摘要:

AbstractWe investigated the induction of tissue factor by lymphokines in human monoblastic leukemia cell lines (U937) and leukemic cells from AML (acute myelogenous leukemia) patients. After incubation for 24 h, IL-2 enhanced the intracellular tissue factor 15-fold with U937 cells, and GM-CSF enhanced it 6-fold. In contrast, other lymphokines, such as IL-1-α, IL-1-β, IL-3, IL-4 and G-CSF, did not affect the activity of tissue factor.The leukemic blasts, depleted of T-lymphocytes, taken from five out of 16 AML patients showed a 2.5-14-fold increase in the activity of tissue factor per cell following incubation with 200 u/ml of IL-2 for 72 h.The IL-2 induced tissue factor activity more markedly than GM-CSF. Tissue factor stimulation by IL-2 did not correlate with the expression of the IL-2 receptor,Tac, but correlated well with FAB classification of AML cells. IL-2 responders were found in M4 and M5 subtypes only, but not all M4/M5 leukemias responded to IL-2. These findings indicate that IL-2 can mediate the tissue factor induction in the monocytic type of AML and the effect is not mediated byTacreceptors. This may shed a new light on our understanding of hypercoagulability in acute monoblastic leukemia.

ISSN:0897-7194    

DOI:10.3109/08977199009011004

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractHC11 mouse mammary epithelial cells can undergo a limited functional differentiation in terms ofβ-casein synthesis in response to the combined action of dexamethasone and prolactin. Transforming growth factor-β(TGF-β) can inhibitβ-casein expression in HC11 cells in a dose-dependent manner. This effect is reversible and specific as shown by comparison with the effect of other growth factors. TGF-βalso inhibits DNA synthesis of HC11 cells.These findings suggest a possible role of TGF-βas an inhibitor of functional differentiation in the mammary gland.

ISSN:0897-7194    

DOI:10.3109/08977199009011005

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThe expression of transforming growth factor beta (TGF-β) was examined during the evolution of streptococcal cell wall (SCW)-induced hepatic granulomas in rats to evaluate the role of TGF-βin chronic inflammation progressing to fibrosis. As determined by immunocyto-chemistry, Kupffer cells rapidly expressed TGF-β1 following intraperitoneal (i.p.) injection of SCW, and TGF-βwas expressed by mononuclear phagocytes in the earliest cell aggregates as well as by mononuclear phagocytes within the capsule of mature lesions. Interestingly, apparent extracellular TGF-βwas observed in mature lesions at the interface of the capsule and the cellular core, a region of active fibrogenesis. Granulomas isolated 3, 6, and 12 weeks post-SCW injection elaborated nanogram (ng) quantities of latent and active TGF-βinto culture supernatants, and expressed high levels of 2.4 and 1.9 kb TGF-β1 transcripts. Expression of procollagen type I and III mRNAs were observed in parallel with the expression of the TGF-β1 transcripts. Thus, TGF-βis expressed throughout SCW-granuloma development, and, based on known bioactivities, it appears that TGF-βmediates, in part, the recruitment and activation of monocytes and fibroblasts and deposition of collagen in SCW-granulomas and likely other chronic inflammatory lesions progressing to fibrosis.

ISSN:0897-7194    

DOI:10.3109/08977199009011006

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractTransforming growth factor beta 1 (TGF-β1) and its closely related homologue, TGF-β2, rapidly induce growth factor gene expression by freshly isolated human peripheral blood monocytes. Within 3 h of exposure to TGF-β, mRNA species specific for interleukin-1 (IL-1β), tumor necrosis factor-α(TNF-α), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) were observed. By 14-18 h, cytokine bioactivity and protein were detected in the culture supernatants. Furthermore, not only TGF-β1, but also TGF-β2 mRNA are expressed constitutively in unstimulated monocytes. However, in response to exogenous TGF-β(βl orβ2), only TGF-β1 gene expression is upregulated, and the expression of TGF-β2 mRNA is unchanged. This selective autoinduction of TGF-β1 appears to be controlled at both transcriptional and post-transcriptional levels. These paracrine and autocrine activities of TGF-βsuggest potential mechanisms through which an inflammatory response can be initiated and amplified. In addition, the TGF-βenhancement of growth factor generation may promote fibrosis and angiogenesis relevant to physiological tissue repair as well as pathological fibrotic sequelae.

ISSN:0897-7194    

DOI:10.3109/08977199009011007

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractWe provide evidence that both covalent and non-covalent inhibitors of chymotrypsin-like activities inhibit the insulin-induced DNA replication, while the hormonal metabolic effects such as induction of tyrosine aminotransferase activity or increase of amino-acid transport remain unchanged. Besides, the protease inhibitors that we tested were without any effect on both the autocatalytic phosphorylation of insulin receptors and the tyrosine kinase activity towards poly(glutamate/tyrosine). The inhibitory effect of protease inhibitors on DNA synthesis was also visible when fibroblast growth factor (FGF) was used to commit cells in the proliferative cycle. This observation proves that the involvement of a putative protease is not restricted to the insulin mitogenic pathway. Finally, we observed that Fao cells totally escaped the inhibitory action of a covalent inhibitor of chymotrypsin after having been exposed to insulin for 10 h. We propose that a chymotrypsin-like activity is involved in the intracellular signalling leading to the proliferation of rat hepatoma cells up to a non-return point situated in the middle of G1(6-8 h).

ISSN:0897-7194    

DOI:10.3109/08977199009011008

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractbFGF was extracted from either mouse, rat and human cell lines or mouse, rat, bovine and human brain tissue and partially purified by cation exchange chromatography and heparin-affinity chromatography. When the heparin-affinity purified proteins were probed on Western blots with antisera against either a highly conserved internal bFGF sequence or recombinant 18 kDa bFGF, species-specific forms of bFGF were detected. bFGF proteins from rat and mouse sources were of apparent molecular weight 18 000, 21 500 and 22 000 whereas those from human sources were of 18 000, 22 500 and 24 000. Bovine bFGF proteins were similar to the multiple human bFGFs. The 22.5 kDa and 24 kDa proteins from human cells were also recognized by an antibody specific for the N-terminally extended forms of human bFGF, whereas this antibody failed to detect 18 kDa bFGF. We show that the differences in molecular weight between human and rat bFGFs are consistent with the predicted ATG (methionine) or alternative CTG (leucine) translational start sites in the 5' upstream sequences of bFGF cDNAs. In addition we show that, irrespective of the species of origin, the larger bFGF proteins may be separated from 18 kDa bFGF by Mono S chromatography.

ISSN:0897-7194    

DOI:10.3109/08977199009011009

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractMedium conditioned by mouse sarcoma 180 cells stimulates the growth of capillary endothelial cells. The growth factor produced by mouse sarcoma 180 cells is heparin-binding, dithiothreitol-sensitive, endothelial cell specific, and secreted into the medium. The characteristics of this mouse sarcoma-derived growth factor are very similar to those of vascular endothelial growth factor (VEGF) first described by Ferrara and Henzel (1989). The N-terminal amino acid sequences of the two growth factors are similar. Since the amino acid sequence of vascular permeability factor (VPF) is essentially identical to that of VEGF, a Western blot of mouse sarcoma 180-derived endothelial growth factor was probed with a polyclonal antibody raised against human VPF. This antibody reacted with several proteins of approximately 23 kDa, suggesting the presence of multiple forms of a VEGF-like protein. A full length cDNA probe for bovine VEGF reacted strongly with RNA isolated from mouse sarcoma 180 cells. We conclude that an endothelial growth factor found in conditioned medium from mouse sarcoma 180 cells is VEGF.

ISSN:0897-7194    

DOI:10.3109/08977199009011010

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractBasic fibroblast growth factor (bFGF) is a mitogenic polypeptide highly conserved between species, implicated in regenerative processes and present in all tissues examined. In the heart, bFGF is localized in association with nuclei, extracellular matrix and intercalated discs of cardiomyocytes. In this article is reported bFGF association with the intramuscular parasitic protozoanSarcocystis in situ, in bovine hearts, detected by indirect immunofluorescence. Parasitic cysts appear connected directly to specialized host cell junctions: bFGF provides structural continuity between parasitic cyst wall and myocyte intercalated discs. Other proteins associated with intercalated discs such as desmin or desmoplakin are not detected in the cysts. Association with Sarcocystis suggests a new role for bFGF in the context of parasitic invasion and establishment.

ISSN:0897-7194    

DOI:10.3109/08977199009011011

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractImmunoglobulins reactive against basic fibroblast growth factor (bFGF) were obtained from the serum of a single rabbit immunized against residues [1-24] of bFGF conjugated to keyhole limpet hemocyanin (KLH). Pure immunoglobulin preparations no. 1 and no. 2 were prepared using different affinity chromatography columns and preabsorption to KLH-coupled Sepharose for preparation no. 1. Both preparations no. 1 and no. 2 were specific for bFGF inin vitroassays. Competition with synthetic peptides suggests that preparations no. 1 and no. 2 recognize predominantly epitope(s) within residues [16-24]bFGF or residues [1-10]bFGF, respectively,in situFurthermore, no. 2 (but not no. 1) antibodies can react with tissue-(heparin-)-bound antigen. When used in indirect immunofluorescence for bFGF in frozen heart sections, preparation no. 1 stained predominantly muscle intercalated discs (IcDs); muscle nuclei were also stained, in an overall punctate fashion. Preparation no. 2 stained muscle nuclei strongly, in association with the nuclear envelope; it also stained basement-membrane associated bFGF. Differences in immunostaining were also observed in uterine smooth muscle and kidney sections but not in skeletal muscle. It is plausible that accessibility of various epitopes within the amino-terminal region depends strongly on the local interactions of bFGF. Our data illustrate the importance of using several different antibodies to localize bFGF in a tissue

ISSN:0897-7194    

DOI:10.3109/08977199009011012

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor