The direct actions of @entity60015 / @entity60015 (KL) in developing ovarian follicles were investigated. Previous studies have shown that granulosa cells express KL that can support oocyte development. The current study demonstrates that KL can also act directly on theca cells to promote cellular growth and differentiation. Through RT-PCR analysis it was shown that @entity291 granulosa cells express KL, and theca cells express the receptor @entity58385 . @entity291 theca interna cells were isolated and cultured in serum-free conditions to study KL actions. KL stimulated theca cell growth in a dose-dependent manner as measured by @entity665 incorporation into DNA when cells were cultured under subconfluent conditions. KL had no effect on theca cell @entity2671 or @entity1420 production under these growth-permissive conditions. In contrast, KL stimulated theca cell @entity2671 production but had no effect on @entity1420 production when theca cells were cultured under confluent (non-growth-permissive) conditions. @entity53 (10(-7) M) and @entity1 CG (100 ng/ml) were used as controls and regulated theca cell @entity134 production at any cell density. These results demonstrate that KL can directly stimulate theca cell growth and @entity134 production during follicular development. The observation that KL stimulated @entity2671 production but not @entity1420 production suggests that KL promotes a follicular phase differentiated state in theca cells. The potential regulation of KL and @entity58385 expression during follicular development was studied using a specific quantitative RT-PCR procedure. Total RNA from granulosa cells (for KL) and theca cells (for @entity58385 ) was examined from small (<5 mm), medium (5-10 mm), and large (>10 mm) size follicles. Steady state levels of KL messenger RNA were highest in granulosa cells from large size follicles and lowest in small and medium size follicles. No differences were observed in the steady state levels of @entity58385 messenger RNA in theca cells from small, medium, or large size follicles. The observation that KL expression is highest in large size follicles suggests that KL may be important for increased growth and @entity134 production in large and dominant follicles. Observations demonstrate that KL can dramatically alter theca cell function and support the hypothesis that local granulosa-theca cell interactions play an important role in regulating cellular function within ovarian follicles. This study identifies KL as the first granulosa cell-derived growth factor that can directly stimulate theca cell growth and @entity2671 production in the absence of gonadotropins.

Direct actions of XXXX on theca cell growth and differentiation during follicle development.

@entity1 :: ('9606', 'Species') :: ['human'] @entity60015 :: ('281885(Tax:9913)', 'Gene') :: ['kit-ligand', 'stem cell factor'] @entity1420 :: ('MESH:D011374', 'Chemical') :: ['progesterone'] @entity58385 :: ('280832(Tax:9913)', 'Gene') :: ['c-kit'] @entity2671 :: ('MESH:D000735', 'Chemical') :: ['androstenedione'] @entity665 :: ('CHEBI:53526', 'Chemical') :: ['[3H]thymidine'] @entity53 :: ('MESH:D004958', 'Chemical') :: ['Estradiol'] @entity134 :: ('CHEBI:35341', 'Chemical') :: ['steroid'] @entity291 :: ('9913', 'Species') :: ['bovine', 'Bovine']
@entity60015 :: (281885(Tax:9913),Gene) :: ['kit-ligand']
