Bovine theca and granulosa cell interactions modulate their growth, morphology, and function.

Bovine follicular cells interact in complex ways to regulate ovarian function. Prior research has shown that granulosa and theca cells influence each other's behavior through paracrine signaling. However, the exact nature of their physical and functional interactions remains unclear. No prior work had resolved how coculture affects cell morphology and steroid production. This gap motivated a study to explore how physical contact alters cell behavior. Existing knowledge focused on isolated cell functions, not their interplay. That uncertainty drove the development of a new culture system. No prior work had tested the effects of coculture on progesterone and androstenedione levels. This study aimed to clarify how these interactions shape follicular development.

The goal was to investigate the effects of physical interaction between bovine granulosa and theca cells. Researchers wanted to determine how coculture influences cell morphology, proliferation, and steroidogenesis. They sought to understand whether contact between these cell types alters their behavior. The specific problem addressed was the lack of data on physical cell-cell communication. Motivation came from the need to model natural follicular environments in vitro. The study aimed to test whether coculture leads to changes in cell shape and hormone production. Researchers also wanted to compare cocultured cells with those cultured in isolation. The ultimate aim was to understand how follicular cells coordinate functionally.

The study used a collagen membrane-based culture system. Granulosa and theca cells were placed on opposite sides of the membrane. Researchers observed cell morphology using light microscopy. Proliferation was measured by counting cell numbers after 24 hours. Steroid levels were quantified using enzyme immunoassays. Granulosa cells were cultured alone and in coculture with theca cells. Theca cells were similarly tested in isolation and coculture. The experimental setup allowed for controlled physical but not direct cell-cell contact.

Granulosa cells cultured alone formed flat, polygonal monolayers. Cocultured granulosa cells formed multilayered sheets with convex apical surfaces. Filopodia connected cocultured granulosa cells, indicating physical communication. Theca cells cultured alone were thin and spindle-shaped. Cocultured theca cells retained spindle shape but had convex apical surfaces. Cocultured cells were more densely packed than cells cultured alone. Granulosa cell numbers doubled in coculture compared to controls. Theca cell numbers also doubled in coculture. Progesterone levels from cocultured granulosa cells dropped to 40% of controls. Androstenedione levels from cocultured theca cells tripled compared to controls.

The study shows that physical interaction between granulosa and theca cells alters their morphology and function. Cocultured granulosa cells formed multilayer sheets with filopodia. Theca cells in coculture retained shape but showed convex surfaces. Coculture increased cell proliferation for both cell types. Granulosa cell progesterone production decreased in coculture. Theca cell androstenedione production increased in coculture. These findings suggest that cell-cell communication modulates steroidogenesis. The authors propose that physical contact influences follicular cell function.