scholarly journals Transcriptional regulation of the transforming growth factor beta 1 promoter by v-src gene products is mediated through the AP-1 complex.

1990 ◽  
Vol 10 (9) ◽  
pp. 4978-4983 ◽  
Author(s):  
M C Birchenall-Roberts ◽  
F W Ruscetti ◽  
J Kasper ◽  
H D Lee ◽  
R Friedman ◽  
...  

Growth factor-independent 32D-src and 32D-abl cell lines, established by infecting the interleukin-3-dependent myeloid precursor cell line (32D-123) with retroviruses containing the src or abl oncogene, were used to study transcriptional regulation of transforming growth factor beta 1 (TGF-beta 1) mRNA. Analysis of different TGF-beta 1 promoter constructs regulated by pp60v-src indicated that sequences responsive to high levels of src induction contain binding sites for AP-1. Both src and serum induced expression of the c-fos and c-jun genes in myeloid cells, resulting in transcriptional activation of the TGF-beta 1 gene. We found that serum treatment increased TGF-beta 1 mRNA levels in 32D-123 cells and that the v-Src protein could replace the serum requirement by stimulating binding to the AP-1 complex of the TGF-beta 1 promoter, thereby mediating the induction of TGF-beta 1 transcription.

1990 ◽  
Vol 10 (9) ◽  
pp. 4978-4983
Author(s):  
M C Birchenall-Roberts ◽  
F W Ruscetti ◽  
J Kasper ◽  
H D Lee ◽  
R Friedman ◽  
...  

Growth factor-independent 32D-src and 32D-abl cell lines, established by infecting the interleukin-3-dependent myeloid precursor cell line (32D-123) with retroviruses containing the src or abl oncogene, were used to study transcriptional regulation of transforming growth factor beta 1 (TGF-beta 1) mRNA. Analysis of different TGF-beta 1 promoter constructs regulated by pp60v-src indicated that sequences responsive to high levels of src induction contain binding sites for AP-1. Both src and serum induced expression of the c-fos and c-jun genes in myeloid cells, resulting in transcriptional activation of the TGF-beta 1 gene. We found that serum treatment increased TGF-beta 1 mRNA levels in 32D-123 cells and that the v-Src protein could replace the serum requirement by stimulating binding to the AP-1 complex of the TGF-beta 1 promoter, thereby mediating the induction of TGF-beta 1 transcription.


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.


1993 ◽  
Vol 13 (6) ◽  
pp. 3588-3597
Author(s):  
L Scotto ◽  
R K Assoian

Chimeric plasmids containing selected reporter coding domains and portions of the transforming growth factor beta 1 (TGF-beta 1) 3' untranslated region (UTR) were prepared and used to identify potential mechanisms involved in regulating the biosynthesis of TGF-beta 1. Transient transfections with core and chimeric constructs containing the chloramphenicol acetyltransferase (CAT) reporter showed that steady-state CAT mRNA levels were decreased two- to threefold in response to the TGF-beta 1 3' UTR. Interestingly, CAT activity was somewhat increased in the same transfectants. Thus, production of CAT protein per unit of mRNA was stimulated by the TGF-beta 1 3' UTR (approximately fourfold in three cell lines of distinct lineage). The translation-stimulatory effect of the TGF-beta 1 3' UTR suggested by these studies in vivo was confirmed in vitro by cell-free translation of core and chimeric transcripts containing the growth hormone coding domain. These studies showed that production of growth hormone was stimulated threefold by the TGF-beta 1 3' UTR. A deletion analysis in vivo indicated that the GC-rich domain in the TGF-beta 1 3' UTR was responsible for both the decrease in mRNA levels and stimulation of CAT activity-mRNA. We conclude that this GC-rich domain can have a bifunctional effect on overall protein expression. Moreover, the notable absence of this GC-rich domain in TGF-beta 2, TGF-beta 3, TGF-beta 4, and TGF-beta 5 indicates that expression of distinct TGF-beta family members can be differentially controlled in cells.


1991 ◽  
Vol 11 (7) ◽  
pp. 3795-3803
Author(s):  
R Lafyatis ◽  
R Lechleider ◽  
A B Roberts ◽  
M B Sporn

Transforming growth factor-beta 3 (TGF-beta 3) mRNA is differentially expressed in developing and mature mouse tissues, including high-level expression in developing and adult cardiac tissue. We show now that TGF-beta 3 mRNA is also expressed highly in skeletal muscle as well as in the mouse skeletal myoblast cell line C2C12. We also show that C2C12 cells secrete TGF-beta 3, and that this TGF-beta is able to inhibit C2C12 myoblast fusion after activation. In order to begin to understand how the TGF-beta 3 promoter is regulated in specific tissues during development, we therefore studied the regulation of TGF-beta 3 during myoblast fusion. After fusion of C2C12 cells into myotubes, TGF-beta 3 mRNA levels increased eightfold as a result of increased TGF-beta 3 transcription. TGF-beta 3 transcriptional regulation was studied in myoblasts and myotubes by transfection of chimeric TGF-beta 3/CAT promoter plasmids. Chloramphenicol acetyltransferase (CAT) activity was stimulated in myoblasts by several upstream regions between -301 and -47 of the TGF-beta 3 promoter and by the TGF-beta 3 5' untranslated region. CAT activity directed by the TGF-beta 3 promoter in myotubes was stimulated by a distinct upstream region located between -499 and -221. Therefore, the high level of TGF-beta 3 mRNA expression in muscle cells appears to be dependent on multiple regulatory events during different stages of myogenesis.


1991 ◽  
Vol 11 (1) ◽  
pp. 84-92
Author(s):  
A G Geiser ◽  
S J Kim ◽  
A B Roberts ◽  
M B Sporn

We have cloned and sequenced a mouse genomic transforming growth factor beta 1 (TGF-beta 1) DNA fragment that includes the 5' untranslated and regulatory regions of the gene. High-sequence homology with the human TGF-beta 1 gene (66% nucleotide identity in 2.7 kb of DNA upstream of the translational start site) suggested evolutionary conservation of transcriptional regulation for TGF-beta 1. The absence of TATA or CAAT box sequences but the presence of several Sp1-binding and AP-2-like sequences in the promoter region was noted, as previously reported for the human gene. Two transcriptional initiation sites separated by 290 bp were identified by S1 nuclease analysis; these corresponded to transcripts with 866 and 576 nucleotides of 5' untranslated leader sequence. S1 analysis of different mouse tissues indicated that the two transcripts were present in the same ratio even though the total level of TGF-beta 1 mRNA transcripts varied between tissues. Promoter activity adjacent to both transcriptional start sites was demonstrated by using chloramphenicol acetyltransferase fusion genes assayed in mouse AKR-2B fibroblast cells. Transcriptional activation of the promoter by the Ha-ras oncogene was also demonstrated. The minimal promoter constructs (113 and 104 bp 5' of the first and second transcriptional start sites, respectively) were sufficient for induction by Ha-ras. These studies characterize the 5' structure and basal promoter activity of the mouse TGF-beta 1 gene as well as the transcriptional activation of TGF-beta 1 by the Ha-ras oncogene.


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 10 (11) ◽  
pp. 5983-5990
Author(s):  
R E Wager ◽  
R K Assoian

12-Tetradecanoylphorbol-13-acetate (TPA)-induced differentiation of U937 promonocytes leads to a 30-fold increase in transforming growth factor beta 1 (TGF-beta 1) gene expression, and this effect results from a stabilized mRNA. Similar up-regulation was detected in TPA-treated K562 erythroblasts but was absent from cell lines that do not differentiate in response to TPA. Related studies in vitro showed that postnuclear extracts of U937 promonocytes contain a ribonuclease system that degrades TGF-beta 1 mRNA selectively and that this system is completely blocked by prior treatment of the cells with TPA. These data identify a new mechanism for regulating TGF-beta 1 mRNA levels and allow us to establish the overall basis for control of TGF-beta 1 gene expression by activation of protein kinase C. Our results also provide a new basis for understanding the long-term up-regulation of TGF-beta 1 gene expression that can accompany hematopoietic cell differentiation.


1992 ◽  
Vol 117 (2) ◽  
pp. 395-400 ◽  
Author(s):  
D Lindholm ◽  
E Castrén ◽  
R Kiefer ◽  
F Zafra ◽  
H Thoenen

Transforming growth factor-beta 1 (TGF-beta 1) has been shown to up-regulate the synthesis of nerve growth factor (NGF) in cultured rat astrocytes and in neonatal brain in vivo (Lindholm, D., B. Hengerer, F. Zafra, and H. Thoenen. 1990. NeuroReport. 1:9-12). Here we show that mRNA encoding TGF-beta 1 increased in rat cerebral cortex after a penetrating brain injury. The level of NGF mRNA is also transiently increased after the brain trauma, whereas that of brain-derived neurotrophic factor remained unchanged. In situ hybridization experiments showed a strong expression of TGF-beta 1 4 d after the lesion in cells within and in the vicinity of the wound. Staining of adjacent sections with OX-42 antibodies, specific for macrophages and microglia/brain macrophages, revealed a similar pattern of positive cells, suggesting that invading macrophages, and perhaps reactive microglia, are the source of TGF-beta 1 in injured brain. Both astrocytes and microglia express TGF-beta 1 in culture, and TGF-beta 1 mRNA levels in astrocytes are increased by various growth factors, including FGF, EGF, and TGF-beta itself. TGF-beta 1 is a strong inhibitor of astrocyte proliferation and suppresses the mitotic effects of FGF and EGF on astrocytes. The present results indicate that TGF-beta 1 expressed in the lesioned brain plays a role in nerve regeneration by stimulating NGF production and by controlling the extent of astrocyte proliferation and scar formation.


1993 ◽  
Vol 13 (6) ◽  
pp. 3588-3597 ◽  
Author(s):  
L Scotto ◽  
R K Assoian

Chimeric plasmids containing selected reporter coding domains and portions of the transforming growth factor beta 1 (TGF-beta 1) 3' untranslated region (UTR) were prepared and used to identify potential mechanisms involved in regulating the biosynthesis of TGF-beta 1. Transient transfections with core and chimeric constructs containing the chloramphenicol acetyltransferase (CAT) reporter showed that steady-state CAT mRNA levels were decreased two- to threefold in response to the TGF-beta 1 3' UTR. Interestingly, CAT activity was somewhat increased in the same transfectants. Thus, production of CAT protein per unit of mRNA was stimulated by the TGF-beta 1 3' UTR (approximately fourfold in three cell lines of distinct lineage). The translation-stimulatory effect of the TGF-beta 1 3' UTR suggested by these studies in vivo was confirmed in vitro by cell-free translation of core and chimeric transcripts containing the growth hormone coding domain. These studies showed that production of growth hormone was stimulated threefold by the TGF-beta 1 3' UTR. A deletion analysis in vivo indicated that the GC-rich domain in the TGF-beta 1 3' UTR was responsible for both the decrease in mRNA levels and stimulation of CAT activity-mRNA. We conclude that this GC-rich domain can have a bifunctional effect on overall protein expression. Moreover, the notable absence of this GC-rich domain in TGF-beta 2, TGF-beta 3, TGF-beta 4, and TGF-beta 5 indicates that expression of distinct TGF-beta family members can be differentially controlled in cells.


Blood ◽  
1990 ◽  
Vol 76 (3) ◽  
pp. 533-537 ◽  
Author(s):  
SM Greenberg ◽  
C Chandrasekhar ◽  
DE Golan ◽  
RI Handin

Megakaryocyte development is a carefully controlled process that is at least partially regulated by cytokines. Previous investigations of megakaryocyte development have focused primarily on defining growth factors that induce or enhance differentiation. In this study we demonstrate that a specific cytokine, transforming growth factor beta 1 (TGF beta 1), inhibits the phorbol myristate acetate (PMA)-induced differentiation of the Dami human megakaryocytic cell line. The addition of purified platelet TGF beta 1 inhibits PMA-induced endomitosis in a dose-dependent manner. Inhibition of endomitosis occurs with as little as 0.4 pmol/L TGF beta 1, is half-maximal at 6.4 pmol/L, and is maximal between 40 and 200 pmol/L TGF beta 1. Inhibition does not require other growth factors or nonmegakaryocytic cells. Removal of TGF beta 1 from the cultures decreases inhibition, suggesting that the continuous presence of TGF beta 1 is required and that its effects are reversible. This effect occurs even though the Dami cells constitutively express TGF beta 1 messenger RNA (mRNA) and the TGF beta 1 mRNA levels are increased by PMA. TGF beta 1 also has been shown to inhibit endomitosis during short-term culture of primary human megakaryocytes. These results suggest a model in which negative as well as positive regulatory factors modulate a critical stage of megakaryocyte development.


Sign in / Sign up

Export Citation Format

Share Document