Bimodal effects of platelet-derived growth factor on rat mesangial cell proliferation and death, and the role of lysophosphatidic acid in cell survival

2001 ◽  
Vol 101 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Chiyoko N. INOUE ◽  
Isao NAGANO ◽  
Ryo ICHINOHASAMA ◽  
Natsumi ASATO ◽  
Yoshiaki KONDO ◽  
...  

Although mesangial cell death has been shown to be correlated with mesangial cell mitosis in vivo, little is known about how these two apparently opposite events are regulated. We show that the addition of platelet-derived growth factor (PDGF; 10–50 ng/ml) to primary cultured rat mesangial cells for 24 h caused continuous proliferation along with simultaneous cell death. This process was accompanied by the fragmentation of DNA into nucleosomal oligomers, the development of apoptotic morphological changes in the nucleus, and increased expression of p53. Accumulation of lactate dehydrogenase (LDH) was also observed in the culture medium, suggesting that both apoptosis and necrosis are involved in the cell death mechanisms observed. We also observed that addition of 30 µM lysophosphatidic acid (LPA) to the culture medium greatly suppressed PDGF-induced cell death, leading to synergistically enhanced mesangial cell proliferation. DNA fragmentation, p53 expression and LDH release were all suppressed by LPA. We suggest that PDGF is a bifunctional molecule in mesangial cells that evokes both cell proliferation and cell death simultaneously, whereas LPA is a survival factor. We speculate that PDGF and LPA may play important roles in the progression or exacerbation of proliferative glomerulonephritis.

1993 ◽  
Vol 85 (6) ◽  
pp. 747-751 ◽  
Author(s):  
R. J. D'Souza ◽  
H. M. Phillips ◽  
P. W. Jones ◽  
R. C. Strange ◽  
G. M. Aber

1. This study examined the influence of H2O2, interleukin-6 and platelet-derived growth factor on the proliferation of rat mesangial cells. Mesangial cells were exposed to either a single pulse or three daily pulses of H2O2 (10−8-10−4 mol/l), alone or in combination with interleukin-6 (5 ng/ml) and/or platelet-derived growth factor (10 ng/ml). Proliferation was assessed after 24 h and 72 h of incubation using [3H]thymidine incorporation and cell counts. 2. Although one pulse of H2O2 had no significant effect on mesangial cell proliferation, three daily pulses of 10−6 mol/l H2O2 resulted in a significant increase in [3H]thymidine incorporation of 31 (52.6, 10.3)% (median and 75th-25th interquartile range) (P <0.001). Both interleukin-6 and platelet-derived growth factor were also mitogenic to mesangial cells, [3H]thymidine incorporation increasing by 19 (36.7, −6.7)% (P <0.05) and 53.5 (107, 21.9)% (P <0.001), respectively. The mitogenic effect of interleukin-6 was enhanced by 10−6 mol/l H2O2 [49.9 (77.7, 12.3)%] (P <0.01), whereas the addition of 10−6 mol/l H2O2 to platelet-derived growth factor resulted in a summated increase in [3H]thymidine incorporation of 82.7 (113, 57.4)% (P <0.001). Incubation with all three substances simultaneously resulted in down-regulation of growth compared with H2O2 plus platelet-derived growth factor by 55.4 (77.7, 103)% (P <0.05). 3. These findings suggest that reactive oxygen species may play a major role in determining the mesangial cell proliferation that occurs in certain forms of glomerulonephritis, acting either alone or in combination with other growth factors.


1993 ◽  
Vol 4 (2) ◽  
pp. 119-128 ◽  
Author(s):  
R J Johnson ◽  
J Floege ◽  
W G Couser ◽  
C E Alpers

An approach for establishing a role for a growth factor in glomerular disease is presented. Using platelet-derived growth factor (PDGF) as an example, there is strong evidence to support the hypothesis that PDGF is a mediator of mesangial cell proliferation in glomerulonephritis. This includes evidence that (1) PDGF is a mitogen for mesangial cells in culture; (2) PDGF is expressed in both experimental and human glomerulonephritis in which mesangial cell proliferation occurs; (3) infusion of PDGF into rats induces mesangial cell proliferation and a hypercellular lesion; and (4) inhibition of PDGF in a model of experimental nephritis significantly reduces the mesangial cell proliferation. However, these data do not answer the question of whether or not the inhibition of PDGF in human diseases would be beneficial in the long term, because some cell proliferation is likely required for normal healing and repair. Further studies will be necessary to resolve this issue.


1995 ◽  
Vol 23 (6) ◽  
pp. 458-466 ◽  
Author(s):  
M S Razzaque ◽  
M Cheng ◽  
T Taguchi

Trapadil (Mochida Pharmaceuticals, Japan), an antiplatelet drug, suppresses the growth of several cell types and is thought to antagonize platelet-derived growth factor. The effects of trapidil on mesangial-cell proliferation in glomerulonephritis induced by anti-thymocyte serum in Wistar rats were investigated. Control rats were treated with phosphate-buffered saline (group I); group II rats were injected with a single dose of anti-thymocyte serum (8 ml/kg body weight), and group III rats were treated with both a single dose of anti-thymocyte serum (8 ml/kg body weight) and with trapidil (5 mg/kg body weight/day). Three rats in each group were killed on day 3, and the other three on day 10. Control rats showed no significant histological changes on day 3 or day 10. In group II, on day 3, there was a marked decrease in glomerular cell numbers, with mesangiolysis. Histologically severe mesangial-cell proliferation with expansion of mesangial areas was noted on day 10. None of the rats in group III showed mesangial alterations, histologically, indicating that mesangial-cell proliferation was suppressed by trapidil. This suppression may result from antagonism of the binding of platelet derived growth factor to the specific surface receptors in the mesangial cells. Trapidil may have clinical value in the treatment of mesangial-cell proliferative glomerular diseases.


2002 ◽  
Vol 13 (2) ◽  
pp. 322-331 ◽  
Author(s):  
Youichi Sugenoya ◽  
Ashio Yoshimura ◽  
Hisako Yamamura ◽  
Kiyoko Inui ◽  
Hiroyuki Morita ◽  
...  

ABSTRACT. The basic or h1 calponin gene, which encodes an actin-binding protein involved in the regulation of smooth-muscle shortening velocity, is known to be a smooth-muscle differentiation-specific gene. It was found that basic calponin was expressed by cultured mesangial cells and localized along the actin filaments. Among the growth factors involved in the mesangial cell pathophysiology, including platelet-derived growth factor-BB (PDGF-BB), tumor necrosis factor–α (TNF-α), and transforming growth factor–β1 (TGF-β1), TNF-α potently downregulates basic calponin expression in both the mRNA and protein levels, whereas TGF-β1 upregulates the calponin expression. PDGF-BB also reduced its mRNA expression. The half-life of basic calponin mRNA was determined to be similar between TNF-α–treated and –untreated mesangial cells, whereas cell transfection assays that used a luciferase reporter gene construct containing the functional basic calponin promoter showed that TNF-α and PDGF-BB reduced the transcriptional activity. Because stimulation with TNF-α and PDGF-BB was associated with mesangial cell proliferation, basic calponin may play a role in the suppression of mesangial cell proliferation. Treatment with anti–glomerular basement membrane antibody in calponin knockout mice induced more severe nephritis than in wild type mice, as judged from an increase in the urinary protein excretion, glomerular cellularity, and number of proliferating cell nuclear antigen–positive cells in glomerulus. These results suggest that basic calponin expression may serve as one of the intrinsic regulators of glomerular nephritis. Elucidation of the molecular mechanisms for regulation of the basic calponin expression in mesangial cells may improve the understanding of the molecular basis and pathogenesis of the glomerular response to injury.


1997 ◽  
Vol 8 (8) ◽  
pp. 1247-1256
Author(s):  
N I Neverov ◽  
G A Kaysen ◽  
R Nuccitelli ◽  
R H Weiss

Hypercholesterolemia and mesangial cell proliferation have been proposed to play a role in the progression of glomerulosclerosis in diabetic nephropathy and other renal diseases. Although LDL is mitogenic for and cytotoxic to mesangial cells, the effect of HDL on these cells is unknown. HDL stimulates fibroblast mitogenesis and is the principal cholesterol-bearing lipoprotein in the rat, the experimental model for studying the effect of hyperlipidemia on renal disease. Insulin is mitogenic in several cell systems, and its levels are increased in serum in non-insulin-dependent diabetes mellitus. This study investigates whether HDL acts as a growth factor in mesangial cells and whether it functions in parallel with insulin. It was found that HDL at protein concentrations between 10 and 500 microg/ml, both alone and in the presence of 100 nM insulin, increased DNA synthesis in mesangial cells (129 to 165% of control for HDL alone; 140 to 235% for HDL plus insulin), whereas HDL at 1000 microg/ml and greater inhibited mesangial cell proliferation. Insulin alone at 100 nM stimulated [3H]thymidine incorporation in the same cell system (145% of control); the mitogenic effect of insulin was additive to that of HDL. Purified apo A-I had a similar effect, but at significantly lower concentrations. Specific binding of HDL to mesangial cells was demonstrated (B(max) [binding constant] of 5.19 +/- 0.70 x 10(-7) micromol of HDL bound/mg cell protein and K(b) of 2.83 +/- 0.22 nM). Tetranitromethane alters apo A-I, preventing binding to its cognate receptor. Tetranitromethane-modified HDL did not bind to mesangial cells and had no effect on [3H]thymidine incorporation. Addition of HDL to mesangial cells caused an immediate transient increase in free intracellular calcium in several representative mesangial cells, similar to the response seen with platelet-derived growth factor. The mitogenic effect of HDL was not altered after attenuation of cellular protein kinase C activity, but the stimulatory effect of HDL alone and in combination with insulin on DNA synthesis was completely eliminated after inhibition of cellular tyrosine kinases by 24-h pretreatment with 0.25 microM herbimycin A. Thus, HDL binds to a specific apo A-I-dependent receptor, promotes DNA synthesis, and initiates second-messenger events by a tyrosine kinase-dependent and protein kinase C-independent mechanism.


1988 ◽  
Vol 255 (6) ◽  
pp. F1214-F1219 ◽  
Author(s):  
F. G. Conti ◽  
L. J. Striker ◽  
S. J. Elliot ◽  
D. Andreani ◽  
G. E. Striker

Mesangial cell proliferation is a common hallmark of many glomerular diseases. The exact mechanisms inducing cell proliferation in glomerulosclerosis are not completely understood, and it remains to be determined whether growth factors play a role in this process. Insulinlike growth factor I (IGF I) has been shown to be synthesized in the kidney, and glomerular mesangial cells have receptors for and exhibit mitogenic response to IGF I. We found that mouse glomerular mesangial cells in culture synthesized and released into the culture medium a molecule with immunological and biological features of IGF I. This molecule specifically bound to mesangial cell IGF I receptors; high-pressure liquid chromatographic analysis provided further evidence of its similarity to human recombinant IGF I. Mesangial cells released into the culture medium 6 ng/10(6) cells of IGF I-like material per 24 h in a time-dependent and actinomycin-D inhibitable fashion. These data suggest that IGF I might be locally released by mesangial cells in the glomerulus and act in an autocrine and paracrine fashion.


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