Myostatin Activates the Ubiquitin-Proteasome and Autophagy-Lysosome Systems Contributing to Muscle Wasting in Chronic Kidney Disease

Figure 2

CKD upregulates the ubiquitin-proteasome and autophagy-lysosome systems in rat muscle. (a) Left: representative immunoblotting of Atg3, Atg7, Atg12, Beclin-1, LC3-I/II, and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH). Right: The ratio of Atg3, Atg7, Atg12, Beclin-1, LC3-II, and GAPDH normalized to the sham group. (b) Representative fluorescent images of LC3-II. LC3-II was marked in green and nuclei were labeled by DAPI staining in blue. Scale bar = 50 μm. (c) The caspase-like β1 activity, trypsin-like β2 activity, and chymotrypsin-like β5 activity of 26S in gastrocnemius muscle were measured after initiating the reaction with Z-LLE-AMC (β1), Boc-LSTR-AMC (β2), and Suc-LLVY-AMC (β5). (d) The expression of MAFbx and MuRF-1 mRNA was measured by RT-PCR and is presented as corrected for GAPDH and normalized to the sham group. (e) Upper: representative immunoblotting of MAFbx, MuRF1, and GAPDH. Lower: the ratio of MAFbx, MuRF1, and GAPDH normalized to the sham group. Values were described means, with SD represented by vertical bars. Significantly different (, independent experiments) from sham group.

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