Result and Discussion
Identification of differentially expressed genes Protein-protein network construction among DEGs GO enrichment analysis of hub genes
Identification of differentially expressed genes
Totally 37 control samples and 43 SARS – CoV infected samples were considered for analysis.Two different microarray datasets GSE1739 and GSE33267 from GEO were obtained to study the differential in gene expression. Quality Check Analysis was performed of microarray dataset to analyze differential gene expression by using various statistical bioinformatics tool. R programming P-value Log2 Fold change
Volcano plot of differentially expressed genes on analyzing (a) GSE1739 and (b) GSE33267 datasets. Red and blue circles represent up-regulated and downregulated genes respectively. Black circles represent the genes which are not significantly expressed.
Protein –protein network construction among DEGs
For DEGs the protein-protein network was constructed with help of “ Cytoscape ” by using information based on the STRING v11 database . The constructed network demonstrates the protein-protein interaction with pink and yellow colored nodes representing up-regulated and down-regulated genes respectively. The edges in the graph denotes the strength of interaction between the two genes.
BIRC3 IL21R EIF2S3
To understand the association of genes with the various biological processes , genes were functionally analyzed using ShinyGO . Orange, green and blue color bar represents the genes involve in the biological process, cellular component and molecular function
Immune r esponse Ext region system Immune dfector ss region to stress to •crgnign pr ocess H acåvity Cubdy&ate bind Genes
GO enrichment analysis of hub genes
GO enrichment analysis showed the involvement of genes in various functions. Based on the enrichment analysis, DEGs were classified into three categories Genes involved in both cytokine production and neutrophil activation Genes involved in cytokine production alone Genes involved in other immune responses
Overall, on performing differential gene expression analysis, network analysis, gene ontology studies and literature survey, it is clearly evident that ELANE and LTF gene plays significant role in generation of cytokine storm simultaneously resulting death of COVID-19 patients. Hence targeting ELANE and LTF certainly prevents the development of cytokine storms which in turn prevents deaths of patients due to ARDS and organ failure.