Biochemical insights and microRNA profiling via next-generation sequencing in moderate and severe COVID-19 cases

COVID-19 remains the most devastating and challenging viral disease in human history OBJECTIVE: This study explores the biochemical and host microRNA (miRNA) response to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection and explores how DE miRNAs alter molecular pathways to identify potential prognostic and therapeutic biomarkers.

Biochemical profiling on automated chemistry analyzers and circulating miRNA profiling by Next Generation Sequencing were performed in moderate (ward) and severe (ICU) patients of COVID-19. miRNA Differential Expression (DE) was analyzed in ICU vs. Control and Ward vs. Control Groups. Statistical comparison of biochemical variables amongst ICU, Ward, and Control groups was done on SPSS by applying the Kruskal-Wallis test; p-value < 0.05 was considered significant. miRNA DE analysis was performed with the help of a bioinformatics tool, DESeq2. A False Discovery Rate (FDR) adjusted p-value < 0.05 was considered to be significant.

Most biochemical parameters were significantly and proportionately altered with respect to the severity of the disease. Patients showed compromised renal, hepatic, and cardiac function, as well as deranged blood pictures and elevated inflammatory markers (CRP, IL-6, LDH, and Ferritin). miRNA Differential Expression (DE) when analyzed in both study groups, 102 DE miRNAs were found in the ICU vs. Control group, of which miR-423-5p was significantly upregulated, and miR-744-5p was significantly downregulated. Whereas, in the Ward vs. control group, out of 91 DE miRNAs, only miR-486-5p was observed to be significantly upregulated. Gene targets of these three miRNAs were further explored along with their cellular pathways. Literature suggests that these affected cellular pathways converge on the stimulation of the NF-κB pathway. Biochemical evaluation of COVID-19 cases reveals major disease severity predictors like raised inflammatory markers CRP, IL-6, LDH, elevated organ function tests and deranged hematological profiles.

Three differentially expressed miRNAs were observed that might be involved in the activation of NF-κB, which acts as a major modulator of inflammation in response to SARS-CoV-2 infection. The miRNA findings are preliminary and hypothesis-generating, only requiring independent validation e.g., qPCR in a larger cohort. The probable theragnostic potential of these miRNAs may be clinically explored further by the use of miRNA mimics or miRNA inhibitors that may change the adversity associated with this virus altogether.