Fig. 8.

CHOP knockdown in skeletal muscle cells had no impact on general UPR signaling. C₂C₁₂ cells were transfected with either 30 nM of scrambled (Scr) or CHOP siRNA (si-CHOP) on days 4 and 7 of differentiation. Chronic contractile activity (CCA) began on day 5 vs. control (CON) nonstimulated cells. A: representative blots of UPR^MT/ER markers. Graphical representations of UPR^ER markers ATF4 (B), BiP (C), and UPR^MT markers mtHSP70 (D), mtHSP60 (E), and Sirt3 (F). Data are expressed as means ± SE and are measured in arbitrary units (AU). *P < 0.05 main effect of CCA; φP < 0.05 main effect of CHOP siRNA; n = 4 to 7 experiments.