COL1A1 affects apoptosis by regulating oxidative stress and autophagy in bovine cumulus cells

The collagen type I alpha 1 chain (COL1A1), as a major component of extracellular matrix, plays a potential role in the growth and development of bovine follicles. However, its specific role in bovine cumulus cells remains unclear. In this study, we examined apoptosis, the cell cycle and reactive oxygen species after inhibition of COL1A1 expression by siRNA in bovine cumulus cells. Cell proliferation was measured by CCK-8, and mitochondrial membrane potential was detected by fluorescence intensities of JC-1 staining. Moreover, cell autophagy was detected by immunofluorescence, and cell migration was detected by a cell scratch assay. Lactic acid and cholesterol concentration were measured to evaluate the glucose utilization and cholesterol synthesis activity in cumulus cell by optical density detection method. RT-qPCR and Western blot analysis were used to measure changes in key gene expression. The results showed that cumulus cells were found to have an abnormal cell cycle, and the numbers of cells in S phase were significantly reduced, accompanied by decreases in cholesterol synthesis, and cell proliferation ability and an increase in apoptosis rate with siRNA-COL1A1 treatment. These findings were likely due to inhibition of COL1A1 resulting in high levels of ROS in the cells, a decrease in mitochondrial membrane potential, an increase in intracellular autophagy, activation of the apoptotic pathway, and a decrease in lactic acid conversion ability. COL1A1 plays an important role in regulating the physiological and biological functions of bovine cumulus cells.