The Age-Associated Long Noncoding RNA lnc81 Regulates Ovarian Granulosa Cell Proliferation and Apoptosis Through TEAD2-CCN1/2 Pathway in Mice

Abstract

Ovarian granulosa cells (GCs) are pivotal for follicular homeostasis, and their dysregulated apoptosis drives age-related ovarian aging. The Hippo signaling pathway, modulated by long noncoding RNAs (lncRNAs), is implicated in regulating GCs proliferation and ovarian aging. TEAD2 (Transcriptional Enhanced Associate Domain 2), a key downstream transcription factor of the Hippo signaling pathway, plays a critical role in regulating cell proliferation, apoptosis, and embryonic stem cell self-renewal. However, the precise molecular mechanisms by which lncRNAs influence the Hippo pathway in GCs are not fully understood. Through comprehensive RNA-seq analysis of ovarian tissues across three distinct age groups (3-, 11-, and 17-month-old mice), we identified lnc81 as a senescence-associated lncRNA that physically interacts with TEAD2. RNA immunoprecipitation (RIP) assays demonstrated direct binding between lnc81 and TEAD2, while subcellular fractionation coupled with qRT-PCR revealed predominant nuclear localization of lnc81 in granulosa cells (GCs). Importantly, lnc81 expression exhibited a progressive, age-dependent elevation during ovarian aging. Functional characterization showed that lnc81 knockdown in GCs significantly: (i) Inhibited cellular proliferation (as evidenced by decreased Pcna expression). (ii) Promoted apoptosis (indicated by increased BAX/BCL-2 ratio and elevated TUNEL-positive cells). Mechanistically, while lnc81 depletion upregulated CCN1/CCN2 protein levels, it did not affect TEAD2 expression, suggesting that lnc81 regulates TEAD2 transcriptional activity rather than modulating its protein stability. Our findings highlight lnc81 as a nuclear lncRNA that interacts with TEAD2 to amplify CCN1/CCN2 signaling, thereby promoting GC apoptosis and ovarian aging. This mechanistic insight positions lnc81 as a potential biomarker for age-related ovarian decline and a candidate target for therapeutic intervention.