TY - JOUR
T1 - Opposing actions of TGFβ and MAP kinase signaling in undifferentiated hen granulosa cells
AU - Woods, Dori C.
AU - Haugen, Morgan J.
AU - Johnson, A. L.
N1 - Funding Information:
We thank J.T. Bridgham, J.P. Witty, and C. Ratajczak for their contributions to the early stages of these studies. This work was supported by NSF Grants IBN01-31185 and IOB04-45949 to A.L.J.
PY - 2005/10/21
Y1 - 2005/10/21
N2 - The present studies were conducted to establish interactions between transforming growth factor (TGF)-β and the epidermal growth factor (EGF) family members, TGFα and betacellulin (BTC), relative to proliferation and differentiation of granulosa cells in hen ovarian follicles. Results presented demonstrate expression of TGFβ isoforms, plus TGFα, BTC, and ErbB receptors in prehierarchal follicles, thus establishing the potential for autocrine/paracrine signaling and cross-talk within granulosa cells at the onset of differentiation. Treatment with TGFα or BTC increases levels of TGFβ1 mRNA in undifferentiated granulosa cells, while the selective inhibitor of mitogen activated protein kinase signaling, U0126, reverses these effects. Moreover, TGFβ1 attenuates c-myc mRNA expression and granulosa cell proliferation, while TGFα blocks both these inhibitory effects. Collectively, these data provide evidence that EGF family ligands regulate both the expression and biological actions of TGFβ1 in hen granulosa cells, and indicate that the timely interaction of these opposing factors is an important modulator of both granulosa cell proliferation and differentiation.
AB - The present studies were conducted to establish interactions between transforming growth factor (TGF)-β and the epidermal growth factor (EGF) family members, TGFα and betacellulin (BTC), relative to proliferation and differentiation of granulosa cells in hen ovarian follicles. Results presented demonstrate expression of TGFβ isoforms, plus TGFα, BTC, and ErbB receptors in prehierarchal follicles, thus establishing the potential for autocrine/paracrine signaling and cross-talk within granulosa cells at the onset of differentiation. Treatment with TGFα or BTC increases levels of TGFβ1 mRNA in undifferentiated granulosa cells, while the selective inhibitor of mitogen activated protein kinase signaling, U0126, reverses these effects. Moreover, TGFβ1 attenuates c-myc mRNA expression and granulosa cell proliferation, while TGFα blocks both these inhibitory effects. Collectively, these data provide evidence that EGF family ligands regulate both the expression and biological actions of TGFβ1 in hen granulosa cells, and indicate that the timely interaction of these opposing factors is an important modulator of both granulosa cell proliferation and differentiation.
UR - http://www.scopus.com/inward/record.url?scp=24644499588&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=24644499588&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2005.08.107
DO - 10.1016/j.bbrc.2005.08.107
M3 - Article
C2 - 16139244
AN - SCOPUS:24644499588
SN - 0006-291X
VL - 336
SP - 450
EP - 457
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -