Biological characteristics of rabbit KLF12 and its regulation of proliferation and apoptosis of ovarian granulosa cells

Granulosa cells (GCs), as the largest somatic cell group in follicles, provide nutrients and microenvironment for oocyte growth and maturation. GC proliferation and apoptosis are influenced by several genes, with the Kruppel Like Factor 12 (KLF12) gene contributing to the modulation of several cellular activities. Nevertheless, the precise modulatory function of this gene within the context of ovarian GCs remains unelucidated. We cloned the KLF12 gene of New Zealand female rabbits, and evaluated its expression and localization in the ovaries of female rabbits of different ages by quantitative real-time PCR (qRT-PCR) and fluorescence in situ hybridization (FISH). In order to determine the role of KLF12 in ovarian GCs, we used qRT-PCR, WB, CCK-8 and Annexin V-FITC/PI to detect the effect of KLF12 on GCs proliferation and apoptosis. The coding sequence of KLF12 gene of New Zealand female rabbit was predicted and cloned for the first time in this study. The coding region was 1209 bp, encoding 402 amino acids. KLF12 overexpression has a negative effect on the proliferation and cell cycle progression of rabbit GCs. KLF12 knockdown partially rescues GCs proliferation, accelerates GCs cycle progression, and promotes Estradiol (E2) and Progesterone (P) secretion. In addition, KLF12 was also proved to be a key regulator of PI3K/Akt signaling pathway in GCs. In conclusion, the study provides evidence that KLF12 plays a pivotal role in the maturation and proliferation of ovarian GCs in female rabbits. This work establishes a conceptual foundation for investigating deeper into the possible regulatory mechanisms underlying follicular development and growth. Author summaryGCs are essential for oocyte growth, not only providing necessary nutritional support for oocyte growth and maturation, but also constructing a key microenvironment. In this study, the biological function of KLF12 gene was systematically elucidated in rabbit for the first time. It was found that KLF12 inhibited follicular development by negatively regulating GCs proliferation and cell cycle. Combined with its effect on E2 and P secretion, the important regulatory role of KLF12 in follicular maturation and hormone balance was revealed. These innovative findings not only deepen the understanding of the regulatory network of ovarian development, but also provide a new theoretical basis for the basic research of reproductive biology. More importantly, it provides a potential molecular target for the development of new technologies to improve the reproductive efficiency of livestock. It also provides a valuable reference model for the study of the mechanism of human reproductive dysfunction related diseases.