Aupperle K R, Boyle D L, Hendrix M, Seftor E A, Zvaifler N J, Barbosa M, Firestein G S
University of California, San Diego, School of Medicine, La Jolla 92093-0656, USA.
Am J Pathol. 1998 Apr;152(4):1091-8.
Recent studies show that 1) the p53 tumor suppressor protein is overexpressed by rheumatoid arthritis (RA) synovium and fibroblast-like synoviocytes (FLS) and 2) somatic mutations previously identified in human tumors are present in RA synovium and FLS. We have hypothesized that abnormalities in p53 can contribute to chronic destructive RA synovitis. To understand the functional consequences of p53 abnormalities in FLS, RA and normal FLS expressing wild-type p53 were transduced with a retroviral vector encoding the human papilloma virus 18 E6 gene, which inactivates endogenous p53 protein. Three RA and one normal FLS lines were infected with recombinant retrovirus encoding the neomycin resistance gene (neo) or E6+neo. FLS proliferation, apoptosis, and invasion was studied in E6, neo, and uninfected parental strains (PS). The growth rate for E6 was significantly increased with a sixfold increase in cell number after 7 days compared with a twofold to threefold increase in neo and PS. When FLS were treated with cytokines, proliferative response of E6, neo, and PS to interleukin-1 and transforming growth factor-beta were similar. However, response to platelet-derived growth factor was significantly greater in E6 FLS compared with neo or PS. Apoptosis was studied by incubating FLS with sodium nitroprusside as a source of nitric oxide or hydrogen peroxide for 8 hours and examining DNA fragmentation and E6 cells were significantly less susceptible to cell death. In addition, E6 FLS were more invasive into cartilage extracts than neo or PS using an in vitro cell invasion assay. These data suggest that p53 is a critical regulator of FLS proliferation, apoptosis, and invasiveness. Abnormalities of p53 function might contribute to synovial lining expansion and joint destruction in RA.
1）类风湿关节炎（RA）滑膜及成纤维样滑膜细胞（FLS）中p53肿瘤抑制蛋白过度表达；2）先前在人类肿瘤中鉴定出的体细胞突变存在于RA滑膜及FLS中。我们推测p53异常可能导致慢性破坏性RA滑膜炎。为了解FLS中p53异常的功能后果，用编码人乳头瘤病毒18 E6基因的逆转录病毒载体转导表达野生型p53的RA和正常FLS，该基因可使内源性p53蛋白失活。三个RA和一个正常FLS细胞系用编码新霉素抗性基因（neo）或E6 + neo的重组逆转录病毒感染。在E6、neo及未感染的亲代细胞株（PS）中研究FLS的增殖、凋亡及侵袭。E6的生长速率显著增加，7天后细胞数量增加6倍，而neo和PS仅增加2至3倍。当FLS用细胞因子处理时，E6、neo及PS对白细胞介素 - 1和转化生长因子 - β的增殖反应相似。然而，与neo或PS相比，E6 FLS对血小板衍生生长因子的反应明显更强。通过用硝普钠作为一氧化氮或过氧化氢的来源孵育FLS 8小时并检测DNA片段化来研究凋亡，E6细胞对细胞死亡的敏感性明显较低。此外，使用体外细胞侵袭试验，E6 FLS比neo或PS更易侵入软骨提取物。这些数据表明p53是FLS增殖、凋亡及侵袭性的关键调节因子。p53功能异常可能导致RA滑膜衬里扩张和关节破坏。
