背景:骨的形成是一个动态的过程,破骨细胞和成骨细胞参与该动态过程。Semaphorin家族最早是作为轴突导向分子而被发现,其在许多不同组织里面表达并调节很多生理过程,近来更发现其在调节破骨细胞和成骨细胞方面发挥了重要作用。目的:总结...背景:骨的形成是一个动态的过程,破骨细胞和成骨细胞参与该动态过程。Semaphorin家族最早是作为轴突导向分子而被发现,其在许多不同组织里面表达并调节很多生理过程,近来更发现其在调节破骨细胞和成骨细胞方面发挥了重要作用。目的:总结Semaphorin家族各因子在骨动态平衡中发挥的作用。方法:应用计算机检索Pub Med和Web of science数据库中1993年6月至2014年1月关于Semaphorin家族各因子调控骨代谢的文章,以"semaphorin,sema"为检索词进行检索;排除与研究内容无关和内容重复的文章,保留48篇文章进行综述。结果与结论:semaphorins在骨的细胞生物学方面是一类新型的调控分子,研究显示semaphorins通过一些特殊的机制很活跃的参与了骨的重塑过程,semaphorin家族蛋白在骨自身动态平衡中很关键,这些发现给治疗骨质疏松、骨硬化症、关节假体旁骨溶解等骨病提供了一种新颖的方法及治疗靶点。展开更多
背景:轴突导向因子可能在α-突触核蛋白相关神经退行性疾病中发挥重要作用。目的:探讨轴突导向因子在α-突触核蛋白相关神经退行性疾病中的作用及机制。方法:由第一作者系统检索中国知网、万方数据库、PubMed、Nature、Embase、Web of S...背景:轴突导向因子可能在α-突触核蛋白相关神经退行性疾病中发挥重要作用。目的:探讨轴突导向因子在α-突触核蛋白相关神经退行性疾病中的作用及机制。方法:由第一作者系统检索中国知网、万方数据库、PubMed、Nature、Embase、Web of Sciense、JAMA、BMJ等数据库,中文检索词为“帕金森病,轴突导向因子,路易体痴呆,多系统衰竭,单纯性自主神经功能衰竭”,英文检索词为“Parkinson’s disease,axon guidance molecules,Netrin,Ephrin,Semaphorin,Slit,Dementia with Lewy Bodies,Multiple System Atrophy,Pure Autonomic Failure”,全面收集并整理近年来有关轴突导向因子与α-突触核蛋白相关神经退行性疾病的文献,最终纳入89篇文献进行综述分析。结果与结论:轴突导向因子蛋白家族包括Netrins、Ephrins、Semaphorins和Slits。Netrins通过影响肠道因子、依赖DCC受体调节多巴胺能神经元活力,进而影响神经退行性疾病进程。在Ephrins家族中,EphrinA/EphA参与介导神经元再生信号,EphA1借CXC趋化因子配体12/CXC趋化因子受体4通路调节炎症与神经病理,影响疾病发展。Semaphorins家族中的Semaphorins-3通过引导多巴胺能神经元轴突从黑质向纹状体生长,进而改善神经退行性疾病的行为学症状。在多巴胺能神经元轴突传导通路上,Slits经Slit/Robo等信号协作调控轴突定位与寻路过程,确保神经元信号传导路径的准确性,对神经元连接的维持与修复具有重要意义。展开更多
Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)iso...Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic CEC-sEVs.In the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector.Small EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a control.Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs.An array of behavior assays was used to measure neurological function.Compared with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological outcomes.In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth.Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone.Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs.Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes.Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignant tumor with a poor prognosis,which is often associated with chronic hepatitis B virus infection in China.Our previous study has shown that long non-codin...BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignant tumor with a poor prognosis,which is often associated with chronic hepatitis B virus infection in China.Our previous study has shown that long non-coding RNA semaphorin 6Aantisense RNA 1(SEMA6A-AS1)was significantly downregulated in hepatitis B virus-related HCC and associated with poor prognosis.AIM To explore the underlying mechanism of SEMA6A-AS1 in HCC progression.METHODS The expression levels of SEMA6A-AS1 and SEMA6A were detected using quantitative polymerase chain reaction,immunohistochemistry and Western blot.A growth curve,colony formation,wound-healing and transwell(with or without Matrigel)assays were respectively performed to assess the proliferation,migration and invasion abilities of HCC cells.Cell cycle and apoptosis assays were performed by flow cytometry.To investigate the potential mechanism underpinning SEMA6A-AS1,we utilized tagged RNA affinity purification,dual luciferase reporter assay and immunofluorescence.RESULTS Downregulation of SEMA6A-AS1 in HCC was negatively correlated with SEMA6A protein expression.SEMA6A was upregulated in HCC and correlated with high alpha-fetoprotein level,high Edmondson-Steiner grade and poor prognosis.SEMA6A-AS1 significantly inhibited the proliferation,migration and invasion of HCC cells by combining with SEMA6A mRNA and promoting its degradation.SEMA6A protein promoted the proliferation,migration and invasion of HCC cells by regulating the actin cytoskeleton.CONCLUSION Our findings suggest that SEMA6A-AS1 can inhibit HCC progression through decreasing SEMA6A expression by promoting its mRNA degradation.SEMA6A-AS1 may be a prognostic biomarker and therapeutic target for HCC.展开更多
The nervous system processes a vast amount of information,performing computations that underlie perception,cognition,and behavior.During development,neuronal guidance genes,which encode extracellular cues,their recept...The nervous system processes a vast amount of information,performing computations that underlie perception,cognition,and behavior.During development,neuronal guidance genes,which encode extracellular cues,their receptors,and downstream signal transducers,organize neural wiring to generate the complex architecture of the nervous system.It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system.This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system.Supporting this view,these pathways continue to regulate synaptic connectivity,plasticity,and remodeling,and overall brain homeostasis throughout adulthood.Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders.Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified,emerging evidence points to several common themes,including dysfunction in neurons,microglia,astrocytes,and endothelial cells,along with dysregulation of neuron-microglia-astrocyte,neuroimmune,and neurovascular interactions.In this review,we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions.For instance,recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation.We discuss the challenges ahead,along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases.Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions.Specifically,we examine the crosstalk between neuronal guidance signaling and TREM2,a master regulator of microglial function,in the context of pathogenic protein aggregates.It is well-established that age is a major risk factor for neurodegeneration.Future research should address how aging and neuronal guidance signaling interact to influence an individual’s susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.展开更多
Semaphorins were originally identified as axon guidance factors involved in the development of the neuronal system. However, accumulating evidence indicates that several members of semaphorins, so-called ＇immune sema...Semaphorins were originally identified as axon guidance factors involved in the development of the neuronal system. However, accumulating evidence indicates that several members of semaphorins, so-called ＇immune semaphorins＇, are crucially involved in various phases of immune responses. These semaphorins regulate both immune cell interactions and immune cell trafficking during physiological and pathological immune responses. Here, we review the following two functional aspects of semaphorins and their receptors in immune responses： their functions in cell-cell interactions and their involvement in immune cell trafficking.展开更多
Plexins and semaphorins are a large family of proteins that are involved in cell movement and response.The importance of plexins and semaphorins has been emphasized by their discovery in many organ systems including t...Plexins and semaphorins are a large family of proteins that are involved in cell movement and response.The importance of plexins and semaphorins has been emphasized by their discovery in many organ systems including the nervous(Nkyimbeng-Takwi and Chapoval,2011;McCormick and Leipzig,2012;Yaron and Sprinzak,2012),epithelial(Miao et al.,1999;Fujii et al.,2002),and immune systems(Takamatsu and Kumanogoh,2012)as well as diverse cell processes including angiogenesis(Serini et al.,2009;Sakurai et al.,2012),embryogenesis(Perala et al.,2012),and cancer(Potiron et al.,2009;Micucci et al.,2010).Plexins and semaphorins are transmembrane proteins that share a conserved extracellular semaphorin do-main(Hota and Buck,2012).The plexins and sema-phorins are divided into four and eight subfamilies respectively based on their structural homology.Semaphorins are relatively small proteins containing the extracellular semaphorin domain and short intra-cellular tails.Plexins contain the semaphorin domain and long intracellular tails(Hota and Buck,2012).The majority of plexin and semaphorin research has fo-cused on the nervous system,particularly the devel-oping nervous system,where these proteins are found to mediate many common neuronal cell processes including cell movement,cytoskeletal rearrangement,and signal transduction(Choi et al.,2008;Takamatsu et al.,2010).Their roles in the immune system are the focus of this review.展开更多
Gorham-Stout disease(GSD)is a sporadic chronic disease characterized by progressive bone dissolution,absorption,and disappearance along with lymphatic vessel infiltration in bone-marrow cavities.Although the osteolyti...Gorham-Stout disease(GSD)is a sporadic chronic disease characterized by progressive bone dissolution,absorption,and disappearance along with lymphatic vessel infiltration in bone-marrow cavities.Although the osteolytic mechanism of GSD has been widely studied,the cause of lymphatic hyperplasia in GSD is rarely investigated.In this study,by comparing the RNA expression profile of osteoclasts(OCs)with that of OC precursors(OCPs)by RNA sequencing,we identified a new factor,semaphorin 3A(Sema3A),which is an osteoprotective factor involved in the lymphatic expansion of GSD.Compared to OCPs,OCs enhanced the growth,migration,and tube formation of lymphatic endothelial cells(LECs),in which the expression of Sema3A is low compared to that in OCPs.In the presence of recombinant Sema3A,the growth,migration,and tube formation of LECs were inhibited,further confirming the inhibitory effect of Sema3A on LECs in vitro.Using an LEC-induced GSD mouse model,the effect of Sema3A was examined by injecting lentivirus-expressing Sema3A into the tibiae in vivo.We found that the overexpression of Sema3A in tibiae suppressed the expansion of LECs and alleviated bone loss,whereas the injection of lentivirus expressing Sema3A short hairpin RNA(shRNA)into the tibiae caused GSD-like phenotypes.Histological staining further demonstrated that OCs decreased and osteocalcin increased after Sema3A lentiviral treatment,compared with the control.Based on the above results,we propose that reduced Sema3A in OCs is one of the mechanisms contributing to the pathogeneses of GSD and that expressing Sema3A represents a new approach for the treatment of GSD.展开更多
文摘背景:骨的形成是一个动态的过程,破骨细胞和成骨细胞参与该动态过程。Semaphorin家族最早是作为轴突导向分子而被发现,其在许多不同组织里面表达并调节很多生理过程,近来更发现其在调节破骨细胞和成骨细胞方面发挥了重要作用。目的:总结Semaphorin家族各因子在骨动态平衡中发挥的作用。方法:应用计算机检索Pub Med和Web of science数据库中1993年6月至2014年1月关于Semaphorin家族各因子调控骨代谢的文章,以"semaphorin,sema"为检索词进行检索;排除与研究内容无关和内容重复的文章,保留48篇文章进行综述。结果与结论:semaphorins在骨的细胞生物学方面是一类新型的调控分子,研究显示semaphorins通过一些特殊的机制很活跃的参与了骨的重塑过程,semaphorin家族蛋白在骨自身动态平衡中很关键,这些发现给治疗骨质疏松、骨硬化症、关节假体旁骨溶解等骨病提供了一种新颖的方法及治疗靶点。
文摘背景:轴突导向因子可能在α-突触核蛋白相关神经退行性疾病中发挥重要作用。目的:探讨轴突导向因子在α-突触核蛋白相关神经退行性疾病中的作用及机制。方法:由第一作者系统检索中国知网、万方数据库、PubMed、Nature、Embase、Web of Sciense、JAMA、BMJ等数据库,中文检索词为“帕金森病,轴突导向因子,路易体痴呆,多系统衰竭,单纯性自主神经功能衰竭”,英文检索词为“Parkinson’s disease,axon guidance molecules,Netrin,Ephrin,Semaphorin,Slit,Dementia with Lewy Bodies,Multiple System Atrophy,Pure Autonomic Failure”,全面收集并整理近年来有关轴突导向因子与α-突触核蛋白相关神经退行性疾病的文献,最终纳入89篇文献进行综述分析。结果与结论:轴突导向因子蛋白家族包括Netrins、Ephrins、Semaphorins和Slits。Netrins通过影响肠道因子、依赖DCC受体调节多巴胺能神经元活力,进而影响神经退行性疾病进程。在Ephrins家族中,EphrinA/EphA参与介导神经元再生信号,EphA1借CXC趋化因子配体12/CXC趋化因子受体4通路调节炎症与神经病理,影响疾病发展。Semaphorins家族中的Semaphorins-3通过引导多巴胺能神经元轴突从黑质向纹状体生长,进而改善神经退行性疾病的行为学症状。在多巴胺能神经元轴突传导通路上,Slits经Slit/Robo等信号协作调控轴突定位与寻路过程,确保神经元信号传导路径的准确性,对神经元连接的维持与修复具有重要意义。
基金supported by the NIH grants,R01 NS111801(to ZGZ)American Heart Association 16SDG29860003(to YZ)。
文摘Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic CEC-sEVs.In the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector.Small EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a control.Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs.An array of behavior assays was used to measure neurological function.Compared with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological outcomes.In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth.Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone.Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs.Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes.Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.
基金Supported by Natural Science Foundation of Hunan Province,No.2021JJ41048 and No.S2019JJQNJJ2012and Changsha Natural Science Foundation,No.kq2208400.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignant tumor with a poor prognosis,which is often associated with chronic hepatitis B virus infection in China.Our previous study has shown that long non-coding RNA semaphorin 6Aantisense RNA 1(SEMA6A-AS1)was significantly downregulated in hepatitis B virus-related HCC and associated with poor prognosis.AIM To explore the underlying mechanism of SEMA6A-AS1 in HCC progression.METHODS The expression levels of SEMA6A-AS1 and SEMA6A were detected using quantitative polymerase chain reaction,immunohistochemistry and Western blot.A growth curve,colony formation,wound-healing and transwell(with or without Matrigel)assays were respectively performed to assess the proliferation,migration and invasion abilities of HCC cells.Cell cycle and apoptosis assays were performed by flow cytometry.To investigate the potential mechanism underpinning SEMA6A-AS1,we utilized tagged RNA affinity purification,dual luciferase reporter assay and immunofluorescence.RESULTS Downregulation of SEMA6A-AS1 in HCC was negatively correlated with SEMA6A protein expression.SEMA6A was upregulated in HCC and correlated with high alpha-fetoprotein level,high Edmondson-Steiner grade and poor prognosis.SEMA6A-AS1 significantly inhibited the proliferation,migration and invasion of HCC cells by combining with SEMA6A mRNA and promoting its degradation.SEMA6A protein promoted the proliferation,migration and invasion of HCC cells by regulating the actin cytoskeleton.CONCLUSION Our findings suggest that SEMA6A-AS1 can inhibit HCC progression through decreasing SEMA6A expression by promoting its mRNA degradation.SEMA6A-AS1 may be a prognostic biomarker and therapeutic target for HCC.
基金supported by JSPS(KAKENHI:21K06205,23K06937,24K23419)AMED(to JYK,SaY,TM,SiY,YT,and NH)JYW had long been supported by the NIH.
文摘The nervous system processes a vast amount of information,performing computations that underlie perception,cognition,and behavior.During development,neuronal guidance genes,which encode extracellular cues,their receptors,and downstream signal transducers,organize neural wiring to generate the complex architecture of the nervous system.It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system.This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system.Supporting this view,these pathways continue to regulate synaptic connectivity,plasticity,and remodeling,and overall brain homeostasis throughout adulthood.Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders.Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified,emerging evidence points to several common themes,including dysfunction in neurons,microglia,astrocytes,and endothelial cells,along with dysregulation of neuron-microglia-astrocyte,neuroimmune,and neurovascular interactions.In this review,we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions.For instance,recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation.We discuss the challenges ahead,along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases.Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions.Specifically,we examine the crosstalk between neuronal guidance signaling and TREM2,a master regulator of microglial function,in the context of pathogenic protein aggregates.It is well-established that age is a major risk factor for neurodegeneration.Future research should address how aging and neuronal guidance signaling interact to influence an individual’s susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.
文摘Semaphorins were originally identified as axon guidance factors involved in the development of the neuronal system. However, accumulating evidence indicates that several members of semaphorins, so-called ＇immune semaphorins＇, are crucially involved in various phases of immune responses. These semaphorins regulate both immune cell interactions and immune cell trafficking during physiological and pathological immune responses. Here, we review the following two functional aspects of semaphorins and their receptors in immune responses： their functions in cell-cell interactions and their involvement in immune cell trafficking.
文摘Plexins and semaphorins are a large family of proteins that are involved in cell movement and response.The importance of plexins and semaphorins has been emphasized by their discovery in many organ systems including the nervous(Nkyimbeng-Takwi and Chapoval,2011;McCormick and Leipzig,2012;Yaron and Sprinzak,2012),epithelial(Miao et al.,1999;Fujii et al.,2002),and immune systems(Takamatsu and Kumanogoh,2012)as well as diverse cell processes including angiogenesis(Serini et al.,2009;Sakurai et al.,2012),embryogenesis(Perala et al.,2012),and cancer(Potiron et al.,2009;Micucci et al.,2010).Plexins and semaphorins are transmembrane proteins that share a conserved extracellular semaphorin do-main(Hota and Buck,2012).The plexins and sema-phorins are divided into four and eight subfamilies respectively based on their structural homology.Semaphorins are relatively small proteins containing the extracellular semaphorin domain and short intra-cellular tails.Plexins contain the semaphorin domain and long intracellular tails(Hota and Buck,2012).The majority of plexin and semaphorin research has fo-cused on the nervous system,particularly the devel-oping nervous system,where these proteins are found to mediate many common neuronal cell processes including cell movement,cytoskeletal rearrangement,and signal transduction(Choi et al.,2008;Takamatsu et al.,2010).Their roles in the immune system are the focus of this review.
基金supported by the National Natural Science Foundation of China(No.81974321)the Discipline Innovation and Talent Introduction Program to Universities from Ministry of Education of China(Project 111)+3 种基金the Tackling Project for Science and Technology of Xinxiang City(No.GG2019003)the Natural Science Foundation of Henan Province of China(No.212300410173)the State Administration of Traditional Chinese Medicine Young Qi Huang Scholar,and the Innovation Team Project of Scientific Research of Traditional Chinese Medicine of Shanghai Health Committee(No.2022CX001)China.
文摘Gorham-Stout disease(GSD)is a sporadic chronic disease characterized by progressive bone dissolution,absorption,and disappearance along with lymphatic vessel infiltration in bone-marrow cavities.Although the osteolytic mechanism of GSD has been widely studied,the cause of lymphatic hyperplasia in GSD is rarely investigated.In this study,by comparing the RNA expression profile of osteoclasts(OCs)with that of OC precursors(OCPs)by RNA sequencing,we identified a new factor,semaphorin 3A(Sema3A),which is an osteoprotective factor involved in the lymphatic expansion of GSD.Compared to OCPs,OCs enhanced the growth,migration,and tube formation of lymphatic endothelial cells(LECs),in which the expression of Sema3A is low compared to that in OCPs.In the presence of recombinant Sema3A,the growth,migration,and tube formation of LECs were inhibited,further confirming the inhibitory effect of Sema3A on LECs in vitro.Using an LEC-induced GSD mouse model,the effect of Sema3A was examined by injecting lentivirus-expressing Sema3A into the tibiae in vivo.We found that the overexpression of Sema3A in tibiae suppressed the expansion of LECs and alleviated bone loss,whereas the injection of lentivirus expressing Sema3A short hairpin RNA(shRNA)into the tibiae caused GSD-like phenotypes.Histological staining further demonstrated that OCs decreased and osteocalcin increased after Sema3A lentiviral treatment,compared with the control.Based on the above results,we propose that reduced Sema3A in OCs is one of the mechanisms contributing to the pathogeneses of GSD and that expressing Sema3A represents a new approach for the treatment of GSD.
