During development, gene expression is spatiotemporally regulated by long-distance chromatin interactions between distal enhancers and target promoters. However, how specificity of the interactions between enhancers a...During development, gene expression is spatiotemporally regulated by long-distance chromatin interactions between distal enhancers and target promoters. However, how specificity of the interactions between enhancers and promoters is achieved remains largely unknown. As there are far more enhancers than promoters in mammalian genomes, the complexities of enhancer choice during gene regulation remain obscure. CTCF, the CCCTC-binding factor that directionally binds to a vast range of genomic sites known as CBSs(CTCF-binding sites), mediates oriented chromatin looping between a substantial set of distal enhancers and target promoters. To investigate mechanisms by which CTCF engages in enhancer choice, we used CRISPR/Cas9-based DNA-fragment editing to duplicate CBS-containing enhancers and promoters in the native genomic locus of the clustered Pcdhα genes. We found that the promoter is regulated by the proximal one among duplicated enhancers and that this choice is dependent on CTCF-mediated directional enhancer-promoter looping. In addition, gene expression is unaltered upon the switch of enhancers. Moreover, after promoter duplication, only the proximal promoter is chosen by CTCF-mediated directional chromatin looping to contact with the distal enhancer. Finally, we demonstrated that both enhancer activation and chromatin looping with the promoter are essential for gene expression. These findings have important implications regarding the role of CTCF in specific interactions between enhancers and promoters as well as developmental regulation of gene expression by enhancer switching.展开更多
In adult mammals, axon regeneration after central nervous system injury is very poor, resulting in persistent functional loss. Enhancing the ability of axonal outgrowth may be a potential treatment strategy because ma...In adult mammals, axon regeneration after central nervous system injury is very poor, resulting in persistent functional loss. Enhancing the ability of axonal outgrowth may be a potential treatment strategy because mature neurons of the adult central nervous system may retain the intrinsic ability to regrow axons after injury. The protocadherin （Pcdh） clusters are thought to function in neuronal morphogenesis and in the assembly of neural circuitry in the brain. We cultured primary hippocampal neurons from E17.5 Pcdhα deletion （del-α） mouse embryos. After culture for 1 day, axon length was obviously shorter in del-α neurons compared with wild-type neurons. RNA sequencing of hippocampal E17.5 RNA showed that expression levels of BDNF, Fmod, Nrp2, OGN, and Sema3d, which are associated with axon extension, were significantly down-regulated in the absence of the Pcdhα gene cluster. Using transmission electron microscopy, the ratio of myelinated nerve fibers in the axons of del-α hippocampal neurons was significantly decreased; myelin sheaths of P21 Pcdhα-del mice showed lamellar disorder, discrete appearance, and vacuoles. These results indicate that the Pcdhα cluster can promote the growth and myelination of axons in the neurodevelopmental stage.展开更多
When the physiopathology of membranous nephropathy was first described,almost 30%of cases were recognized to be secondary to well-known diseases such as autoimmune diseases,tumors or infections.The remaining 70%cases ...When the physiopathology of membranous nephropathy was first described,almost 30%of cases were recognized to be secondary to well-known diseases such as autoimmune diseases,tumors or infections.The remaining 70%cases were called primary membranous nephropathy as the exact mechanism or pathogenic factor involved was unknown.The discovery of the M type phospholipase A2 receptor and thrombospondin type 1 domain containing 7A as causative antigens in these“so called”primary membranous nephropathies provided new insights into the effective causes of a large proportion of these cases.Novel techniques such as laser microdissection and tandem mass spectrometry as well as immunochemistry with antibodies directed against novel proteins allowed the confirmation of new involved antigens.Finally,using confocal microscopy to localize these new antigens and immunoglobulin G and Western blot analysis of serum samples,these new antigens were detected on the glomerular membrane,and the related antibodies were detected in serum samples.The same antigens have been recognized in some cases of secondary membranous disease due to autoimmune diseases,tumors and infections.This has allowed examination of the relationship between antigens in primary membranous nephropathy and their presence in some secondary nephropathies.The aim of this study is to describe the characteristics of the new antigens discovered and their association with other diseases.展开更多
Defects in the endothelial cell barrier accompany diverse malfunctions of the central nervous system such as neurodegenerative diseases,stroke,traumatic brain injury,and systemic diseases such as sepsis,viral and bact...Defects in the endothelial cell barrier accompany diverse malfunctions of the central nervous system such as neurodegenerative diseases,stroke,traumatic brain injury,and systemic diseases such as sepsis,viral and bacterial infections,and cancer.Compromised endothelial sealing leads to leaking blood vessels,followed by vasogenic edema.Brain edema as the most common complication caused by stroke and traumatic brain injury is the leading cause of death.Brain microvascular endothelial cells,together with astrocytes,pericytes,microglia,and neurons form a selective barrier,the so-called blood-brain barrier,which regulates the movement of molecules inside and outside of the brain.Mechanisms that regulate blood-brain barrier permeability in health and disease are complex and not fully understood.Several newly discovered molecules that are involved in the regulation of cellular processes in brain microvascular endothelial cells have been described in the literature in recent years.One of these molecules that are highly expressed in brain microvascular endothelial cells is protocadherin gamma C3.In this review,we discuss recent evidence that protocadherin gamma C3 is a newly identified key player involved in the regulation of vascular barrier function.展开更多
Objective: To investigate the methylation status of the PCDH8 (Protocadherin-8) gene in gastric cancer tissues and find out the relationship between methylation status of the PCDH8 and clinicopathological features in ...Objective: To investigate the methylation status of the PCDH8 (Protocadherin-8) gene in gastric cancer tissues and find out the relationship between methylation status of the PCDH8 and clinicopathological features in gastric cancer patients. Methods: We first investigated the methylation status of the PCDH8 (Protocadherin-8) gene in 65 gastric cancer and detected aberrant promoter methylation in gastric cancers; and then analyzed he relationship between methylation status of the PCDH8 and clinicopathological status with SPSS 13.0 software. Results: We first investigated the methylation status of the PCDH8 (Protocadherin-8) gene in 65 gastric cancer and detected aberrant promoter methylation in 36 of 65 (55.4%) gastric cancers. There was no significant difference in the distribution of patients with methylation or unmethylation of PCDH8 in terms of age, sex, tumor size, distant metastasis, or TNM stage. Methylation of PCDH8 was significantly correlated to negative pathological lymph node metastasis (P=0.038) and tumor differentiation (P=0.01). These two factors were proved to be of prognostic importance. Conclusion: Methylated PCDH8 seems to have a trend for worse prognosis in gastric cancer. However, a further large series of tumor samples and a longer follow-up period are required to elucidate its potential role.展开更多
Clustered protocadherins(Pcdhs)are a large family of cadherin-like cell adhesion proteins that are central for neurite selfavoidance and neuronal connectivity in the brain.Their downstream nonreceptor tyrosine kinase ...Clustered protocadherins(Pcdhs)are a large family of cadherin-like cell adhesion proteins that are central for neurite selfavoidance and neuronal connectivity in the brain.Their downstream nonreceptor tyrosine kinase Pyk2(proline-rich tyrosine kinase 2,also known as Ptk2b,Cakb,Raftk,Fak2,and Cadtk)is predominantly expressed in the hippocampus.We constructed Pyk2-null mouse lines and found that these mutant mice showed enhancement in contextual fear memory,without significant change in auditory-cued and spatial-referenced learning and memory.In addition,by preparing Y402F mutant mice,we observed that Pyk2 suppressed contextual fear memory in an autophosphorylation-independent manner.Moreover,using high-throughput RNA sequencing,we found that immediate early genes,such as Npas4,cFos,Zif268/Egr1,Arc,and Nr4a1,were enhanced in Pyk2-null mice.We further showed that Pyk2 disruption affected pyramidal neuronal complexity and spine dynamics.Thus,we demonstrated that Pyk2 is a novel fear memory suppressor molecule and Pyk2-null mice provide a model for understanding fearrelated disorders.These findings have interesting implications regarding dysregulation of the Pcdh–Pyk2 axis in neuropsychiatric disorders.展开更多
Objective:To study the effect of protocadherin 10 (PCDH10) on infiltrative growth and epithelial-mesenchymal transition of cancer cells in gastric cancer.Methods: The patients with gastric cancer who underwent surgica...Objective:To study the effect of protocadherin 10 (PCDH10) on infiltrative growth and epithelial-mesenchymal transition of cancer cells in gastric cancer.Methods: The patients with gastric cancer who underwent surgical resection in Panzhihua Central Hospital were selected as the research subjects, and the gastric cancer lesions and adjacent lesions were collected after surgical resection to determine the mRNA expression of PCDH10 gene and epithelial-mesenchymal transition genes as well as the protein levels of proteases and their inhibitory molecules.Results: PCDH10, TIMP1, TIMP2, RASAL2 and E-cadherin mRNA expression levels in gastric cancer lesions were significantly lower than those in adjacent lesions whereas Vav2, Vav3, CatB, MMP9, ZEB1, Twist1 and Vimentin contents were significantly higher than those in adjacent lesions;Vav2, Vav3, CatB, MMP9, ZEB1, Twist1 and Vimentin contents in gastric caner lesions with lower PCDH10 expression were significantly higher than those in gastric caner lesions with higher PCDH10 expression whereas TIMP1, TIMP2, RASAL2 and E-cadherin contents were significantly lower than those in gastric caner lesions with higher PCDH10 expression.Conclusion: The low expression of PCDH10 in gastric cancer can promote the infiltrative growth and epithelial-mesenchymal transition of cancer cells.展开更多
背景与目的:编码原钙黏蛋白10(protocadherin-10,PCDH10)的PCDH10基因启动子甲基化与胃癌患者不良预后相关。但PCDH10表达水平与胃癌预后的关系不明确。该研究旨在分析PCDH10表达水平与胃癌预后及临床病理因素间的关系,寻找预测胃癌患...背景与目的:编码原钙黏蛋白10(protocadherin-10,PCDH10)的PCDH10基因启动子甲基化与胃癌患者不良预后相关。但PCDH10表达水平与胃癌预后的关系不明确。该研究旨在分析PCDH10表达水平与胃癌预后及临床病理因素间的关系,寻找预测胃癌患者复发及死亡风险的指标。方法:采用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)方法检测115对胃癌组织与相应癌旁组织PCDH10 m RNA的表达水平,分析PCDH10 m RNA的表达水平与预后及临床病理因素的关系。采用Logistic回归分析建立预测患者5年内复发或死亡风险的模型。结果:PCDH10 m RNA低表达组与非低表达组相比,无进展生存时间(progression-free survival,PFS)与总生存时间(overall survival,OS)显著延长(P值分别为0.046与0.033),淋巴结转移较少(P=0.001),TNM分期较早(P=0.001)。Cox单因素分析发现,Lauren分型、T分期、N分期、M分期及PCDH10 m RNA表达水平与PFS及OS显著相关。包含PCDH10作为参数的Logistic回归模型对胃癌患者术后5年内复发或死亡风险的预测效率与仅包含传统临床病理学参数的Logistic回归模型的预测效率相当。结论:PCDH10低表达胃癌患者淋巴结转移较少,TNM分期较早,预后较好,可以作为预测胃癌患者预后的辅助指标。基于PCDH10表达水平的Logistic回归模型可以在淋巴结转移情况不明时起到辅助判断患者预后的作用。展开更多
基金grants from Ministry of Science and Technology of China (2017YFA0504203 and 2018YFC1004504)the National Natural Science Foundation of China (31630039)。
文摘During development, gene expression is spatiotemporally regulated by long-distance chromatin interactions between distal enhancers and target promoters. However, how specificity of the interactions between enhancers and promoters is achieved remains largely unknown. As there are far more enhancers than promoters in mammalian genomes, the complexities of enhancer choice during gene regulation remain obscure. CTCF, the CCCTC-binding factor that directionally binds to a vast range of genomic sites known as CBSs(CTCF-binding sites), mediates oriented chromatin looping between a substantial set of distal enhancers and target promoters. To investigate mechanisms by which CTCF engages in enhancer choice, we used CRISPR/Cas9-based DNA-fragment editing to duplicate CBS-containing enhancers and promoters in the native genomic locus of the clustered Pcdhα genes. We found that the promoter is regulated by the proximal one among duplicated enhancers and that this choice is dependent on CTCF-mediated directional enhancer-promoter looping. In addition, gene expression is unaltered upon the switch of enhancers. Moreover, after promoter duplication, only the proximal promoter is chosen by CTCF-mediated directional chromatin looping to contact with the distal enhancer. Finally, we demonstrated that both enhancer activation and chromatin looping with the promoter are essential for gene expression. These findings have important implications regarding the role of CTCF in specific interactions between enhancers and promoters as well as developmental regulation of gene expression by enhancer switching.
基金supported by a grant from the Science and Technology Commission of Shanghai Municipality of China,No.12441900702
文摘In adult mammals, axon regeneration after central nervous system injury is very poor, resulting in persistent functional loss. Enhancing the ability of axonal outgrowth may be a potential treatment strategy because mature neurons of the adult central nervous system may retain the intrinsic ability to regrow axons after injury. The protocadherin （Pcdh） clusters are thought to function in neuronal morphogenesis and in the assembly of neural circuitry in the brain. We cultured primary hippocampal neurons from E17.5 Pcdhα deletion （del-α） mouse embryos. After culture for 1 day, axon length was obviously shorter in del-α neurons compared with wild-type neurons. RNA sequencing of hippocampal E17.5 RNA showed that expression levels of BDNF, Fmod, Nrp2, OGN, and Sema3d, which are associated with axon extension, were significantly down-regulated in the absence of the Pcdhα gene cluster. Using transmission electron microscopy, the ratio of myelinated nerve fibers in the axons of del-α hippocampal neurons was significantly decreased; myelin sheaths of P21 Pcdhα-del mice showed lamellar disorder, discrete appearance, and vacuoles. These results indicate that the Pcdhα cluster can promote the growth and myelination of axons in the neurodevelopmental stage.
文摘When the physiopathology of membranous nephropathy was first described,almost 30%of cases were recognized to be secondary to well-known diseases such as autoimmune diseases,tumors or infections.The remaining 70%cases were called primary membranous nephropathy as the exact mechanism or pathogenic factor involved was unknown.The discovery of the M type phospholipase A2 receptor and thrombospondin type 1 domain containing 7A as causative antigens in these“so called”primary membranous nephropathies provided new insights into the effective causes of a large proportion of these cases.Novel techniques such as laser microdissection and tandem mass spectrometry as well as immunochemistry with antibodies directed against novel proteins allowed the confirmation of new involved antigens.Finally,using confocal microscopy to localize these new antigens and immunoglobulin G and Western blot analysis of serum samples,these new antigens were detected on the glomerular membrane,and the related antibodies were detected in serum samples.The same antigens have been recognized in some cases of secondary membranous disease due to autoimmune diseases,tumors and infections.This has allowed examination of the relationship between antigens in primary membranous nephropathy and their presence in some secondary nephropathies.The aim of this study is to describe the characteristics of the new antigens discovered and their association with other diseases.
文摘Defects in the endothelial cell barrier accompany diverse malfunctions of the central nervous system such as neurodegenerative diseases,stroke,traumatic brain injury,and systemic diseases such as sepsis,viral and bacterial infections,and cancer.Compromised endothelial sealing leads to leaking blood vessels,followed by vasogenic edema.Brain edema as the most common complication caused by stroke and traumatic brain injury is the leading cause of death.Brain microvascular endothelial cells,together with astrocytes,pericytes,microglia,and neurons form a selective barrier,the so-called blood-brain barrier,which regulates the movement of molecules inside and outside of the brain.Mechanisms that regulate blood-brain barrier permeability in health and disease are complex and not fully understood.Several newly discovered molecules that are involved in the regulation of cellular processes in brain microvascular endothelial cells have been described in the literature in recent years.One of these molecules that are highly expressed in brain microvascular endothelial cells is protocadherin gamma C3.In this review,we discuss recent evidence that protocadherin gamma C3 is a newly identified key player involved in the regulation of vascular barrier function.
文摘Objective: To investigate the methylation status of the PCDH8 (Protocadherin-8) gene in gastric cancer tissues and find out the relationship between methylation status of the PCDH8 and clinicopathological features in gastric cancer patients. Methods: We first investigated the methylation status of the PCDH8 (Protocadherin-8) gene in 65 gastric cancer and detected aberrant promoter methylation in gastric cancers; and then analyzed he relationship between methylation status of the PCDH8 and clinicopathological status with SPSS 13.0 software. Results: We first investigated the methylation status of the PCDH8 (Protocadherin-8) gene in 65 gastric cancer and detected aberrant promoter methylation in 36 of 65 (55.4%) gastric cancers. There was no significant difference in the distribution of patients with methylation or unmethylation of PCDH8 in terms of age, sex, tumor size, distant metastasis, or TNM stage. Methylation of PCDH8 was significantly correlated to negative pathological lymph node metastasis (P=0.038) and tumor differentiation (P=0.01). These two factors were proved to be of prognostic importance. Conclusion: Methylated PCDH8 seems to have a trend for worse prognosis in gastric cancer. However, a further large series of tumor samples and a longer follow-up period are required to elucidate its potential role.
基金supported by grants from the National Natural Science Foundation of China(31200825 to L.S.and 31630039 to Q.W.)the Ministry of Science and Technology of China(2017YFA0504203 and 2018YFC1004504)+2 种基金the Science and Technology Commission of Shanghai Municipality(19JC1412500 and 21DZ2210200 to Q.W.)Shanghai Jiao Tong University Scientific and Technological Innovation Funds(17JCYB12 to L.S.)Q.W.is a Shanghai Subject Chief Scientist.
文摘Clustered protocadherins(Pcdhs)are a large family of cadherin-like cell adhesion proteins that are central for neurite selfavoidance and neuronal connectivity in the brain.Their downstream nonreceptor tyrosine kinase Pyk2(proline-rich tyrosine kinase 2,also known as Ptk2b,Cakb,Raftk,Fak2,and Cadtk)is predominantly expressed in the hippocampus.We constructed Pyk2-null mouse lines and found that these mutant mice showed enhancement in contextual fear memory,without significant change in auditory-cued and spatial-referenced learning and memory.In addition,by preparing Y402F mutant mice,we observed that Pyk2 suppressed contextual fear memory in an autophosphorylation-independent manner.Moreover,using high-throughput RNA sequencing,we found that immediate early genes,such as Npas4,cFos,Zif268/Egr1,Arc,and Nr4a1,were enhanced in Pyk2-null mice.We further showed that Pyk2 disruption affected pyramidal neuronal complexity and spine dynamics.Thus,we demonstrated that Pyk2 is a novel fear memory suppressor molecule and Pyk2-null mice provide a model for understanding fearrelated disorders.These findings have interesting implications regarding dysregulation of the Pcdh–Pyk2 axis in neuropsychiatric disorders.
文摘Objective:To study the effect of protocadherin 10 (PCDH10) on infiltrative growth and epithelial-mesenchymal transition of cancer cells in gastric cancer.Methods: The patients with gastric cancer who underwent surgical resection in Panzhihua Central Hospital were selected as the research subjects, and the gastric cancer lesions and adjacent lesions were collected after surgical resection to determine the mRNA expression of PCDH10 gene and epithelial-mesenchymal transition genes as well as the protein levels of proteases and their inhibitory molecules.Results: PCDH10, TIMP1, TIMP2, RASAL2 and E-cadherin mRNA expression levels in gastric cancer lesions were significantly lower than those in adjacent lesions whereas Vav2, Vav3, CatB, MMP9, ZEB1, Twist1 and Vimentin contents were significantly higher than those in adjacent lesions;Vav2, Vav3, CatB, MMP9, ZEB1, Twist1 and Vimentin contents in gastric caner lesions with lower PCDH10 expression were significantly higher than those in gastric caner lesions with higher PCDH10 expression whereas TIMP1, TIMP2, RASAL2 and E-cadherin contents were significantly lower than those in gastric caner lesions with higher PCDH10 expression.Conclusion: The low expression of PCDH10 in gastric cancer can promote the infiltrative growth and epithelial-mesenchymal transition of cancer cells.
文摘背景与目的:编码原钙黏蛋白10(protocadherin-10,PCDH10)的PCDH10基因启动子甲基化与胃癌患者不良预后相关。但PCDH10表达水平与胃癌预后的关系不明确。该研究旨在分析PCDH10表达水平与胃癌预后及临床病理因素间的关系,寻找预测胃癌患者复发及死亡风险的指标。方法:采用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)方法检测115对胃癌组织与相应癌旁组织PCDH10 m RNA的表达水平,分析PCDH10 m RNA的表达水平与预后及临床病理因素的关系。采用Logistic回归分析建立预测患者5年内复发或死亡风险的模型。结果:PCDH10 m RNA低表达组与非低表达组相比,无进展生存时间(progression-free survival,PFS)与总生存时间(overall survival,OS)显著延长(P值分别为0.046与0.033),淋巴结转移较少(P=0.001),TNM分期较早(P=0.001)。Cox单因素分析发现,Lauren分型、T分期、N分期、M分期及PCDH10 m RNA表达水平与PFS及OS显著相关。包含PCDH10作为参数的Logistic回归模型对胃癌患者术后5年内复发或死亡风险的预测效率与仅包含传统临床病理学参数的Logistic回归模型的预测效率相当。结论:PCDH10低表达胃癌患者淋巴结转移较少,TNM分期较早,预后较好,可以作为预测胃癌患者预后的辅助指标。基于PCDH10表达水平的Logistic回归模型可以在淋巴结转移情况不明时起到辅助判断患者预后的作用。
