Involvement of the RhoA/ROCK signaling pathway in the pathogenesis of knee osteoarthritis

Purpose This study compared the expression of the Ras homolog gene family member A (RhoA) and Rho-associated coiled-coil kinase (ROCK) signaling pathway members in knee joint synovial tissue from patients with primary knee osteoarthritis (KOA) who underwent lower limb disarticulation. Methods The specimens were separated into observation (synovial tissue removed during total knee arthroplasty of 30 patients with primary KOA) and control groups (synovial tissue removed during lower limb disarticulation of 25 patients). Results The observation group specimens showed high proliferation, congestion, edema, unorganized cellular arrangement, and presence of vacuolated cells. The control group specimens were white with a smooth surface and non-edematous texture, and showed organized and homogenous cell/stroma arrangement. The observation group showed higher expression of RhoA and ROCK transcripts and proteins than the control. Conclusion Patients with KOA expressed high levels of RhoA and ROCK transcripts and proteins in synovial tissues, suggesting a relationship between RhoA/ROCK and KOA. Our findings provide a potential therapeutic target for delaying synovial lesions in KOA.