Proteome Modulation in H9c2 Cardiac Cells by microRNAs miR-378 and miR-378

Abstract

MicroRNAs are a novel class of powerful endogenous regulators of gene expression. MiR-378 and miR-378* are localized in the first intron of the Ppargc1b gene that codes the transcriptional co-activator PGC-1␤. The latter regulates energy expenditure as well as mitochondrial biogenesis. The miR-378:miR-378* hairpin is highly expressed in cardiac cells. To better assess their role in cardiomyocytes, we identified miR-378 and miR-378* targets via a proteomic screen. We established H9c2 cellular models of overexpression of miR-378 and miR-378* and identified a total of 86 down-regulated proteins in the presence of either one of these miRs. Functional annotation clustering showed that miR-378 and miR-378* regulate related pathways in cardiomyocytes, including energy metabolism, notably glycolysis, cytoskeleton, notably actin filaments and muscle contraction. Using bioinformatics algorithms we found that 20 proteins were predicted as direct targets of the miRs. We validated eight of these targets by quantitative RT-PCR and luciferase reporter assay. We found that miR-378 targets lactate dehydrogenase A and impacts on cell proliferation and survival whereas miR-378* targets cytoskeleton proteins actin and vimentin. Proteins involved in endoplasmic reticulum stress response such as chaperone and/or calcium buffering proteins GRP78, PPIA (cyclophilin A), calumenin, and GMMPA involved in glycosylation are repressed by these miRs. Our results show that the miR-378/378* hairpin establishes a connection among energy metabolism, cytoskeleton remodeling, and endoplasmic reticulum function through post-transcriptional regulation of key proteins involved in theses pathways. Molecular & Cellular Proteomics 13: 10.1074/mcp.M113.030569, 18-29, 2014.

The Role of miR-378a in Metabolism, Angiogenesis, and Muscle Biology

“…Increased glycolytic rates and increased cell proliferation can be related to lactate production by lactate dehydrogenase (LDH). LDHA was found to be a direct target of miR-378a in the study of Mallat et al [ 44 ]. In this way, hsa-miR-378a-3p represses cell growth and increases cell death by targeting LDHA.…”

“…Of note, hsa-miR-378a-3p and hsa-miR-378a-5p had opposite effects on LDHA expression. LDHA was significantly downregulated by miR-378a-3p overexpression and upregulated by miR-378a-5p overexpression [ 44 ].…”

MicroRNAs Regulate Mitochondrial Function in Cerebral Ischemia-Reperfusion Injury

“…miR-378 inhibits PGC-1β expression [ 113 ], whereas miR-378-5p activates PGC-1β expression and induces reduction in tricarboxylic acid cycle gene expression [ 114 ] ( Figure 2 ). Numerous miRNAs function during reperfusion which involves in lipid peroxidation and excess lactate production with excessive ROS generation and synthesis of glutathione from glutamate [ 140 ]; the following are the examples: miR-23a/b represses glutaminase expression [ 112 ], miR199-a-5p participates in mitochondrial activity and mitochondrial β-oxidation.…”

Les microARNs : en quoi intéressent-ils les cardiologues ?

“…MiR-378 est un mirtron localisé dans l'intron 1 du gène codant le cofacteur transcriptionnel PGC1b impliqué dans la biogenèse mitochondriale et la b-oxydation des acides gras. Notre équipe a montré que miR-378 et son brin opposé miR-378* répriment des protéines du métabolisme énergétique et du cytosquelette impliqués dans ces processus de remodelage cardiaque [5]. Les miR-199b, miR-132 et miR-212,…”