Curcumin Inhibits the PERK-eIF2α-CHOP Pathway through Promoting SIRT1 Expression in Oxidative Stress-induced Rat Chondrocytes and Ameliorates Osteoarthritis Progression in a Rat Model

Figure 7

Curcumin inhibited apoptosis of chondrocytes and ER stress in the rat ACLT model. (a) The degenerative changes of articular cartilage in each group were assessed by X-ray imaging. The joint degenerative changes include the calcification of cartilage surface and the narrowing of knee joint space. (b) Histological analysis and microscopic observation of cartilage destruction in each group were evaluated at 8 weeks postsurgery by Safranin O staining and H&E staining (bar: 50 μm). The defects and destruction of cartilage surface indicated the osteoarthritis pathological changes of rat knee joint. Lesions of articular cartilage were indicated by black arrows. (c) Osteoarthritis Research Society International (OARIS) scores of articular cartilage in four groups as indicated. (d, e) TUNEL staining of apoptotic chondrocytes and quantitation of TUNEL staining in each group (bar: 50 μm). (f, g) IHC staining of cleaved caspase3, CHOP, and SIRT1 expression and the quantitation of the IHC staining in each group (bar: 50 μm). All results represent (). , . ACLT: anterior cruciate ligament transection; Low CUR: 50 mg/kg/day curcumin; High CUR: 150 mg/kg/day curcumin, IHC staining, immunohistochemical staining.

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