Linc00513 sponges miR-7 to modulate TGF-β signaling in azoospermia

Abstract

Azoospermia, or the complete absence of sperm in the ejaculate, affects about 1% of men worldwide and is a significant fertility challenge. This study investigates Linc00513, a long non-coding RNA, and its potential role in regulating the TGF-β signaling pathway, a key player in spermatogenesis, in the context of azoospermia. We show that Linc00513 expression is significantly lower in testicular tissues from azoospermic patients than in HS1 controls. Linc00513 interacts directly with microRNA-7 (miR-7) via complementary base pairing, acting as a competing endogenous RNA (ceRNA). This interaction effectively inhibits miR-7's inhibitory action on the TGF-β receptor 1 (TGFBR1), a critical component of the TGF-β signaling cascade. Downregulating Linc00513 reduces TGFBR1 repression and increases TGF-β signaling in azoospermic testes. Functional assays with spermatogonial cell lines support these findings. Silencing Linc00513 leads to increased cell proliferation and decreased apoptosis, similar to TGF-β inhibition. Overexpression of miR-7 inhibits the effects of Linc00513 on TGF-β signaling. Our study sheds new light on how Linc00513, miR-7, and the TGF-β signaling pathway interact in azoospermia. Linc00513 regulates TGFBR1 expression and thus influences spermatogonial cell fate by acting as a miR-7 ceRNA. These findings identify a potential therapeutic target for azoospermia treatment, paving the way for future research into restoring fertility in affected individuals.