Fig. 4

Viral transductions or infections do not universally downregulate cell surface receptors. a. qRT-PCR in primary mouse myoblasts transduced in vitro with non-target GFP shRNA vector at MOI = 0.5; TGFBR1 and R2 mRNA levels were not significantly changed upon transduction. b. qRT-PCR in primary human myoblasts transduced in vitro with non-target GFP shRNA and Smad3-targeting vectors at MOI = 0.5; unchanged TGFBR1 expression and elevated TGFBR2 expression were detected in three independent experiments with each cohort. c. Analysis of GEO human population gene expression databases [34,35,36,37,38,39,40,41,42,43,44,45,46,47,48] reveals no significant change of TGFBR1 and R2 in people upon viral infections. Scatter plots of different databases showed little variation in the expression in TGFBR1, but increased variation in TGFBR2 after viral infections and increase in Smad3 expression in some studies (while others showed no significant change in Smad3). (Smad3: mean:1.101, SEM:0.004; mean:1.702, SEM:0.011; Mean: 0.979, SEM: 0.012; Mean: 1.611, SEM: 0.115; mean: 1,042, SEM: 0.023); *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001. d. Western blotting analysis of OXTR, pERK1/2, and TGF-β receptor 2 in un-transduced primary mouse myoblasts and mouse myoblasts transduced with non-target shRNA lentiviral vectors. Compared with un-transduced cells, virally transduced myoblasts showed reduction OXTR and pERK1/2 protein levels that became more significant with increased time, while TGF-β receptor 2 levels did not change. Three individual western blots were quantified by pixel intensity. OXTR was normalized to actin, and pERK was normalized to ERK. (*P ≤ 0.05; ** P ≤ 0.01, ***P ≤ 0.001)