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Zheng L, Spagnol G, Gandhi DR, Sharma K, Kumar V, Patel KP, Sorgen PL. Inhibition of Pyk2 Improves Cx43 Intercalated Disc Localization, Infarct Size, and Cardiac Function in Rats With Heart Failure. Circ Heart Fail 2023; 16:e010294. [PMID: 37465947 PMCID: PMC10524803 DOI: 10.1161/circheartfailure.122.010294] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 05/12/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND Heart failure causes changes in Cx43 (Connexin43) regulation that are associated with arrhythmic heart disease. Pyk2 (proline-rich tyrosine kinase 2) is activated in cardiomyopathies and phosphorylates Cx43 to decrease intercellular communication. This study was designed to determine if Pyk2 inhibition improves cardiac function in a myocardial infarction (MI)-induced heart failure model in rats. METHODS MI (ligation of left anterior descending artery) rats were treated with the Pyk2 inhibitor PF4618433. Hemodynamic and structural parameters were monitored in Sham (n=5), MI-vehicle (n=5), and MI-PF4618433 (n=8) groups. Heart tissues were collected after 6 weeks to assess Pyk2 and Cx43 protein level and localization. RESULTS PF4618433 produced no observed adverse effects and inhibited ventricular Pyk2. PF4618433 reduced the MI infarct size from 34% to 17% (P=0.007). PF4618433 improved stroke volume (P=0.031) and cardiac output (P=0.009) in comparison to MI-vehicle with values similar to the Sham group. PF4618433 also led to an increase in the ejection fraction (P=0.002) and fractional shortening (P=0.006) when compared with the MI-vehicle (32% and 35% improvement, respectively) yet were lower in comparison with the Sham group. Pyk2 inhibition decreased Cx43 tyrosine phosphorylation (P=0.043) and maintained Cx43 at the intercalated disc in the distal ventricle 6 weeks post-MI. CONCLUSIONS Unlike other attempts to decrease Cx43 remodeling after MI-induced heart failure, inhibition of Pyk2 activity maintained Cx43 at the intercalated disc. This may have aided in the reduced infarct size (acute time frame) and improved cardiac function (chronic time frame). Additionally, we provide evidence that Pyk2 is activated following MI in human left ventricle, implicating a novel potential target for therapy in patients with heart failure.
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Affiliation(s)
- Li Zheng
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Devashri R. Gandhi
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kanika Sharma
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Vikas Kumar
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kaushik P. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Paul L. Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Fibroblast growth factor 18 alleviates stress-induced pathological cardiac hypertrophy in male mice. Nat Commun 2023; 14:1235. [PMID: 36871047 PMCID: PMC9985628 DOI: 10.1038/s41467-023-36895-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 02/22/2023] [Indexed: 03/06/2023] Open
Abstract
Fibroblast growth factor-18 (FGF18) has diverse organ development and damage repair roles. However, its role in cardiac homeostasis following hypertrophic stimulation remains unknown. Here we investigate the regulation and function of the FGF18 in pressure overload (PO)-induced pathological cardiac hypertrophy. FGF18 heterozygous (Fgf18+/-) and inducible cardiomyocyte-specific FGF18 knockout (Fgf18-CKO) male mice exposed to transverse aortic constriction (TAC) demonstrate exacerbated pathological cardiac hypertrophy with increased oxidative stress, cardiomyocyte death, fibrosis, and dysfunction. In contrast, cardiac-specific overexpression of FGF18 alleviates hypertrophy, decreased oxidative stress, attenuates cardiomyocyte apoptosis, and ameliorates fibrosis and cardiac function. Tyrosine-protein kinase FYN (FYN), the downstream factor of FGF18, was identified by bioinformatics analysis, LC-MS/MS and experiment validation. Mechanistic studies indicate that FGF18/FGFR3 promote FYN activity and expression and negatively regulate NADPH oxidase 4 (NOX4), thereby inhibiting reactive oxygen species (ROS) generation and alleviating pathological cardiac hypertrophy. This study uncovered the previously unknown cardioprotective effect of FGF18 mediated by the maintenance of redox homeostasis through the FYN/NOX4 signaling axis in male mice, suggesting a promising therapeutic target for the treatment of cardiac hypertrophy.
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Mohamed RMSM, Ahmad EA, Omran BHF, Sakr AT, Ibrahim IAAEH, Mahmoud MF, El-Naggar ME. Carvedilol ameliorates dexamethasone-induced myocardial injury in rats independent of its action on the α1-adrenergic receptor. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022; 395:1537-1548. [PMID: 36085425 PMCID: PMC9630193 DOI: 10.1007/s00210-022-02285-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/24/2022] [Indexed: 11/28/2022]
Abstract
The current study aimed to investigate the cardiotoxic effect of dexamethasone-high-dose in rats, the therapeutic effect of carvedilol and the role of α1-adrenergic receptor (α1AR). The experiment involved 6 groups: control, dexamethasone (10 mg/kg), carvedilol (10 mg/kg), phenylephrine (1 mg/kg), phenylephrine plus carvedilol and propranolol (30 mg/kg). Drugs and vehicles were given for 7 days. Dexamethasone was given with the drugs in the last 4 groups. On the 8th-day and after overnight fasting, serum and cardiac samples were collected. Serum levels of cardiac troponin I and creatine kinase-myoglobin as well as cardiac levels of diacylglycerol, malondialdehyde, kinase activity of Akt, transforming growth factor-β, Smad3 and alpha smooth muscle actin were measured. Cardiac samples were also used for histopathological examination using hematoxylin-eosin and Sirius red stains, in addition to immunohistochemical examination using β-arrestin2 antibody. Dexamethasone induced cardiac injury via increasing oxidative stress, apoptosis and profibrotic signals. Carvedilol significantly reduced the dexamethasone-induced cardiotoxicity. Using phenylephrine, a competitive α1-agonist, with carvedilol potentiated the cardioprotective actions of carvedilol. Propranolol, a β-blocker without activity on α1ARs, showed higher cardiac protection than carvedilol. Dexamethasone-high-dose upregulates cardiac oxidative stress, apoptotic and profibrotic signals and induces cardiac injury. Blocking the α1-adrenergic receptor by carvedilol attenuates its cardioprotective effects against dexamethasone-induced cardiotoxicity.
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Affiliation(s)
- Rasha M S M Mohamed
- Department of Clinical Pharmacology, Faculty of Medicine, Zagazig University, Zagazig, 44519, Egypt
| | - Enssaf Ahmad Ahmad
- Department of Human Anatomy and Embryology, Faculty of Medicine, Zagazig University, Zagazig, 44519, Egypt
| | - Bothina H F Omran
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Zagazig University, Zagazig, 44519, Egypt
| | - Amr T Sakr
- Department of Biochemistry, Faculty of Pharmacy, University of Sadat City, Menoufia, 32897, Egypt
| | - Islam A A E-H Ibrahim
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt.
| | - Mona F Mahmoud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt
| | - Mostafa E El-Naggar
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Sadat City, Menoufia, 32897, Egypt
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Zheng L, Trease AJ, Katsurada K, Spagnol G, Li H, Shi W, Duan B, Patel KP, Sorgen PL. Inhibition of Pyk2 and Src activity improves Cx43 gap junction intercellular communication. J Mol Cell Cardiol 2020; 149:27-40. [PMID: 32956670 DOI: 10.1016/j.yjmcc.2020.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 11/24/2022]
Abstract
Identification of proteins that interact with Cx43 has been instrumental in the understanding of gap junction (GJ) regulation. An in vitro phosphorylation screen identified that Protein tyrosine kinase 2 beta (Pyk2) phosphorylated purified Cx43CT and this led us to characterize the impact of this phosphorylation on Cx43 function. Mass spectrometry identified Pyk2 phosphorylates Cx43 residues Y247, Y265, Y267, and Y313. Western blot and immunofluorescence staining using HeLaCx43 cells, HEK 293 T cells, and neonatal rat ventricular myocytes (NRVMs) revealed Pyk2 can be activated by Src and active Pyk2 interacts with Cx43 at the plasma membrane. Overexpression of Pyk2 increases Cx43 phosphorylation and knock-down of Pyk2 decreases Cx43 phosphorylation, without affecting the level of active Src. In HeLaCx43 cells treated with PMA to activate Pyk2, a decrease in Cx43 GJ intercellular communication (GJIC) was observed when assayed by dye transfer. Moreover, PMA activation of Pyk2 could be inhibited by the small molecule PF4618433. This partially restored GJIC, and when paired with a Src inhibitor, returned GJIC to the no PMA control-level. The ability of Pyk2 and Src inhibitors to restore Cx43 function in the presence of PMA was also observed in NRVMs. Additionally, an animal model of myocardial infarction induced heart failure showed a higher level of active Pyk2 activity and increased interaction with Cx43 in ventricular myocytes. Src inhibitors have been used to reverse Cx43 remodeling and improve heart function after myocardial infarction; however, they alone could not fully restore proper Cx43 function. Our data suggest that Pyk2 may need to be inhibited, in addition to Src, to further (if not completely) reverse Cx43 remodeling and improve intercellular communication.
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Affiliation(s)
- Li Zheng
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Andrew J Trease
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kenichi Katsurada
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Hanjun Li
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Wen Shi
- Division of Cardiology, Department of Internal Medicine/Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Bin Duan
- Division of Cardiology, Department of Internal Medicine/Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kaushik P Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Paul L Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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Liu S, Chen L, Xu Y. Significance of PYK2 level as a prognosis predictor in patients with colon adenocarcinoma after surgical resection. Onco Targets Ther 2018; 11:7625-7634. [PMID: 30464511 PMCID: PMC6217216 DOI: 10.2147/ott.s169531] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Proline-rich/Ca2+-activated tyrosine kinase 2 (PYK2) belongs to the non-receptor tyrosine kinase family, regulates downstream signaling via catalyzing protein phosphorylation. We aimed to investigate clinical significance and mechanisms of PYK2 in colon adenocarcinoma (CAC). Methods Real time quantitative PCR and immunohistochemistry staining was used to evaluate the expression of PYK2 in clinical CAC tissues. Its association with clinicopathologic characteristics was analyzed by Chi-square test. Kaplan-Meier univariate survival analysis and multivariate Cox regression analysis were used to identify clinical significance of PYK2 in the overall survival of CAC patients. Transfection of PYK2 were conducted to reveal the underlying mechanism in regulating CAC progression. Results We found that PYK2 was upregulated in CAC tissues compared with normal colon tissues on both RNA and protein levels. Higher tissue PYK2 expression level was closely associated with lymph node metastasis. Statistical analyses indicated PYK2 as an independent prognostic biomarker for CAC. Cellular studies demonstrated that PYK2 enhanced the capacities of tumor proliferation and invasion. Moreover, the phosphorylation level of AKT was positively correlated with PYK2 expression, subsequently modulate expression of c-Myc and Cyclin D1, suggesting that PYK2 may promote tumor progression through activating AKT signaling. Conclusion High PYK2 in CAC tissues indicate poor prognosis.
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Affiliation(s)
- Shufang Liu
- Department of Laboratory Medicine, Linyi Central Hospital, Linyi, Shandong 276400, China
| | - Lingling Chen
- Department of Laboratory Medicine, Linyi Central Hospital, Linyi, Shandong 276400, China
| | - Yunfei Xu
- Department of General Surgery, Qilu Hospital Affiliated to Shandong University, Jinan, Shandong 250012, China,
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Zhai M, Liu Z, Zhang B, Jing L, Li B, Li K, Chen X, Zhang M, Yu B, Ren K, Yang Y, Yi W, Yang J, Liu J, Yi D, Liang H, Jin Z, Reiter RJ, Duan W, Yu S. Melatonin protects against the pathological cardiac hypertrophy induced by transverse aortic constriction through activating PGC-1β: In vivo and in vitro studies. J Pineal Res 2017; 63. [PMID: 28708271 DOI: 10.1111/jpi.12433] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/10/2017] [Indexed: 12/26/2022]
Abstract
Melatonin, a circadian molecule secreted by the pineal gland, confers a protective role against cardiac hypertrophy induced by hyperthyroidism, chronic hypoxia, and isoproterenol. However, its role against pressure overload-induced cardiac hypertrophy and the underlying mechanisms remains elusive. In this study, we investigated the pharmacological effects of melatonin on pathological cardiac hypertrophy induced by transverse aortic constriction (TAC). Male C57BL/6 mice underwent TAC or sham surgery at day 0 and were then treated with melatonin (20 mg/kg/day, via drinking water) for 4 or 8 weeks. The 8-week survival rate following TAC surgery was significantly increased by melatonin. Melatonin treatment for 8 weeks markedly ameliorated cardiac hypertrophy. Compared with the TAC group, melatonin treatment for both 4 and 8 weeks reduced pulmonary congestion, upregulated the expression level of α-myosin heavy chain, downregulated the expression level of β-myosin heavy chain and atrial natriuretic peptide, and attenuated the degree of cardiac fibrosis. In addition, melatonin treatment slowed the deterioration of cardiac contractile function caused by pressure overload. These effects of melatonin were accompanied by a significant upregulation in the expression of peroxisome proliferator-activated receptor-gamma co-activator-1 beta (PGC-1β) and the inhibition of oxidative stress. In vitro studies showed that melatonin also protects against angiotensin II-induced cardiomyocyte hypertrophy and oxidative stress, which were largely abolished by knocking down the expression of PGC-1β using small interfering RNA. In summary, our results demonstrate that melatonin protects against pathological cardiac hypertrophy induced by pressure overload through activating PGC-1β.
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Affiliation(s)
- Mengen Zhai
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Zhenhua Liu
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Bin Zhang
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Lin Jing
- Cell Engineering Research Center and Department of Cell Biology, State Key Laboratory of Cancer, Fourth Military Medical University, Xi'an, China
| | - Buying Li
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Kaifeng Li
- Institute of Material Medical, School of Pharmacy, Fourth Military Medical University, Xi'an, China
| | - Xiuju Chen
- The First Brigade of Student, Fourth Military Medical University, Xi'an, China
| | - Meng Zhang
- Institute of Material Medical, School of Pharmacy, Fourth Military Medical University, Xi'an, China
| | - Bo Yu
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Kai Ren
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yang Yang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Wei Yi
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jian Yang
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jincheng Liu
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Dinghua Yi
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Hongliang Liang
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Zhenxiao Jin
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Russel J Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX, USA
| | - Weixun Duan
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Shiqiang Yu
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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Vairamani K, Wang HS, Medvedovic M, Lorenz JN, Shull GE. RNA SEQ Analysis Indicates that the AE3 Cl -/HCO 3- Exchanger Contributes to Active Transport-Mediated CO 2 Disposal in Heart. Sci Rep 2017; 7:7264. [PMID: 28779178 PMCID: PMC5544674 DOI: 10.1038/s41598-017-07585-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/29/2017] [Indexed: 02/06/2023] Open
Abstract
Loss of the AE3 Cl−/HCO3− exchanger (Slc4a3) in mice causes an impaired cardiac force-frequency response and heart failure under some conditions but the mechanisms are not known. To better understand the functions of AE3, we performed RNA Seq analysis of AE3-null and wild-type mouse hearts and evaluated the data with respect to three hypotheses (CO2 disposal, facilitation of Na+-loading, and recovery from an alkaline load) that have been proposed for its physiological functions. Gene Ontology and PubMatrix analyses of differentially expressed genes revealed a hypoxia response and changes in vasodilation and angiogenesis genes that strongly support the CO2 disposal hypothesis. Differential expression of energy metabolism genes, which indicated increased glucose utilization and decreased fatty acid utilization, were consistent with adaptive responses to perturbations of O2/CO2 balance in AE3-null myocytes. Given that the myocardium is an obligate aerobic tissue and consumes large amounts of O2, the data suggest that loss of AE3, which has the potential to extrude CO2 in the form of HCO3−, impairs O2/CO2 balance in cardiac myocytes. These results support a model in which the AE3 Cl−/HCO3− exchanger, coupled with parallel Cl− and H+-extrusion mechanisms and extracellular carbonic anhydrase, is responsible for active transport-mediated disposal of CO2.
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Affiliation(s)
- Kanimozhi Vairamani
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Hong-Sheng Wang
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Mario Medvedovic
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - John N Lorenz
- Department of Cellular and Molecular Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA.
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O-Uchi J, Jhun BS, Xu S, Hurst S, Raffaello A, Liu X, Yi B, Zhang H, Gross P, Mishra J, Ainbinder A, Kettlewell S, Smith GL, Dirksen RT, Wang W, Rizzuto R, Sheu SS. Adrenergic signaling regulates mitochondrial Ca2+ uptake through Pyk2-dependent tyrosine phosphorylation of the mitochondrial Ca2+ uniporter. Antioxid Redox Signal 2014; 21:863-79. [PMID: 24800979 PMCID: PMC4116095 DOI: 10.1089/ars.2013.5394] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS Mitochondrial Ca2+ homeostasis is crucial for balancing cell survival and death. The recent discovery of the molecular identity of the mitochondrial Ca2+ uniporter pore (MCU) opens new possibilities for applying genetic approaches to study mitochondrial Ca2+ regulation in various cell types, including cardiac myocytes. Basal tyrosine phosphorylation of MCU was reported from mass spectroscopy of human and mouse tissues, but the signaling pathways that regulate mitochondrial Ca2+ entry through posttranslational modifications of MCU are completely unknown. Therefore, we investigated α1-adrenergic-mediated signal transduction of MCU posttranslational modification and function in cardiac cells. RESULTS α1-adrenoceptor (α1-AR) signaling translocated activated proline-rich tyrosine kinase 2 (Pyk2) from the cytosol to mitochondrial matrix and accelerates mitochondrial Ca2+ uptake via Pyk2-dependent MCU phosphorylation and tetrametric MCU channel pore formation. Moreover, we found that α1-AR stimulation increases reactive oxygen species production at mitochondria, mitochondrial permeability transition pore activity, and initiates apoptotic signaling via Pyk2-dependent MCU activation and mitochondrial Ca2+ overload. INNOVATION Our data indicate that inhibition of α1-AR-Pyk2-MCU signaling represents a potential novel therapeutic target to limit or prevent mitochondrial Ca2+ overload, oxidative stress, mitochondrial injury, and myocardial death during pathophysiological conditions, where chronic adrenergic stimulation is present. CONCLUSION The α1-AR-Pyk2-dependent tyrosine phosphorylation of the MCU regulates mitochondrial Ca2+ entry and apoptosis in cardiac cells.
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Affiliation(s)
- Jin O-Uchi
- 1 Department of Medicine, Center for Translational Medicine, Jefferson Medical College, Thomas Jefferson University , Philadelphia, Pennsylvania
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Huang H, Joseph LC, Gurin MI, Thorp EB, Morrow JP. Extracellular signal-regulated kinase activation during cardiac hypertrophy reduces sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) transcription. J Mol Cell Cardiol 2014; 75:58-63. [PMID: 25008120 DOI: 10.1016/j.yjmcc.2014.06.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/23/2014] [Accepted: 06/26/2014] [Indexed: 10/25/2022]
Abstract
Pathologic cardiac hypertrophy can lead to heart failure, but the mechanisms involved are poorly understood. SERCA2 is critical for normal cardiac calcium handling and function and SERCA2 mRNA and protein levels are reduced by cardiac hypertrophy. We hypothesized that extracellular signal-regulated kinase (ERK) 1/2 activation during hypertrophy reduced SERCA2 transcription. Using a neonatal rat ventricular myocyte model of hypertrophy, we found that pharmacologic inhibitors of ERK activation preserve SERCA2 mRNA levels during hypertrophy. ERK activation is sufficient to reduce SERCA2 mRNA. We determined that ERK represses SERCA2 transcription via nuclear factor-kappaB (NFkB), and activation of NFkB is sufficient to reduce SERCA2 mRNA in cardiomyocytes. This work establishes novel connections between ERK, NFkB, and SERCA2 repression during cardiac hypertrophy. This mechanism may have implications for the progression of hypertrophy to heart failure.
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Affiliation(s)
- Haiyan Huang
- Department of Medicine, Division of Cardiology, College of Physicians and Surgeons of Columbia University, 622 W 168th Street, New York, NY 10032, United States
| | - Leroy C Joseph
- Department of Medicine, Division of Cardiology, College of Physicians and Surgeons of Columbia University, 622 W 168th Street, New York, NY 10032, United States
| | - Michael I Gurin
- Department of Medicine, Division of Cardiology, College of Physicians and Surgeons of Columbia University, 622 W 168th Street, New York, NY 10032, United States
| | - Edward B Thorp
- Department of Pathology and Feinberg Cardiovascular Research Institute, Northwestern University, Feinberg School of Medicine, 300 E. Superior Street, Chicago, IL 60611, United States
| | - John P Morrow
- Department of Medicine, Division of Cardiology, College of Physicians and Surgeons of Columbia University, 622 W 168th Street, New York, NY 10032, United States.
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10
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Koshman YE, Chu M, Kim T, Kalmanson O, Farjah M, Kumar M, Lewis W, Geenen DL, de Tombe P, Goldspink PH, Solaro RJ, Samarel AM. Cardiomyocyte-specific expression of CRNK, the C-terminal domain of PYK2, maintains ventricular function and slows ventricular remodeling in a mouse model of dilated cardiomyopathy. J Mol Cell Cardiol 2014; 72:281-91. [PMID: 24713463 PMCID: PMC4064715 DOI: 10.1016/j.yjmcc.2014.03.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 02/22/2014] [Accepted: 03/29/2014] [Indexed: 01/06/2023]
Abstract
Up-regulation and activation of PYK2, a member of the FAK family of protein tyrosine kinases, is involved in the pathogenesis of left ventricular (LV) remodeling and heart failure (HF). PYK2 activation can be prevented by CRNK, the C-terminal domain of PYK2. We previously demonstrated that adenoviral-mediated CRNK gene transfer improved survival and LV function, and slowed LV remodeling in a rat model of coronary artery ligation-induced HF. We now interrogate whether cardiomyocyte-specific, transgenic CRNK expression prevents LV remodeling and HF in a mouse model of dilated cardiomyopathy (DCM) caused by constitutively active Protein Kinase Cε (caPKCε). Transgenic (TG; FVB/N background) mice were engineered to express rat CRNK under control of the α-myosin heavy chain promoter, and crossed with FVB/N mice with cardiomyocyte-specific expression of caPKCε to create double TG mice. LV structure, function, and gene expression were evaluated in all 4 groups (nonTG FVB/N; caPKCε(+/-); CRNK(+/-); and caPKCε×CRNK (PXC) double TG mice) at 1, 3, 6, 9 and 12mo of age. CRNK expression followed a Mendelian distribution, and CRNK mice developed and survived normally through 12mo. Cardiac structure, function and selected gene expression of CRNK mice were similar to nonTG littermates. CRNK had no effect on caPKCε expression and vice versa. PYK2 was up-regulated ~6-fold in caPKCε mice, who developed a non-hypertrophic, progressive DCM with reduced systolic (Contractility Index=151±5 vs. 90±4s(-1)) and diastolic (Tau=7.5±0.5 vs. 14.7±1.3ms) function, and LV dilatation (LV Remodeling Index (LVRI)=4.2±0.1 vs. 6.0±0.3 for FVB/N vs. caPKCε mice, respectively; P<0.05 for each at 12mo). In double TG PXC mice, CRNK expression significantly prolonged survival, improved contractile function (Contractile Index=115±8s(-1); Tau=9.5±1.0ms), and reduced LV remodeling (LVRI=4.9±0.1). Cardiomyocyte-specific expression of CRNK improves contractile function and slows LV remodeling in a mouse model of DCM.
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Affiliation(s)
- Yevgeniya E Koshman
- Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Miensheng Chu
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Taehoon Kim
- Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Olivia Kalmanson
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Mariam Farjah
- Department of Physiology and Biophysics, University of Illinois - Chicago, Chicago, IL 60612, USA
| | - Mohit Kumar
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - William Lewis
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David L Geenen
- Department of Physiology and Biophysics, University of Illinois - Chicago, Chicago, IL 60612, USA
| | - Pieter de Tombe
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Paul H Goldspink
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - R John Solaro
- Department of Physiology and Biophysics, University of Illinois - Chicago, Chicago, IL 60612, USA
| | - Allen M Samarel
- Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA; Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA.
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11
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Abstract
Integrins are heterodimeric, transmembrane receptors that are expressed in all cells, including those in the heart. They participate in multiple critical cellular processes including adhesion, extracellular matrix organization, signaling, survival, and proliferation. Particularly relevant for a contracting muscle cell, integrins are mechanotransducers, translating mechanical to biochemical information. Although it is likely that cardiovascular clinicians and scientists have the highest recognition of integrins in the cardiovascular system from drugs used to inhibit platelet aggregation, the focus of this article will be on the role of integrins specifically in the cardiac myocyte. After a general introduction to integrin biology, the article will discuss important work on integrin signaling, mechanotransduction, and lessons learned about integrin function from a range of model organisms. Then we will detail work on integrin-related proteins in the myocyte, how integrins may interact with ion channels and mediate viral uptake into cells, and also play a role in stem cell biology. Finally, we will discuss directions for future study.
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Affiliation(s)
- Sharon Israeli-Rosenberg
- Department of Medicine, Cardiology, UCSD School of Medicine, La Jolla, CA, USA, and Veterans Administration San Diego Healthcare System, San Diego, CA, USA
| | - Ana Maria Manso
- Department of Medicine, Cardiology, UCSD School of Medicine, La Jolla, CA, USA, and Veterans Administration San Diego Healthcare System, San Diego, CA, USA
| | - Hideshi Okada
- Department of Medicine, Cardiology, UCSD School of Medicine, La Jolla, CA, USA, and Veterans Administration San Diego Healthcare System, San Diego, CA, USA
| | - Robert S Ross
- Department of Medicine, Cardiology, UCSD School of Medicine, La Jolla, CA, USA, and Veterans Administration San Diego Healthcare System, San Diego, CA, USA
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12
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Samarel AM. Focal adhesion signaling in heart failure. Pflugers Arch 2014; 466:1101-11. [PMID: 24515292 DOI: 10.1007/s00424-014-1456-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 11/28/2022]
Abstract
In this brief review, recent evidence is presented to indicate a role for specific components of the cardiomyocyte costamere (and its related structure the focal adhesion complex of cultured cardiomyocytes) in initiating and sustaining the aberrant signal transduction that contributes to myocardial remodeling and the progression to heart failure (HF). Special attention is devoted to the focal adhesion kinase family of nonreceptor protein tyrosine kinases in bidirectional signal transduction during cardiac remodeling and HF progression. Finally, some speculations and directions for future study are provided for this rapidly developing field of research.
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Affiliation(s)
- Allen M Samarel
- The Cardiovascular Institute and the Department of Medicine, Loyola University Chicago Stritch School of Medicine, Building 110, Rm 5222, 2160 South First Avenue, Maywood, IL, 60153, USA,
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13
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Abstract
Protein kinase C (PKC) isoforms have emerged as important regulators of cardiac contraction, hypertrophy, and signaling pathways that influence ischemic/reperfusion injury. This review focuses on newer concepts regarding PKC isoform-specific activation mechanisms and actions that have implications for the development of PKC-targeted therapeutics.
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Affiliation(s)
- Susan F Steinberg
- Department of Pharmacology, Columbia University, New York, New York, USA.
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14
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Contractile Activity Regulates Inducible Nitric Oxide Synthase Expression and NO(i) Production in Cardiomyocytes via a FAK-Dependent Signaling Pathway. JOURNAL OF SIGNAL TRANSDUCTION 2012; 2012:473410. [PMID: 22900166 PMCID: PMC3412095 DOI: 10.1155/2012/473410] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/06/2012] [Accepted: 06/06/2012] [Indexed: 11/18/2022]
Abstract
Intracellular nitric oxide (NOi) is a physiological regulator of excitation-contraction coupling, but is also involved in the development of cardiac dysfunction during hypertrophy and heart failure. To determine whether contractile activity regulates nitric oxide synthase (NOS) expression, spontaneously contracting, neonatal rat ventricular myocytes (NRVM) were treat with L-type calcium channel blockers (nifedipine and verapamil) or myosin II ATPase inhibitors (butanedione monoxime (BDM) and blebbistatin) to produce contractile arrest. Both types of inhibitors significantly reduced iNOS but not eNOS expression, and also reduced NOi production. Inhibiting contractile activity also reduced focal adhesion kinase (FAK) and AKT phosphorylation. Contraction-induced iNOS expression required FAK and phosphatidylinositol 3-kinase (PI(3)K), as both PF573228 and LY294002 (10 μM, 24 h) eliminated contraction-induced iNOS expression. Similarly, shRNAs specific for FAK (shFAK) caused FAK knockdown, reduced AKT phosphorylation at T308 and S473, and reduced iNOS expression. In contrast, shRNA-mediated knockdown of PYK2, the other member of the FAK-family of protein tyrosine kinases, had much less of an effect. Conversely, overexpression of a constitutively active form of FAK (CD2-FAK) or AKT (Myr-AKT) reversed the inhibitory effect of BDM on iNOS expression and NOi production. Thus, contraction-induced iNOS expression and NOi production in NRVM are mediated via a FAK-PI(3)K-AKT signaling pathway.
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15
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Abstract
Proline-rich tyrosine kinase 2 (Pyk2) is a nonreceptor protein kinase regulated by intracellular Ca2+, CaMK, and PKC and can be activated by different stress signals involved in heart failure. However, Pyk2 has not been investigated in the human heart, and the functional role of Pyk2 signaling at the whole heart level has not been elucidated. We hypothesize that Ca2+-dependent activation of Pyk2 is involved in cardiac electrophysiology. We examined the expression of Pyk2 in nonfailing versus ischemic and nonischemic failing human hearts ( n = 6 hearts/group). To investigate Pyk2 function, we optically mapped perfused hearts from wild-type (WT; n = 7) and knockout (Pyk2−/−; n = 8) mice during autonomic stimulation. Experiments were done in control mice and after 1 wk of transverse aortic constriction. We used the Illumina beadarray approach for transcriptional profiling of WT and Pyk2−/− mouse ventricles. Western blot analysis revealed a doubling of Pyk2 activation in nonischemic failing versus nonfailing human hearts. In mouse hearts, we observed a much higher probability of ventricular tachyarrhythmia during ACh perfusion in Pyk2−/− versus WT mice. Parasympathetic stimulation resulted in a dose-dependent decrease of atrial action potential duration (APD) in both WT and Pyk2−/− mice, whereas in ventricles it induced APD shortening in Pyk2−/− mice but not in WT mice. Deficiency of Pyk2 abolished ACh-induced prolongation of atrioventricular delay in Pyk2−/− mouse hearts but did not affect heart rate. Lower mRNA and protein levels of sarco(endo)plasmic reticulum Ca2+-ATPase 2 and higher mRNA levels of Na+/Ca2+ exchanger 1 were detected in Pyk2−/− hearts compared with WT hearts. The transverse aortic constriction protocol did not change the phenotype. In conclusion, our results indicate a protective role of Pyk2 with respect to ventricular tachyarrhythmia during parasympathetic stimulation by regulation of gene expression related to Ca2+ handling. We hypothesize that activation of Pyk2 in the human heart during heart failure may contribute to protection against arrhythmia.
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Affiliation(s)
- Di Lang
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri; and
| | - Alexey V. Glukhov
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri; and
| | - Tatiana Efimova
- Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Igor R. Efimov
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri; and
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16
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Perez DM, Doze VA. Cardiac and neuroprotection regulated by α(1)-adrenergic receptor subtypes. J Recept Signal Transduct Res 2011; 31:98-110. [PMID: 21338248 DOI: 10.3109/10799893.2010.550008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Sympathetic nervous system regulation by the α(1)-adrenergic receptor (AR) subtypes (α(1A), α(1B), α(1D)) is complex, whereby chronic activity can be either detrimental or protective for both heart and brain function. This review will summarize the evidence that this dual regulation can be mediated through the different α(1)-AR subtypes in the context of cardiac hypertrophy, heart failure, apoptosis, ischemic preconditioning, neurogenesis, locomotion, neurodegeneration, cognition, neuroplasticity, depression, anxiety, epilepsy, and mental illness.
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Affiliation(s)
- Dianne M Perez
- Department of Molecular Cardiology, NB50, The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
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17
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Park SY, Kang JH, Jeong KJ, Lee J, Han JW, Choi WS, Kim YK, Kang J, Park CG, Lee HY. Norepinephrine induces VEGF expression and angiogenesis by a hypoxia-inducible factor-1α protein-dependent mechanism. Int J Cancer 2010; 128:2306-16. [PMID: 20715173 DOI: 10.1002/ijc.25589] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 07/23/2010] [Indexed: 12/11/2022]
Abstract
A growing number of studies have demonstrated that physiological factors can influence the progression of several cancers via cellular immune function, angiogenesis and metastasis. Recently, stress-induced catecholamines have been shown to increase the expression of various cancer progressive factors, including vascular endothelial growth factor (VEGF), matrix metalloproteinases and interleukins. However, a detailed mechanism remains to be identified. In this study, we investigated the role of adrenergic receptors and hypoxia-inducible factor (HIF)-1α protein in catecholamine-induced VEGF expression and angiogenesis. Treatment of the cells with norepinephrine (NE) or isoproterenol induced VEGF expression and HIF-1α protein amount in a dose-dependent manner. Induction of VEGF expression by NE was abrogated when the cells were transfected with HIF-1α-specific siRNA. Similarly, adenylate cyclase activator forskolin and cyclic AMP-dependent protein kinase A inhibitor H-89 enhanced and decreased HIF-1α protein amount, respectively. More importantly, conditioned medium of NE-stimulated cancer cells induced angiogenesis in a HIF-1α protein-dependent manner. In addition, pretreatment of cells with propranolol, a β-adrenergic receptor (AR) blocker, completely abolished induction of VEGF expression and HIF-1α protein amount by NE in all of the tested cancer cells. However, treatment with the α1-AR blocker prazosin inhibited NE-induced HIF-1α protein amount and angiogenesis in SK-Hep1 and PC-3 but not MDA-MB-231 cells. Collectively, our results suggest that ARs and HIF-1α protein have critical roles in NE-induced VEGF expression in cancer cells, leading to stimulation of angiogenesis. These findings will help to understand the mechanism of cancer progression by stress-induced catecholamines and design therapeutic strategies for cancer angiogenesis.
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Affiliation(s)
- Soon Young Park
- Department of Pharmacology, Myunggok Medical Research Institute, College of Medicine, Konyang University, Daejeon, Republic of Korea
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18
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Shen X, Xi G, Radhakrishnan Y, Clemmons DR. PDK1 recruitment to the SHPS-1 signaling complex enhances insulin-like growth factor-i-stimulated AKT activation and vascular smooth muscle cell survival. J Biol Chem 2010; 285:29416-24. [PMID: 20643654 PMCID: PMC2937974 DOI: 10.1074/jbc.m110.155325] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 07/16/2010] [Indexed: 12/16/2022] Open
Abstract
In vascular smooth muscle cells, exposed to hyperglycemia and insulin-like growth factor-I (IGF-I), SHPS-1 functions as a scaffold protein, and a signaling complex is assembled that leads to AKT activation. However, the underlying mechanism by which formation of this complex activates the kinase that phosphorylates AKT (Thr(308)) is unknown. Therefore, we investigated the mechanism of PDK1 recruitment to the SHPS-1 signaling complex and the consequences of disrupting PDK1 recruitment for downstream signaling. Our results show that following IGF-I stimulation, PDK1 is recruited to SHPS-1, and its recruitment is mediated by Grb2, which associates with SHPS-1 via its interaction with Pyk2, a component of the SHPS-1-associated complex. A proline-rich sequence in PDK1 bound to an Src homology 3 domain in Grb2 in response to IGF-I. Disruption of Grb2-PDK1 by expression of either a Grb2 Src homology 3 domain or a PDK1 proline to alanine mutant inhibited PDK1 recruitment to SHPS-1, leading to impaired IGF-I-stimulated AKT Thr(308) phosphorylation. Following its recruitment to SHPS-1, PDK1 was further activated via Tyr(373/376) phosphorylation, and this was required for a maximal increase in PDK1 kinase activity and AKT-mediated FOXO3a Thr(32) phosphorylation. PDK1 recruitment was also required for IGF-I to prevent apoptosis that occurred in response to hyperglycemia. Assembly of the Grb2-PDK1 complex on SHPS-1 was specific for IGF-I signaling because inhibiting PDK1 recruitment to SHPS-1 had no effect on EGF-stimulated AKT Thr(308) phosphorylation. These findings reveal a novel mechanism for recruitment of PDK1 to the SHPS-1 signaling complex, which is required for IGF-I-stimulated AKT Thr(308) phosphorylation and inhibition of apoptosis.
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MESH Headings
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/metabolism
- Binding Sites
- Cell Line
- Cell Survival/drug effects
- Cells, Cultured
- GRB2 Adaptor Protein/genetics
- GRB2 Adaptor Protein/metabolism
- Humans
- Immunoblotting
- Immunoprecipitation
- In Situ Nick-End Labeling
- Insulin-Like Growth Factor I/pharmacology
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Protein Transport/drug effects
- Protein Transport/genetics
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Pyruvate Dehydrogenase Acetyl-Transferring Kinase
- RNA Interference
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Signal Transduction/drug effects
- Swine
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Affiliation(s)
- Xinchun Shen
- From the Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - Gang Xi
- From the Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - Yashwanth Radhakrishnan
- From the Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - David R. Clemmons
- From the Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
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19
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Abstract
JPs (junctophilins) contribute to the formation of junctional membrane complexes in muscle cells by physically linking the t-tubule (transverse-tubule) and SR (sarcoplasmic reticulum) membranes. In humans with HCM (hypertrophic cardiomyopathy), mutations in JP2 are linked to altered Ca2+ signalling in cardiomyocytes; however, the effects of these mutations on skeletal muscle function have not been examined. In the present study, we investigated the role of the dominant-negative JP2-S165F mutation (which is associated with human HCM) in skeletal muscle. Consistent with the hypertrophy observed in human cardiac muscle, overexpression of JP2-S165F in primary mouse skeletal myotubes led to a significant increase in myotube diameter and resting cytosolic Ca2+ concentration. Single myotube Ca2+ imaging experiments showed reductions in both the excitation-contraction coupling gain and RyR (ryanodine receptor) 1-mediated Ca2+ release from the SR. Immunoprecipitation assays revealed defects in the PKC (protein kinase C)-mediated phosphorylation of the JP2-S165F mutant protein at Ser165 and in binding of JP2-S165F to the Ca2+ channel TRPC3 (transient receptor potential cation canonical-type channel 3) on the t-tubule membrane. Therefore both the hypertrophy and altered intracellular Ca2+ signalling in the JP2-S165F-expressing skeletal myotubes can be linked to altered phosphorylation of JP2 and/or altered cross-talk among Ca2+ channels on the t-tubule and SR membranes.
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20
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Wei H, Vander Heide RS. Ischemic preconditioning and heat shock activate Akt via a focal adhesion kinase-mediated pathway in Langendorff-perfused adult rat hearts. Am J Physiol Heart Circ Physiol 2009; 298:H152-7. [PMID: 19880666 DOI: 10.1152/ajpheart.00613.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Heat stress (HS)-induced cardioprotection is associated with the activation of focal adhesion kinase (FAK) and protein kinase B (Akt) in neonatal rat ventricular myocytes (NRVMs), suggesting that stress-induced activation of survival pathways may be important in protecting intact hearts from irreversible injury. The purposes of this study were 1) to examine the subcellular signaling pathways activated by HS and ischemic preconditioning (IP) in intact hearts, 2) to determine whether HS and IP activate an integrated survival pathway similar to that activated by HS in cultured NRVMs, and 3) to determine whether HS and IP reduce lethal cell injury in perfused intact hearts. Adult rat hearts perfused in the Langendorff mode were subjected to 25 min of global ischemia and 30 min of reperfusion (I/R) either 24 h after whole animal HS or following a standard IP protocol. Myocardial signaling was analyzed using Western blot analysis, whereas cell death was assayed by measuring lactate dehydrogenase release into the perfusate and confirmed by light microscopy. Similar to NRVMs, HS performed in the whole animal 24 h before I/R increased phosphorylation of FAK at tyrosine-397 and protein kinase B (Akt) and resulted in protection from cell death. Using IP as a myocardial stress also resulted in an increased phosphorylation/activation of both FAK and Akt and resulted in reduced cell death in adult perfused rat hearts subjected to I/R. In conclusion, 1) myocardial stress caused by whole animal HS activates cytoskeletal-based survival signaling pathways in whole heart tissue and reduces lethal I/R injury and 2) IP activates the same stress-induced survival pathway and the activation correlates with the well-known cardioprotective effect of IP on lethal I/R injury.
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Affiliation(s)
- Hongguang Wei
- Department of Pathology, Wayne State University Medical School, Detroit, Michigan, USA
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21
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Raf-1: a novel cardiac troponin T kinase. J Muscle Res Cell Motil 2009; 30:67-72. [PMID: 19381846 DOI: 10.1007/s10974-009-9176-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Accepted: 04/01/2009] [Indexed: 01/20/2023]
Abstract
Phosphorylation of cardiac troponin is a key mechanism involved in regulation of contractile function. In vitro kinase assays revealed that lysates prepared from resting cardiomyocytes contain cardiac troponin I (cTnI) and cTnT kinase activity. cTnI phosphorylation is inhibited by pharmacologic inhibitors of PKA, PKC, Rho kinase and PKC effectors such as RSK and PKD; these kinase inhibitors do not inhibit phosphorylation of cTnT. Rather, cTnT phosphorylation is decreased by the Raf inhibitor GW5074. In vitro kinase assays show that recombinant Raf phosphorylates cTnT, and that Raf-dependent cTnT phosphorylation is abrogated by a T206E substitution; Raf does not phosphorylate cTnI. These studies identify Raf-dependent cTnT-Thr(206) phosphorylation as a novel mechanism that would link growth factor-dependent signaling pathways to dynamic changes in cardiac contractile function.
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22
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Ghosh SS, Krieg RJ, Sica DA, Wang R, Fakhry I, Gehr T. Cardiac hypertrophy in neonatal nephrectomized rats: the role of the sympathetic nervous system. Pediatr Nephrol 2009; 24:367-77. [PMID: 18797934 DOI: 10.1007/s00467-008-0978-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 06/29/2008] [Accepted: 07/22/2008] [Indexed: 01/08/2023]
Abstract
Cardiac hypertrophy is frequently encountered in patients with renal failure and represents an independent risk factor for cardiovascular morbidity and mortality. The pathogenesis of cardiac hypertrophy is related to multiple factors, including excess adrenergic activity. This study investigated how renal injury in the early stages of life affects the adrenergic system and thereby potentially influences cardiac growth. Biomarkers of cardiac hypertrophy were used to assess adrenergic function. Newborn male Sprague-Dawley rats were allocated to three groups of five rats each: 5/6 nephrectomy (Nx), pair-fed controls (PF), and sham-operated (SH). Nx animals had significantly higher plasma urea nitrogen, serum creatinine, and mean arterial blood pressure. The heart-weight/body-weight ratio of the Nx cohort was higher than SH and PF (p < 0.001) groups. Plasma norepinephrine (NE) of Nx animals was almost twofold higher than SH and PF (p < 0.01) animals. Compared with SH and PF, Nx animals had higher alpha1A-receptor protein expression, lower cardiac beta1- and beta2-receptor protein expression (p < 0.05), but higher G-protein-coupled receptor kinase-2 (GRK2) expression (p < 0.05). Norepinephrine transporter protein (NET) and renalase protein expression in cardiac tissue from Nx pups were significantly lower than SH and PF. Our data suggest that early age Nx animals have increased circulating catecholamines due to decreased NE metabolism. Enhancement of cardiac GRK2 and NE can contribute to cardiac hypertrophy seen in Nx animals. Furthermore, AKT (activated via alpha1A receptors), as well as increased alpha1A receptors and their agonist NE, might contribute to the observed hypertrophy.
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Affiliation(s)
- Siddhartha S Ghosh
- Division of Nephrology, VCU Medical Center, Virginia Commonwealth University, MCV Station, Box 980160, Richmond, VA, 23298-0160, USA.
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23
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García-Cazarín ML, Smith JL, Clair DKS, Piascik MT. The alpha1D-adrenergic receptor induces vascular smooth muscle apoptosis via a p53-dependent mechanism. Mol Pharmacol 2008; 74:1000-7. [PMID: 18628404 DOI: 10.1124/mol.108.047993] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Activation of the endogenous alpha1-adrenergic receptor (AR) associated with human aortic smooth muscle cells resulted in a dose- and time-dependent increase in the levels of mitochondrial reactive oxygen species (ROS). ROS increases were apparent within 10 min and maximal after 45 min. Prolonged activation (>4 h) of the alpha1-AR resulted in smooth muscle cell apoptosis. Both the increase in ROS and apoptotic cell death were blocked by the nonselective alpha1-AR antagonist prazosin as well as the selective alpha1D-AR antagonist 8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7, 9-dione (BMY 7378). Increases in ROS and apoptosis produced by alpha1-AR activation were also blocked by the p38 mitogen-activated protein kinase inhibitor 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole (SB 202190) and the NAPDH oxidase inhibitor apocynin. The extracellular signal-regulated kinase 1/2 inhibitor 2'-amino-3'-methoxyflavone (PD 98059) or the c-Jun NH2-terminal kinase inhibitor 1, 9-pyrazoloanthrone anthra(1, 9-cd)pyrazol-6(2H)-one (SP 600125) was without effect on increases in ROS levels or apoptosis. Pifithrin-alpha, an inhibitor of the tumor suppressor protein p53, had no effect on ROS generation but did block alpha1D-AR-induced apoptosis. Activation of the alpha1D-AR resulted in translocation of p53 to the mitochondria. The mitochondrial translocation of p53 was blocked by prazosin, BMY 7378, apocynin, SB 202190, and pifithrin-alpha. Apoptosis was also blocked by small interfering RNA directed against p53. These data show that the alpha1D-AR is coupled to the generation of mitochondrial ROS by a pathway involving p38 and NADPH oxidase. Sustained activation of the alpha1D-AR results in smooth muscle cell apoptosis in a pathway that involves the tumor suppressor protein p53 and the mitochondrial translocation of p53. The data also provide evidence of a linkage between the alpha1D-AR and p53.
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Affiliation(s)
- Mary L García-Cazarín
- Department of Molecular and Biomedical Pharmacology, The University of Kentucky College of Medicine, 800 Rose St., UKMC MS 305, Lexington, KY 40536-0084, USA
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24
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Block K, Eid A, Griendling KK, Lee DY, Wittrant Y, Gorin Y. Nox4 NAD(P)H oxidase mediates Src-dependent tyrosine phosphorylation of PDK-1 in response to angiotensin II: role in mesangial cell hypertrophy and fibronectin expression. J Biol Chem 2008; 283:24061-76. [PMID: 18559349 DOI: 10.1074/jbc.m803964200] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Activation of glomerular mesangial cells (MCs) by angiotensin II (Ang II) leads to hypertrophy and extracellular matrix accumulation. Here, we demonstrate that, in MCs, Ang II induces an increase in PDK-1 (3-phosphoinositide-dependent protein kinase-1) kinase activity that required its phosphorylation on tyrosine 9 and 373/376. Introduction into the cells of PDK-1, mutated on these tyrosine residues or kinase-inactive, attenuates Ang II-induced hypertrophy and fibronectin accumulation. Ang II-mediated PDK-1 activation and tyrosine phosphorylation (total and on residues 9 and 373/376) are inhibited in cells transfected with small interfering RNA for Src, indicating that Src is upstream of PDK-1. In cells expressing oxidation-resistant Src mutant C487A, Ang II-induced hypertrophy and fibronectin expression are prevented, suggesting that the pathway is redox-sensitive. Ang II also up-regulates Nox4 protein, and siNox4 abrogates the Ang II-induced increase in intracellular reactive oxygen species (ROS) generation. Small interfering RNA for Nox4 also inhibits Ang II-induced activation of Src and PDK-1 tyrosine phosphorylation (total and on residues 9 and 373/376), demonstrating that Nox4 functions upstream of Src and PDK-1. Importantly, inhibition of Nox4, Src, or PDK-1 prevents the stimulatory effect of Ang II on fibronectin accumulation and cell hypertrophy. This work provides the first evidence that Nox4-derived ROS are responsible for Ang II-induced PDK-1 tyrosine phosphorylation and activation through stimulation of Src. Importantly, this pathway contributes to Ang II-induced MC hypertrophy and fibronectin accumulation. These data shed light on molecular processes underlying the oxidative signaling cascade engaged by Ang II and identify potential targets for intervention to prevent renal hypertrophy and fibrosis.
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Affiliation(s)
- Karen Block
- Department of Medicine, University of Texas Health Science Center, 7723 Floyd Curl Drive, San Antonio, TX 78229, USA
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25
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Wei H, Vander Heide RS. Heat stress activates AKT via focal adhesion kinase-mediated pathway in neonatal rat ventricular myocytes. Am J Physiol Heart Circ Physiol 2008; 295:H561-8. [PMID: 18539755 DOI: 10.1152/ajpheart.00401.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heat stress (HS)-induced cardioprotection is associated with increased paxillin localization to the membrane fraction of neonatal rat ventricular myocytes (NRVM). The purpose of this study was 1) to examine the subcellular signaling pathways activated by HS; 2) to determine whether myocardial stress organizes and activates an integrated survival pathway; and 3) to investigate potential downstream cytoprotective proteins activated by HS. After HS, NRVM were subjected to chemical inhibitors (CI) designed to simulate ischemia by inhibiting both glycolysis and mitochondrial respiration. Protein kinase B (AKT) expression (wild type) was increased selectively with an adenoviral vector. Cell signaling was analyzed with Western blot analysis, while oncosis/apoptosis was assayed by measuring Trypan blue exclusion and/or terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining, respectively. HS increased phosphorylation of focal adhesion kinase (FAK) at tyrosine 397 but did not adversely affect the viability of NRVM before CI. HS increased association between FAK and phosphatidylinositol 3-kinase as well as causing a significant increase in AKT activity. Increased expression of wild-type AKT protected myocytes from both oncotic and apoptotic cell death. Increased expression of a FAK inhibitor, FRNK, reduced AKT phosphorylation in response to HS both at time 0 and after 10 min of CI compared with myocytes expressing empty virus. We conclude that myocardial stress activates cytoskeleton-based signaling pathways that are associated with protection from lethal cell injury.
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Affiliation(s)
- Hongguang Wei
- Dept. of Pathology, Wayne State Univ. Medical School, 540 East Canfield Ave., Detroit, MI 48201, USA
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26
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Hart DL, Heidkamp MC, Iyengar R, Vijayan K, Szotek EL, Barakat JA, Leya M, Henze M, Scrogin K, Henderson KK, Samarel AM. CRNK gene transfer improves function and reverses the myosin heavy chain isoenzyme switch during post-myocardial infarction left ventricular remodeling. J Mol Cell Cardiol 2008; 45:93-105. [PMID: 18495152 DOI: 10.1016/j.yjmcc.2008.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 04/01/2008] [Accepted: 04/07/2008] [Indexed: 12/17/2022]
Abstract
PYK2 is a Ca(2+)-dependent, nonreceptor protein tyrosine kinase that is involved in the induction of left ventricular hypertrophy (LVH) and its transition to heart failure. We and others have previously investigated PYK2's function in vitro using cultured neonatal and adult rat ventricular myocytes as model systems. However, the function of PYK2 in the in vivo adult heart remains unclear. Here we evaluate the effect of PYK2 inhibition following myocardial infarction (MI) using adenoviral (Adv) overexpression of the C-terminal domain of PYK2, known as CRNK. First we demonstrate that CRNK functions as a dominant-negative inhibitor of PYK2-dependent signaling, presumably by displacing PYK2 from focal adhesions and costameres. Then, male Sprague-Dawley rats (~300 g) underwent permanent left anterior descending coronary artery ligation. One wk post-MI, either Adv-GFP (n=34) or Adv-CRNK (n=28) was administered (10(10) pfu, 0.1 ml) via catheter-based, Optison-mediated gene transfer. LV structure and function were evaluated by echocardiography 1 and 3 wk after gene transfer, and LV tissue was analyzed by real-time RT-PCR and Western blotting. CRNK overexpression was readily detected by Western blotting 1 wk following gene transfer. Adv-CRNK improved overall survival (P=0.03; Logrank Test) and LV fractional shortening (23+/-2% vs. 31+/-2% for Adv-GFP vs. Adv-CRNK infected animals, respectively; P<0.05). Whereas MI hearts exhibited increased beta-, and decreased alpha-myosin heavy chain (MHC) mRNA expression characteristic of LVH, Adv-CRNK reversed the MHC isoenzyme switch (3.3+/-1.4 fold increase in alpha MHC; 0.4+/-0.1 fold decrease in beta MHC; P<0.05 for both). In summary, CRNK gene transfer improves survival, increases LV function, and alters MHC gene expression suggesting an attenuation of LV remodeling post-MI.
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Affiliation(s)
- Davin L Hart
- The Cardiovascular Institute, Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, Illinois 60153, USA
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27
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Zhuo W, Wang Y, Zhuo X, Zhang Y, Ao X, Chen Z. Knockdown of Snail, a novel zinc finger transcription factor, via RNA interference increases A549 cell sensitivity to cisplatin via JNK/mitochondrial pathway. Lung Cancer 2008; 62:8-14. [PMID: 18372076 DOI: 10.1016/j.lungcan.2008.02.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 02/05/2008] [Accepted: 02/14/2008] [Indexed: 12/13/2022]
Abstract
Previous reports have implicated epithelial-mesenchymal transition (EMT) as a major cause of cancer. Snail, a novel zinc finger transcription factor, was suggested to be an important inducer of EMT and therefore be involved in different phases of tumorigenicity. However, whether Snail could increase chemoresistance of cancer cells to chemotherapeutic agent remains unclear. To evaluate the roles and possible mechanisms of Snail in chemoresistance of lung cancer cells to cisplatin, we utilized RNA interference to knockdown Snail expression in A549 cells and further assessed the cell viability and apoptosis as well as possible signaling transduction pathways. The data showed that Snail depletion sensitized A549 cells to cisplatin possibly by inducing activation of JNK/mitochondrial pathway, suggesting critical roles of Snail in A549 cell chemoresistance to cisplatin and raising the possibility of Snail depletion as a promising approach to lung cancer therapy.
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Affiliation(s)
- Wenlei Zhuo
- Institute of Cancer, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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28
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Small interference RNA against PTP-1B reduces hypoxia/reoxygenation induced apoptosis of rat cardiomyocytes. Apoptosis 2008; 13:383-93. [DOI: 10.1007/s10495-008-0181-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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Murtaza I, Wang HX, Feng X, Alenina N, Bader M, Prabhakar BS, Li PF. Down-regulation of catalase and oxidative modification of protein kinase CK2 lead to the failure of apoptosis repressor with caspase recruitment domain to inhibit cardiomyocyte hypertrophy. J Biol Chem 2008; 283:5996-6004. [PMID: 18171680 DOI: 10.1074/jbc.m706466200] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cardiac hypertrophy is regulated by a complex interplay of pro- and anti-hypertrophic factors. Here, we report a novel anti-hypertrophic pathway composed of catalase, protein kinase CK2 (CK2), and apoptosis repressor with caspase recruitment domain (ARC). Our results showed that ARC phosphorylation levels, CK2 activity, and catalase expression levels were decreased in the hearts of the angiotensinogen transgenic mice and in cardiomyocytes treated with the hypertrophic stimuli, including phenylephrine, tumor necrosis factor-alpha, and angiotensin II. To understand the role of ARC in hypertrophy, we observed that enforced expression of ARC could inhibit hypertrophy. Knockdown of endogenous ARC or inhibition of its phosphorylation could sensitize cardiomyocytes to undergoing hypertrophy. The phosphorylatable, but not the nonphosphorylatable, ARC could inhibit hypertrophy. Thus, ARC is able to inhibit hypertrophy in a phosphorylation-dependent manner. In exploring the molecular mechanism by which CK2 activity is reduced, we found that CK2 was carbonylated in angiotensinogen transgenic mice and in cardiomyocytes treated with the hypertrophic stimuli. The decrease in catalase expression led to an elevated level of reactive oxygen species. The latter oxidatively modified CK2, resulting in its carbonylation. CK2 lost its catalytic activity upon carbonylation. ARC is phosphorylated by CK2, and ARC phosphorylation levels were reduced as a consequence of the decrease of CK2 activity. To understand the molecular mechanism by which ARC inhibits hypertrophy, we observed that ARC could inhibit the activation of mitochondrial permeability transition. These results suggest that catalase, CK2, and ARC constitute an anti-hypertrophic pathway in the heart.
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Affiliation(s)
- Iram Murtaza
- Division of Cardiovascular Research, National Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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