Journal: Experimental & Molecular Medicine

Article Title: The mitochondrial unfolded protein response (UPR mt ) protects against osteoarthritis

doi: 10.1038/s12276-022-00885-y

Figure Lengend Snippet: a Compared with control chondrocytes, chondrocytes treated with NR (1 mmol/l) showed increased mRNA levels of Hsp10, Hsp60, mtDNAj, Atf5, ClpP, and LonP1. ** p < 0.01, *** p < 0.001; NS = not significant; n = 3. b Electron micrographs of chondrocytes showing intact mitochondria (white arrow, control, and IL-1β + NR groups) with well-preserved double membranes and cristae structures and fragmented mitochondria (black arrow, IL-1β group) with deformed or absent cristae structures. Scale bar, 500 nm. c – f Mitochondrial respiratory chain complex I–IV activity in chondrocytes treated with IL-1β. * p < 0.05, ** p < 0.01 compared with the control group; NS = not significant; n = 3. g Flow cytometric analysis of JC‑1 distribution in chondrocytes. h The JC-1 ratio was calculated as the number of green JC-1-positive mitochondria relative to the number of red JC-1-positive mitochondria. ** p < 0.01; n = 3.

Article Snippet: After the supernatants were incubated with JC-1 (0.5 μmol/L, Invitrogen) for 20 min at 37 °C, the samples were precipitated by centrifugation at 600 × g and 4 °C for 3 min. Primary mouse chondrocytes were washed twice with JC-1 staining buffer and centrifuged at 4 °C for 3 min to pellet the cells.

Techniques: Activity Assay