Downregulation of Glucose-Energy Metabolism via AMPK Signaling Pathway in Granulosa Cells of Diminished Ovarian Reserve Patients
Glucose metabolism plays a crucial role in the function of granulosa cells (GCs) and the development of follicles. In cases of diminished ovarian reserve (DOR), alterations in these processes can impact female fertility. This study aims to investigate changes in glucose-energy metabolism in GCs of young DOR patients aged 20 to 35 years and their correlation with the onset and progression of DOR. 72 DOR cases and 75 women with normal ovarian reserve (NOR) as controls were included based on the POSEIDON and Bologna criteria. Samples of GCs and follicular fluid (FF) were collected for a comprehensive analysis involving transcriptomics, metabolomics, RT-qPCR, JC-1 staining, and flow cytometry. The study identified differentially expressed genes and metabolites in GCs of DOR and NOR groups, revealing 7 common pathways related to glucose-energy metabolism, along with 11 downregulated genes and 14 metabolites. Key substances in the glucose-energy metabolism pathway, such as succinate, lactate, NADP, ATP, and ADP, showed decreased levels, with the DOR group exhibiting a reduced ADP/ATP ratio. Downregulation of genes involved in glycolysis (HK, PGK, LDH1), the TCA cycle (CS), and gluconeogenesis (PCK) was observed, along with reduced glucose content and expression of glucose transporter genes (GLUT1 and GLUT3) in DOR GCs. Additionally, decreased AMPK pathway activity and impaired mitochondrial function in DOR suggest a connection between mitochondrial dysfunction and disrupted energy metabolism. Above all, the decline in glucose-energy metabolism in DOR is closely associated with its onset and progression. Reduced glucose uptake and impaired mitochondrial function in DOR GCs lead to internal energy imbalances, hindering the AMPK signaling pathway, limiting energy production and supply, and ultimately impacting follicle development and maturation. Overall design: This study aimed to investigate the alterations in glucose-energy metabolism in granulosa cells (GCs) of patients with diminished ovarian reserve (DOR).Initially, transcriptome analysis was conducted on three GCs from each group to assess gene expression differences. Following this, non-targeted metabolomic and targeted metabolite analyses were performed on three GCs from each group. ATP levels were measured using six GCs from each group, while mitochondrial membrane potential was assessed using the JC-1 assay on ten GCs from each group. AMPK and GLUT1 protein levels were analyzed in four GCs from each group, and glucose content was measured in nine GCs from each group. Additionally, follicular fluid analysis was conducted on five samples from each group to evaluate sugars and sugar alcohols. All experiments were approved by the ethics committee of the First Hospital of Lanzhou University (LDYYLL2019-44).