scholarly journals Intracellular pH regulation in hep G2 cells: Effects of epidermal growth factor, transforming growth factor-α, and insulinlike growth factor-II on Na+/H+ exchange activity

Hepatology ◽  
1995 ◽  
Vol 22 (2) ◽  
pp. 588-597
Author(s):  
Mario Strazzabosco ◽  
Carlo Poci ◽  
Carlo Spirlì ◽  
Akos Zsembery ◽  
Anna Granato ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Ph Regulation ◽  
Hep G2 ◽  
Hep G2 Cells ◽  
Transforming Growth Factor Α ◽  
Factor Ii ◽  
Epidermal Growth ◽  
Factor Α ◽  
Exchange Activity

Insulin-like growth factor-II and transforming growth factor-α in developing human fetal pancreatic islets

1993 ◽  
Vol 138 (1) ◽  
pp. 127-NP ◽  
Author(s):  
P. J. Miettinen ◽  
T. Otonkoski ◽  
R. Voutilainen
Keyword(s):  
Growth Factor ◽  
Cyclic Amp ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Α ◽  
Factor Ii ◽  
Epidermal Growth ◽  
Insulin Mrna ◽  
Igf Receptor ◽  
Factor Α

ABSTRACT To understand the development of the human pancreas better, we studied the expression and regulation of insulin, insulin-like growth factor-II (IGF-II) and transforming growth factor-α (TGF-α) genes in the human fetal pancreas and islet-like cell clusters (ICC) from the second trimester human fetuses. Northern blot analysis revealed an abundant expression of IGF-II, insulin and TGF-α mRNAs in the intact pancreas and the cultured ICCs. Furthermore, transcripts for insulin receptor, type-1 and -2 IGF receptors, and GH receptor could be amplified by polymerase chain reaction analysis from the pancreas and the ICCs. With in-situ hybridization, IGF-II mRNA was found in abundance in both the exocrine and endocrine pancreas, exceeding the amount of insulin mRNA. In ICCs, insulin mRNA-containing cells were present as small clusters in the periphery and in the centre of the clusters corresponding to the immunolocation of insulin. The ICCs also contained many epidermal growth factor-, insulin- and type-1 IGF receptor- and TGF-α-positive cells. When the ICCs were cultured in the presence of various secretagogues, only dibutyryl cyclic AMP was found to up-regulate insulin mRNA (39%; P < 0·05). IGF-II mRNA was also under cyclic AMP-dependent regulation (threefold increase; P = 0·025). Furthermore, blocking the type-1 IGF receptor with a monoclonal receptor antibody drastically reduced insulin expression (87%; P = 0·005) and additionally down-regulated IGF-II mRNA (49%; P = 0·005). IGF-1, IGF-II, TGF-α or epidermal growth factor-receptor antibody had no significant effect on either insulin or IGF-II mRNA. Exogenous TGF-α inhibited the release of insulin by the ICCs. It was concluded that IGF-II and TGF-α may be involved in the regulation of islet growth and differentiation. Journal of Endocrinology (1993) 138, 127–136

Inappropriate expression of human transforming growth factor (TGF)-α in the uterus of transgenic mouse causes downregulation of TGF-β receptors and delays the blastocyst-attachment reaction

1997 ◽  
Vol 18 (3) ◽  
pp. 243-257 ◽  
Author(s):  
S K Das ◽  
H Lim ◽  
J Wang ◽  
B C Paria ◽  
M BazDresch ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Receptor Subtypes ◽  
Transforming Growth Factor Α ◽  
Decidual Cells ◽  
Proliferation And Differentiation ◽  
Epidermal Growth ◽  
Β Receptor ◽  
Factor Α ◽  
Inappropriate Expression

ABSTRACT In the mouse, the initiation of the attachment reaction between the blastocyst trophectoderm and luminal epithelium of the receptive uterus occurs in the evening (2200-2300 h) of day 4 of pregnancy (day 1=vaginal plug) and is followed by proliferation and differentiation of stromal cells into decidual cells at the sites of blastocyst attachment. This investigation demonstrates that an inappropriate expression of the human transforming growth factor α (hTGF-α) transgene in the uterus under the direction of a mouse metallothionein-I promoter downregulates uterine expression of TGF-β receptor subtypes and delays the initiation of implantation (attachment reaction) resulting in delayed parturition. This delay in the attachment reaction is accompanied by deferred uterine expression of amphiregulin. The results suggest that a coordinated 'cross-talk' between the signaling pathways executed by epidermal growth factor-like growth factors and TGF-βs is important for the normal implantation process.

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