GENE THERAPY OF GLOMERULONEPHRITIS BY GENE TRANSFER OF CELL CYCLE-RELATED GENES.

近年来的研究表明，丝裂原激活蛋白激酶（MAPK）至少包括三个亚家族，即经典MAPK（也称为ERK）、应激激活蛋白激酶/c-Jun n-末端激酶（JNK）和p38激酶。tgf -b激活激酶(TAK)-1是一种新的MAPKKK，据报道可刺激p38K和/或JNK通路。为了阐明TAK1通路的功能作用，我们将其组成型活性形式（TAKdN）和阴性形式（TAKK63W）转染到LLCPK1细胞中。TAKdN抑制3h -胸苷的摄取，降低S期和G2/M期的百分比。TAKK63W改善了TGF-b对3h -胸腺嘧啶摄取的抑制作用以及S期和G2/M期的百分比。Western blot分析表明，过表达TAKdN可负性调节细胞周期蛋白D1水平。此外，TAKdN过表达抑制了cyclin D1启动子的活性。与此同时，经典的p42/44 mapk激活因子MKK1的组成活性增加了cyclin D1启动子活性和蛋白水平。过表达活性形式的MKK1增加3h -胸苷的摄取，而非活性形式的MKK1则减少摄取。综上所述，cyclin D1启动子活性和细胞周期进程受TAK1-MKK6-p38K通路的负调控，而受MKK1-p42/44 MAPK通路的正调控。

Recent studies have revealed that mitogen-actiated protein kinase(MAPK)consists of at least three subfamilies, namely include classical MAPK(also known as ERK), stress-activated protein kinase/c-Jun N-terminal kinase(JNK), and p38 kinase. TGF-b-activating kinase(TAK)-1 is a novel MAPKKK which is reported to stimulate p38K and/or JNK pathway. To elucidate functional roles of the TAK1 pathway, we transfected its constitutive active form(TAKdN)and negative form(TAKK63W)to LLCPK1 cells. TAKdN inhibited 3H-thymidine uptake, and reduced the percentages of S and G2/M phases. TAKK63W ameliorated inhibition of 3H-thymidine uptake and the percentages of S and G2/M phases by TGF-b. Western blot analysis demonstrates that the cyclin D1 protein level was negatively regulated by overexpression of TAKdN.Moreover, overexpression of TAKdN inhibited cyclin D1 promoter activity. In contract, constitutive active MKK1, the classical p42/44 MAPK-activator, increased cyclin D1 promoter activity and protein level. Overexpression of the active form of MKK1 increased 3H-thymidine uptake, while the inactive form decreased the uptake.In conclusion, cyclin D1 promoter activity and cell cycle progression are negatively regulated by the TAK1-MKK6-p38K pathway and positively regulated by the MKK1-p42/44 MAPK pathway.