Fig. 1: Induction of the UPRmt in stressed primary mouse chondrocytes and the cartilage of OA mice.
From: The mitochondrial unfolded protein response (UPRmt) protects against osteoarthritis
a, b Response of chondrocytes to IL-1β (5, 10, or 20 ng/ml for 24 h or 10 ng/ml for 12, 24, or 48 h). c, d Response of chondrocytes to valinomycin (2.5, 5, or 7.5 μM for 2 h or 5 μM for 2, 4, or 6 h). e, f Response of chondrocytes to rotenone (50, 100, or 150 ng/ml for 1 h or 50 ng/ml for 1, 2, or 4 h). *p < 0.05, differences in the mRNA levels of UPRmt markers compared with those in the control group; n = 3. g Representative images of mouse knee joints stained with safranin-O/fast green in the sham group and DMM surgery group (8 weeks after surgery). Black arrows indicate articular cartilage degradation; scale bar, 100 mm. h Expression of UPRmt markers in the cartilage of DMM-induced OA mice; *p < 0.05 compared with the sham group; n = 6. Hsp10 = Heat shock 10 kDa protein 1; Hsp60 = Heat shock 60 kDa protein 1; mtDNAj = mitochondrial presequence translocase-associated motor complex protein; Atf5 = cyclic AMP-dependent transcription factor ATF5; ClpP = ATP-dependent Clp protease proteolytic subunit; LonP1 = Lon protease homolog; UPRmt = mitochondrial unfolded protein response.
