Background：Src homology 2 domain-containing protein tyrosine phosphatase-2 （SHP-2） is a kind of intracellular protein tyrosine phosphatase.Studies have revealed its roles in various disease,however,whether SHP-2 in...Background：Src homology 2 domain-containing protein tyrosine phosphatase-2 （SHP-2） is a kind of intracellular protein tyrosine phosphatase.Studies have revealed its roles in various disease,however,whether SHP-2 involves in renal fibrosis remains unclear.The aim of this study was to explore the roles of myeloid cells SHP-2 in renal interstitial fibrosis.Methods：Myeloid cells SHP-2 gene was conditionally knocked-out （CKO） in mice using loxP-Cre system,and renal interstitial fibrosis was induced by unilateral ureter obstruction （UUO）.The total collagen deposition in the renal interstitium was assessed using picrosirius red stain.F4/80 immunostaing was used to evaluate macrophage infiltration in renal tubular interstitium.Quantitative real-time polymerase chain reaction and enzyme linked immunosorbent assay were used to analyze the production of cytokines in the kidney.Transferase-mediated dUTP nick-end labeling stain was used to assess the apoptotic renal tubular epithelial cells.Results：Src homology 2 domain-containing protein tyrosine phosphatase-2 gene CKO in myeloid cells significantly reduced collagen deposition in the renal interstitium after UUO.Macrophage infiltration was evidently decreased in renal tubular interstitium of SHP-2 CKO mice.Meanwhile,the production of pro-inflammatory cytokines was significantly suppressed in SHP-2 CKO mice.However,no significant difference was observed in the number of apoptotic renal tubular epithelial cells between wild-type and SHP-2 CKO mice.Conclusions：Our observations suggested that SHP-2 in myeloid cells plays a pivotal role in the pathogenesis of renal fibrosis,and that silencing of SHP-2 gene in myeloid cells may protect renal from inflammatory damage and prevent renal fibrosis after renal injury.展开更多
包含Src同源2结构域的蛋白酪氨酸磷酸酶2(Src homology region 2-containing protein tyrosine phosphatase 2,SHP2)是目前唯一被证实具有促癌作用的细胞质蛋白酪氨酸磷酸酶,在多种恶性肿瘤中高表达。SHP2可以通过介导受体酪氨酸激酶(Re...包含Src同源2结构域的蛋白酪氨酸磷酸酶2(Src homology region 2-containing protein tyrosine phosphatase 2,SHP2)是目前唯一被证实具有促癌作用的细胞质蛋白酪氨酸磷酸酶,在多种恶性肿瘤中高表达。SHP2可以通过介导受体酪氨酸激酶(Receptor tyrosine kinase, RTK)下游的RAS/ERK、PI3K/Akt和JAK/STAT等信号通路促进肿瘤发生发展,影响肿瘤预后。同时,SHP2参与调控PD-1/PD-L1、CTLA-4、BLTA和TIGIT等免疫检查点信号通路,对于肿瘤微环境中各种免疫细胞都有重要的调节作用。靶向SHP2不仅可以通过抑制RTK下游信号通路,还可以通过改善免疫微环境治疗恶性肿瘤。因此,SHP2具有免疫与靶向双重治疗肿瘤的功能,作为抗肿瘤治疗的靶点展现出极高的潜能与价值。展开更多
Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibi...Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.展开更多
Background China is one of the countries with the highest incidence of H. pylori and more than 9090 isolates possessed the cagA gene. This study was to evaluate the biological activity of the H.pylori virulence facto...Background China is one of the countries with the highest incidence of H. pylori and more than 9090 isolates possessed the cagA gene. This study was to evaluate the biological activity of the H.pylori virulence factor cagA isolated from Chinese patients. Methods cagA DNA fragments were amplified from the genomic DNA and subsequently cloned into the mammalian expression vector for cell transfection and DNA sequencing. cagA protein, phosphorylated-tyrosine cagA and the complex of cagA precipitated with SHP-2 were identified respectively by western blot in the crude cell lysate from conditionally immortalized gastric epithelial cells at 48 hours after transfection with cagA DNA. In addition, the ability of induction of scattering phenotype was examined after transient expression of cagA in AGS cells. Results The C-terminal half of cagA contained only one repeated sequence and three tandem five-amino-acid motifs glutamic acid-proline-isoleucine-tyrosine-alanine (EPIYA). Moreover, the amino acid sequence of D2 region in repeated sequence was aspartic acid-phenylanaline-aspartic acid (D-F-D) which was significantly distinguished from the three repeated sequences and aspartic acid-aspartic adid-leucine (D-D-L) in the western standard strain NCTC11637. Western blot revealed that cagA became phosphorylated in tyrosine site and bound with SHP-2 after transient expression of cagA DNA in gastric epithelial cells. Transient expression of cagA in AGS cells showed that cagA was able to induce the elongation phenotype although to a lesser extent than western strains.Conclusions cagA perturbs cell signaling pathways by binding with SHP-2. However, significant difference exists in amino acid sequence and biological function of cagA in Chinese compared with those of western countries.展开更多
基金grants from National Natural Science Foundation of China，National Natural Science Foundation of China for Youths，Shanghai Committee of Science and Technology General Program for Medicine，Key Project of Science and Innovation Foundation of Shanghai Ministry of Education，Military Fund for Health Care （No.13BJZ29）.Conflict of Interest：None declared
文摘Background：Src homology 2 domain-containing protein tyrosine phosphatase-2 （SHP-2） is a kind of intracellular protein tyrosine phosphatase.Studies have revealed its roles in various disease,however,whether SHP-2 involves in renal fibrosis remains unclear.The aim of this study was to explore the roles of myeloid cells SHP-2 in renal interstitial fibrosis.Methods：Myeloid cells SHP-2 gene was conditionally knocked-out （CKO） in mice using loxP-Cre system,and renal interstitial fibrosis was induced by unilateral ureter obstruction （UUO）.The total collagen deposition in the renal interstitium was assessed using picrosirius red stain.F4/80 immunostaing was used to evaluate macrophage infiltration in renal tubular interstitium.Quantitative real-time polymerase chain reaction and enzyme linked immunosorbent assay were used to analyze the production of cytokines in the kidney.Transferase-mediated dUTP nick-end labeling stain was used to assess the apoptotic renal tubular epithelial cells.Results：Src homology 2 domain-containing protein tyrosine phosphatase-2 gene CKO in myeloid cells significantly reduced collagen deposition in the renal interstitium after UUO.Macrophage infiltration was evidently decreased in renal tubular interstitium of SHP-2 CKO mice.Meanwhile,the production of pro-inflammatory cytokines was significantly suppressed in SHP-2 CKO mice.However,no significant difference was observed in the number of apoptotic renal tubular epithelial cells between wild-type and SHP-2 CKO mice.Conclusions：Our observations suggested that SHP-2 in myeloid cells plays a pivotal role in the pathogenesis of renal fibrosis,and that silencing of SHP-2 gene in myeloid cells may protect renal from inflammatory damage and prevent renal fibrosis after renal injury.
基金a Ph D fellowship by FCT-Fundacao para a Ciência Tecnologia (SFRH/BD/135868/2018)(to SSC)。
文摘Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.
文摘Background China is one of the countries with the highest incidence of H. pylori and more than 9090 isolates possessed the cagA gene. This study was to evaluate the biological activity of the H.pylori virulence factor cagA isolated from Chinese patients. Methods cagA DNA fragments were amplified from the genomic DNA and subsequently cloned into the mammalian expression vector for cell transfection and DNA sequencing. cagA protein, phosphorylated-tyrosine cagA and the complex of cagA precipitated with SHP-2 were identified respectively by western blot in the crude cell lysate from conditionally immortalized gastric epithelial cells at 48 hours after transfection with cagA DNA. In addition, the ability of induction of scattering phenotype was examined after transient expression of cagA in AGS cells. Results The C-terminal half of cagA contained only one repeated sequence and three tandem five-amino-acid motifs glutamic acid-proline-isoleucine-tyrosine-alanine (EPIYA). Moreover, the amino acid sequence of D2 region in repeated sequence was aspartic acid-phenylanaline-aspartic acid (D-F-D) which was significantly distinguished from the three repeated sequences and aspartic acid-aspartic adid-leucine (D-D-L) in the western standard strain NCTC11637. Western blot revealed that cagA became phosphorylated in tyrosine site and bound with SHP-2 after transient expression of cagA DNA in gastric epithelial cells. Transient expression of cagA in AGS cells showed that cagA was able to induce the elongation phenotype although to a lesser extent than western strains.Conclusions cagA perturbs cell signaling pathways by binding with SHP-2. However, significant difference exists in amino acid sequence and biological function of cagA in Chinese compared with those of western countries.
