Paracrine effects via the epidermal growth factor receptor in the rodent testis may be mediated by non-Leydig interstitial cells

1993 ◽  
Vol 136 (3) ◽  
pp. 439-NP ◽  
Author(s):  
A. Moore ◽  
I. D. Morris
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Leydig Cell ◽  
Leydig Cells ◽  
Interstitial Cell ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Thymidine Incorporation ◽  
Buoyant Density ◽  
Epidermal Growth

ABSTRACT The epidermal growth factor (EGF) receptor is expressed in a wide variety of cell types and is known to be present in the testis of many species including man. In the present study, specific 125 I-labelled EGF binding was observed in isolated interstitial cell preparations from both the intact and Leydig cell-depleted rat testis. It was demonstrated that the population of cells to which 125I-labelled EGF binds has a different buoyant density from either of the two adult Leydig cell populations, and remains unchanged in the absence of Leydig cells following in-vivo treatment with ethane dimethane sulphonate (EDS). Cells of this density (1·064 g/ml) identified by electron microscopy were fusiform mesenchymal cells, identical to those suggested by others to be able to differentiate into Leydig cells in vitro, i.e. Leydig cell precursors. In a culture system using two interstitial cell preparations of different buoyant densities from immature rats, both EGF and transforming growth factor-α (TGF-α) caused increased [3H]thymidine incorporation in the less dense cell preparation. TGF-α was more potent than EGF. EGF increased testosterone production in both fractions in amounts which could be related to the amount of 3β-hydroxysteroid dehydrogenase (3β-HSD)-positive cells. This study demonstrated that rat Leydig cells (defined as those cells which bind 125I-labelled human chorionic gonadotrophin, have distinct buoyant densities, are 3β-HSD positive and are sensitive to EDS), do not bind 125I-labelled EGF. Rather, EGF binds to a mesenchymal cell without LH receptors which is resistant to EDS. Growth factors which act via the EGF receptor increased [3H]thymidine incorporation in a Leydig cell-depleted interstitial fraction which may reflect an action upon the progenitor of the mature Leydig cell. Journal of Endocrinology (1993) 136, 439–446

134. EPIDERMAL GROWTH FACTOR RECEPTOR/MAPK3/1 PATHWAY CROSS-TALK ENABLES GROWTH DIFFERENTIATION FACTOR 9 TO SIGNAL THROUGH SMAD2/3 IN MOUSE GRANULOSA CELLS

2009 ◽  
Vol 21 (9) ◽  
pp. 53
Author(s):  
M. Sasseville ◽  
L. J. Ritter ◽  
T. Nguyen ◽  
D. G. Mottershead ◽  
D. L. Russell ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Granulosa Cells ◽  
Cross Talk ◽  
Egf Receptor ◽  
Thymidine Incorporation ◽  
Differentiation Factor ◽  
Growth Differentiation Factor 9 ◽  
Epidermal Growth ◽  
Receptor Inhibitor

Oocyte-secreted growth differentiation factor 9 (GDF9) plays a critical role throughout folliculogenesis. It has been shown to control many functions of granulosa cells, including gene expression, steroidogenesis and proliferation. This study investigates the cellular requirements that allow GDF9 to act on granulosa cells. Our results showed that GDF9 (20 ng/ml)-stimulated mouse granulosa cells 3H-thymidine incorporation was inhibited by a type 1 receptor Alk4/5/7 inhibitor (SB431542, 5 μM), by an epidermal growth factor (EGF) receptor inhibitor (AG1478, 5μM) and a MEK1 inhibitor (U0126, 10 μM). Interestingly, activin A- and TGFβ-stimulated 3H-thymidine incorporation shared similar inhibitor sensitivity. Moreover, when denuded oocytes were used as the mitogenic agent, SB431542, AG1478 and U0126 all prevented the increase in 3H-thymidine incorporation. Oocyte-stimulated 3H-thymidine incorporation in secondary follicles and cumulus-oocyte complexes were also sensitive to Alk4/5/7, EGF receptor and MEK1 inhibition. Basal and EGF-stimulated levels of phopho-MAPK3/1 were inhibited by using the EGF receptor inhibitor, but were not affected by inhibition of Alk4/5/7 or by adding GDF9 in granulosa cells. Using granulosa cells transfected with a SMAD3-luciferase reporter construct, GDF9-stimulated SMAD3 response could be inhibited by Alk4/5/7, EGFR and MEK1 inhibitors. Genes involved in cumulus cells expansion (Ptx3 and Has2) were upregulated in granulosa cells by co-culturing with denuded oocytes and that upregulation was inhibited by Alk4/5/7 as well as by EGF receptor inhibition. These results suggest that TGFβ superfamily members signalling through Smad2/3 share a common requirement of EGF receptor-dependant phospho-MAPK3/1 throughout folliculogenesis. These results strongly suggest that, apart from its role in the transmission of the ovulatory LH signal within the ovarian follicle, EGF receptor pathway might serve as modulators of GDF9 action on granulosa cells. Hence the interaction between endocrine and oocyte signalling may be mediated at the level of MAPK and Smad2/3 cross-talk in granulosa cells.

scholarly journals Transforming growth factor-alpha (TGF-alpha) in human bone marrow: demonstration of TGF-alpha in erythroblasts and eosinophilic precursor cells and of epidermal growth factor receptors in blastlike cells of myelomonocytic origin

Blood ◽  
1995 ◽  
Vol 85 (9) ◽  
pp. 2385-2392 ◽  
Author(s):  
TM Walz ◽  
C Malm ◽  
BK Nishikawa ◽  
A Wasteson
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Precursor Cells ◽  
Transforming Growth Factor Alpha ◽  
Epidermal Growth ◽  
Factor Alpha

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.

The proliferative responses of porcine thyroid follicular cells to epidermal growth factor and thyrotrophin reflect the autocrine production of transforming growth factor-β1

1996 ◽  
Vol 148 (1) ◽  
pp. 87-94 ◽  
Author(s):  
A J Cowin ◽  
E L Heaton ◽  
S H Cheshire ◽  
S P Bidey
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Transforming Growth Factor ◽  
Thymidine Incorporation ◽  
Transforming Growth Factor Β1 ◽  
Follicular Cells ◽  
Stimulatory Action ◽  
Thyroid Follicular Cells ◽  
Epidermal Growth ◽  
Tgf Β1

Abstract The present study has investigated an involvement of autocrine transforming growth factor-β1 (TGF-β1) in regulating the proliferative response of porcine thyroid follicular cells (TFCs) to epidermal growth factor (EGF) and TSH. Primary monolayer TFC cultures exposed to EGF over the range 0–0·4 nmol/l showed a dose-dependent increase in [methyl-3H]thymidine incorporation, whereas higher EGF doses were associated with a reduction in the level of [methyl-3 H]thymidine incorporation. TGF-β immunoneutralisation had little effect on the stimulatory action of low EGF doses, but led to an increase in [methyl-3H]thymidine incorporation at higher EGF levels. In TFC cultures exposed to TSH, the level of [methyl-3H]thymidine incorporation attained at a dose of 1 U TSH/1 was enhanced in the presence of TGF-β1 antiserum, although the similar stimulatory effect of 8-bromo cAMP was unaffected. Treatment of TFCs with phorbol 12-myristate 13-acetate (8 nmol/l) to activate protein kinase C (PKC) led to an enhanced incorporation of [methyl-3H]thymidine which was increased further after neutralisation of endogenous TGF-β1. While confirming, therefore, a role for autocrine TGF-β1 in maintaining control of TFC DNA synthesis in vitro, these findings provide evidence that an increase in the availability of autocrine TGF-β1 effected by EGF and TSH may play an instrumental role in limiting the cellular hyperplasia induced by these factors within the thyroid follicular microenvironment. Moreover, the present data also suggest that the availability of active autocrine TGF-β1 to TFCs under such conditions may be dependent upon a PKC-mediated mechanism. Journal of Endocrinology (1996) 148, 87–94

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

1988 ◽  
Vol 8 (5) ◽  
pp. 1970-1978 ◽  
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.

Expression of the genes for TGF alpha, EGF and the EGF receptor during early pig development

Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 663-669 ◽  
Author(s):  
T.J. Vaughan ◽  
P.S. James ◽  
J.C. Pascall ◽  
K.D. Brown
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Reverse Transcription Pcr ◽  
Organ Systems ◽  
Maternal Transcripts ◽  
Conceptus Development ◽  
Epidermal Growth

Expression of mRNA for transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF) and the epidermal growth factor receptor (EGF-R) during early pig development was evaluated by reverse transcription-PCR. In the unfertilised pig oocyte, maternal transcripts for EGF, but not for TGF alpha or the EGF-R, were detected. Pig conceptuses were analysed at days 7, 8, 10, 12, 15, 17, 18 and 22 of pregnancy. EGF-R mRNA was detected at all stages of conceptus development analysed. Interestingly, TGF alpha mRNA was expressed by the developing blastocyst only at days 8, 10 and 12 of pregnancy, with the highest levels apparent at day 10. In contrast, EGF mRNA was first expressed by the post-elongation conceptus at around day 15 of pregnancy with levels continuing to increase up to day 22. In the day-18 and day-22 conceptuses, this EGF message was shown to be primarily a product of the embryo-amnion and not the placental membranes. Furthermore, EGF was immunolocalised in the day-22 embryo to the developing lung bud, gut loop and amnion. In summary, the expression pattern of TGF alpha mRNA during early pig development is coincident with the onset of blastocyst elongation and suggests a possible role for TGF alpha during this period of cellular remodelling. The temporal and spatial expression of EGF mRNA and protein suggests a possible involvement for EGF in the establishment of the early organ systems.

Malignant transformation of murine fibroblasts by a human c-Ha-ras-1 oncogene does not require a functional epidermal growth factor receptor

1986 ◽  
Vol 6 (10) ◽  
pp. 3382-3387
Author(s):  
I A McKay ◽  
P Malone ◽  
C J Marshall ◽  
A Hall
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Cellular Transformation ◽  
Egf Receptors ◽  
Ras Gene ◽  
Ras Genes ◽  
Murine Fibroblasts ◽  
Epidermal Growth

Although mutations in ras genes are thought to be important for the development of about 20% of human tumors, almost nothing is known about the way in which these mutations lead to cellular transformation. The known biochemical properties of the 21-kilodalton ras proteins suggest that they may behave as G proteins, regulating the proliferation of cells in response to growth factor stimulation of a receptor. Although the putative receptor(s) has not been identified, several lines of evidence, in particular the fact that rodent cell lines containing ras oncogenes produce transforming growth factor alpha, have suggested that the epidermal growth factor (EGF) receptor is involved in ras transformation. Here we show that murine fibroblasts with no EGF receptors can be transformed to a completely malignant phenotype with a mutated ras gene. It appears, therefore, that the EGF receptor is not required for ras-mediated transformation of these cells.

Sign in / Sign up

Export Citation Format

Share Document