COL1A1 promotes cell proliferation, cell cycle progression, and anoikis resistance in granulosa cells of chicken pre-ovulatory follicles

Chicken follicular granulosa cells (GCs) are the earliest differentiated follicular somatic cells, which play a crucial role throughout follicular growth and development. The extracellular matrix (ECM) plays a key role in maintaining cell-cell interactions and communication during follicular development. This study investigated the effects of the COL1A1 gene, a major component of ECM, on chicken pre-ovulatory follicular granulosa cells (POGCs) and the related regulatory mechanism. Transcriptomic analysis results showed that silencing COL1A1 significantly inhibited GCs proliferation, cell cycle, and anoikis-related biological functions and pathways. The overexpression of endogenous COL1A1 promoted the GCs proliferation through the ERK1/2 signaling pathway, increased the number of GCs in the S/G2 phase of the cell cycle, and enhanced anoikis resistance of GCs. The exogenous addition of collagen & Iukcy; (Col & Iukcy;) promoted GCs proliferation but did not affect the cell cycle progression and anoikis resistance of GCs. In addition, we identified multiple genes involved in COL1A1 knockdown-induced anoikis in GCs, of which 7 genes including PIK3CA, DAPK2, TSC2, BMF, SRC, NTRK2, and NOTCH1 were identified as the core anoikis genes. Our findings provide new perspectives for exploring the role of ECM in chicken follicle development and lay the foundation for further revealing the regulatory network of follicular development.