The COVID-19 disease, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), emerged in late 2019 and rapidly spread worldwide, becoming a pandemic that infected millions of people and caused significant deaths. COVID-19 continues to be a major threat, and there is a need to deepen our understanding of the virus and its mechanisms of infection. To study the cellular responses to SARS-CoV-2 infection, we performed an RNA sequencing of infected vs. uninfected Calu-3 cells. Total RNA was extracted from infected (0.5 MOI) and control Calu-3 cells and converted to cDNA. Sequencing was performed, and the obtained reads were quality-analyzed and pre-processed. Differential expression was assessed with the EdgeR package, and functional enrichment was performed in EnrichR for Gene Ontology, KEGG pathways, and WikiPathways. A total of 1040 differentially expressed genes were found in infected vs. uninfected Calu-3 cells, of which 695 were up-regulated and 345 were down-regulated. Functional enrichment analyses revealed the predominant up-regulation of genes related to innate immune response, response to virus, inflammation, cell proliferation, and apoptosis. These transcriptional changes following SARS-CoV-2 infection may reflect a cellular response to the infection and help to elucidate COVID-19 pathogenesis, in addition to revealing potential biomarkers and drug targets.

Aims: The present study aimed to stablish and characterize an optimized protocol conformation to obtain adequate RNA quality from rodents skeletal muscle samples for sequencing studies. 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 - UECE. Between 2017-2020. Methodology: Were used 23 samples from male Wistar rat skeletal muscle, specifically from soleus muscle. Total RNA extraction was performed using the classic TRIzol® method and commercial kit, merging steps from both. Capillary electrophoresis in the Bioanalyzer platform was used for RNA quality evaluation. Results: (C) Analyzes of adapted protocol RNA concentration, RIN and rate 28S/18S showed satisfactory results. 28S/18S Ribosomal bands appear well defined, without small traces, which indicates RNA with high integrity and without contamination of genomic DNA. Conclusion: Obtained RNA quality and integrity data satisfied the exigencies for posterior RNA-seq.

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.