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Dong Y, Qu X, Wu G, Luo X, Tang B, Wu F, Fan L, Dev S, Liang T. Advances in the Detection, Mechanism and Therapy of Chronic Kidney Disease. Curr Pharm Des 2019; 25:4235-4250. [PMID: 31742493 DOI: 10.2174/1381612825666191119094354] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 10/30/2019] [Indexed: 01/08/2023]
Abstract
Chronic Kidney Disease (CKD) is characterized by the gradual loss of renal mass and functions. It has become a global health problem, with hundreds of millions of people being affected. Both its incidence and prevalence are increasing over time. More than $20,000 are spent on each patient per year. The economic burden on the patients, as well as the society, is heavy and their life quality worsen over time. However, there are still limited effective therapeutic strategies for CKD. Patients mainly rely on dialysis and renal transplantation, which cannot prevent all the complications of CKD. Great efforts are needed in understanding the nature of CKD progression as well as developing effective therapeutic methods, including pharmacological agents. This paper reviews three aspects in the research of CKD that may show great interests to those who devote to bioanalysis, biomedicine and drug development, including important endogenous biomarkers quantification, mechanisms underlying CKD progression and current status of CKD therapy.
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Affiliation(s)
- Yu Dong
- Department of Urology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, 530011, Nanning, China
| | - Xiaosheng Qu
- National Engineering Laboratory of Southwest Endangered Medicinal Resources Development, Guangxi Botanical Garden of Medicinal Plants, No. 189, Changgang Road, 530023, Nanning, China
| | - Gang Wu
- Department of Urology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, 530011, Nanning, China
| | - Xiangdong Luo
- Department of Urology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, 530011, Nanning, China
| | - Botao Tang
- Department of Urology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, 530011, Nanning, China
| | - Fangfang Wu
- National Engineering Laboratory of Southwest Endangered Medicinal Resources Development, Guangxi Botanical Garden of Medicinal Plants, No. 189, Changgang Road, 530023, Nanning, China
| | - Lanlan Fan
- School of Pharmacy, Guangxi University of Chinese Medicine, 530001, Nanning, China
| | - Sooranna Dev
- Department of Surgery and Cancer, Imperial College London, Chelsea and Westminster Hospital, 369, Fulham Road, London SW10 9NH, United Kingdom
| | - Taisheng Liang
- Department of Urology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, 530011, Nanning, China
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Protective Effect of Rosamultin against H 2O 2-Induced Oxidative Stress and Apoptosis in H9c2 Cardiomyocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8415610. [PMID: 30116494 PMCID: PMC6079377 DOI: 10.1155/2018/8415610] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/16/2018] [Accepted: 06/03/2018] [Indexed: 01/11/2023]
Abstract
Rosamultin is one of the main active compounds isolated from Potentilla anserina L., which belongs to a triterpene compound. Few studies have examined the effect of rosamultin on oxidative stress and its molecular mechanism. The aim of this present study was to elucidate the protective effect of rosamultin on H2O2-induced oxidative damage and apoptosis in H9c2 cardiomyocytes and its mechanism. The results showed that the pretreatment of rosamultin not only increased cell viability but also reduced the release of LDH and CK. Rosamultin inhibited a H2O2-induced decrease in SOD, CAT, and GSH-Px activities and an increase in MDA content. Meanwhile, ROS level, intracellular (Ca2+) fluorescence intensity, and apoptosis rate in the rosamultin pretreated group were markedly decreased compared with the model group. Rosamultin pretreatment significantly reversed the morphological changes and attenuated H2O2-induced apoptosis. Western blot analysis showed that rosamultin enhanced the expression of Bcl-2 and pCryAB and downregulated the expression of Bax, Cyt-c, Caspase-3, and Caspase-9 expression. Additionally, rosamultin might activate PI3K/Akt signal pathways and CryAB relative factors. Therefore, we suggest that rosamultin could have the potential for treating H2O2-induced oxidative stress injury through its antioxidant and antiapoptosis effect.
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Chen X, Wan J, Yu B, Diao Y, Zhang W. PIP5K1α promotes myogenic differentiation via AKT activation and calcium release. Stem Cell Res Ther 2018; 9:33. [PMID: 29426367 PMCID: PMC5806439 DOI: 10.1186/s13287-018-0770-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 12/01/2017] [Accepted: 01/05/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Skeletal muscle satellite cell-derived myoblasts are mainly responsible for postnatal muscle growth and injury-induced regeneration. Many intracellular signaling pathways are essential for myogenic differentiation, while a number of kinases are involved in this modulation process. Type I phosphatidylinositol 4-phosphate 5-kinase (PIP5KI) was identified as one of the key kinases involved in myogenic differentiation, but the underlying molecular mechanism is still unclear. METHODS PIP5K1α was quantified by quantitative reverse transcriptase PCR and western blot assay. Expression levels of myogenin and myosin heavy chain, which showed significant downregulation in PIP5K1α siRNA-mediated knockdown cells in western blot analysis, were confirmed by immunostaining. Phosphatidylinositol 4,5-bisphosphate in PIP5K1α siRNA-mediated knockdown cells was also measured by the PI(4,5)P2 Mass ELISA Kit. C2C12 cells were overexpressed with different forms of AKT, followed by western blot analysis on myogenin and myosin heavy chain, which reveals their function in myogenic differentiation. FLIPR assays are used to test the release of calcium in PIP5K1α siRNA-mediated knockdown cells after histamine or bradykinin treatment. Statistical significances between groups were determined by two-tailed Student's t test. RESULTS Since PIP5K1α was the major form in skeletal muscle, knockdown of PIP5K1α consistently inhibited myogenic differentiation while overexpression of PIP5K1α promoted differentiation and rescued the inhibitory effect of the siRNA. PIP5K1α was found to be required for AKT activation and calcium release, both of which were important for skeletal muscle differentiation. CONCLUSIONS Taken together, these results suggest that PIP5K1α is an important regulator in myoblast differentiation.
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Affiliation(s)
- Xiaofan Chen
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-the Hong Kong University of Science and Technology Medical Center, Lianhua Road 1120, Shenzhen, 518036, Guangdong Province, China
| | - Jun Wan
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-the Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Bo Yu
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-the Hong Kong University of Science and Technology Medical Center, Lianhua Road 1120, Shenzhen, 518036, Guangdong Province, China.,Department of Dermatology, Peking University Shenzhen Hospital, Shenzhen, 518036, Guangdong Province, China
| | - Yarui Diao
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-the Hong Kong University of Science and Technology Medical Center, Lianhua Road 1120, Shenzhen, 518036, Guangdong Province, China. .,Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
| | - Wei Zhang
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-the Hong Kong University of Science and Technology Medical Center, Lianhua Road 1120, Shenzhen, 518036, Guangdong Province, China.
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4
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Pomatto LCD, Wong S, Tower J, Davies KJA. Sexual dimorphism in oxidant-induced adaptive homeostasis in multiple wild-type D. melanogaster strains. Arch Biochem Biophys 2017; 636:57-70. [PMID: 29100984 DOI: 10.1016/j.abb.2017.10.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/13/2017] [Accepted: 10/27/2017] [Indexed: 11/24/2022]
Abstract
Sexual dimorphism includes the physical and reproductive differences between the sexes, including differences that are conserved across species, ranging from the common fruit fly, Drosophila melanogaster, to humans. Sex-dependent variations in adaptive homeostasis, and adaptive stress responses may offer insight into the underlying mechanisms for male and female survival differences and into differences in chronic disease incidence and severity in humans. Earlier work showed sex-specific differences in adaptive responses to oxidative stressors in hybrid laboratory strains of D. melanogaster. The present study explored whether this phenomenon is also observed in wild-type D. melanogaster strains Oregon-R (Or-R) and Canton-S (Ca-S), as well as the common mutant reference strain w[1118], in order to better understand whether such findings are descriptive of D. melanogaster in general. Flies of each strain were pretreated with non-damaging, adaptive concentrations of hydrogen peroxide (H2O2) or of different redox cycling agents (paraquat, DMNQ, or menadione). Adaptive homeostasis, and changes in the expression of the Proteasome and overall cellular proteasomal proteolytic capacity were assessed. Redox cycling agents exhibited a male-specific adaptive response, whereas H2O2 exposure provoked female-specific adaptation. These findings demonstrate that different oxidants can elicit sexually dimorphic adaptive homeostatic responses in multiple fly strains. These results (and those contained in a parallel study [1]) highlight the need to address sex as a biological variable in fundamental science, clinical research, and toxicology.
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Affiliation(s)
- Laura C D Pomatto
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, The University of Southern California, Los Angeles, CA 00089-0191, USA
| | - Sarah Wong
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, The University of Southern California, Los Angeles, CA 00089-0191, USA
| | - John Tower
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, The University of Southern California, Los Angeles, CA 00089-0191, USA,; Molecular and Computational Biology Program of the Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Kelvin J A Davies
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, The University of Southern California, Los Angeles, CA 00089-0191, USA,; Molecular and Computational Biology Program of the Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, CA 90089-0191, USA.
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5
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Zhu C, Wang Y, Liu H, Mu H, Lu Y, Zhang J, Huang J. Oral administration of Ginsenoside Rg1 prevents cardiac toxicity induced by doxorubicin in mice through anti-apoptosis. Oncotarget 2017; 8:83792-83801. [PMID: 29137383 PMCID: PMC5663555 DOI: 10.18632/oncotarget.19698] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/28/2017] [Indexed: 11/25/2022] Open
Abstract
Although Ginsenoside Rg1 has been reported to have protective cardiac effects, its effects on cardiac toxicity induced by doxorubicin needs to be studied. The present study investigated the effects of oral administration of Rg1 on the heart in mice treated with doxorubicin and found improved fractional shortening and ejection fraction of the heart and decreased cardiac apoptosis in mice treated with doxorubicin. The underlying mechanisms include increased phosphorylation of Akt and Erk by Rg1, increased ratio of Bcl-2 and Bax, and decreased release of cytochrome c from mitochondria, thereby protecting the heart from doxorubicin-induced apoptosis. This phenotype suggested that the oral administration of Rg1 may be a potential method preventing the cardiac toxicity caused by doxorubicin in clinical practice.
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Affiliation(s)
- Chen Zhu
- First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China.,Graduated School of Jinzhou Medical University, Jinzhou, China
| | - Yi Wang
- First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Hua Liu
- Third Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Haiman Mu
- First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Yue Lu
- Graduated School of Jinzhou Medical University, Jinzhou, China
| | - Jiayi Zhang
- First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Jianhua Huang
- First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
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6
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Kuczkowski A, Brinkkoetter PT. Metabolism and homeostasis in the kidney: metabolic regulation through insulin signaling in the kidney. Cell Tissue Res 2017; 369:199-210. [DOI: 10.1007/s00441-017-2619-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/22/2017] [Indexed: 02/07/2023]
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7
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Oster M, Trakooljul N, Reyer H, Zeyner A, Muráni E, Ponsuksili S, Wimmers K. Sex-Specific Muscular Maturation Responses Following Prenatal Exposure to Methylation-Related Micronutrients in Pigs. Nutrients 2017; 9:nu9010074. [PMID: 28106759 PMCID: PMC5295118 DOI: 10.3390/nu9010074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/21/2016] [Accepted: 12/22/2016] [Indexed: 01/22/2023] Open
Abstract
Supplementation of micronutrients involved in DNA methylation, particularly during pregnancy, is recommended because of its impacts on human health, but further evidence is needed regarding the effects of over-supplementation and differences between sexes. Here, a porcine model was used to assess effects of maternal supplementation with one-carbon-cycle compounds during prenatal and postnatal stages on offspring muscle development. Sows received either a standard diet (CON) or a standard diet supplemented with folate, B6, B12, methionine, choline, and zinc (MET) throughout gestation. Myogenesis-, growth-, and nutrient utilization-related transcript expression was assessed using quantitative PCR. Organismal phenotype and gene expression effects differed significantly between males and females. Male MET-offspring showed increased fetal weight during late pregnancy but decreased live weight postnatally, with compensatory transcriptional responses comprising myogenic key drivers (Pax7, MyoD1, myogenin). In contrast, female weights were unaffected by diet, and mRNA abundances corresponded to a phenotype of cellular reorganization via FABP3, FABP4, SPP1 and Insulin-like Growth Factor-signaling. These findings in an animal model suggest that supplementation during pregnancy with methylation-related micronutrients can promote sex-specific myogenic maturation processes related to organismal growth and muscle metabolism. The usage of maternal dietary supplements should be more carefully considered regarding its ability to promote fetal and postnatal health.
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Affiliation(s)
- Michael Oster
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
| | - Nares Trakooljul
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
| | - Henry Reyer
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
| | - Annette Zeyner
- Martin-Luther-University Halle-Wittenberg, Department of Animal Nutrition, Theodor-Lieser-Str. 11, 06120 Halle (Saale), Germany.
| | - Eduard Muráni
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
| | - Siriluck Ponsuksili
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
| | - Klaus Wimmers
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
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8
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Hang P, Zhao J, Sun L, Li M, Han Y, Du Z, Li Y. Brain-derived neurotrophic factor attenuates doxorubicin-induced cardiac dysfunction through activating Akt signalling in rats. J Cell Mol Med 2016; 21:685-696. [PMID: 28098423 PMCID: PMC5345637 DOI: 10.1111/jcmm.13012] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/18/2016] [Indexed: 12/21/2022] Open
Abstract
The clinical application of doxorubicin (Dox) is limited by its adverse effect of cardiotoxicity. Previous studies have suggested the cardioprotective effect of brain‐derived neurotrophic factor (BDNF). We hypothesize that BDNF could protect against Dox‐induced cardiotoxicity. Sprague Dawley rats were injected with Dox (2.5 mg/kg, 3 times/week, i.p.), in the presence or absence of recombinant BDNF (0.4 μg/kg, i.v.) for 2 weeks. H9c2 cells were treated with Dox (1 μM) and/or BDNF (400 ng/ml) for 24 hrs. Functional roles of BDNF against Dox‐induced cardiac injury were examined both in vivo and in vitro. Protein level of BDNF was reduced in Dox‐treated rat ventricles, whereas BDNF and its receptor tropomyosin‐related kinase B (TrkB) were markedly up‐regulated after BDNF administration. Brain‐derived neurotrophic factor significantly inhibited Dox‐induced cardiomyocyte apoptosis, oxidative stress and cardiac dysfunction in rats. Meanwhile, BDNF increased cell viability, inhibited apoptosis and DNA damage of Dox‐treated H9c2 cells. Investigations of the underlying mechanisms revealed that BDNF activated Akt and preserved phosphorylation of mammalian target of rapamycin and Bad without affecting p38 mitogen‐activated protein kinase and extracellular regulated protein kinase pathways. Furthermore, the beneficial effect of BDNF was abolished by BDNF scavenger TrkB‐Fc or Akt inhibitor. In conclusion, our findings reveal a potent protective role of BDNF against Dox‐induced cardiotoxicity by activating Akt signalling, which may facilitate the safe use of Dox in cancer treatment.
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Affiliation(s)
- Pengzhou Hang
- Institute of Clinical Pharmacology, The Second Affiliated Hospital (Key Laboratory of Drug Research, Heilongjiang Higher Education Institutions), Harbin Medical University, Harbin, China.,Heilongjiang Academy of Medical Science, Harbin, China
| | - Jing Zhao
- Department of Cardiology, The First Affiliated Hospital (Key Laboratory of Cardiac Diseases and Heart Failure), Harbin Medical University, Harbin, China
| | - Li Sun
- Department of Cardiology, The First Affiliated Hospital (Key Laboratory of Cardiac Diseases and Heart Failure), Harbin Medical University, Harbin, China
| | - Minghui Li
- Department of Cardiology, The First Affiliated Hospital (Key Laboratory of Cardiac Diseases and Heart Failure), Harbin Medical University, Harbin, China
| | - Yu Han
- Department of Cardiology, The First Affiliated Hospital (Key Laboratory of Cardiac Diseases and Heart Failure), Harbin Medical University, Harbin, China
| | - Zhimin Du
- Institute of Clinical Pharmacology, The Second Affiliated Hospital (Key Laboratory of Drug Research, Heilongjiang Higher Education Institutions), Harbin Medical University, Harbin, China
| | - Yue Li
- Heilongjiang Academy of Medical Science, Harbin, China.,Department of Cardiology, The First Affiliated Hospital (Key Laboratory of Cardiac Diseases and Heart Failure), Harbin Medical University, Harbin, China
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Abstract
Homeostasis is a central pillar of modern Physiology. The term homeostasis was invented by Walter Bradford Cannon in an attempt to extend and codify the principle of 'milieu intérieur,' or a constant interior bodily environment, that had previously been postulated by Claude Bernard. Clearly, 'milieu intérieur' and homeostasis have served us well for over a century. Nevertheless, research on signal transduction systems that regulate gene expression, or that cause biochemical alterations to existing enzymes, in response to external and internal stimuli, makes it clear that biological systems are continuously making short-term adaptations both to set-points, and to the range of 'normal' capacity. These transient adaptations typically occur in response to relatively mild changes in conditions, to programs of exercise training, or to sub-toxic, non-damaging levels of chemical agents; thus, the terms hormesis, heterostasis, and allostasis are not accurate descriptors. Therefore, an operational adjustment to our understanding of homeostasis suggests that the modified term, Adaptive Homeostasis, may be useful especially in studies of stress, toxicology, disease, and aging. Adaptive Homeostasis may be defined as follows: 'The transient expansion or contraction of the homeostatic range in response to exposure to sub-toxic, non-damaging, signaling molecules or events, or the removal or cessation of such molecules or events.'
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Affiliation(s)
- Kelvin J A Davies
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, The University of Southern California, Los Angeles, CA 90089-0191, USA; Division of Molecular and Computational Biology, Department of Biological Sciences, Dornsife College of Letters, Arts, & Sciences, The University of Southern California, Los Angeles, CA 90089-0191, USA.
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10
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Bienaimé F, Canaud G, El Karoui K, Gallazzini M, Terzi F. Molecular pathways of chronic kidney disease progression. Nephrol Ther 2016; 12 Suppl 1:S35-8. [DOI: 10.1016/j.nephro.2016.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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11
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Hwang SY, Kang YJ, Sung B, Kim M, Kim DH, Lee Y, Yoo MA, Kim CM, Chung HY, Kim ND. Folic acid promotes the myogenic differentiation of C2C12 murine myoblasts through the Akt signaling pathway. Int J Mol Med 2015; 36:1073-80. [PMID: 26310574 DOI: 10.3892/ijmm.2015.2311] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/10/2015] [Indexed: 11/05/2022] Open
Abstract
Folic acid is a water-soluble vitamin in the B-complex group, and an exogenous intake is required for health, growth and development. As a precursor to co-factors, folic acid is required for one-carbon donors in the synthesis of DNA bases and other essential biomolecules. A lack of dietary folic acid can lead to folic acid deficiency and can therefore result in several health problems, including macrocytic anemia, elevated plasma homocysteine levels, cardiovascular disease, birth defects, carcinogenesis, muscle weakness and difficulty in walking. Previous studies have indicated that folic acid exerts a positive effect on skeletal muscle functions. However, the precise role of folic acid in skeletal muscle cell differentiation remains poorly understood. Thus, in the present study, we examined the effects of folic acid on neo-myotube maturation and differentiation using C2C12 murine myoblasts. We found that folic acid promoted the formation of multinucleated myotubes, and increased the fusion index and creatine kinase (CK) activity in a concentration-dependent manner. In addition, western blot analysis revealed that the expression levels of the muscle-specific marker, myosin heavy chain (MyHC), as well as those of the myogenic regulatory factors (MRFs), MyoD and myogenin, were increased in the folic acid-treated myotubes during myogenic differentiation. Folic acid also promoted the activation of the Akt pathway, and this effect was inhibited by treatment of the C2C12 cells with LY294002 (Akt inhibitor). Blocking of the Akt pathway with a specific inhibitor revealed that it was necessary for mediating the stimulatory effects of folic acid on muscle cell differentiation and fusion. Taken together, our data suggest that folic acid promotes the differentiation of C2C12 cells through the activation of the Akt pathway.
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Affiliation(s)
- Seong Yeon Hwang
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Yong Jung Kang
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Bokyung Sung
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Minjung Kim
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Dong Hwan Kim
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Yujin Lee
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Mi-Ae Yoo
- Department of Molecular Biology, Pusan National University, Busan 609-735, Republic of Korea
| | - Cheol Min Kim
- Research Center for Anti-Aging Technology Development, Pusan National University, Busan 609-735, Republic of Korea
| | - Hae Young Chung
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
| | - Nam Deuk Kim
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735, Republic of Korea
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12
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Shi YF, Liu N, Li YX, Song CL, Song XJ, Zhao Z, Liu B. Insulin protects H9c2 rat cardiomyoblast cells against hydrogen peroxide-induced injury through upregulation of microRNA-210. Free Radic Res 2015; 49:1147-55. [PMID: 25968948 DOI: 10.3109/10715762.2015.1050588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Insulin protects cardiomyocytes from reactive oxygen species (ROS)-induced apoptosis after ischemic/reperfusion injury, but the mechanism is not clear. This study investigated the protective mechanism of insulin in preventing cardiomyocyte apoptosis from ROS injury. METHODS Rat cardiomyoblast H9c2 cells were treated with hydrogen peroxide (H2O2) or insulin at various concentrations for various periods of time, or with insulin and H2O2 for various periods of time. Cell viability was measured by the methylthiazolydiphenyl-tetrazolium bromide method. Cellular miR-210 levels were quantified using real-time RT-PCR. MiR-210 expression was also manipulated through lentivirus-mediated transfection. LY294002 was used to investigate involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. RESULTS The percentage of viable cells was significantly and inversely associated with H2O2 concentration, an effect that was seemingly attenuated by insulin pretreatment. Treatments with H2O2 or insulin were associated with a significant increase in miR-210 levels. Manipulation of miR-210 expression by gene transfection showed that miR-210 could attenuate H2O2-induced cellular injury. Inhibition of the PI3K/Akt pathway by the Akt inhibitor LY294002 was associated with a decrease in miR-210 expression. CONCLUSION Insulin stimulated the expression of miR-210 through the PI3K/Akt pathway, resulting in a protective effect against cardiomyocyte injury that had been induced by H2O2/oxygen species. Our results provide novel evidence regarding the mechanism underlying the protective effect of insulin.
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Affiliation(s)
- Y-F Shi
- Department of Cardiology, The Second Hospital of Jilin University, Jilin University , Changchun , China
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13
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Walker N, Kahamba T, Woudberg N, Goetsch K, Niesler C. Dose-dependent modulation of myogenesis by HGF: implications for c-Met expression and downstream signalling pathways. Growth Factors 2015; 33:229-41. [PMID: 26135603 DOI: 10.3109/08977194.2015.1058260] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hepatocyte growth factor (HGF) regulates satellite cell activation, proliferation, and differentiation. We analyzed the dose-dependent effects of HGF on myogenesis. Murine C2C12 and human donor-derived skeletal muscle myoblasts were treated with 0, 2, or 10 ng/ml HGF followed by assessment of proliferation and differentiation. HGF (2 ng/ml) significantly promoted cell division, but reduced myogenic commitment and fusion. Conversely, 10 ng/ml HGF reduced proliferative capability, but increased differentiation. c-Met expression analysis revealed significantly decreased expression in differentiating cells cultured with 2 ng/ml HGF, but increased expression in proliferating cells with 10 ng/ml HGF. Mitogen-activated protein kinase (MAPKs: ERK, JNK, or p38K) and phosphatidylinositol-3-kinase (PI3K) inhibition abrogated the HGF-stimulated increase in cell number. Interestingly, PI3K and p38 kinase facilitated the negative effect of HGF on proliferation, while ERK inhibition abrogated the HGF-mediated decrease in differentiation. Dose-dependent effects of HGF are mediated by changes in c-Met expression and downstream MAPK and PI3K signalling.
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Affiliation(s)
- Nicholas Walker
- a Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal , Scottsville , South Africa
| | - Trish Kahamba
- a Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal , Scottsville , South Africa
| | - Nicholas Woudberg
- a Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal , Scottsville , South Africa
| | - Kyle Goetsch
- a Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal , Scottsville , South Africa
| | - Carola Niesler
- a Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal , Scottsville , South Africa
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microRNAs in heart failure. Chin Med J (Engl) 2014. [DOI: 10.1097/00029330-201409200-00024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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15
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The PPARβ/δ agonist GW0742 modulates signaling pathways associated with cardiac myocyte growth via a non-genomic redox mechanism. Mol Cell Biochem 2014; 395:145-54. [PMID: 24939361 DOI: 10.1007/s11010-014-2120-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/02/2014] [Indexed: 12/28/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that belong to the nuclear hormone receptor superfamily and appear to have beneficial effects in the cardiovascular system. PPARβ/δ has been shown previously to exert an inhibitory effect on cardiac myocyte hypertrophy in vivo and in vitro although the exact mechanism is not fully clear yet. The principal signaling pathways that have been involved in triggering cardiac hypertrophic response are mitogen-activated protein kinases (MAPKs) and PI3K/Akt cascades. In this study, we sought to evaluate the potential effects evoked by PPARβ/δ activation on signaling pathways that are implicated in cardiac myocyte growth responses. The selective PPARβ/δ agonist GW0742 attenuated ERK1/2 and Akt phosphorylation that was stimulated by growth promoting agonists (phenylephrine, insulin or IGF-1). This effect was not reversed by the specific PPARβ/δ antagonist, GSK0660, but was inhibited by vanadate, a potent protein tyrosine phosphatase inhibitor. In addition, GW0742 prevented the oxidation and inactivation of PTEN supporting further the notion that its inhibitory action on the agonist-induced kinase phosphorylation is mediated by the modulation of phosphatase activity. Furthermore, GW0742 abolished the agonist-induced intracellular generation of reactive oxygen species, independently of PPARβ/δ activation. Our data reveals a new non-genomic mechanism of GW0742, which ameliorates the generation of reactive oxygen species and attenuates ERK1/2 and PI3K/Akt signaling, with implications in the regulation of cardiac hypertrophic response.
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16
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Swaminathan S, Rosner MH. The podocyte under stress: AKT2 to the rescue. Am J Kidney Dis 2014; 63:555-7. [PMID: 24480654 DOI: 10.1053/j.ajkd.2014.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 01/09/2014] [Indexed: 01/10/2023]
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17
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Dostal DE, Feng H, Nizamutdinov D, Golden HB, Afroze SH, Dostal JD, Jacob JC, Foster DM, Tong C, Glaser S, Gerilechaogetu F. Mechanosensing and Regulation of Cardiac Function. ACTA ACUST UNITED AC 2014; 5:314. [PMID: 25485172 PMCID: PMC4255974 DOI: 10.4172/2155-9880.1000314] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The role of mechanical force as an important regulator of structure and function of mammalian cells, tissues, and organs has recently been recognized. However, mechanical overload is a pathogenesis or comorbidity existing in a variety of heart diseases, such as hypertension, aortic regurgitation and myocardial infarction. Physical stimuli sensed by cells are transmitted through intracellular signal transduction pathways resulting in altered physiological responses or pathological conditions. Emerging evidence from experimental studies indicate that β1-integrin and the angiotensin II type I (AT1) receptor play critical roles as mechanosensors in the regulation of heart contraction, growth and leading to heart failure. Integrin link the extracellular matrix and the intracellular cytoskeleton to initiate the mechanical signalling, whereas, the AT1 receptor could be activated by mechanical stress through an angiotensin-II-independent mechanism. Recent studies show that both Integrin and AT1 receptor and their downstream signalling factors including MAPKs, AKT, FAK, ILK and GTPase regulate heart function in cardiac myocytes. In this review we describe the role of mechanical sensors residing within the plasma membrane, mechanical sensor induced downstream signalling factors and its potential roles in cardiac contraction and growth.
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Affiliation(s)
- David E Dostal
- Central Texas Veterans Health Care System, Temple, Texas, USA ; Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Hao Feng
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Damir Nizamutdinov
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Honey B Golden
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Syeda H Afroze
- Scott & White Healthcare - Digestive Disease Research Centre, Temple, Texas, USA
| | - Joseph D Dostal
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - John C Jacob
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Donald M Foster
- Central Texas Veterans Health Care System, Temple, Texas, USA
| | - Carl Tong
- Systems Biology and Translational Medicine, the Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
| | - Shannon Glaser
- Central Texas Veterans Health Care System, Temple, Texas, USA ; Scott & White Healthcare - Digestive Disease Research Centre, Temple, Texas, USA
| | - Fnu Gerilechaogetu
- Division of Molecular Cardiology, Cardiovascular Research Institute, Texas A&M University Health Science Centre, College of Medicine, Temple, Texas, USA
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18
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Canaud G, Bienaimé F, Viau A, Treins C, Baron W, Nguyen C, Burtin M, Berissi S, Giannakakis K, Muda AO, Zschiedrich S, Huber TB, Friedlander G, Legendre C, Pontoglio M, Pende M, Terzi F. AKT2 is essential to maintain podocyte viability and function during chronic kidney disease. Nat Med 2013; 19:1288-96. [PMID: 24056770 DOI: 10.1038/nm.3313] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 07/19/2013] [Indexed: 02/06/2023]
Abstract
In chronic kidney disease (CKD), loss of functional nephrons results in metabolic and mechanical stress in the remaining ones, resulting in further nephron loss. Here we show that Akt2 activation has an essential role in podocyte protection after nephron reduction. Glomerulosclerosis and albuminuria were substantially worsened in Akt2(-/-) but not in Akt1(-/-) mice as compared to wild-type mice. Specific deletion of Akt2 or its regulator Rictor in podocytes revealed that Akt2 has an intrinsic function in podocytes. Mechanistically, Akt2 triggers a compensatory program that involves mouse double minute 2 homolog (Mdm2), glycogen synthase kinase 3 (Gsk3) and Rac1. The defective activation of this pathway after nephron reduction leads to apoptosis and foot process effacement of the podocytes. We further show that AKT2 activation by mammalian target of rapamycin complex 2 (mTORC2) is also required for podocyte survival in human CKD. More notably, we elucidate the events underlying the adverse renal effect of sirolimus and provide a criterion for the rational use of this drug. Thus, our results disclose a new function of Akt2 and identify a potential therapeutic target for preserving glomerular function in CKD.
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Affiliation(s)
- Guillaume Canaud
- 1] Institut National de la Santé et de la Recherche Médicale (INSERM) U845, Centre de Recherche 'Croissance et Signalisation', Université Paris Descartes, Sorbonne Paris Cité, Hôpital Necker-Enfants Malades, Paris, France. [2] Service de Néphrologie Transplantation Adultes, Hôpital Necker-Enfants Malades, Paris, France. [3]
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19
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Leite-Moreira AM, Lourenço AP, Falcão-Pires I, Leite-Moreira AF. Pivotal role of microRNAs in cardiac physiology and heart failure. Drug Discov Today 2013; 18:1243-9. [PMID: 23954179 DOI: 10.1016/j.drudis.2013.07.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 06/30/2013] [Accepted: 07/17/2013] [Indexed: 01/28/2023]
Abstract
Cardiac hypertrophy is a hallmark of heart failure (HF), a highly prevalent, debilitating and deadly condition in Western countries. Pronounced changes in molecular pathways governing cardiac physiology underlie hypertrophy and progression to HF. MicroRNAs, small nucleotide sequences that coordinate gene expression, may have a central role in orchestrating these changes since the hypertrophic and HF myocardium clearly shows disturbed microRNA profiles. Experimental interventions targeting miR disturbances have been shown beneficial in animal models of cardiac hypertrophy and HF. This short review discusses exciting potential diagnostic and therapeutic applications of microRNAs to cardiac hypertrophy and HF, highlighting the underlying molecular pathways.
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Affiliation(s)
- André M Leite-Moreira
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Portugal
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20
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Buitrago C, Pardo VG, Boland R. Role of VDR in 1α,25-dihydroxyvitamin D3-dependent non-genomic activation of MAPKs, Src and Akt in skeletal muscle cells. J Steroid Biochem Mol Biol 2013; 136:125-30. [PMID: 23470620 DOI: 10.1016/j.jsbmb.2013.02.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 02/18/2013] [Accepted: 02/21/2013] [Indexed: 10/27/2022]
Abstract
1α,25-dihydroxyvitamin D3 [1,25D] is recognized as a steroid hormone that rapidly elicits intracellular signals in various tissues. In skeletal myoblasts, we have previously demonstrated that one of the 1,25D-induced non-genomic effects is the upstream stimulation of MAPKs through Src activation. In this work, the data obtained suggest that the classical receptor of vitamin D (VDR) participates in non-transcriptional actions of 1,25D. We significantly reduced VDR expression by infection of C2C12 murine myoblasts with lentiviral particles containing the pLKO.1 plasmid with information to express a shRNA against mouse VDR. In these cells (C2C12-shVDR), Western blot analyses show that 1,25D-induced p38 MAPK activation and Src tyr416 phosphorylation were abolished. In addition, 1,25D-dependent activity of ERK1/2 was diminished in cells lacking VDR but to a lesser extent (∼-60%). Phosphorylation of Akt by 1,25D, recently demonstrated in C2C12 cells, in the present work also appeared to be partially dependent on VDR expression (∼50% in C2C12-shVDR cells). Our results indicate that VDR is involved in 1,25D-induced rapid events related to survival/proliferation responses in skeletal muscle cells, providing relevant information on the mechanism of initiation of the non-genomic hormone signal. The participation of a VDR-independent non-genomic mechanism of action should also be taken into consideration. This article is part of a Special Issue entitled 'Vitamin D Workshop'.
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Affiliation(s)
- Claudia Buitrago
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina.
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21
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Ganesan J, Ramanujam D, Sassi Y, Ahles A, Jentzsch C, Werfel S, Leierseder S, Loyer X, Giacca M, Zentilin L, Thum T, Laggerbauer B, Engelhardt S. MiR-378 controls cardiac hypertrophy by combined repression of mitogen-activated protein kinase pathway factors. Circulation 2013; 127:2097-106. [PMID: 23625957 DOI: 10.1161/circulationaha.112.000882] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Several microRNAs (miRs) have been shown to regulate gene expression in the heart, and dysregulation of their expression has been linked to cardiac disease. miR-378 is strongly expressed in the mammalian heart but so far has been studied predominantly in cancer, in which it regulates cell survival and tumor growth. METHODS AND RESULTS Here, we report tight control of cardiomyocyte hypertrophy through miR-378. In isolated primary cardiomyocytes, miR-378 was found to be both necessary and sufficient to repress cardiomyocyte hypertrophy. Bioinformatic prediction suggested that factors of the mitogen-activated protein kinase (MAPK) pathway are enriched among miR-378 targets. Using mRNA and protein expression analysis along with luciferase assays, we validated 4 key components of the MAPK pathway as targets of miR-378: MAPK1 itself, insulin-like growth factor receptor 1, growth factor receptor-bound protein 2, and kinase suppressor of ras 1. RNA interference with these targets prevented the prohypertrophic effect of antimiR-378, suggesting their functional relation with miR-378. Because miR-378 significantly decreases in cardiac disease, we sought to compensate for its loss through adeno-associated virus-mediated, cardiomyocyte-targeted expression of miR-378 in an in vivo model of cardiac hypertrophy (pressure overload by thoracic aortic constriction). Restoration of miR-378 levels significantly attenuated thoracic aortic constriction-induced cardiac hypertrophy and improved cardiac function. CONCLUSIONS Our data identify miR-378 as a regulator of cardiomyocyte hypertrophy, which exerts its activity by suppressing the MAPK signaling pathway on several distinct levels. Restoration of disease-associated loss of miR-378 through cardiomyocyte-targeted adeno-associated virus-miR-378 may prove to be an effective therapeutic strategy in myocardial disease.
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Affiliation(s)
- Jayavarshni Ganesan
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Munich, Germany
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22
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Buitrago CG, Arango NS, Boland RL. 1α,25(OH)2D3-dependent modulation of Akt in proliferating and differentiating C2C12 skeletal muscle cells. J Cell Biochem 2012; 113:1170-81. [PMID: 22095470 DOI: 10.1002/jcb.23444] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We previously reported that 1α,25-dihydroxy-vitamin D(3) [1α,25(OH)(2)D(3)] induces non-transcriptional rapid responses through activation of Src and MAPKs in the skeletal muscle cell line C2C12. In the present study we investigated the modulation of Akt by the secosteroid hormone in C2C12 cells at proliferative stage (myoblasts) and at early differentiation stage. In proliferating cells, 1α,25(OH)(2)D(3) activates Akt by phosphorylation in Ser473 in a time-dependent manner (5-60 min). When these cells were pretreated with methyl-beta-cyclodextrin to disrupt caveolae microdomains, hormone-induced activation of Akt was suppressed. Similar results were obtained by siRNA silencing of caveolin-1 expression, further indicating that hormone effects on cell membrane caveolae are required for downstream signaling. PI3K and p38 MAPK, but not ERK1/2, participate in 1α,25(OH)(2)D(3) activation of Akt in myoblasts. The involvement of p38 MAPK in Akt phosphorylation by the hormone probably occurs through MAPK-activated protein kinase 2 (MK2), which is activated by the steroid. In addition, the participation of Src in Akt phosphorylation by 1α,25(OH)(2)D(3) was demonstrated using the inhibitor PP2 and antisense oligodeoxynucleotides that suppress Src expression. We also observed that PI3K participates in hormone-induced proliferation. During the early phase of C2C12 cell differentiation 1α,25(OH)(2)D(3) also increases Akt phosphorylation and activates Src. Of relevance, Src and PI3K are involved in Akt activation and in MHC and myogenin increased expression by 1α,25(OH)(2)D(3). Altogether, these data suggest that 1α,25(OH)(2)D(3) upregulates Akt through Src, PI(3)K, and p38 MAPK to stimulate myogenesis in C2C12 cells.
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Affiliation(s)
- Claudia G Buitrago
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina
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23
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Klement GL, Goukassian D, Hlatky L, Carrozza J, Morgan JP, Yan X. Cancer Therapy Targeting the HER2-PI3K Pathway: Potential Impact on the Heart. Front Pharmacol 2012; 3:113. [PMID: 22754526 PMCID: PMC3384262 DOI: 10.3389/fphar.2012.00113] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 05/24/2012] [Indexed: 01/22/2023] Open
Abstract
The HER2-PI3K pathway is the one of the most mutated pathways in cancer. Several drugs targeting the major kinases of this pathway have been approved by the Food and Drug Administration and many are being tested in clinical trials for the treatment of various cancers. However, the HER2-PI3K pathway is also pivotal for maintaining the physiological function of the heart, especially in the presence of cardiac stress. Clinical studies have shown that in patients treated with doxorubicin concurrently with Trastuzumab, a monoclonal antibody that blocks the HER2 receptor, the New York Heart Association class III/IV heart failure was significantly increased compared to those who were treated with doxorubicin alone (16 vs. 3%). Studies in transgenic mice have also shown that other key kinases of this pathway, such as PI3Kα, PDK1, Akt, and mTOR, are important for protecting the heart from ischemia-reperfusion and aortic stenosis induced cardiac dysfunction. Studies, however, have also shown that inhibition of PI3Kγ improve cardiac function of a failing heart. In addition, results from transgenic mouse models are not always consistent with the outcome of the pharmacological inhibition of this pathway. Here, we will review these findings and discuss how we can address the cardiac side-effects caused by inhibition of this important pathway in both cancer and cardiac biology.
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Affiliation(s)
- Giannoula L Klement
- Center of Cancer Systems Biology, St. Elizabeth's Medical Center, Tufts University School of Medicine Boston, MA, USA
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24
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Buss SJ, Riffel JH, Malekar P, Hagenmueller M, Asel C, Zhang M, Weiss C, Katus HA, Hardt SE. Chronic Akt blockade aggravates pathological hypertrophy and inhibits physiological hypertrophy. Am J Physiol Heart Circ Physiol 2011; 302:H420-30. [PMID: 22058151 DOI: 10.1152/ajpheart.00211.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The attenuation of adverse myocardial remodeling and pathological left ventricular (LV) hypertrophy is one of the hallmarks for improving the prognosis after myocardial infarction (MI). The protein kinase Akt plays a central role in regulating cardiac hypertrophy, but the in vivo effects of chronic pharmacological inhibition of Akt are unknown. We investigated the effect of chronic Akt blockade with deguelin on the development of pathological [MI and aortic banding (AB)] and physiological (controlled treadmill running) hypertrophy. Primary cardiomyocyte cultures were incubated with 10 μmol deguelin for 48 h, and Wistar rats were treated orally with deguelin (4.0 mg·kg(-1)·day(-1)) for 4 wk starting 1 day after the induction of MI or AB. Exercise-trained animals received deguelin for 4 wk during the training period. In vitro, we observed reduced phosphorylation of Akt and glycogen synthase kinase (GSK)-3β after an incubation with deguelin, whereas MAPK signaling was not significantly affected. In vivo, treatment with deguelin led to attenuated phosphorylation of Akt and GSK-3β 4 wk after MI. These animals showed significantly increased heart weights and impaired LV function with increased end-diastolic diameters (12.0 ± 0.3 vs. 11.1 ± 0.3 mm, P < 0.05), end-diastolic volumes (439 ± 8 vs. 388 ± 18 μl, P < 0.05), and cardiomyocyte sizes (+20%, P < 0.05) compared with MI animals receiving vehicle treatment. Furthermore, activation of Ca(2+)/calmodulin-dependent kinase II in deguelin-treated MI animals was increased compared with the vehicle-treated group. Four wk after AB, we observed an augmentation of pathological hypertrophy in the deguelin-treated group with a significant increase in heart weights and cardiomyocyte sizes (>20%, P < 0.05). In contrast, the development of physiological hypertrophy was inhibited by deguelin treatment in exercise-trained animals. In conclusion, chronic Akt blockade with deguelin aggravates adverse myocardial remodeling and antagonizes physiological hypertrophy.
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Affiliation(s)
- Sebastian J Buss
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, Heidelberg, Germany
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25
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Clemente CFMZ, Xavier-Neto J, Dalla Costa AP, Consonni SR, Antunes JE, Rocco SA, Pereira MB, Judice CC, Strauss B, Joazeiro PP, Matos-Souza JR, Franchini KG. Focal adhesion kinase governs cardiac concentric hypertrophic growth by activating the AKT and mTOR pathways. J Mol Cell Cardiol 2011; 52:493-501. [PMID: 22056317 DOI: 10.1016/j.yjmcc.2011.10.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 09/16/2011] [Accepted: 10/19/2011] [Indexed: 11/29/2022]
Abstract
The heart responds to sustained overload by hypertrophic growth in which the myocytes distinctly thicken or elongate on increases in systolic or diastolic stress. Though potentially adaptive, hypertrophy itself may predispose to cardiac dysfunction in pathological settings. The mechanisms underlying the diverse morphology and outcomes of hypertrophy are uncertain. Here we used a focal adhesion kinase (FAK) cardiac-specific transgenic mice model (FAK-Tg) to explore the function of this non-receptor tyrosine kinase on the regulation of myocyte growth. FAK-Tg mice displayed a phenocopy of concentric cardiac hypertrophy, reflecting the relative thickening of the individual myocytes. Moreover, FAK-Tg mice showed structural, functional and molecular features of a compensated hypertrophic growth, and preserved responses to chronic pressure overload. Mechanistically, FAK overexpression resulted in enhanced myocardial FAK activity, which was proven by treatment with a selective FAK inhibitor to be required for the cardiac hypertrophy in this model. Our results indicate that upregulation of FAK does not affect the activity of Src/ERK1/2 pathway, but stimulated signaling by a cascade that encompasses PI3K, AKT, mTOR, S6K and rpS6. Moreover, inhibition of the mTOR complex by rapamycin extinguished the cardiac hypertrophy of the transgenic FAK mice. These findings uncover a unique role for FAK in regulating the signaling mechanisms that governs the selective myocyte growth in width, likely controlling the activity of PI3K/AKT/mTOR pathway, and suggest that FAK activation could be important for the adaptive response to increases in cardiac afterload. This article is part of a Special Issue entitled "Local Signaling in Myocytes".
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Affiliation(s)
- C F M Z Clemente
- Brazilian National Laboratory for Biosciences, Brazilian Association for Synchrotron Light Technology, Campinas, SP, Brazil
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Mutharasan RK, Nagpal V, Ichikawa Y, Ardehali H. microRNA-210 is upregulated in hypoxic cardiomyocytes through Akt- and p53-dependent pathways and exerts cytoprotective effects. Am J Physiol Heart Circ Physiol 2011; 301:H1519-30. [PMID: 21841015 DOI: 10.1152/ajpheart.01080.2010] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
microRNA-210 (miR-210) is upregulated in hypoxia, but its function in cardiomyocytes and its regulation in response to hypoxia are not well characterized. The purpose of this study was to identify upstream regulators of miR-210, as well as to characterize miR-210's function in cardiomyocytes. We first showed miR-210 is upregulated through both hypoxia-inducible factor (HIF)-dependent and -independent pathways, since aryl hydrocarbon nuclear translocator (ARNT) knockout mouse embryonic fibroblasts (MEF), lacking intact HIF signaling, still displayed increased miR-210 levels in hypoxia. To determine the mechanism for HIF-independent regulation of miR-210, we focused on p53 and protein kinase B (Akt). Overexpression of p53 in wild-type MEFs induced miR-210, whereas p53 overexpression in ARNT knockout MEFs did not, suggesting p53 regulates miR-210 in a HIF-dependent mechanism. Akt inhibition reduced miR-210 induction by hypoxia, whereas Akt overexpression increased miR-210 levels in both wild-type and ARNT knockout MEFs, indicating Akt regulation of miR-210 is HIF-independent. We then studied the effects of miR-210 in cardiomyocytes. Overexpression of miR-210 reduced cell death in response to oxidative stress and reduced reactive oxygen species (ROS) production both at baseline and after treatment with antimycin A. Furthermore, downregulation of miR-210 increased ROS after hypoxia-reoxygenation. To determine a mechanism for the cytoprotective effects of miR-210, we focused on the predicted target, apoptosis-inducing factor, mitochondrion-associated 3 (AIFM3), known to induce cell death. Although miR-210 reduced AIFM3 levels, overexpression of AIFM3 in the presence of miR-210 overexpression did not reduce cellular viability either at baseline or after hydrogen peroxide treatment, suggesting AIFM3 does not mediate miR-210's cytoprotective effects. Furthermore, HIF-3α, a negative regulator of HIF signaling, is targeted by miR-210, but miR-210 does not modulate HIF activity. In conclusion, we demonstrate a novel role for p53 and Akt in regulating miR-210 and demonstrate that, in cardiomyocytes, miR-210 exerts cytoprotective effects, potentially by reducing mitochondrial ROS production.
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Affiliation(s)
- R Kannan Mutharasan
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, Illinois 60611, USA
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27
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Markou T, Barlaka E, Bartucci M, Lazou A. Signal transduction pathways through cytoprotective, apoptotic and hypertrophic stimuli: a comparative study in adult cardiac myocytes. Cell Biochem Funct 2011; 29:442-51. [PMID: 21751224 DOI: 10.1002/cbf.1770] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 04/07/2011] [Accepted: 05/17/2011] [Indexed: 01/13/2023]
Abstract
In response to pathophysiological stresses, cardiac myocytes undergo hypertrophic growth or apoptosis. Multiple signalling pathways have been implicated in these responses and among them, kinases such as mitogen-activated protein kinases (MAPKs) and Akt. However, the distinction between signalling pathways originally believed to be specific for either hypertrophy, apoptosis or cell survival is fading. The existing data, coming from different experimental systems, often are conflicting. In this study, we sought to compare aspects of intracellular signalling activated by diverse stimuli in a single experimental system, adult rat cardiac myocytes. Furthermore, we assessed the role of these stimuli in eliciting a particular cell phenotype, i.e. whether they promote hypertrophy, cell survival or apoptosis. The results demonstrate that the hypertrophic agonist phenylephrine is the most potent activator of MAPKs/mitogen and stress- activated kinase MSK1, although its effect on Akt phosphorylation is relatively minor. The pro-apoptotic concentration of H₂O₂ activates strongly both MAPKs and PI3K/Akt pathways. Insulin-like growth factor-1 has a minimal effect on phosphorylation of MAPKs/MSK1, but it is a potent activator of Akt. In conclusion, hypertrophic, pro-survival or apoptotic stimuli operate through the same signalling pathways with different time course and amplitude of kinase activation. Thus, to determine the effect of different stimuli on cell fate, it is important to assess signalling pathways as a network and not as a single pathway.
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Affiliation(s)
- Thomais Markou
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
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28
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Yamamoto S, Iyoda T, Kita S, Yamada T, Iwamoto T. OSU-03012, a novel celecoxib derivative, induces cell swelling and shortens action potential duration in mouse ventricular cells. ACTA ACUST UNITED AC 2011; 31:413-7. [PMID: 21187652 DOI: 10.2220/biomedres.31.413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OSU03012, a novel celecoxib derivative, has been shown to inhibit proliferation and induce apoptosis in numerous cancer cell lines. However, not much is known about its influence on cell volume regulation and cardiac function in the mammalian heart. We examined the effects of OSU-03012 on cell volume and action potentials in mouse ventricular cells. Video image analysis showed that cell volume increased on application of OSU-03012 in a dose-dependent manner. The action potential duration (APD) at 50% and 90% repolarization (APD(50) and APD(90) respectively) as well as the resting membrane potential (RMP) were measured in current-clamp experiments. OSU-03012 had little effect on APD(50) and RMP but induced approximately 30% shortening of APD(90). These results for cell volume and AP are similar to those in cells under ischaemia/hypoxia, and we confirmed that the shortening of APD(90) was almost completely recovered by glibenclamide, a potent inhibitor of ATP-sensitive potassium channels.We concluded that OSU-03012 may lead to cell swelling and shortening of AP via reduced ATP production in mouse ventricular cells.
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Affiliation(s)
- Shintaro Yamamoto
- Department of Pharmacology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jyonan-ku, Fukuoka, Japan.
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Xie Y, Awonuga AO, Zhou S, Puscheck EE, Rappolee DA. Interpreting the stress response of early mammalian embryos and their stem cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 287:43-95. [PMID: 21414586 DOI: 10.1016/b978-0-12-386043-9.00002-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This review analyzes and interprets the normal, pathogenic, and pathophysiological roles of stress and stress enzymes in mammalian development. Emerging data suggest that stem cells from early embryos are induced by stress to perform stress-enzyme-mediated responses that use the strategies of compensatory, prioritized, and reversible differentiation. These strategies have been optimized during evolution and in turn have aspects of energy conservation during stress that optimize and maximize the efficacy of the stress response. It is likely that different types of stem cells have varying degrees of flexibility in mediating compensatory and prioritized differentiation. The significance of this analysis and interpretation is that it will serve as a foundation for yielding tools for diagnosing, understanding normal and pathophysiological mechanisms, and providing methods for managing stress enzymes to improve short- and long-term reproductive outcomes.
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Affiliation(s)
- Y Xie
- CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, USA
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30
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Catalucci D, Latronico MVG, Ceci M, Rusconi F, Young HS, Gallo P, Santonastasi M, Bellacosa A, Brown JH, Condorelli G. Akt increases sarcoplasmic reticulum Ca2+ cycling by direct phosphorylation of phospholamban at Thr17. J Biol Chem 2009; 284:28180-28187. [PMID: 19696029 DOI: 10.1074/jbc.m109.036566] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cardiomyocytes adapt to physical stress by increasing their size while maintaining cell function. The serine/threonine kinase Akt plays a critical role in this process of adaptation. We previously reported that transgenic overexpression of an active form of Akt (Akt-E40K) in mice results in increased cardiac contractility and cell size, as well as improved sarcoplasmic reticulum (SR) Ca(2+) handling. Because it is not fully elucidated, we decided to study the molecular mechanism by which Akt-E40K overexpression improves SR Ca(2+) handling. To this end, SR Ca(2+) uptake and the phosphorylation status of phospholamban (PLN) were evaluated in heart extracts from wild-type and Akt-E40K mice and mice harboring inducible and cardiac specific knock-out of phosphatidylinositol-dependent kinase-1, the upstream activator of Akt. Moreover, the effect of Akt was assessed in vitro by overexpressing a mutant Akt targeted preferentially to the SR, and by biochemical assays to evaluate potential interaction with PLN. We found that when activated, Akt interacts with and phosphorylates PLN at Thr(17), the Ca(2+)-calmodulin-dependent kinase IIdelta site, whereas silencing Akt signaling, through the knock-out of phosphatidylinositol-dependent kinase-1, resulted in reduced phosphorylation of PLN at Thr(17). Furthermore, overexpression of SR-targeted Akt in cardiomyocytes improved Ca(2+) handling without affecting cell size. Thus, we describe here a new mechanism whereby the preferential translocation of Akt to the SR is responsible for enhancement of contractility without stimulation of hypertrophy.
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Affiliation(s)
- Daniele Catalucci
- Istituto di Ricovero e Cura a Carattere Scientifico Multimedica, Milan 20138, Italy; Istituto Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Segrate, Milan 20090, Italy; Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla, California 92093.
| | | | - Marcello Ceci
- Istituto di Ricovero e Cura a Carattere Scientifico Multimedica, Milan 20138, Italy
| | - Francesca Rusconi
- Istituto di Ricovero e Cura a Carattere Scientifico Multimedica, Milan 20138, Italy; Istituto Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Segrate, Milan 20090, Italy
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Paolo Gallo
- Istituto di Ricovero e Cura a Carattere Scientifico Multimedica, Milan 20138, Italy
| | - Marco Santonastasi
- Istituto di Ricovero e Cura a Carattere Scientifico Multimedica, Milan 20138, Italy
| | | | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Gianluigi Condorelli
- Istituto di Ricovero e Cura a Carattere Scientifico Multimedica, Milan 20138, Italy; Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla, California 92093; Istituto Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Segrate, Milan 20090, Italy.
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Foletti A, Lisi A, Ledda M, de Carlo F, Grimaldi S. Cellular ELF Signals as a Possible Tool in Informative Medicine. Electromagn Biol Med 2009; 28:71-9. [DOI: 10.1080/15368370802708801] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Catalucci D, Zhang DH, DeSantiago J, Aimond F, Barbara G, Chemin J, Bonci D, Picht E, Rusconi F, Dalton ND, Peterson KL, Richard S, Bers DM, Brown JH, Condorelli G. Akt regulates L-type Ca2+ channel activity by modulating Cavalpha1 protein stability. ACTA ACUST UNITED AC 2009; 184:923-33. [PMID: 19307602 PMCID: PMC2699149 DOI: 10.1083/jcb.200805063] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The insulin IGF-1–PI3K–Akt signaling pathway has been suggested to
improve cardiac inotropism and increase Ca2+ handling through
the effects of the protein kinase Akt. However, the underlying molecular
mechanisms remain largely unknown. In this study, we provide evidence for an
unanticipated regulatory function of Akt controlling L-type Ca2+
channel (LTCC) protein density. The pore-forming channel subunit
Cavα1 contains highly conserved PEST sequences (signals for
rapid protein degradation), and in-frame deletion of these PEST sequences
results in increased Cavα1 protein levels. Our findings show
that Akt-dependent phosphorylation of Cavβ2, the LTCC chaperone
for Cavα1, antagonizes Cavα1 protein
degradation by preventing Cavα1 PEST sequence recognition,
leading to increased LTCC density and the consequent modulation of
Ca2+ channel function. This novel mechanism by which Akt
modulates LTCC stability could profoundly influence cardiac myocyte
Ca2+ entry, Ca2+ handling, and
contractility.
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Affiliation(s)
- Daniele Catalucci
- Division of Cardiology, Department of Medicine, University of California-San Diego, La Jolla, CA 92093, USA.
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33
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Ito M, Kodama M, Tsumanuma I, Ramadan MM, Hirayama S, Kamimura T, Kashimura T, Fuse K, Hirono S, Okura Y, Aizawa Y. Relationship between insulin-like growth factor-I and brain natriuretic peptide in patients with acromegaly after surgery. Circ J 2008; 71:1955-7. [PMID: 18037753 DOI: 10.1253/circj.71.1955] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Increased cardiac insulin-like growth factor (IGF)-I production is associated with physiological cardiac hypertrophy in athletes, and IGF-I has been recognized as a cardioprotective agent in experimental animal studies. On the other hand, acromegaly which is characterized by an excess of IGF-I has been linked to impaired cardiac function. METHODS AND RESULTS Both the relationship between the serum levels of IGF-I and brain natriuretic peptide (BNP), which is released from the cardiac ventricles in response to ventricular stress, and that between IGF-I and the concentrations of the plasma amino-terminal propeptide of procollagen type III (P-III-P), which is associated with myocardial fibrosis, were evaluated in 19 patients after surgical treatment for acromegaly. Echocardiography revealed that left ventricular systolic function and dimensions were within normal range in all patients. Significant inverse correlations were found between IGF-I and the BNP (r=-0.5, p=0.02) and P-III-P levels (r=-0.62, p=0.005). CONCLUSION We observed an inverse significant relationship between IGF-I and both the BNP and P-III-P value in surgically treated acromegaly patients. These observations suggest that appropriate levels of IGF-I have beneficial cardioprotective effects after surgery in patients with acromegaly.
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Affiliation(s)
- Masahiro Ito
- Division of Cardiology, Department of Neurosurgery, Brain Institute, Niigata University School of Medicine, Japan.
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Kemi OJ, Ceci M, Wisloff U, Grimaldi S, Gallo P, Smith GL, Condorelli G, Ellingsen O. Activation or inactivation of cardiac Akt/mTOR signaling diverges physiological from pathological hypertrophy. J Cell Physiol 2007; 214:316-21. [PMID: 17941081 DOI: 10.1002/jcp.21197] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cardiomyocyte hypertrophy differs according to the stress exerted on the myocardium. While pressure overload-induced cardiomyocyte hypertrophy is associated with depressed contractile function, physiological hypertrophy after exercise training associates with preserved or increased inotropy. We determined the activation state of myocardial Akt signaling with downstream substrates and fetal gene reactivation in exercise-induced physiological and pressure overload-induced pathological hypertrophies. C57BL/6J mice were either treadmill trained for 6 weeks, 5 days/week, at 85-90% of maximal oxygen uptake (VO(2max)), or underwent transverse aortic constriction (TAC) for 1 or 8 weeks. Total and phosphorylated protein levels were determined with SDS-PAGE, and fetal genes by real-time RT-PCR. In the physiologically hypertrophied heart after exercise training, total Akt protein level was unchanged, but Akt was chronically hyperphosphorylated at serine 473. This was accompanied by activation of the mammalian target of rapamycin (mTOR), measured as phosphorylation of its two substrates: the ribosomal protein S6 kinase-1 (S6K1) and the eukaryotic translation initiation factor-4E binding protein-1 (4E-BP1). Exercise training did not reactivate the fetal gene program (beta-myosin heavy chain, atrial natriuretic factor, skeletal muscle actin). In contrast, pressure overload after TAC reactivated fetal genes already after 1 week, and partially inactivated the Akt/mTOR pathway and downstream substrates after 8 weeks. In conclusion, changes in opposite directions of the myocardial Akt/mTOR signal pathway appears to distinguish between physiological and pathological hypertrophies; exercise training associating with activation and pressure overload associating with inactivation of the Akt/mTOR pathway.
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Affiliation(s)
- Ole Johan Kemi
- Institute of Biomedical and Life Sciences, University of Glasgow, UK.
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35
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Liu L, Zhao X, Pierre SV, Askari A. Association of PI3K-Akt signaling pathway with digitalis-induced hypertrophy of cardiac myocytes. Am J Physiol Cell Physiol 2007; 293:C1489-97. [PMID: 17728397 DOI: 10.1152/ajpcell.00158.2007] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous studies on cardiac myocytes showed that positive inotropic concentrations of the digitalis drug ouabain activated signaling pathways linked to Na(+)-K(+)-ATPase through Src and epidermal growth factor receptor (EGFR) and led to myocyte hypertrophy. In view of the known involvement of phosphatidylinositol 3-kinase (PI3K)-Akt pathways in cardiac hypertrophy, the aim of the present study was to determine whether these pathways are also linked to cardiac Na(+)-K(+)-ATPase and, if so, to assess their role in ouabain-induced myocyte growth. In a dose- and time-dependent manner, ouabain activated Akt and phosphorylation of its substrates mammalian target of rapamycin and glycogen synthase kinase in neonatal rat cardiac myocytes. Akt activation by ouabain was sensitive to PI3K inhibitors and was also noted in adult myocytes and isolated hearts. Ouabain caused a transient increase of phosphatidylinositol 3,4,5-trisphosphate content of neonatal myocytes, activated class IA, but not class IB, PI3K, and increased coimmunoprecipitation of the alpha-subunit of Na(+)-K(+)-ATPase with the p85 subunit of class IA PI3K. Ouabain-induced activation of ERK1/2 was prevented by Src, EGFR, and MEK inhibitors, but not by PI3K inhibitors. Activation of Akt by ouabain, however, was sensitive to inhibitors of PI3K and Src, but not to inhibitors of EGFR and MEK. Similarly, ouabain-induced myocyte hypertrophy was prevented by PI3K and Src inhibitors, but not by an EGFR inhibitor. These findings 1) establish the linkage of the class IA PI3K-Akt pathway to Na(+)-K(+)-ATPase and the essential role of this linkage to ouabain-induced myocyte hypertrophy and 2) suggest cross talk between these PI3K-Akt pathways and the signaling cascades previously identified to be associated with cardiac Na(+)-K(+)-ATPase.
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Affiliation(s)
- Lijun Liu
- Department of Physiology, Pharmacology, Metabolism, and Cardiovascular Sciences, The University of Toledo College of Medicine, Toledo, Ohio 43614-2598, USA
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36
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van de Schans VAM, van den Borne SWM, Strzelecka AE, Janssen BJA, van der Velden JLJ, Langen RCJ, Wynshaw-Boris A, Smits JFM, Blankesteijn WM. Interruption of Wnt signaling attenuates the onset of pressure overload-induced cardiac hypertrophy. Hypertension 2007; 49:473-80. [PMID: 17210832 DOI: 10.1161/01.hyp.0000255946.55091.24] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The hypertrophic response of the heart has been recognized recently as the net result of activation of prohypertrophic and antihypertrophic pathways. Here we report the involvement of the Wnt/Frizzled pathway in the onset of cardiac hypertrophy development. Stimulation of the Wnt/Frizzled pathway activates the disheveled (Dvl) protein. Disheveled subsequently can inhibit glycogen synthase kinase-3beta, a protein with potent antihypertrophic actions through diverse molecular mechanisms. In the Wnt/Frizzled pathway, inhibition of glycogen synthase kinase-3beta leads to an increased amount of beta-catenin, which can act as a transcription factor for several hypertrophy-associated target genes. In this study we subjected mice lacking the Dvl-1 gene and their wild-type littermates to thoracic aortic constriction for 7, 14, and 35 days. In mice lacking the Dvl-1 gene, 7 days of pressure overload-induced increases in left ventricular posterior wall thickness and expression of atrial natriuretic factor and brain natriuretic protein were attenuated compared with their wild-type littermates. Beta-catenin protein amount was reduced in the group lacking the Dvl-1 gene, and an increased glycogen synthase kinase-3beta activity was observed. Moreover, the increase in the amount of Ser(473)-phosphorylated Akt, a stimulator of cardiac hypertrophy, was lower in the group lacking the Dvl-1 gene. In conclusion, we have demonstrated that interruption of Wnt signaling in the mice lacking the Dvl-1 gene attenuates the onset of pressure overload-induced cardiac hypertrophy through mechanisms involving glycogen synthase kinase-3beta and Akt. Therefore, the Wnt/Frizzled pathway may provide novel therapeutic targets for antihypertrophic therapy.
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Affiliation(s)
- Veerle A M van de Schans
- Department of Pharmacology and Toxicology, Cardiovascular Research Institute Maastricht, Maastricht University, The Netherlands
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Sharma N, Okere IC, Duda MK, Chess DJ, O'Shea KM, Stanley WC. Potential impact of carbohydrate and fat intake on pathological left ventricular hypertrophy. Cardiovasc Res 2006; 73:257-68. [PMID: 17166490 PMCID: PMC2700717 DOI: 10.1016/j.cardiores.2006.11.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 11/03/2006] [Accepted: 11/06/2006] [Indexed: 01/11/2023] Open
Abstract
Currently, a high carbohydrate/low fat diet is recommended for patients with hypertension; however, the potentially important role that the composition of dietary fat and carbohydrate plays in hypertension and the development of pathological left ventricular hypertrophy (LVH) has not been well characterized. Recent studies demonstrate that LVH can also be triggered by activation of insulin signaling pathways, altered adipokine levels, or the activity of peroxisome proliferator-activated receptors (PPARs), suggesting that metabolic alterations play a role in the pathophysiology of LVH. Hypertensive patients with high plasma insulin or metabolic syndrome have a greater occurrence of LVH, which could be due to insulin activation of the serine-threonine kinase Akt and its downstream targets in the heart, resulting in cellular hypertrophy. PPARs also activate cardiac gene expression and growth and are stimulated by fatty acids and consumption of a high fat diet. Dietary intake of fats and carbohydrate and the resultant effects of plasma insulin, adipokine, and lipid concentrations may affect cardiomyocyte size and function, particularly in the setting of chronic hypertension. This review discusses potential mechanisms by which dietary carbohydrates and fats ca affect cardiac growth, metabolism, and function, mainly in the context of pressure overload-induced LVH.
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Affiliation(s)
- Naveen Sharma
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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38
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Yun BG, Matts RL. Hsp90 functions to balance the phosphorylation state of Akt during C2C12 myoblast differentiation. Cell Signal 2006; 17:1477-85. [PMID: 15935620 DOI: 10.1016/j.cellsig.2005.03.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2005] [Revised: 02/15/2005] [Accepted: 03/03/2005] [Indexed: 01/16/2023]
Abstract
The function of the 90-kDa heat shock protein (Hsp90) is essential for the regulation of a myriad of signal transduction cascades that control all facets of a cell's physiology. Akt (PKB) is an Hsp90-dependent serine-threonine kinase that plays critical roles in the regulation of muscle cell physiology, including roles in the regulation of muscle differentiation and anti-apoptotic responses that modulate cell survival. In this report, we have examined the role of Hsp90 in regulating the activity of Akt in differentiating C2C12 myoblasts. While long-term treatment of differentiating C2C12 cells with the Hsp90 inhibitor geldanamycin led to the depletion of cellular Akt levels, pulse-chase analysis indicated that geldanamycin primarily enhanced the turnover rate of newly synthesized Akt. Hsp90 maintained an interaction with mature Akt, while Cdc37, Hsp90's kinase-specific co-chaperone, was lost from the chaperone complex upon Akt maturation. Geldanamycin partially disrupted the interaction of Cdc37 with Akt, but had a much less significant effect on the interaction of Hsp90 with Akt. Surprisingly, short-term treatment of differentiating C2C12 with geldanamycin increased the phosphorylation of Akt on Ser473, an effect mimicked by treatment of C2C12 cells with okadaic acid or the Hsp90 inhibitor novobiocin. Furthermore, Akt was found to interact directly with catalytic subunit of protein phosphatase 2A (PP2Ac) in C2C12 cells, and this interaction was not disrupted by geldanamycin. Thus, our findings indicate that Hsp90 functions to balance the phosphorylation state of Akt by modulating the ability of Akt to be dephosphorylated by PP2Ac during C2C12 myoblast differentiation.
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Affiliation(s)
- Bo-Geon Yun
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078-3035, United States
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Schiekofer S, Shiojima I, Sato K, Galasso G, Oshima Y, Walsh K. Microarray analysis of Akt1 activation in transgenic mouse hearts reveals transcript expression profiles associated with compensatory hypertrophy and failure. Physiol Genomics 2006; 27:156-70. [PMID: 16882883 DOI: 10.1152/physiolgenomics.00234.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To investigate molecular mechanisms involved in the development of cardiac hypertrophy and heart failure, we developed a tetracycline-regulated transgenic system to conditionally switch a constitutively active form of the Akt1 protein kinase on or off in the adult heart. Short-term activation (2 wk) of Akt1 resulted in completely reversible hypertrophy with maintained contractility. In contrast, chronic Akt1 activation (6 wk) induced extensive cardiac hypertrophy, severe contractile dysfunction, and massive interstitial fibrosis. The focus of this study was to create a transcript expression profile of the heart as it undergoes reversible Akt1-mediated hypertrophy and during the transition from compensated hypertrophy to heart failure. Heart tissue was analyzed before transgene induction, 2 wk after transgene induction, 2 wk of transgene induction followed by 2 days of repression, 6 wk after transgene induction, and 6 wk of transgene induction followed by 2 wk of repression. Acute overexpression of Akt1 (2 wk) leads to changes in the expression of 826 transcripts relative to noninduced hearts, whereas chronic induction (6 wk) led to changes in the expression of 1,611, of which 65% represented transcripts that were regulated during the pathological phase of heart growth. Another set of genes identified was uniquely regulated during heart regression but not growth, indicating that nonoverlapping transcription programs participate in the processes of cardiac hypertrophy and atrophy. These data define the gene regulatory programs downstream of Akt that control heart size and contribute to the transition from compensatory hypertrophy to heart failure.
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Affiliation(s)
- Stephan Schiekofer
- Molecular Cardiology/Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Gude N, Muraski J, Rubio M, Kajstura J, Schaefer E, Anversa P, Sussman MA. Akt promotes increased cardiomyocyte cycling and expansion of the cardiac progenitor cell population. Circ Res 2006; 99:381-8. [PMID: 16840722 DOI: 10.1161/01.res.0000236754.21499.1c] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of Akt is associated with enhanced cell cycling and cellular proliferation in nonmyocytes, but this effect of nuclear Akt accumulation has not been explored in the context of the myocardium. Cardiac-specific expression of nuclear-targeted Akt (Akt/nuc) in transgenics prolongs postnatal cell cycling as evidenced by increased numbers of Ki67+ cardiomyocytes at 2 to 3 weeks after birth. Similarly, nuclear-targeting of Akt promotes expansion of the presumptive cardiac progenitor cell population as assessed by immunolabeling for c-kit in combination with myocyte-specific markers Nkx 2.5 or MEF 2C. Increases in pro-proliferative cytokines, including tumor-necrosis superfamily 8, interleukin-17e, and hepatocyte growth factor, were found in nuclear-targeted Akt myocardial samples. Concurrent signaling mediated by paracrine factors downstream of Akt/nuc expression may be responsible for phenotypic effects of nuclear-targeted Akt in the myocardium, including enhanced cell proliferation and expansion of the stem cell population.
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Affiliation(s)
- Natalie Gude
- San Diego State University Heart Institute and Department of Biology, San Diego State University, San Diego, CA 92182, USA
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Yun BG, Matts RL. Differential effects of Hsp90 inhibition on protein kinases regulating signal transduction pathways required for myoblast differentiation. Exp Cell Res 2005; 307:212-23. [PMID: 15922741 DOI: 10.1016/j.yexcr.2005.03.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2004] [Revised: 02/25/2005] [Accepted: 03/01/2005] [Indexed: 12/27/2022]
Abstract
As derivatives of the Hsp90-inhibitor and tumoricidal agent geldanamycin move into phase II clinical trials, its potential for triggering adverse effects in non-tumor cell populations requires closer examination. In this report, the effect of geldanamycin on the differentiation and survival of C2C12 myoblasts was investigated. Treatment of differentiating C2C12 myoblasts with geldanamycin blocked myogenin expression, inhibited myotubule formation, and led to the depletion of three Hsp90-dependent protein kinases, ErbB2, Fyn, and Akt, and induction of apoptosis. ErbB2 levels declined rapidly, while Fyn and Akt levels decreased at a slower rate. Geldanamycin blocked the interaction of Hsp90 and its "kinase-specific" co-chaperone Cdc37 with Fyn, indicating that Fyn is an Hsp90-dependent kinase. Pulse-chase experiments indicated that geldanamycin caused newly synthesized Akt and Fyn to be degraded rapidly, but geldanamycin had little effect on the turnover rate of mature Fyn and Akt. Curiously, total cellular Src (c-Src) protein levels and the turnover rate of newly synthesized c-Src were unaffected by geldanamycin. While, geldanamycin had no effect on the levels of the putative Hsp90 client protein MyoD expressed in C2C12 cells, geldanamycin disrupted the interaction of Cdc37 with MyoD. Thus, inhibition of Hsp90 caused C2C12 cells to become depleted of multiple signal transduction proteins whose functions are essential for myoblast differentiation, and muscle cell survival, suggesting that geldanamycin derivatives may have the prospective of adversely affecting the physiology of certain sensitive muscle cell populations in vivo.
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Affiliation(s)
- Bo-Geon Yun
- Department of Biochemistry and Molecular Biology, 246 NRC, Oklahoma State University, Stillwater, OK 74078-3035, USA
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