Bovine ovarian follicular growth and development correlate with lysophosphatidic acid expression

•Expression of the CD36, BTC, TFG, DBI, PGES and RABGAP1 is follicle type-depended in granulosa and theca cells.•LPARs, AX, PLA2 correlate with factors involved in follicular growth in healthy and transitional but not in atretic follicles.•The highest number of correlations was distinctive for theca in comparison to granulosa cells.•The highest number of correlations was typical for healthy follicles in comparison to transitional follicles.•We suggest role of LPA in follicular development with its impact on TFG, DBI and RABGAP1 in granulosa and TFG in theca cells.•We postulate the role of LPA in the growth, development and physiology of the bovine ovarian follicle.

The basis of successful reproduction is proper ovarian follicular growth and development. In addition to prostaglandins and vascular endothelial growth factor, a number of novel factors are suggested as important regulators of follicular growth and development: PGES, TFG, CD36, RABGAP1, DBI and BTC. This study focuses on examining the expression of these factors in granulosa and thecal cells that originate from different ovarian follicle types and their link with the expression of lysophosphatidic acid (LPA), known local regulator of reproductive functions in the cow.Ovarian follicles were divided into healthy, transitional, and atretic categories. The mRNA expression levels for PGES, TFG, CD36, RABGAP1, DBI and BTC in granulosa and thecal cells in different follicle types were measured by real-time PCR. The correlations among expression of enzymes synthesizing LPA (autotaxin, phospholipase A2), receptors for LPA and examined factors were measured. Immunolocalization of PGES, TFG, CD36, RABGAP1, DBI and BTC was examined by immunohistochemistry.We investigated follicle-type dependent mRNA expression of factors potentially involved in ovarian follicular growth and development, both in granulosa and thecal cells of bovine ovarian follicles. Strong correlations among receptors for LPA, enzymes synthesizing LPA, and the examined factors in healthy and transitional follicles were observed, with its strongest interconnection with TFG, DBI and RABGAP1 in granulosa cells, and TFG in thecal cells; whereas no correlations in atretic follicles were detected. A greater number of correlations were found in thecal cells than in granulosa cells as well as in healthy follicles than in transitional follicles. These data indicate the role of LPA in the growth, development and physiology of the bovine ovarian follicle.