m6A Regulator-Mediated RNA Methylation Modification Patterns Regulate the Immune Microenvironment in Osteoarthritis

Abstract

Epigenetic regulation, particularly RNA n6 methyl adenosine (m6A) modification, plays an important role in the immune response. However, the regulatory role of m6A in the immune microenvironment in osteoarthritis (OA) remains unclear. Accordingly, we systematically studied RNA modification patterns mediated by 23 m6A regulators in 38 samples and discussed the characteristics of the immune microenvironment modified by m6A. Next, we constructed a novel OA m6A nomogram, an m6A-transcription factor-miRNA network, and a drug network. Healthy and OA samples showed distinct m6A regulatory factor expression patterns. <i>YTHDF3</i> expression was upregulated in OA samples and positively correlated with type II helper cells and <i>TGFb</i> family member receptors. Furthermore, three different RNA modification patterns were mediated by 23 m6A regulatory factors; in Mode 3, the expression levels of <i>YTHDF3</i>, type II T helper cells, and <i>TGFb</i> family member receptors were upregulated. Pathways related to endoplasmic reticulum oxidative stress and mitochondrial autophagy showed a strong correlation with the regulatory factors associated with Mode 3 and 23 m6A regulatory factors. Through RT-qPCR we validated that <i>SREBF2</i> and <i>EGR1</i> as transcription factors of <i>YTHDF3</i> and <i>IGF2BP3</i> are closely associated with the development of OA, hsa-miR-340 as a miRNA for <i>YTHDF3</i> and <i>IGF2BP3</i> was involved in the development of OA, we also detected the protein expression levels of <i>IGF2BP3</i>, <i>YTHDF3</i>, <i>EGR1</i> and <i>SREBF2</i> by western blotting, and the results were consistent with PCR. Overall, the constructed nomogram can facilitate the prediction of OA risk.