MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons

Bhupender Sharma; Melissa M Torres; Sheryl Rodriguez; Laxman Gangwani; Subodh Kumar

doi:10.4103/NRR.NRR-D-23-01064

MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons

Neural Regen Res. 2024 Dec 1;19(12):2698-2707. doi: 10.4103/NRR.NRR-D-23-01064. Epub 2024 Mar 1.

Authors

Bhupender Sharma¹, Melissa M Torres¹, Sheryl Rodriguez¹, Laxman Gangwani², Subodh Kumar^{1

3}

Affiliations

¹ Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA.
² Bond Life Sciences Center and Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA.
³ L. Frederick Francis Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX, USA.

PMID: 38595288
DOI: 10.4103/NRR.NRR-D-23-01064

Abstract

JOURNAL/nrgr/04.03/01300535-202412000-00026/figure1/v/2024-04-08T165401Z/r/image-tiff Gamma-aminobutyric acid (GABA)ergic neurons, the most abundant inhibitory neurons in the human brain, have been found to be reduced in many neurological disorders, including Alzheimer's disease and Alzheimer's disease-related dementia. Our previous study identified the upregulation of microRNA-502-3p (miR-502-3p) and downregulation of GABA type A receptor subunit α-1 in Alzheimer's disease synapses. This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function. In vitro studies were performed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs. In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunit α-1 mRNA. Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunit α-1 gene and suppresses the luciferase activity. Furthermore, quantitative reverse transcription-polymerase chain reaction, miRNA in situ hybridization, immunoblotting, and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunit α-1 level, while suppression of miR-502-3p increased the level of GABA type A receptor subunit α-1 protein. Notably, as a result of the overexpression of miR-502-3p, cell viability was found to be reduced, and the population of necrotic cells was found to be increased. The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney (HEK) recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function, suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function. Additionally, the levels of proteins associated with Alzheimer's disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression. The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p. We propose that micro-RNA, in particular miR-502-3p, could be a potential therapeutic target to modulate GABAergic synapse function in neurological disorders, including Alzheimer's disease and Alzheimer's disease-related dementia.