EndophilinA2 protects against angiotensin II-induced cardiac hypertrophy by inhibiting angiotensin II type 1 receptor trafficking in neonatal rat cardiomyocytes

2018 ◽  
Vol 119 (10) ◽  
pp. 8290-8303 ◽  
Author(s):  
Yun Liu ◽  
Huan-Jia Shen ◽  
Xin-Qiu-Yue Wang ◽  
Hai-Qi Liu ◽  
Ling-Yun Zheng ◽  
...  
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.


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1163
Author(s):  
Ui Jeong Yun ◽  
Dong Kwon Yang

Sinapic acid (SA) is a naturally occurring phenolic compound with antioxidant properties. It also has a wide range of pharmacological properties, such as anti-inflammatory, anticancer, and hepatoprotective properties. The present study aimed to evaluate the potential pharmacological effects of SA against hypertrophic responses in neonatal rat cardiomyocytes. In order to evaluate the preventive effect of SA on cardiac hypertrophy, phenylephrine (PE)-induced hypertrophic cardiomyocytes were treated with subcytotoxic concentrations of SA. SA effectively suppressed hypertrophic responses, such as cell size enlargement, sarcomeric rearrangement, and fetal gene re-expression. In addition, SA significantly inhibited the expression of mitogen-activated protein kinase (MAPK) proteins as pro-hypertrophic factors and protected the mitochondrial functions from hypertrophic stimuli. Notably, SA activated Sirt3, a mitochondrial deacetylase, and SOD2, a mitochondrial antioxidant, in hypertrophic cardiomyocytes. SA also inhibited oxidative stress in hypertrophic cardiomyocytes. However, the protective effect of SA was significantly reduced in Sirt3-silenced hypertrophic cardiomyocytes, indicating that SA exerts its beneficial effect through Sirt3/SOD signaling. In summary, this is the first study to reveal the potential pharmacological action and inhibitory mechanism of SA as an antioxidant against cardiac hypertrophy, suggesting that SA could be utilized for the treatment of cardiac hypertrophy.


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.


2018 ◽  
Vol 96 (4) ◽  
pp. 352-358
Author(s):  
Si Gao ◽  
Xue-ping Liu ◽  
Li-hua Wei ◽  
Jing Lu ◽  
Peiqing Liu

Cardiac hypertrophy often refers to the abnormal growth of heart muscle through a variety of factors. The mechanisms of cardiomyocyte hypertrophy have been extensively investigated using neonatal rat cardiomyocytes treated with phenylephrine. α-Enolase is a glycolytic enzyme with “multifunctional jobs” beyond its catalytic activity. Its possible contribution to cardiac dysfunction remains to be determined. The present study aimed to investigate the change of α-enolase during cardiac hypertrophy and explore its role in this pathological process. We revealed that mRNA and protein levels of α-enolase were significantly upregulated in hypertrophic rat heart induced by abdominal aortic constriction and in phenylephrine-treated neonatal rat cardiomyocytes. Furthermore, knockdown of α-enolase by RNA interference in cardiomyocytes mimicked the hypertrophic responses and aggravated phenylephrine-induced hypertrophy without reducing the total glycolytic activity of enolase. In addition, knockdown of α-enolase led to an increase of GATA4 expression in the normal and phenylephrine-treated cardiomyocytes. Our results suggest that the elevation of α-enolase during cardiac hypertrophy is compensatory. It exerts a catalytic independent role in protecting cardiomyocytes against pathological hypertrophy.


2016 ◽  
Vol 310 (8) ◽  
pp. H984-H994 ◽  
Author(s):  
Mohd Shahid ◽  
Ester Spagnolli ◽  
Laura Ernande ◽  
Robrecht Thoonen ◽  
Starsha A. Kolodziej ◽  
...  

Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.


2013 ◽  
Vol 24 (24) ◽  
pp. 3805-3818 ◽  
Author(s):  
Ali Pedram ◽  
Mahnaz Razandi ◽  
Ramesh Narayanan ◽  
James T. Dalton ◽  
Timothy A. McKinsey ◽  
...  

The development and progression of cardiac hypertrophy often leads to heart failure and death, and important modulators of hypertrophy include the histone deacetylase proteins (HDACs). Estrogen inhibits cardiac hypertrophy and progression in animal models and humans. We therefore investigated the influence of 17-β-estradiol on the production, localization, and functions of prohypertrophic (class I) and antihypertrophic (class II) HDACs in cultured neonatal rat cardiomyocytes. 17-β-Estradiol or estrogen receptor β agonists dipropylnitrile and β-LGND2 comparably suppressed angiotensin II–induced HDAC2 (class I) production, HDAC-activating phosphorylation, and the resulting prohypertrophic mRNA expression. In contrast, estrogenic compounds derepressed the opposite effects of angiotensin II on the same parameters for HDAC4 and 5 (class II), resulting in retention of these deacetylases in the nucleus to inhibit hypertrophic gene expression. Key aspects were confirmed in vivo from the hearts of wild-type but not estrogen receptor β (ERβ) gene–deleted mice administered angiotensin II and estrogenic compounds. Our results identify a novel dual regulation of cardiomyocyte HDACs, shown here for the antihypertrophic sex steroid acting at ERβ. This mechanism potentially supports using ERβ agonists as HDAC modulators to treat cardiac disease.


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