Ovarian Interstitial Cells (OIC)

Primary ovarian interstitial cells are a major, yet historically understudied, cell population within the ovarian stroma. They are classified into two main types based on their origin: primary interstitial cells, which differentiate from fibroblast-like stromal cells during ovarian development and have no direct anatomical relation to growing follicles, and secondary interstitial cells, which originate from the theca interna of atretic follicles.

These cells are now recognized as key players in ovarian physiology. They are steroidogenic, possessing the ultrastructural features of classic steroid-producing tissues. Functionally, they are crucial for synthesizing androgens, which serve as precursors for estrogen production in neighboring granulosa cells. Beyond hormone production, ovarian interstitial cells provide structural support and contribute to the ovarian microenvironment through paracrine signaling. Recent research highlights their role in supporting follicle growth and estradiol production. Furthermore, their dysfunction is increasingly linked to reproductive disorders such as polycystic ovary syndrome (PCOS). The identification of progenitor populations within the ovarian stroma marks a significant advance in understanding ovarian biology and its potential for regeneration.