mir186 and mir145 In vivo Evaluation and Enrichment in Rats Submitted to Treadmill Strenuous Exercise

Aims: The present study aimed to identify miRNAs differentially expressed in rats submitted to strenuous exercise and in silico investigation of the biological implication of the findings.

Place and Duration of Study: The in vivo experiments and analyses were performed in the Laboratory of Biochemistry and Gene Expression – LABIEX of the Superior Institute of Biomedical Science – ISCB from the State University of Ceará. Between 2017-2020.

Methodology: The study was performed using as subjects 2-month-old male wistar rats, which initially were submitted to 2-week adaptation training. Later the animals were separated in two distinct groups, control (C) and trained (T), where only T performed a single session of strenuous exercise, while C were not submitted to this treatment. The applied exercise protocol consisted in a running training in treadmill with speed constant increasing until the animal exhaustion which was measured by the animal refusal to keep running. After 24h, soleus muscle was desiccated and submitted to RNAseq sequencing protocols. Obtained data were statistically evaluated in R environment with EBSeq package, to characterize and predict the miRNAs and their targets were used bioinformatics tools Gene Cards, mi RBase enrichR and KEGG.

Results: Two differentially expressed miRNAs were found, mir145 and mir 186, both with downregulated expression pattern in strenuous exercise. These miRNAs have a total of 1201 predicted target genes, 67 were repeated and mostly correlate to cardiovascular disease pathways, between those 5 were differentially expressed as down-regulated.

Conclusion: In conclusion, the findings suggest that mir186 and mir145 down-regulation profile mediated by strenuous exercise implicates in the non-alteration of the target genes expression profile, and consequently did not mediate alterations in the pathways they are evolved, which are mainly related to signaling and disorders.