摘要
背景:在诸多老化和衰老的研究中,p16INK4a是研究较多的一种产物,然而其在与衰老密切相关的骨性关节炎中的研究较少。目的:观察p16INK4a在正常和骨性关节炎软骨细胞中的表达,讨论其在骨性关节炎病理过程中的作用。设计:以诊断为依据设立对照的实验研究。地点和对象:实验在北京大学第三医院骨科完成,对象为骨性关节炎软骨标本,取材于在北京大学第三医院骨科手术的膝骨关节炎患者。正常老年、中年及青年组软骨标本分别取自无骨性关节炎患者。干预:直接从软骨组织中提取蛋白和细胞的总RNA,分别进行Westernblot和RT-PCR分析,检测p16INK4a在年轻、中年、正常老年人及骨性关节炎患者软骨中的表达情况。对p16INK4a下游底物pRb的磷酸化状态也进行了蛋白表达的分析。主要观察指标:p16INK4a在蛋白水平及mRNA水平上的表达。结果:在关节软骨细胞中,p16INK4a的表达随着年龄的增长,其表达量也逐渐增多;相应地,p16INK4a的主要靶物质pRb的磷酸化明显减少,相反非磷酸化的pRb的含量则相对增高。与正常人相比,这些变化在骨性关节炎的软骨细胞中尤为显著。结论:p16INK4a/pRb途径可能在关节软骨细胞的老化及骨性关节炎的发病过程中具有一定的调节作用。
BACKGROUND:Intensive studies of p16INK4a has been carried on in the research o f aging, but its role in the pathogenesis of osteoarthritis(OA), which is closel y related to aging, has not been thoroughly examined.OBJECTIVE:To determine the expression of p16INK4a in human articular chondrocy tes for understanding its possible role in the pathogenesis of OA.DESIGN:A controlled experiment was conducted on the basis of clinical diagnosi s.SETTING and PARTICIPANTS: All samples were obtained from the patients undergoi ng surgery in the Department of Orthopeadic Surgery, Third Hospital of Peking Un iversity. Osteoarthritic cartilage samples were from 26 senior patients undergoi ng total knee replacement. Also collected were the normal cartilage samples from 13 age-matched subjects, 17 young and 13 middle-ged subjects, who exhibited n o clinical signs of OA. INTERVENTIONS: The total RNA was extracted from the chondrocytes of the OA pat ients and healthy young, middle-aged and senior subjects for determination of p 16INK4a protein and mRNA expressions by means of Western blotting and reverse tr anscriptase-PCR(RT-PCR) respectively.Phosphorylation status of pRb, an establi shed target of p16INK4a, was also examined by Western blotting.MAIN OUTCOME MEASURES:The expressions of p16INK4a protein and mRNA levels were measured.RESULTS:p16INK4a expression in the chondrocytes tended to increase with age, b ut no significant difference in its expressions was found between senior and mid dle-aged control subjects. OA patients, in contrast, had significantly increase d p16INK4a expressions, and accordingly, loss of phosphorylated pRb and elevated levels of unphosphorylated pRb were observed in these patients. CONCLUSION:Alterations of p16INK4a/pRb pathway may be involved in the aging of the chondrocytes and pathogenesis of OA, in which processes p16INK4 overexpress ion and the subsequent loss of phosphorylated pRb play an important role.
出处
《中国临床康复》
CSCD
2004年第11期2148-2149,共2页
Chinese Journal of Clinical Rehabilitation
