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Gunasekaran M, Littel HR, Wells NM, Turner J, Campos G, Venigalla S, Estrella EA, Ghosh PS, Daugherty AL, Stafki SA, Kunkel LM, Foley AR, Donkervoort S, Bönnemann CG, Toledo-Bravo de Laguna L, Nascimento A, Benito DND, Draper I, Bruels CC, Pacak CA, Kang PB. Effects of HMGCR deficiency on skeletal muscle development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.591934. [PMID: 38903061 PMCID: PMC11188090 DOI: 10.1101/2024.05.06.591934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Pathogenic variants in HMGCR were recently linked to a limb-girdle muscular dystrophy (LGMD) phenotype. The protein product HMG CoA reductase (HMGCR) catalyzes a key component of the cholesterol synthesis pathway. The two other muscle diseases associated with HMGCR, statin-associated myopathy (SAM) and autoimmune anti-HMGCR myopathy, are not inherited in a Mendelian pattern. The mechanism linking pathogenic variants in HMGCR with skeletal muscle dysfunction is unclear. We knocked down Hmgcr in mouse skeletal myoblasts, knocked down hmgcr in Drosophila, and expressed three pathogenic HMGCR variants (c.1327C>T, p.Arg443Trp; c.1522_1524delTCT, p.Ser508del; and c.1621G>A, p.Ala541Thr) in Hmgcr knockdown mouse myoblasts. Hmgcr deficiency was associated with decreased proliferation, increased apoptosis, and impaired myotube fusion. Transcriptome sequencing of Hmgcr knockdown versus control myoblasts revealed differential expression involving mitochondrial function, with corresponding differences in cellular oxygen consumption rates. Both ubiquitous and muscle-specific knockdown of hmgcr in Drosophila led to lethality. Overexpression of reference HMGCR cDNA rescued myotube fusion in knockdown cells, whereas overexpression of the pathogenic variants of HMGCR cDNA did not. These results suggest that the three HMGCR-related muscle diseases share disease mechanisms related to skeletal muscle development.
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Ahmadi Y, Fard JK, Ghafoor D, Eid AH, Sahebkar A. Paradoxical effects of statins on endothelial and cancer cells: the impact of concentrations. Cancer Cell Int 2023; 23:43. [PMID: 36899388 PMCID: PMC9999585 DOI: 10.1186/s12935-023-02890-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 03/04/2023] [Indexed: 03/12/2023] Open
Abstract
In addition to their lipid-lowering functions, statins elicit additional pleiotropic effects on apoptosis, angiogenesis, inflammation, senescence, and oxidative stress. Many of these effects have been reported in cancerous and noncancerous cells like endothelial cells (ECs), endothelial progenitor cells (EPCs) and human umbilical vein cells (HUVCs). Not surprisingly, statins' effects appear to vary largely depending on the cell context, especially as pertains to modulation of cell cycle, senescence, and apoptotic processes. Perhaps the most critical reason for this discordance is the bias in selecting the applied doses in various cells. While lower (nanomolar) concentrations of statins impose anti-senescence, and antiapoptotic effects, higher concentrations (micromolar) appear to precipitate opposite effects. Indeed, most studies performed in cancer cells utilized high concentrations, where statin-induced cytotoxic and cytostatic effects were noted. Some studies report that even at low concentrations, statins induce senescence or cytostatic impacts but not cytotoxic effects. However, the literature appears to be relatively consistent that in cancer cells, statins, in both low or higher concentrations, induce apoptosis or cell cycle arrest, anti-proliferative effects, and cause senescence. However, statins' effects on ECs depend on the concentrations; at micromolar concentrations statins cause cell senescence and apoptosis, while at nonomolar concentrations statins act reversely.
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Affiliation(s)
- Yasin Ahmadi
- College of Science, Department of Medical Laboratory Sciences, Komar University of Science and Technology, 46001, Sulaymania, Iraq.
| | - Javad Khalili Fard
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Dlzar Ghafoor
- College of Science, Department of Medical Laboratory Sciences, Komar University of Science and Technology, 46001, Sulaymania, Iraq
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. .,Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. .,Department of Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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Mollazadeh H, Tavana E, Fanni G, Bo S, Banach M, Pirro M, von Haehling S, Jamialahmadi T, Sahebkar A. Effects of statins on mitochondrial pathways. J Cachexia Sarcopenia Muscle 2021; 12:237-251. [PMID: 33511728 PMCID: PMC8061391 DOI: 10.1002/jcsm.12654] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/09/2020] [Accepted: 10/20/2020] [Indexed: 12/12/2022] Open
Abstract
Statins are a family of drugs that are used for treating hyperlipidaemia with a recognized capacity to prevent cardiovascular disease events. They inhibit β-hydroxy β-methylglutaryl-coenzyme A reductase, i.e. the rate-limiting enzyme in mevalonate pathway, reduce endogenous cholesterol synthesis, and increase low-density lipoprotein clearance by promoting low-density lipoprotein receptor expression mainly in the hepatocytes. Statins have pleiotropic effects including stabilization of atherosclerotic plaques, immunomodulation, anti-inflammatory properties, improvement of endothelial function, antioxidant, and anti-thrombotic action. Despite all beneficial effects, statins may elicit adverse reactions such as myopathy. Studies have shown that mitochondria play an important role in statin-induced myopathies. In this review, we aim to report the mechanisms of action of statins on mitochondrial function. Results have shown that statins have several effects on mitochondria including reduction of coenzyme Q10 level, inhibition of respiratory chain complexes, induction of mitochondrial apoptosis, dysregulation of Ca2+ metabolism, and carnitine palmitoyltransferase-2 expression. The use of statins has been associated with the onset of additional pathological conditions like diabetes and dementia as a result of interference with mitochondrial pathways by various mechanisms, such as reduction in mitochondrial oxidative phosphorylation, increase in oxidative stress, decrease in uncoupling protein 3 concentration, and interference in amyloid-β metabolism. Overall, data reported in this review suggest that statins may have major effects on mitochondrial function, and some of their adverse effects might be mediated through mitochondrial pathways.
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Affiliation(s)
- Hamid Mollazadeh
- Department of Physiology and Pharmacology, Faculty of MedicineNorth Khorasan University of Medical SciencesBojnurdIran
- Natural Products and Medicinal Plants Research CenterNorth Khorasan University of Medical SciencesBojnurdIran
| | - Erfan Tavana
- Student Research Committee, School of MedicineNorth Khorasan University of Medical SciencesBojnurdIran
| | - Giovanni Fanni
- Department of Medical SciencesUniversity of TurinTurinItaly
| | - Simona Bo
- Department of Medical Sciences, AOU Città della Salute e della Scienza di TorinoUniversity of TurinTurinItaly
| | - Maciej Banach
- Department of HypertensionWAM University Hospital in LodzMedical University of Lodz, LodzPoland
- Polish Mother's Memorial Hospital Research Institute (PMMHRI), LodzPoland
| | - Matteo Pirro
- Unit of Internal Medicine, Angiology and Arteriosclerosis Diseases, Department of MedicineUniversity of PerugiaPerugiaItaly
| | - Stephan von Haehling
- Department of Cardiology and PneumologyUniversity Medical Center GöttingenGöttingenGermany
- German Center for Cardiovascular Research (DZHK), partner site GöttingenGöttingenGermany
| | - Tannaz Jamialahmadi
- Department of Food Science and TechnologyIslamic Azad UniversityQuchanQuchanIran
- Department of Nutrition, Faculty of MedicineMashhad University of Medical SciencesMashhadIran
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology InstituteMashhad University of Medical SciencesMashhadIran
- Neurogenic Inflammation Research CenterMashhad University of Medical SciencesMashhadIran
- Halal Research Center of IRIFDATehranIran
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The effects of statins with a high hepatoselectivity rank on the extra-hepatic tissues; New functions for statins. Pharmacol Res 2019; 152:104621. [PMID: 31891788 DOI: 10.1016/j.phrs.2019.104621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 12/26/2019] [Indexed: 12/14/2022]
Abstract
Statins, as the most common treatment for hyperlipidemia, exert effects beyond their lipid-lowering role which are known as pleiotropic effects. These effects are mainly due to the inhibition of isoprenoids synthesis and consequently blocking prenylation of proteins involved in the cellular signaling pathways regulating cell development, growth, and apoptosis. Statins target cholesterol synthesis in the liver as the major source of cholesterol in the body and so reduce whole-body cholesterol. The reduced level of cholesterol forces other organs to an adaptive homeostatic reaction to increase their cholesterol synthesis capacity, however, this only occurs when statins have unremarkable access to the extra-hepatic tissues. In order to reduce the adverse effects of statin on the skeletal muscle, most recent efforts have been towards formulating new statins with the highest level of hepatoselectivity rank and the least level of access to the extra-hepatic tissues; however, the inaccessibility of statins for the extra-hepatic tissues may induce several biological reactions. In this review, we aim to evaluate the effects of statins on the extra-hepatic tissues when statins have unremarkable access to these tissues.
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Chung HR, Vakil M, Munroe M, Parikh A, Meador BM, Wu PT, Jeong JH, Woods JA, Wilund KR, Boppart MD. The Impact of Exercise on Statin-Associated Skeletal Muscle Myopathy. PLoS One 2016; 11:e0168065. [PMID: 27936249 PMCID: PMC5148116 DOI: 10.1371/journal.pone.0168065] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/23/2016] [Indexed: 01/07/2023] Open
Abstract
HMG-CoA reductase inhibitors (statins) are the most effective pharmacological means of reducing cardiovascular disease risk. The most common side effect of statin use is skeletal muscle myopathy, which may be exacerbated by exercise. Hypercholesterolemia and training status are factors that are rarely considered in the progression of myopathy. The purpose of this study was to determine the extent to which acute and chronic exercise can influence statin-induced myopathy in hypercholesterolemic (ApoE-/-) mice. Mice either received daily injections of saline or simvastatin (20 mg/kg) while: 1) remaining sedentary (Sed), 2) engaging in daily exercise for two weeks (novel, Nov), or 3) engaging in daily exercise for two weeks after a brief period of training (accustomed, Acct) (2x3 design, n = 60). Cholesterol, activity, strength, and indices of myofiber damage and atrophy were assessed. Running wheel activity declined in both exercise groups receiving statins (statin x time interaction, p<0.05). Cholesterol, grip strength, and maximal isometric force were significantly lower in all groups following statin treatment (statin main effect, p<0.05). Mitochondrial content and myofiber size were increased and 4-HNE was decreased by exercise (statin x exercise interaction, p<0.05), and these beneficial effects were abrogated by statin treatment. Exercise (Acct and Nov) increased atrogin-1 mRNA in combination with statin treatment, yet enhanced fiber damage or atrophy was not observed. The results from this study suggest that exercise (Nov, Acct) does not exacerbate statin-induced myopathy in ApoE-/- mice, yet statin treatment reduces activity in a manner that prevents muscle from mounting a beneficial adaptive response to training.
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Affiliation(s)
- Hae R. Chung
- Renal and Cardiovascular Disease Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Mayand Vakil
- Renal and Cardiovascular Disease Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Michael Munroe
- Molecular Muscle Physiology Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Alay Parikh
- Molecular Muscle Physiology Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Benjamin M. Meador
- Renal and Cardiovascular Disease Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Pei T. Wu
- Renal and Cardiovascular Disease Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jin H. Jeong
- Renal and Cardiovascular Disease Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jeffrey A. Woods
- Exercise Immunology Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Kenneth R. Wilund
- Renal and Cardiovascular Disease Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Marni D. Boppart
- Molecular Muscle Physiology Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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Bouitbir J, Singh F, Charles AL, Schlagowski AI, Bonifacio A, Echaniz-Laguna A, Geny B, Krähenbühl S, Zoll J. Statins Trigger Mitochondrial Reactive Oxygen Species-Induced Apoptosis in Glycolytic Skeletal Muscle. Antioxid Redox Signal 2016; 24:84-98. [PMID: 26414931 DOI: 10.1089/ars.2014.6190] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS Although statins are the most widely used cholesterol-lowering agents, they are associated with a variety of muscle complaints. The goal of this study was to characterize the effects of statins on the mitochondrial apoptosis pathway induced by mitochondrial oxidative stress in skeletal muscle using human muscle biopsies as well as in vivo and in vitro models. RESULTS Statins increased mitochondrial H2O2 production, the Bax/Bcl-2 ratio, and TUNEL staining in deltoid biopsies of patients with statin-associated myopathy. Furthermore, atorvastatin treatment for 2 weeks at 10 mg/kg/day in rats increased H2O2 accumulation and mRNA levels and immunostaining of the Bax/Bcl-2 ratio, as well as TUNEL staining and caspase 3 cleavage in glycolytic (plantaris) skeletal muscle, but not in oxidative (soleus) skeletal muscle, which has a high antioxidative capacity. Atorvastatin also decreased the GSH/GSSG ratio, but only in glycolytic skeletal muscle. Cotreatment with the antioxidant, quercetin, at 25 mg/kg/day abolished these effects in plantaris. An in vitro study with L6 myoblasts directly demonstrated the link between mitochondrial oxidative stress following atorvastatin exposure and activation of the mitochondrial apoptosis signaling pathway. INNOVATION Treatment with atorvastatin is associated with mitochondrial oxidative stress, which activates apoptosis and contributes to myopathy. Glycolytic muscles are more sensitive to atorvastatin than oxidative muscles, which may be due to the higher antioxidative capacity in oxidative muscles. CONCLUSION There is a link between statin-induced mitochondrial oxidative stress and activation of the mitochondrial apoptosis signaling pathway in glycolytic skeletal muscle, which may be associated with statin-associated myopathy.
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Affiliation(s)
- Jamal Bouitbir
- 1 Fédération de Médecine Translationelle, Faculté de Médecine, Institut de Physiologie, Université de Strasbourg , Strasbourg, France .,2 Service de Physiologie et d'Explorations Fonctionnelles, Pôle de Pathologie Thoracique, Hôpitaux Universitaires de Strasbourg , Strasbourg, France .,3 Swiss Centre for Applied Human Research (SCAHT) , Basel, Switzerland
| | - François Singh
- 1 Fédération de Médecine Translationelle, Faculté de Médecine, Institut de Physiologie, Université de Strasbourg , Strasbourg, France .,2 Service de Physiologie et d'Explorations Fonctionnelles, Pôle de Pathologie Thoracique, Hôpitaux Universitaires de Strasbourg , Strasbourg, France .,4 Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital , Basel, Switzerland
| | - Anne-Laure Charles
- 1 Fédération de Médecine Translationelle, Faculté de Médecine, Institut de Physiologie, Université de Strasbourg , Strasbourg, France
| | - Anna-Isabel Schlagowski
- 1 Fédération de Médecine Translationelle, Faculté de Médecine, Institut de Physiologie, Université de Strasbourg , Strasbourg, France .,2 Service de Physiologie et d'Explorations Fonctionnelles, Pôle de Pathologie Thoracique, Hôpitaux Universitaires de Strasbourg , Strasbourg, France
| | - Annalisa Bonifacio
- 4 Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital , Basel, Switzerland
| | | | - Bernard Geny
- 1 Fédération de Médecine Translationelle, Faculté de Médecine, Institut de Physiologie, Université de Strasbourg , Strasbourg, France .,2 Service de Physiologie et d'Explorations Fonctionnelles, Pôle de Pathologie Thoracique, Hôpitaux Universitaires de Strasbourg , Strasbourg, France
| | - Stephan Krähenbühl
- 3 Swiss Centre for Applied Human Research (SCAHT) , Basel, Switzerland .,4 Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital , Basel, Switzerland
| | - Joffrey Zoll
- 1 Fédération de Médecine Translationelle, Faculté de Médecine, Institut de Physiologie, Université de Strasbourg , Strasbourg, France .,2 Service de Physiologie et d'Explorations Fonctionnelles, Pôle de Pathologie Thoracique, Hôpitaux Universitaires de Strasbourg , Strasbourg, France
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Meador BM, Huey KA. Statin-associated changes in skeletal muscle function and stress response after novel or accustomed exercise. Muscle Nerve 2011; 44:882-9. [DOI: 10.1002/mus.22236] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Meador BM, Huey KA. Statin-associated myopathy and its exacerbation with exercise. Muscle Nerve 2010; 42:469-79. [DOI: 10.1002/mus.21817] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Many patients who receive statin therapy for hyperlipidemia-such as patients with diabetes mellitus and metabolic syndrome--have residual cardiovascular risk. These patients often have dyslipidemia, including low levels of HDL cholesterol and elevated levels of triglycerides and small, dense LDL. For such patients, combination treatment with statins and fibrates is a potentially useful strategy to improve lipid and lipoprotein profiles and reduce cardiovascular risk. However, statin-fibrate combination regimens have potential adverse effects on skeletal muscle, including myopathy. To date, no large-scale, prospective, randomized, controlled trial has evaluated the safety and efficacy of statin-fibrate combination therapy; one such trial is underway but will not report data until 2010. Until then, clinicians need to consider pharmacokinetic, pharmacodynamic, metabolic, pathophysiologic and other factors that can increase the systemic exposure of statins and/or fibrates and hence heighten the risk of toxic effects on muscles, as well as data from clinical trials and recommendations of consensus panels to optimize the safety of such combination regimens. On the basis of currently available data, fenofibrate or fenofibric acid is the fibrate of choice when used in combination with a statin because each is, in theory, associated with a lower risk of myopathy than gemfibrozil.
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Affiliation(s)
- Terry A Jacobson
- Office of Health Promotion and Disease Prevention, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30303, USA.
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Gruzman A, Shamni O, Ben Yakir M, Sandovski D, Elgart A, Alpert E, Cohen G, Hoffman A, Katzhendler Y, Cerasi E, Sasson S. Novel D-xylose derivatives stimulate muscle glucose uptake by activating AMP-activated protein kinase alpha. J Med Chem 2009; 51:8096-108. [PMID: 19049348 DOI: 10.1021/jm8008713] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Type 2 diabetes mellitus has reached epidemic proportions; therefore, the search for novel antihyperglycemic drugs is intense. We have discovered that D-xylose increases the rate of glucose transport in a non-insulin-dependent manner in rat and human myotubes in vitro. Due to the unfavorable pharmacokinetic properties of D-xylose we aimed at synthesizing active derivatives with improved parameters. Quantitative structure-activity relationship analysis identified critical hydroxyl groups in D-xylose. These data were used to synthesize various hydrophobic derivatives of D-xylose of which compound 19 the was most potent compound in stimulating the rate of hexose transport by increasing the abundance of glucose transporter-4 in the plasma membrane of myotubes. This effect resulted from the activation of AMP-activated protein kinase without recruiting the insulin transduction mechanism. These results show that lipophilic D-xylose derivatives may serve as prototype molecules for the development of novel antihyperglycemic drugs for the treatment of diabetes.
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Affiliation(s)
- Arie Gruzman
- Department of Pharmacology, School of Pharmacy, Faculty of Medicine, The Hebrew University, 91120 Jerusalem, Israel
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Khan NA, Di Cello F, Stins M, Kim KS. Gp120-mediated cytotoxicity of human brain microvascular endothelial cells is dependent on p38 mitogen-activated protein kinase activation. J Neurovirol 2007; 13:242-51. [PMID: 17613714 DOI: 10.1080/13550280701286531] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Breakdown of the blood-brain barrier has been shown to contribute to neurological disorders that are prevalent in human immunodeficiency virus type 1 (HIV-1)-infected individuals, but the mechanisms involved in HIV-1-associated blood-brain barrier dysfunction remain incompletely understood. Using human brain microvascular endothelial cells (HBMECs) that constitute the blood-brain barrier, the authors determined the cytotoxic effects of gp120 on HBMECs. The authors showed that gp120 induced cytotoxicity of HBMECs derived from children, which required cotreatment with interferon (IFN)-gamma. IFN-gamma treatment exhibited up-regulation of the chemokine receptors CCR3 and CCR5 in children's HBMECs. In contrast, HBMECs isolated from adults were not responsive to gp120-mediated cytotoxicity. Peptides of gp120 representing binding regions for CD4 and chemokine receptors as well as CD4 antibody inhibited gp120-mediated cytotoxicity of HBMECs. RANTES, as expected, inhibited M-tropic gp120-mediated HBMEC cytotoxicity, whereas stromal cell-derived factor (SDF)-1alpha failed to inhibit T-tropic gp120-mediated cytotoxicity. Of interest, gp120 peptides representing non-CD4/non-chemokine receptor binding regions inhibited gp120-mediated HBMEC cytotoxicity. In addition, the authors showed that gp120-mediated HBMEC cytotoxicity involved p38 mitogen-activated protein kinase pathway. Taken together, these findings showed that gp120, in the presence of IFN-gamma, can cause dysfunction of the blood-brain barrier endothelium via MAPK pathways involving several gp120-HBMEC interactions.
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Affiliation(s)
- Naveed Ahmed Khan
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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Kim S, Kim Y, Lee Y, Cho KH, Kim KH, Chung JH. Cholesterol inhibits MMP-9 expression in human epidermal keratinocytes and HaCaT cells. FEBS Lett 2007; 581:3869-74. [PMID: 17643435 DOI: 10.1016/j.febslet.2007.06.074] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Revised: 06/18/2007] [Accepted: 06/28/2007] [Indexed: 12/01/2022]
Abstract
Cholesterol is a major component of skin lipids and acts as a regulator of vesicular trafficking and signal transduction. However, the function of cholesterol on matrix metalloproteinases (MMPs) expression of human skin is not fully understood. Here, we investigated the effects of cholesterol on MMP-9 expression in normal human keratinocytes (NHK) and HaCaT cells. Basal level of MMP-9 expression was decreased by cholesterol in NHK. On the other hand, MMP-9 expression was increased by the cholesterol depletion agent, methyl-beta-cyclodextrin (MbetaCD), while it was inhibited by cholesterol repletion in HaCaT cells. MbetaCD induced ERK and JNK phosphorylation were prevented by cholesterol repletion. The inhibition of ERK and JNK decreased MbetaCD-induced MMP-9 expression. Therefore, our results suggest that cholesterol regulates MMP-9 expression through ERK and JNK-dependent pathways.
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Affiliation(s)
- Sangmin Kim
- Department of Dermatology, Seoul National University College of Medicine, Laboratory of Cutaneous Aging Research, Clinical Research Institute, Seoul National University Hospital, Seoul 110-744, Republic of Korea
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Ogura T, Tanaka Y, Nakata T, Namikawa T, Kataoka H, Ohtsubo Y. Simvastatin reduces insulin-like growth factor-1 signaling in differentiating C2C12 mouse myoblast cells in an HMG-CoA reductase inhibition-independent manner. J Toxicol Sci 2007; 32:57-67. [PMID: 17327694 DOI: 10.2131/jts.32.57] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase occasionally cause myopathy characterized by weakness, pain, and elevated serum creatine phosphokinase (CK). In this study, we investigated the effects of simvastatin, an HMG-CoA reductase inhibitor, on the viability and insulin-like growth factor-1 (IGF-1) signaling in differentiating C2C12 mouse myoblast cells. Simvastatin decreased cell viability and CK activity, a marker of myogenesis, in differentiating cells in a dose-dependent manner. Although the simvastatin-induced decrease in viability in proliferating and differentiated cells was completely abolished by mevalonate or geranylgeranyl-pyrophosphate, the inhibitory effects of simvastatin in differentiating cells were not abolished by mevalonate or isoprenoid derivatives of mevalonate. Moreover, the sensitivity of differentiating cells to simvastatin regarding cell viability was about 7 times higher than that of proliferating cells. After induction of differentiation in the presence of 1 microM simvastatin for 2 days, IGF-1-induced activation of ERK1/2 and Akt was significantly decreased. Although mRNA expression of the IGF-1 receptor beta-chain (IGF-1R beta) did not change, protein level of the 200 kDa IGF-1Rbeta precursor was significantly increased by simvastatin in a dose-dependent manner. Mevalonate did not abolish the effect of simvastatin on IGF-1Rbeta expression. These results suggest that simvastatin decreases IGF-1 signaling via a regulation of the post-translational modification of IGF-1Rbeta in an HMG-CoA reductase inhibition-independent manner.
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Affiliation(s)
- Takeharu Ogura
- Biological Research Department, Sawai Pharmaceutical Co., Ltd., 5-2-30 Miyahara, Yodogawa-Ku, Osaka 532-0003, Japan.
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14
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Abstract
Over 100 million prescriptions were filled for statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) in 2004. Statins were originally developed to lower plasma cholesterol in patients with hypercholesterolemia and are the most effective drugs on the market in doing so. Because of the discovered pleiotropic effects of statins, the use has expanded to the treatment of many other conditions, including ventricular arrythmias, idiopathic dilated cardiomyopathy, cancer, osteoporosis, and diabetes. The elderly population is growing. Therefore, it is estimated that the number of statin users will also increase. Fortunately, the use of statins is relatively safe with few side effects. Myopathy is the most common side effect with symptoms ranging from fatigue, weakness, and pain to symptoms associated with rhabdomyolysis which is a life-threatening condition. The development of statin-induced rhabdomyolysis is rare occurring in approximately 0.1% of patients; however, the occurrence of less severe symptoms is underreported and may be 1-5% or more. Physical exercise appears to increase the likelihood for the development of myopathy in patients taking statins. It is thought that as many as 25% of statin users who exercise may experience muscle fatigue, weakness, aches, and cramping due to statin therapy and potentially dismissed by the patient and physician. The mechanisms causing statin-induced myopathy have not been elucidated; however, research efforts suggest that apoptosis of myofibers may contribute. The mitochondrion is considered a regulatory center of apoptosis, and therefore its role in the induction of apoptosis will be discussed as well as the mechanism of statin-induced apoptosis and myopathy.
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Affiliation(s)
- Amie J Dirks
- Wingate University School of Pharmacy, Wingate, North Carolina 28174, USA.
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15
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Sissons J, Kim KS, Stins M, Jayasekera S, Alsam S, Khan NA. Acanthamoeba castellanii induces host cell death via a phosphatidylinositol 3-kinase-dependent mechanism. Infect Immun 2005; 73:2704-8. [PMID: 15845472 PMCID: PMC1087316 DOI: 10.1128/iai.73.5.2704-2708.2005] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Granulomatous amoebic encephalitis due to Acanthamoeba castellanii is a serious human infection with fatal consequences, but it is not clear how the circulating amoebae interact with the blood-brain barrier and transmigrate into the central nervous system. We studied the effects of an Acanthamoeba encephalitis isolate belonging to the T1 genotype on human brain microvascular endothelial cells, which constitute the blood-brain barrier. Using an apoptosis-specific enzyme-linked immunosorbent assay, we showed that Acanthamoeba induces programmed cell death in brain microvascular endothelial cells. Next, we observed that Acanthamoeba specifically activates phosphatidylinositol 3-kinase. Acanthamoeba-mediated brain endothelial cell death was abolished using LY294002, a phosphatidylinositol 3-kinase inhibitor. These results were further confirmed using brain microvascular endothelial cells expressing dominant negative forms of phosphatidylinositol 3-kinase. This is the first demonstration that Acanthamoeba-mediated brain microvascular endothelial cell death is dependent on phosphatidylinositol 3-kinase.
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Affiliation(s)
- James Sissons
- School of Biological and Chemical Sciences, Birkbeck, College, University of London, London WC1E 7HX, England, United Kingdom
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16
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Sirvent P, Mercier J, Vassort G, Lacampagne A. Simvastatin triggers mitochondria-induced Ca2+ signaling alteration in skeletal muscle. Biochem Biophys Res Commun 2005; 329:1067-75. [PMID: 15752763 DOI: 10.1016/j.bbrc.2005.02.070] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Indexed: 11/22/2022]
Abstract
Statin drugs represent the major improvement in the treatment of hypercholesterolemia that constitutes the main origin of atherosclerosis, leading to coronary heart disease. Besides tremendous beneficial effects of statins, various forms of muscular toxicity (myalgia, cramp, exercise intolerance, and fatigability) occur frequently. We hypothesized that the iatrogenic effects of statins could result from alterations in Ca(2+) homeostasis. Acute applications of simvastatin on human skeletal muscle fibers triggered a Ca(2+) wave of intra-cellular Ca(2+) that mostly originates from sarcoplasmic reticulum (SR) Ca(2+)-release. In addition, simvastatin increased mitochondrial NADH content and induced mitochondrial membrane depolarization (EC(50)=1.96 microM) suggesting an altered mitochondrial function. Consequently on simvastatin application, a weak mitochondrial Ca(2+) efflux (EC(50)=7.8 microM) through permeability transient pore and Na(+)/Ca(2+) exchanger was triggered, preceding the large SR-Ca(2+) release. Increased SR Ca(2+) content after acute application of statin is also suggested by the increased Ca(2+) spark amplitude and by the effect of cyclopiazonic acid. We thus conclude that simvastatin induced alterations in mitochondrial function which lead to an increase in cytoplasmic Ca(2+), SR-Ca(2+) overload, and Ca(2+) waves. Taken together, these statin-induced muscle dysregulations may contribute to myotoxicity.
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Affiliation(s)
- Pascal Sirvent
- INSERM U637 CHU A. de Villeneuve, Montpellier, France; EA 701, Université Montpellier I, Montpellier, France
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17
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Cafforio P, Dammacco F, Gernone A, Silvestris F. Statins activate the mitochondrial pathway of apoptosis in human lymphoblasts and myeloma cells. Carcinogenesis 2005; 26:883-91. [PMID: 15705602 DOI: 10.1093/carcin/bgi036] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although statins are lipid-lowering drugs that block cholesterol biosynthesis, they exert immunomodulatory, anti-inflammatory, anti-angiogenic and anti-proliferative functions by reducing the isoprenylation of proteins involved in cell signal transduction such as Ras and RhoA. In this study, we provide evidence that several natural (lovastatin, simvastatin and pravastatin) and synthetic (cerivastatin and atorvastatin) statins exert a cytotoxic effect on human T, B and myeloma tumor cells by promoting their apoptosis. Dissimilar susceptibility to apoptosis has been detected in these lines, presumably in relation to the altered expression of proteins involved in the regulation of cellular signals. Cerivastatin promptly activated the cell death even in doxorubicin resistant cell lines such as MCC-2, whereas pravastatin, a hydrophilic compound, failed to induce any effect on either proliferation or apoptosis. The statin-induced apoptotic pathway in these cell lines was presumably regulated by altered prenylation of either Ras or RhoA, as measured by the defective membrane localization of these small GTPases. In addition the cell proliferation was rescued by both farnesylpyrophosphate (FPP) and geranyl-geranylpyrophosphate (GGPP), whereas no effect was obtained with squalene, a direct precursor of cholesterol. Statins primed apoptosis through its intrinsic pathway involving the mitochondria. In fact, we observed the reduction of mitochondrial membrane potential and the cytosolic release of the second mitochondria-derived activator of caspases (Smac/DIABLO). The apoptotic pathway was caspase-dependent since caspases 9, 3 and 8 were efficiently activated. These results support the potential use of statins in association with conventional treatment as apoptosis-triggering agents in these tumors.
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Affiliation(s)
- Paola Cafforio
- Department of Internal Medicine and Oncology (DIMO), University of Bari, P.za Giulio Cesare, 11--70124 Bari, Italy
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18
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Chen JC, Huang KC, Wingerd B, Wu WT, Lin WW. HMG-CoA reductase inhibitors induce COX-2 gene expression in murine macrophages: role of MAPK cascades and promoter elements for CREB and C/EBPβ. Exp Cell Res 2004; 301:305-19. [PMID: 15530865 DOI: 10.1016/j.yexcr.2004.05.039] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2003] [Revised: 03/30/2004] [Indexed: 12/24/2022]
Abstract
Except functioning as lipid-lowering agents, HMG-CoA inhibitors, statins, are good tools to clarify the signaling role of small G proteins. In this study, we found in murine RAW264.7 macrophages, statins within 1-30 microM stimulated COX-2 gene transcription and PGE(2) formation, displaying potencies as lovastatin > fluvastatin > atorvastatin >> pravastatin. Transfection experiments with COX-2 promoter construct showed the necessity of C/EBPbeta and CRE promoter sites, but not NF-kappaB promoter site. Effects of statins on the activation of COX-2 promoter, induction of COX-2 protein, and PGE(2) production were all prevented by mevalonate and prenylated metabolites, FPP and GGPP. Consistent with the effect of statins, manumycin A, farnesyltransferase inhibitor, and geranylgeranyltransferase inhibitor increased PGE(2) production and COX-2 induction. Likewise, toxin B, an inhibitor of Rho family members, caused a prominent COX-2 induction. Results also indicated that tyrosine kinase, ERK, and p38 MAPK play essential roles in statin action. Taken together, these results not only demonstrate a unique action of statins in the upregulation of COX-2 expression in macrophages, but also suggest a negative role controlled by small G proteins in COX-2 gene regulation. Removal of this negative control by impairing G protein prenylation with statins leads to MAPKs activation and promotes COX-2 gene expression through the activation at CRE and C/EBPbeta sites.
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Affiliation(s)
- Jui-Ching Chen
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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19
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Huynh T, Cordato D, Yang F, Choy T, Johnstone K, Bagnall F, Hitchens N, Dunn R. HMG CoA reductase-inhibitor-related myopathy and the influence of drug interactions. Intern Med J 2002; 32:486-90. [PMID: 12380704 DOI: 10.1046/j.1445-5994.2002.00264.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report four cases of rhabdomyolysis and severe, disabling myopathy associated with HMG CoA reductase-inhibitor therapy. Patient developed symptoms following the addition of roxithromycin to combination lipid-lowering therapy with simvastatin and gemfibrozil. Patients 2 and 3 became symptomatic after developing acute on chronic renal impairment while taking simvastatin. The muscle biopsy of patient 3 revealed a necrotizing myopathy and the presence of inclusion bodies. Patient 4 developed symptoms within 4 weeks of starting cerivastatin monotherapy. The four cases illustrate the importance of considering the potential for drug interactions and making appropriate dosage adjustments for renal insufficiency in patients receiving HMG CoA reductase therapy.
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Affiliation(s)
- T Huynh
- Department of Aged Care, Bankstown-Lidcombe Hospital, Bankstown, New South Wales, Australia
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20
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Moffatt J, Kennedy DO, Kojima A, Hasuma T, Yano Y, Otani S, Murakami A, Koshimizu K, Ohigashi H, Matsui-Yuasa I. Involvement of protein tyrosine phosphorylation and reduction of cellular sulfhydryl groups in cell death induced by 1' -acetoxychavicol acetate in Ehrlich ascites tumor cells. Chem Biol Interact 2002; 139:215-30. [PMID: 11823008 DOI: 10.1016/s0009-2797(01)00301-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Elucidation of the mechanisms underlying potential anticancer drugs continues and unraveling these mechanisms would not only provide a conceptual framework for drug design but also promote use of natural products for chemotherapy. To further evaluate the efficacy of the anticancer activity of 1'-acetoxychavicol acetate (ACA), this study investigates the underlying mechanisms by which ACA induces death of Ehrlich ascites tumor cells. ACA treatment induced loss of cell viability, and Western blotting analysis revealed that the compound stimulated tyrosine phosphorylation of several proteins with 27 and 70 kDa proteins being regulated in both dose- and time-dependent manner prior to loss of viability. Protein tyrosine kinase inhibitor herbimycin A moderately protected cells from ACA-induced toxicity. In addition, cellular glutathione and protein sulfydryl groups were also significantly reduced both dose- and time-dependently during evidence of cell death. Replenishing thiol levels by antioxidant, N-acetylcysteine (NAC), an excellent supplier of glutathione and precursor of glutathione, substantially recovered the viability loss, but the recovery being time-dependent, as late addition of NAC (at least 30 min after ACA addition to cultures) was, however, ineffective. Addition of NAC to ACA treated cultures also abolished tyrosine phosphorylation of the 27 kDa protein. These results, at least partly, identify cellular sulfhydryl groups and protein tyrosine phosphorylation as targets of ACA cytotoxicity in tumor cells.
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Affiliation(s)
- Jerry Moffatt
- Department of Food and Human Health Sciences, Graduate School of Human Life Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
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21
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Nakagawa H, Mutoh T, Kumano T, Kuriyama M. Tyrosine phosphorylation of the catalytic subunit p110 of phosphatidylinositol-3 kinase induced by HMG-CoA reductase inhibitor inhibits its kinase activity in L6 myoblasts. FEBS Lett 2001; 508:53-6. [PMID: 11707267 DOI: 10.1016/s0014-5793(01)03021-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Previous studies from this laboratory have shown that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (HCRI) causes apoptotic cell death of a muscle cell-derived cell line, L6 myoblasts, by involving the phosphatidylinositol-3 (PI-3) kinase pathway and tyrosine phosphorylation of several cellular proteins, although the relationship between PI-3 kinase pathway and tyrosine phosphorylation responses remained to be elucidated. Here, we show that HCRI induces tyrosine phosphorylation of catalytic subunit p110 of PI-3 kinase as early as 5 min after addition of HCRI into culture medium. We could not detect the tyrosine phosphorylation of the regulatory subunit p85 of PI-3 kinase under the present experimental conditions. Concomitantly, the kinase activity toward PI in p110 immunoprecipitates was decreased with a similar time course. Furthermore, both herbimycin A and genistein, potent inhibitors of tyrosine kinase activity, inhibited HCRI-induced inhibition of PI-3 kinase activity as well as HCRI-induced apoptotic cell death. Once the catalytic subunit p110 becomes tyrosine-phosphorylated, the regulatory subunit p85 appears to be dissociated from the catalytic subunit, because we observed a decreasing amount of p85 regulatory subunits in p110 immunoprecipitates in response to HCRI treatment. These results strongly suggest the novel function of tyrosine phosphorylation of catalytic subunit p110 of PI-3 kinase in the regulation of its kinase activity. The tyrosine phosphorylation of these catalytic subunits may play an important role in the intracellular signal transduction of apoptotic cell death. To our knowledge, this is the first report that tyrosine phosphorylation of p110 catalytic subunit acts as a negative regulator of its kinase activity.
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Affiliation(s)
- H Nakagawa
- The Second Department of Internal Medicine, Division of Neurology, Faculty of Medicine, Fukui Medical University, 23-Shimoaitsuki, Matsuoka-cho, Fukui 910-1193, Japan
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22
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Ye LY, Firby PS, Moore MJ. Determination of lovastatin in human plasma using reverse-phase high-performance liquid chromatography with UV detection. Ther Drug Monit 2000; 22:737-41. [PMID: 11128243 DOI: 10.1097/00007691-200012000-00014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The authors have developed a simple, rapid HPLC assay with ultraviolet (UV) detection for the analytical determination of lovastatin and its acid in human plasma for a concentration range of 100-5,000 ng/mL. Sample clean-up involved the use of C10 solid-phase extraction cartridges. Our limit of quantitation was 100 ng/mL. Standard curves were linear from 100 to 5,000 ng/mL, with a correlation coefficient (r2) of 0.999 +/- 0.0002. Stored samples were stable at -70 degrees C for up to 4 months prior to reversed-phase HPLC analysis. This assay was able to measure steady-state lovastatin concentration (Css) at the initial dose level in a phase I trial of lovastatin as a modulator of apoptosis.
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Affiliation(s)
- L Y Ye
- Department of Experimental Therapeutics, Faculty of Pharmacy, University of Toronto, Ontario, Canada
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23
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Kumano T, Mutoh T, Nakagawa H, Kuriyama M. HMG-CoA reductase inhibitor induces a transient activation of high affinity nerve growth factor receptor, trk, and morphological differentiation with fatal outcome in PC12 cells. Brain Res 2000; 859:169-72. [PMID: 10720627 DOI: 10.1016/s0006-8993(99)02469-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present study was aimed at investigating the possible toxicity of simvastatin on a neuronal cell line, PC12 cells. Simvastatin clearly induced a transient morphological differentiation as evidenced by the occurrence of neurite outgrowth with a transient activation of the high affinity nerve growth factor receptor, Trk, but died at 36 h after its addition. Tyrosine autophosphorylation of the Trk protein also disappeared at 36 h after addition. During the morphological differentiation, NGF mRNA expression was upregulated transiently and returned to the basal level at 36 h after addition of simvastatin. These results suggest that simvastatin is neurotoxic and PC12 cells elicited a protective response, involving a transient activation of a Trk-mediated intracellular signal transduction pathway by an autocrine secretion of NGF, although these responses did not persist against pro-apoptotic signals and resulted in an apoptosis of the PC12 cells.
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Affiliation(s)
- T Kumano
- Second Department of Internal Medicine, Division of Neurology, Faculty of Medicine, Fukui Medical University, 23-Shimoaizuki, Matsuoka-cho, Fukui, Japan
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Abstract
Statins have pleiotropic properties that complement their cholesterol-lowering effects. These properties may partly account for their established benefit in the prevention of coronary artery disease beyond the reduction of LDL-cholesterol levels. The most widely recognized properties are reviewed here. They include: (i) nitric oxide-mediated improvement of endothelial dysfunction and upregulation of endothelin-1 expression; (ii) antioxidant effects; (iii) anti-inflammatory properties; (iv) inhibition of cell proliferation with anticarcinogenic actions in animals; (v) stabilization of atherosclerotic plaques; (vi) anticoagulant effects; and (vii) inhibition of graft rejection after heart and kidney transplantation. As advances are made in our knowledge, new properties are steadily being uncovered. Pleiotropic effects are currently being given consideration when instituting combination therapy for patients at high cardiovascular risk. Some pleiotropic effects are negative, and may account for occasional untoward drug interactions. For many of these new properties, the clinical relevance has not been established. The challenge for the future will be to design and carry out appropriate clinical trials to establish their relative importance in the prevention of coronary artery disease.
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Affiliation(s)
- J Davignon
- Hyperlipidemia and Atherosclerosis Research Group, Clinical Research Institute of Montreal, Quebec, Canada.
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