Hematopoiesis is crucial for organismal health,and Drosophila serves as an effective genetic model due to conserved regulatory mechanisms with vertebrates.In larvae,hematopoiesis primarily occurs in the lymph gland,wh...Hematopoiesis is crucial for organismal health,and Drosophila serves as an effective genetic model due to conserved regulatory mechanisms with vertebrates.In larvae,hematopoiesis primarily occurs in the lymph gland,which contains distinct zones,including the cortical zone,intermediate zone,medullary zone,and posterior signaling center(PSC).Rab1 is vital for membrane trafficking and maintaining the localization of cell adhesion molecules,yet its role in hematopoietic homeostasis is not fully understood.This study investigates the effects of Rab1 dysfunction on β-integrin trafficking within circulating hemocytes and lymph gland cells.Rab1 impairment disrupts the endosomal trafficking of β-integrin,leading to its abnormal localization on cell membranes,which promotes lamellocyte differentiation and alters progenitor dynamics in circulating hemocytes and lymph glands,respectively.We also show that the mislocalization of β-integrin is dependent on the adhesion protein DE-cadherin.The reduction of β-integrin at cell boundaries in PSC cells leads to fewer PSC cells and lamellocyte differentiation.Furthermore,Rab1 regulates the trafficking of β-integrin via the Q-SNARE protein Syntaxin 17(Syx17).Our findings indicate that Rab1 and Syx17 regulate distinct trafficking pathways for β-integrin in different hematopoietic compartments and maintain hematopoietic homeostasis of Drosophila.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
目的探讨Rab40家族在肝癌中的表达及临床意义。方法收集TIMER2.0数据库和The Human Protein Atlas数据库中肝癌数据集,分析Rab40家族在肝癌患者中的表达水平,并分析其表达与患者临床病理资料、肿瘤微环境免疫细胞浸润的关系;收集Kaplan-...目的探讨Rab40家族在肝癌中的表达及临床意义。方法收集TIMER2.0数据库和The Human Protein Atlas数据库中肝癌数据集,分析Rab40家族在肝癌患者中的表达水平,并分析其表达与患者临床病理资料、肿瘤微环境免疫细胞浸润的关系;收集Kaplan-Meier Plotter数据库中肝癌数据集,分析Rab40b和Rab40c的表达水平与肝癌患者预后的关系。结果肝癌组织中的Rab40a、Rab40al、Rab40b和Rab40c表达水平显著高于癌旁组织,差异具有统计学意义(P<0.05)。Rab40c高表达与肝癌患者TNM分期可能存在相关性(P=0.064)。Rab40b、Rab40c高表达肝癌患者的总生存期(OS)、无复发生存期(RFS)短于Rab40b、Rab40c低表达肝癌患者,差异具有统计学意义(P<0.05)。肝癌组织中Rab40b的表达水平与肿瘤微环境的B细胞和CD8^(+)T细胞无关(P>0.05),而与CD4^(+)T细胞、巨噬细胞、中性粒细胞和树突状细胞密切相关,差异具有统计学意义(P<0.05)。肝癌组织中Rab40c的表达水平与肿瘤微环境的B细胞、CD8^(+)T细胞、CD4^(+)T细胞、巨噬细胞、中性粒细胞和树突状细胞密切相关,差异具有统计学意义(P<0.05)。结论Rab40家族在肝癌中高表达,尤其是Rab40b和Rab40c,通过影响肿瘤微环境中的免疫细胞促进肝癌的发生、发展,可作为肝癌治疗和预后的潜在生物标志物。展开更多
基金supported by the National Natural Science Foundation of China(32170484 and 32300384)the Fundamental Research Funds for the Central Universities(2572022DQ07 and 2572020AW04).
文摘Hematopoiesis is crucial for organismal health,and Drosophila serves as an effective genetic model due to conserved regulatory mechanisms with vertebrates.In larvae,hematopoiesis primarily occurs in the lymph gland,which contains distinct zones,including the cortical zone,intermediate zone,medullary zone,and posterior signaling center(PSC).Rab1 is vital for membrane trafficking and maintaining the localization of cell adhesion molecules,yet its role in hematopoietic homeostasis is not fully understood.This study investigates the effects of Rab1 dysfunction on β-integrin trafficking within circulating hemocytes and lymph gland cells.Rab1 impairment disrupts the endosomal trafficking of β-integrin,leading to its abnormal localization on cell membranes,which promotes lamellocyte differentiation and alters progenitor dynamics in circulating hemocytes and lymph glands,respectively.We also show that the mislocalization of β-integrin is dependent on the adhesion protein DE-cadherin.The reduction of β-integrin at cell boundaries in PSC cells leads to fewer PSC cells and lamellocyte differentiation.Furthermore,Rab1 regulates the trafficking of β-integrin via the Q-SNARE protein Syntaxin 17(Syx17).Our findings indicate that Rab1 and Syx17 regulate distinct trafficking pathways for β-integrin in different hematopoietic compartments and maintain hematopoietic homeostasis of Drosophila.
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.
文摘目的探讨Rab40家族在肝癌中的表达及临床意义。方法收集TIMER2.0数据库和The Human Protein Atlas数据库中肝癌数据集,分析Rab40家族在肝癌患者中的表达水平,并分析其表达与患者临床病理资料、肿瘤微环境免疫细胞浸润的关系;收集Kaplan-Meier Plotter数据库中肝癌数据集,分析Rab40b和Rab40c的表达水平与肝癌患者预后的关系。结果肝癌组织中的Rab40a、Rab40al、Rab40b和Rab40c表达水平显著高于癌旁组织,差异具有统计学意义(P<0.05)。Rab40c高表达与肝癌患者TNM分期可能存在相关性(P=0.064)。Rab40b、Rab40c高表达肝癌患者的总生存期(OS)、无复发生存期(RFS)短于Rab40b、Rab40c低表达肝癌患者,差异具有统计学意义(P<0.05)。肝癌组织中Rab40b的表达水平与肿瘤微环境的B细胞和CD8^(+)T细胞无关(P>0.05),而与CD4^(+)T细胞、巨噬细胞、中性粒细胞和树突状细胞密切相关,差异具有统计学意义(P<0.05)。肝癌组织中Rab40c的表达水平与肿瘤微环境的B细胞、CD8^(+)T细胞、CD4^(+)T细胞、巨噬细胞、中性粒细胞和树突状细胞密切相关,差异具有统计学意义(P<0.05)。结论Rab40家族在肝癌中高表达,尤其是Rab40b和Rab40c,通过影响肿瘤微环境中的免疫细胞促进肝癌的发生、发展,可作为肝癌治疗和预后的潜在生物标志物。
