Mitogen-activated protein kinases ERK 1/2- and p38-GATA4 pathways mediate the Ang II-induced activation of FGF2 gene in neonatal rat cardiomyocytes

2011 ◽  
Vol 81 (4) ◽  
pp. 518-525 ◽  
Author(s):  
Wenjie Tang ◽  
Youzhen Wei ◽  
Kang Le ◽  
Zhi Li ◽  
Yingxia Bao ◽  
...  
2003 ◽  
Vol 284 (4) ◽  
pp. H1269-H1276 ◽  
Author(s):  
Pinggang Liu ◽  
Derek A. Misurski ◽  
Venkat Gopalakrishnan

With the use of fura 2 measurements in multiple and single cells, we examined whether cysteinyl leukotrienes (CysLT) mediate angiotensin II (ANG II)-evoked increases in cytosolic free Ca2+ concentration ([Ca2+]i) in neonatal rat cardiomyocytes. ANG II-evoked CysLT release peaked at 1 min. The angiotensin type 1 (AT1) antagonist losartan, but not the AT2antagonist PD-123319, attenuated the elevations in [Ca2+]i and CysLT levels evoked by ANG II. Vasopressin and endothelin-1 increased [Ca2+]i but not CysLT levels. The 5-lipoxygenase (5-LO) inhibitor AA-861 and the CysLT1-selective antagonist MK-571 reduced the maximal [Ca2+]i responses to ANG II but not to vasopressin and endothelin-1. While MK-571 reduced the responses to leukotriene D4 (LTD4), the dual CysLT antagonist BAY-u9773 completely blocked the [Ca2+]i elevation to both LTD4and LTC4. These data confirm that ANG II-evoked increases, but not vasopressin- and endothelin-1-evoked increases, in [Ca2+]i involve generation of the 5-lipoxygenase metabolite CysLT. The inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] antagonist 2-aminoethoxydiphenyl borate attenuated the [Ca2+]i responses to ANG II and LTD4. Thus AT1 receptor activation by ANG II is linked to CysLT-mediated Ca2+ release from Ins(1,4,5)P3-sensitive intracellular stores to augment direct ANG II-evoked Ca2+ mobilization in rat cardiomyocytes.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Guoliang Meng ◽  
Liping Xie ◽  
Yong Ji

Rationale: H 2 S is a gasotransmitter that regulates multiple cardiovascular functions. Krüppel-like transcription factor (KLF) exerts diverse functions in the cardiovascular system. Objectives: The aim of present study was to investigate the effect of hydrogen sulfide (H 2 S) on myocardial hypertrophy. Methods and results: Myocardial samples of 22 patients with left ventricle hypertrophy were collected and underwent histological and molecular biological analysis. Spontaneously hypertensive rats (SHR) and neonatal rat cardiomyocytes were studied for functional and signaling response to GYY4137, a H 2 S-releasing compound. Expression of cystathionine -lyase (CSE), a main enzyme for H 2 S generation in human heart, decreased in human hypertrophic myocardium, while KLF5 expression increased. In SHR treated with GYY4137 for 4 weeks, myocardial hypertrophy was inhibited as evidenced by improvement in cardiac structural parameters, heart mass index, size of cardiac myocytes and expression of atrial natriuretic peptide (ANP). Levels of oxidative stress and phosphorylation of mitogen-activated protein kinases were also decreased after H 2 S treatment. H 2 S diminished expression of the KLF5 in myocardium of SHR and in neonatal rat cardiomyocytes rendered hypertrophy by angiotensin II (Ang II). H 2 S also inhibited ANP promoter activity and ANP expression in Ang II-induced neonatal rat cardiomyocyte hypertrophy, and these effects were suppressed by KLF5 knockdown. KLF5 promoter activity was increased by Ang II stimulation, and this was reversed by H 2 S. H 2 S also decreased activity of specificity protein-1 (SP-1) binding to the KLF5 promoter and attenuated KLF5 nuclear translocation by Ang II stimulation. Conclusion: H 2 S attenuated myocardial hypertrophy, which might be related to inhibiting oxidative stress and decreasing ANP transcription activity in a KLF5-dependent manner.


2003 ◽  
Vol 81 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Gerd Wallukat ◽  
Dajana Neichel ◽  
Eberhard Nissen ◽  
Volker Homuth ◽  
Friedrich C Luft

We showed that sera from patients with preeclampsia contain autoantibodies directed against the angiotensin II AT1 receptor. The antibodies recognize an epitope on the second extracellular loop of the receptor and are immuno globulins of the IgG3 subclass. The antibodies accelerate the beating rate of neonatal rat cardiomyocytes. The agonistic effect can be blocked with the AT1 receptor blocker losartan and can be neutralized by a peptide corresponding to the AT1 receptor's second extracellular loop. In further studies we shown that the autoantibodies recognize a specific conformation of the AT1 receptor. Cleavage of the external disulfide bond with dithiothreitol caused an inactivation of the receptor when stimulated either with Ang II or the autoantibodies in a system of cultured neonatal rat cardiomyocytes. Long-term stimulation of the AT1 receptor with either agonists down-regulated the AT1 receptor-mediated response to a second Ang II stimulation. These observations show that the agonistic autoantibodies behave pharmacologically in a similar fashion to Ang II. We have found the autoantibodies in all women meeting the clinical criteria of preeclampsia and suggest that they may be important to the pathogenesis of the disease.Key words: angiotensin II, preeclampsia, autoantibodies, IgG subclasses, dithiotrietol, AT1 receptor.


2007 ◽  
Vol 39 (5) ◽  
pp. 351-363 ◽  
Author(s):  
Rajaa El Bekay ◽  
Gonzalo Alba ◽  
M Edith Reyes ◽  
Pedro Chacón ◽  
Antonio Vega ◽  
...  

AbstractAngiotensin II (Ang II) highly stimulates superoxide anion production by neutrophils. The G-protein Rac2 modulates the activity of NADPH oxidase in response to various stimuli. Here, we describe that Ang II induced both Rac2 translocation from the cytosol to the plasma membrane and Rac2 GTP-binding activity. Furthermore, Clostridium difficile toxin A, an inhibitor of the Rho-GTPases family Rho, Rac and Cdc42, prevented Ang II-elicited production, phosphorylation of the mitogen-activated protein kinases (MAPKs) p38, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase 1/2, and Rac2 activation. Rac2 GTPase inhibition by C. difficile toxin A was accompanied by a robust reduction of the cytosolic Ca2+ elevation induced by Ang II in human neutrophils. Furthermore, SB203580 and PD098059 act as inhibitors of p38MAPK and ERK1/2 respectively, wortmannin, an inhibitor of phosphatidylinositol-3-kinase, and cyclosporin A, a calcineurin inhibitor, hindered both translocation of Rac2 from the cytosol to the plasma membrane and enhancement of Rac2 GTP-binding elicited by Ang II. These results provide evidence that the activation of Rac2 by Ang II is exerted through multiple signalling pathways, involving Ca2+/calcineurin and protein kinases, the elucidation of which should be insightful in the design of new therapies aimed at reversing the inflammation of vessel walls found in a number of cardiovascular diseases.


Cardiology ◽  
2016 ◽  
Vol 135 (4) ◽  
pp. 203-215 ◽  
Author(s):  
Yuan Zhang ◽  
Li Su ◽  
Kun Zhang

Objective: Neuregulin receptor degradation protein-1 (Nrdp1) is a novel E3 ubiquitin ligase, and we have previously shown that overexpression of Nrdp1 increased cardiomyocyte injury. However, the role of Nrdp1 in myocardial hypertrophy is unclear. In the present study, we clarified the molecular mechanisms of angiotensin II (Ang II)-induced cardiomyocyte hypertrophy regulated by Nrdp1 based on genome-wide transcriptional analysis. Methods: Neonatal rat cardiomyocytes were infected with adenoviruses containing green fluorescent protein (Ad-GFP) or wild-type Nrdp1 (Ad-Nrdp1), and then treated with Ang II for 36 h. Detection of differentially expressed genes was achieved with an Affymetrix Rat Gene 2.0 Array and Cluster and Java TreeView software. Results and Conclusion: Microarray data analysis demonstrated that Nrdp1 overexpression affected the expression of 12,140 mRNA genes in Ang II-induced cardiomyocyte hypertrophy, including the upregulation of 12,044 and the downregulation of 96. Gene ontology and globe signal transduction network analysis showed that Nrdp1 affected the expression of many genes related to stimulus response, the cell receptor pathway, and cell growth. Pathway network analysis identified myocardial metabolism, DNA replication, and the cell cycle as the most important pathways targeted by Nrdp1. lncRNA-mRNA coexpression network analysis showed that two core lncRNAs, NONRATT057160 and NONRATT054243, were involved in cardiomyotrophy regulated by Nrdp1 in cardiomyocytes. Taken together, these data provide compelling clues for further exploration of the function of Nrdp1 in heart disease.


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