scholarly journals TGF beta suppresses casein synthesis in mouse mammary explants and may play a role in controlling milk levels during pregnancy.

1993 ◽  
Vol 120 (1) ◽  
pp. 245-251 ◽  
Author(s):  
S D Robinson ◽  
A B Roberts ◽  
C W Daniel

Mammary explants from 14-15-d-pregnant mice synthesize and secrete milk proteins in culture in response to insulin, hydrocortisone, and prolactin. Here we demonstrate that transforming growth factor beta (TGF beta) treatment suppresses, in a dose dependent and reversible manner, the ability of explants to synthesize and secrete milk caseins. TGF beta does not affect the level of casein mRNA within explants but inhibits casein synthesis posttranscriptionally. We also show increased expression of TGF beta 2 and TGF beta 3 in intact mammary gland as pregnancy progresses, with reduced expression of all three TGF betas at the onset of lactation. These findings suggest that endogenously produced TGF beta may limit the accumulation of milk caseins that are produced in the mammary gland during pregnancy.

Development ◽  
1991 ◽  
Vol 113 (3) ◽  
pp. 867-878 ◽  
Author(s):  
S.D. Robinson ◽  
G.B. Silberstein ◽  
A.B. Roberts ◽  
K.C. Flanders ◽  
C.W. Daniel

Transforming Growth Factor-beta 1 (TGF-beta 1) was previously shown to inhibit reversibly the growth of mouse mammary ducts when administered in vivo by miniature slow-release plastic implants. We now report a comparative analysis of three TGF-beta isoforms with respect to gene expression and localization of protein products within the mouse mammary gland. Our studies revealed overlapping expression patterns of TGF-beta 1, TGF-beta 2 and TGF-beta 3 within the epithelium of the actively-growing mammary end buds during branching morphogenesis, as well as within the epithelium of growth-quiescent ducts. However, TGF-beta 3 was the only isoform detected in myoepithelial progenitor cells (cap cells) of the growing end buds and myoepithelial cells of the mature ducts. During pregnancy, TGF-beta 2 and TGF-beta 3 transcripts increased to high levels, in contrast to TGF-beta 1 transcripts which were moderately abundant; TGF-beta 2 was significantly transcribed only during pregnancy. Molecular hybridization in situ revealed overlapping patterns of expression for the three TGF-beta isoforms during alveolar morphogenesis, but showed that, in contrast to the patterns of TGF-beta 1 and TGF-beta 2 expression, TGF-beta 3 is expressed more heavily in ducts than in alveoli during pregnancy. Developing alveolar tissue and its associated ducts displayed striking TGF-beta 3 immunoreactivity which was greatly reduced during lactation. All three isoforms showed dramatically reduced expression in lactating tissue. The biological effects of active, exogenous TGF-beta 2 and TGF-beta 3 were tested with slow-release plastic implants. These isoforms, like TGF-beta 1, inhibited mammary ductal elongation in situ by causing the disappearance of the proliferating stem cell layer (cap cells) and rapid involution of ductal end buds. None of the isoforms were active in inhibiting alveolar morphogenesis. We conclude that under the limited conditions of these tests, the three mammalian isoforms are functionally equivalent. However, striking differences in patterns of gene expression and in the distribution of immunoreactive peptides suggest that TGF-beta isoforms may have distinct roles in mammary growth regulation, morphogenesis and functional differentiation.


1995 ◽  
Vol 108 (3) ◽  
pp. 985-1002 ◽  
Author(s):  
M. Shah ◽  
D.M. Foreman ◽  
M.W. Ferguson

Exogenous addition of neutralising antibody to transforming growth factor-beta 1,2 to cutaneous wounds in adult rodents reduces scarring. Three isoforms of transforming growth factor-beta (1, 2 and 3) have been identified in mammals. We investigated the isoform/isoforms of TGF-beta responsible for cutaneous scarring by: (i) reducing specific endogenous TGF-beta isoforms by exogenous injection of isoform specific neutralising antibodies; and (ii) increasing the level of specific TGF-beta isoforms by exogenous infiltration into the wound margins. Exogenous addition of neutralising antibody to TGF-beta 1 plus neutralising antibody to TGF-beta 2 reduced the monocyte and macrophage profile, neovascularisation, fibronectin, collagen III and collagen I deposition in the early stages of wound healing compared to control wounds. Treatment with neutralising antibodies to TGF-betas 1 and 2 markedly improved the architecture of the neodermis to resemble that of normal dermis and reduced scarring while the control wounds healed with scar formation. Exogenous addition of neutralising antibody to TGF-beta 1 alone also reduced the monocyte and macrophage profile, fibronectin, collagen III and collagen I deposition compared to control wounds. However, treatment with neutralising antibody to TGF-beta 1 alone only marginally reduced scarring. By contrast, wounds treated with neutralising antibody to TGF-beta 2 alone did not differ from control wounds. Interestingly, exogenous addition of the TGF-beta 3 peptide also reduced the monocyte and macrophage profile, fibronectin, collagen I and collagen III deposition in the early stages of wound healing and markedly improved the architecture of the neodermis and reduced scarring. By contrast, wounds treated with either TGF-beta 1 or with TGF-beta 2 had more extracellular matrix deposition in the early stages of wound healing but did not differ from control wounds in the final quality of scarring. This study clearly demonstrates isoform specific differences in the role of TGF-betas in wound healing and cutaneous scarring. TGF-beta 1 and TGF-beta 2 are implicated in cutaneous scarring. This study also suggests a novel therapeutic use of exogenous recombinant, TGF-beta 3 as an anti-scarring agent.


Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2239-2247 ◽  
Author(s):  
SE Jacobsen ◽  
JR Keller ◽  
FW Ruscetti ◽  
P Kondaiah ◽  
AB Roberts ◽  
...  

Transforming growth factor-beta (TGF-beta) has potent antiproliferative effects on human hematopoietic progenitor cells. We report here that TGF-beta 1 and -beta 2 also exert bimodal dose-dependent stimulation of granulocyte-macrophage colony-stimulating factor (CSF) and granulocyte- CSF-induced day 7 granulocyte-macrophage colony-forming units. This increase in colony formation was restricted to low doses (0.01 to 1.0 ng/mL) of TGF-beta 1 and was due to increased granulopoiesis, showing that TGF-beta can affect the differentiation as well as the proliferation of hematopoietic progenitors. Furthermore, TGF-beta 3 was found to be a more potent inhibitor of hematopoietic progenitor cells than TGF-beta 1 and -beta 2. In contrast to the bidirectional proliferative effects of TGF-beta 1 and -beta 2, the effects of TGF- beta 3 on human hematopoiesis were only inhibitory, showing for the first time that TGF-beta isoforms differ not only in potencies but also with regard to the nature of the response they elicit.


Blood ◽  
1990 ◽  
Vol 75 (3) ◽  
pp. 596-602 ◽  
Author(s):  
JR Keller ◽  
IK Mcniece ◽  
KT Sill ◽  
LR Ellingsworth ◽  
PJ Quesenberry ◽  
...  

Abstract We previously reported that transforming growth factor beta (TGF-beta) selectively inhibits colony-stimulating factor-driven hematopoietic progenitor cell growth. We report here that TGF-beta 1 can act directly on hematopoietic progenitors to inhibit the growth of the most primitive progenitors measurable in vitro. Highly enriched populations of hematopoietic progenitor cells were obtained by isolating lineage negative (Lin-), Thy-1-positive (Thy-1+) fresh bone marrow cells, or by isolating cells from interleukin-3 (IL-3) supplemented bone marrow cultures expressing Thy-1 antigen with the fluorescent activated cell sorter. TGF-beta 1 inhibited IL-3-induced Thy-1 expression on Thy-1- negative (Thy-1-) bone marrow cells in a dose-dependent manner with an ED50 of 5 to 10 pmol/L. In addition, TGF-beta 1 inhibited the formation of multipotent and mixed colonies by isolated Thy-1+ cells, while single lineage granulocyte and macrophage colonies were not affected. The growth of Thy-1+ Lin- cells incubated as single cells in Terasaki plates in medium supplemented with IL-3 were inhibited by TGF-beta, demonstrating a direct inhibitory effect. Hematopoietic stem cells, which have a high proliferative potential (HPP) when responding to combinations of growth factors in vitro, have been detected in the bone marrow of normal mice and mice surviving a single injection of 5- fluorouracil. TGF-beta 1 inhibited the growth of all subpopulations of HPP colony forming cells (CFC) in a dose-dependent manner with an ED50 of 5 to 10 pmol/L. Thus, TGF-beta directly inhibits the growth of the most immature hematopoietic cells measurable in vitro.


1989 ◽  
Vol 1 (1) ◽  
pp. 87-97 ◽  
Author(s):  
A B Glick ◽  
K C Flanders ◽  
D Danielpour ◽  
S H Yuspa ◽  
M B Sporn

We have studied the functional interaction between retinoic acid and transforming growth factor-beta (TGF-beta), using the mouse epidermis as a model system. Treatment with retinoic acid increases expression of TGF-beta 2 in cultured keratinocytes in vitro, as well as in the epidermis in vivo. This TGF-beta 2 is secreted in a biologically active form that can bind to surface receptors, in contrast to most other conditions in which TGF-beta is secreted in a latent form. Specific antibodies to TGF-beta 2 partially reverse the ability of retinoic acid to inhibit DNA synthesis in cultured keratinocytes. The regulation of TGF-beta 2 expression by retinoic acid may have important physiological and pharmacological roles in the maintenance of epidermal homeostasis.


Development ◽  
1989 ◽  
Vol 106 (4) ◽  
pp. 759-767 ◽  
Author(s):  
R.W. Pelton ◽  
S. Nomura ◽  
H.L. Moses ◽  
B.L. Hogan

We have studied the temporal and spatial expression of transforming growth factor beta 2 (TGF beta 2) RNA in mouse embryos from 10.5 days post coitum (p.c.) to 3 days post partum (p.p.) by in situ hybridization analysis. TGF beta 2 RNA is expressed in a variety of tissues including bone, cartilage, tendon, gut, blood vessels, skin and fetal placenta, and is in general found in the mesenchymal component of these tissues. The expression of TGF beta 2 RNA changes during development in a manner consistent with a role for the gene product in mediating mesenchymal-epithelial interactions.


1989 ◽  
Vol 9 (12) ◽  
pp. 5508-5515
Author(s):  
C C Bascom ◽  
J R Wolfshohl ◽  
R J Coffey ◽  
L Madisen ◽  
N R Webb ◽  
...  

Regulation of transforming growth factor beta 1 (TGF beta 1), TGF beta 2, and TGF beta 3 mRNAs in murine fibroblasts and keratinocytes by TGF beta 1 and TGF beta 2 was studied. In quiescent AKR-2B fibroblasts, in which TGF beta induces delayed stimulation of DNA synthesis, TGF beta 1 autoregulation of TGF beta 1 expression was observed as early as 1 h, with maximal induction (25-fold) after 6 to 12 h. Increased expression of TGF beta 1 mRNA was accompanied by increased TGF beta protein production into conditioned medium of AKR-2B cells. Neither TGF beta 2 nor TGF beta 3 mRNA, however, was significantly induced, but both were apparently down regulated at later times by TGF beta 1. Protein synthesis was not required for autoinduction of TGF beta 1 mRNA in AKR-2B cells. Nuclear run-on analyses and dactinomycin experiments indicated that autoregulation of TGF beta 1 expression is complex, involving both increased transcription and message stabilization. In contrast to TGF beta 1, TGF beta 2 treatment of quiescent AKR-2B cells increased expression of TGF beta 1, TGF beta 2, and TGF beta 3 mRNAs, but with different kinetics. Autoinduction of TGF beta 2 mRNA occurred rapidly with maximal induction at 1 to 3 h, enhanced TGF beta 3 mRNA levels were observed after 3 h, and increased expression of TGF beta 1 occurred later, with maximal mRNA levels obtained after 12 to 24 h. Nuclear run-on analyses indicated that TGF beta 2 regulation of TGF beta 2 and TGF beta 3 mRNA levels is transcriptional, while TGF beta 2 induction of TGF beta 1 expression most likely involves both transcriptional and posttranscriptional controls. In BALB/MK mouse keratinocytes, minimal autoinduction of TGF beta 1 occurred at only the 12- and 24-h time points and protein synthesis was required for this autoinduction. The results of this study provide an example in which TGF beta 1 and TGF beta 2 elicit different responses and demonstrate that expression of TGF beta 1, and TGF beta 3 are regulated differently. The physiological relevance of TGF beta 1 autoinduction in the context of wound healing is discussed.


1990 ◽  
Vol 38 (12) ◽  
pp. 1831-1840 ◽  
Author(s):  
G A Ksander ◽  
C O Gerhardt ◽  
J R Dasch ◽  
L R Ellingsworth

A polyclonal antibody (CL-B1/29) raised against a synthetic peptide with an amino acid sequence identical to the first 29 N-terminal residues of bovine bone-derived transforming growth factor-beta 2 (TGF-beta 2) was characterized and used for immunolocalization of TGF-beta 2 in adult mice. Reduced staining of immunoblots and tissue after absorption of the antiserum with the immunizing peptide or with TGF-beta 2 but not with purified TGF-beta 1 demonstrated that the reagent is specific for TGF-beta 2, with little or no crossreactivity with TGF-beta 1. The immunolocalization of TGF-beta 2 was investigated in formalin-fixed, paraffin-embedded cultured cells and murine tissue. Specimens pre-digested with testicular hyaluronidase demonstrated immunostaining predominantly of extracellular connective tissue matrix, whereas specimens pre-digested with pronase E demonstrated primarily cytoplasmic staining. Immunoreactivity was widely distributed in connective tissue, muscle, adsorptive and secretory epithelia, especially of endocrine tissue, and neural tissue of adult mice.


1992 ◽  
Vol 117 (3) ◽  
pp. 679-685 ◽  
Author(s):  
A König ◽  
L Bruckner-Tuderman

Collagen VII, the major component of cutaneous anchoring fibrils is expressed at a low level by normal human keratinocytes and fibroblasts in vitro. In cocultures of these two cell types, signals from fibroblasts enhance expression of collagen VII by keratinocytes and vice versa. In this study, the effects of a possible mediator of such a stimulation, transforming growth factor-beta (TGF-beta), were investigated. Its effect on the expression and deposition of the highly insoluble collagen VII was assessed in a semiquantitative manner by a newly developed enzyme-linked immunoassay which is based on immunoblotting. In keratinocyte monocultures, 0.5-20 ng/ml of TGF-beta 2 induced a dose-dependent stimulation of collagen VII expression as measured per microgram of DNA. The maximal enhancement was about sevenfold compared to controls. The effect of TGF-beta 2 was observed already after 12 h, with a steady increase at least up to 3 d. As previous studies have implicated, untreated cocultures of keratinocytes and fibroblasts exhibited a higher basic level of collagen VII expression, which could be further stimulated about twofold by TGF-beta 2. Fibroblasts alone synthesized very minor quantities of collagen VII and could be only weakly stimulated by TGF-beta 2. This growth factor seems a specific enhancer of collagen VII since the expression of laminin, collagen IV, as well as total protein was increased to a much lesser extent. Our data suggest that TGF-beta may be an important mediator of epithelial-mesenchymal interactions and may regulate the synthesis of the anchoring fibrils at the skin basement membrane zone.


Sign in / Sign up

Export Citation Format

Share Document