Kartogenin potentially protects temporomandibular joints from collagenase-induced osteoarthritis via core binding factor β and runt-related transcription factor 1 binding - A rat model study

Temporomandibular joint (TMJ) osteoarthritis (TMJOA) is a chronic disease with progressive destruction of articular cartilage. This study aimed to explore the therapeutic effects of kartogenin on TMJOA via promoting the binding of core binding factor β (CBFβ) and runt-related transcription factor 1 (RUNX1).Type II collagenase was injected into 35 8-week-old male Sprague Dawley rat TMJs to establish the TMJOA model. Kartogenin, or the CBFβ-RUNX1 complex inhibitor (Ro5-3335), was also delivered via intra-articular injection. Subchondral bone was analyzed by MicroCT. The hematoxylin-eosin, Safranin O, and toluidine blue O staining were used to observe histopathology. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA), caspase-3 (CASP3), interleukin-1β (IL-1β), and collagen II (COL2) was performed.TMJOA was established in rats by intra-articular injection of type II collagenase. The condylar cartilage and subchondral bone were damaged, with decreased PCNA and COL2 and increased CASP3 and IL-1 (P < .001). Compared with the OA group, kartogenin alleviated the destruction of cartilage and subchondral bone, rescued the expression of PCNA and COL2, and decreased the expression of CASP3 and IL-1β (P < .01). Ro5-3335 did not aggravate the pathology of TMJOA but neutralized the therapeutic effects of kartogenin on TMJOA.Kartogenin has a potential therapeutic effect on TMJOA via promoting the CBFβ-RUNX1 binding.