Transforming growth factor-beta-1 and interferon-beta are secreted by 3LL tumor cells and are chemotactic for lymphokine-activated killer (LAK) cells in vitro

1991 ◽  
Vol 27 ◽  
pp. S15
1992 ◽  
Vol 118 (3) ◽  
pp. 715-726 ◽  
Author(s):  
B A Arrick ◽  
A R Lopez ◽  
F Elfman ◽  
R Ebner ◽  
C H Damsky ◽  
...  

Transforming growth factor-beta (TGF-beta) is a potent mediator of cell proliferation and extracellular matrix formation, depending on the cell type and the physiological conditions. TGF-beta is usually secreted in a "latent" complex that needs activation before it can exert its effects. Several observations correlate increased expression of TGF-beta 1 with tumorigenesis. To evaluate the physiological relevance of increased TGF-beta 1 synthesis in tumor cells we established cell clones overexpressing TGF-beta 1 and observed the resulting physiological changes in TGF-beta overproducing cells in vitro and in vivo. As a model system we used the human E1A-transformed 293 tumor cells, which are insensitive to the direct growth modulatory effects of TGF-beta. The selection of this cell line allows an assessment of physiological alterations independent of TGF-beta induced proliferative changes. The use of two TGF-beta 1 expression vectors containing either the natural or a modified TGF-beta 1 precursor cDNA permitted the establishment of separate 293 cell lines overexpressing latent or active TGF-beta. Comparison of the resulting changes in glycolytic rate, adhesiveness and integrin and plasminogen activator expression established that, in vitro, both types of clones behaved similarly, indicating that expression of latent TGF-beta induces autocrine changes in the tumor cells and thus suggesting that some level of cell-associated activation occurs. TGF-beta overexpression resulted in an increased metabolic rate due to enhanced glycolysis, a property long associated with tumor cells. This increased glycolysis was not associated with altered proliferation. Cells overexpressing TGF-beta also displayed enhanced fibronectin mRNA and plasminogen activator synthesis and increased adhesiveness in vitro. They showed enhanced survival when plated sparsely on plastic in the absence of serum, and attached more readily to laminin. In addition, synthesis of several beta 1 integrins, in particular the alpha 1/beta 1, alpha 2/beta 1, and alpha 3/beta 1, all of which recognize laminin, were enhanced. Finally, cells overexpressing active TGF-beta, but not latent TGF-beta, also showed increased tumorigenicity in nude mice. Thus, an increase in endogenous TGF-beta synthesis confers several proliferation-independent phenotypic changes which may be of significance for the survival of the tumor cell inoculum or its subsequent growth, and for tumor formation and development. In the case of cells expressing active TGF-beta, the release of active TGF-beta into the vicinity of the tumor cells may also result in a more hospitable environment for tumor growth.


1991 ◽  
Vol 173 (3) ◽  
pp. 589-597 ◽  
Author(s):  
G Poli ◽  
A L Kinter ◽  
J S Justement ◽  
P Bressler ◽  
J H Kehrl ◽  
...  

The pleiotropic immunoregulatory cytokine transforming growth factor beta (TGF-beta) potently suppresses production of the human immunodeficiency virus (HIV), the causative agent of the acquired immunodeficiency syndrome, in the chronically infected promonocytic cell line U1. TGF-beta significantly (50-90%) inhibited HIV reverse transcriptase production and synthesis of viral proteins in U1 cells stimulated with phorbol myristate acetate (PMA) or interleukin 6 (IL-6). Furthermore, TGF-beta suppressed PMA induction of HIV transcription in U1 cells. In contrast, TGF-beta did not significantly affect the expression of HIV induced by tumor necrosis factor alpha (TNF-alpha). These suppressive effects were not mediated via the induction of interferon alpha (IFN-alpha). TGF-beta also suppressed HIV replication in primary monocyte-derived macrophages infected in vitro, both in the absence of exogenous cytokines and in IL-6-stimulated cultures. In contrast, no significant effects of TGF-beta were observed in either a chronically infected T cell line (ACH-2) or in primary T cell blasts infected in vitro. Therefore, TGF-beta may play a potentially important role as a negative regulator of HIV expression in infected monocytes or tissue macrophages in infected individuals.


1991 ◽  
Vol 173 (5) ◽  
pp. 1121-1132 ◽  
Author(s):  
R A Fava ◽  
N J Olsen ◽  
A E Postlethwaite ◽  
K N Broadley ◽  
J M Davidson ◽  
...  

We have studied the consequences of introducing human recombinant transforming growth factor beta 1 (hrTGF-beta 1) into synovial tissue of the rat, to begin to better understand the significance of the fact that biologically active TGF-beta is found in human arthritic synovial effusions. Within 4-6 h after the intra-articular injection of 1 microgram of hrTGF-beta 1 into rat knee joints, extensive recruitment of polymorphonuclear leukocytes (PMNs) was observed. Cytochemistry and high resolution histological techniques were used to quantitate the influx of PMNs, which peaked 6 h post-injection. In a Boyden chamber assay, hrTGF-beta 1 at 1-10 fg/ml elicited a chemotactic response from PMNs greater in magnitude than that evoked by FMLP, establishing that TGF-beta 1 is an effective chemotactic agent for PMNs in vitro as well as in vivo. That PMNs may represent an important source of TGF-beta in inflammatory infiltrates was strongly suggested by a demonstration that stored TGF-beta 1 was secreted during phorbol myristate acetate-stimulated degranulation in vitro. Acid/ethanol extracts of human PMNs assayed by ELISA contained an average of 355 ng of TGF/beta 1 per 10(9) cells potentially available for secretion during degranulation of PMNs. [3H]Thymidine incorporation in vivo and autoradiography of tissue sections revealed that widespread cell proliferation was triggered by TGF-beta 1 injection. Synovial lining cells and cells located deep within the subsynovial connective tissue were identified as sources of at least some of the new cells that contribute to TGF-beta 1-induced hyperplasia. Our results demonstrate that TGF-beta is capable of exerting pathogenic effects on synovial tissue and that PMNs may represent a significant source of the TGF-beta present in synovial effusions.


1993 ◽  
Vol 264 (1) ◽  
pp. L36-L42 ◽  
Author(s):  
E. M. Denholm ◽  
S. M. Rollins

Bleomycin-induced fibrosis in rodents has been used extensively as a model of human pulmonary fibrosis. The influx of monocytes observed during the early stages of fibrosis is at least partially regulated by the elaboration of chemotactic factors in the lung. Exposure of alveolar macrophages (AM phi) to bleomycin either in vivo or in vitro stimulated secretion of monocyte chemotactic activity (MCA). This MCA has been previously characterized as being primarily due to fibronectin fragments. The present experiments revealed that bleomycin also induced AM phi to secrete a second chemotactic factor, transforming growth factor-beta (TGF-beta). However, the TGF-beta secreted by macrophages was in latent form, since no TGF-beta activity was detected unless AM phi conditioned medium (CM) was acid-activated. After acidification, chemotactic activity in CM from AM phi stimulated with bleomycin in vitro was increased by 3.6, whereas activity in AM phi CM from fibrotic rats increased by 2 and that of a bleomycin-stimulated AM phi cell line increased by 1.6. This acid-activatable chemotactic activity was inhibited by antibody to TGF-beta. Bleomycin-stimulated AM phi s secreted significantly more TGF-beta than did unstimulated controls. Further, in vitro exposure of AM phi to bleomycin induced TGF-beta mRNA expression in a time- and concentration-dependent manner, with maximal mRNA being detected following a 16-h incubation with 1 microgram/ml bleomycin.


2019 ◽  
Vol 15 (66) ◽  
pp. 483
Author(s):  
SurapaneniKrishna Mohan ◽  
Murad Alsawalha ◽  
AbeerMohammed Al-Subaie ◽  
ReemYousuf Al-Jindan ◽  
SrinivasaRao Bolla ◽  
...  

2020 ◽  
Vol 9 (20) ◽  
Author(s):  
Yasushi Tashima ◽  
Hao He ◽  
Jason Z. Cui ◽  
Albert J. Pedroza ◽  
Ken Nakamura ◽  
...  

Background Male patients with Marfan syndrome have a higher risk of aortic events and root dilatation compared with females. The role androgens play during Marfan syndrome aneurysm development in males remains unknown. We hypothesized that androgens potentiate transforming growth factor beta induced Erk (extracellular‐signal‐regulated kinase)/Smad activation, contributing to aneurysm progression in males. Methods and Results Aortic diameters in Fbn1 C1039G/+ and littermate wild‐type controls were measured at ages 6, 8, 12, and 16 weeks. Fbn1 C1039G/+ males were treated with (1) flutamide (androgen receptor blocker) or (2) vehicle control from age 6 to 16 weeks and then euthanized. p‐Erk1/2, p‐Smad2, and matrix metalloproteinase (MMP) activity were measured in ascending/aortic root and descending aorta specimens. Fbn1 C1039G/+ male and female ascending/aortic root‐derived smooth muscle cells were utilized in vitro to measure Erk/Smad activation and MMP‐2 activity following dihydrotestosterone, flutamide or transforming growth factor beta 1 treatment. Fbn1 C1039G/+ males have increased aneurysm growth. p‐Erk1/2 and p‐Smad2 were elevated in ascending/aortic root specimens at age 16 weeks. Corresponding with enhanced Erk/Smad signaling, MMP‐2 activity was higher in Fbn1 C1039G/+ males. In vitro smooth muscle cell studies revealed that dihydrotestosterone potentiates transforming growth factor beta‐induced Erk/Smad activation and MMP‐2 activity, which is reversed by flutamide treatment. Finally, in vivo flutamide treatment reduced aneurysm growth via p‐Erk1/2 and p‐Smad2 reduction in Fbn1 C1039G/+ males. Conclusions Fbn1 C1039G/+ males have enhanced aneurysm growth compared with females associated with enhanced p‐Erk1/2 and p‐Smad2 activation. Mechanistically, in vitro smooth muscle cell studies suggested that dihydrotestosterone potentiates transforming growth factor beta induced Erk/Smad activation. As biological proof of concept, flutamide treatment attenuated aneurysm growth and p‐Erk1/2 and p‐Smad2 signaling in Fbn1 C1039G/+ males.


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