Li Wenxin, Lu Minjun, Shang Junyu, Zhou Jiamin, Lin Li, Liu Yueqin, Zhao Dan, Zhu Xiaolan
Reproductive Medicine Center, The Fourth Affiliated Hospital of Jiangsu University, No. 20 Zhengdong Road, Zhenjiang, Jiangsu Province, 212001, China.
Department of Central Laboratory, The Fourth Affiliated Hospital of Jiangsu University, Zhenjiang, China.
Stem Cell Res Ther. 2024 Dec 18;15(1):484. doi: 10.1186/s13287-024-04098-0.
Premature ovarian insufficiency (POI) is an ovarian dysfunction disorder that significantly impacts female fertility. Ovarian granulosa cells (GCs) are crucial somatic components supporting oocyte development that rely on glycolysis for energy production, which is essential for follicular growth. Hypoxia-induced exosomal circRNAs regulate glycolysis, but their biological functions and molecular mechanisms in POI are largely unexplored. The present comprehensive investigation revealed a substantial reduction in ovarian glycolysis levels in POI rats. Notably, hypoxia-induced exosomes originating from mesenchymal stem cells (HM-Exs) exhibit a remarkable capacity to enhance ovarian glycolysis, mitigate GCs apoptosis, reinstate disrupted estrous cycles, modulate sex hormone levels, and curtail the presence of atretic follicles. These restorative actions collectively contribute to fostering fertility revival in POI-afflicted rats.
Cyclophosphamide was administered for 2 weeks to induce POI rat model, and POI rats were randomly divided into three groups and treated with PBS, NM-Exs and HM-Exs, respectively. Ovarian function and fertility were assessed at the end of the study and ovarian tissues were collected for analysis of energy metabolites. The relationship between circDennd2a and POI was explored in vitro by qRT-PCR, Western blotting, CCK-8 assay, EdU staining, TUNEL staining, extracellular acidification rate (ECAR) measurements, and ATP, lactate and pyruvate level assays.
Our findings revealed depletion of circDennd2a in serum samples and GCs from individuals suffering from POI. The introduction of HM-Exs-derived circDennd2a (HM-Exs-circDennd2a) effectively counteracted GCs apoptosis by enhancing glycolytic processes and driving cellular proliferation. CircDennd2a interacted with lactate dehydrogenase A (LDHA), which served as a catalyst to increase LDHA enzymatic activity and facilitate the conversion of NADH to NAD+. This biochemical cascade worked synergistically to sustain glycolytic function within GCs.
This study revealed that HM-Exs-circDennd2a promoted LDHA activity and enhanced GCs glycolytic capacity, both of which support its use as a potential clinical diagnostic and therapeutic target for POI.
卵巢早衰（POI）是一种严重影响女性生育能力的卵巢功能障碍性疾病。卵巢颗粒细胞（GCs）是支持卵母细胞发育的关键体细胞成分，其能量产生依赖糖酵解，而这对卵泡生长至关重要。缺氧诱导的外泌体环状RNA调控糖酵解，但其在POI中的生物学功能和分子机制在很大程度上尚未得到探索。目前的综合研究表明，POI大鼠的卵巢糖酵解水平显著降低。值得注意的是，源自间充质干细胞的缺氧诱导外泌体（HM-Exs）具有显著增强卵巢糖酵解、减轻GCs凋亡、恢复紊乱的发情周期、调节性激素水平以及减少闭锁卵泡存在的能力。这些恢复作用共同有助于促进POI患病大鼠的生育能力恢复。
给予环磷酰胺2周以诱导POI大鼠模型，将POI大鼠随机分为三组，分别用PBS、正常间充质干细胞来源的外泌体（NM-Exs）和HM-Exs进行处理。在研究结束时评估卵巢功能和生育能力，并收集卵巢组织用于分析能量代谢物。通过qRT-PCR、蛋白质免疫印迹法、CCK-8检测、EdU染色、TUNEL染色、细胞外酸化率（ECAR）测量以及ATP、乳酸和丙酮酸水平检测，在体外探索环状Dennd2a（circDennd2a）与POI之间的关系。
我们的研究结果显示，POI患者血清样本和GCs中的circDennd2a缺失。引入源自HM-Exs的circDennd2a（HM-Exs-circDennd2a）通过增强糖酵解过程和促进细胞增殖有效地对抗了GCs凋亡。CircDennd2a与乳酸脱氢酶A（LDHA）相互作用，LDHA作为催化剂增加LDHA酶活性并促进NADH向NAD + 的转化。这一生物化学级联协同作用以维持GCs内的糖酵解功能。
本研究表明，HM-Exs-circDennd2a促进LDHA活性并增强GCs糖酵解能力，这两者均支持其作为POI潜在的临床诊断和治疗靶点。
