MSTRG.118323.5 targets BAG5 as a miR-200-y sponge to regulate Sertoli cells apoptosis via PI3K/AKT/mTOR pathways of...

Bactrian camels show strict seasonal estrus, yet its regulatory mechanisms remain largely unknown. This process involves multi-gene regulation, where ncRNAs (miRNAs, lncRNAs/circRNAs) critically regulate cellular functions. These ncRNAs interact to form competitive endogenous RNA (ceRNA) networks that influence the the cell cycle, proliferation, and apoptosis. In this study, transcriptional sequencing of Bactrian camel testicles identified and validated key seasonal estrus-associated DEGs, lncRNAs, and miRNAs via seq-RNA. Among the identified genes, BAG5, which is associated with testicular development and apoptosis, exhibited significantly higher mRNA and protein levels during anestrus, as determined by qRT-PCR and Western blot. Dual luciferase assays confirmed BAG5 and lncRNA MSTRG.118323.5 as miR-200-y targets. In vitro experiments with miR-200-y mimics and inhibitors confirmed their negative regulation of both BAG5 and lncRNA expression, validated by qPCR (transcripts) and Western blot/immunofluorescence (proteins). Further analysis revealed that BAG5 modulates the PI3K/AKT/mTOR pathway, influencing apoptosis-related proteins. Flow cytometry results indicated that MSTRG.118323.5 binds competitively to miR-200-y, thereby enhancing BAG5' s anti-apoptotic effects. This study reveals a regulatory network involving lncRNA-miRNA-BAG5 in testicular apoptosis and provides novel insights into the molecular mechanisms underlying seasonal estrus and testicular development in Bactrian camels. These findings contribute to a deeper understanding of reproductive regulation in desert-adapted species.