# Combined Transcriptome and Metabolome Analyses of Oxidative Stress Regulatory Mechanism in Porcine Follicular Granulosa Cells

## TL;DR

This study explores how oxidative stress causes death in pig egg-supporting cells and identifies key molecules that may help protect these cells.

## Contribution

The study integrates transcriptomic and metabolomic data to reveal novel regulatory mechanisms and key metabolites involved in oxidative stress in porcine granulosa cells.

## Key findings

- 328 genes showed significant activity changes, many related to cell death pathways like TNF and p53.
- 150 altered metabolites were identified, mainly linked to energy production and amino acid metabolism.
- Taurine, creatine, serine, and hypoxanthine were highlighted as key regulators of oxidative stress response.

## Abstract

This study investigates how oxidative stress leads to the death of granulosa cells, which are essential for egg development in pigs. Such cell death is a key factor causing follicular degeneration and reduced fertility. The researchers exposed these cells to hydrogen peroxide, a common source of cellular stress, and analyzed the resulting changes in gene activity and small molecule production. They found 328 genes whose activity changed significantly, many linked to processes that control cell death. In addition, 150 chemical compounds within the cells were altered, mainly those involved in energy production and amino acid metabolism. Further analysis identified several important molecules—taurine, creatine, serine, and hypoxanthine—that appear to help regulate the cell’s response to oxidative stress. The findings suggest that these molecules and related biological pathways may play protective roles in maintaining cell health. Overall, this study provides new insights into how oxidative stress affects reproductive cells and could guide strategies to improve animal fertility and potentially human reproductive health by reducing stress-related cell damage.

Follicular atresia is mainly driven by the oxidative stress-induced apoptosis of granulosa cells (GCs). Oxidative stress mediated by H2O2 is the predominant form of stress in cells and plays a key role in the death of porcine GCs. In the present study, using integrated transcriptomic and untargeted metabolomic approaches, we explored the mechanisms underlying the regulation of oxidative stress in porcine follicular GCs. Per the transcriptomic analysis, compared with the control group, we identified 328 differentially expressed mRNAs (260 upregulated, 68 downregulated) in the H2O2-treatment group; these mRNAs were significantly enriched in apoptosis-related pathways, including the tumour necrosis factor (TNF) and p53 signalling pathways. Furthermore, via untargeted metabolomic analysis, we identified 150 differentially expressed metabolites (101 positive, 49 negative). The pathways associated with protein digestion and absorption, glycine, serine, and threonine metabolism, amino acid biosynthesis, and carbon metabolism were enriched with these metabolites. The integrated transcriptomic and metabolomic analyses revealed taurine, creatine, L-serine, and hypoxanthine as the key metabolites under H2O2-induced oxidative stress. Both the differential genes and metabolites were notably enriched in the FOXO and mineral absorption pathways. In the present study, we elucidated the regulatory mechanism underlying H2O2-induced oxidative stress in porcine follicular GCs via transcriptomic and metabolomic analyses. Our findings offer novel insights into the alleviation of oxidative stress in GCs.