Expression of transforming growth factor alpha during development

1988 ◽  
Vol 66 (8) ◽  
pp. 1113-1121 ◽  
Author(s):  
V. K. M. Han ◽  
A. J. D'Ercole ◽  
D. C. Lee
Keyword(s):  
In Situ Hybridization ◽  
Growth Factor ◽  
Mrna Expression ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Alpha ◽  
Egf Receptors ◽  
Hybridization Histochemistry ◽  
In Situ Hybridization Histochemistry ◽  
Factor Alpha

Transforming growth factors (TGFs) are polypeptides that are produced by transformed and tumour cells, and that can confer phenotypic properties associated with transformation on normal cells in culture. One of these growth-regulating molecules, transforming growth factor alpha (TGF-α), is a 50 amino acid polypeptide that is related to epidermal growth factor (EGF) and binds to the EGF receptor. Previous studies have shown that TGF-α is expressed during rodent embryogenesis between 7 and 14 days gestation. To investigate the cellular sites of TGF-α mRNA expression during development, we have performed Northern analyses and in situ hybridization histochemistry on the conceptus and maternal tissues at various gestational ages. Contrary to previous reports, both Northern analyses and in situ hybridization histochemistry indicate that TGF-α mRNA is predominantly expressed in the maternal decidua and not in the embryo. Decidual expression is induced following implantation, peaks at day 8, and declines through day 15 when the decidua is being resorbed. In situ hybridization revealed that expression of TGF-α mRNA is highest in the region of decidua adjacent to the embryo and is low or nondetectable in the uterus, placenta, and embryo. In addition, we could not detect TGF-α mRNA expression in other maternal tissues, indicating that the induction of TGF-α transcripts in the decidua is tissue specific, and not a pleiotropic response to changes in hormonal milieu that occur during pregnancy. The developmentally regulated expression of TGF-α mRNA in the decidua, together with the presence of EGF receptors in this tissue, suggests that this peptide may stimulate mitosis and angiogenesis locally by an autocrine mechanism. Because EGF receptors are also present in the embryo and placenta, TGF-α may act on these tissues by a paracrine or endocrine mechanism.

scholarly journals Human eosinophils express transforming growth factor alpha.

1990 ◽  
Vol 172 (3) ◽  
pp. 673-681 ◽  
Author(s):  
D T Wong ◽  
P F Weller ◽  
S J Galli ◽  
A Elovic ◽  
T H Rand ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Biological Effects ◽  
Hypereosinophilic Syndrome ◽  
Enzyme Analysis ◽  
Transforming Growth Factor Alpha ◽  
Peripheral Tissues ◽  
Factor Alpha

Transforming growth factor alpha (TGF-alpha) is a pleuripotential cytokine with diverse biological effects, including the ability to influence the proliferation of normal cells or neoplastic epithelial cells. Eosinophils are a subset of granulocytes that normally enter the peripheral tissues, particularly those beneath gastrointestinal, respiratory, and urogenital epithelium, where they reside in close proximity to the epithelial elements. In this study, we demonstrate that the great majority of eosinophils infiltrating the interstitial tissues adjacent to two colonic adenocarcinomas and two oral squamous cell carcinomas labeled specifically by in situ hybridization with a 35S-riboprobe for human TGF-alpha (hTGF-alpha). No other identifiable leukocytes in these lesions contained detectable hTGF-alpha mRNA. We also examined leukocytes purified from a patient with the idiopathic hypereosinophilic syndrome. 80% of these eosinophils, but none of the patient's neutrophils or mononuclear cells, were positive for hTGF-alpha mRNA by in situ hybridization, and 55% of these eosinophils were positive by immunohistochemistry with a monoclonal antibody directed against the COOH terminus of the mature hTGF-alpha peptide. Finally, the identification of the purified eosinophil-associated transcript as hTGF-alpha was confirmed by polymerase chain reaction product restriction enzyme analysis followed by Southern blot hybridization. In contrast to eosinophils from the patient with hypereosinophilic syndrome, the peripheral blood eosinophils from only two of seven normal donors had detectable TGF-alpha mRNA and none of these eosinophils contained immunohistochemically detectable TGF-alpha product. Taken together, these findings establish that human eosinophils can express TGF-alpha, but suggest that the expression of TGF-alpha by eosinophils may be under microenvironmental regulation. Demonstration of TGF-alpha production by tissue-infiltrating eosinophils and the eosinophils in the hypereosinophilic syndrome identifies a novel mechanism by which eosinophils might contribute to physiological, immunological, and pathological responses.

Localization of Thyrotropin-Releasing Hormone mRNA Expression in the Rat Heart by in situ Hybridization Histochemistry

Pathobiology ◽  
1996 ◽  
Vol 64 (6) ◽  
pp. 314-319 ◽  
Author(s):  
Zhan-Xiang Shi ◽  
Wen Xu ◽  
Wolfgang J. Mergner ◽  
Qiao-Ling Li ◽  
Katharine H. Cole ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Mrna Expression ◽  
Rat Heart ◽  
Thyrotropin Releasing Hormone ◽  
Hybridization Histochemistry ◽  
Releasing Hormone ◽  
In Situ Hybridization Histochemistry

scholarly journals Epidermal growth factor receptor binding is affected by structural determinants in the toxin domain of transforming growth factor-alpha-Pseudomonas exotoxin fusion proteins.

1989 ◽  
Vol 9 (7) ◽  
pp. 2860-2867 ◽  
Author(s):  
G M Edwards ◽  
D DeFeo-Jones ◽  
J Y Tai ◽  
G A Vuocolo ◽  
D R Patrick ◽  
...  
Keyword(s):  
Growth Factor ◽  
Receptor Binding ◽  
Transforming Growth Factor ◽  
Cell Killing ◽  
Transforming Growth Factor Alpha ◽  
Egf Receptors ◽  
Pseudomonas Exotoxin ◽  
Killing Activity ◽  
Epidermal Growth ◽  
Factor Alpha

TGF-alpha-PE40 is a hybrid protein composed of transforming growth factor-alpha (TGF-alpha) fused to a 40,000-dalton segment of Pseudomonas exotoxin A (PE40). This hybrid protein possesses the receptor-binding activity of TGF-alpha and the cell-killing properties of PE40. These properties enable TGF-alpha-PE40 to bind to and kill tumor cells that possess epidermal growth factor (EGF) receptors. Unexpectedly, TGF-alpha-PE40 binds approximately 100-fold less effectively to EGF receptors than does native TGF-alpha (receptor-binding inhibition IC50 = 540 and 5.5 nM, respectively). To understand the factors governing receptor binding, deletions and site-specific substitutions were introduced into the PE40 domain of TGF-alpha-PE40. Removal of the N-terminal 59 or 130 amino acids from the PE40 domain of TGF-alpha-PE40 improved receptor binding (IC50 = 340 and 180 nM, respectively) but decreased cell-killing activity. Substitution of alanines for cysteines at positions 265 and 287 within the PE40 domain dramatically improved receptor binding (IC50 = 37 nM) but also decreased cell-killing activity. Similar substitutions of alanines for cysteines at positions 372 and 379 within the PE40 domain did not significantly affect receptor-binding or cell-killing activities. These studies indicate that the PE40 domain of TGF-alpha-PE40 interferes with EGF receptor binding. The cysteine residues at positions 265 and 287 of PE40 are responsible for a major part of this interference.

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