Steroidogenesis in luteal cell: A critical pathway for progesterone production

Abstract

Smruti Ranjan Mishra, Tapan Kumar Palai

The ovarian cycle is central to the physiology of reproduction in most domestic mammals; characterized by repeated patterns of cellular proliferation, differentiation and transformation of ovarian steroidogenic cells (granulosa, theca and luteal cells) that accompany follicular development, ovulation, followed by formation, function and regression of the corpus luteum (CL). Luteal cells are the chief cells present in the CL. Steroid hormones are synthesized in the adrenal gland, gonads, and placenta critical for normal reproductive function. Steroidogenesis is the main process that occurs in luteal cells to produce the progesterone that is essential for the establishment and maintenance of pregnancy. Steroidogenic acute regulatory protein, cytochrome P450 side-chain cleavage enzyme, and 3β hydroxylsteroid dehydrogenase enzyme are major regulators of steroidogenesis process in the luteal cells. Progesterone regulates the length of the estrus cycle by influencing the timing of the luteolytic PGF2α signal from the endometrium. Termination of estrus cycle is characterized by functional luteolysis and structural luteolysis. Functional luteolysis is due to regression of CL leading to loss of steroidogenic capacity. Finally, luteal cell death and resorption makes the way to structural luteolysis. Therefore, it is paramount to know the exact mechanism of progesterone production through steroidogenesis process in luteal cells. This review is to highlight the important steps of steroidogenesis process in luteal cells.