Nitric Oxide-cGMP-PKG Pathway Acts on Orai1 to Inhibit the Hypertrophy of Human Embryonic Stem Cell-Derived Cardiomyocytes.
Cardiac hypertrophy is an abnormal enlargement of heart muscle. It frequently results in congestive heart failure, which is a leading cause of human death. Previous studies demonstrated that the nitric oxide (NO), cyclic GMP (cGMP), and protein kinase G (PKG) signaling pathway can inhibit cardiac hypertrophy and thus improve cardiac function. However, the underlying mechanisms are not fully understood. Here, based on the human embryonic stem cell-derived cardiomyocyte (hESC-CM) model system, we showed that Orai1, the pore-forming subunit of store-operated Ca(2+) entry (SOCE), is the downstream effector of PKG. Treatment of hESC-CMs with an α-adrenoceptor agonist phenylephrine (PE) caused a marked hypertrophy, which was accompanied by an upregulation of Orai1. Moreover, suppression of Orai1 expression/activity using Orai1-siRNAs or a dominant-negative construct Orai1(G98A) inhibited the hypertrophy, suggesting that Orai1-mediated SOCE is indispensable for the PE-induced hypertrophy of hESC-CMs. In addition, the hypertrophy was inhibited by NO and cGMP via activating PKG. Importantly, substitution of Ala for Ser(34) in Orai1 abolished the antihypertrophic effects of NO, cGMP, and PKG. Furthermore, PKG could directly phosphorylate Orai1 at Ser(34) and thus prevent Orai1-mediated SOCE. Together, we conclude that NO, cGMP, and PKG inhibit the hypertrophy of hESC-CMs via PKG-mediated phosphorylation on Orai1-Ser-34. These results provide novel mechanistic insights into the action of cGMP-PKG-related antihypertrophic agents, such as NO donors and sildenafil.
Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.|Department of Hematology, The 3rd Xiangya Hospital, Central South University, Changsha, People's Republic of China.
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Wang
Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.
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Li
Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.
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Zhang
Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China.|The Department of Physiology, The University of Hong Kong, Hong Kong, People's Republic of China.
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Poon
Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China.
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Kong
Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China.|The Department of Physiology, The University of Hong Kong, Hong Kong, People's Republic of China.
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Boheler
Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.
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Huang
Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China.
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Li
Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.
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Yao
D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics*; D006332:Cardiomegaly / Q000235:genetics* / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics; D006152:Cyclic GMP / Q000008:administration & dosage / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006333:Heart Failure / Q000235:genetics* / Q000473:pathology; D000066449:Human Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000008:administration & dosage / Q000378:metabolism; D000071740:ORAI1 Protein; D010656:Phenylephrine / Q000008:administration & dosage; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
D015220:Calcium Channels; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D010656:Phenylephrine; D009569:Nitric Oxide; D017869:Cyclic GMP-Dependent Protein Kinases; D006152:Cyclic GMP; D002118:Calcium
Ca2+; Cardiomyocytes; Human embryonic stem cells; Hypertrophy; Orai1