Cell cycle regulation for treatment of rheumatoid arthritis

Objective.在滑膜组织中强制表达细胞周期蛋白依赖性激酶抑制剂（CDKI）基因、p16 INK 4a或p21 Cip 1对类风湿关节炎（RA）动物模型有治疗作用。虽然CDKI的主要功能是阻止细胞周期进展，但它们的抗增殖作用伴随着治疗关节中炎症的抑制。随后，我们和其他人发现p21 Cip 1不仅抑制CDKs的活性，而且下调c-Jun N-末端激酶（JNK）和其他细胞内信号通路。尽管缺乏p16 INK 4a与其他分子相互作用的可靠证据，但p16 INK 4a抑制类风湿性滑膜成纤维细胞（RSF）产生的特异性炎症分子。由于这些分子中的一些是p16 INK 4a和p21 Cip 1的作用所共有的，因此研究了CDK 4/6活性对其产生的直接影响。方法. CDKIs基因，p16 INK 4a和p18 INK 4c，视网膜母细胞瘤基因的组成型活性，低磷酸化形式 关于我们 用腺病毒介导法将Rb蛋白、细胞周期蛋白D1和CDK 4导入RSF中，调节CDK 4/6的活性。使用合成的CDK 4/6抑制剂来抑制CDK 4/6。3 H-TdR掺入法和流式细胞术检测细胞周期。用北方印迹分析、实时聚合酶链反应和/或ELISA测定基质金属蛋白酶（MMP）-3、单核细胞趋化蛋白（MCP）-1或I型白细胞介素1受体（IL-1 R1）的表达水平。免疫沉淀CDKIs以揭示其与JNK的关联。结果p16 INK 4a和p18 INK 4c基因转移抑制细胞周期进程，并抑制MMP-3和MCP-1的产生。与p21 Cip 1不同，这两种分子都不抑制IL-1 R1表达或与JNK结合。通过合成的CDK 4/6抑制剂抑制CDK 4/6也下调这些炎症介质。当CDK 4活性增强时，它们被上调。这种调节作用在MMP-3的mRNA水平，但不为MCP-1。转移活性Rb，这模仿抑制CDK依赖的Rb磷酸化，抑制生产，而不改变它们的mRNA水平。结论.在RSF中抑制CDK 4/6下调MCP-1和MMP-3的产生，其通过增强CDK 4活性而上调。MMP-3的产生主要由激酶活性在mRNA水平上以Rb非依赖的方式调节，而MCP-1的产生由Rb在转录后控制。少

Objective. Forced expression of cyclin-dependent kinase inhibitor (CDKI) gene, p16INK4a or p21Cip1 in the synovial tissues was effective in treating animal models of rheumatoid arthritis (RA). Although the primary function of CDKIs is halting cell cycle progression, their anti-proliferative effect accompanied suppression of inflammation in the treated joints. Subsequently, we and others found that p21 Cip1 does not only inhibit activitity of CDKs but downmodulates c-Jun N-terminal kinase (JNK) and other intracellular signaling pathways. Despite lack of solid evidence for interaction of p16INK4a with other molecules, p16INK4a suppressed specific inflammatory molecules produced by rheumatoid synovial fibroblasts (RSF). Since, some of these molecules were shared by the effects of p16INK4a and p21 Cip1, direct effects of CDK4/6 activity on their production were studied. Methods. Genes for CDKIs, p16INK4a and p18INK4c, a constitutively active, hypophosphorylated form of retinoblastoma gene … More product (Rb), cyclin D1 and CDK4 were transferred into RSF with adenoviruses to modulate CDK4/6 activity. A synthetic CDK4/6 inhibitor was used to inhibit CDK4/6. Cell cycle was studied with 3H-thymidine incorporation and flow cytometry. Expression levels of matrix metalloproteinase (MMP)-3, monocyte chemoattaractant protein (MCP)-1 or type I interleukin 1 receptor (IL-1R1) was determined with Northern blot analyses, real-time polymerase chain reaction, and/or ELISAs. CDKIs were immunoprecipitated to reveal their association with JNK. Results. Gene transfer of p16INK4a as well as p18INK4c inhibited cell cycle progression and suppressed MMP-3 and MCP-1 production. Unlike p21Cip1, neither molecules inhibit IL-1 R1 expression or bind to JNK. Inhibition of CDK4/6 by a synthetic CDK4/6 inhibitor also downregulated these inflammatory mediators. They were upregulated when CDK4 activity was augmented. This regulation functioned at the mRNA level for MMP-3, but not for MCP-1. Transfer of active Rb, which mimicked inhibition of CDK-dependent Rb phosphorylation, suppressed production of both without changing their mRNA levels. Conclusions. Inhibition of CDK4/6 in RSF downregulated MCP-1 and MMP-3 production, which was upregulated by augmented CDK4 activity. MMP-3 production was primarily regulated by the kinase activity at the mRNA level in an Rb-independent manner, while MCP-1 production was controlled posttranscriptionally by Rb. Less