Division of Pediatric and Adolescent Gynecology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA.
BioTuring Inc, San Diego, California, USA.
Clin Transl Med. 2024 Oct;14(10):e70043. doi: 10.1002/ctm2.70043.
Classic galactosemia (CG) is an inborn error of galactose metabolism caused by mutations in the GALT gene. Premature ovarian insufficiency (POI) is a later complication that affects 80% of women with CG due to a significant decline in ovarian reserve (primordial follicle pool). The definite mechanisms underlying the early onset of POI in CG patients are not fully understood.
In this study, we performed single-nucleus RNA sequencing (snRNA-seq) and spatial transcriptomics on ovary tissue biopsies from prepubertal girls diagnosed with CG to investigate dynamic changes in gene expression and altered signalling pathways in granulosa cells, oocytes, and stromal cells.
We generated single-nucleus and spatial transcriptomics atlas of human ovaries from prepubertal girls diagnosed with and without CG. snRNA-seq profiling of the paediatric ovary revealed a diverse ovarian microenvironment with seven distinct major cell types. Our transcriptomic analysis revealed an increase in the expression of several endoplasmic reticulum stress and oxidative stress associated genes, which can promote apoptosis of granulosa cells in CG. PTEN/PI3K/AKT signalling, which is crucial for primordial follicle activation and survival was dysregulated as supported by upregulated PTEN transcripts and a significant reduction in phospho-AKT levels in the granulosa cells and oocytes. We also found a marked increase in expression of phospho-H2A.X, LC3A/B and CASP9 in the primordial follicles of CG ovaries suggesting DNA damage, autophagy, and accelerated follicular atresia. Furthermore, we noticed genes participating in extracellular matrix organisation, integrin and gap junction signalling, essential for structural support of the ovarian stroma were profoundly altered.
Our findings provide molecular insights into the dysregulated cellular signalling pathways essential for primordial follicle growth and survival that can explain the etiology of POI in CG patients. This study has implications in the development of future therapeutic interventions to preserve ovarian function and promote female reproductive health.
Created a comprehensive single-nucleus transcriptomic atlas and spatial landscape of paediatric ovary tissue from prepubertal girls diagnosed with classic galactosemia (CG). Our transcriptomic analysis revealed activation of genes associated with ER-stress signalling, oxidative stress response and ATM signalling/DNA damage response as shown by significant increase in expression of p-EIF2A, p-H2A.X and LC3A/B in the primordial follicles of CG ovary. PTEN/PI3K/AKT signalling pathways was dysregulated evidenced by a significant reduction in phospho-AKT expression in the primordial follicles of CG ovary, suggesting impaired follicle activation and survival.
经典型半乳糖血症（CG）是一种由 GALT 基因突变引起的先天性半乳糖代谢错误。卵巢储备功能衰竭（POI）是一种后期并发症，由于卵巢储备（原始卵泡池）显著下降，80%的 CG 女性都会发生这种情况。CG 患者 POI 早期发病的确切机制尚不完全清楚。
本研究对诊断为 CG 的青春期前女孩的卵巢组织活检进行了单细胞 RNA 测序（snRNA-seq）和空间转录组学分析，以研究颗粒细胞、卵母细胞和基质细胞中基因表达的动态变化和信号通路的改变。
我们生成了来自青春期前患有和不患有 CG 女孩的人类卵巢的单细胞和空间转录组图谱。儿科卵巢的 snRNA-seq 分析显示，卵巢具有多种不同的微环境，其中有七种主要的细胞类型。我们的转录组分析显示，几种内质网应激和氧化应激相关基因的表达增加，这可能会促进 CG 中颗粒细胞的凋亡。PTEN/PI3K/AKT 信号通路对于原始卵泡的激活和存活至关重要，正如我们所支持的那样，颗粒细胞和卵母细胞中的 PTEN 转录本上调，磷酸化 AKT 水平显著降低。我们还发现 CG 卵巢原始卵泡中磷酸化 H2A.X、LC3A/B 和 CASP9 的表达显著增加，表明 DNA 损伤、自噬和加速卵泡闭锁。此外，我们注意到参与细胞外基质组织、整合素和间隙连接信号的基因发生了深刻改变，这些基因对卵巢基质的结构支持至关重要。
我们的研究结果提供了对原始卵泡生长和存活所必需的细胞信号通路失调的分子见解，可以解释 CG 患者 POI 的病因。这项研究对开发未来的治疗干预措施以保留卵巢功能和促进女性生殖健康具有重要意义。
创建了一个全面的青春期前 CG 女孩卵巢组织的单细胞转录组图谱和空间图谱。我们的转录组分析显示，与内质网应激信号、氧化应激反应和 ATM 信号/DNA 损伤反应相关的基因被激活，这表现为 CG 卵巢原始卵泡中 p-EIF2A、p-H2A.X 和 LC3A/B 的表达显著增加。PTEN/PI3K/AKT 信号通路失调，表现为 CG 卵巢原始卵泡中磷酸化 AKT 表达显著降低，提示卵泡激活和存活受损。
