Differential role of PTK, ERK and p38 MAPK in superoxide impairment of NMDA cerebrovasodilation

TC21(R-Ras2), a Ras-related GTPase with transforming potential similar to H-, K- and N-Ras, is implicated in the pathogenesis of human cancers. Transforming growth factor β (TGF-β), a cytokine that plays a significant role in modulating tumorigenesis, normally prevents uncontrolled cell proliferation but paradoxically induces proliferation in H-Ras-transformed cancer cells. Although TC21 activates some pathways that mediate cellular transformation by the classical Ras proteins, the mechanisms through which TC21 induces tumor formation and how TGF-β regulates TC21 transformed cells is not known. To better understand the role of TC21 in cancer progression, we overexpressed an activated G23V mutant of TC21 in a nontumorigenic murine mammary epithelial (EpH4) cell line. Mutant TC21-expressing cells were significantly more oncogenic than cells expressing activated G12V H-Ras both in vivo and in vitro. TC21-induced transformation and proliferation required activation of p38 MAPK, mTOR (the mammalian target of rapamycin), and phosphoinositide 3-kinase but not Akt/PKB. Transformation by TC21 rendered EpH4 cells insensitive to the growth inhibitory effects of TGF-β, and the soft agar growth of these cells was increased upon TGF-β stimulation. Despite losing responsiveness to TGF-β-mediated growth inhibition, both Smad-dependent and independent pathways remained intact in TC21-transformed cells. Thus, overexpression of active TC21 in EpH4 cells induces tumorigenicity through the phosphoinositide 3-kinase, p38 MAPK, and mTOR pathways, and these cells lose their sensitivity to the normal growth inhibitory role of TGF-β.

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Thymoquinone Inhibits Tumor Growth and Induces Apoptosis in a Breast Cancer Xenograft Mouse Model: The Role of p38 MAPK and ROS

PLoS ONE ◽

10.1371/journal.pone.0075356 ◽

2013 ◽

Vol 8 (10) ◽

pp. e75356 ◽

Cited By ~ 90

Author(s):

Chern Chiuh Woo ◽

Annie Hsu ◽

Alan Prem Kumar ◽

Gautam Sethi ◽

Kwong Huat Benny Tan

Keyword(s):

Breast Cancer ◽

Mouse Model ◽

Tumor Growth ◽

P38 Mapk ◽

Xenograft Mouse Model ◽

Breast Cancer Xenograft

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Role of the p38 MAPK signaling pathway in mediating interleukin-28A-induced migration of UMUC-3 cells

International Journal of Molecular Medicine ◽

10.3892/ijmm.2012.1064 ◽

2012 ◽

Vol 30 (4) ◽

pp. 945-952 ◽

Cited By ~ 19

Author(s):

SE-JUNG LEE ◽

WUN-JAE KIM ◽

SUNG-KWON MOON

Keyword(s):

Signaling Pathway ◽

P38 Mapk ◽

Mapk Signaling ◽

Mapk Signaling Pathway

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Abstract P231: Inhibition of Mir-762 Prevents and Reverses Ang II Induced Aortic Stiffening

Hypertension ◽

10.1161/hyp.68.suppl_1.p231 ◽

2016 ◽

Vol 68 (suppl_1) ◽

Author(s):

Kim Ramil C Montaniel ◽

Jing Wu ◽

Matthew R Bersi ◽

Liang Xiao ◽

Hana A Itani ◽

...

Keyword(s):

P38 Mapk ◽

Aortic Stiffness ◽

Fold Increase ◽

Organ Damage ◽

Locked Nucleic Acid ◽

Ang Ii ◽

New Approach ◽

Acid Inhibitor ◽

Aortic Stiffening

We and others have shown that hypertension (HTN) is linked with striking fibrosis in the aortic adventitia. This leads to aortic stiffening, leading to organ damage. Through a screen of microRNAs (miRNAs) in the aorta, we found that miR-762 is the most upregulated miRNA in Ang II hypertensive mice. qRT-PCR confirmed that miR-762 is upregulated 6.35±1.22 (p=0.03) fold in Ang II-infused mice compared to controls. To study the role of miR-762 in HTN, we administered a locked nucleic acid inhibitor of miR-762. MiR-762 inhibition normalized stress-strain relationships and aortic systolic energy storage (ASE) (Table). Moreover, miR-762 inhibition in the last 2 weeks of Ang II infusion reversed aortic stiffness in mice treated with 4 wk of Ang II (ASE, 4 wk Ang II [51±5.18 kPa] vs 4wk Ang II + LNA-762 (last 2 wk) [20±1.76 kPa], p<0.0001). Further studies showed that miR-762 inhibition reduced mRNA for several collagens and fibronectin and upregulated collagenases MMP1a, 8 and 13 (Table). Lastly, we found that miR-762 inhibition during Ang II infusion led to a 9.11±1.92 (p=0.007) fold increase in Sprouty1 mRNA, suggesting that miR-762 targets Sprouty1 mRNA. Sprouty1 inhibits the activation of p38-MAPK which is critical in the process of aortic stiffening. Hence, miR-762 modulates aortic stiffening and fibrosis through a Sprouty1-p38-MAPK mechanism. Thus, miR-762 has a major role in modulating aortic stiffening and its inhibition dramatically inhibits pathological fibrosis, enhances matrix degradation, prevents and reverses aortic stiffness. miR-762 inhibition might represent a new approach to prevent aortic stiffening and its consequent end-organ damage.

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Effect of selective inhibition of the p38 MAP kinase pathway on platelet aggregation

Thrombosis and Haemostasis ◽

10.1160/th04-03-0187 ◽

2004 ◽

Vol 92 (12) ◽

pp. 1387-1393 ◽

Cited By ~ 47

Author(s):

Athan Kuliopulos ◽

Ramon Mohanlal ◽

Lidija Covic

Keyword(s):

Platelet Aggregation ◽

P38 Mapk ◽

Coronary Intervention ◽

Selective Inhibition ◽

P38 Map Kinase ◽

Significant Inhibition ◽

Mitogen Activated Protein Kinase ◽

Thromboxane Production ◽

Mapk Inhibitor

SummarySystemic inflammation has been shown to be a contributing factor to the instability of atherosclerotic plaques in patients with acute coronary syndromes (ACS). VX-702, a novel p38 mitogen-activated protein kinase (MAPK) inhibitor, is currently under investigation in ACS patients with unstable angina to evaluate its safety and efficacy during percutaneous coronary intervention (PCI).The role of p38 MAPK in platelet aggregation of normal individuals was examined using the selective second generation p38 MAPK inhibitor VX-702. Treatment of platelets with thrombin (activates PAR1 and PAR4 thrombin receptors), SFLLRN (PAR1), AYPGKF (PAR4), collagen (α2β1 and GPVI/FCγIIR receptors) and U46619 (TXA2) resulted in strong activation of p38 MAPK. Activation of the GPIb von Willebrand factor receptor with ristocetin did not stimulate p38 MAPK. Pre-treatment of platelets with 1 μM VX-702 completely inhibited activation of p38 MAPK by thrombin, SFLLRN, AYPGKF, U46619, and collagen. There was no effect of VX-702 on platelet aggregation induced by any of the agonists in the presence or absence of aspirin, heparin or apyrase. It has been postulated that a potential role of p38 MAPK is to activate phospholipase A2 (cPLA2) which catalyses formation of arachidonic acid leading to production of thromboxane. Interestingly, we show contrasting effects of p38 MAPK inhibition as compared to aspirin inhibition on platelet aggregation in response to collagen. Blockade of TXA2 production by aspirin results in significant inhibition of collagen activation. However, VX-702 has no effect on collagen-mediated platelet aggregation, suggesting that blocking p38 MAPK does not effect thromboxane production in human platelets. Therefore, unlike aspirin blockade of thromboxane production in platelets, p38 MAPK inhibitors such as VX-702 do not significantly affect platelet function and would not be expected to contribute to an elevated risk of bleeding side-effects in treated patients.

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

AJP Renal Physiology ◽

10.1152/ajprenal.2001.280.3.f495 ◽

2001 ◽

Vol 280 (3) ◽

pp. F495-F504 ◽

Cited By ~ 92

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.

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