting the NEAT1/miR-291a-3p/Rab22a axis and NF-κB signaling.CONCLUSION This study demonstrates that Tan-ⅡA exerts neuroprotective effects in AD by modulating the NEAT1/miR-291a-3p/Rab22a/NF-κB signaling pathway,serving as a foundation for the development of innovative approaches for AD therapy.
基金supported by the Japan Society for the Promotion of Science KAKENHI(grant Nos.23K05678 to IM,19H05711 and 20H00466 to KS)the Joint Research Program of Institute for Molecular and Cellular Regulation,Gunma University(to KS)。
文摘In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.
基金supported by the Research Funds of the Center for Advanced Interdisciplinary Science and Biomedicine of IHM,No.QYZD20220002the National Natural Science Foundation of China,No.82071357a grant from the Ministry of Science and Technology of China,No.2019YFA0405600 (all to BH)。
文摘Rab5 is a GTPase protein that is involved in intracellular membrane trafficking. It functions by binding to various effector proteins and regulating cellular responses, including the formation of transport vesicles and their fusion with the cellular membrane. Rab5 has been reported to play an important role in the development of the zebrafish embryo;however, its role in axonal regeneration in the central nervous system remains unclear. In this study, we established a zebrafish Mauthner cell model of axonal injury using single-cell electroporation and two-photon axotomy techniques. We found that overexpression of Rab5 in single Mauthner cells promoted marked axonal regeneration and increased the number of intra-axonal transport vesicles. In contrast, treatment of zebrafish larvae with the Rab kinase inhibitor CID-1067700markedly inhibited axonal regeneration in Mauthner cells. We also found that Rab5 activated phosphatidylinositol 3-kinase(PI3K) during axonal repair of Mauthner cells and promoted the recovery of zebrafish locomotor function. Additionally, rapamycin, an inhibitor of the mechanistic target of rapamycin downstream of PI3K, markedly hindered axonal regeneration. These findings suggest that Rab5 promotes the axonal regeneration of injured zebrafish Mauthner cells by activating the PI3K signaling pathway.
