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目的 探讨蛋白酪氨酸磷酸酶非受体型22(the protein tyrosine phosphatage nonreceptor 22,PTPN22)基因1123G>C(rs2488457)单核苷酸多态性(SNP)与类风湿关节炎(RA)的关系.方法 采用实时荧光定量PCR对200例RA患者,100例其他风湿病患者,200名健康体检者PTPN22基因进行分型.用SPSS 11.0软件进行统计学分析和行×列表X2检验.结果 RA组PTPN22 CC基因型频率(0.120)与其他风湿病组(0.020)及健康对照组(0.015)比较差异有统计学意义(X2 值分别为18.708和24.337,P均<0.01),而其他风湿病组与健康对照组比较,差异无统计学意义(X2值为1.066,P>0.05);RA组C等位基因频率(0.360)明显高于其他风湿病组(0.190)及健康对照组(0.215),且差异有统计学意义(P<.005).结论 PTPN22基因可能是RA的易感基因和RA等自身免疫病治疗的靶基因之一.  相似文献   

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目的探讨乳腺浸润性导管癌及乳腺不典型增生组织中蛋白酪氨酸磷酸酶PRL-3表达情况。方法采用SP法及RT-PCR方法检测60份乳腺癌组织及50份乳腺不典型增生组织标本中PRL-3表达情况,分析PRL-3与乳腺浸润性导管癌临床病理特征的关系。结果在乳腺癌癌变过程中PRL-3表达阳性率呈递增趋势;PRL-3表达与有无淋巴结转移有相关性(P=0.011);PRL-3在乳腺癌中表达明显高于乳腺不典型增生组织(P〈0.05)。结论乳腺癌组织中PRL-3在蛋白及基因水平呈高表达,一定程度上提示PRL-3与乳腺癌发生密切相关。  相似文献   

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Congenital anomalies affecting the ureter-bladder junction are frequent in newborns and are often associated with other developmental defects. However, the molecular and morphological processes underlying these malformations are still poorly defined. In this study, we identified the leukocyte antigen–related (LAR) family protein tyrosine phosphatase, receptor type, S and F (Ptprs and Ptprf [also known as Lar], respectively), as crucially important for distal ureter maturation and craniofacial morphogenesis in the mouse. Embryos lacking both Ptprs and Ptprf displayed severe urogenital malformations, characterized by hydroureter and ureterocele, and craniofacial defects such as cleft palate, micrognathia, and exencephaly. The detailed analysis of distal ureter maturation, the process by which the ureter is displaced toward its final position in the bladder wall, leads us to propose a revised model of ureter maturation in normal embryos. This process was deficient in embryos lacking Ptprs and Ptprf as a result of a marked reduction in intrinsic programmed cell death, thereby causing urogenital system malformations. In cell culture, Ptprs bound and negatively regulated the phosphorylation and signaling of the Ret receptor tyrosine kinase, whereas Ptprs-induced apoptosis was inhibited by Ret expression. Together, these results suggest that ureter positioning is controlled by the opposing actions of Ret and LAR family phosphatases regulating apoptosis-mediated tissue morphogenesis.  相似文献   

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目的:从红细胞膜蛋白磷酸化改变的角度探讨葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症溶血的机制。方法:Western blot法检测G6PD缺乏症的红细胞膜蛋白磷酸化的改变以及二硫苏糖醇(DTT)对蛋白磷酸化的影响;以对硝基苯磷酸(PNPP)为底物,测磷酸酪氨酸磷酸酶(PTPs)活性以探讨磷酸化改变的可能成因。结果:G6PD缺乏的红细胞膜带3(Band 3)蛋白酪氨酸的磷酸化水平较正常对照明显增多,而PTPs活性检测较正常对照组明显减弱;DTT处理的G6PD缺乏红细胞,其膜Band 3蛋白酪氨酸的磷酸化与未处理者无明显差异,PTPs活性检测结果与未处理者亦无显著差异。结论:氧化致使G6PD缺乏红细胞的PTPs活性减弱,膜Band 3蛋白酪氨酸磷酸化增强,成为红细胞溶血的一个重要原因。但PTPs巯基的改变并不是影响PTPs活性的唯一因素。  相似文献   

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Receptor protein tyrosine kinases (RTKs) transmit downstream signals via interactions with secondary signaling molecules containing SH2 domains. Although many SH2-phosphotyrosyl interactions have been defined in vitro, little is known about the physiological significance of specific RTK/SH2 interactions in vivo. Also, little is known about the mechanisms by which specific RTKs interact with and/or are regulated by specific protein tyrosine phosphatases (PTPs). To address such issue, we carried out a genetic analysis of the previously reported biochemical interaction between the RTK c-Kit, encoded at the W locus, and the SH2-containing non-transmembrane PTP SHP1, encoded at the motheaten (me) locus (1). Mice carrying a kinase-defective allele of c-Kit (Wv/+) were crossed with me/+ mice, which carry one effectively null allele of SHP1, and then backcrossed to generate all possible allelic combinations. Our results indicate strong intergenic complementation between these loci in hematopoietic progenitor cells. Compared to progenitors purified from normal mice, bone marrow progenitor cells (lin-) from me/me mice markedly hyper-proliferated in response to Kit ligand (KL). stimulation. Superimposition of the me/me genotype increased the number of one marrow-derived CFU-E from Wv/+ mice. Conversely, the presence of one or two copies of Wv decreased the number of macrophages and granulocytes in me/me lung, skin, peripheral blood and bone marrow, thereby decreasing the severity of the me/me phenotype. The decrease in dermal mast cells in Wv/Wv mice was rescued to levels found in Wv/+mice by superimposition of the me/me genotype. Surprisingly, however, the presence or absence of SHP1 had no effect on the proliferative response of bone marrow-derived cultured mast cells to KL or IL3 ex vivo. Nevertheless, the immediate-early response to KL stimulation, as measured by KL-induced tyrosyl phosphorylation, was substantially increased in mast cells from Wv/+:me/me compared to Wv/ +:+/+ mice, strongly suggesting that SHP1 directly dephosphorylates and regulates c-Kit. Taken together, our results establish that SHP1 negatively regulates signaling from c-Kit in vivo, but in a cell type- specific manner.  相似文献   

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小胶质细胞NLRP3炎症小体激活正在成为神经退行性变期间神经炎症的关键因素。β-淀粉样蛋白和α-突触核蛋白等致病蛋白的聚集体可触发小胶质细胞NLRP3激活,并导致半胱氨酸天冬氨酸酶激活和白介素-1β分泌。半胱氨酸天冬氨酸酶和白介素-1β均促进肌萎缩侧索硬化(ALS)小鼠SOD1G93A模型的疾病进展,这提示小胶质细胞NLRP3在该进程中起作用。然而,先前的研究表明SOD1G93A模型小鼠的小胶质细胞并不表达NLRP3,并且SOD1G93A蛋白在小胶质细胞中产生白介素-1β不依赖于NLRP3。本研究展示了使用Nlrp3-GFP基因敲入小鼠,在SOD1G93A小鼠中小胶质细胞表达NLRP3。结果表明,聚集和可溶性SOD1G93A均以剂量和时间依赖性方式激活小鼠原代小胶质细胞中的炎性体,导致半胱氨酸天冬氨酸酶和白介素-1β裂解、ASC斑点形成和白介素-1β分泌。重要的是,SOD1G93A不能诱导缺乏Nlrp3的小胶质细胞或用特异性NLRP3抑制剂MCC950预处理的小胶质细胞分泌白介素-1β,这证实NLRP3是介导SOD1诱导的小胶质细胞白介素-1β分泌的关键炎性体复合物。在TDP-43Q331K ALS小鼠模型中也观察到小胶质细胞NLRP3上调,并且TDP-43野生型和突变蛋白也能以NLRP3依赖性方式激活小胶质细胞炎症小体。从机制上,本研究确定活性氧簇和ATP的产生是SOD1G93A介导的NLRP3激活所需的关键事件。总之,本研究的数据表明ALS小胶质细胞表达NLRP3,病理性ALS蛋白激活了小胶质细胞NLRP3炎性体。因此,抑制NLRP3可能是阻止小胶质细胞神经炎症和ALS疾病进展的潜在治疗方法。  相似文献   

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目的分析人早幼粒细胞白血病细胞内STAT3的酪氨酸磷酸化活化情况。方法培养人早幼粒细胞白血病细胞株HL-60,分别用浓度为0,1.0,10,100 ng/ml的人白细胞介素(hIL)-5刺激,然后利用特异性抗体,用免疫沉淀法、聚丙烯酰胺凝胶(SDS PAGE)电泳及Western Blot方法进行检测。结果检测到HL-60细胞内不同浓度的STAT3表达。结论一定浓度的人IL-5能同时诱导HL-60细胞内STAT3α和STAT3α的酪氨酸(Y705)磷酸化,且在一定范围内这种诱导作用与IL-5的浓度呈正相关。  相似文献   

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BACKGROUND: Protein tyrosine phosphatase 1B (PTPN1) dephosphorylates insulin receptors and attenuates insulin signaling. Polymorphisms in the coding sequence of PTPN1 have been variably associated with type 2 diabetes (T2D). We hypothesized that variations within the PTPN1 promoter might contribute to the development of T2D and related metabolic traits. METHODS: We screened 2.0 kb of PTPN1 promoter in 174 T2D patients and 412 controls using PCR and denaturing HPLC. Association analysis was performed between diabetes and related traits and single-nucleotide polymorphism genotypes. We functionally tested 2 variants (-1023C>A and -51delA) by measuring their influence on luciferase activity in HepG2 cells and performing the electrophoretic mobility shift assay (EMSA). RESULTS: One common (-1023C>A) and 6 rare (-51delA, -451A>G, -467T>C, -1045G>A, -1286-3bp-del, and -1291-9bp-del) variants were identified in the PTPN1 promoter. The -1023(C) allele had significant association with T2D that disappeared after we adjusted for established diabetes risk factors. The alleles of -1023C>A and -51delA variants did not show significant effects on the biochemical markers after adjustment for established diabetes risk factors in the nondiabetic and diabetic groups separately. The -51delA variant decreased luciferase gene expression in HepG2 cells by 2-fold. EMSA revealed a weaker binding of -51delA to specific protein family proteins compared with the A allele. The -1023C>A variant had no influence in either experiment. CONCLUSIONS: The PTPN1 promoter variants -1023C>A and -51delA (which appears to be functional) were not associated with T2D or related traits in this study but must be investigated in a larger population to reveal any potential metabolic association.  相似文献   

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Genome-wide association studies revealed that loss-of-function mutations in protein tyrosine phosphatase non-receptor type 2 (PTPN2) increase the risk of developing chronic immune diseases, such as inflammatory bowel disease (IBD) and celiac disease. These conditions are associated with increased intestinal permeability as an early etiological event. The aim of this study was to examine the consequences of deficient activity of the PTPN2 gene product, T cell protein tyrosine phosphatase (TCPTP), on intestinal barrier function and tight junction organization in vivo and in vitro. Here, we demonstrate that TCPTP protected against intestinal barrier dysfunction induced by the inflammatory cytokine IFN-γ by 2 mechanisms: it maintained localization of zonula occludens 1 and occludin at apical tight junctions and restricted both expression and insertion of the cation pore-forming transmembrane protein, claudin-2, at tight junctions through upregulation of the inhibitory cysteine protease, matriptase. We also confirmed that the loss-of-function PTPN2 rs1893217 SNP was associated with increased intestinal claudin-2 expression in patients with IBD. Moreover, elevated claudin-2 levels and paracellular electrolyte flux in TCPTP-deficient intestinal epithelial cells were normalized by recombinant matriptase. Our findings uncover distinct and critical roles for epithelial TCPTP in preserving intestinal barrier integrity, thereby proposing a mechanism by which PTPN2 mutations contribute to IBD.  相似文献   

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Cross-linking B cell antigen receptor (BCR) elicits early signal transduction events, including activation of protein tyrosine kinases, phosphorylation of receptor components, activation of phospholipase C- gamma (PLC-gamma), and increases in intracellular free Ca2+. In this article, we report that cross-linking the BCR led to a rapid translocation of cytosolic protein tyrosine phosphatase (PTP) 1C to the particulate fraction, where it became associated with a 140-150-kD tyrosyl-phosphorylated protein. Western blotting analysis identified this 140-150-kD protein to be CD22. The association of PTP-1C with CD22 was mediated by the NH2-terminal Src homology 2 (SH2) domain of PTP-1C. Complexes of either CD22/PTP-1C/Syk/PLC-gamma(1) could be isolated from B cells stimulated by BCR engagement or a mixture of hydrogen peroxidase and sodium orthovanadate, respectively. The binding of PLC- gamma(1) and Syk to tyrosyl-phosphorylated CD22 was mediated by the NH2- terminal SH2 domain of PLC-gamma(1) and the COOH-terminal SH2 domain of Syk, respectively. These observations suggest that tyrosyl- phosphorylated CD22 may downmodulate the activity of this complex by dephosphorylation of CD22, Syk, and/or PLC-gamma(1). Transient expression of CD22 and a null mutant of PTP-1C (PTP-1CM) in COS cells resulted in an increase in tyrosyl phosphorylation of CD22 and its interaction with PTP-1CM. By contrast, CD22 was not tyrosyl phosphorylated or associated with PTP-1CM in the presence of wild-type PTP-1C. These results suggest that tyrosyl-phosphorylated CD22 may be a substrate for PTP-1C regulates tyrosyl phosphorylation of CD22.  相似文献   

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BACKGROUND: Endothelial nitric oxide synthase (eNOS) activity in endothelial cells is regulated by post-translational phosphorylation of critical serine, threonine and tyrosine residues in response to a variety of stimuli. However, the post-translational regulation of eNOS in platelets is poorly defined. OBJECTIVES: We investigated the role of tyrosine phosphorylation in the regulation of platelet eNOS activity. METHODS: Tyrosine phosphorylation of eNOS and interaction with the tyrosine phosphatase SHP-1 were investigated by coimmunoprecipitation and immunoblotting. An in vitro immunoassay was used to determine eNOS activity together with the contribution of protein tyrosine phosphorylation. RESULTS: We found platelet eNOS was tyrosine phosphorylated under basal conditions. Thrombin induced a dose- and time-dependent increase in eNOS activity without altering overall level of tyrosine phosphorylation, although we did observe evidence of minor tyrosine dephosphorylation. In vitro tyrosine dephosphorylation of platelet eNOS using a recombinant protein tyrosine phosphatase enhanced thrombin-induced activity compared to thrombin alone, but had no effect on endothelial eNOS activity either at basal or after stimulation with bradykinin. Having shown that dephosphorylation could modulate platelet eNOS activity we examined the role of potential protein phosphatases important for platelet eNOS activity. We found SHP-1 protein tyrosine phosphatase, co-associated with platelet eNOS in resting platelets, but does not associate with eNOS in endothelial cells. Stimulation of platelets with thrombin increased SHP-1 association with eNOS, while inhibition of SHP-1 abolished the ability of thrombin to induce elevated eNOS activity. CONCLUSIONS: Our data suggest a novel role for tyrosine dephosphorylation in platelet eNOS activation, which may be mediated by SHP-1.  相似文献   

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The Na(+)/Cl(-)-dependent, hemicholinium-3-sensitive choline transporter (CHT) provides choline for acetylcholine biosynthesis. Recent studies show that CHT contains canonical protein kinase C (PKC) serine and threonine residues. We examined the ability of PKC and serine/threonine protein phosphatase 1/2A (PP1/PP2A) to regulate CHT function, surface expression, and phosphorylation. In mouse crude striatal and hippocampal synaptosomes, PKC activators beta-phorbol 12-myristate 13-acetate (beta-PMA) and beta-phorbol 12,13-dibutyrate produced time- and concentration-dependent reductions in CHT function. PP1/PP2A inhibitors okadaic acid (OKA) and calyculin A (CL-A) produced a time- and concentration-dependent decrease in CHT function. However, tautomycin (PP1 inhibitor) and cyclosporin A (PP2B inhibitor) failed to alter CHT-mediated choline uptake. Choline transport kinetic studies following beta-PMA, OKA, and CL-A treatment revealed a reduction in the maximal choline transport velocity (V(max)) with no change in K(m) for choline. These modulators also produced no change in the total levels of CHT protein in the crude hippocampal and striatal synaptosomes; however, surface biotinylation studies using the membrane-impermeant N-hydroxysuccinimide-biotin in crude synaptosomes following treatment with beta-PMA, OKA, and CL-A indicate significant reductions of CHT levels in biotinylated fractions. Pretreatment with OKA alone, but not beta-PMA, significantly augmented the phosphorylation level of CHT proteins. Our findings suggest that neuronal PKC and PP1/PP2A activity may establish the level of function and surface expression of CHT. These studies also provide the first evidence that CHT is a phosphoprotein and that the basal PP1/PP2A activity may have a dominant role in controlling the levels of CHT phosphorylation.  相似文献   

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蛋白酪氨酸磷酸酶-1B(proteintyrosinephosphatase1B,PTP-1B)在人类各组织细胞中广泛表达,没有特异性受体,与细胞内不同蛋白底物作用可产生不同的生理反应,在体内主要受生长因子、蛋白激酶等的调节。目前研究发现在肥胖人群中存在胰岛素抵抗、瘦素抵抗、脂代谢异常等现象,这些现象与肥胖症的发病及发展关系密切;同时肥胖人群细胞内PTP-1B也表达明显增多,提示PTP-1B可能参与了肥胖症的发病。在动物实验中发现肥胖动物模型的PTP-1B表达增多;而其体重下降,PTP-1B表达也随之减少。PTP-1B基因缺失的小鼠在致肥胖饮食条件下也不出现肥胖,一系列动物实验进一步证实了PTP-1B与肥胖症之间的关系。这使人们普遍关注PTP-1B特异性抑制剂在肥胖治疗中的价值,文章主要介绍了PTP-1B的研究现状及其引起肥胖症的可能机制。  相似文献   

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Activation of NLRP3 inflammasome is precisely controlled to avoid excessive activation. Although multiple molecules regulating NLRP3 inflammasome activation have been revealed, the checkpoints governing NLRP3 inflammasome activation remain elusive. Here, we show that activation of NLRP3 inflammasome is governed by GSTO1-promoted ASC deglutathionylation in macrophages. Glutathionylation of ASC inhibits ASC oligomerization and thus represses activation of NLRP3 inflammasome in macrophages, unless GSTO1 binds ASC and deglutathionylates ASC at ER, under control of mitochondrial ROS and triacylglyceride synthesis. In macrophages expressing ASCC171A, a mutant ASC without glutathionylation site, activation of NLRP3 inflammasome is GSTO1 independent, ROS independent, and signal 2 less dependent. Moreover, AscC171A mice exhibit NLRP3-dependent hyperinflammation in vivo. Our results demonstrate that glutathionylation of ASC represses NLRP3 inflammasome activation, and GSTO1-promoted ASC deglutathionylation at ER, under metabolic control, is a checkpoint for activating NLRP3 inflammasome.  相似文献   

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As2O3对K562细胞BCR/ABL蛋白酪氨酸磷酸化的影响   总被引:22,自引:1,他引:22  
目的 进一步阐明As2O3 诱导K562 细胞凋亡和抑制其生长的可能机制,为As2O3 在临床上的应用提供理论依据。方法 采用免疫沉淀、Western blot、生物化学及免疫荧光等方法研究了As2O3对BCR/ABL蛋白酪氨酸磷酸化及其所介导的信号途径和某些凋亡相关蛋白表达的影响。结果 1μmol/LAs2O3 使细胞内多种蛋白酪氨酸磷酸化减少,而且BCR/ABL蛋白自身酪氨酸磷酸化亦减少,但0 .1 μmol/LAs2O3 对蛋白酪氨酸磷酸化的影响不明显;As2O3 对蛋白酪氨酸磷酸酶(PTP) 活性未见明显影响;As2O3 下调JAK2 蛋白的表达,但对STAT1 和STAT2 蛋白的表达以及STAT1 蛋白酪氨酸磷酸化无影响;As2O3 亦不影响凋亡相关蛋白Bcl2、BclxL/S、Bax、ICH1L、p53、PARP的表达,As2O3 亦使K562 细胞的PML蛋白降解。结论 As2O3 可能通过减少细胞内某些蛋白,尤其是BCR/ABL蛋白酪氨酸磷酸化和( 或)下调JAK2 蛋白的表达而干扰BCR/ABL致癌信号的传导,引起K562 细胞凋亡和抑制其生长。  相似文献   

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目的研究谷氨酸脱羧酶抗体(GAD—Ab)和蛋白酪氨酸磷酸酶-2抗体(IA-2A)检测的标准化,为合理选择检测方法及准确判定结果提供依据。方法应用国际糖尿病免疫学会(IDS)推荐的WHO单位制,采用放射配体法检测125名健康人的GAD—Ab和IA-2A以确定阳性判断标准,通过检测IDS第3次糖尿病自身抗体标准化检测方法评估(DASP 2003)工作组提供的100名健康对照及50例新发1型糖尿病患者血清,验证其灵敏度与特异性。并采用新一代的ELISA试剂盒检测41例已知抗体滴度的标本,对比ELISA与标化后放射配体法的一致性。结果GAD—Ab的阳性阈值为18.5U/ml,IA-2A为2.7U/ml。DASP 2003反馈结果显示,本室GAD—Ab检测的灵敏度82%,特异性98%;IA-2A检测的灵敏度64%,特异性100%;受试者工作特征(ROC)曲线分析显示,本室GAD-Ab曲线下面积(AUC)以及统一按95%特异性标化后的灵敏度(AS95)分别为0.946%及86%,IA-2A分别为0.824%及68%。在52个回报结果的实验室中综合排名第15位。ELISA试剂盒与标化后的放射配体法检测GAD—Ab的一致率82.9%,Kappa值0.656;检测IA-2A的一致率75.6%,Kappa值0.514;结果判定不一致者多集中在阳性边缘水平的标本中。结论经标准化后的GAD—Ab和IA-2A放射配体法灵敏度和特异性明显提高;新一代ELISA试剂盒检测GAD—Ab和IA-2A可应用于临床,但对于检测结果阴性而临床可疑者,建议采用放射配体检测法核实。  相似文献   

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Twelve new compounds, aspergorakhins A–L (1–12) coupled with one known xanthone leptosphaerin D (13), were isolated from the extract of soil-derived fungus Aspergillus gorakhpurensis F07ZB1707. Their structures were elucidated by spectroscopic data analysis including UV, IR, NMR, and HRESIMS. The absolute configurations of 5 and 8–11 were identified using ECD and OR calculations. All compounds were tested by enzyme inhibitory activity assay in vitro. Aspergorakhin A (1) showed selective activities against PTP1B and SHP1 over TCPTP with IC50 values 0.57, 1.19, and 22.97 μM, respectively. Compounds 1 and 2 exhibited modest cytotoxicity against tumor cell lines A549, HeLa, Bel-7402, and SMMC-7721 with IC50 values in the range of 6.75–83.4 μM.

Twelve novel metabolites were isolated from Aspergillus gorakhpurensis F07ZB1707. Aspergorakhin A (1) showed selective activities against PTP1B and SHP1 over TCPTP with IC50 values of 0.57, 1.19, and 22.97 μM, respectively.  相似文献   

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