School of Engineering, Brown University, Providence, RI 02912, USA.
Department of Emergency Medicine, Alpert School of Medicine, Brown University, Providence, RI 02903, USA.
Int J Mol Sci. 2022 Apr 12;23(8):4245. doi: 10.3390/ijms23084245.
Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome leads to diarthrodial joint arthropathy and is caused by the absence of lubricin (proteoglycan 4-PRG4), a surface-active mucinous glycoprotein responsible for lubricating articular cartilage. In this study, mice lacking the orthologous gene served as a model that recapitulates the destructive arthrosis that involves biofouling of cartilage by serum proteins in lieu of Prg4. This study hypothesized that Prg4-deficient mice would demonstrate a quadruped gait change and decreased markers of mitochondrial dyscrasia, following intra-articular injection of both hindlimbs with recombinant human PRG4 (rhPRG4). (N = 44) mice of both sexes were injected with rhPRG4 and gait alterations were studied at post-injection day 3 and 6, before joints were harvested for immunohistochemistry for caspase-3 activation. Increased stance and propulsion was shown at 3 days post-injection in male mice. There were significantly fewer caspase-3-positive chondrocytes in tibiofemoral cartilage from rhPRG4-injected mice. The mitochondrial gene , and myosin heavy () and light chains ( and ), known to play a cytoskeletal stabilizing role, were significantly upregulated in both sexes (RNA-Seq) following IA rhPRG4. Chondrocyte mitochondrial dyscrasias attributable to the arthrosis in CACP may be mitigated by IA rhPRG4. In a supporting in vitro crystal microbalance experiment, molecular fouling by albumin did not block the surface activity of rhPRG4.
挛缩-关节病-髋内翻-心包炎(CACP)综合征导致关节性关节病,是由于缺乏润滑素(蛋白聚糖 4-PRG4)引起的,润滑素是一种负责润滑关节软骨的表面活性黏蛋白糖蛋白。在这项研究中,缺乏同源基因的小鼠作为模型,重现了涉及软骨生物污垢的破坏性关节炎,而不是 PRG4。本研究假设 PRG4 缺乏的小鼠在双侧后肢关节内注射重组人 PRG4(rhPRG4)后,会表现出四肢着地步态改变和线粒体功能障碍标志物减少。(N = 44)雌雄小鼠均注射 rhPRG4,在关节内注射后第 3 天和第 6 天研究步态改变,然后采集关节进行 caspase-3 激活的免疫组织化学检测。雄性小鼠在注射后第 3 天表现出明显的站立和推进增加。rhPRG4 注射小鼠的胫股软骨中 caspase-3 阳性软骨细胞明显减少。线粒体基因 和肌球蛋白重链(和)和轻链(和),已知在细胞骨架稳定中发挥作用,在雌雄两性(RNA-Seq)中均显著上调,随后进行 IA rhPRG4。IA rhPRG4 可能减轻 CACP 性关节炎中的软骨细胞线粒体功能障碍。在一项支持的体外晶体微天平实验中,白蛋白的分子污垢不会阻止 rhPRG4 的表面活性。