scholarly journals Platelet-derived growth factor and angiotensin II stimulate the mitogen-activated protein kinase cascade in renal mesangial cells: comparison of hypertrophic and hyperplastic agonists

1995 ◽  
Vol 305 (3) ◽  
pp. 777-784 ◽  
Author(s):  
A Huwiler ◽  
S Stabel ◽  
D Fabbro ◽  
J Pfeilschifter
Keyword(s):  
Angiotensin Ii ◽  
Growth Factor ◽  
Map Kinase ◽  
Mesangial Cell ◽  
Thymidine Incorporation ◽  
Mesangial Cells ◽  
Platelet Derived Growth Factor ◽  
Leucine Incorporation ◽  
Mitogen Activated Protein ◽  
Kinase Cascade

Exposure of mesangial cells to platelet-derived growth factor (PDGF) BB caused a significant stimulation of cell proliferation and protein synthesis, as measured by [3H]thymidine incorporation and [3H]leucine incorporation respectively. In contrast, cells treated with angiotensin II had no significant increase in [3H]thymidine incorporation, but demonstrated a marked increase in [3H]leucine incorporation. Furthermore, angiotensin II significantly increased total protein content per cell. These data show that, whereas PDGF-BB is a mitogen and stimulates mesangial-cell hyperplasia, angiotensin II causes hypertrophy of the cells without hyperplasia. Treatment of mesangial cells with PDGF and angiotensin II rapidly and dose-dependently stimulated mitogen-activated protein (MAP) kinase activity, as shown by an assay for activity in vitro using myelin basic protein as a substrate, and by immunoprecipitation of 32P-labelled cells with specific antibodies against the 42 kDa and 44 kDa mitogen-activated protein kinases p42mapk and p44mapk, respectively. Whereas stimulation with PDGF-BB caused a potent and sustained (for more than 30 min) phosphorylation and activation of p42mapk and p44mapk, as well as of the upstream activators MAP kinase kinase and c-Raf, the effect of angiotensin II was less potent, reaching a peak at 5-10 min and thereafter declining rapidly. In summary, these results suggest that PDGF-BB and angiotensin II differ in their potency and duration of activation of the MAP kinase cascade, which may explain why PDGF-BB is a potent mitogen for mesangial cells, whereas angiotensin II only triggers mesangial-cell hypertrophy.

scholarly journals Regulation of Rat Mesangial Cell Migration by Platelet-Derived Growth Factor, Angiotensin II, and Adrenomedullin

1999 ◽  
Vol 10 (12) ◽  
pp. 2495-2502 ◽  
Author(s):  
MASAKAZU KOHNO ◽  
KENICHI YASUNARI ◽  
MIEKO MINAMI ◽  
HIROAKI KANO ◽  
KENSAKU MAEDA ◽  
...  
Keyword(s):  
Cell Migration ◽  
Angiotensin Ii ◽  
Growth Factor ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Inhibitory Effect ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Concentration Dependent Manner

Abstract. This study sought to determine whether platelet-derived growth factor (PDGF) and angiotensin II (AngII) stimulate migration of cultured rat glomerular mesangial cells. After finding that this was so, the effects of adrenomedullin (ADM) and cAMP-elevating agents on basal and stimulated mesangial cell migration were examined. Two isoforms of PDGF, AB and BB, stimulated migration in a concentration-dependent manner between 1 and 50 ng/ml, while the AA isoform lacked significant effect. AngII modestly but significantly stimulated migration in a concentration-dependent manner between 10-7 and 10-6 mol/L. Rat ADM significantly inhibited the PDGF BB- and AngII-stimulated migration in a concentration-dependent manner between 10-8 and 10-7 mol/L. Inhibition by rat ADM was accompanied by an increase in cellular cAMP. cAMP agonists or inducers such as 8-bromo cAMP, forskolin, and prostaglandin I2 also significantly reduced the stimulated migration. H 89, a protein kinase A (PKA) inhibitor, attenuated the inhibitory effect of ADM, and a calcitonin gene-related peptide (CGRP) receptor antagonist, human CGRP (8-37), abolished the inhibitory effects of rat ADM. These results suggest that PDGF AB and BB as well as AngII stimulate rat mesangial cell migration and that ADM can inhibit PDGF BB- and AngII-stimulated migration, at least in part through cAMP-dependent mechanisms likely to involve specific ADM receptors with which CGRP interacts. The adenylate cyclase/cAMP/PKA system may be involved in the migration-inhibitory effect of ADM in these cells.

Interactions of Hydrogen Peroxide with Interleukin-6 and Platelet-Derived Growth Factor in Determining Mesangial Cell Growth: Effect of Repeated Oxidant Stress

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
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Interleukin 6 ◽  
Mesangial Cell ◽  
Thymidine Incorporation ◽  
Mesangial Cells ◽  
Platelet Derived Growth Factor ◽  
Growth Effect ◽  
Cell Counts ◽  
Mesangial Cell Proliferation

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.

scholarly journals Treatment of vascular smooth muscle cells with antisense phosphorothioate oligodeoxynucleotides directed against p42 and p44 mitogen-activated protein kinases abolishes DNA synthesis in response to platelet-derived growth factor

1996 ◽  
Vol 320 (1) ◽  
pp. 123-127 ◽  
Author(s):  
Caspar J. M. ROBINSON ◽  
Pamela H SCOTT ◽  
Andrew B ALLAN ◽  
Thomas JESS ◽  
Gwyn W. GOULD ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Map Kinase ◽  
Kinase Activity ◽  
Thymidine Incorporation ◽  
Muscle Cells ◽  
Platelet Derived Growth Factor ◽  
Mitogen Activated Protein

We have investigated the requirement for mitogen-activated protein (MAP) kinase in the stimulation of DNA synthesis by platelet-derived growth factor (PDGF) in rat aortic smooth muscle cells using a phosphorothioate-modified oligodeoxynucleotide (ODN) to deplete MAP kinase. Treatment for 72 h with MAP kinase antisense ODN directed against both the p42 and p44 isoforms of MAP kinase abolished the expression of MAP kinase and reduced agonist-stimulated MAP kinase activity by approx. 95%. The scrambled control ODN was without effect, but the sense control ODN slightly enhanced the expression of both isoforms. Abolition of MAP kinase activity by antisense ODN treatment prevented angiotensin II- and PDGF-stimulated activation of p90 ribosomal S6 kinase activity, but did not affect activation of MAP kinase kinase. In addition, antisense ODN pretreatment reduced PDGF-stimulated [3H]thymidine incorporation to < 5% of control, and decreased basal incorporation by approx. 90%. In contrast, basal [3H]thymidine incorporation was enhanced approx. 60% by control sense ODN treatment. These results indicate an obligatory role for MAP kinase in the activation of a number of early events in mitogenesis, including DNA synthesis, in vascular smooth muscle cells.

scholarly journals HDL causes mesangial cell mitogenesis through a tyrosine kinase-dependent receptor mechanism.

1997 ◽  
Vol 8 (8) ◽  
pp. 1247-1256
Author(s):  
N I Neverov ◽  
G A Kaysen ◽  
R Nuccitelli ◽  
R H Weiss
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase C ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Mesangial Cell ◽  
Thymidine Incorporation ◽  
Mesangial Cells ◽  
Mitogenic Effect ◽  
Kinase C ◽  
Mesangial Cell Proliferation

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.

The mitogen-activated protein kinase cascade is activated by B-Raf in response to nerve growth factor through interaction with p21ras

1994 ◽  
Vol 14 (10) ◽  
pp. 6944-6953
Author(s):  
R K Jaiswal ◽  
S A Moodie ◽  
A Wolfman ◽  
G E Landreth
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Map Kinase ◽  
Pc12 Cells ◽  
Mitogen Activated Protein Kinase ◽  
Stable Complex ◽  
Nerve Growth ◽  
Map Kinase Cascade ◽  
Mitogen Activated Protein ◽  
Kinase Cascade

Nerve growth factor (NGF) activates the mitogen-activated protein (MAP) kinase cascade through a p21ras-dependent signal transduction pathway in PC12 cells. The linkage between p21ras and MEK1 was investigated to identify those elements which participate in the regulation of MEK1 activity. We have screened for MEK activators using a coupled assay in which the MAP kinase cascade has been reconstituted in vitro. We report that we have detected a single NGF-stimulated MEK-activating activity which has been identified as B-Raf. PC12 cells express both B-Raf and c-Raf1; however, the MEK-activating activity was found only in fractions containing B-Raf. c-Raf1-containing fractions did not exhibit a MEK-activating activity. Gel filtration analysis revealed that the B-Raf eluted with an apparent M(r) of 250,000 to 300,000, indicating that it is present within a stable complex with other unidentified proteins. Immunoprecipitation with B-Raf-specific antisera quantitatively precipitated all MEK activator activity from these fractions. We also demonstrate that B-Raf, as well as c-Raf1, directly interacted with activated p21ras immobilized on silica beads. NGF treatment of the cells had no effect on the ability of B-Raf or c-Raf1 to bind to activated p21ras. These data indicate that this interaction was not dependent upon the activation state of these enzymes; however, MEK kinase activity was found to be associated with p21ras following incubation with NGF-treated samples at levels higher than those obtained from unstimulated cells. These data provide direct evidence that NGF-stimulated B-Raf is responsible for the activation of the MAP kinase cascade in PC12 cells, whereas c-Raf1 activity was not found to function within this pathway.

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 ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Growth Factor ◽  
Lysophosphatidic Acid ◽  
Culture Medium ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Platelet Derived Growth Factor ◽  
P53 Expression ◽  
Mesangial Cell Proliferation

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.

scholarly journals Inhibitory effects of adiponectin on platelet-derived growth factor-induced mesangial cell migration

2009 ◽  
Vol 202 (2) ◽  
pp. 309-316 ◽  
Author(s):  
Keisuke Ishizawa ◽  
Narantungalag Dorjsuren ◽  
Yuki Izawa-Ishizawa ◽  
Rika Sugimoto ◽  
Yasumasa Ikeda ◽  
...  
Keyword(s):  
Cell Migration ◽  
Growth Factor ◽  
Map Kinase ◽  
Intracellular Signaling ◽  
Mesangial Cell ◽  
Kinase Inhibitor ◽  
P38 Map Kinase ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Plasma Adiponectin

Adiponectin, an adipocyte-derived hormone, has been involved in metabolic syndrome, a known risk factor for the development of chronic kidney disease (CKD). Recent studies have demonstrated that plasma adiponectin levels are elevated when kidney function declines in patients with CKD. Excessive mesangial cell (MC) turnover is one of the important features of CKD. The aim of the present study is to elucidate the effects of adiponectin on platelet-derived growth factor (PDGF)-induced cell migration and intracellular signaling pathways, in cultured rat MCs (RMCs). PDGF-induced RMC migration was significantly inhibited by the pretreatment of adiponectin. Adiponectin alone had no effect on RMC migration. Big mitogen-activated protein (MAP) kinase 1 (BMK1), p38 MAP kinase, and Akt were activated by PDGF stimulation in a time- and concentration-dependent manner in RMC. Adiponectin alone did not affect BMK1, p38 MAP kinase, and Akt phosphorylations in RMC. PDGF-induced BMK1 and p38 MAP kinase phosphorylations were significantly attenuated by the pretreatment of adiponectin in RMCs. On the other hand, the phosphorylation of Akt by PDGF was not diminished by the pretreatment of adiponectin. Adiponectin had no effects on PDGF-receptor autophosphorylation by PDGF. We also confirmed that PDGF-induced RMC migration was significantly suppressed by siBMK1 transfection or SB203580, a p38 MAP kinase inhibitor. From these findings, it is implied that the elevated plasma adiponectin levels in patients with CKD might play a compensatory role aimed at counteracting renal dysfunction related to MC disorders.

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