Pituitary adenylate cyclase-activating polypeptide acts synergistically with relaxin in modulating ovarian cell function in rats

Abstract

The interactive effects of pituitary adenylate cyclaseactivating polypeptide (PACAP) and relaxin on the secretion of gelatinases, involved in matrix remodeling, in ovarian theca-interstitial cells and granulosa cells, were investigated in gonadotropin-primed immature rats. The gelatinases secreted from cultured cells were analyzed using gelatin zymography and scanning densitometry. We have previously shown that relaxin stimulated the secretion of a 71 kDa gelatinase, identified as a type IV collagenase (matrix metalloproteinase 2), in rat thecainterstitial cells. This study has demonstrated that PACAP27 and PACAP38, with similar potency, dosedependently enhanced relaxin-induced secretion of 71 kDa gelatinase, whereas PACAP alone had no effect. In rat granulosa cells, both PACAP27 and PACAP38 alone dose-dependently increased the secretion of a 63 kDa gelatinase. In addition, this study has shown that cAMP signaling pathway mediators act similarly to that of PACAP on gelatinase secretion in rat ovarian cells. Cholera toxin, forskolin and 8-bromoadenosine cAMP augmented relaxin-induced secretion of 71 kDa gelatinase in theca-interstitial cells, and alone they had no effect. These mediators also increased the secretion of 63 kDa gelatinase in granulosa cells. It is well known that the increase in cellular cAMP level is associated with the morphological rounding-up phenomenon in granulosa cells. This study has shown that PACAP and cAMP pathway mediators, but not relaxin, could cause such changes in cell shape in granulosa cells as well as in theca-interstitial cells. In conclusion, this study provides original findings that PACAP acts synergistically with relaxin in stimulating the secretion of gelatinases in rat ovarian theca-interstitial cells and granulosa cells. This supports the idea that relaxin and PACAP may serve as ovarian physiological mediators of gonadotropin function in facilitating the ovulatory process. In addition, PACAP appears to act through the cAMP signaling pathway to affect biological functions in ovarian cells, whereas relaxin does not.

Regulation of Human Polymorphonuclear Leukocytes Functions by the Neuropeptide Pituitary Adenylate Cyclase-Activating Polypeptide after Activation of MAPKs

“…PACAP has been reported to act synergistically with relaxin to increase the secretions of MMP-2 in rat thecainterstitial cells (52). Thus, PACAP serves as an ovarian physiological mediator of gonadotropin functions.…”

Potential role of follicle‐stimulating hormone (FSH) and transforming growth factor (TGFβ1) in the regulation of ovarian angiogenesis

“…The presence of gelatinase activity in conditioned media of angiogenic assays was determined using gelatin zymography as previously described (Teng et al, 2000). In brief, medium samples were electrophoresed on 8% SDS‐polyacrylamide gels (14 cm × 10 cm) containing 0.1% gelatin obtained from porcine skin.…”

Critical involvement of ILK in TGFβ1-stimulated invasion/migration of human ovarian cancer cells is associated with urokinase plasminogen activator system

“…Gelatin zymography was performed as previously described [48]. In brief, medium samples were electrophoresed on 7.5% SDS-polyacrylamide gels (14 cm × 10 cm) containing 0.1% gelatin obtained from porcine skin (Sigma).…”