[JAK2/STAT3 signal pathway mediating curcumin in cartilage cell metabolism of osteoarthritis]

To observe influence of JAK2/STAT3 signal pathway mediating curcumin in cartilage cell metabolism of osteoarthritis and mitochondria oxidative stress resistance;also explore the role of JAK2/STAT3 signal pathway and effect of curcumin in this process.

Fifteen male SPF C57BL/6 rats rweighted from 10.05 to 15.00 g with an average of 12.80 g were collected and randomly divided into control group, OA group(modeled as OA by Glasson SS), curcumin with OA group (100 mg/kg curcumin were performed intraperitoneal injection every day based on OA group), 5 rats in each group. Rats were taken off the neck after 4 weeks, morphologic change were observed, specimens changes were observed by histochemical methods;p-JAK2, p-STAT3 and Bax protein expression were detected by Western blot;At the same time, the changes of mitochondria oxidative stress index such as succinate dehydrogenase(SDH) and cytochrome C oxydase(COX) in each group were detected.

After 4 weeks, cartilage tissue showed translucent shape, no swelling and congestion, the number of cartilage cell increased, nuclei liked oval, chromatin arranged uniform in control group;in curcumin with OA group, joint showed slightly swelling without congestion, the formation of cartilage cell was regular, and number of cell decreased;while in OA group, the surface of joint was roughness with mild damage, cell arrangement was a bit disorder, nuclear was disappeared under vision and dyeing was uneven. Compared with control group, p-JAK2, p-STAT3 protein expression was decreased in OA and curcumin with OA group(P<0.05), Bax protein expression was increased (P<0.05), SDA and COX protein expression were reduced (P<0.05). Compared with OA group, p-JAK2, p-STAT3 protein expression was increased in curcumin with OA, Bax protein expression was decreased (P<0.05), SDA and COX protein expression were increased (P<0.05), and had statistical differences among three groups.

JAK2/STAT3 signal pathway is closely associated with pathology course of osteoarthritis, curcumin could stimulate JAK2/STAT3 signal pathway and promote mitochondria oxidative stress. It could obviously relieve degeneration of articular cartilage and slow lower progress of OA.