Fig. 6.

PA28γ knockdown inhibits endoplasmic reticulum (ER) stress in chondrocytes by promoting signal transducer and activator of transcription 3 (STAT3) phosphorylation. a) Representative western blotting and quantitative data of COX2, BAX, BCL2, GRP78, and CHOP after transfection of chondrocytes with si-NC or si-PA28γ and treatment with tert-butylhydrogen peroxide (TBHP) (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001). b) Representative western blotting and quantitative data of STAT3 and p STAT3 after transfection of chondrocytes with si-NC or si-PA28γ and treatment with TBHP, **p < 0.01. c) Representative western blotting and quantitative data of STAT3 and p-STAT3 after treatment with TBHP and Stattic (***p < 0.001). d) Representative western blotting and quantitative data of GRP78 and CHOP after transfection of chondrocytes with si-NC or si-PA28γ and treatment with TBHP and Stattic (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001). e) CHOP representative immunofluorescence images of chondrocytes transfected with si-NC or si-PA28γ and treated with TBHP and Stattic, measuring scale = 100 μm, magnification: ×200. DAPI, 4′,6-diamidino-2-phenylindole; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; ns, not significant.