Integrative Analyses of Genes and miRNAs Associated With Age-Related Sarcopenia
Abstract Background: Sarcopenia is an age-related disease with skeletal muscle loss, weakness, and functional impairment. The potential causes of sarcopenia including the programmed cell death of muscles, inflammation, reactive oxygen species, protein turnover, and mitochondrial dysfunction have been studied. The purpose of this study was to find differentially expressed miRNAs (DE-miRNAs) in the muscle samples of older people (GSE23527). In addition, we performed to identify new miRNA-mRNA regulatory network for treating sarcopeniaMethods: Gene expression profiles were obtained from microarray datasets (GSE8479 and GSE1428) of the vastus lateralis muscles of young and older male subjects. Dataset GSE23527 was derived from the platform of GPL10358 (LC_MRA-1001_miRHuman_11.0_080411) and contained microRNA arrays of 12 young muscle samples and 12 older muscle samples. The DEGs between the older and young GSE8479 and GSE1428 samples were identified using the online analysis tool imaGEO (https://imageo.genyo.es). Pathway and process enrichment analysis with the ontology sources in the KEGG pathway, GO biological processes, Reactome gene sets, WikiPathways, and CORUM were analyzed by Metascape. A PPI (protein-protein interaction) network of DEGs was constructed using the Search Tool for Retrieval of Interacting Genes (STRING) app in Cytoscape software (version 1.6.0). GEO2R (https://www.ncbi.nlm.nih.gov) was used to select differentially expressed miRNAs (DE-miRNAs) in the GSE 23527 dataset.Results: In the GSE8479 and GSE1428 datasets, a total of 81 DEGs were discovered, including four upregulated genes and 77 downregulated genes. The top 12 clusters and their representative enriched terms were identified using Metascape. A total of 79 nodes and 186 edges were predicted in the PPI network. One upregulated DE-miRNA (hsa-miR-450a-5p) and six downregulated DE-miRNAs (hsa-miR-127-3p, hsa-miR-24-2-5p, hsa-miR-378a-5p, hsa-miR-532-5p, hsa-miR-487b-5p, and has-miR-487b-3p) were selected in the miRBase database. The MiRWalk online database was utilized for exploring 8017 genes that were selected as genes regulated by DE-miRNAs and six of them overlapped with hub genes. COX7A1 and NDUFB5 showed significantly low expression in sarcopenia patients compared to the controls. COX7B and PDHA1 also displayed low expression in sarcopenia patients, but expression of COX7A1 and NDUFB5 was not significant. TIMM8A and CS showed similar expression rates in both samples.Conclusions: The present bioinformatics analysis showed that two target genes (COX7A1 and NDUFB5) were potentially downregulated in sarcopenia patients. These two genes could be the cause of sarcopenia with aging. In addition, present study showed that several miRNAs (hsa-miR-378a-5p, hsa-miR-532-5p, hsa-miR-127-3p, and hsa-miR-24-2-5p) were identified as regulating the target genes. These results suggest that controlling the identified miRNAs could be a prospective strategy for treating sarcopenia by regulating the mRNA-miRNA network.