Guo Juncen, Hu Yuanyuan, Cao Qi, Zhang Ying, Jia Yihe, Liu Lan, Zeng Yanru, Wu Xiao, Song Yuelin, Yang Maosen, Xu Wenming, Hu Yang, Huang Wei, Tang Tian
Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China.
Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, China.
J Cell Mol Med. 2025 Sep;29(17):e70820. doi: 10.1111/jcmm.70820.
Diminished ovarian reserve (DOR) poses significant challenges in reproductive health, with emerging evidence implicating DNA damage repair pathways. While GADD45A is a critical regulator of DNA repair, cell cycle and apoptosis, its role in DOR pathogenesis remains unexplored. We employed transcriptome sequencing, qPCR and Western Blot analyses to compare GADD45A expression in granulosa cells (GCs) between DOR patients and controls. Functional studies included GADD45A overexpression/knockdown in human granulosa cells (KGN line) and phenotypic characterisation of Gadd45a knockout (KO) mice. Ovarian reserve parameters (follicle counts, hormone levels, oestrus cyclicity) and in vitro fertilisation outcomes were systematically evaluated. DOR patients exhibited significant upregulation of GADD45A in GCs, concomitant with reduced FSHR and CYP19A1 expression. In vitro experiments revealed that GADD45A overexpression disrupted both proliferation (Cell cycle analysis and EdU staining) and differentiation (Reduced CYP19A1 and FSHR expression) in GCs, while knockdown specifically impaired differentiation (Elevated CYP19A1 and FSHR expression). Gadd45a KO mice displayed hallmark DOR features: irregular oestrus cycles (Shorter oestrus), ovarian volume reduction, ovarian hormones dysregulation and decreased ovarian reserve (reduced primordial follicles and antral follicles, and increased atretic follicles). We found GADD45A was robustly expressed in the ovarian stroma and GCs of atretic follicles. KO oocytes showed compromised developmental competence with decreased two-cell embryo rate in vitro fertilisation. Our findings establish GADD45A dysregulation as a mechanistic contributor to DOR through dual impacts on granulosa cell differentiation and follicle survival. The Gadd45a KO mouse recapitulates key clinical DOR phenotypes, providing a validated model for therapeutic discovery.
卵巢储备功能减退（DOR）给生殖健康带来了重大挑战，新出现的证据表明DNA损伤修复途径与之相关。虽然GADD45A是DNA修复、细胞周期和细胞凋亡的关键调节因子，但其在DOR发病机制中的作用仍未得到探索。我们采用转录组测序、qPCR和蛋白质免疫印迹分析，比较DOR患者和对照组颗粒细胞（GCs）中GADD45A的表达。功能研究包括在人颗粒细胞（KGN系）中过表达/敲低GADD45A以及对Gadd45a基因敲除（KO）小鼠进行表型特征分析。系统评估了卵巢储备参数（卵泡计数、激素水平、发情周期）和体外受精结果。DOR患者的GCs中GADD45A显著上调，同时FSHR和CYP19A1表达降低。体外实验表明，GADD45A过表达破坏了GCs的增殖（细胞周期分析和EdU染色）和分化（CYP19A1和FSHR表达降低），而敲低则特异性损害分化（CYP19A1和FSHR表达升高）。Gadd45a KO小鼠表现出典型的DOR特征：发情周期不规律（发情期缩短）、卵巢体积减小、卵巢激素失调以及卵巢储备功能下降（原始卵泡和窦卵泡减少，闭锁卵泡增加）。我们发现GADD45A在卵巢基质和闭锁卵泡的GCs中大量表达。KO卵母细胞在体外受精时显示出发育能力受损，二细胞胚胎率降低。我们的研究结果表明，GADD45A失调通过对颗粒细胞分化和卵泡存活的双重影响，成为DOR的一个机制性因素。Gadd45a KO小鼠概括了关键的临床DOR表型，为治疗发现提供了一个经过验证的模型。
