scholarly journals BMP type I receptor ALK2 is required for angiotensin II-induced cardiac 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.

Author(s):  
Xilan Tang ◽  
Tracey Gan ◽  
Chian Ju Jong ◽  
Venkatesh Rajapurohitam ◽  
Morris Karmazyn

We determined whether North American ginseng mitigates the effect of angiotensin II on hypertrophy and heart failure. Angiotensin II (0.3 mg/kg) was administered to rats for 2 or 4 weeks in the presence or absence of ginseng pretreatment. The effect of ginseng (10 μg/mL) on angiotensin II (100 nM) induced hypertrophy was also determined in neonatal rat ventricular myocytes. We also determined effects of ginseng on fatty acid and glucose oxidation by measuring gene and protein expression levels of key factors. Angiotensin II treatment for 2 and 4 weeks induced cardiac hypertrophy as evidenced by increased heart weights as well as the upregulation of the hypertrophy-related fetal gene expression levels with all effects being abolished by ginseng. Ginseng also reduced abnormalities in left ventricular function as well as the angiotensin-induced increased blood pressure. In myocytes, ginseng abolished the hypertrophic response to angiotensin II as assessed by surface area and gene expression of molecular markers of hypertrophy. Ginseng modulated angiotensin II-induced abnormalities in gene expression and protein levels of CD36, CPT1M, Glut4 and PDK4 in vivo and in vitro. In conclusion, ginseng suppresses angiotensin II induced cardiac hypertrophy and dysfunction which is related to normalization of fatty acid and glucose oxidation.


2006 ◽  
Vol 290 (1) ◽  
pp. H279-H285 ◽  
Author(s):  
Xiuhua Liu ◽  
Tianbo Li ◽  
Sheng Sun ◽  
Feifei Xu ◽  
Yiguang Wang

Myofibrillogenesis regulator-1 (MR-1) is a novel homologous gene, identified from a human skeletal muscle cDNA library, that interacts with contractile proteins and exists in human myocardial myofibrils. The present study investigated MR-1 protein expression in hypertrophied myocardium and MR-1 involvement in cardiac hypertrophy. Cardiac hypertrophy was induced by abdominal aortic stenosis (AAS) in Sprague-Dawley rats. Left ventricular (LV) hypertrophy was assessed by the ratio of LV wet weight to whole heart weight (LV/HW) or LV weight to body weight (LV/BW). Rat MR-1 (rMR-1) expression in the myocardium was detected by immunohistochemical and Western blotting analysis. Hypertrophy was induced by ANG II incubation in cultured neonatal rat cardiomyocytes. The effect of rMR-1 RNA interference on ANG II-induced hypertrophy was studied by transfection of cardiomyocytes with an RNA interference plasmid, pSi-1, which targets rMR-1. Hypertrophy in cardiomyocytes was assessed by [3H]Leu incorporation and myocyte size. rMR-1 protein expression in cardiomyocytes was detected by Western blotting. We found that AAS resulted in a significant increase in LV/HW and LV/BW: 89% and 86%, respectively ( P < 0.01). Immunohistochemistry and Western blot analysis demonstrated upregulated rMR-1 protein expression in hypertrophic myocardium. ANG II induced a 24% increase in [3H]Leu incorporation and a 65.8% increase in cell size compared with control cardiomyocytes ( P < 0.01), which was prevented by treatment with losartan, an angiotensin (AT1) receptor inhibitor, or transfection with pSi-1. rMR-1 expression increased in ANG II-induced hypertrophied cardiomyocytes, and pSi-1 transfection abolished the upregulation. These findings suggest that MR-1 is associated with cardiac hypertrophy in rats in vivo and in vitro.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Daniel N Meijles ◽  
Michelle A Hardyman ◽  
Stephen J Fuller ◽  
Kerry A Rostron ◽  
Sam J Leonard ◽  
...  

Introduction: ERK1/2 promote hypertrophy and are protective in the heart, but cause cancer in dividing cells. Raf kinases lie upstream of ERK1/2 and Raf inhibitors (e.g. SB590885 (SB), dabrafenib (Dab)) are in development/use for cancer. Paradoxically, in cancer cells, low concentrations of SB/Dab stimulate (rather than inhibit) ERK1/2. Hypothesis: Our hypothesis is that the heart is primed for Raf paradox signaling. Raf inhibitors have potential to activate ERK1/2 in cardiomyocytes and promote cardiac hypertrophy. Methods: Neonatal rat ventricular cardiomyocytes (NRVMs) were exposed to inhibitors. Dab or SB (3 or 0.5 mg/kg/d) were studied in 12 wk male C57Bl6 mice in vivo in the presence of angiotensin II (AngII, 0.8 mg/kg/d) (n=6-11) using osmotic minipumps. Effects were compared with vehicle controls. Echocardiography was performed (Vevo2100). M-mode images (short axis view) were analyzed; data for each mouse were normalized to the mean of 2 baseline controls. Kinase activities were assessed by immunoblotting or in vitro kinase assays. Results: SB (0.1 μM) or Dab (1 μM) activated ERK1/2 (2.3±0.1 fold; n=4) in NRVMs consistent with Raf paradox signaling. An explanation is that Raf kinases dimerise and submaximal inhibitor concentrations bind one Raf protomer, locking it in an active conformation but activating the partner. In accord with this, 0.1 μM SB increased Raf activities. High SB concentrations (1-10 μM) initially inhibited ERK1/2 in NRVMs, but ERK1/2 were then activated (1 - 24 h) and promoted hypertrophy. In vivo (24 h), Dab and SB activated the ERK1/2 cascade, increasing ANF (17.3 ± 3.1 fold) and BNP (4.5 ± 0.8 fold) mRNA (n=4/5). Over 3 d, Dab and SB increased fractional shortening in the presence of AngII (1.22±0.06; 1.17±0.08), relative to AngII alone (0.95±0.04), increased systolic left ventricular (LV) wall thickness, and reduced systolic LV volume and internal diameter (0.83±0.03 cf 0.97±0.02 for AngII alone). Conclusions: The heart is primed for Raf paradox signaling and Raf inhibitors activate ERK1/2 in cardiomyocytes, promoting hypertrophy. In vivo, Raf inhibitors enhance ERK1/2 signaling and hypertrophy in the context of hypertension, and cardiac hypertrophy may be increased in hypertensive cancer patients receiving Raf inhibitors.


Endocrinology ◽  
2010 ◽  
Vol 151 (2) ◽  
pp. 830-838 ◽  
Author(s):  
Miriam van Dijk-Ottens ◽  
Ingrid H. C. Vos ◽  
Peter W. A. Cornelissen ◽  
Alain de Bruin ◽  
Maria E. Everts

The mechano growth factor (MGF), a splice variant of the IGF-I gene, was first discovered in mechanically overloaded skeletal muscle and was shown to play an important role in proliferation of muscle stem cells. Since then, the presence and effects of MGF have been demonstrated in other tissues. MGF has been shown to act neuroprotectively during brain ischemia, and pretreatment with MGF before myocardial infarction improves cardiac function. Because MGF plays a permissive role in exercise-induced skeletal muscle hypertrophy, we hypothesize that MGF is commonly involved in cardiac hypertrophy. To investigate the regulation of MGF expression in heart, mice were treated with thyroid hormone (T3) for 12 d to induce physiological cardiac hypertrophy. MGF mRNA expression was specifically increased in midregions of the septum and left ventricular wall. Interestingly, MGF expression strongly correlated with the increased or decreased beating frequency of hyperthyroid and hypothyroid hearts. To further investigate the mechanically dependent induction of MGF, neonatal rat cardiomyocytes were isolated and exposed to T3. Upon T3 treatment, cardiomyocytes increased both contractile activity measured as beats per minute and MGF as well as IGF-IEa mRNA expression. Importantly, when cardiomyocytes were contractile arrested by KCl, simultaneous exposure to T3 prevented the up-regulation of MGF, whereas IGF-IEa was still induced. These studies demonstrated that MGF but not IGF-IEa expression is dependent on beating activity. These findings suggest that MGF is specifically stimulated by mechanical loading of the heart to mediate the hypertrophic response to thyroid hormone.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Watanabe ◽  
T Narumi ◽  
T Watanabe ◽  
T Aono ◽  
J Goto ◽  
...  

Abstract Background Left ventricular reverse remodeling (LVRR) contributes to better outcomes in patients with non-ischemic cardiomyopathy (NICM). It is reported that LVRR is associated with progression of cardiac fibrosis. MicroRNAs (miRs) have emerged as powerful regulators of post-transcriptional gene expression. We focused on miR-21, which plays a key role in pathogenesis of fibrosis in multiple organs. The aim of this study was to clarify the effect of miR-21 on cardiac fibrosis and LVRR in patients with NICM. Methods We measured plasma miR-21 levels in 16 patients with NICM. LVRR was defined as increased LVEF by ≥10% and decreased LV end-diastolic diameter index by ≥10% from baseline data after optimal medication treatment at 1-year of follow-up. Further, we examined miR-21 expression and its potential role in cardiac fibrosis induced by transverse aortic constriction (TAC) in mice and angiotensin II (Ang II) stimulation in neonatal rat cardiomyocytes (NRCMs). Results There were 12 patients without LVRR and 4 patients with LVRR. Plasma miR-21 levels were significantly higher in patients without LVRR compared with those with LVRR. In TAC mice heart, miR-21 levels were significantly increased and programmed cell death 4 (PDCD4), a main target of miR-21, was decreased. In vitro, miR-21 levels were significantly increased and its upstream transcriptional factor, activator protein 1 (AP-1), was activated by Ang II stimulation in NRCMs. After transfection of miR-21 specific inhibitor, PDCD4 levels were upregulated. Furthermore, AP-1 activity, expression of collagen type I, and α-smooth muscle actin levels were significantly decreased after miR-21 inhibition. Conclusions These findings suggested that miR-21/PDCD4/AP-1 feedback loop pathway was involved in LVRR in patients with NICM by promoting cardiac fibrosis. MiR-21 can be the therapeutic target in NICM.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Cory Parks ◽  
Ryan D Sullivan ◽  
Salvatore Mancarella

Stromal Interaction Protein 1 (STIM1) is the intracellular component of the store operated calcium channels. It is a ubiquitous Ca2+ sensor, prevalently located in the sarcoplasmic reticulum. In non-excitable cells, STIM1 is a key element in the generation of Ca2+signals that lead to gene expression and cell proliferation. A growing body of literature now suggests that STIM1 is important for normal heart function and plays a key role in the development of pathological cardiac hypertrophy. However, the precise mechanisms involving STIM1 and the Ca2+ signaling in excitable cells are not clearly established. We show that in neonatal rat cardiomyocytes, the spatial properties of STIM1-dependent Ca2+ signals determine restricted Ca2+ microdomains that regulate myofilaments remodeling and spatially segregated activation of pro-hypertrophic factors. Indeed, in vivo data obtained from an inducible cardiac restricted STIM1 knockout mouse, exhibited left ventricular dilatation associated with reduced cardiac contractility, which was corroborated by impaired single cell contractility. Furthermore, mice lacking STIM1 showed less adverse structural remodeling in response to pathological pressure overload-induced cardiac hypertrophy (transverse aortic constriction, TAC). We further show that the Ca2+ pool associated with STIM1 is the ON switch for extracellular signal-regulated kinase (ERK1/2)-mediated cytoplasm to nucleus signaling. These results highlight how STIM1-dependent Ca2+ microdomains have a major impact on intracellular Ca2+ homeostasis, cytoskeletal remodeling, signaling and cardiac function, even when excitation-contraction coupling is present.


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.


2019 ◽  
Vol 116 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Hairuo Lin ◽  
Yang Li ◽  
Hailin Zhu ◽  
Qiancheng Wang ◽  
Zhenhuan Chen ◽  
...  

Abstract Aims Proton pump inhibitors (PPIs) are widely used in patients receiving percutaneous coronary intervention to prevent gastric bleeding, but whether PPIs are beneficial for the heart is controversial. Here, we investigated the effects of lansoprazole on cardiac hypertrophy and heart failure, as well as the underlying mechanisms. Methods and results Adult male C57 mice were subjected to transverse aortic constriction (TAC) or sham surgery and then were treated with lansoprazole or vehicle for 5 weeks. In addition, cultured neonatal rat ventricular cardiomyocytes and fibroblasts were exposed to angiotensin II in the presence or absence of lansoprazole. At 5 weeks after TAC, the heart weight/body weight ratio was lower in lansoprazole-treated mice than in untreated mice, as was the lung weight/body weight ratio, while left ventricular (LV) fractional shortening and the maximum and minimum rates of change of the LV pressure were higher in lansoprazole-treated mice, along with less cardiac fibrosis. In cultured cardiomyocytes, lansoprazole inhibited angiotensin II-induced protein synthesis and hypertrophy, as well as inhibiting proliferation of fibroblasts. Lansoprazole decreased myocardial levels of phosphorylated Akt, phosphorylated glycogen synthase kinase 3β, and active β-catenin in TAC mice and in angiotensin II-stimulated cardiomyocytes. After overexpression of active β-catenin or knockdown of H+/K+-ATPase α-subunit, lansoprazole still significantly attenuated myocyte hypertrophy. Conclusion Lansoprazole inhibits cardiac remodelling by suppressing activation of the Akt/GSK3β/β-catenin pathway independent of H+/K+-ATPase inhibition, and these findings may provide a novel insight into the pharmacological effects of PPIs with regard to alleviation of cardiac remodelling.


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