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Mohammed Abdul KS, Han K, Guerrero AB, Wilson CN, Kulkarni A, Purcell NH. Increased PHLPP1 expression through ERK-4E-BP1 signaling axis drives nicotine induced oxidative stress related damage of cardiomyocytes. J Mol Cell Cardiol 2024; 193:100-112. [PMID: 38851627 DOI: 10.1016/j.yjmcc.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/10/2024]
Abstract
Nicotine, a key constituent of tobacco/electronic cigarettes causes cardiovascular injury and mortality. Nicotine is known to induce oxidative stress and mitochondrial dysfunction in cardiomyocytes leading to cell death. However, the underlying mechanisms remain unclear. Pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) is a member of metal-dependent protein phosphatase (PPM) family and is known to dephosphorylate several AGC family kinases and thereby regulate a diverse set of cellular functions including cell growth, survival, and death. Our lab has previously demonstrated that PHLPP1 removal reduced cardiomyocyte death and cardiac dysfunction following injury. Here, we present a novel finding that nicotine exposure significantly increased PHLPP1 protein expression in the adolescent rodent heart. Building upon our in vivo finding, we determined the mechanism of PHLPP1 expression in cardiomyocytes. Nicotine significantly increased PHLPP1 protein expression without altering PHLPP2 in cardiomyocytes. In cardiomyocytes, nicotine significantly increased NADPH oxidase 4 (NOX4), which coincided with increased reactive oxygen species (ROS) and increased cardiomyocyte apoptosis which were dependent on PHLPP1 expression. PHLPP1 expression was both necessary and sufficient for nicotine induced mitochondrial dysfunction. Mechanistically, nicotine activated extracellular signal-regulated protein kinases (ERK1/2) and subsequent eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) to increase PHLPP1 protein expression. Inhibition of protein synthesis with cycloheximide (CHX) and 4EGI-1 abolished nicotine induced PHLPP1 protein expression. Moreover, inhibition of ERK1/2 activity by U0126 significantly blocked nicotine induced PHLPP1 expression. Overall, this study reveals a novel mechanism by which nicotine regulates PHLPP1 expression through ERK-4E-BP1 signaling axis to drive cardiomyocyte injury.
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Affiliation(s)
| | - Kimin Han
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Alyssa B Guerrero
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Cekia N Wilson
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Amogh Kulkarni
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Nicole H Purcell
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA; Cardiovascular Division, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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Rico A, Valls A, Guembelzu G, Azpitarte M, Aiastui A, Zufiria M, Jaka O, López de Munain A, Sáenz A. Altered expression of proteins involved in metabolism in LGMDR1 muscle is lost in cell culture conditions. Orphanet J Rare Dis 2023; 18:315. [PMID: 37817200 PMCID: PMC10565977 DOI: 10.1186/s13023-023-02873-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/24/2023] [Indexed: 10/12/2023] Open
Abstract
BACKGROUND Limb-girdle muscular dystrophy R1 calpain 3-related (LGMDR1) is an autosomal recessive muscular dystrophy due to mutations in the CAPN3 gene. While the pathophysiology of this disease has not been clearly established yet, Wnt and mTOR signaling pathways impairment in LGMDR1 muscles has been reported. RESULTS A reduction in Akt phosphorylation ratio and upregulated expression of proteins implicated in glycolysis (HK-II) and in fructose and lactate transport (GLUT5 and MCT1) in LGMDR1 muscle was observed. In vitro analysis to establish mitochondrial and glycolytic functions of primary cultures were performed, however, no differences between control and patients were observed. Additionally, gene expression analysis showed a lack of correlation between primary myoblasts/myotubes and LGMDR1 muscle while skin fibroblasts and CD56- cells showed a slightly better correlation with muscle. FRZB gene was upregulated in all the analyzed cell types (except in myoblasts). CONCLUSIONS Proteins implicated in metabolism are deregulated in LGMDR1 patients' muscle. Obtained results evidence the limited usefulness of primary myoblasts/myotubes for LGMDR1 gene expression and metabolic studies. However, since FRZB is the only gene that showed upregulation in all the analyzed cell types it is suggested its role as a key regulator of the pathophysiology of the LGMDR1 muscle fiber. The Wnt signaling pathway inactivation, secondary to FRZB upregulation, and GLUT5 overexpression may participate in the impaired adipogenesis in LGMD1R patients.
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Affiliation(s)
- Anabel Rico
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain
| | - Andrea Valls
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain
| | - Garazi Guembelzu
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain
| | - Margarita Azpitarte
- Cell Culture, Histology and Multidisciplinary 3D Printing Platform, Biodonostia Health Research Institute, San Sebastián, Spain
| | - Ana Aiastui
- Department of Neurology, Donostialdea Integrated Health Organization, San Sebastián, Spain
| | - Mónica Zufiria
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain
| | - Oihane Jaka
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain
| | - Adolfo López de Munain
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain
- Department of Neurology, Donostialdea Integrated Health Organization, San Sebastián, Spain
- Department of Neurosciences, University of the Basque Country UPV-EHU, San Sebastián, Spain
- Faculty of Medicine, University of Deusto, Bilbao, Spain
| | - Amets Sáenz
- Neurosciences Area, Biodonostia Health Research Institute, San Sebastián, Spain.
- CIBERNED, CIBER, Spanish Ministry of Science and Innovation, Carlos III Health Institute, Madrid, Spain.
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Zhang R. Mitochondrial proteins that connected with calcium: do their pathways changes in PAH? BIO WEB OF CONFERENCES 2022. [DOI: 10.1051/bioconf/20225501018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Calcium can be regulated by mitochondria and also plays a significant role in mitochondrial pathways. Recent study showed mitochondrial protein changes in the right ventricle in pulmonary arterial hypertension, which affects calcium network at the same time. The specific objective of this study is to assess the pathway of calcium transport by permeable pore in mitochondria and investigate the regulation of mitochondrial proteins in order to find the connection between mitochondrial proteins and right ventricular dysfunction in PAH (pulmonary arterial hypertension). This literature-based review came out by searching articles in Pubmed and Science Direct. And the related flow chart is expressed by the form of PRISMA. There is a network between mitochondria and calcium through the transport chain called mitochondria permeability transition pore (MPTP) as well as different kinds of proteins that are located in the mitochondria. MPTP is a kind of mitochondria pore and can have conformational changes after protein phosphorylation or reaction between mitochondrial proteins to activate the apoptosis capase cascade process in cell death. In addition, MPTP can be activated by other mitochondrial protein like signal transducer activator of transcription3 (STAT3) to activate cytochrome c in pro-apoptosis to initiate cell death at the same time. The most obvious finding from this study is the role of calcium regulation in therapeutic treatment in PAH patients, which suggest an imaginable role for calcium transporter like mitochondria calcium uniporter (MCU) promoting bio-markers in cardiovascular disease resulting from mitochondrial dysfunction. In addition, right ventricle is a target of PAH in which mitochondria in RV would play an essential role in pathways such as ATP production via mitochondria metabolism.
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Molecular Signaling to Preserve Mitochondrial Integrity against Ischemic Stress in the Heart: Rescue or Remove Mitochondria in Danger. Cells 2021; 10:cells10123330. [PMID: 34943839 PMCID: PMC8699551 DOI: 10.3390/cells10123330] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular diseases are one of the leading causes of death and global health problems worldwide, and ischemic heart disease is the most common cause of heart failure (HF). The heart is a high-energy demanding organ, and myocardial energy reserves are limited. Mitochondria are the powerhouses of the cell, but under stress conditions, they become damaged, release necrotic and apoptotic factors, and contribute to cell death. Loss of cardiomyocytes plays a significant role in ischemic heart disease. In response to stress, protective signaling pathways are activated to limit mitochondrial deterioration and protect the heart. To prevent mitochondrial death pathways, damaged mitochondria are removed by mitochondrial autophagy (mitophagy). Mitochondrial quality control mediated by mitophagy is functionally linked to mitochondrial dynamics. This review provides a current understanding of the signaling mechanisms by which the integrity of mitochondria is preserved in the heart against ischemic stress.
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Salicylic diamines selectively eliminate residual undifferentiated cells from pluripotent stem cell-derived cardiomyocyte preparations. Sci Rep 2021; 11:2391. [PMID: 33504837 PMCID: PMC7841182 DOI: 10.1038/s41598-021-81351-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 12/14/2020] [Indexed: 02/06/2023] Open
Abstract
Clinical translation of pluripotent stem cell (PSC) derivatives is hindered by the tumorigenic risk from residual undifferentiated cells. Here, we identified salicylic diamines as potent agents exhibiting toxicity to murine and human PSCs but not to cardiomyocytes (CMs) derived from them. Half maximal inhibitory concentrations (IC50) of small molecules SM2 and SM6 were, respectively, 9- and 18-fold higher for human than murine PSCs, while the IC50 of SM8 was comparable for both PSC groups. Treatment of murine embryoid bodies in suspension differentiation cultures with the most effective small molecule SM6 significantly reduced PSC and non-PSC contamination and enriched CM populations that would otherwise be eliminated in genetic selection approaches. All tested salicylic diamines exerted their toxicity by inhibiting the oxygen consumption rate (OCR) in PSCs. No or only minimal and reversible effects on OCR, sarcomeric integrity, DNA stability, apoptosis rate, ROS levels or beating frequency were observed in PSC-CMs, although effects on human PSC-CMs seemed to be more deleterious at higher SM-concentrations. Teratoma formation from SM6-treated murine PSC-CMs was abolished or delayed compared to untreated cells. We conclude that salicylic diamines represent promising compounds for PSC removal and enrichment of CMs without the need for other selection strategies.
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Ohwada W, Tanno M, Yano T, Ong SB, Abe K, Sato T, Kuno A, Miki T, Sugawara H, Igaki Y, Miura T. Distinct intra-mitochondrial localizations of pro-survival kinases and regulation of their functions by DUSP5 and PHLPP-1. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165851. [PMID: 32480039 DOI: 10.1016/j.bbadis.2020.165851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/14/2020] [Accepted: 05/26/2020] [Indexed: 01/03/2023]
Abstract
ERK and Akt have been shown to regulate cell sensitivity to death-inducing stress by phosphorylating GSK-3β, a major modulator of the threshold for mitochondrial permeability transition. Here we examined intra-mitochondrial localization of the pro-survival kinases and their regulation by phosphatases. Stepwise trypsin digestion of mitochondria isolated from HEK293 or H9c2 cells was performed, and immunoblotting revealed that GSK-3β and ERK localized dominantly in the outer membrane (OM), while Akt resided at comparable levels in OM, the inner membrane (IM) and the matrix. Treatment with IGF-1 increased the protein level of Akt in the matrix, while ERK and GSK-3β protein levels were increased in OM. Simultaneously, IGF-1 treatment elevated the level of Thr202/Tyr204-phospho-ERK in IM and matrix and levels of Ser473-phospho-Akt and Ser9-phospho-GSK-3β in OM, IM and matrix. Exposing cells to reactive oxygen species (ROS) by using antimycin A increased the levels of DUSP5 and PHLPP-1 mainly in OM and induced dephosphorylation of Akt, ERK and GSK-3β. The mitochondrial localization of DUSP5 was confirmed by experiments with mitochondria purified by Percoll gradient centrifugation and by transfection of cells with GFP-tagged DUSP5. Knockdown of either DUSP5 or PHLPP-1 increased the levels of both Thr202/Tyr204-phospho-ERK and Ser473-phospho-Akt in mitochondria. Cell death induced by antimycin A was suppressed by siRNA-mediated knockdown of DUSP5. The results suggest that Akt and ERK in mitochondria show distinct intra-mitochondrial localization and crosstalk in GSK-3β regulation and that recruitment of DUSP5 as well as PHLPP-1 to mitochondria contributes to ROS-induced termination of the protective signaling.
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Affiliation(s)
- Wataru Ohwada
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masaya Tanno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Toshiyuki Yano
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Sang-Bing Ong
- Signature Research Program in Cardiovascular & Metabolic Diseases, Duke-NUS Medical School, Singapore
| | - Koki Abe
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tatsuya Sato
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Cellular Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Atsushi Kuno
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Pharmacology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takayuki Miki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hirohito Sugawara
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yusuke Igaki
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
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Mitochondrial Akt Signaling Modulated Reprogramming of Somatic Cells. Sci Rep 2019; 9:9919. [PMID: 31289326 PMCID: PMC6616364 DOI: 10.1038/s41598-019-46359-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 06/27/2019] [Indexed: 12/13/2022] Open
Abstract
The signaling mechanisms controlling somatic cell reprogramming are not fully understood. In this study, we report a novel role for mitochondrial Akt1 signaling that enhanced somatic cell reprogramming efficiency. The role of mitochondrial Akt1 in somatic cell reprogramming was investigated by transducing fibroblasts with the four reprogramming factors (Oct4, Sox2, Klf4, c-Myc) in conjunction with Mito-Akt1, Mito-dnAkt1, or control virus. Mito-Akt1 enhanced reprogramming efficiency whereas Mito-dnAkt1 inhibited reprogramming. The resulting iPSCs formed embryoid bodies in vitro and teratomas in vivo. Moreover, Oct4 and Nanog promoter methylation was reduced in the iPSCs generated in the presence of Mito-Akt1. Akt1 was activated and translocated into mitochondria after growth factor stimulation in embryonic stem cells (ESCs). To study the effect of mitochondrial Akt in ESCs, a mitochondria-targeting constitutively active Akt1 (Mito-Akt1) was expressed in ESCs. Gene expression profiling showed upregulation of genes that promote stem cell proliferation and survival and down-regulation of genes that promote differentiation. Analysis of cellular respiration indicated similar metabolic profile in the resulting iPSCs and ESCs, suggesting comparable bioenergetics. These findings showed that activation of mitochondrial Akt1 signaling was required during somatic cell reprogramming.
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The regulatory mechanisms of Yulangsan MHBFC reversing cardiac remodeling in rats based on eNOS-NO signaling pathway. Biomed Pharmacother 2019; 117:109141. [PMID: 31228800 DOI: 10.1016/j.biopha.2019.109141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 11/20/2022] Open
Abstract
Millettia pulchra Kurz var-laxior (Dunn) Z. Wei, a wild-growing plant of the family Fabaceae is known to possess multifarious medicinal properties. 17-Methoxyl-7-hydroxy-benzene-furanchalcone (MHBFC) is a flavonoid monomer extracted from its root, which has been used in traditional Chinese medicine, with a long history as a remedy of hypertension and cardiovascular remodeling. The present study was conducted to further investigate the regulatory mechanisms of MHBFC based on the endothelial nitric oxide synthase-nitric oxide (eNOS-NO) signaling pathway. The abdominal aorta of the male Sprague-Dawley rats was narrowed to induce cardiac remodeling, and the rats were given corresponding drugs for 6 weeks after operation. At the end of the experiment, the relevant indexes were detected. The results showed that Nω-nitro-L-arginine methyl ester (L-NAME) could increase the myocardial cell cross-section area, myocardial fibrosis, and the cardiac collagen volume fraction. The serum NO and eNOS levels and the expression of p-eNOS, p-PI3K and p-Akt protein were decreased, and myocardial microvascular endothelial cell (MMVEC) apoptosis increased. However, the above changes were reversed after treatment with MHBFC. These results indicated that MHBFC could increase eNOS protein phosphorylation by increasing PI3K and Akt protein phosphorylation, and activated the eNOS-NO signaling pathway, increased eNOS enzyme activity, catalyzed the generation of protective NO, and counteracted MMVEC apoptosis induced by cardiac remodeling, thereby protecting against myocardial damage and reversing cardiac remodeling.
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Aweya JJ, Wang W, Zhang Y, Yao D, Li S, Wang F. Identification and molecular characterization of the Pim1 serine/threonine kinase homolog in Litopenaeus vannamei. FISH & SHELLFISH IMMUNOLOGY 2018; 74:491-500. [PMID: 29355758 DOI: 10.1016/j.fsi.2018.01.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/08/2018] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
The Pim1 serine/threonine kinase is associated with multiple cellular functions including proliferation, survival, differentiation, apoptosis, tumorigenesis, immune regulation and inflammation in vertebrates. However, little is known about the role of Pim1 in invertebrate immunity. In this study, we identified and characterized for the first time, a Pim1 (LvPim1) gene in Litopenaeus vannamei, with a full-length cDNA of 2352 bp and a 1119 bp open reading frame (ORF) encoding a putative protein of 372 amino acids, which contains a typical serine/threonine kinase domain. Sequence and phylogenetic analysis revealed that LvPim1 shared a close evolutionary relationship with Pim1 from vertebrates. Real-time qPCR analysis showed that LvPim1 was widely expressed in all tissues tested; with its transcript level induced in hepatopancreas and hemocytes upon challenge with Vibrio parahaemolyticus, Streptoccocus iniae, lipopolysaccharide (LPS), and white spot syndrome virus (WSSV), thus, suggesting its probable involvement in shrimp immune response. Moreover, knockdown of LvPim1 resulted in increased hemocytes apoptosis; shown by high caspase3/7 activity, coupled with increase in pro-apoptotic LvCaspase3 and LvCytochrome C, and decrease in pro-survival LvBcl2, LvIAP1, and LvIAP2 mRNA expression in hemocytes. Finally, LvPim1 knockdown renders shrimps more susceptible to V. parahaemolyticus infection. Taken together, our present data strongly suggest that LvPim1 is involved in modulating shrimp resistance to pathogen infection, promote hemocytes survival, and therefore plays a role in shrimp immune response.
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Affiliation(s)
- Jude Juventus Aweya
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Wei Wang
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Yueling Zhang
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Defu Yao
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Shengkang Li
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Fan Wang
- Department of Biology and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China.
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Nitrite administration improves sepsis-induced myocardial and mitochondrial dysfunction by modulating stress signal responses. J Anesth 2017; 31:885-894. [PMID: 29063286 DOI: 10.1007/s00540-017-2417-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022]
Abstract
PURPOSE A specific therapeutic strategy in sepsis-induced myocardial dysfunction remains to be determined. Nitrite may have cardioprotective effects against sepsis-induced myocardial dysfunction. This study investigated the cardioprotective effects of nitrite on myocardial function, mitochondrial bioenergetics, and its underlying molecular mechanisms in severe septic rats. METHODS Sepsis was induced in male Wistar rats by cecal ligation and puncture (CLP). After CLP, we administered normal saline (NS group) or nitrite (nitrite group) subcutaneously. We administered nitrite at different doses (0.1-10 mg/kg) to ascertain the most effective dose and examined cardiac function in an isolated heart experiment 8 h after CLP. We investigated mitochondrial bioenergetics and molecular mechanisms underlying the administration of nitrite in vitro. RESULTS In isolated heart experiments, the left ventricular developed pressure (96 ± 5 mmHg) at a moderate nitrite dose (1.0 mg/kg) was significantly higher than that in the NS group (75 ± 4 mmHg, P < 0.05). Mitochondrial oxidative phosphorylation in the nitrite group was significantly higher than that in the NS group (P < 0.01). Immunoblotting revealed that nitrite significantly increased the phosphorylation of Akt (P < 0.05) and reduced the nuclear translocation of NF-κB (P < 0.05) compared with the NS group. Nitrite was also shown to improve the rate of survival in severe septic rats (P < 0.001). CONCLUSIONS Our results showed that a moderate nitrite dose improved septic myocardial dysfunction at organ, cellular, and molecular levels via modulation of stress signal responses, which resulted in an improvement in survival.
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Martins Peçanha FL, Dos Santos RS, da-Silva WS. Thyroid states regulate subcellular glucose phosphorylation activity in male mice. Endocr Connect 2017; 6:311-322. [PMID: 28483784 PMCID: PMC5510448 DOI: 10.1530/ec-17-0059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 12/15/2022]
Abstract
The thyroid hormones (THs), triiodothyronine (T3) and thyroxine (T4), are very important in organism metabolism and regulate glucose utilization. Hexokinase (HK) is responsible for the first step of glycolysis, catalyzing the conversion of glucose to glucose 6-phosphate. HK has been found in different cellular compartments, and new functions have been attributed to this enzyme. The effects of hyperthyroidism on subcellular glucose phosphorylation in mouse tissues were examined. Tissues were removed, subcellular fractions were isolated from eu- and hyperthyroid (T3, 0.25 µg/g, i.p. during 21 days) mice and HK activity was assayed. Glucose phosphorylation was increased in the particulate fraction in soleus (312.4% ± 67.1, n = 10), gastrocnemius (369.2% ± 112.4, n = 10) and heart (142.2% ± 13.6, n = 10) muscle in the hyperthyroid group compared to the control group. Hexokinase activity was not affected in brain or liver. No relevant changes were observed in HK activity in the soluble fraction for all tissues investigated. Acute T3 administration (single dose of T3, 1.25 µg/g, i.p.) did not modulate HK activity. Interestingly, HK mRNA levels remained unchanged and HK bound to mitochondria was increased by T3 treatment, suggesting a posttranscriptional mechanism. Analysis of the AKT pathway showed a 2.5-fold increase in AKT and GSK3B phosphorylation in the gastrocnemius muscle in the hyperthyroid group compared to the euthyroid group. Taken together, we show for the first time that THs modulate HK activity specifically in particulate fractions and that this action seems to be under the control of the AKT and GSK3B pathways.
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Affiliation(s)
- Flavia Letícia Martins Peçanha
- Instituto de Bioquímica Médica Leopoldo de MeisLaboratório de Adaptações Metabólicas, Programa de Bioquímica e Biofísica Celular, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Reinaldo Sousa Dos Santos
- Instituto de Bioquímica Médica Leopoldo de MeisLaboratório de Adaptações Metabólicas, Programa de Bioquímica e Biofísica Celular, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wagner Seixas da-Silva
- Instituto de Bioquímica Médica Leopoldo de MeisLaboratório de Adaptações Metabólicas, Programa de Bioquímica e Biofísica Celular, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Rio de Janeiro, Brazil
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12
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Yu W, Ni Y, Saji M, Ringel MD, Jaini R, Eng C. Cowden syndrome-associated germline succinate dehydrogenase complex subunit D (SDHD) variants cause PTEN-mediated down-regulation of autophagy in thyroid cancer cells. Hum Mol Genet 2017; 26:1365-1375. [PMID: 28164237 PMCID: PMC5390680 DOI: 10.1093/hmg/ddx037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/23/2017] [Indexed: 12/19/2022] Open
Abstract
Thyroid cancer is a major component cancer of Cowden syndrome (CS), a disorder typically associated with germline mutations in PTEN. Germline variants in succinate dehydrogenase genes (SDHx) co-occurring with PTEN germline mutations confer a 2-fold increased prevalence (OR 2.7) of thyroid cancer compared to PTEN-associated CS but 50% decreased prevalence (OR 0.54) of thyroid cancer compared to SDHx-associated CS. We have previously shown that CS-associated SDHD variants G12S and H50R induce PTEN oxidation and nuclear accumulation in thyroid cancer. Our current study shows that SDHD-G12S and -H50R variants cause down-regulation of autophagy, demonstrating a role for SDHD in autophagy-associated pathogenesis of differentiated thyroid cancer. These findings could explain the increased prevalence of thyroid cancer in CS patients with SDHx germline mutations compared to those with PTEN mutations alone. Importantly, we demonstrate the dependence of this process on functional wild-type PTEN with reversal of decreased autophagy after PTEN knockdown. The latter could explain the clinically observed decrease in thyroid cancer prevalence in patients with co-existent PTEN mutations and SDHx variants. We also show that SDHD-G12S/H50R promotes mono-ubiquitination of PTEN, causing its translocation into the nucleus, upregulation of AKT and consequent phosphorylation of FOXO3a. Furthermore, SDHD-G12S/H50R-mediated increase in acetylation of FOXO3a further enhances AKT-associated phosphorylation of FOXO3a. This combination of phosphorylation and acetylation of FOXO3a results in its nuclear export for degradation and consequent down-regulation of FOXO3a-target autophagy-related gene (ATG) expression. Overall, our study reveals a novel mechanism of crosstalk amongst SDHD, PTEN and autophagy pathways and their potential roles in thyroid carcinogenesis.
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Affiliation(s)
- Wanfeng Yu
- Genomic Medicine Institute.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ying Ni
- Genomic Medicine Institute.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Motoyasu Saji
- Division of Endocrinology and Metabolism, Department of Internal Medicine.,Molecular Biology and Cancer Genetics Program, Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Matthew D Ringel
- Division of Endocrinology and Metabolism, Department of Internal Medicine.,Molecular Biology and Cancer Genetics Program, Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Ritika Jaini
- Genomic Medicine Institute.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Germline High Risk Focus Group, CASE Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Charis Eng
- Genomic Medicine Institute.,Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Germline High Risk Focus Group, CASE Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.,Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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13
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In vivo cardiomyocyte response to YTX- and AZA-1-induced damage: autophagy versus apoptosis. Arch Toxicol 2016; 91:1859-1870. [DOI: 10.1007/s00204-016-1862-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 09/28/2016] [Indexed: 10/20/2022]
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Brody MJ, Lee Y. The Role of Leucine-Rich Repeat Containing Protein 10 (LRRC10) in Dilated Cardiomyopathy. Front Physiol 2016; 7:337. [PMID: 27536250 PMCID: PMC4971440 DOI: 10.3389/fphys.2016.00337] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/20/2016] [Indexed: 12/12/2022] Open
Abstract
Leucine-rich repeat containing protein 10 (LRRC10) is a cardiomyocyte-specific member of the Leucine-rich repeat containing (LRRC) protein superfamily with critical roles in cardiac function and disease pathogenesis. Recent studies have identified LRRC10 mutations in human idiopathic dilated cardiomyopathy (DCM) and Lrrc10 homozygous knockout mice develop DCM, strongly linking LRRC10 to the molecular etiology of DCM. LRRC10 localizes to the dyad region in cardiomyocytes where it can interact with actin and α-actinin at the Z-disc and associate with T-tubule components. Indeed, this region is becoming increasingly recognized as a signaling center in cardiomyocytes, not only for calcium cycling, excitation-contraction coupling, and calcium-sensitive hypertrophic signaling, but also as a nodal signaling hub where the myocyte can sense and respond to mechanical stress. Disruption of a wide range of critical structural and signaling molecules in cardiomyocytes confers susceptibility to cardiomyopathies in addition to the more classically studied mutations in sarcomeric proteins. However, the molecular mechanisms underlying DCM remain unclear. Here, we review what is known about the cardiomyocyte functions of LRRC10, lessons learned about LRRC10 and DCM from the Lrrc10 knockout mouse model, and discuss ongoing efforts to elucidate molecular mechanisms whereby mutation or absence of LRRC10 mediates cardiac disease.
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Affiliation(s)
- Matthew J Brody
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center Cincinnati, OH, USA
| | - Youngsook Lee
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Madison, WI, USA
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15
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Shuai XX, Meng YD, Lu YX, Su GH, Tao XF, Han J, Xu SD, Luo P. Relaxin-2 improves diastolic function of pressure-overloaded rats via phospholamban by activating Akt. Int J Cardiol 2016; 218:305-311. [PMID: 27240156 DOI: 10.1016/j.ijcard.2016.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 04/18/2016] [Accepted: 05/12/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND Relaxin is a peptide hormone which has been demonstrated to be safe and has a therapeutic effect on acute heart failure in clinic trials. However, its effect on diastolic function is still unknown. The aims of the study were to determine whether relaxin could improve the diastolic function in pressure-overloaded rat model and to analyze potential mechanisms. METHODS AND RESULTS In the present study, a pressure-overloaded rat model induced by transaortic constriction (TAC) was established. Four weeks after TAC, echocardiography was performed and then all the rat models were randomly divided into 3 groups: models without intramyocardial injection (TAC), with intramyocardial injection of empty adenoviral vector (TAC+GFP) and adenoviral vector overexpression relaxin-2 gene (TAC+RLN2). A sham group was also included. Twelve days after intramyocardial injection, echocardiography and hemodynamics were carried out to evaluate diastolic function in sham, TAC, TAC+GFP and TAC+RLN2 groups. Then hearts were harvested for subsequent examinations. The results indicated that relaxin-2 had ameliorated diastolic function in the pressure-overloaded rats. Compared with the TAC and TAC+GFP groups, the relaxin-2 gene transfer increased phosphorylation of Akt at both the Ser473 and Thr308 sites. Meanwhile, it increased the Ser16 and Thr17- phosphorylation levels of phospholamban (PLB). Furthermore, SERCA2 activity was enhanced in the TAC+RLN2 group more than in the TAC and TAC+GFP groups. CONCLUSIONS These results demonstrated that relaxin-2 gene therapy improved diastolic function in pressure-overloaded rats. The potential mechanism may be that relaxin-2 gene transfer enhances SERCA2 activity in hearts by increasing phospholamban phosphorylation through nuclear-targeted Akt phosphorylation.
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Affiliation(s)
- Xin-Xin Shuai
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yi-di Meng
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yong-Xin Lu
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China.
| | - Guan-Hua Su
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xiao-Fang Tao
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jun Han
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Su-Dan Xu
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ping Luo
- Department of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430022, China
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16
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Ho N, Morrison J, Silva A, Coomber BL. The effect of 3-bromopyruvate on human colorectal cancer cells is dependent on glucose concentration but not hexokinase II expression. Biosci Rep 2016; 36:e00299. [PMID: 26740252 PMCID: PMC4759612 DOI: 10.1042/bsr20150267] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 12/16/2015] [Accepted: 01/06/2016] [Indexed: 12/21/2022] Open
Abstract
Cancer cells heavily rely on the glycolytic pathway regardless of oxygen tension. Hexokinase II (HKII) catalyses the first irreversible step of glycolysis and is often overexpressed in cancer cells. 3-Bromopyruvate (3BP) has been shown to primarily target HKII, and is a promising anti-cancer compound capable of altering critical metabolic pathways in cancer cells. Abnormal vasculature within tumours leads to heterogeneous microenvironments, including glucose availability, which may affect drug sensitivity. The aim of the present study was to elucidate the mechanisms by which 3BP acts on colorectal cancer (CRC) cells with focus on the HKII/Akt signalling axis. High HKII-expressing cell lines were more sensitive to 3BP than low HKII-expressing cells. 3BP-induced rapid Akt phosphorylation at site Thr-308 and cell death via both apoptotic and necrotic mechanisms. Cells grown under lower glucose concentrations showed greater resistance towards 3BP. Cells with HKII knockdown showed no changes in 3BP sensitivity, suggesting the effects of 3BP are independent of HKII expression. These results emphasize the importance of the tumour microenvironment and glucose availability when considering therapeutic approaches involving metabolic modulation.
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Affiliation(s)
- Nelson Ho
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Jodi Morrison
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Andreza Silva
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Brenda L Coomber
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, N1G 2W1
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17
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Beyer AM, Freed JK, Durand MJ, Riedel M, Ait-Aissa K, Green P, Hockenberry JC, Morgan RG, Donato AJ, Peleg R, Gasparri M, Rokkas CK, Santos JH, Priel E, Gutterman DD. Critical Role for Telomerase in the Mechanism of Flow-Mediated Dilation in the Human Microcirculation. Circ Res 2015; 118:856-66. [PMID: 26699654 PMCID: PMC4772813 DOI: 10.1161/circresaha.115.307918] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/21/2015] [Indexed: 02/02/2023]
Abstract
RATIONALE Telomerase is a nuclear regulator of telomere elongation with recent reports suggesting a role in regulation of mitochondrial reactive oxygen species. Flow-mediated dilation in patients with cardiovascular disease is dependent on the formation of reactive oxygen species. OBJECTIVE We examined the hypothesis that telomerase activity modulates microvascular flow-mediated dilation, and loss of telomerase activity contributes to the change of mediator from nitric oxide to mitochondrial hydrogen peroxide in patients with coronary artery disease (CAD). METHODS AND RESULTS Human coronary and adipose arterioles were isolated for videomicroscopy. Flow-mediated dilation was measured in vessels pretreated with the telomerase inhibitor BIBR-1532 or vehicle. Statistical differences between groups were determined using a 2-way analysis of variance repeated measure (n≥4; P<0.05). L-NAME (N(ω)-nitro-L-arginine methyl ester; nitric oxide synthase inhibitor) abolished flow-mediated dilation in arterioles from subjects without CAD, whereas polyethylene glycol-catalase (PEG-catalase; hydrogen peroxide scavenger) had no effect. After exposure to BIBR-1532, arterioles from non-CAD subjects maintained the magnitude of dilation but changed the mediator from nitric oxide to mitochondrial hydrogen peroxide (% max diameter at 100 cm H2O: vehicle 74.6±4.1, L-NAME 37.0±2.0*, PEG-catalase 82.1±2.8; BIBR-1532 69.9±4.0, L-NAME 84.7±2.2, PEG-catalase 36.5±6.9*). Conversely, treatment of microvessels from CAD patients with the telomerase activator AGS 499 converted the PEG-catalase-inhibitable dilation to one mediated by nitric oxide (% max diameter at 100 cm H2O: adipose, AGS 499 78.5±3.9; L-NAME 10.9±17.5*; PEG-catalase 79.2±4.9). Endothelial-independent dilation was not altered with either treatment. CONCLUSIONS We have identified a novel role for telomerase in re-establishing a physiological mechanism of vasodilation in arterioles from subjects with CAD. These findings suggest a new target for reducing the oxidative milieu in the microvasculature of patients with CAD.
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Affiliation(s)
- Andreas M Beyer
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.).
| | - Julie K Freed
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Matthew J Durand
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Michael Riedel
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Karima Ait-Aissa
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Paula Green
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Joseph C Hockenberry
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - R Garret Morgan
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Anthony J Donato
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Refael Peleg
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Mario Gasparri
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Chris K Rokkas
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Janine H Santos
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - Esther Priel
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
| | - David D Gutterman
- From the Department of Medicine, Cardiovascular Center (A.M.B., M.J.D., M.R., K.A.-A., J.C.H., D.D.G.), Department of Physiology (A.M.B., K.A.-A., D.D.G.), Department of Anesthesiology (J.K.F.), Department of Physical Medicine and Rehabilitation (M.J.D.), and Departments of Surgery, Cardiothoracic Surgery (M.G., C.K.R.), Medical College of Wisconsin, Milwaukee; Departments of Pharmacology and Physiology, New Jersey Medical School of Rutgers, Newark (P.G., J.H.S.); Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City (R.G.M., A.J.D.); and Shraga Segal Departments of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (R.P., E.P.)
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Luteolin Inhibits Angiotensin II-Stimulated VSMC Proliferation and Migration through Downregulation of Akt Phosphorylation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:931782. [PMID: 26347796 PMCID: PMC4546982 DOI: 10.1155/2015/931782] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 07/09/2015] [Indexed: 12/15/2022]
Abstract
Luteolin is a naturally occurring flavonoid found in many plants that possesses cardioprotective properties. The purpose of this study was to elucidate the effect of luteolin on vascular smooth muscle cells (VSMCs) proliferation and migration induced by Angiotensin II (Ang II) and to investigate the mechanism(s) of action of this compound. Rat VSMCs were cultured in vitro, and the proliferation and migration of these cells following Ang II stimulation were monitored. Different doses of luteolin were added to VSMC cultures, and the proliferation and migration rate were observed by MTT and Transwell chamber assays, respectively. In addition, the expressions of p-Akt (308), p-Akt (473), and proliferative cell nuclear antigen (PCNA) in VSMCs were monitored by Western blotting. This study demonstrated that luteolin has an inhibitory effect on Ang II-induced VSMC proliferation and migration. Further, the levels of p-Akt (308), p-Akt (473), and PCNA were reduced in VSMCs treated with both Ang II and luteolin compared to VSMCs treated with only Ang II. These findings strongly suggest that luteolin inhibits Ang II-stimulated proliferation and migration of VSMCs, which is partially due to downregulation of the Akt signaling pathway.
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19
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Kusch A, Schmidt M, Gürgen D, Postpieszala D, Catar R, Hegner B, Davidson MM, Mahmoodzadeh S, Dragun D. 17ß-Estradiol regulates mTORC2 sensitivity to rapamycin in adaptive cardiac remodeling. PLoS One 2015; 10:e0123385. [PMID: 25880554 PMCID: PMC4399939 DOI: 10.1371/journal.pone.0123385] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 02/18/2015] [Indexed: 11/19/2022] Open
Abstract
Adaptive cardiac remodeling is characterized by enhanced signaling of mTORC2 downstream kinase Akt. In females, 17ß-estradiol (E2), as well as Akt contribute essentially to sex-related premenopausal cardioprotection. Pharmacologic mTOR targeting with rapamycin is increasingly used for various clinical indications, yet burdened with clinical heterogeneity in therapy responses. The drug inhibits mTORC1 and less-so mTORC2. In male rodents, rapamycin decreases maladaptive cardiac hypertrophy whereas it leads to detrimental dilative cardiomyopathy in females. We hypothesized that mTOR inhibition could interfere with 17β-estradiol (E2)-mediated sexual dimorphism and adaptive cell growth and tested responses in murine female hearts and cultured female cardiomyocytes. Under physiological in vivo conditions, rapamycin compromised mTORC2 function only in female, but not in male murine hearts. In cultured female cardiomyocytes, rapamycin impaired simultaneously IGF-1 induced activation of both mTOR signaling branches, mTORC1 and mTORC2 only in presence of E2. Use of specific estrogen receptor (ER)α- and ERβ-agonists indicated involvement of both estrogen receptors (ER) in rapamycin effects on mTORC1 and mTORC2. Classical feedback mechanisms common in tumour cells with upregulation of PI3K signaling were not involved. E2 effect on Akt-pS473 downregulation by rapamycin was independent of ERK as shown by sequential mTOR and MEK-inhibition. Furthermore, regulatory mTORC2 complex defining component rictor phosphorylation at Ser1235, known to interfere with Akt-substrate binding to mTORC2, was not altered. Functionally, rapamycin significantly reduced trophic effect of E2 on cell size. In addition, cardiomyocytes with reduced Akt-pS473 under rapamycin treatment displayed decreased SERCA2A mRNA and protein expression suggesting negative functional consequences on cardiomyocyte contractility. Rictor silencing confirmed regulation of SERCA2A expression by mTORC2 in E2-cultured female cardiomyocytes. These data highlight a novel modulatory function of E2 on rapamycin effect on mTORC2 in female cardiomyocytes and regulation of SERCA2A expression by mTORC2. Conceivably, rapamycin abrogates the premenopausal “female advantage”.
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Affiliation(s)
- Angelika Kusch
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
- Center for Cardiovascular Research, Charité, Universitätsmedizin Berlin, Berlin, Germany
- * E-mail:
| | - Maria Schmidt
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
| | - Dennis Gürgen
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
- Center for Cardiovascular Research, Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Daniel Postpieszala
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
| | - Rusan Catar
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
- Center for Cardiovascular Research, Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Björn Hegner
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
- Center for Cardiovascular Research, Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Merci M. Davidson
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Shokoufeh Mahmoodzadeh
- Center for Cardiovascular Research, Charité, Universitätsmedizin Berlin, Berlin, Germany
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Duska Dragun
- Department of Nephrology and Intensive Care Medicine, Charité—Campus Virchow Klinikum, Universitätsmedizin Berlin, Berlin, Germany
- Center for Cardiovascular Research, Charité, Universitätsmedizin Berlin, Berlin, Germany
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20
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Roberts DJ, Miyamoto S. Hexokinase II integrates energy metabolism and cellular protection: Akting on mitochondria and TORCing to autophagy. Cell Death Differ 2014; 22:248-57. [PMID: 25323588 DOI: 10.1038/cdd.2014.173] [Citation(s) in RCA: 278] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/11/2014] [Accepted: 09/15/2014] [Indexed: 01/08/2023] Open
Abstract
Accumulating evidence reveals that metabolic and cell survival pathways are closely related, sharing common signaling molecules. Hexokinase catalyzes the phosphorylation of glucose, the rate-limiting first step of glycolysis. Hexokinase II (HK-II) is a predominant isoform in insulin-sensitive tissues such as heart, skeletal muscle, and adipose tissues. It is also upregulated in many types of tumors associated with enhanced aerobic glycolysis in tumor cells, the Warburg effect. In addition to the fundamental role in glycolysis, HK-II is increasingly recognized as a component of a survival signaling nexus. This review summarizes recent advances in understanding the protective role of HK-II, controlling cellular growth, preventing mitochondrial death pathway and enhancing autophagy, with a particular focus on the interaction between HK-II and Akt/mTOR pathway to integrate metabolic status with the control of cell survival.
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Affiliation(s)
- D J Roberts
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - S Miyamoto
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, USA
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21
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Phosphorylated AKT inhibits the apoptosis induced by DRAM-mediated mitophagy in hepatocellular carcinoma by preventing the translocation of DRAM to mitochondria. Cell Death Dis 2014; 5:e1078. [PMID: 24556693 PMCID: PMC3944266 DOI: 10.1038/cddis.2014.51] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 12/14/2013] [Accepted: 12/23/2013] [Indexed: 12/15/2022]
Abstract
Increasing autophagy is beneficial for curing hepatocellular carcinoma (HCC). Damage-regulated autophagy modulator (DRAM) was recently reported to induce apoptosis by mediating autophagy. However, the effects of DRAM-mediated autophagy on apoptosis in HCC cells remain unclear. In this study, normal hepatocytes (7702) and HCC cell lines (HepG2, Hep3B and Huh7) were starved for 48 h. Starvation induced apoptosis and autophagy in all cell lines. We determined that starvation also induced DRAM expression and DRAM-mediated autophagy in both normal hepatocytes and HCC cells. However, DRAM-mediated autophagy was involved in apoptosis in normal hepatocytes but not in HCC cells, suggesting that DRAM-mediated autophagy fails to induce apoptosis in hepatoma in response to starvation. Immunoblot and immunofluorescence assays demonstrated that DRAM translocated to mitochondria and induced mitophagy, which led to apoptosis in 7702 cells. In HCC cells, starvation also activated the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which blocks the translocation of DRAM to mitochondria through the binding of p-AKT to DRAM in the cytoplasm. Inactivation of the PI3K/AKT pathway rescued DRAM translocation to mitochondria; subsequently, mitochondrial DRAM induced apoptosis in HCC cells by mediating mitophagy. Our findings open new avenues for the investigation of the mechanisms of DRAM-mediated autophagy and suggest that promoting DRAM-mediated autophagy together with PI3K/AKT inhibition might be more effective for autophagy-based therapy in hepatoma.
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22
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Hu S, Yan G, Xu H, He W, Liu Z, Ma G. Hypoxic preconditioning increases survival of cardiac progenitor cells via the pim-1 kinase-mediated anti-apoptotic effect. Circ J 2014; 78:724-31. [PMID: 24401608 DOI: 10.1253/circj.cj-13-0841] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Stem cells transplanted to the ischemic myocardium usually encounter massive cell death within a few days after transplantation, and hypoxic preconditioning (HPC) is currently used as a strategy to prepare stem cells for increased survival and engraftment in the heart. The purpose of this study is to determine whether Pim-1 kinase mediates any beneficial effects of HPC for human cardiac progenitor cells (CPCs). METHODS AND RESULTS Human CPCs were isolated from an adult heart auricle and were purified by magnetic-activated cell sorting using c-kit magnetic beads; they were hypoxic preconditioned for 6h. Both Pim-1 and p-Akt were determined. CPCs were assigned to one of the following groups: (1) control (without HPC); (2) HPC; or (3) HPC+I (Pim-1 inhibitor). HPC can promote the survival of CPCs. HPC enhances the expression of Pim-1 kinase in a time-dependent manner, which causes a reduction of proapoptotic elements (cytochrome c and cleaved caspase-3) and the preservation/modulation of important components of the mitochondria (Bcl-2, Bcl-XL and p-Bad), and attenuates mitochondrial damages. All of these protective effects were blocked by a Pim-1 inhibitor. CONCLUSIONS Pim-1 plays a pivotal role in the protective effect of HPC for CPCs, and the promotion of the expression of Pim-1 in CPCs can as serve part of molecular therapeutic interventional strategies in the treatment of cardiomyopathy damage by blunting CPC death.
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Affiliation(s)
- Shengda Hu
- Department of Cardiology, Zhongda Hospital, Medical School, Southeast University
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23
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Lu X, Costantini T, Lopez NE, Wolf PL, Hageny AM, Putnam J, Eliceiri B, Coimbra R. Vagal nerve stimulation protects cardiac injury by attenuating mitochondrial dysfunction in a murine burn injury model. J Cell Mol Med 2013; 17:664-71. [PMID: 23577721 PMCID: PMC3822819 DOI: 10.1111/jcmm.12049] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 02/07/2013] [Indexed: 01/29/2023] Open
Abstract
Mitochondria play a central role in the integration and execution of a wide variety of apoptotic signals. In the present study, we examined the deleterious effects of burn injury on heart tissue. We explored the effects of vagal nerve stimulation (VNS) on cardiac injury in a murine burn injury model, with a focus on the protective effect of VNS on mitochondrial dysfunction in heart tissue. Mice were subjected to a 30% total body surface area, full-thickness steam burn followed by right cervical VNS for 10 min. and compared to burn alone. A separate group of mice were treated with the M3-muscarinic acetylcholine receptor (M3-AchR) antagonist 4-DAMP or phosphatidylinositol 3 Kinase (PI3K) inhibitor LY294002 prior to burn and VNS. Heart tissue samples were collected at 6 and 24 hrs after injury to measure changes in apoptotic signalling pathways. Burn injury caused significant cardiac pathological changes, cardiomyocyte apoptosis, mitochondrial swelling and decrease in myocardial ATP content at 6 and 24 hrs after injury. These changes were significantly attenuated by VNS. VNS inhibited release of pro-apoptotic protein cytochrome C and apoptosis-inducing factor from mitochondria to cytosol by increasing the expression of Bcl-2, and the phosphorylation level of Bad (pBad136) and Akt (pAkt308). These protective changes were blocked by 4-DAMP or LY294002. We demonstrated that VNS protected against burn injury–induced cardiac injury by attenuating mitochondria dysfunction, likely through the M3-AchR and the PI3K/Akt signalling pathways.
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Affiliation(s)
- Xiaojiong Lu
- Division of Trauma, Surgical Critical Care and Burns, Department of Surgery, University of California San Diego Health Sciences, San Diego, CA 92103, USA
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24
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Singh M, Martinez AR, Govindaraju S, Lee BS. HuR inhibits apoptosis by amplifying Akt signaling through a positive feedback loop. J Cell Physiol 2012; 228:182-9. [PMID: 22674407 DOI: 10.1002/jcp.24120] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Human antigen R (HuR) is a post-transcriptional regulator of gene expression that plays a key role in stabilizing mRNAs during cellular stress, leading to enhanced survival. HuR expression is tightly regulated through multiple transcription and post-transcriptional controls. Although HuR is known to stabilize a subset of mRNAs involved in cell survival, its role in the survival pathway of PI3-kinase/Akt signaling is unclear. Here, we show that in renal proximal tubule cells, HuR performs a central role in cell survival by amplifying Akt signaling in a positive feedback loop. Key to this feedback loop is HuR-mediated stabilization of mRNA encoding Grb10, an adaptor protein whose expression is critical for Akt activation. Stimulation of Akt by interaction with Grb10 then activates NF-κB, which further enhances HuR mRNA and protein expression. This feedback loop is active in unstressed cells, but its effects are increased during stress. Therefore, this study demonstrates a central role for HuR in Akt signaling and reveals a mechanism by which modest changes in HuR levels below or above normal may be amplified, potentially resulting in cell death or cellular transformation.
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Affiliation(s)
- Mamata Singh
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio, USA
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25
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Ablation of the cardiac-specific gene leucine-rich repeat containing 10 (Lrrc10) results in dilated cardiomyopathy. PLoS One 2012; 7:e51621. [PMID: 23236519 PMCID: PMC3517560 DOI: 10.1371/journal.pone.0051621] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 11/02/2012] [Indexed: 01/06/2023] Open
Abstract
Leucine-rich repeat containing 10 (LRRC10) is a cardiac-specific protein exclusively expressed in embryonic and adult cardiomyocytes. However, the role of LRRC10 in mammalian cardiac physiology remains unknown. To determine if LRRC10 is critical for cardiac function, Lrrc10-null (Lrrc10−/−) mice were analyzed. Lrrc10−/− mice exhibit prenatal systolic dysfunction and dilated cardiomyopathy in postnatal life. Importantly, Lrrc10−/− mice have diminished cardiac performance in utero, prior to ventricular dilation observed in young adults. We demonstrate that LRRC10 endogenously interacts with α-actinin and α-actin in the heart and all actin isoforms in vitro. Gene expression profiling of embryonic Lrrc10−/− hearts identified pathways and transcripts involved in regulation of the actin cytoskeleton to be significantly upregulated, implicating dysregulation of the actin cytoskeleton as an early defective molecular signal in the absence of LRRC10. In contrast, microarray analyses of adult Lrrc10−/− hearts identified upregulation of oxidative phosphorylation and cardiac muscle contraction pathways during the progression of dilated cardiomyopathy. Analyses of hypertrophic signal transduction pathways indicate increased active forms of Akt and PKCε in adult Lrrc10−/− hearts. Taken together, our data demonstrate that LRRC10 is essential for proper mammalian cardiac function. We identify Lrrc10 as a novel dilated cardiomyopathy candidate gene and the Lrrc10−/− mouse model as a unique system to investigate pediatric cardiomyopathy.
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26
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Chronic treatment with LY294002, an inhibitor of phosphatidylinositol 3-kinase, attenuates ischemia/reperfusion-induced cardiac dysfunction in normotensive and hypertensive diabetic animals. Mol Cell Biochem 2012; 373:259-64. [PMID: 23124851 DOI: 10.1007/s11010-012-1497-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 10/25/2012] [Indexed: 10/27/2022]
Abstract
Diabetes is associated with increased incidence of cardiovascular disease. Mechanisms that contribute to development of diabetic cardiopathy are not well understood. Phosphatidylinositol 3-kinase (PI3K) is a family of protein kinases that play an important role in regulation of cardiac function. It has been shown that inhibition of certain PI3K enzymes may produce cardiovascular protection. The aim of the present study was to determine whether chronic treatment with LY294002, an inhibitor of PI3K, can attenuate diabetes-induced cardiac dysfunction in isolated hearts obtained from normotensive and hypertensive rats. Recovery of cardiac function after 40 min of global ischemia and 30 min of reperfusion, measured as left ventricular developed pressure, left ventricular end-diastolic pressure, coronary flow and coronary vascular resistance, was worse in hearts obtained from diabetic and/or hypertensive animals compared to their respective controls. Treatment with LY294002 (1.2 mg/kg/day) for 4 weeks significantly prevented diabetes-induced cardiac dysfunction in both normotensive and hypertensive rats. Treatment with LY294002 did not significantly alter blood pressure or blood glucose levels. These results suggest that inhibition of PI3K signaling pathways can prevent ischemia/reperfusion-induced cardiac dysfunction in normotensive and hypertensive rats without correcting hyperglycemia or high blood pressure.
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27
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Luo L, Kaur Kumar J, Clément MV. Redox control of cytosolic Akt phosphorylation in PTEN null cells. Free Radic Biol Med 2012; 53:1697-707. [PMID: 22940494 DOI: 10.1016/j.freeradbiomed.2012.08.566] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 07/25/2012] [Accepted: 08/13/2012] [Indexed: 01/01/2023]
Abstract
This article demonstrates a role for intracellular reactive oxygen species in the hyperphosphorylation of Akt in cells that have lost the expression of the tumor suppressor PTEN. Using mouse embryonic fibroblasts in which the expression of PTEN was knocked out, we show that a decrease in intracellular superoxide anion resulted in a rapid dephosphorylation of Akt at Thr308 followed by Ser473. Whereas dephosphorylation was detected in the cytosolic pool of Akt, phosphorylation of the membrane pool of the kinase remained unaffected. Dephosphorylation of cytosolic Akt was attributed to an increase in the interaction between Akt and the catalytic subunit of the protein phosphatase PP2A, which correlated with an increase in the amount of the oxidized versus the reduced form of the kinase. These results were corroborated in the PTEN knockout prostate cancer cell line LNCaP and in the melanoma cell line M14 stably transfected with a constitutively active form of Rac1.
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Affiliation(s)
- Le Luo
- Yong Loo Lin School of Medicine, Department of Biochemistry, National University of Singapore, Singapore
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28
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Avila J, Gregory OG, Su D, Deeter TA, Chen S, Silva-Sanchez C, Xu S, Martin GB, Devarenne TP. The β-subunit of the SnRK1 complex is phosphorylated by the plant cell death suppressor Adi3. PLANT PHYSIOLOGY 2012; 159:1277-90. [PMID: 22573803 PMCID: PMC3387709 DOI: 10.1104/pp.112.198432] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/08/2012] [Indexed: 05/17/2023]
Abstract
The protein kinase AvrPto-dependent Pto-interacting protein3 (Adi3) is a known suppressor of cell death, and loss of its function has been correlated with cell death induction during the tomato (Solanum lycopersicum) resistance response to its pathogen Pseudomonas syringae pv tomato. However, Adi3 downstream interactors that may play a role in cell death regulation have not been identified. We used a yeast two-hybrid screen to identify the plant SnRK1 (for Sucrose non-Fermenting-1-Related Protein Kinase1) protein as an Adi3-interacting protein. SnRK1 functions as a regulator of carbon metabolism and responses to biotic and abiotic stresses. SnRK1 exists in a heterotrimeric complex with a catalytic α-subunit (SnRK1), a substrate-interacting β-subunit, and a regulatory γ-subunit. Here, we show that Adi3 interacts with, but does not phosphorylate, the SnRK1 α-subunit. The ability of Adi3 to phosphorylate the four identified tomato β-subunits was also examined, and it was found that only the Galactose Metabolism83 (Gal83) β-subunit was phosphorylated by Adi3. This phosphorylation site on Gal83 was identified as serine-26 using a mutational approach and mass spectrometry. In vivo expression of Gal83 indicates that it contains multiple phosphorylation sites, one of which is serine-26. An active SnRK1 complex containing Gal83 as the β-subunit and sucrose nonfermenting4 as the γ-subunit was constructed to examine functional aspects of the Adi3 interaction with SnRK1 and Gal83. These assays revealed that Adi3 is capable of suppressing the kinase activity of the SnRK1 complex through Gal83 phosphorylation plus the interaction with SnRK1 and suggested that this function may be related to the cell death suppression activity of Adi3.
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Affiliation(s)
- Julian Avila
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Oliver G. Gregory
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Dongyin Su
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Taunya A. Deeter
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Sixue Chen
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Cecilia Silva-Sanchez
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Shouling Xu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Gregory B. Martin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
| | - Timothy P. Devarenne
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843 (J.A., D.S., T.A.D., T.P.D.); Department of Biology, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida 32610 (S.C., C.S.-S.); Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (S.X.); Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853 (G.B.M.); and Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (O.G.G., G.B.M.)
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Leander K, Gigante B, Silveira A, Vikström M, Hamsten A, Högberg J. NAMPT (visfatin) and AKT1 genetic variants associate with myocardial infarction. Clin Chim Acta 2012; 413:727-32. [PMID: 22251423 DOI: 10.1016/j.cca.2012.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 12/31/2011] [Accepted: 01/03/2012] [Indexed: 01/24/2023]
Abstract
BACKGROUND High plasma levels of the adipokine NAMPT (or visfatin) have been associated with cardiovascular disease. However experimental data suggest that NAMPT, via Akt signaling, protects the myocardium against hypoxic insults. We studied whether the NAMPT rs1319501, AKT1 rs3730358, p53 rs1042522, Mdm2 rs2279744 or eNOS rs1799983 SNP:s linked to NAMPT and Akt signaling associate with risk of myocardial infarction (MI). METHODS Cases were 828 men and 346 women aged 45-70 who had suffered a first MI. Control individuals, 1062 men and 513 women, were randomly chosen from the study base. We employed unconditional logistic regression analysis. RESULTS The rs1319501 minor allele associated with MI among women aged 45-60; odds ratio (OR) under a recessive model of inheritance: 2.96 (95% confidence interval [CI] 1.06-8.29). Replication analysis in an independent material yielded OR point estimates in the same direction. The rs3730358 minor allele associated with low MI risk in men aged 45-60 (OR dominant model: 0.72, 95% CI 0.53-0.97), an association completely attenuated by adjusting for inflammatory markers. CONCLUSIONS The NAMPT rs1319501 minor allele associates with increased MI risk in young women. In young men a protective effect of the AKT1 rs3730358 minor allele was suggested, possibly related to an attenuated inflammation.
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Affiliation(s)
- Karin Leander
- Division of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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30
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Lang Y, Chen D, Li D, Zhu M, Xu T, Zhang T, Qian W, Luo Y. Luteolin inhibited hydrogen peroxide-induced vascular smooth muscle cells proliferation and migration by suppressing the Src and Akt signalling pathways. J Pharm Pharmacol 2011; 64:597-603. [PMID: 22420665 DOI: 10.1111/j.2042-7158.2011.01438.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract
Objectives
Luteolin is a naturally occurring flavonoid found in many vegetables, fruits and medicinal plants. The migration and proliferation of vascular smooth muscle cells (VSMCs) are the critical pathological processes in various cardiovascular diseases, such as atherosclerosis. In this study, we investigated the effect of luteolin and its latent mechanism on the proliferation and migration of VSMCs stimulated by hydrogen peroxide (H2O2).
Methods
VSMC proliferation and cell viability was assayed using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) method or by cell counting, and H2O2-elicited migration of VSMCs was measured using a transwell migration assay. The phosphorylation levels of Src, 3-phosphoinositide-dependent kinase 1 (PDK1) and Akt (protein kinase B) were analysed by immunoblotting.
Key findings
This study demonstrated that luteolin showed a particularly inhibitory effect on H2O2-elicited VSMC proliferation and migration. In previous research, we originally explored the function of luteolin in blocking H2O2-triggered Src and Akt signalling pathways. The activation of Src, PDK1, Akt (308), Akt (473) in the luteolin-treated group was significantly lower than that seen in the H2O2 group.
Conclusions
These findings strongly suggested that luteolin suppresses H2O2-directed migration and proliferation in VSMCs partially due to down-regulation of the Akt and Src signalling pathways, which are important participants in the processes of migration and proliferation of VSMCs.
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Affiliation(s)
- Yasong Lang
- Institute of Cardiovascular Disease Research, Xuzhou Medical College, Xuzhou, China
| | - Dan Chen
- Institute of Cardiovascular Disease Research, Xuzhou Medical College, Xuzhou, China
| | - Dongye Li
- Institute of Cardiovascular Disease Research, Xuzhou Medical College, Xuzhou, China
| | - Manyi Zhu
- Institute of Cardiovascular Disease Research, Xuzhou Medical College, Xuzhou, China
| | - Tongda Xu
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, China
| | - Tian Zhang
- Institute of Cardiovascular Disease Research, Xuzhou Medical College, Xuzhou, China
| | - Wenhao Qian
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, China
| | - Yuanyuan Luo
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, China
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31
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Vascular effects of glycoprotein130 ligands--part I: pathophysiological role. Vascul Pharmacol 2011; 56:34-46. [PMID: 22197898 DOI: 10.1016/j.vph.2011.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 12/02/2011] [Accepted: 12/09/2011] [Indexed: 12/25/2022]
Abstract
The vessel wall is no longer considered as only an anatomical barrier for blood cells but is recognized as an active endocrine organ. Dysfunction of the vessel wall occurs in various disease processes including atherosclerosis, hypertension, peripheral artery disease, aneurysms, and transplant and diabetic vasculopathies. Different cytokines were shown to modulate the behavior of the cells, which constitute the vessel wall such as immune cells, endothelial cells and smooth muscle cells. Glycoprotein 130 (gp130) is a common cytokine receptor that controls the activity of a group of cytokines, namely, interleukin (IL)-6, oncostatin M (OSM), IL-11, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), IL-27, and neuropoietin (NP). Gp130 and associated cytokines have abundantly diverse functions. Part I of this review focuses on the pathophysiological functions of gp130 ligands. We specifically describe vascular effects of these molecules and discuss the respective underlying molecular and cellular mechanisms.
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32
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Vaniotis G, Allen BG, Hébert TE. Nuclear GPCRs in cardiomyocytes: an insider's view of β-adrenergic receptor signaling. Am J Physiol Heart Circ Physiol 2011; 301:H1754-64. [PMID: 21890692 DOI: 10.1152/ajpheart.00657.2011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In recent years, we have come to appreciate the complexity of G protein-coupled receptor signaling in general and β-adrenergic receptor (β-AR) signaling in particular. Starting originally from three β-AR subtypes expressed in cardiomyocytes with relatively simple, linear signaling cascades, it is now clear that there are large receptor-based networks which provide a rich and diverse set of responses depending on their complement of signaling partners and the physiological state. More recently, it has become clear that subcellular localization of these signaling complexes also enriches the diversity of phenotypic outcomes. Here, we review our understanding of the signaling repertoire controlled by nuclear β-AR subtypes as well our understanding of the novel roles for G proteins themselves in the nucleus, with a special focus, where possible, on their effects in cardiomyocytes. Finally, we discuss the potential pathological implications of alterations in nuclear β-AR signaling.
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Khan SH, Ahmad F, Ahmad N, Flynn DC, Kumar R. Protein-protein interactions: principles, techniques, and their potential role in new drug development. J Biomol Struct Dyn 2011; 28:929-38. [PMID: 21469753 DOI: 10.1080/07391102.2011.10508619] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
A vast network of genes is inter-linked through protein-protein interactions and is critical component of almost every biological process under physiological conditions. Any disruption of the biologically essential network leads to pathological conditions resulting into related diseases. Therefore, proper understanding of biological functions warrants a comprehensive knowledge of protein-protein interactions and the molecular mechanisms that govern such processes. The importance of protein-protein interaction process is highlighted by the fact that a number of powerful techniques/methods have been developed to understand how such interactions take place under various physiological and pathological conditions. Many of the key protein-protein interactions are known to participate in disease-associated signaling pathways, and represent novel targets for therapeutic intervention. Thus, controlling protein-protein interactions offers a rich dividend for the discovery of new drug targets. Availability of various tools to study and the knowledge of human genome have put us in a unique position to understand highly complex biological network, and the mechanisms involved therein. In this review article, we have summarized protein-protein interaction networks, techniques/methods of their binding/kinetic parameters, and the role of these interactions in the development of potential tools for drug designing.
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Affiliation(s)
- Shagufta H Khan
- Department of Basic Sciences, The Commonwealth Medical College, 501 Madison Avenue, Scranton, PA 18510, USA
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Abstract
PURPOSE OF REVIEW Inflammation is a key component in cardiovascular disease. Controlling inflammatory events and their subsequent processes holds the potential for novel therapeutic treatment options. Cytokines are the propagators of inflammation. In this review we will discuss important cytokines including IL-6, TNF-α, MCP-1, fractalkine, M-CSF and GDF-15, and their effect on cardiac outcome. RECENT FINDINGS Recent studies have shed light on the role of IL-6 in cardiovascular disease. Long-term IL-6 levels are highly associated with coronary heart disease. Molecular studies indicate that a permanent prolongation of STAT signaling in cardiac myocytes might be a potential reason for the detrimental effects of IL-6. TNF-α was long considered to have detrimental effects on myocardial function but recent studies show cardioprotective mechanisms for TNF-α. Macrophage modulating cytokines emerge as interesting molecular targets to treat cardiovascular disease. Especially, the two different subtypes of monocytes, a pro-inflammatory and a reparative subset, and their different chemotactic properties might be possible drug targets. Finally, we discuss GDF-15, which emerges as a novel biomarker in cardiovascular disease reflecting information from several pathological pathways. SUMMARY Cytokines are the main proximal mediators of inflammation and hold the potential of being good molecular targets for novel treatment regimes. Cytokines might be valuable biomarkers, adding information about the pathologic pathways in cardiovascular disease.
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STAT3α interacts with nuclear GSK3beta and cytoplasmic RISK pathway and stabilizes rhythm in the anoxic-reoxygenated embryonic heart. Basic Res Cardiol 2011; 106:355-69. [DOI: 10.1007/s00395-011-0152-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 12/23/2010] [Accepted: 01/13/2011] [Indexed: 01/18/2023]
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36
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Fischer KM, Cottage CT, Konstandin MH, Völkers M, Khan M, Sussman MA. Pim-1 kinase inhibits pathological injury by promoting cardioprotective signaling. J Mol Cell Cardiol 2011; 51:554-8. [PMID: 21255581 DOI: 10.1016/j.yjmcc.2011.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/06/2011] [Accepted: 01/10/2011] [Indexed: 12/19/2022]
Abstract
Stem cells mediate tissue repair throughout the lifespan of an organism. However, the ability of stem cells to mitigate catastrophic damage, such as that sustained after major myocardial infarction is inadequate to rebuild the heart and restore functional capacity. However, capitalizing on the ability of these cells to attenuate damage in the myocardium, various maneuvers that enhance repair mechanisms to improve cardiac structure and function after injury are being investigated. These studies have led to discovery of various factors that mediate cardioprotection and enhance endogenous repair by 1) salvaging surviving myocardium, 2) promoting homing of stem cells and 3) increasing survival and proliferation of stem cell populations at the site of injury. Herein we report upon a downstream target of Akt kinase, named Pim-1, which promotes cardioprotective signaling and enhances cardiac structure and function after pathological injury. The compilation of studies presented here supports use of Pim-1 to enhance long-term myocardial repair after pathological damage. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."
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Affiliation(s)
- Kimberlee M Fischer
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
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Vaughn LK, Denning G, Stuhr KL, de Wit H, Hill MN, Hillard CJ. Endocannabinoid signalling: has it got rhythm? Br J Pharmacol 2010; 160:530-43. [PMID: 20590563 DOI: 10.1111/j.1476-5381.2010.00790.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Endogenous cannabinoid signalling is widespread throughout the body, and considerable evidence supports its modulatory role in many fundamental physiological processes. The daily and seasonal cycles of the relationship of the earth and sun profoundly affect the terrestrial environment. Terrestrial species have adapted to these cycles in many ways, most well studied are circadian rhythms and hibernation. The purpose of this review was to examine literature support for three hypotheses: (i) endocannabinoid signalling exhibits brain region-specific circadian rhythms; (ii) endocannabinoid signalling modulates the rhythm of circadian processes in mammals; and (iii) changes in endocannabinoid signalling contribute to the state of hibernation. The results of two novel studies are presented. First, we report the results of a study of healthy humans demonstrating that plasma concentrations of the endocannabinoid, N-arachidonylethanolamine (anandamide), exhibit a circadian rhythm. Concentrations of anandamide are threefold higher at wakening than immediately before sleep, a relationship that is dysregulated by sleep deprivation. Second, we investigated differences in endocannabinoids and congeners in plasma from Marmota monax obtained in the summer and during the torpor state of hibernation. We report that 2-arachidonoylglycerol is below detection in M. monax plasma and that concentrations of anandamide are not different. However, plasma concentrations of the anorexigenic lipid oleoylethanolamide were significantly lower in hibernation, while the concentrations of palmitoylethanolamide and 2-oleoylglycerol were significantly greater in hibernation. We conclude that available data support a bidirectional relationship between endocannabinoid signalling and circadian processes, and investigation of the contribution of endocannabinoid signalling to the dramatic physiological changes that occur during hibernation is warranted.
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Affiliation(s)
- Linda K Vaughn
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
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Peart JN, Hoe LES, Gross GJ, Headrick JP. Sustained ligand-activated preconditioning via δ-opioid receptors. J Pharmacol Exp Ther 2010; 336:274-81. [PMID: 20947639 DOI: 10.1124/jpet.110.172593] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously described novel cardioprotection in response to sustained morphine exposure, efficacious in young to aged myocardium and mechanistically distinct from conventional opioid or preconditioning (PC) responses. We further investigate opioid-dependent sustained ligand-activated preconditioning (SLP), assessing duration of protection, opioid receptor involvement, additivity with conventional responses, and signaling underlying preischemic induction of the phenotype. Male C57BL/6 mice were treated with morphine (75-mg subcutaneous pellet) for 5 days followed by morphine-free periods (0, 3, 5, or 7 days) before ex vivo assessment of myocardial tolerance to 25-min ischemia/45-min reperfusion. SLP substantially reduced infarction (by ∼50%) and postischemic contractile dysfunction (eliminating contracture, doubling force development). Cardioprotection persisted for 5 to 7 days after treatment. SLP was induced specifically by δ-receptor and not κ- or μ-opioid receptor agonism, was eliminated by δ-receptor and nonselective antagonism, and was additive with adenosinergic but not acute morphine- or PC-triggered protection. Cotreatment during preischemic morphine exposure with the phosphoinositide-3 kinase (PI3K) inhibitor wortmannin, but not the protein kinase A (PKA) inhibitor myristoylated PKI-(14-22)-amide, prevented induction of SLP. This was consistent with shifts in total and phospho-Akt during the induction period. In summary, data reveal that SLP triggers sustained protection from ischemia for up to 7 days after stimulus, is δ-opioid receptor mediated, is induced in a PI3K-dependent/PKA-independent manner, and augments adenosinergic protection. Mechanisms underlying SLP may be useful targets for manipulation of ischemic tolerance in young or aged myocardium.
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Affiliation(s)
- Jason N Peart
- Heart Foundation Research Centre, Griffith University, Southport, Australia.
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Kerner J, Lee K, Hoppel CL. Post-translational modifications of mitochondrial outer membrane proteins. Free Radic Res 2010; 45:16-28. [DOI: 10.3109/10715762.2010.515218] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Vaniotis G, Del Duca D, Trieu P, Rohlicek CV, Hébert TE, Allen BG. Nuclear β-adrenergic receptors modulate gene expression in adult rat heart. Cell Signal 2010; 23:89-98. [PMID: 20732414 DOI: 10.1016/j.cellsig.2010.08.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 08/05/2010] [Accepted: 08/16/2010] [Indexed: 01/26/2023]
Abstract
Both β(1)- and β(3)-adrenergic receptors (β(1)ARs and β(3)ARs) are present on nuclear membranes in adult ventricular myocytes. These nuclear-localized receptors are functional with respect to ligand binding and effector activation. In isolated cardiac nuclei, the non-selective βAR agonist isoproterenol stimulated de novo RNA synthesis measured using assays of transcription initiation (Boivin et al., 2006 Cardiovasc Res. 71:69-78). In contrast, stimulation of endothelin receptors, another G protein-coupled receptor (GPCR) that localizes to the nuclear membrane, resulted in decreased RNA synthesis. To investigate the signalling pathway(s) involved in GPCR-mediated regulation of RNA synthesis, nuclei were isolated from intact adult rat hearts and treated with receptor agonists in the presence or absence of inhibitors of different mitogen-activated protein kinase (MAPK) and PI3K/PKB pathways. Components of p38, JNK, and ERK1/2 MAP kinase cascades as well as PKB were detected in nuclear preparations. Inhibition of PKB with triciribine, in the presence of isoproterenol, converted the activation of the βAR from stimulatory to inhibitory with regards to RNA synthesis, while ERK1/2, JNK and p38 inhibition reduced both basal and isoproterenol-stimulated activity. Analysis by qPCR indicated an increase in the expression of 18S rRNA following isoproterenol treatment and a decrease in NFκB mRNA. Further qPCR experiments revealed that isoproterenol treatment also reduced the expression of several other genes involved in the activation of NFκB, while ERK1/2 and PKB inhibition substantially reversed this effect. Our results suggest that GPCRs on the nuclear membrane regulate nuclear functions such as gene expression and this process is modulated by activation/inhibition of downstream protein kinases within the nucleus.
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Affiliation(s)
- George Vaniotis
- Department of Biochemistry, Université de Montréal, Montréal, Québec, Canada
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41
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Ek-Ramos MJ, Avila J, Cheng C, Martin GB, Devarenne TP. The T-loop extension of the tomato protein kinase AvrPto-dependent Pto-interacting protein 3 (Adi3) directs nuclear localization for suppression of plant cell death. J Biol Chem 2010; 285:17584-94. [PMID: 20371603 PMCID: PMC2878523 DOI: 10.1074/jbc.m110.117416] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 04/05/2010] [Indexed: 02/02/2023] Open
Abstract
In tomato (Solanum lycopersicum), resistance to Pseudomonas syringae pv. tomato is elicited by the interaction of the host Pto kinase with the pathogen effector protein AvrPto, which leads to various immune responses including localized cell death termed the hypersensitive response. The AGC kinase Adi3 functions to suppress host cell death and interacts with Pto only in the presence of AvrPto. The cell death suppression (CDS) activity of Adi3 requires phosphorylation by 3-phosphoinositide-dependent protein kinase 1 (Pdk1) and loss of Adi3 function is associated with the hypersensitive response cell death initiated by the Pto/AvrPto interaction. Here we studied the relationship between Adi3 cellular localization and its CDS activity. Adi3 is a nuclear-localized protein, and this localization is dictated by a nuclear localization signal found in the Adi3 T-loop extension, an approximately 80 amino acid insertion into the T-loop, or activation loop, which is phosphorylated for kinase activation. Nuclear localization of Adi3 is required for its CDS activity and loss of nuclear localization causes elimination of Adi3 CDS activity and induction of cell death. This nuclear localization of Adi3 is dependent on Ser-539 phosphorylation by Pdk1 and non-nuclear Adi3 is found in punctate structures throughout the cell. Our data support a model in which Pdk1 phosphorylation of Adi3 directs nuclear localization for CDS and that disruption of Adi3 nuclear localization may be a mechanism for induction of cell death such as that during the Pto/AvrPto interaction.
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Affiliation(s)
- María J. Ek-Ramos
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Julian Avila
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Cheng Cheng
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Gregory B. Martin
- the Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, and
- the Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853
| | - Timothy P. Devarenne
- From the Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
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42
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Borillo GA, Mason M, Quijada P, Völkers M, Cottage C, McGregor M, Din S, Fischer K, Gude N, Avitable D, Barlow S, Gustafsson AB, Glembotski C, Gottlieb RA, Brown JH, Sussman MA. Pim-1 kinase protects mitochondrial integrity in cardiomyocytes. Circ Res 2010; 106:1265-74. [PMID: 20203306 PMCID: PMC2864233 DOI: 10.1161/circresaha.109.212035] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
RATIONALE Cardioprotective signaling mediates antiapoptotic actions through multiple mechanisms including maintenance of mitochondrial integrity. Pim-1 kinase is an essential downstream effector of AKT-mediated cardioprotection but the mechanistic basis for maintenance of mitochondrial integrity by Pim-1 remains unexplored. This study details antiapoptotic actions responsible for enhanced cell survival in cardiomyocytes with elevated Pim-1 activity. OBJECTIVE The purpose of this study is to demonstrate that the cardioprotective kinase Pim-1 acts to inhibit cell death by preserving mitochondrial integrity in cardiomyocytes. METHODS AND RESULTS A combination of biochemical, molecular, and microscopic analyses demonstrate beneficial effects of Pim-1 on mitochondrial integrity. Pim-1 protein level increases in the mitochondrial fraction with a corresponding decrease in the cytosolic fraction of myocardial lysates from hearts subjected to 30 minutes of ischemia followed by 30 minutes of reperfusion. Cardiac-specific overexpression of Pim-1 results in higher levels of antiapoptotic Bcl-X(L) and Bcl-2 compared to samples from normal hearts. In response to oxidative stress challenge, Pim-1 preserves the inner mitochondrial membrane potential. Ultrastructure of the mitochondria is maintained by Pim-1 activity, which prevents swelling induced by calcium overload. Finally, mitochondria isolated from hearts created with cardiac-specific overexpression of Pim-1 show inhibition of cytochrome c release triggered by a truncated form of proapoptotic Bid. CONCLUSION Cardioprotective action of Pim-1 kinase includes preservation of mitochondrial integrity during cardiomyopathic challenge conditions, thereby raising the potential for Pim-1 kinase activation as a therapeutic interventional approach to inhibit cell death by antagonizing proapoptotic Bcl-2 family members that regulate the intrinsic apoptotic pathway.
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MESH Headings
- Animals
- Animals, Newborn
- Apoptosis
- BH3 Interacting Domain Death Agonist Protein/metabolism
- Cell Survival
- Cells, Cultured
- Cytochromes c/metabolism
- Disease Models, Animal
- Humans
- Membrane Potential, Mitochondrial
- Mice
- Mice, Transgenic
- Mitochondria, Heart/enzymology
- Mitochondria, Heart/ultrastructure
- Mitochondrial Swelling
- Myocardial Reperfusion Injury/enzymology
- Myocardial Reperfusion Injury/genetics
- Myocardial Reperfusion Injury/pathology
- Myocardial Reperfusion Injury/prevention & control
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/ultrastructure
- Oxidative Stress
- Protein Transport
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Proto-Oncogene Proteins c-pim-1/genetics
- Proto-Oncogene Proteins c-pim-1/metabolism
- Rats
- Rats, Sprague-Dawley
- Recombinant Fusion Proteins/metabolism
- Time Factors
- Transfection
- bcl-X Protein/metabolism
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Affiliation(s)
- Gwynngelle A. Borillo
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Matt Mason
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Pearl Quijada
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Mirko Völkers
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Christopher Cottage
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Michael McGregor
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Shabana Din
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Kimberlee Fischer
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Natalie Gude
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Daniele Avitable
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Steven Barlow
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Asa B. Gustafsson
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | | | - Roberta A. Gottlieb
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, CA 92093-0636, USA
| | - Mark A. Sussman
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
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Wang X, Zhao T, Huang W, Wang T, Qian J, Xu M, Kranias EG, Wang Y, Fan GC. Hsp20-engineered mesenchymal stem cells are resistant to oxidative stress via enhanced activation of Akt and increased secretion of growth factors. Stem Cells 2010; 27:3021-31. [PMID: 19816949 DOI: 10.1002/stem.230] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Although heat-shock preconditioning has been shown to promote cell survival under oxidative stress, the nature of heat-shock response from different cells is variable and complex. Therefore, it remains unclear whether mesenchymal stem cells (MSCs) modified with a single heat-shock protein (Hsp) gene are effective in the repair of a damaged heart. In this study, we genetically engineered rat MSCs with Hsp20 gene (Hsp20-MSCs) and examined cell survival, revascularization, and functional improvement in rat left anterior descending ligation (LAD) model via intracardial injection. We observed that overexpression of Hsp20 protected MSCs against cell death triggered by oxidative stress in vitro. The survival of Hsp20-MSCs was increased by approximately twofold by day 4 after transplantation into the infarcted heart, compared with that of vector-MSCs. Furthermore, Hsp20-MSCs improved cardiac function of infarcted myocardium as compared with vector-MSCs, accompanied by reduction of fibrosis and increase in the vascular density. The mechanisms contributing to the beneficial effects of Hsp20 were associated with enhanced Akt activation and increased secretion of growth factors (VEGF, FGF-2, and IGF-1). The paracrine action of Hsp20-MSCs was further validated in vitro by cocultured adult rat cardiomyocytes with a stress-conditioned medium from Hsp20-MSCs. Taken together, these data support the premise that genetic modification of MSCs before transplantation could be salutary for treating myocardial infarction.
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Affiliation(s)
- Xiaohong Wang
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0575, USA
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44
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Jing H, Zhou X, Dong X, Cao J, Zhu H, Lou J, Hu Y, He Q, Yang B. Abrogation of Akt signaling by Isobavachalcone contributes to its anti-proliferative effects towards human cancer cells. Cancer Lett 2010; 294:167-77. [PMID: 20167420 DOI: 10.1016/j.canlet.2010.01.035] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 01/25/2010] [Accepted: 01/26/2010] [Indexed: 01/19/2023]
Abstract
Akt signaling pathway has attracted much attention as a promising target for cancer therapeutics. Herein, we report that Isobavachalcone (IBC), a natural chalcone, potently abrogates Akt signaling and exerts anti-proliferative effects on several human cancer cell lines. Modeling results from the Sybyl/FlexiDock program suggest that IBC potentially binds to the ATP-binding pocket of Akt, which is confirmed by the observations that IBC inhibits Akt1 kinase in vitro. Further studies reveal that IBC significantly abates Akt phosphorylation at Ser-473 and Akt kinase activity in cells, which subsequently leads to inhibition of Akt downstream substrates and evokes significant levels of apoptosis associated with mitochondria pathway.
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Affiliation(s)
- Hui Jing
- Institute of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
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45
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Katare RG, Caporali A, Oikawa A, Meloni M, Emanueli C, Madeddu P. Vitamin B1 analog benfotiamine prevents diabetes-induced diastolic dysfunction and heart failure through Akt/Pim-1-mediated survival pathway. Circ Heart Fail 2010; 3:294-305. [PMID: 20107192 DOI: 10.1161/circheartfailure.109.903450] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The increasing incidence of diabetes mellitus will result in a new epidemic of heart failure unless novel treatments able to halt diabetic cardiomyopathy early in its course are introduced. This study aimed to determine whether the activity of the Akt/Pim-1 signaling pathway is altered at critical stages of diabetic cardiomyopathy and whether supplementation with vitamin B1 analog benfotiamine (BFT) helps to sustain the above prosurvival mechanism, thereby preserving cardiomyocyte viability and function. METHODS AND RESULTS Untreated streptozotocin-induced type 1 or leptin-receptor mutant type 2 diabetic mice showed diastolic dysfunction evolving to contractile impairment and cardiac dilatation and failure. BFT (70 mg/kg(-1)/d(-1)) improved diastolic and systolic function and prevented left ventricular end-diastolic pressure increase and chamber dilatation in both diabetic models. Moreover, BFT improved cardiac perfusion and reduced cardiomyocyte apoptosis and interstitial fibrosis. In hearts of untreated diabetic mice, the expression and activity of Akt/Pim-1 signaling declined along with O-N-acetylglucosamine modification of Akt, inhibition of pentose phosphate pathway, activation of oxidative stress, and accumulation of glycation end products. Furthermore, diabetes reduced pSTAT3 independently of Akt. BFT inhibited these effects of diabetes mellitus, thereby conferring cardiomyocytes with improved resistance to high glucose-induced damage. The phosphoinositide-3-kinase inhibitor LY294002 and dominant-negative Akt inhibited antiapoptotic action of BFT-induced and Pim-1 upregulation in high glucose-challenged cardiomyocytes. CONCLUSIONS These results show that BFT protects from diabetes mellitus-induced cardiac dysfunction through pleiotropic mechanisms, culminating in the activation of prosurvival signaling pathway. Thus, BFT merits attention for application in clinical practice.
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Affiliation(s)
- Rajesh G Katare
- Experimental Cardiovascular Medicine, Bristol Heart Institute, University of Bristol, United Kingdom
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46
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Wang S, Wang Y, Jiang J, Wang R, Li L, Qiu Z, Wu H, Zhu D. 15-HETE protects rat pulmonary arterial smooth muscle cells from apoptosis via the PI3K/Akt pathway. Prostaglandins Other Lipid Mediat 2010; 91:51-60. [PMID: 20060487 DOI: 10.1016/j.prostaglandins.2009.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/15/2009] [Accepted: 12/22/2009] [Indexed: 12/01/2022]
Abstract
15-Hydroxyeicosatetraenoic acid (15-HETE), a metabolic product of arachidonic acid (AA), plays an important role in pulmonary vascular smooth muscle remodeling. Although its effects on the apoptotic responses are known, the underlying mechanisms are still poorly understood. Since Akt is a critical regulator of cell survival and vascular remodeling, there may be a crosstalk between 15-HETE anti-apoptotic process and PI3K/Akt survival effect in rat pulmonary arterial smooth muscle cells (PASMCs). To test this hypothesis, we studied the effect of 15-HETE on cell survival and apoptosis using Western blot, cell viability measurement, nuclear morphology determination, TUNEL assay and mitochondrial potential analysis. We found that activation of the PI3K/Akt signaling system was necessary for the 15-HETE to suppress PASMC apoptosis and improve cell survival. Our results indicated that 15-HETE inhibited the apoptotic responses of PASMCs, including morphological alterations, mitochondrial depolarization and the expression apoptosis-specific proteins. These effects were likely to be mediated through the activation of PI3K/Akt. Two downstream signal molecules of PI3K/Akt were identified. Both FasL and Bad were down-regulated by 15-HETE and 15-HETE phosphorylated Bad. These changes depended on the PI3K/Akt signaling pathway in PASMCs. Thus a signal transduction pathway was demonstrated which is necessary for the effects of 15-HETE in protection PASMCs from apoptosis.
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Affiliation(s)
- Shuang Wang
- Institute of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, Harbin 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081, PR China
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47
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Sussman MA. Mitochondrial integrity: preservation through Akt/Pim-1 kinase signaling in the cardiomyocyte. Expert Rev Cardiovasc Ther 2009; 7:929-38. [PMID: 19673671 DOI: 10.1586/erc.09.48] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The central role of mitochondria as mediators of cell survival is indisputable and gathering increasing attention as a focal point for interventional strategies to mitigate apoptotic cell death in the wake of cardiomyopathic injury. A legacy of signal transduction studies has proven that mitochondrial integrity can be enhanced by kinases involved in cell survival. Among the many survival signaling cascades under investigation, the wide-ranging impact of Akt upon mitochondrial biology is well known. However, despite years of investigation, emerging research continues to reveal new mechanisms governing the protective effects of Akt signaling in the context of cardiomyocyte mitochondria. This review focuses on two emerging pathways that mediate preservation of mitochondrial function downstream of Akt: hexokinase and Pim-1 kinase.
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Affiliation(s)
- Mark A Sussman
- San Diego State University, SDSU Heart Institute, Department of Biology, NLS 426, 5500 Campanile Drive, San Diego, CA 92182, USA.
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Interplay between MEK and PI3 kinase signaling regulates the subcellular localization of protein kinases ERK1/2 and Akt upon oxidative stress. FEBS Lett 2009; 583:1987-93. [PMID: 19446553 DOI: 10.1016/j.febslet.2009.05.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 04/30/2009] [Accepted: 05/06/2009] [Indexed: 11/22/2022]
Abstract
ERK and Akt kinases are key components that participate in numerous regulatory processes, including the response to stress. Using novel tools for quantitative immunofluorescence, we show that oxidant exposure controls the intracellular activation and localization of ERK1/2 and Akt. Oxidative stress alters the nuclear/cytoplasmic levels of the kinases, drastically changing phospho-ERK1/2 and phospho-Akt(Ser473) levels in the nucleus. Moreover, pharmacological inhibition of PI3 kinase modulates the intracellular distribution of phospho-ERK1/2, whereas MEK inhibition affects phospho-Akt(Thr308) and phospho-Akt(Ser473). Our studies identify a new signaling link in the nucleus of stressed cells, where changes in phospho-ERK1/2 levels correlate directly with changes in phospho-Akt(Ser473).
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Sun Y, Zhang Y, Yan M, Wu Y, Zheng X. B-Type Natriuretic Peptide-Induced Cardioprotection against Reperfusion Is Associated with Attenuation of Mitochondrial Permeability Transition. Biol Pharm Bull 2009; 32:1545-51. [DOI: 10.1248/bpb.32.1545] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yiguo Sun
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University
| | - Yun Zhang
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University
| | - Ming Yan
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University
| | - Yabin Wu
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University
| | - Xiaoxiang Zheng
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University
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