FIGURE 3

Sirt1 and the UPR^mt enhance the mFAO to preserve muscle integrity during muscle atrophy. (a) qRT-PCR analysis of the skeletal muscle from DEXA-treated adult zebrafish showing the expression of the mitochondrial fatty acid oxidation (mFAO) genes cpt1b, acadm, acsf2, and acat1 (*p < 0.05, t-test, two-tailed, error bar indicates s.d.). (b) qRT-PCR analysis of wild-type or the ubl5 knockdown (ubl5-mo) zebrafish larvae treated with DEXA showing the DEXA-induced fold increase of the UPR^mt genes hspd1, hspa9, lonp1, and clpp (*p < 0.05, t-test, two-tailed, error bar indicates s.d.). (c) qRT-PCR analysis of wild-type or the ubl5 knockdown (ubl5-mo) zebrafish larvae treated with DEXA showing the expression of cpt1b (*p < 0.05, t-test, two-tailed, error bar indicates s.d.). (d) Representative confocal microscopy images of Alexa488-phalloidin-stained wild-type, the sirt1 mutant, and the ubl5 knockdown (ubl5-mo) zebrafish larvae treated with DEXA. Boxplot shows quantification of larvae with 0, 1–6, or ≥ 7 detached muscle fibers (*p < 0.05, Chi-square test. Arrows indicate examples of detached muscle fibers. Scale bar represents 50 µM).