Immunolocalisation of epidermal growth factor (EGF), EGF receptor and transforming growth factor alpha (TGFα) during murine palatogenesis in vivo and in vitro

The expression of transforming growth factor-alpha (TGF-alpha) in human differentiating leukemic cell lines and in circulating human eosinophils prompted the search for an analogous function in normal human bone marrow (BM) cells. Immunohistochemistry, using a monoclonal antibody directed to the mature form of the TGF-alpha molecule, showed TGF-alpha on the erythroblasts of normal donors. This novel property of erythroid cells was found on cells at all stages of maturation, most clearly on nucleated forms but to some extent also on erythrocytes within the BM. The presence of membrane-bound TGF-alpha on erythroblasts was confirmed by immunomagnetic cell sorting with polyclonal TGF-alpha antibodies; the recovered cells consisted almost entirely of erythroblasts. Using another monoclonal antibody directed to TGF-alpha, immunohistochemistry showed a different pattern of positive cells including eosinophilic precursor cells, in accordance with earlier findings in blood eosinophils. In addition, the TGF-alpha immunoreactivity was shown in promyelocytes and neutrophilic myelocytes. The presence of epidermal growth factor (EGF) receptor mRNA in BM cells was demonstrated by reverse transcription polymerase chain reaction, whereas EGF receptor-carrying cells were recognized by immunohistochemistry, using polyclonal antibodies directed to the cytoplasmic part of the EGF receptor. The EGF receptor-positive cell constituted about 3% of the nucleated BM cell population. It was classified as a blastlike cell of myelomonocytic origin by morphologic criteria and CD68 positivity. Our results may indicate a novel function of TGF-alpha in erythrocytic differentiation.

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Chicken epidermal growth factor (EGF) receptor: cDNA cloning, expression in mouse cells, and differential binding of EGF and transforming growth factor alpha.

Molecular and Cellular Biology ◽

10.1128/mcb.8.5.1970 ◽

1988 ◽

Vol 8 (5) ◽

pp. 1970-1978 ◽

Cited By ~ 114

Author(s):

I Lax ◽

A Johnson ◽

R Howk ◽

J Sap ◽

F Bellot ◽

...

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Egf Receptor ◽

Transforming Growth Factor ◽

Transforming Growth Factor Alpha ◽

3T3 Cells ◽

Epidermal Growth ◽

Factor Alpha ◽

Differential Binding ◽

Nih 3T3

The primary structure of the chicken epidermal growth factor (EGF) receptor was deduced from the sequence of a cDNA clone containing the complete coding sequence and shown to be highly homologous to the human EGF receptor. NIH-3T3 cells devoid of endogenous EGF receptor were transfected with the appropriate cDNA constructs and shown to express either chicken or human EGF receptors. Like the human EGF receptor, the chicken EGF receptor is a glycoprotein with an apparent molecular weight of 170,000. Murine EGF bound to the chicken receptor with approximately 100-fold lower affinity than to the human receptor molecule. Surprisingly, human transforming growth factor alpha (TGF-alpha) bound equally well or even better to the chicken EGF receptor than to the human EGF receptor. Moreover, TGF-alpha stimulated DNA synthesis 100-fold better than did EGF in NIH 3T3 cells that expressed the chicken EGF receptor. The differential binding and potency of mammalian EGF and TGF-alpha by the avian EGF receptor contrasts with the similar affinities of the mammalian receptor for the two growth factors.

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Effects of epidermal growth factor and transforming growth factor alpha on the mouse trophoblast outgrowth in vitro

Acta Endocrinologica ◽

10.1530/eje.0.1330741 ◽

1995 ◽

Vol 133 (6) ◽

pp. 741-746 ◽

Cited By ~ 15

Author(s):

Toshifumi Machida ◽

Michiyoshi Taga ◽

Hiroshi Minaguchi

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Epithelial Cells ◽

Conditioned Medium ◽

Transforming Growth Factor ◽

Transforming Growth Factor Alpha ◽

Epidermal Growth ◽

Factor Alpha ◽

Endometrial Epithelial Cells

Machida T, Taga M, Minaguchi H. Effects of epidermal growth factor and transforming growth factor alpha on the mouse trophoblast outgrowth in vitro. Eur J Endocrinol 1995;133:741–6. ISSN 0804–4643 In order to analyze the involvement of growth factors in the implantation mechanism, we examined the direct effects of epidermal growth factor (EGF) and transforming growth factor alpha (TGF-α) on trophoblast outgrowth of the mouse blastocyst in vitro. ICR mouse blastocysts were cultured for 4 days on a culture plate in medium containing EGF or TGF-α or conditioned medium obtained from cultured endometrial epithelial cells. Blastocysts were also co-cultured with endometrial epithelial cells. The trophoblast outgrowth of these cultured blastocysts was observed daily and the percentage of outgrowing embryos was calculated and analyzed statistically by the chi-squared test. Analysis for the specific binding of 125I-EGF in outgrown trophoblasts was carried out by autoradiography. The coculture (days 3 and 4) and the presence of EGF (10 ng/ml, day 4), TGF-α (1 ng/ml, day 3; 10 ng/ml, days 2 and 3; 50 ng/ml, days 2–4) or conditioned medium (days 3 and 4) significantly stimulated the rate of trophoblast outgrowth. Preincubation of the conditioned medium with monoclonal anti-EGF or anti-TGF-α antibody suppressed the stimulatory effect of the conditioned medium on trophoblast outgrowth. The specific 125I-EGF binding in outgrown trophoblasts was demonstrated by autoradiography. These results suggest that EGF and TGF-α play an important role in the implantation process by directly stimulating trophoblast development. Michiyoshi Taga, Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236, Japan

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Regulation of cytokine production in the human thymus: epidermal growth factor and transforming growth factor alpha regulate mRNA levels of interleukin 1 alpha (IL-1 alpha), IL-1 beta, and IL-6 in human thymic epithelial cells at a post-transcriptional level.

Journal of Experimental Medicine ◽

10.1084/jem.174.5.1147 ◽

1991 ◽

Vol 174 (5) ◽

pp. 1147-1157 ◽

Cited By ~ 66

Author(s):

P T Le ◽

S Lazorick ◽

L P Whichard ◽

B F Haynes ◽

K H Singer

Keyword(s):

Growth Factor ◽

Epidermal Growth Factor ◽

Transforming Growth Factor ◽

Interleukin 1 ◽

Thymic Epithelial Cells ◽

Transforming Growth Factor Alpha ◽

Mrna Levels ◽

Epidermal Growth ◽

Factor Alpha

Human thymic epithelial (TE) cells produce interleukin 1 alpha (IL-1 alpha), IL-1 beta, and IL-6, cytokines that are important for thymocyte proliferation. The mRNAs for these cytokines are short-lived and are inducible by multiple stimuli. Thus, the steady-state levels for IL-1 and IL-6 mRNAs are critical in establishing the final cytokine protein levels. In this study we have evaluated the effect of epidermal growth factor (EGF), a growth factor for TE cells, and its homologue transforming growth factor alpha (TGF-alpha), on primary cultures of normal human TE cells for the levels of IL-1 alpha, IL-1 beta, IL-6, and TGF-alpha mRNA. We showed that TE cells expressed EGF receptors (EGF-R) in vitro and in vivo, and that treatment of TE cells with EGF or TGF-alpha increased IL-1 and IL-6 biological activity and mRNA levels for IL-1 alpha, IL-1 beta, and IL-6. Neither EGF nor TGF-alpha increased transcription rates of IL-1 alpha, IL-1 beta, and IL-6 genes, but rather both EGF and TGF-alpha increased cytokine mRNA stability. By indirect immunofluorescence assay, TGF-alpha was localized in medullary TE cells and thymic Hassall's bodies while EGF-R was localized to TE cells throughout the thymus. Thus, TGF-alpha and EGF are critical regulatory molecules for production of TE cell-derived cytokines within the thymus and may function as key modulators of human T cell development in vivo.

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