Stimulation of pro-α1(I) collagen by TGF-β1 in mesangial cells: role of the p38 MAPK pathway

2001 ◽  
Vol 280 (3) ◽  
pp. F495-F504 ◽  
Author(s):  
Beek Yoke Chin ◽  
Amir Mohsenin ◽  
Su Xia Li ◽  
Augustine M. K. Choi ◽  
Mary E. Choi
Keyword(s):  
P38 Mapk ◽  
Intracellular Signaling ◽  
Mesangial Cells ◽  
Mapk Pathway ◽  
Dominant Negative ◽  
Glomerular Mesangial Cells ◽  
Mapk Activation ◽  
Mapk Phosphorylation ◽  
Collagen Mrna

Transforming growth factor-β1(TGF-β1) is a potent inducer of extracellular matrix protein synthesis and a key mediator of renal fibrosis. However, the intracellular signaling mechanisms by which TGF-β1stimulates this process remain incompletely understood. In this report, we examined the role of a major stress-activated intracellular signaling cascade, belonging to the mitogen-activated protein kinase (MAPK) superfamily, in mediating TGF-β1 responses in rat glomerular mesangial cells, using dominant-negative inhibition of TGF-β1 signaling receptors. We first stably transfected rat glomerular mesangial cells with a kinase-deleted mutant TGF-β type II receptor (TβR-IIM) designed to inhibit TGF-β1 signaling in a dominant-negative fashion. Next, expression of TβR-IIM mRNA was confirmed by Northern analysis. Cell surface expression and ligand binding of TβR-IIM protein were demonstrated by affinity cross-linking with 125I-labeled-TGF-β1. TGF-β1 rapidly induced p38 MAPK phosphorylation in wild-type and empty vector (pcDNA3)-transfected control mesangial cells. Interestingly, transfection with dominant-negative TβR-IIM failed to block TGF-β1-induced p38 MAPK phosphorylation. Moreover, dominant-negative TβR-IIMfailed to block TGF-β1-stimulated pro-α1(I) collagen mRNA expression and cellular protein synthesis, whereas TGF-β1-induced extracellular signal-regulated kinase (ERK) 1/ERK2 activation and antiproliferative responses were blocked by TβR-IIM. In the presence of a specific inhibitor of p38 MAPK, SB-203580, TGF-β1 was unable to stimulate pro-α1(I) collagen mRNA expression in the control and TβR-IIM-transfected mesangial cells. Finally, we confirmed that both p38 MAPK activation and pro-α1(I) collagen stimulation were TGF-β1 effects that were abrogated by dominant-negative inhibition of TGF-β type I receptor. Thus we show first demonstration of p38 MAPK activation by TGF-β1 in mesangial cells, and, given the rapid kinetics, this TGF-β1 effect is likely a direct one. Furthermore, our findings suggest that the p38 MAPK pathway functions as a component in the signaling of pro-α1(I) collagen induction by TGF-β1 in mesangial cells.

Swimming stress in DN 14-3-3 mice triggers maladaptive cardiac remodeling: role of p38 MAPK

2007 ◽  
Vol 292 (3) ◽  
pp. H1269-H1277 ◽  
Author(s):  
Ken-ichi Watanabe ◽  
Meilei Ma ◽  
Ken-ichi Hirabayashi ◽  
Narasimman Gurusamy ◽  
Punniyakoti T. Veeraveedu ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
P38 Mapk ◽  
Cardiac Remodeling ◽  
Mapk Pathway ◽  
Left Ventricular ◽  
Dominant Negative ◽  
Checkpoint Control ◽  
Mapk Activation ◽  
Swimming Stress

It is generally believed that a mechanical signal initiates a cascade of biological events leading to coordinated cardiac remodeling. 14-3-3 family members are dimeric phosphoserine-binding proteins that regulate signal transduction, apoptotic, and checkpoint control pathways. To evaluate the molecular mechanism underlying swimming stress-induced cardiac remodeling, we examined the role of 14-3-3 protein and MAPK pathway by pharmacological and genetic means using transgenic mice with cardiac-specific expression of dominant-negative (DN) mutants of 14-3-3 (DN 14-3-3/TG) and p38α/β MAPK (DNp38α and DNp38β) mice. p38 MAPK activation was earlier, more marked, and longer in the myocardium of the TG group compared with that of the nontransgenic (NTG) group after swimming stress, whereas JNK activation was detected on day 5 and decreased afterward. In contrast, ERK1/2 was not activated after swimming stress in either group. Cardiomyocyte apoptosis, cardiac hypertrophy, and fibrosis were greatly increased in the TG group compared with those in the NTG group. Moreover, we found a significant correlation between p38 MAPK activation and apoptosis in the TG group. Furthermore, DN 14-3-3 hearts showed enhanced atrial natriuretic peptide expression. In contrast, DNp38α and DNp38β mice exhibited reduced mortality and increased resistance to cardiac remodeling after 28 days of swimming stress compared with TG and NTG mice. Besides, treatment with a p38 MAPK inhibitor, FR-167653, resulted in regression of cardiac hypertrophy and fibrosis and improvement in the survival rate in the TG group. These results indicate for the first time that 14-3-3 protein along with p38 MAPK plays a crucial role in left ventricular remodeling associated with swimming stress.

Endothelin signalling and regulation of protein kinases in glomerular mesangial cells

2002 ◽  
Vol 103 (s2002) ◽  
pp. 132S-136S ◽  
Author(s):  
Andrey SOROKIN ◽  
Marco FOSCHI ◽  
Michael J. DUNN
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Molecular Mechanisms ◽  
Mesangial Cells ◽  
Mapk Pathway ◽  
P38 Map Kinase ◽  
Dominant Negative ◽  
Glomerular Mesangial Cells ◽  
Calcium Dependent ◽  
Mitogen Activated Protein

The molecular mechanisms of endothelin (ET)-dependent activation of extracellular signal-regulated kinase (ERK)and p38 mitogen-activated protein (MAP) kinase were studied in rat and human renal glomerular mesangial cells. ET-1 induced a rapid and transient activation of Ras in renal mesangial cells, which was dependent upon the formation of the Shc/Grb2/Sos1 signalling complex and resulted in transient ERK activation. We have observed that Pyk2, a calcium-dependent cytoplasmic tyrosine kinase, was expressed in human renal mesangial cells and was tyrosine phosphorylated after ET-1 treatment. ET-1-induced activation of p38 MAPK pathway (but not ERK pathway) was inhibited in human and in rat glomerular mesangial cells expressing dominant-negative form of Pyk2, suggesting the engagement of Pyk2 in ET-1-mediated activation of p38 MAP kinase cascade. Contractive responsiveness of renal mesangial cells was shown to depend on activation of the p38 MAP kinases. Thus, p38 MAP kinase stimulation could perhaps partially account for ET-1 contractive properties, whereas ET-1-induced cell proliferation occurs primarily via Ras-dependent activation of the ERK.

scholarly journals Selective HDAC8 Inhibition Attenuates Isoproterenol-Induced Cardiac Hypertrophy and Fibrosis via p38 MAPK Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Tingwei Zhao ◽  
Hae Jin Kee ◽  
Liyan Bai ◽  
Moon-Ki Kim ◽  
Seung-Jung Kee ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Protein Expression ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Selective Inhibitor ◽  
Type I ◽  
H9c2 Cells ◽  
Mapk Phosphorylation ◽  
Exact Function

Histone deacetylase (HDAC) expression and enzymatic activity are dysregulated in cardiovascular diseases. Among Class I HDACs, HDAC2 has been reported to play a key role in cardiac hypertrophy; however, the exact function of HDAC8 remains unknown. Here we investigated the role of HDAC8 in cardiac hypertrophy and fibrosis using the isoproterenol-induced cardiac hypertrophy model system.Isoproterenol-infused mice were injected with the HDAC8 selective inhibitor PCI34051 (30 mg kg−1 body weight). Enlarged hearts were assessed by HW/BW ratio, cross-sectional area, and echocardiography. RT-PCR, western blotting, histological analysis, and cell size measurements were performed. To elucidate the role of HDAC8 in cardiac hypertrophy, HDAC8 knockdown and HDAC8 overexpression were also used. Isoproterenol induced HDAC8 mRNA and protein expression in mice and H9c2 cells, while PCI34051 treatment decreased cardiac hypertrophy in isoproterenol-treated mice and H9c2 cells. PCI34051 treatment also reduced the expression of cardiac hypertrophic markers (Nppa, Nppb, and Myh7), transcription factors (Sp1, Gata4, and Gata6), and fibrosis markers (collagen type I, fibronectin, and Ctgf) in isoproterenol-treated mice. HDAC8 overexpression stimulated cardiac hypertrophy in cells, whereas HDAC8 knockdown reversed those effects. HDAC8 selective inhibitor and HDAC8 knockdown reduced the isoproterenol-induced activation of p38 MAPK, whereas HDAC8 overexpression promoted p38 MAPK phosphorylation. Furthermore, p38 MAPK inhibitor SB203580 significantly decreased the levels of p38 MAPK phosphorylation, as well as ANP and BNP protein expression, induced by HDAC8 overexpression.Here we show that inhibition of HDAC8 activity or expression suppresses cardiac hypertrophy and fibrosis. These findings suggest that HDAC8 could be a promising target to treat cardiac hypertrophy and fibrosis by regulating p38 MAPK.

scholarly journals Fine-tuned regulation of the PGC-1α gene transcription by different intracellular signaling pathways

2011 ◽  
Vol 300 (3) ◽  
pp. E500-E507 ◽  
Author(s):  
Tao Hong ◽  
Jie Ning ◽  
Xuefeng Yang ◽  
Hui-Yu Liu ◽  
Jianmin Han ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
P38 Mapk ◽  
Gene Transcription ◽  
Intracellular Signaling ◽  
Insulin Response ◽  
P38 Map Kinase ◽  
Mapk Phosphorylation ◽  
Response Elements ◽  
Intracellular Signaling Pathways

It has previously been known that transcription of the PGC-1α gene can be either inhibited or stimulated by p38 MAP kinase (p38 MAPK). To determine whether p38 MAPK plays an inhibitory or stimulatory role in PGC-1α gene transcription, we further investigated the role of p38 MAPK in this study. Our results showed that the basal level of p38 MAPK phosphorylation was increased in gastrocnemius of mice under HFD and that p38 MAPK stimulated PGC-1α gene transcription in C2C12 myotubes. Our results also provided new mechanisms in myotubes that the p38 MAPK-induced PGC-1α gene transcription was mediated by CREB. In exploring the role of the Akt-dependent insulin signaling on PGC-1α gene transcription, we found that the basal Akt-dependent signaling was increased in gastrocnemius of mice under HFD. The p38 MAPK-induced PGC-1α gene transcription was prevented by insulin. Insulin suppression of PGC-1α gene transcription was neutralized by overexpression of the constitutively nuclear form of FoxO1. Finally, we located three insulin response elements (IREs) in the PGC-1α promoter, and mutations of these IREs abolish or blunt activity of the PGC-1α promoter. Together, our results show that transcription of the PGC-1α gene is balanced by different intracellular signaling pathways.

Relevant role of PKG in the progression of fibrosis induced by TNF-like weak inducer of apoptosis

2014 ◽  
Vol 307 (1) ◽  
pp. F75-F85 ◽  
Author(s):  
Paloma Martín ◽  
Inés Mora ◽  
M. Alicia Cortes ◽  
Laura Calleros ◽  
Andrea García-Jerez ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Matrix Protein ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Dominant Negative ◽  
Extracellular Matrix Protein ◽  
Potent Inducer ◽  
Ras Pathway ◽  
Expression And Activity

TNF-like weak inducer of apoptosis (TWEAK) is an inflammatory cytokine that activates the FGF-inducible 14 receptor. Both TWEAK and the FGF-inducible 14 receptor are constitutively expressed in the kidney. TWEAK has been shown to modulate several biological responses, such as inflammation, proliferation, differentiation, and apoptosis, that contribute to kidney injury. However, the role of TWEAK in fibrosis and TWEAK-activated intracellular signaling pathways remain poorly understood. We tested the hypothesis that TWEAK can be a potent inducer of renal fibrosis by increasing transforming growth factor (TGF)-β1 expression (a well-known switch in the fibrosis process) through PKG-I downregulation. We showed that in human mesangial cells, TWEAK increased TGF-β1 expression and activity, leading to higher levels of the extracellular matrix protein fibronectin and decreased PKG-I expression and activity via the Ras pathway. PKG-I activation with 8-bromo-cGMP, Ras inactivation with dominant negative Ras, or Ras pathway inhibition with the ERK1/2 inhibitor PD-98059 resulted in the prevention of TWEAK-induced TGF-β1 upregulation. In vivo, exogenous administration of TWEAK to wild-type mice downregulated kidney PKG-I and increased kidney TGF-β1 expression. These effects were blunted in H-Ras knockout mice. Together, these data demonstrate, for the first time, the key role of PKG-I in TGF-β1 induction by TWEAK in kidney cells.

scholarly journals β-Arrestin2 Is Critically Involved in CXCR4-mediated Chemotaxis, and This Is Mediated by Its Enhancement of p38 MAPK Activation

2002 ◽  
Vol 277 (51) ◽  
pp. 49212-49219 ◽  
Author(s):  
Yue Sun ◽  
Zhijie Cheng ◽  
Lan Ma ◽  
Gang Pei
Keyword(s):  
P38 Mapk ◽  
Stromal Cell ◽  
Cancer Metastasis ◽  
Mapk Pathway ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Mapk Activation ◽  
Endogenous Expression ◽  
Stromal Cell Derived Factor ◽  
Negative Mutant

Chemotaxis mediated by chemokine receptors such as CXCR4 plays a key role in lymphocyte homing and hematopoiesis as well as in breast cancer metastasis. We have demonstrated previously that β-arrestin2 functions to attenuate CXCR4-mediated G protein activation and to enhance CXCR4 internalization. Here we show further that the expression of β-arrestin2 in both HeLa and human embryonic kidney 293 cells significantly enhances the chemotactic efficacy of stromal cell-derived factor 1α, the specific agonist of CXCR4, whereas the suppression of β-arrestin2 endogenous expression by antisense or RNA-mediated interference technology considerably attenuates stromal cell-derived factor 1α-induced cell migration. Expression of β-arrestin2 also augmented chemokine receptor CCR5-mediated but not epidermal growth factor receptor-mediated chemotaxis, indicating the specific effect of β-arrestin2. Further analysis reveals that expression of β-arrestin2 strengthened CXCR4-mediated activation of both p38 MAPK and ERK, and the suppression of β-arrestin2 expression blocked the activation of two kinases. Interestingly, inhibition of p38 MAPK activation (but not ERK activation) by its inhibitors or by expression of a dominant-negative mutant of p38 MAPK effectively blocked the chemotactic effect of β-arrestin2. Expression of a dominant-negative mutant of ASK1 also exerted the similar blocking effect. The results of our study suggest that β-arrestin2 can function not only as a regulator of CXCR4 signaling but also as a mediator of stromal cell-derived factor 1α-induced chemotaxis and that this activity probably occurs via the ASK1/p38 MAPK pathway.

Antioxidant PDTC induces stromelysin expression in mesangial cells via a tyrosine kinase-AP-1 pathway

1996 ◽  
Vol 270 (5) ◽  
pp. F806-F811 ◽  
Author(s):  
T. Yokoo ◽  
M. Kitamura
Keyword(s):  
Tyrosine Kinase ◽  
Blot Analysis ◽  
Tyrosine Kinases ◽  
Mesangial Cells ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Pyrrolidine Dithiocarbamate ◽  
Glomerular Mesangial Cells ◽  
Nf Kappa B

We found that pyrrolidine dithiocarbamate (PDTC) induces the matrix metalloproteinase stromelysin in cultured glomerular mesangial cells. Although PDTC is a well-known inhibitor of nuclear factor-kappa B (NF-kappa B), this effect was independent of the NF-kappa B activity, since overexpression of a dominant negative mutant of p50 NF-kappa B subunit repressed activity of the kappa B site, whereas it failed to induce stromelysin. To elucidate the intracellular mechanisms involved, we focused on the role of activator protein 1 (AP-1), since its binding site, the 12-O-tetradecanoylphorbol 13-acetate (TPA) response element (TRE), is located in the 5'-flanking region of the stromelysin gene. Northern blot analysis revealed that PDTC upregulated expression of c-jun and c-fos before the expression of stromelysin. Transient transfection studies using a TRE-LacZ reporter plasmid elucidated that activity of AP-1 was significantly increased by PDTC. Stable transfection with a c-jun antisense cDNA or pretreatment with curcumin, a pharmacological inhibitor of c-Jun/AP-1, revealed that inactivation of AP-1 diminished the induction of stromelysin by PDTC. To identify the machinery involved upstream of AP-1 activation, the role of tyrosine kinases was investigated. Western blot analysis showed that PDTC induced phosphorylation of tyrosine kinases. Treatment of mesangial cells with tyrosine kinase inhibitors suppressed activation of AP-1 as well as induction of stromelysin by PDTC. These findings demonstrate that the antioxidant PDTC induces stromelysin expression via stimulation of the tyrosine kinase-AP-1 pathway independent of its suppressive action on NF-kappa B.

Role of the p38 MAPK Pathway in Induction of iNOS Expression in Human Leukocytes

2008 ◽  
Vol 56 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Ewa Jablonska ◽  
Wioletta Ratajczak ◽  
Jakub Jablonski
Keyword(s):  
P38 Mapk ◽  
Mapk Pathway ◽  
Inos Expression ◽  
Human Leukocytes ◽  
P38 Mapk Pathway

scholarly journals Somatostatin stimulates intestinal NHE8 expression via p38 MAPK pathway

2011 ◽  
Vol 300 (2) ◽  
pp. C375-C382 ◽  
Author(s):  
Chunhui Wang ◽  
Hua Xu ◽  
Huacong Chen ◽  
Jing Li ◽  
Bo Zhang ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Mapk Pathway ◽  
Somatostatin Receptor ◽  
Peptide Hormone ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein ◽  
D Cells ◽  
Human Intestinal Cells

Diarrhea is a common manifestation of gastrointestinal disorders. Diarrhea-induced losses of fluid and electrolyte could lead to dehydration and electrolyte imbalances, resulting in significant morbidity and mortality, especially in children living in developing countries. Somatostatin, a peptide hormone secreted by D-cells, plays an important role in regulating motility and intestinal Na+ absorption. Although octreotide, a somatostatin analog, is used to treat diarrhea, its mechanisms of action are unclear. Here we showed that octreotide increased brush-border membrane Na+/H+ exchanger 8 (NHE8) expression in the small intestine to the exclusion of other NHEs that participate in Na+ absorption. The same effect also occurred in human intestinal cells (Caco-2). We found that the increase of NHE8 expression by somatostatin required p38 mitogen-activated protein kinase (MAPK) activation. Furthermore, the somatostatin receptor SSTR2 antagonist CYN154806 could abolish somatostatin-induced NHE8 expression and p38 MAPK phosphorylation. Thus our data provided the first concrete evidence indicating that somatostatin stimulates intestinal Na+ absorption by increasing intestinal NHE8 expression through the SSTR2-p38 MAPK pathway.

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