scholarly journals Captopril reverses high-glucose-induced growth effects on LLC-PK1 cells partly by decreasing transforming growth factor-beta receptor protein expressions.

1996 ◽  
Vol 7 (8) ◽  
pp. 1207-1215 ◽  
Author(s):  
J Y Guh ◽  
M L Yang ◽  
Y L Yang ◽  
C C Chang ◽  
L Y Chuang
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
High Glucose ◽  
Transforming Growth Factor ◽  
Receptor Protein ◽  
Tgf Beta ◽  
Beta Receptor ◽  
Protein Expressions ◽  
Beta Receptors ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta) may be important in the pathogenesis of diabetic nephropathy, and captopril is effective in treating this disorder. However, the mechanisms of this therapeutic effect as related to TGF-beta and its receptors are not known. Thus, the effects of captopril on cellular growth, TGF-beta 1, and TGF-beta receptors were studied in LLC-PK1 cells cultured in normal (11 mM) or high glucose (27.5 mM). This study found that glucose dose-dependently inhibited cellular mitogenesis while inducing hypertrophy in these cells at 72 h of culture, concomitantly with enhanced TGF-beta 1 messenger RNA (mRNA) and TGF-beta receptor Types I and II protein expressions. Captopril dose-dependently (0.1 to 10 mM) increased cellular mitogenesis and inhibited hypertrophy in these cells. Moreover, captopril also decreased TGF-beta receptor Types I and II protein expressions dose-dependently. However, TGF-beta 1 mRNA was not affected by captopril. It was concluded that high glucose decreased cellular mitogenesis while increasing hypertrophy concomitantly with increased TGF-beta 1 mRNA and TGF-beta receptors in LLC-PK1 cells. Captopril can reverse high-glucose-induced growth effects by decreasing TGF-beta receptor protein expressions.

scholarly journals The types II and III transforming growth factor-beta receptors form homo-oligomers.

1994 ◽  
Vol 126 (1) ◽  
pp. 139-154 ◽  
Author(s):  
Y I Henis ◽  
A Moustakas ◽  
H Y Lin ◽  
H F Lodish
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Type Ii ◽  
Tgf Beta ◽  
Double Labeling ◽  
Beta Receptors ◽  
Growth Factor Beta ◽  
In Cells

Affinity-labeling experiments have detected hetero-oligomers of the types I, II, and III transforming growth factor beta (TGF-beta) receptors which mediate intracellular signaling by TGF-beta, but the oligomeric state of the individual receptor types remains unknown. Here we use two types of experiments to show that a major portion of the receptor types II and III forms homo-oligomers both in the absence and presence of TGF-beta. Both experiments used COS-7 cells co-transfected with combinations of these receptors carrying different epitope tags at their extracellular termini. In immunoprecipitation experiments, radiolabeled TGF-beta was bound and cross-linked to cells co-expressing two differently tagged type II receptors. Sequential immunoprecipitations using anti-epitope monoclonal antibodies showed that type II TGF-beta receptors form homo-oligomers. In cells co-expressing epitope-tagged types II and III receptors, a low level of co-precipitation of the ligand-labeled receptors was observed, indicating that some hetero-oligomers of the types II and III receptors exist in the presence of ligand. Antibody-mediated cross-linking studies based on double-labeling immunofluorescence explored co-patching of the receptors at the cell surface on live cells. In cells co-expressing two differently tagged type II receptors or two differently tagged type III receptors, forcing one receptor into micropatches by IgG induced co-patching of the receptor carrying the other tag, labeled by noncross-linking monovalent Fab'. These studies showed that homo-oligomers of the types II and III receptors exist on the cell surface in the absence or presence of TGF-beta 1 or -beta 2. In cells co-expressing types II and III receptors, the amount of heterocomplexes at the cell surface was too low to be detected in the immunofluorescence co-patching experiments, confirming that hetero-oligomers of the types II and III receptors are minor and probably transient species.

scholarly journals Transforming growth factor-beta 1 in hypertensive renal injury in Dahl salt-sensitive rats.

1996 ◽  
Vol 7 (12) ◽  
pp. 2578-2589
Author(s):  
K Tamaki ◽  
S Okuda ◽  
M Nakayama ◽  
T Yanagida ◽  
M Fujishima
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Renal Injury ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Vascular Walls ◽  
Beta Receptors ◽  
Growth Factor Beta ◽  
Pai 1

The expression of transforming growth factor-beta 1 (TGF-beta 1) for hypertensive renal injury was investigated in Dahl salt-sensitive (Dahl-S) rats fed a high-salt (HS; 8% NaCl) diet or a low-salt (LS; 0.3% NaCl) diet for 4 wk. The HS rats developed severe hypertension and renal damage, including glomerulosclerosis and arteriosclerosis. TGF-beta biosynthesis by isolated glomeruli, the TGF-beta localization, and the gene expression of TGF-beta 1, latent TGF-beta binding protein (LTBP), and TGF-beta receptors (Types I, II, and III) were compared between the HS rats and LS rats. A TGF-beta bioassay revealed that the isolated glomeruli from the HS rats secreted a larger amount of latent TGF-beta than those from the LS rats. Northern blotting analysis demonstrated that the HS diet led to the increases in cortical gene expression of TGF-beta 1, LTBP, and TGF-beta receptors, compared with the LS diet. The glomerular biosynthesis of fibronectin and plasminogen activator inhibitor-1 (PAI-1), and cortical mRNA expression for fibronectin, collagen I, and PAI-1 (which may be affected by TGF-beta) in the HS rats were elevated, compared with the LS rats. The latent TGF-beta immunostained by anti-LTBP antibody was localized on the sclerosing glomeruli and vascular walls. Furthermore, fibronectin, collagen I, and PAI-1 were also localized in the sclerotic area. The TGF-beta 1-positive cells, immunostained by antibody for latency-associated peptide of TGF-beta 1, increased in the glomeruli and vascular walls in the HS rats. These results thus suggested that TGF-beta 1 may be related to hypertensive renal injury in this model.

scholarly journals A glycosylation-deficient endothelial cell mutant with modified responses to transforming growth factor-beta and other growth inhibitory cytokines: evidence for multiple growth inhibitory signal transduction pathways.

1993 ◽  
Vol 4 (2) ◽  
pp. 135-144 ◽  
Author(s):  
V Fafeur ◽  
B O'Hara ◽  
P Böhlen
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tnf Alpha ◽  
Type I ◽  
Tgf Beta ◽  
Ifn Gamma ◽  
Beta Receptor ◽  
Growth Inhibitory ◽  
Growth Factor Beta

An endothelial cell line (M40) resistant to growth inhibition by transforming growth factor-beta type 1 (TGF beta 1) was isolated by chemical mutagenesis and growth in the presence of TGF beta 1. Like normal endothelial cells, this mutant is characterized by high expression of type II TGF beta receptor and low expression of type I TGF beta receptor. However, the mutant cells display a type II TGF beta receptor of reduced molecular weight as a result of a general defect in N-glycosylation of proteins. The alteration does not impair TGF beta 1 binding to cell surface receptors or the ability of TGF beta 1 to induce fibronectin or plasminogen activator inhibitor-type I production. M40 cells were also resistant to growth inhibition by tumor necrosis factor alpha (TNF alpha) and interleukin-1 alpha (IL-1 alpha) but were inhibited by interferon-gamma (IFN gamma) and heparin. These results imply that TGF beta 1, TNF alpha, and IL-1 alpha act through signal transducing pathways that are separate from pathways for IFN gamma and heparin. Basic fibroblast growth factor was still mitogenic for M40, further suggesting that TGF beta 1, TNF alpha, and IL-1 alpha act by direct inhibition of cell growth rather than by interfering with growth stimulatory pathways.

scholarly journals Identification of a novel transforming growth factor-beta (TGF-beta 5) mRNA in Xenopus laevis.

1990 ◽  
Vol 265 (2) ◽  
pp. 1089-1093 ◽  
Author(s):  
P Kondaiah ◽  
M J Sands ◽  
J M Smith ◽  
A Fields ◽  
A B Roberts ◽  
...  
Keyword(s):  
Growth Factor ◽  
Xenopus Laevis ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Growth Factor Beta
Sign in / Sign up

Export Citation Format

Share Document