C1q/TNF-related protein-9 suppresses inflammation in synovial cells from patients with osteoarthritis

CTRP9 may have therapeutic potential for treating OA. Osteoarthritis (OA) is characterized as cartilage destruction resulting from synovial inflammation (1-6). According to the clinical symptoms and levels of inflammation, OA has been divided into primary generalized osteoarthritis (PGOA) and erosive inflammatory osteoarthritis (EIOA) (7). The only available treatment for OA is joint replacement. Thus, it is necessary to develop novel and effective therapeutic strategies to treat OA. Because synovial inflammation contributes to OA development, targeting the inflammation process may provide a promising strategy for OA treatment. Previous investigations showed that pro-inflammatory factors promoted OA development (8-10), while anti-inflammatory factors suppressed it (11-14). Thus, we conducted the present study to investigate the role of C1q/tumour necrosis factor-related protein-9 (CTRP9), an anti-inflammatory factor (15), in OA, and its therapeutic potential.