scholarly journals Lysosomal-Associated Protein Transmembrane 5 Functions as a Novel Negative Regulator of Pathological Cardiac Hypertrophy

2021 ◽  
Vol 8 ◽  
Author(s):  
Lu Gao ◽  
Sen Guo ◽  
Rui Long ◽  
Lili Xiao ◽  
Rui Yao ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Ventricular Myocytes ◽  
Therapeutic Potential ◽  
Negative Regulator ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Pathological Cardiac Hypertrophy

Lysosomal-associated protein transmembrane 5 (LAPTM5) is mainly expressed in immune cells and has been reported to regulate inflammation, apoptosis and autophagy. Although LAPTM5 is expressed in the heart, whether LAPTM5 plays a role in regulating cardiac function remains unknown. Here, we show that the expression of LAPTM5 is dramatically decreased in murine hypertrophic hearts and isolated hypertrophic cardiomyocytes. In this study, we investigated the role of LAPTM5 in pathological cardiac hypertrophy and its possible mechanism. Our results show that LAPTM5 gene deletion significantly exacerbates cardiac remodeling, which can be demonstrated by reduced myocardial hypertrophy, fibrosis, ventricular dilation and preserved ejection function, whereas the opposite phenotype was observed in LAPTM5 overexpression mice. In line with the in vivo results, knockdown of LAPTM5 exaggerated angiotensin II-induced cardiomyocyte hypertrophy in neonatal rat ventricular myocytes, whereas overexpression of LAPTM5 protected against angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, LAPTM5 directly bound to Rac1 and further inhibited MEK-ERK1/2 signaling, which ultimately regulated the development of cardiac hypertrophy. In addition, the antihypertrophic effect of LAPTM5 was largely blocked by constitutively active mutant Rac1 (G12V). In conclusion, our results suggest that LAPTM5 is involved in pathological cardiac hypertrophy and that targeting LAPTM5 has great therapeutic potential in the treatment of pathological cardiac hypertrophy.

scholarly journals LCZ696 Ameliorates Oxidative Stress and Pressure Overload-Induced Pathological Cardiac Remodeling by Regulating the Sirt3/MnSOD Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shi Peng ◽  
Xiao-feng Lu ◽  
Yi-ding Qi ◽  
Jing Li ◽  
Juan Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Pressure Overload ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Rat Cardiomyocytes ◽  
Pathological Cardiac Hypertrophy

Aims. We aimed to investigate whether LCZ696 protects against pathological cardiac hypertrophy by regulating the Sirt3/MnSOD pathway. Methods. In vivo, we established a transverse aortic constriction animal model to establish pressure overload-induced heart failure. Subsequently, the mice were given LCZ696 by oral gavage for 4 weeks. After that, the mice underwent transthoracic echocardiography before they were sacrificed. In vitro, we introduced phenylephrine to prime neonatal rat cardiomyocytes and small-interfering RNA to knock down Sirt3 expression. Results. Pathological hypertrophic stimuli caused cardiac hypertrophy and fibrosis and reduced the expression levels of Sirt3 and MnSOD. LCZ696 alleviated the accumulation of oxidative reactive oxygen species (ROS) and cardiomyocyte apoptosis. Furthermore, Sirt3 deficiency abolished the protective effect of LCZ696 on cardiomyocyte hypertrophy, indicating that LCZ696 induced the upregulation of MnSOD and phosphorylation of AMPK through a Sirt3-dependent pathway. Conclusions. LCZ696 may mitigate myocardium oxidative stress and apoptosis in pressure overload-induced heart failure by regulating the Sirt3/MnSOD pathway.

scholarly journals Myricetin Alleviates Pathological Cardiac Hypertrophy via TRAF6/TAK1/MAPK and Nrf2 Signaling Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Hai-han Liao ◽  
Nan Zhang ◽  
Yan-yan Meng ◽  
Hong Feng ◽  
Jing-jing Yang ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Pressure Overload ◽  
Mapk Signaling ◽  
Neonatal Rat ◽  
Mouse Heart ◽  
Pathological Cardiac Hypertrophy ◽  
Pathological Hypertrophy ◽  
Nrf2 Signaling Pathway

Myricetin (Myr) is a common plant-derived polyphenol and is well recognized for its multiple activities including antioxidant, anti-inflammation, anticancer, and antidiabetes. Our previous studies indicated that Myr protected mouse heart from lipopolysaccharide and streptozocin-induced injuries. However, it remained to be unclear whether Myr could prevent mouse heart from pressure overload-induced pathological hypertrophy. Wild type (WT) and cardiac Nrf2 knockdown (Nrf2-KD) mice were subjected to aortic banding (AB) surgery and then administered with Myr (200 mg/kg/d) for 6 weeks. Myr significantly alleviated AB-induced cardiac hypertrophy, fibrosis, and cardiac dysfunction in both WT and Nrf2-KD mice. Myr also inhibited phenylephrine- (PE-) induced neonatal rat cardiomyocyte (NRCM) hypertrophy and hypertrophic markers’ expression in vitro. Mechanically, Myr markedly increased Nrf2 activity, decreased NF-κB activity, and inhibited TAK1/p38/JNK1/2 MAPK signaling in WT mouse hearts. We further demonstrated that Myr could inhibit TAK1/p38/JNK1/2 signaling via inhibiting Traf6 ubiquitination and its interaction with TAK1 after Nrf2 knockdown in NRCM. These results strongly suggested that Myr could attenuate pressure overload-induced pathological hypertrophy in vivo and PE-induced NRCM hypertrophy via enhancing Nrf2 activity and inhibiting TAK1/P38/JNK1/2 phosphorylation by regulating Traf6 ubiquitination. Thus, Myr might be a potential strategy for therapy or adjuvant therapy for malignant cardiac hypertrophy.

Abstract 470: Raf Kinase Inhibitors Activate ERK1/2 in Cardiomyocytes, Promoting Cardiac Hypertrophy in vitro and, in the Context of Angiotensin II-Induced Hypertension in Mice, in vivo

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Daniel N Meijles ◽  
Michelle A Hardyman ◽  
Stephen J Fuller ◽  
Kerry A Rostron ◽  
Sam J Leonard ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Kinase Inhibitors ◽  
Left Ventricular ◽  
Neonatal Rat ◽  
Internal Diameter ◽  
Dividing Cells ◽  
Lv Volume

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.

Abstract 1828: Dyxin/Lmcd1 Mediates Cardiac Hypertrophy Both In Vitro And In Vivo

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Derk Frank ◽  
Robert Frauen ◽  
Christiane Hanselmann ◽  
Christian Kuhn ◽  
Rainer Will ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cardiac Hypertrophy ◽  
Neonatal Rat ◽  
Heart Weight ◽  
Cardiomyocyte Hypertrophy ◽  
The Novel ◽  
Rat Cardiomyocytes ◽  
A Genome

In order to identify new molecular mediators of cardiomyocyte hypertrophy, we performed a genome wide mRNA microarray screen of biomechanically stretched neonatal rat cardiomyocytes (NRCM). We found the novel sarcomeric LIM protein Dyxin/Lmcd1 being significantly upregulated (5.6x, p<0.001). Moreover, Dyxin was also significantly induced in several mouse models of myocardial hypertrophy including aortic banding, calcineurin overexpression and angiotensin stimulation, suggesting a potential role as a mediator of cardiac hypertrophy. To further test this hypothesis, we adenovirally overexpressed Dyxin in NRCM which potently induced cellular hypertrophy (150%, p<0.001) and the hypertrophic gene program (ANF, BNP). Consistent with an induction of calcineurin signalling, the calcineurin-responsive gene Rcan1– 4 (MCIP1.4) was found significantly upregulated (3.2x, p<0.001). Conversely, knockdown of Dyxin (−75% on protein level) via miRNA completely blunted the hypertrophic response to hypertrophic stimuli, including stretch and PE (both p<0.001). Furthermore, PE-mediated activation of calcineurin signaling (Upregulation of Rcan1– 4 by 7.3x, p<0.001) was completely blocked by knockdown of Dyxin. To confirm these results in vivo, we next generated transgenic mice with cardiac-restricted overexpression of Dyxin using the α -MHC promoter. Despite normal cardiac function as assessed by echocardiography, adult transgenic mice displayed significant cardiac hypertrophy in morphometrical analyses (3.9 vs. 3.5 mg/g LV/heart weight, n=8–11, p<0.05). This finding was supplemented by a robust induction of the hypertrophic gene program including ANF (3.7-fold, n=6, p=0.01) and α -skeletal actin (2.8-fold, n=6, p<0.05). Likewise, Rcan1– 4 was found upregulated (+112%, n=5, p<0.05), Taken together, we show that the novel sarcomeric z-disc protein Dyxin/Lmcd1 is significantly upregulated in several models of cardiac hypertrophy and potently induces cardiomyocyte hypertrophy both in vitro and in vivo. Mechanistically, Lmcd1/Dyxin appears to signal through the calcineurin pathway.

scholarly journals (–)-Epicatechin Suppresses Angiotensin II-induced Cardiac Hypertrophy via the Activation of the SP1/SIRT1 Signaling Pathway

2017 ◽  
Vol 41 (5) ◽  
pp. 2004-2015 ◽  
Author(s):  
Zeng-xiang Dong ◽  
Lin Wan ◽  
Ren-jun Wang ◽  
Yuan-qi Shi ◽  
Guang-zhong Liu ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Signaling Pathway ◽  
Cardiomyocyte Hypertrophy ◽  
Ang Ii ◽  
Beneficial Effects ◽  
Protein Levels ◽  
Qrt Pcr

Background/Aims: Flavonol (–)-epicatechin (EPI) is present in high amounts in cocoa and tea products, and has been shown to exert beneficial effects on the cardiovascular system. However, the precise mechanism of EPI on cardiomyocyte hypertrophy has not yet been determined. In this study, we examined whether EPI could inhibit cardiac hypertrophy. Methods: We utilised cultured neonatal mouse cardiomyocytes and mice for immunofluorescence, immunochemistry, qRT-PCR, and western blot analyses. Results: 1µM EPI significantly inhibited 1µM angiotensin II (Ang II)-induced increase of cardiomyocyte size, as well as the mRNA and protein levels of ANP, BNP and β-MHC in vitro. The effects of EPI were accompanied with an up-regulation of SP1 and SIRT1, and were abolished by SP1 inhibition. Up-regulation of SP1 could block Ang II-induced increase in cardiomyocyte size, as well as the mRNA and protein levels of ANP, BNP and β-MHC, and increase the protein levels of SIRT1 in vitro. Moreover, 1 mg/kg body weight/day EPI significantly inhibited mouse cardiac hypertrophy induced by Ang II, which could be eliminated by SP1 inhibition in vivo. Conclusion: Our data indicated that EPI inhibited AngII-induced cardiac hypertrophy by activating the SP1/SIRT1 signaling pathway.

scholarly journals Novel PGC-1α/ATF5 Axis Partly Activates UPRmt and Mediates Cardioprotective Role of Tetrahydrocurcumin in Pathological Cardiac Hypertrophy

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Bing Zhang ◽  
Yanzhen Tan ◽  
Zhengbin Zhang ◽  
Pan Feng ◽  
Wenyuan Ding ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cardiac Hypertrophy ◽  
Test Group ◽  
Neonatal Rat ◽  
Activation Mechanism ◽  
Cardiomyocyte Hypertrophy ◽  
Control Group ◽  
Pathological Cardiac Hypertrophy

Mitochondrial unfolding protein response (UPRmt) effectively resists the pathological cardiac hypertrophy and improves the mitochondrial function. However, the specific activation mechanism and drugs that can effectively activate UPRmt in the cardiac muscle are yet to be elucidated. The aim of this study was to determine the regulation role of UPRmt on preventing pathological cardiac hypertrophy by tetrahydrocurcumin (THC) and explore its underlying molecular mechanism. Male C57BL/6J wild-type (WT) mice were divided into a control group and subjected to sham treatment for 4 weeks, and a test group which was subjected to transverse aortic constriction (TAC) surgery. Animals in the control and test group were orally administered THC (50 mg/kg) for 4 weeks after TAC procedure; an equivalent amount of saline was orally administered in the control sham-treated group and the TAC group. Subsequently, oxidative stress and UPRmt markers were assessed in these mice, and cardiac hypertrophy, fibrosis, and cardiac function were tested. Small interfering RNA (siRNA) targeting proliferator-activated receptor-gamma coactivator (PGC)-1α and activating transcription factor 5 (ATF5) were used to determine the UPRmt activation mechanism. THC supplement partly upregulated UPRmt effectors and inhibited TAC-induced oxidative stress compared with TAC-operated WT mice, thereby substantially attenuating contractile dysfunction, cardiac hypertrophy, and fibrosis. Furthermore, PGC-1α knockdown blunted the UPRmt activation and the cardioprotective role of THC. The interaction between PGC-1α and ATF5 was tested in neonatal rat cardiac myocytes under normal conditions. The results showed that PGC-1α was an upstream effector of ATF5 and partly activated UPRmt. In vitro, phenylephrine- (PE-) induced cardiomyocyte hypertrophy caused ATF5 upregulating rather than downregulating corresponding to the downregulation of PGC-1α. The PGC-1α/ATF5 axis mediated the UPRmt activation and stress-resistance role of THC in vitro. Collectively, the present study provides the first evidence that PGC-1 and ATF5 can form a signaling axis to partly activate UPRmt that mediates the cardioprotective role of THC in pathological cardiac hypertrophy.

scholarly journals SIRT1 Functions as an Important Regulator of Estrogen-Mediated Cardiomyocyte Protection in Angiotensin II-Induced Heart Hypertrophy

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Tao Shen ◽  
Ling Ding ◽  
Yang Ruan ◽  
Weiwei Qin ◽  
Yajun Lin ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Sirtuin 1 ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Mouse Heart ◽  
Heart Hypertrophy ◽  
Sirt1 Expression ◽  
Important Regulator

Background. Sirtuin 1 (SIRT1) is a member of the sirtuin family, which could activate cell survival machinery and has been shown to be protective in regulation of heart function. Here, we determined the mechanism by which SIRT1 regulates Angiotensin II- (AngII-) induced cardiac hypertrophy and injury in vivo and in vitro.Methods. We analyzed SIRT1 expression in the hearts of control and AngII-induced mouse hypertrophy. Female C57BL/6 mice were ovariectomized and pretreated with 17β-estradiol to measure SIRT1 expression. Protein synthesis, cardiomyocyte surface area analysis, qRT-PCR, TUNEL staining, and Western blot were performed on AngII-induced mouse heart hypertrophy samples and cultured neonatal rat ventricular myocytes (NRVMs) to investigate the function of SIRT1.Results. SIRT1 expression was slightly upregulated in AngII-induced mouse heart hypertrophy in vivo and in vitro, accompanied by elevated cardiomyocyte apoptosis. SIRT1 overexpression relieves AngII-induced cardiomyocyte hypertrophy and apoptosis. 17β-Estradiol was able to protect cardiomyocytes from AngII-induced injury with a profound upregulation of SIRT1 and activation of AMPK. Moreover, estrogen receptor inhibitor ICI 182,780 and SIRT1 inhibitor niacinamide could block SIRT1’s protective effect.Conclusions. These results indicate that SIRT1 functions as an important regulator of estrogen-mediated cardiomyocyte protection during AngII-induced heart hypertrophy and injury.

scholarly journals Kaempferol Alleviates Angiotensin II-Induced Cardiac Dysfunction and Interstitial Fibrosis in Mice

2017 ◽  
Vol 43 (6) ◽  
pp. 2253-2263 ◽  
Author(s):  
Yuan Liu ◽  
Lu Gao ◽  
Sen Guo ◽  
Yuzhou Liu ◽  
Xiaoyan Zhao ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Cardiac Dysfunction ◽  
Cardiac Fibrosis ◽  
Neonatal Rat ◽  
Cardiac Remodelling ◽  
Ang Ii ◽  
Ventricular Fibrosis

Background/Aims: Endothelial-to-mesenchymal transition (EndMT) is a mechanism that promotes cardiac fibrosis induced by Angiotensin II (AngII). Kaempferol (KAE) is a monomer component mainly derived from the rhizome of Kaempferia galanga L. It shows anti-inflammatory, anti-oxidative, anti-microbial and anti-cancer properties, which can be used in the treatment of cancer, cardiovascular diseases, infection, etc. But, its effects on the development of cardiac remodelling remain completely unknown. The aim of the present study was to determine whether KAE attenuates cardiac hypertrophy induced by angiotensin II (Ang II) in cultured neonatal rat cardiac myocytes in vitro and cardiac hypertrophy induced by AngII infusion in mice in vivo. Methods: Male wild-type mice aged 8-10 weeks with or without KAE were subjected to AngII or saline, to induce fibrosis or as a control, respectively. Morphological changes, echocardiographic parameters, histological analyses, and hypertrophic markers were also used to evaluate hypertrophy. Results: KAE prevented and reversed cardiac remodelling induced by AngII. The KAE in this model exerted no basal effects but attenuated cardiac fibrosis, hypertrophy and dysfunction induced by AngII. Both in vivo and in vitro experiments demonstrated that Ang II infusion or TGF-β induced EndMT can be reduced by KAE and the proliferation and activation of cardiac fibroblasts (CFs) can be inhibited by KAE. Conclusions: The results suggest that KAE prevents and reverses ventricular fibrosis and cardiac dysfunction, providing an experimental basis for clinical treatment on ventricular fibrosis.

Abstract 157: Alterations in Signaling Pathways During Regression of Pathological Cardiac Hypertrophy

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Deanna Langager ◽  
Leslie Leinwand
Keyword(s):  
Cardiac Hypertrophy ◽  
Signaling Pathways ◽  
Ventricular Myocytes ◽  
Left Ventricular ◽  
Neonatal Rat ◽  
Akt Pathway ◽  
Compensatory Mechanism ◽  
Akt Inhibitor ◽  
Pathological Cardiac Hypertrophy

Introduction: Cardiac hypertrophy is initially, a compensatory mechanism to maintain cardiac output when there is an increased load on the heart. However, if cardiac hypertrophy persists for an extended time, there can be maladaptive changes to the myocardium. Even when the underlying cause of hypertrophy is treated, regression is often minimal or absent. Clinical cases of cardiac regression do exist, including patients receiving bariatric surgery or a left ventricular assist device. While many of the mechanisms leading to cardiac hypertrophy are well understood, little is known about the mechanisms of reversal of hypertrophy and why it is sometimes irreversible. We hypothesized that a reversal of isoproterenol (Iso) induced cardiac hypertrophy in the mouse will be observed within 7 days following the removal of the stimulus and we will be able to identify alterations in signaling pathways. Methods: We induced pathological cardiac hypertrophy with Iso for 7 days, at which peak hypertrophy is achieved. To identify if/when regression occurs, the Iso treatment was stopped and the mice were monitored for 7 days. Heart weights were measured at peak hypertrophy, post-drug days 1, 2, 3 & 7, along with vehicle treated mice (8/group). We used left ventricle tissue for protein analysis and protein degradation activity assays. Results: Regression from cardiac hypertrophy occurs by post-drug day 7 (p=0.016) in the Iso mouse model. p-Akt is increased with Iso treatment and returns to vehicle control levels by post-drug day 7. There is a decrease in p-mTOR and an increase in LC3-II levels at post-drug day 7, indicating a possible role of autophagy in cardiac regression. In addition, there was a decrease in cell size when neonatal rat ventricular myocytes were treated with the Akt inhibitor, Wortmannin, following phenylephrine induced hypertrophy. Conclusion: Regression of Iso-induced cardiac hypertrophy occurs in the mouse after 7 days following the removal of the stimulus. The Akt pathway is activated with Iso treatment and when this pathway is inactivated during regression, autophagy is activated, which may be an important mechanism to degrade proteins and lead to a decrease in cardiac hypertrophy. Finally, when the Akt pathway is inhibited in vitro , hypertrophic cells regress.

scholarly journals Ang II Promotes Cardiac Autophagy and Hypertrophy via Orai1/STIM1

2021 ◽  
Vol 12 ◽  
Author(s):  
Chang-Bo Zheng ◽  
Wen-Cong Gao ◽  
Mingxu Xie ◽  
Zhichao Li ◽  
Xin Ma ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Neonatal Rat ◽  
Ang Ii ◽  
Contributing Factors ◽  
Rat Cardiomyocytes ◽  
Pathological Cardiac Hypertrophy ◽  
Causative Factors ◽  
Cardiomyocyte Autophagy

The pathophysiology of cardiac hypertrophy is complex and multifactorial. Both the store-operated Ca2+ entry (SOCE) and excessive autophagy are the major causative factors for pathological cardiac hypertrophy. However, it is unclear whether these two causative factors are interdependent. In this study, we examined the functional role of SOCE and Orai1 in angiotensin II (Ang II)-induced autophagy and hypertrophy using in vitro neonatal rat cardiomyocytes (NRCMs) and in vivo mouse model, respectively. We show that YM-58483 or SKF-96365 mediated pharmacological inhibition of SOCE, or silencing of Orai1 with Orail-siRNA inhibited Ang II-induced cardiomyocyte autophagy both in vitro and in vivo. Also, the knockdown of Orai1 attenuated Ang II-induced pathological cardiac hypertrophy. Together, these data suggest that Ang II promotes excessive cardiomyocyte autophagy through SOCE/Orai1 which can be the prime contributing factors in cardiac hypertrophy.

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