Analysis of apoptosis levels and MMP7 gene expression in ovaries of postpartum female rabbits after long-term use of LHRH-A3.

Luteinizing hormone-releasing hormone A3 (LHRH-A3), a reproductive hormone analog, is widely used to stimulate ovulation in female rabbits. However, the long-term impact of sustained LHRH-A3 administration on the reproductive system, particularly ovarian health, remains unclear. In this study, we compared apoptosis levels in ovaries and molecular regulation between LHRH-A3-treated (A3 group) and untreated female rabbits (N group) after their 5th litter. Western blotting showed a significantly lower Bcl-2/Bax ratio in the A3 group compared with the N group (P < 0.01), indicating higher ovarian apoptosis. Ovarian tissues from four rabbits per group were divided into the A3 group and the N group, and RNA-seq technology was then utilized to conduct transcriptome analysis on these two groups. This analysis revealed 220 differentially expressed genes (DEGs), including BMP6, BMP15, CYP1A1, and other reproductive-related genes. KEGG analysis of these DEGs showed their involvement in processes such as the cell cycle, PI3K-Akt signaling pathway, and ovarian steroidogenesis. Subsequently, we selected the key gene Matrix metallopeptidase 7 (MMP7) for functional analysis using CCK8 and Annexin V-FITC/PI techniques. MMP7 was found to promote the proliferation of granulosa cells (GCs) and inhibit apoptosis (P < 0.01). In conclusion, LHRH-A3 treatment can modulate ovarian molecular regulation, with the key gene MMP7 involved in the proliferation and apoptosis of GCs.