Transcriptional Profiling of SARS-CoV-2-Infected Calu-3 Cells Reveals Immune-Related Signaling Pathways

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.

Transcriptional profile in rat muscle: down-regulation networks in acute strenuous exercise

Background

Physical exercise is a health promotion factor regulating gene expression and causing changes in phenotype, varying according to exercise type and intensity. Acute strenuous exercise in sedentary individuals appears to induce different transcriptional networks in response to stress caused by exercise. The objective of this research was to investigate the transcriptional profile of strenuous experimental exercise.

Methodology

RNA-Seq was performed with Rattus norvegicus soleus muscle, submitted to strenuous physical exercise on a treadmill with an initial velocity of 0.5 km/h and increments of 0.2 km/h at every 3 min until animal exhaustion. Twenty four hours post-physical exercise, RNA-seq protocols were performed with coverage of 30 million reads per sample, 100 pb read length, paired-end, with a list of counts totaling 12816 genes.

Results

Eighty differentially expressed genes (61 down-regulated and 19 up-regulated) were obtained. Reactome and KEGG database searches revealed the most significant pathways, for down-regulated gene set, were: PI3K-Akt signaling pathway, RAF-MAP kinase, P2Y receptors and Signaling by Erbb2. Results suggest PI3K-AKT pathway inactivation by Hbegf, Fgf1 and Fgr3 receptor regulation, leading to inhibition of cell proliferation and increased apoptosis. Cell signaling transcription networks were found in transcriptome. Results suggest some metabolic pathways which indicate the conditioning situation of strenuous exercise induced genes encoding apoptotic and autophagy factors, indicating cellular stress.

Conclusion

Down-regulated networks showed cell transduction and signaling pathways, with possible inhibition of cellular proliferation and cell degeneration. These findings reveal transitory and dynamic process in cell signaling transcription networks in skeletal muscle after acute strenuous exercise.

Physiological targets for the treatment of diabetic encephalopathy

BACKGROUND

Diabetes mellitus is a chronic degenerative disease responsible for hyperglycemic episodes through insulin secretion deficiency or cellular resistance. Clinical diagnosis in diabetic patients established that this disease affects the CNS, damaging the brain and impairing cognition, and thus establishing a clinical diabetic condition named diabetic encephalopathy. Despite the physiological mechanisms responsible for the development diabetic encephalopathy are still unclear, an excessive formation of reactive oxygen species, an alteration of acetylcholinesterase activity, and a reduction of growth factor levels, may be related with the pathogenesis of this condition. Pharmacological treatments with natural compounds have been proven useful to treat and cure a wide variety of diseases through their antioxidant actions.

METHODS

This study built a compendium of chemical compounds used for the treatment of diabetic encephalopathy demonstrating the most important physiological targets that future drugs should aim for, reviewing them.

RESULTS

As previously suspected, antioxidants and acetylcholinesterase inhibitors were useful to prevent memory loss in streptozotocin-induced animals. In addition, growth factors showed an improvement of memory in diabetic rodents. Most studies focused on antioxidant compounds despite cross studies researched both antioxidants and acetylcholinesterase activities.

CONCLUSION

Therefore, it could be suggested that future studies regarding treatments for diabetic encephalopathy should focus on the antioxidant profile and acetylcholinesterase, since they seem to play pivotal roles in cognitive impairment in diabetes. No less important, studies with growth factors are also important physiological targets for treating the diabetic encephalopathy.