Long Non-Coding RNA lncXIRP1 Regulates the Proliferation and Apoptosis of Pig Leydig Cells

Leydig cells (LCs) originate from stem Leydig cells (SLCs) and synthesize testosterone, a hormone indispensable for the development, sustenance, and functionality of the male reproductive system. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) play pivotal roles in animal reproductive processes, yet the functional contributions of lncRNAs in pig LCs remain largely uncharacterized. The aim of this study was to examine how lncRNAs influence the function of LCs and their underlying molecular regulatory mechanisms. To achieve this, RNA-seq was conducted on cells before ethane dimethane sulfonate (EDS) treatment (SLCs and LCs) and after EDS treatment (SLCs), identifying 887 significantly downregulated lncRNAs and 30 upregulated lncRNAs after EDS treatment. Bioinformatics analysis identified lncXIRP1 for further investigation. The effects of lncXIRP1 on LCs proliferation, apoptosis, and expression of genes related to testosterone synthesis were investigated by using RT-qPCR, Western blot, CCK-8 and other methods. Bioinformatics predictions have unveiled the existence of a binding site between lncXIRP1 and IGFBP3. Through RT-qPCR experiments and a dual-luciferase reporter system, it was conclusively demonstrated that lncXIRP1 has the capacity to repress the expression of IGFBP3 mRNA, thereby inhibiting the proliferation and transcription activity of genes associated with testosterone synthesis in LCs and promoting their apoptosis. These results provide a theoretical foundation for further exploration of the impact of lncRNAs on LCs function and improving pig reproductive performance.