SMURF2(smad ubiquitination regulatory factor 2)属于HECT(homologous to E6AP C terminus)家族E3泛素连接酶,有研究报道SMURF2在不同类型癌症中发挥促癌或抑癌作用.本研究探讨了SMURF2在前列腺(癌)细胞中调节STAT1(signal transducer...SMURF2(smad ubiquitination regulatory factor 2)属于HECT(homologous to E6AP C terminus)家族E3泛素连接酶,有研究报道SMURF2在不同类型癌症中发挥促癌或抑癌作用.本研究探讨了SMURF2在前列腺(癌)细胞中调节STAT1(signal transducers and activators of transcription 1)蛋白的分子机制.首先通过数据库分析SMURF2在正常组织与肿瘤组织间的表达差异,然后选取前列腺正常细胞和多种前列腺癌细胞为实验材料,通过RT-PCR,Western blotting实验检测SMURF2在前列腺(癌)细胞中的表达水平,发现相对于前列腺正常细胞,SMURF2在前列腺癌细胞中表达更高.再通过Co-IP,免疫荧光和泛素化检测实验观察SMURF2对STAT1蛋白泛素化水平的影响,发现SMURF2可以增加STAT1蛋白的泛素化水平,并进一步促进前列腺癌细胞发生EMT(epithelial mesenchymal transformation).展开更多
Transforming growth factor-β(TGF-β)and bone morphogenetic protein(BMP)play important roles in bone metabolism.Smad ubiquitination regulatory factors(Smurfs)regulate TGF-β/BMP signaling via ubiquitination,resulting ...Transforming growth factor-β(TGF-β)and bone morphogenetic protein(BMP)play important roles in bone metabolism.Smad ubiquitination regulatory factors(Smurfs)regulate TGF-β/BMP signaling via ubiquitination,resulting in degradation of signaling molecules to prevent excessive activation of TGF-β/BMP signaling.Though Smurf2 has been shown to negatively regulate TGF-β/Smad signaling,its involvement in BMP/Smad signaling in bone metabolism has not been thoroughly investigated.In the present study,we sought to evaluate the role of Smurf2 in BMP/Smad signaling in bone metabolism.Absorbable collagen sponges containing 3μg of recombinant human BMP2(rhBMP2)were implanted in the dorsal muscle pouches of wild type(WT)and Smurf2−/−mice.The rhBMP2-induced ectopic bone in Smurf2−/−mice showed greater bone mass,higher mineral apposition and bone formation rates,and greater osteoblast numbers than the ectopic bone in WT mice.In WT mice,the ectopic bone consisted of a thin discontinuous outer cortical shell and scant inner trabecular bone.In contrast,in Smurf2−/−mice,the induced bone consisted of a thick,continuous outer cortical shell and abundant inner trabecular bone.Additionally,rhBMP2-stimulated bone marrow stromal cells(BMSCs)from Smurf2−/−mice showed increased osteogenic differentiation.Smurf2 induced the ubiquitination of Smad1/5.BMP/Smad signaling was enhanced in Smurf2−/−BMSCs stimulated with rhBMP2,and the inhibition of BMP/Smad signaling suppressed osteogenic differentiation of these BMSCs.These findings demonstrate that Smurf2 negatively regulates BMP/Smad signaling,thereby identifying a new regulatory mechanism in bone metabolism.展开更多
文摘SMURF2(smad ubiquitination regulatory factor 2)属于HECT(homologous to E6AP C terminus)家族E3泛素连接酶,有研究报道SMURF2在不同类型癌症中发挥促癌或抑癌作用.本研究探讨了SMURF2在前列腺(癌)细胞中调节STAT1(signal transducers and activators of transcription 1)蛋白的分子机制.首先通过数据库分析SMURF2在正常组织与肿瘤组织间的表达差异,然后选取前列腺正常细胞和多种前列腺癌细胞为实验材料,通过RT-PCR,Western blotting实验检测SMURF2在前列腺(癌)细胞中的表达水平,发现相对于前列腺正常细胞,SMURF2在前列腺癌细胞中表达更高.再通过Co-IP,免疫荧光和泛素化检测实验观察SMURF2对STAT1蛋白泛素化水平的影响,发现SMURF2可以增加STAT1蛋白的泛素化水平,并进一步促进前列腺癌细胞发生EMT(epithelial mesenchymal transformation).
文摘目的观察不同浓度高糖刺激后大鼠肾小球系膜细胞胞内Smad泛素调节因子2(Smurf2)的表达,探讨泛素化降解在糖尿病肾病中的作用。方法将体外培养的大鼠肾系膜细胞分别设正常对照组(葡萄糖浓度5.6 mmol/L)、20 mmol/L高糖组、30 mmol/L高糖组、甘露醇组。分别用real ti me quantitative PCR法和细胞免疫荧光染色法及激光共聚焦显微镜检测各组细胞Smurf2的mRNA和蛋白的表达。结果(1)正常对照组系膜细胞Smurf2的mRNA和蛋白表达较弱。(2)高糖组Smurf2的mRNA和蛋白表达较正常对照组增强(P<0.05),呈浓度依赖性。结论高糖可诱导肾系膜细胞Smurf2表达增强。提示泛素-蛋白酶体途径可能参与了糖尿病肾病的病理进程。
基金the JSPS Grant-in-Aid(C)grant number 17K11005the JSPS bilateral Joint Research Project grant number 1007397 to T.K.,MEXT/JSPS grant number JP19K12218 to T.S.,MEXT/JSPS grant number JP15H05952(“Resonance Bio”)to T.S.and T.I.,and MEXT/JSPS KAKENHI grant number JP16H06280(“Advanced Bioimaging Support”)。
文摘Transforming growth factor-β(TGF-β)and bone morphogenetic protein(BMP)play important roles in bone metabolism.Smad ubiquitination regulatory factors(Smurfs)regulate TGF-β/BMP signaling via ubiquitination,resulting in degradation of signaling molecules to prevent excessive activation of TGF-β/BMP signaling.Though Smurf2 has been shown to negatively regulate TGF-β/Smad signaling,its involvement in BMP/Smad signaling in bone metabolism has not been thoroughly investigated.In the present study,we sought to evaluate the role of Smurf2 in BMP/Smad signaling in bone metabolism.Absorbable collagen sponges containing 3μg of recombinant human BMP2(rhBMP2)were implanted in the dorsal muscle pouches of wild type(WT)and Smurf2−/−mice.The rhBMP2-induced ectopic bone in Smurf2−/−mice showed greater bone mass,higher mineral apposition and bone formation rates,and greater osteoblast numbers than the ectopic bone in WT mice.In WT mice,the ectopic bone consisted of a thin discontinuous outer cortical shell and scant inner trabecular bone.In contrast,in Smurf2−/−mice,the induced bone consisted of a thick,continuous outer cortical shell and abundant inner trabecular bone.Additionally,rhBMP2-stimulated bone marrow stromal cells(BMSCs)from Smurf2−/−mice showed increased osteogenic differentiation.Smurf2 induced the ubiquitination of Smad1/5.BMP/Smad signaling was enhanced in Smurf2−/−BMSCs stimulated with rhBMP2,and the inhibition of BMP/Smad signaling suppressed osteogenic differentiation of these BMSCs.These findings demonstrate that Smurf2 negatively regulates BMP/Smad signaling,thereby identifying a new regulatory mechanism in bone metabolism.
