R-spondin2(Rspo2)是蛋白质家族RSPOs成员之一,其可以通过富含亮氨酸重复序列的G蛋白偶联受体4/5(leucine-rich repeat-containing G protein-coupled receptor 4/5,LGR4/5)、细胞表面跨膜E3泛素连接酶ZNRF3/RNF43(zinc and ring finger...R-spondin2(Rspo2)是蛋白质家族RSPOs成员之一,其可以通过富含亮氨酸重复序列的G蛋白偶联受体4/5(leucine-rich repeat-containing G protein-coupled receptor 4/5,LGR4/5)、细胞表面跨膜E3泛素连接酶ZNRF3/RNF43(zinc and ring finger 3/ring finger protein 43)、硫酸乙酰肝素蛋白聚糖(heparan sulfate proteoglycans,HSPGs)和含GTP酶激活蛋白质1的IQ基序(IQ motif-containing GTPase-activating protein 1,IQGAP1)来调控Wnt/β连环蛋白(catenin)信号通路,Wnt/β-catenin信号通路是目前研究最广泛且与基础骨生物学直接相关的信号通路,该通路中任何一环节出现问题都可能对骨的调控产生影响。近年来研究发现,Rspo2可以通过Wnt/β-catenin对成骨细胞(osteoblast,OB)、破骨细胞(osteoclast,OC)和软骨细胞产生作用,并参与一些骨骼疾病如脊柱后纵韧带骨化(ossification of the posterior longitudinal ligament,OPLL)、骨关节炎(osteoarthritis,OA)和类风湿性关节炎(rheumatoid arthritis,RA)的发生发展,因此对Rspo2的研究可能会成为骨相关疾病新的治疗方向。本文结合最新研究进展,就Rspo2的结构和主要功能、Rspo2调控Wnt/β-catenin信号通路的相关机制及其对骨骼系统的影响作一综述,以期为骨相关疾病的防治提供新的思路和途径。展开更多
The R-spondin family of proteins are Wnt agonists, and the complete embryonic disruption of Rspo2 results in skeletal developmental defects that recapitulate the phenotype observed with Lrp5/6 deficiency. Previous wor...The R-spondin family of proteins are Wnt agonists, and the complete embryonic disruption of Rspo2 results in skeletal developmental defects that recapitulate the phenotype observed with Lrp5/6 deficiency. Previous work has shown that R-spondin-2(Rspo2, RSPO2) is both highly expressed in Wnt-stimulated pre-osteoblasts and its overexpression induces osteoblast differentiation in the same cells, supporting its putative role as a positive autocrine regulator of osteoblastogenesis. However, the role of Rspo2 in regulating osteoblastogenesis and bone formation in postnatal bone has not been explored. Here we show that limb-bud progenitor cells from Rspo2 knockout mice undergo reduced mineralization during osteoblastogenesis in vitro and have a corresponding alteration in their osteogenic gene expression profile. We also generated the first Rspo2 conditional knockout(Rspo2 floxed) mouse and disrupted Rspo2 expression in osteoblast-lineage cells by crossing to the Osteocalcin-Cre mouse line(OcnCre + Rspo2 ^(f/f)). Ocn-Cre + Rspo2 f/fmale and female mice at 1, 3, and 6 months were examined. Ocn-Cre + Rspo2 f/fmice are decreased in overall body size compared to their control littermates and have decreased bone mass. Histomorphometric analysis of1-month-old mice revealed a similar number of osteoblasts and mineralizing surface per bone surface with a simultaneous decrease in mineral apposition and bone formation rates. Consistent with this observation, serum osteocalcin in 3-month-old Ocn-Cre +Rspo2 f/fwas reduced, and bone marrow-mesenchymal stem cells from Ocn-Cre + Rspo2 f/fmice undergo less mineralization in vitro.Finally, gene expression analysis and immunohistochemistry of mature bone shows reduced beta-catenin signaling in Ocn-Cre +Rspo2 f/f. Overall, RSPO2 reduces osteoblastogenesis and mineralization, leading to reduced bone mass.展开更多
BACKGROUND Colorectal cancer(CRC)is the second leading cause of cancer-related death,lar-gely due to limited treatment options in advanced stages.Genomic alterations in advanced CRC(aCRC)are complex and not fully char...BACKGROUND Colorectal cancer(CRC)is the second leading cause of cancer-related death,lar-gely due to limited treatment options in advanced stages.Genomic alterations in advanced CRC(aCRC)are complex and not fully characterized,with only 30%of patients benefiting from targeted therapies.AIM To investigate the molecular heterogeneity of primary aCRC in order to identify clinically relevant genomic alterations.METHODS We conducted a retrospective molecular analysis of 73 consecutive patients with histologically confirmed primary aCRC(stage pT4a-b).All molecular findings were correlated with available clinicopathological data.In addition,we performed RESULTS Genetic abnormalities identified in primary tumors were most frequently mutations in tumor protein p53(58%of cases),Kirsten rat sarcoma viral oncogene homolog(52%),phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha(25%),B-Raf kinase(11%)and fibroblast growth factor receptor 3(8%),as well as R-spondin 3(RSPO3)fusions(8%).Alterations in the tumor protein p53 and neuroblastoma RAS viral oncogene homolog genes were predominantly observed in tumors from the left colon,whereas B-Raf kinase mutations and RSPO3 fusions were more frequently detected in the right or transverse colon.We also show a strong association between the presence of RSPO3 rearrangements and patients with small tumors,normal carcinoembryonic antigen levels,and microsatellite stable tumors.Furthermore,aCRC patients with protein tyrosine phosphatase receptor type k::RSPO3 fusions exhibited a higher mortality rate.Elevated RSPO3 gene expression levels were also significantly correlated with poorer OS across two large,independent CRC cohorts.CONCLUSION This study identifies a relatively high incidence of RSPO3 rearrangements in aCRC and a strong association with clinical features.Furthermore,we find that RSPO3 fusions are associated with poorer OS.展开更多
文摘R-spondin2(Rspo2)是蛋白质家族RSPOs成员之一,其可以通过富含亮氨酸重复序列的G蛋白偶联受体4/5(leucine-rich repeat-containing G protein-coupled receptor 4/5,LGR4/5)、细胞表面跨膜E3泛素连接酶ZNRF3/RNF43(zinc and ring finger 3/ring finger protein 43)、硫酸乙酰肝素蛋白聚糖(heparan sulfate proteoglycans,HSPGs)和含GTP酶激活蛋白质1的IQ基序(IQ motif-containing GTPase-activating protein 1,IQGAP1)来调控Wnt/β连环蛋白(catenin)信号通路,Wnt/β-catenin信号通路是目前研究最广泛且与基础骨生物学直接相关的信号通路,该通路中任何一环节出现问题都可能对骨的调控产生影响。近年来研究发现,Rspo2可以通过Wnt/β-catenin对成骨细胞(osteoblast,OB)、破骨细胞(osteoclast,OC)和软骨细胞产生作用,并参与一些骨骼疾病如脊柱后纵韧带骨化(ossification of the posterior longitudinal ligament,OPLL)、骨关节炎(osteoarthritis,OA)和类风湿性关节炎(rheumatoid arthritis,RA)的发生发展,因此对Rspo2的研究可能会成为骨相关疾病新的治疗方向。本文结合最新研究进展,就Rspo2的结构和主要功能、Rspo2调控Wnt/β-catenin信号通路的相关机制及其对骨骼系统的影响作一综述,以期为骨相关疾病的防治提供新的思路和途径。
基金supported by the National Institutes of Health (NIH) National Institute of Arthritis and Musculoskeletal Diseases (NIAMS)funding of the University of Pennsylvania Center for Musculoskeletal Disorders (PCMD) (P30AR069619)the University of Michigan Integrative Musculoskeletal Health Core Center (P30AR069620)+1 种基金supported by NIH NIAMS R01AR066028supported by NIH NIAMS F31AR065858
文摘The R-spondin family of proteins are Wnt agonists, and the complete embryonic disruption of Rspo2 results in skeletal developmental defects that recapitulate the phenotype observed with Lrp5/6 deficiency. Previous work has shown that R-spondin-2(Rspo2, RSPO2) is both highly expressed in Wnt-stimulated pre-osteoblasts and its overexpression induces osteoblast differentiation in the same cells, supporting its putative role as a positive autocrine regulator of osteoblastogenesis. However, the role of Rspo2 in regulating osteoblastogenesis and bone formation in postnatal bone has not been explored. Here we show that limb-bud progenitor cells from Rspo2 knockout mice undergo reduced mineralization during osteoblastogenesis in vitro and have a corresponding alteration in their osteogenic gene expression profile. We also generated the first Rspo2 conditional knockout(Rspo2 floxed) mouse and disrupted Rspo2 expression in osteoblast-lineage cells by crossing to the Osteocalcin-Cre mouse line(OcnCre + Rspo2 ^(f/f)). Ocn-Cre + Rspo2 f/fmale and female mice at 1, 3, and 6 months were examined. Ocn-Cre + Rspo2 f/fmice are decreased in overall body size compared to their control littermates and have decreased bone mass. Histomorphometric analysis of1-month-old mice revealed a similar number of osteoblasts and mineralizing surface per bone surface with a simultaneous decrease in mineral apposition and bone formation rates. Consistent with this observation, serum osteocalcin in 3-month-old Ocn-Cre +Rspo2 f/fwas reduced, and bone marrow-mesenchymal stem cells from Ocn-Cre + Rspo2 f/fmice undergo less mineralization in vitro.Finally, gene expression analysis and immunohistochemistry of mature bone shows reduced beta-catenin signaling in Ocn-Cre +Rspo2 f/f. Overall, RSPO2 reduces osteoblastogenesis and mineralization, leading to reduced bone mass.
文摘R-spondins是包含凝血酶敏感蛋白1型重复序列[thrombospondin type 1 repeat(TSR-1)-containing proteins]的结构域家族,由四种分泌糖蛋白R-spondin 1-4组成。R-spondins通过富含亮氨酸的G蛋白偶联受体4/5/6(leucine-rish repeat-containing G-protein coupled receptor 4/5/6,LGR4/5/6)、细胞表面跨膜E3泛素连接酶ZNRF3[(zinc and ring finger 3)/RNF43(ring finger protein 43)]、硫酸乙酰肝素蛋白多糖(heparan sulfate proteoglycans,HSPGs)、包含GTPase激活蛋白1(IQ motif containing GTPase-activating protein 1,IQGAP1)来增强WNT/β-catenin信号通路,进而在人类胚胎发育、组织和器官稳定、干细胞自我更新等方面发挥作用。近年来研究发现R-spondins参与胚胎骨发育、成体骨形成和骨关节疾病的发生发展,对R-spondins的研究可能成为骨代谢疾病新的治疗方向。本文将对R-spondins增强WNT/β-catenin信号通路的相关机制及其对胚胎骨发育、成体骨形成、骨质疏松和骨关节炎相关疾病的影响做一综述。
文摘目的探讨R-spondin3(RSPO3)在乳腺癌中的表达及预后价值。方法应用TIMER、癌症基因组图谱(The Cancer Genome Atlas,TCGA)、基因表达谱数据动态分析(gene expression profilling in-teractive analysis 2,GEPIA2)、人类蛋白质表达图谱(Human Protein Atlas,HPA)等数据库分析RSPO3在乳腺癌组织和癌周正常组织中的差异表达,并分析其表达水平与乳腺癌病理学参数之间的相关性;GEPIA2数据库探讨RSPO3转录本在乳腺癌中的表达及其结构特征;Kaplan-Meier Plotter绘制RSPO3与乳腺癌患者的预后生存曲线;运用基因本体论(gene ontology,GO)和京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)等对其进行基因功能富集分析和代谢通路分析;应用TIMER数据库分析RSPO3的表达水平与肿瘤微环境中免疫细胞浸润的相关性。结果RSPO3在乳腺癌中呈低表达,且其表达水平与乳腺癌患者的年龄、肿瘤最大径、分子分型相关,在乳腺癌中低表达的RSPO3与患者的预后不良相关;GO功能富集分析显示,RSPO3相互作用的基因主要富集于免疫细胞及其受体等参与的生物学过程;免疫细胞浸润分析结果显示,RSPO3在乳腺癌组织中的表达水平与CD8^(+)T细胞、CD4^(+)T细胞、CD4^(+)记忆T细胞、巨噬细胞、B细胞等的浸润水平呈正相关,而与调节性T细胞(Treg细胞)的浸润水平呈负相关;KEGG代谢通路分析显示,RSPO3可能参与Wnt/β-catenin通路。结论在乳腺癌中低表达的RSPO3与患者的不良预后相关,其可能通过抑制免疫细胞浸润及活化Wnt/β-catenin通路参与乳腺癌的进展。
文摘BACKGROUND Colorectal cancer(CRC)is the second leading cause of cancer-related death,lar-gely due to limited treatment options in advanced stages.Genomic alterations in advanced CRC(aCRC)are complex and not fully characterized,with only 30%of patients benefiting from targeted therapies.AIM To investigate the molecular heterogeneity of primary aCRC in order to identify clinically relevant genomic alterations.METHODS We conducted a retrospective molecular analysis of 73 consecutive patients with histologically confirmed primary aCRC(stage pT4a-b).All molecular findings were correlated with available clinicopathological data.In addition,we performed RESULTS Genetic abnormalities identified in primary tumors were most frequently mutations in tumor protein p53(58%of cases),Kirsten rat sarcoma viral oncogene homolog(52%),phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha(25%),B-Raf kinase(11%)and fibroblast growth factor receptor 3(8%),as well as R-spondin 3(RSPO3)fusions(8%).Alterations in the tumor protein p53 and neuroblastoma RAS viral oncogene homolog genes were predominantly observed in tumors from the left colon,whereas B-Raf kinase mutations and RSPO3 fusions were more frequently detected in the right or transverse colon.We also show a strong association between the presence of RSPO3 rearrangements and patients with small tumors,normal carcinoembryonic antigen levels,and microsatellite stable tumors.Furthermore,aCRC patients with protein tyrosine phosphatase receptor type k::RSPO3 fusions exhibited a higher mortality rate.Elevated RSPO3 gene expression levels were also significantly correlated with poorer OS across two large,independent CRC cohorts.CONCLUSION This study identifies a relatively high incidence of RSPO3 rearrangements in aCRC and a strong association with clinical features.Furthermore,we find that RSPO3 fusions are associated with poorer OS.
