# The mechanisms of energy balance between oxidative phosphorylation and glycolysis in human ovarian granulosa cells

## TL;DR

This study explores how human ovarian granulosa cells balance energy production between mitochondria and glycolysis, finding that inhibiting one pathway leads to compensation by the other.

## Contribution

The study reveals a compensatory mechanism between oxidative phosphorylation and glycolysis in human ovarian granulosa cells to maintain energy balance.

## Key findings

- Inhibiting oxidative phosphorylation or glycolysis significantly reduces ATP levels and mitochondrial membrane potential.
- CCCP treatment upregulates glycolysis-related genes and increases glucose consumption.
- Cell viability improves over time after CCCP treatment, reaching control levels by 72 hours.

## Abstract

This study investigated the interplay between mitochondrial oxidative phosphorylation and glycolysis in human ovarian granulosa cells by analyzing changes induced by the mitochondrial inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and the glycolysis inhibitor bromopyruvic acid (BA).

Mural granulosa cells (mGCs) were isolated from tubal factor infertility patients and cultured. Cells were divided into control, CCCP (10 µM), and BA (0.5 mM) groups. Mitochondrial function was assessed via mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and adenosine triphosphate (ATP) levels. Glycolysis-related gene expression (HIF-1α, GLUT1, LDHA, PFKP) was measured by qRT-PCR after CCCP treatment. Glucose consumption and cell viability (CCK-8 assay) were evaluated in control and CCCP groups at 24, 48, and 72 h.

Compared to controls, both CCCP and BA groups exhibited significantly decreased in MMP (P < 0.0001). and ATP levels (P ≤ 0.001), while ROS showed a non-significant increase (P > 0.05). CCCP treatment significantly upregulated mRNA expression of HIF-1α, GLUT1, LDHA, and PFKP (P < 0.05). Glucose consumption rate significantly increased in the CCCP group at all time points (P < 0.05), peaking at 72 h. Cell viability progressively improved with longer culture duration after-CCCP treatment, showing significant increases at 48 and 72 h (P < 0.05), reaching levels comparable to controls by 72 h (P > 0.05).

Human mGCs utilize both oxidative phosphorylation and glycolysis for energy metabolism. Inhibition of one pathway triggers compensatory upregulation of the other, indicating collaborative regulation between these pathways to maintain cellular function and follicular homeostasis.