Fig. 7

Pathway of STAT3 inhibition in improvement muscle atrophy in the PAH model. A, B The expression of indicated proteins in gastrocnemius muscles was detected by western blot. The band intensities were quantified and total STAT3 or GAPDH was used as control. C Model depicting how STAT3 promotes GDF11-induced muscle wasting. The GDF11 binds to ACVR2B/ALK5 and then activates STAT3 via phosphorylation. Following p-STAT3 translocates to the nucleus and upregulates the expression of iNOS and socs3, leading to the activation of the ubiquitin-proteasome pathway and iNOS/NO pathway, which in turn promotes muscle wasting. Data are shown as mean ± SEM. Versus vehicle control, *P < 0.05, **P < 0.01, ***P < 0.001; versus MCT control, ^#P < 0.05, ^##P < 0.01, ^###P < 0.001; n=3 rats