Follicular Stage-Dependent Tumor Necrosis Factor α-Induced Hen Granulosa Cell Integrin Production and Survival in the Presence of Transforming Growth Factor α In Vitro1

Abstract

The link between cell adhesion to extracellular matrix and integrin-mediated survival signals has been established in several physiological systems, and roles for the cytokines tumor necrosis factor alpha (TNF alpha) and transforming growth factor alpha (TGF alpha) have been suggested. TGF alpha stimulates fibronectin production in hen granulosa cells and is an important survival factor during follicular maturation. In contrast, the role of TNF alpha and its possible interaction with TGF alpha in the regulation of granulosa cell fate (death versus survival) during ovarian follicular development have not been fully elucidated. The object of the current study was to determine if TNF alpha and TGF alpha interact in the regulation of hen granulosa cell fibronectin and integrin content in the context of cell death and survival during follicular development. TGF alpha (0.1 or 10 ng/ml), but not TNF alpha (0.1 or 10 ng/ml), increased both cellular and secreted fibronectin content in granulosa cell cultures of F5,6 but not F1 follicles. The expression of integrin beta(3) subunit was also stimulated by TGF alpha in a follicular stage-dependent manner, and culture of F5,6 granulosa cells with TNF alpha in the presence of maximal stimulatory concentrations of TGF alpha potentiated this response. TGF alpha increased both F5,6 and F1 granulosa cell [(3)H]thymidine incorporation but not 3-(4,5-dimethylthiazol-2-yl)3,5-diphenyl tetrazolium bromide (MTT) metabolism. Although TNF alpha had no effect on [(3)H]thymidine incorporation irrespective of the presence of the growth factor, MTT metabolism was higher in F5,6 granulosa cells cultured for 24 h with both TNF alpha and TGF alpha than with either cytokine alone. Incubation of F5,6 granulosa cells for 48 and 72 h resulted in a TGF alpha-inhibited loss of cellular adhesion and detachment of granulosa cells from the growth surface. Although TNF alpha alone had no effect on cell morphology, it facilitated the reorganization of the granulosa cells into multicellular follicle-like structures in the presence of the growth factor. DNA degradation significantly increased between 0 and 72 h of culture in the absence of the cytokine but was suppressed by the addition of TGF alpha but not of TNF alpha. However, fluorometric analysis indicated that the primary type of cell death exhibited by F5,6 granulosa cells during extended culture and attenuated by the presence of TNF alpha and TGF alpha was necrosis and not apoptosis. The current study demonstrates that TNF alpha and TGF alpha interact in the regulation of granulosa cell integrin content and cell survival in vitro in a follicular stage-dependent manner. These findings suggest that follicular development is accompanied by a change in the intraovarian role of TNF alpha; it is atretogenic prior to follicular selection but prevents follicular demise during preovulatory growth.

E1B and E4 oncoproteins of adenovirus antagonize the effect of apoptosis inducing factor

“…Apoptotic nuclear bodies are typically composed of cellular DNA and nuclear material pulling away from a central mass. The resulting fragments of nuclear material are not defined by a distinct boundary of nuclear lamina as we report here (Soboloff et al, 2001; Zhao et al, 2006). Indeed, breakdown of the nuclear lamina precedes nuclear fragmentation during apoptosis (Burke, 2001; Lazebnik et al, 1995).…”

Changes in the population of lymphocytes expressing CD4 and CD8 during the process of atresia of white follicles in hens

“…2000). Cell death signals in the atretic follicles of the hen have also been reported (Bridgham & Johnson 2001; Soboloff et al . 2001).…”

TNF-α Suppressed FSH-Induced LH Receptor Expression Through Transcriptional Regulation in Rat Granulosa Cells

“…During follicle selection in the ovary, with the exception of 1 dominant follicle, follicular growth is arrested. Although the exact mechanisms of this process are not yet known, it has been shown that the atretic process begins with apoptotic cell death in the granulosa, and local TNF-␣ is suspected to be involved in the apoptosis of GCs in atretic follicles (46). In earlier follicle stages, it has been suggested that TNF-␣ protects immature follicles from the effect of gonadotropins by means of inhibitory effects on the expression of gonadotropin receptors.…”