First Author | Kozijn AE | Year | 2019 |
Journal | Osteoarthritis Cartilage | Volume | 27 |
Issue | 1 | Pages | 118-128 |
PubMed ID | 30248505 | Mgi Jnum | J:327644 |
Mgi Id | MGI:7333253 | Doi | 10.1016/j.joca.2018.09.007 |
Citation | Kozijn AE, et al. (2019) Human C-reactive protein aggravates osteoarthritis development in mice on a high-fat diet. Osteoarthritis Cartilage 27(1):118-128 |
abstractText | OBJECTIVE: C-reactive protein (CRP) levels can be elevated in osteoarthritis (OA) patients. In addition to indicating systemic inflammation, it is suggested that CRP itself can play a role in OA development. Obesity and metabolic syndrome are important risk factors for OA and also induce elevated CRP levels. Here we evaluated in a human CRP (hCRP)-transgenic mouse model whether CRP itself contributes to the development of 'metabolic' OA. DESIGN: Metabolic OA was induced by feeding 12-week-old hCRP-transgenic males (hCRP-tg, n = 30) and wild-type littermates (n = 15) a 45 kcal% high-fat diet (HFD) for 38 weeks. Cartilage degradation, osteophytes and synovitis were graded on Safranin O-stained histological knee joint sections. Inflammatory status was assessed by plasma lipid profiling, flow cytometric analyses of blood immune cell populations and immunohistochemical staining of synovial macrophage subsets. RESULTS: Male hCRP-tg mice showed aggravated OA severity and increased osteophytosis compared with their wild-type littermates. Both classical and non-classical monocytes showed increased expression of CCR2 and CD86 in hCRP-tg males. HFD-induced effects were evident for nearly all lipids measured and indicated a similar low-grade systemic inflammation for both genotypes. Synovitis scores and synovial macrophage subsets were similar in the two groups. CONCLUSIONS: Human CRP expression in a background of HFD-induced metabolic dysfunction resulted in the aggravation of OA through increased cartilage degeneration and osteophytosis. Increased recruitment of classical and non-classical monocytes might be a mechanism of action through which CRP is involved in aggravating this process. These findings suggest interventions selectively directed against CRP activity could ameliorate metabolic OA development. |