Effects of Epicatechin on the Expression of MyomiRs-31, -133, -136, -206, -296, and -486 in the Skeletal Muscle of the Offspring of Obese Mothers.

Specific myogenic microRNAs termed "myomiRNAs" are involved in skeletal muscle development and regeneration, and an obesogenic environment in utero may affect these processes. The present study aimed to determine whether this environment induced variations in the expression levels of myomiRs-31, -133, -136, -206, and -296 and whether the administration of (-)-epicatechin (Epi), an exercise mimetic, could modify these variations. Rat Wistar male offspring from control mothers (C) or obese mothers (MO) were treated (C+Epi and MO+Epi) or not treated with Epi (C and MO). MyomiRNA expression in the gastrocnemius and soleus muscles was analyzed via RT‒qPCR, and bioinformatic analysis was used to predict the participation of these miRNAs in different skeletal muscle signal transduction pathways. The expression of myomiRNA-31-5p in the gastrocnemius and soleus was significantly lower in the Epi-treated groups (C+Epi and MO+Epi vs. C and MO). The expression of myomiRNA-206 increased in the gastrocnemius muscles of the MO and MO+Epi groups but decreased in the soleus muscles of the MO and MO+Epi groups. The expression of myomiRNA-296 was increased in the MO group in the gastrocnemius and soleus but was reduced in the Epi stimulus group. The expression of myomiRNA-486 increased in the gastrocnemius of the C+Epi group and decreased in the soleus of the MO+Epi group (p = 0.028 vs. MO). In conclusion, we show that an intrauterine obesogenic environment differentially affects the expression levels of some myomiRNAs and that this effect is modified by epicatechin.