Fig. 6: Induction of the UPR^mt in cartilage tissues from OA patients.

a qPCR analysis of the expression of UPR^mt markers in the cartilage tissues of patients in the different groups. *p < 0.05, **p < 0.01, ***p < 0.001; n = 20. b Patients were divided into two subgroups based on the mRNA levels of UPR^mt markers that were higher or lower than 2 SDs from the mean for each transcript in the control group, and mRNA levels of UPR^mt markers in the different groups are shown. *p < 0.05, **p < 0.01, ***p < 0.001; n = 9–20. c–e Comparison of the clinical characteristics between OA patients with lower or higher UPR^mt markers. c WOMAC scores of pain. d Total ICOAP scores. e VAS scores at rest and walking; *p < 0.05, n = 9–11. f–h Measurement of chondrocyte apoptosis and inflammation levels in the cartilage tissue and synovial fluid of OA patients with lower or higher UPR^mt marker levels. f TUNEL + chondrocytes, g IL-1β levels, and (h) TNF-α levels. *p < 0.05, **p < 0.01, ***p < 0.001; n = 9–11. i Schematic of the hypothesized mechanism of the UPR^mt in OA.