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Chang TT, Wu TC, Huang PH, Lin CP, Chen JS, Lin LY, Lin SJ, Chen JW. Direct Renin Inhibition with Aliskiren Improves Ischemia-Induced Neovasculogenesis in Diabetic Animals via the SDF-1 Related Mechanism. PLoS One 2015; 10:e0136627. [PMID: 26305217 PMCID: PMC4549314 DOI: 10.1371/journal.pone.0136627] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 08/05/2015] [Indexed: 12/20/2022] Open
Abstract
Objective Aliskiren is a direct renin inhibitor which is suggested to modify proangiogenic cells in addition to lower blood pressure. Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs) and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals. Methods Streptozotocin-induced diabetic mice were administered with either aliskiren (5 or 25 mg/kg/day) using an osmotic pump or hydralazine (2 or 10 mg/kg/day) given in drinking water for two weeks prior to a hind-limb ischemia surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively. Results In streptozotocin-induced diabetic mice, aliskiren enhanced the recovery of limb perfusion and capillary density, increased the number of circulating Sca-1+/Flk-1+ EPC-like cells, and elevated the levels of the plasma vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1α in a dose-dependent manner, whereas there were no such effects in hydralazine-treated mice. Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren. Conclusions Independent of the reduction of blood pressure, aliskiren enhanced ischemia-induced neovasculogenesis in a dose-dependent manner via VEGF/SDF-1α related mechanisms in diabetic mice.
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Affiliation(s)
- Ting-Ting Chang
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, R.O.C
| | - Tao-Cheng Wu
- Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
- Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan, R.O.C
| | - Po-Hsun Huang
- Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
- Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan, R.O.C
| | - Chih-Pei Lin
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
| | - Jia-Shiong Chen
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan, R.O.C
| | - Liang-Yu Lin
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
| | - Shing-Jong Lin
- Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
- Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
| | - Jaw-Wen Chen
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
- Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C
- * E-mail:
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Toyama K, Koibuchi N, Hasegawa Y, Uekawa K, Yasuda O, Sueta D, Nakagawa T, Ma M, Kusaka H, Lin B, Ogawa H, Ichijo H, Ichijo H, Kim-Mitsuyama S. ASK1 is involved in cognitive impairment caused by long-term high-fat diet feeding in mice. Sci Rep 2015; 5:10844. [PMID: 26044555 PMCID: PMC5377457 DOI: 10.1038/srep10844] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/05/2015] [Indexed: 12/31/2022] Open
Abstract
Although high-fat diet intake is known to cause obesity and diabetes, the effect of high-fat diet itself on cognitive function remains to be clarified. We have previously shown that apoptosis signal-regulating kinase 1 (ASK1) is responsible for cognitive impairment caused by chronic cerebral hypoperfusion. The present work, by using ASK1 deficient mice, was undertaken to explore the influence of chronic high-fat diet intake on cognitive function and the role of ASK1. Cognitive function in wild-type mice fed high-fat diet from 2 to 24 months of age was significantly impaired compared to those fed control diet, which was associated with the significant white matter lesions, reduction of hippocampal capillary density, and decrement of hippocampal neuronal cell. However, ASK1 deficiency abolished the development of cognitive impairment and cerebral injury caused by high-fat diet. Our results provided the evidence that high-fat diet itself causes cognitive impairment and ASK1 participates in such cognitive impairment.
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Affiliation(s)
| | | | | | | | - Osamu Yasuda
- Department of Cardiovascular Clinical and Translational Research, Kumamoto University Hospital, Kumamoto
| | | | | | | | | | | | - Hisao Ogawa
- Department of Cardiovascular Medicine, Kumamoto University Graduate School of Medical Sciences, Kumamoto
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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Alleman RJ, Katunga LA, Nelson MAM, Brown DA, Anderson EJ. The "Goldilocks Zone" from a redox perspective-Adaptive vs. deleterious responses to oxidative stress in striated muscle. Front Physiol 2014; 5:358. [PMID: 25278906 PMCID: PMC4166897 DOI: 10.3389/fphys.2014.00358] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 09/02/2014] [Indexed: 01/17/2023] Open
Abstract
Consequences of oxidative stress may be beneficial or detrimental in physiological systems. An organ system's position on the “hormetic curve” is governed by the source and temporality of reactive oxygen species (ROS) production, proximity of ROS to moieties most susceptible to damage, and the capacity of the endogenous cellular ROS scavenging mechanisms. Most importantly, the resilience of the tissue (the capacity to recover from damage) is a decisive factor, and this is reflected in the disparate response to ROS in cardiac and skeletal muscle. In myocytes, a high oxidative capacity invariably results in a significant ROS burden which in homeostasis, is rapidly neutralized by the robust antioxidant network. The up-regulation of key pathways in the antioxidant network is a central component of the hormetic response to ROS. Despite such adaptations, persistent oxidative stress over an extended time-frame (e.g., months to years) inevitably leads to cumulative damages, maladaptation and ultimately the pathogenesis of chronic diseases. Indeed, persistent oxidative stress in heart and skeletal muscle has been repeatedly demonstrated to have causal roles in the etiology of heart disease and insulin resistance, respectively. Deciphering the mechanisms that underlie the divergence between adaptive and maladaptive responses to oxidative stress remains an active area of research for basic scientists and clinicians alike, as this would undoubtedly lead to novel therapeutic approaches. Here, we provide an overview of major types of ROS in striated muscle and the divergent adaptations that occur in response to them. Emphasis is placed on highlighting newly uncovered areas of research on this topic, with particular focus on the mitochondria, and the diverging roles that ROS play in muscle health (e.g., exercise or preconditioning) and disease (e.g., cardiomyopathy, ischemia, metabolic syndrome).
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Affiliation(s)
- Rick J Alleman
- Departments of Physiology, East Carolina University Greenville, NC, USA ; East Carolina Diabetes and Obesity Institute, East Carolina University Greenville, NC, USA
| | - Lalage A Katunga
- East Carolina Diabetes and Obesity Institute, East Carolina University Greenville, NC, USA ; Pharmacology and Toxicology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - Margaret A M Nelson
- East Carolina Diabetes and Obesity Institute, East Carolina University Greenville, NC, USA ; Pharmacology and Toxicology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - David A Brown
- Departments of Physiology, East Carolina University Greenville, NC, USA ; East Carolina Diabetes and Obesity Institute, East Carolina University Greenville, NC, USA
| | - Ethan J Anderson
- East Carolina Diabetes and Obesity Institute, East Carolina University Greenville, NC, USA ; Pharmacology and Toxicology, Brody School of Medicine, East Carolina University Greenville, NC, USA
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Starosyla SA, Volynets GP, Bdzhola VG, Golub AG, Protopopov MV, Yarmoluk SM. ASK1 pharmacophore model derived from diverse classes of inhibitors. Bioorg Med Chem Lett 2014; 24:4418-4423. [DOI: 10.1016/j.bmcl.2014.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 10/24/2022]
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The efficacy and tolerability of azilsartan in obese insulin-resistant mice with left ventricular pressure overload. J Cardiovasc Pharmacol 2014; 62:381-7. [PMID: 23921308 DOI: 10.1097/fjc.0b013e31829f0c1b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Angiotensin II receptor blockers (ARBs) are used widely for the treatment of heart failure. However, their use in obese and insulin-resistant patients remains controversial. To clarify their potential efficacy in these conditions, we administered azilsartan medoxomil (azilsartan), a prodrug of an angiotensin II receptor blocker to mice fed a high-fat diet (HFD) with left ventricular (LV) pressure overload (aortic banding). LV fibrosis (hydroxyproline), cardiac plasminogen activator inhibitor-1 (PAI-1; a marker of profibrosis), and creatine kinase (a marker of myocardial viability and energetics) were assessed. LV wall thickness and cardiac function were assessed echocardiographically. Mice given a HFD were obese and insulin resistant. Their LV hypertrophy was accompanied by greater LV PAI-1 and reduced LV creatine kinase compared with normal diet controls. Drug treatment reduced LV wall thickness, hypertrophy, and PAI-1 and increased cardiac output after aortic banding compared with results in HFD vehicle controls. Thus, azilsartan exerted favorable biological effects on the hearts of obese insulin-resistant mice subjected to LV pressure overload consistent with its potential utility in patients with analogous conditions.
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Rabhi N, Salas E, Froguel P, Annicotte JS. Role of the unfolded protein response in β cell compensation and failure during diabetes. J Diabetes Res 2014; 2014:795171. [PMID: 24812634 PMCID: PMC4000654 DOI: 10.1155/2014/795171] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β cell failure leads to diabetes development. During disease progression, β cells adapt their secretory capacity to compensate the elevated glycaemia and the peripheral insulin resistance. This compensatory mechanism involves a fine-tuned regulation to modulate the endoplasmic reticulum (ER) capacity and quality control to prevent unfolded proinsulin accumulation, a major protein synthetized within the β cell. These signalling pathways are collectively termed unfolded protein response (UPR). The UPR machinery is required to preserve ER homeostasis and β cell integrity. Moreover, UPR actors play a key role by regulating ER folding capacity, increasing the degradation of misfolded proteins, and limiting the mRNA translation rate. Recent genetic and biochemical studies on mouse models and human UPR sensor mutations demonstrate a clear requirement of the UPR machinery to prevent β cell failure and increase β cell mass and adaptation throughout the progression of diabetes. In this review we will highlight the specific role of UPR actors in β cell compensation and failure during diabetes.
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Affiliation(s)
- Nabil Rabhi
- European Genomic Institute for Diabetes (EGID), CNRS UMR 8199, Lille 2 University of Health and Law, 59000 Lille, France
| | - Elisabet Salas
- European Genomic Institute for Diabetes (EGID), CNRS UMR 8199, Lille 2 University of Health and Law, 59000 Lille, France
| | - Philippe Froguel
- European Genomic Institute for Diabetes (EGID), CNRS UMR 8199, Lille 2 University of Health and Law, 59000 Lille, France
- Departments of Genomics of Common Disease, Hammersmith Hospital, Imperial College London, London, UK
| | - Jean-Sébastien Annicotte
- European Genomic Institute for Diabetes (EGID), CNRS UMR 8199, Lille 2 University of Health and Law, 59000 Lille, France
- Laboratoire Bases Moléculaires et Modélisation du Diabète et de l'Obésité, Faculté de Médecine, Pôle Recherche, 59045 Lille, France
- *Jean-Sébastien Annicotte:
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Matthew Morris E, Fletcher JA, Thyfault JP, Rector RS. The role of angiotensin II in nonalcoholic steatohepatitis. Mol Cell Endocrinol 2013; 378:29-40. [PMID: 22579612 DOI: 10.1016/j.mce.2012.04.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 04/30/2012] [Indexed: 01/18/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is now considered the most prevalent chronic liver disease, affecting over 30% of the US adult population. NAFLD is strongly linked to insulin resistance and is considered the hepatic manifestation of the metabolic syndrome. Activation of the renin-angiotensin-aldosterone system (RAAS) is known to play a role in the hypertension observed in the metabolic syndrome and also is thought to play a central role in insulin resistance and NAFLD. Angiotensin II (AngII) is considered the primary effector of the physiological outcomes of RAAS signaling, both at the systemic and local tissue level. Herein, we review data describing the potential involvement of AngII-mediated signaling at multiple levels in the development and progression of NAFLD, including increased steatosis, inflammation, insulin resistance, and fibrosis. Additionally, we present recent work on the potential therapeutic benefits of RAAS and angiotensin II signaling inhibition in rodent models and patients with NAFLD.
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Affiliation(s)
- E Matthew Morris
- Department of Internal Medicine - Division of Gastroenterology and Hepatology, University of Missouri, MO, United States; Harry S Truman Memorial Veterans Medical Center, Columbia, MO 65201, United States.
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Shah RV, Abbasi SA, Neilan TG, Hulten E, Coelho-Filho O, Hoppin A, Levitsky L, de Ferranti S, Rhodes ET, Traum A, Goodman E, Feng H, Heydari B, Harris WS, Hoefner DM, McConnell JP, Seethamraju R, Rickers C, Kwong RY, Jerosch-Herold M. Myocardial tissue remodeling in adolescent obesity. J Am Heart Assoc 2013; 2:e000279. [PMID: 23963758 PMCID: PMC3828806 DOI: 10.1161/jaha.113.000279] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Childhood obesity is a significant risk factor for cardiovascular disease in adulthood. Although ventricular remodeling has been reported in obese youth, early tissue-level markers within the myocardium that precede organ-level alterations have not been described. METHODS AND RESULTS We studied 21 obese adolescents (mean age, 17.7±2.6 years; mean body mass index [BMI], 41.9±9.5 kg/m(2), including 11 patients with type 2 diabetes [T2D]) and 12 healthy volunteers (age, 15.1±4.5 years; BMI, 20.1±3.5 kg/m(2)) using biomarkers of cardiometabolic risk and cardiac magnetic resonance imaging (CMR) to phenotype cardiac structure, function, and interstitial matrix remodeling by standard techniques. Although left ventricular ejection fraction and left atrial volumes were similar in healthy volunteers and obese patients (and within normal body size-adjusted limits), interstitial matrix expansion by CMR extracellular volume fraction (ECV) was significantly different between healthy volunteers (median, 0.264; interquartile range [IQR], 0.253 to 0.271), obese adolescents without T2D (median, 0.328; IQR, 0.278 to 0.345), and obese adolescents with T2D (median, 0.376; IQR, 0.336 to 0.407; P=0.0001). ECV was associated with BMI for the entire population (r=0.58, P<0.001) and with high-sensitivity C-reactive protein (r=0.47, P<0.05), serum triglycerides (r=0.51, P<0.05), and hemoglobin A1c (r=0.76, P<0.0001) in the obese stratum. CONCLUSIONS Obese adolescents (particularly those with T2D) have subclinical alterations in myocardial tissue architecture associated with inflammation and insulin resistance. These alterations precede significant left ventricular hypertrophy or decreased cardiac function.
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Affiliation(s)
- Ravi V Shah
- Noninvasive Cardiovascular Imaging Section, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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Neuroprotective function of DJ-1 in Parkinson's disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:683920. [PMID: 23766857 PMCID: PMC3671546 DOI: 10.1155/2013/683920] [Citation(s) in RCA: 254] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 04/24/2013] [Accepted: 04/29/2013] [Indexed: 11/18/2022]
Abstract
Parkinson's disease (PD) is caused by dopaminergic neuronal death in the substantia nigra, resulting in a reduced level of dopamine in the striatum. Oxidative stress and mitochondrial dysfunction are thought to be major causes of neurodegeneration in PD. Although genetic and environmental factors are thought to affect the onset of PD, precise mechanisms at the molecular level have not been elucidated. The DJ-1 gene is a causative gene for familial PD (park7) and also an oncogene. DJ-1 has various functions, including transcriptional regulation, antioxidative stress reaction, and chaperone, protease, and mitochondrial regulation, and its activity is regulated by its oxidative status, especially that of cysteine 106 (C106) of DJ-1. Excess oxidation of DJ-1, which renders DJ-1 inactive, has been observed in patients with sporadic PD and Alzheimer's disease, suggesting that DJ-1 also participates in the onset and pathogenesis of sporadic PD as well as familial PD. DJ-1 is also a stress sensor and its expression is increased upon various stresses, including oxidative stress. In this review, we describe functions of DJ-1 against oxidative stress and possible roles of DJ-1 in the pathogenesis of PD.
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Noda K, Hosoya M, Nakajima S, Ohashi J, Fukumoto Y, Shimokawa H. Anti-atherogenic effects of the combination therapy with olmesartan and azelnidipine in diabetic apolipoprotein E-deficient mice. TOHOKU J EXP MED 2013; 228:305-15. [PMID: 23124103 DOI: 10.1620/tjem.228.305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Many studies have aimed to identify anti-atherogenic agents in cardiovascular medicine. We have recently demonstrated that the combination therapy with olmesartan (OLM), an angiotensin II receptor blocker, and azelnidipine (AZL), a dihydroprydine calcium-channel blocker, improves endothelial function in diabetic Apolipoprotein-deficient (ApoE(-/-)) mice. In the present study, we examined whether this combination therapy also inhibits atherosclerosis in mice. We used male control and streptozocin-induced diabetic ApoE(-/-) mice. Diabetic ApoE(-/-) mice were orally treated for 5 weeks with vehicle (Untreated), OLM (30 mg/kg/day), AZL (10 mg/kg/day), their combination (OLM+AZL), or hydralazine (HYD, 5 mg/kg/day) as an antihypertensive control. At 5 weeks, systolic blood pressure was significantly elevated in Untreated but was normalized in OLM+AZL and HYD. The atherosclerosis area in the thoracic aorta, perivascular fibrosis and medial thickness of the coronary arteries were increased in Untreated and were ameliorated in OLM+AZL but not in HYD. Staining with a fluorescent probe dihydroethidium showed that production of reactive oxygen species was increased in Untreated, and ameliorated in OLM+AZL. Consistent with these findings, macrophage infiltration in the kidney and the expression of receptor for advanced glycation end-products in the heart, kidney and liver were increased in Untreated and were all ameliorated in OLM+AZL, associated with up-regulation of endothelial NO syntheses (eNOS). In conclusion, the combination therapy with OLM and AZL exerts anti-atherogenic effect in diabetic ApoE(-/-) mice through suppression of oxidative stress and activation of eNOS, independent of its blood pressure-lowering effects. Clinically, this combination therapy may be useful for patients with hypertension, hyperlipidemia and diabetes.
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Affiliation(s)
- Kazuki Noda
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
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61
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The role of the unfolded protein response in diabetes mellitus. Semin Immunopathol 2013; 35:333-50. [PMID: 23529219 DOI: 10.1007/s00281-013-0369-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 03/13/2013] [Indexed: 12/13/2022]
Abstract
The endoplasmic reticulum (ER) plays a key role in the synthesis and modification of secretory and membrane proteins in all eukaryotic cells. Under normal conditions, these proteins are correctly folded and assembled in the ER. However, when cells are exposed to environmental factors such as overproduction of ER proteins, viral infections, or glucose deprivation, the secretory and membrane proteins can accumulate in unfolded or misfolded forms in the lumen of the ER, and consequently, cause stress in the ER. To maintain cellular homeostasis, cells induce several responses to ER stress. In mammalian cells, ER stress responses are induced by a diversity of signal pathways. There are three ER-located transmembrane proteins that play important roles in mammalian ER stress responses: activating transcription factor 6, inositol-requiring protein 1, and protein kinase RNA-like endoplasmic reticulum kinase. ER stress is linked to various diseases, including diabetes. This review highlights the particular importance of ER stress-responsive molecules in insulin biosynthesis, glyconeogenesis, insulin resistance, glucose intolerance, and pancreatic β-cell apoptosis. An understanding of the pathogenic mechanism of diabetes from the aspect of ER stress is crucial in formulating therapeutic strategies.
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Volynets GP, Bdzhola VG, Golub AG, Synyugin AR, Chekanov MA, Kukharenko OP, Yarmoluk SM. Rational design of apoptosis signal-regulating kinase 1 inhibitors: Discovering novel structural scaffold. Eur J Med Chem 2013; 61:104-15. [DOI: 10.1016/j.ejmech.2012.09.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 08/30/2012] [Accepted: 09/13/2012] [Indexed: 11/28/2022]
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Ogawa H, Kim-Mitsuyama S, Matsui K, Jinnouchi T, Jinnouchi H, Arakawa K. Angiotensin II receptor blocker-based therapy in Japanese elderly, high-risk, hypertensive patients. Am J Med 2012; 125:981-90. [PMID: 22503610 DOI: 10.1016/j.amjmed.2011.12.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/20/2011] [Accepted: 12/20/2011] [Indexed: 11/25/2022]
Abstract
BACKGROUND It is unknown whether high-dose angiotensin II receptor blocker therapy or angiotensin II receptor blocker + calcium channel blocker combination therapy is better in elderly hypertensive patients with high cardiovascular risk. The objective of the study was to compare the efficacy of these treatments in elderly, high-risk Japanese hypertensive patients. METHODS The OlmeSartan and Calcium Antagonists Randomized (OSCAR) study was a multicenter, prospective, randomized, open-label, blinded-end point study of 1164 hypertensive patients aged 65 to 84 years with type 2 diabetes or cardiovascular disease. Patients with uncontrolled hypertension during treatment with olmesartan 20 mg/d were randomly assigned to receive 40 mg/d olmesartan (high-dose angiotensin II receptor blocker) or a calcium channel blocker + 20 mg/d olmesartan (angiotensin II receptor blocker + calcium channel blocker). The primary end point was a composite of cardiovascular events and noncardiovascular death. RESULTS During a 3-year follow-up, blood pressure was significantly lower in the angiotensin II receptor blocker + calcium channel blocker group than in the high-dose angiotensin II receptor blocker group. Mean blood pressure at 36 months was 135.0/74.3 mm Hg in the high-dose angiotensin II receptor blocker group and 132.6/72.6 mm Hg in the angiotensin II receptor blocker + calcium channel blocker group. More primary end points occurred in the high-dose angiotensin II receptor blocker group than in the angiotensin II receptor blocker + calcium channel blocker group (58 vs 48 events, hazard ratio [HR], 1.31, 95% confidence interval, 0.89-1.92; P=.17). In patients with cardiovascular disease at baseline, more primary events occurred in the high-dose angiotensin II receptor blocker group (HR, 1.63, P=.03); in contrast, fewer events were observed in the subgroup without cardiovascular disease (HR, 0.52, P=.14). This treatment-by-subgroup interaction was significant (P=.02). CONCLUSION The angiotensin II receptor blocker and calcium channel blocker combination lowered blood pressure more than the high-dose angiotensin II receptor blocker and reduced the incidence of primary end points more than the high-dose angiotensin II receptor blocker in patients with cardiovascular disease. The addition of a second antihypertensive agent is more effective at lowering blood pressure than simply doubling the dose of an existing agent.
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Affiliation(s)
- Hisao Ogawa
- Department of Cardiovascular Medicine, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
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Mitsuyama S. [Role of the renin-angiotensin system in the brain and cardiorenal system]. Nihon Yakurigaku Zasshi 2012; 140:121-6. [PMID: 22975826 DOI: 10.1254/fpj.140.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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65
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Novel mechanism of salt-induced glomerular injury: critical role of eNOS and angiotensin II. J Hypertens 2012; 29:1528-35. [PMID: 21720272 DOI: 10.1097/hjh.0b013e328348ca95] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES The present study was undertaken to examine the role of endothelial nitric oxide synthase (eNOS) in salt-sensitive renal injury. METHODS The effects of high-salt diet on renal injury were compared between wild-type and eNOS-/- mice. To examine the role of glomerular angiotensin II and oxidative stress, high-salt fed eNOS-/- mice were given irbesartan, an angiotensin receptor blocker, or tempol, an antioxidant. RESULTS Four weeks of high-salt diet in wild-type mice, which rapidly caused glomerular eNOS activation and subsequent increase in nitric oxide, did not at all induce renal injury, indicating that wild-type mice are salt-resistant. On the contrary, high-salt diet in eNOS-/- mice, which little increased nitric oxide, rapidly increased urinary albumin excretion, followed by glomerular macrophage infiltration and glomerular sclerosis. Thus, eNOS deficiency caused salt-sensitive glomerular injury. Salt-induced glomerular injury in eNOS-/- mice was preceded by rapid enhancement of glomerular superoxide followed by enhancement of glomerular endothelial angiotensinogen and angiotensin II. Irbesartan and tempol, independently of blood pressure, markedly prevented salt-induced glomerular injury in eNOS-/- mice, and these protective effects were attributed to the attenuation of glomerular oxidative stress and glomerular angiotensinogen-derived angiotensin II. CONCLUSION We propose that eNOS dysfunction plays a causative role in salt-induced glomerular injury, through augmentation of glomerular oxidative stress-induced angiotensinogen.
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Sharma M, Urano F, Jaeschke A. Cdc42 and Rac1 are major contributors to the saturated fatty acid-stimulated JNK pathway in hepatocytes. J Hepatol 2012; 56:192-8. [PMID: 21703174 PMCID: PMC3183327 DOI: 10.1016/j.jhep.2011.03.019] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 03/14/2011] [Accepted: 03/16/2011] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Saturated free fatty acid (SFA)-stimulated c-Jun NH(2)-terminal kinase (JNK) activation is associated with the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the mechanisms responsible for the effects of SFA are incompletely understood. The goal of this study was to determine the molecular mechanisms by which SFA induce JNK activation in hepatocytes. METHODS We used siRNA-mediated knockdown in Hepa1c1c7 and AML12 cell lines, as well as primary mouse hepatocytes for these studies. RESULTS The current model for JNK activation by SFA involves endoplasmic reticulum (ER) stress, which induces JNK activation through an inositol requiring enzyme 1 (IRE1α) Apoptosis Regulating Kinase 1 (ASK1)-dependent mechanism. Here, we find that SFA-induced JNK activation is not inhibited in the absence of IRE1α and ASK1. Instead we show that activation of the small GTP-binding proteins Cdc42 and Rac1 is required for SFA-stimulated MLK3-dependent activation of JNK in hepatocytes. In addition, we demonstrate that SFA-induced cell death in hepatocytes is independent of IRE1α, but dependent on Cdc42, Rac1, and MLK3. CONCLUSIONS Our results demonstrate that Cdc42 and Rac1, rather than ER stress, are important components of a SFA-stimulated signaling pathway that regulates MLK3-dependent activation of JNK in hepatocytes.
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Affiliation(s)
| | - Fumihiko Urano
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts USA
| | - Anja Jaeschke
- Correspondence to: Anja Jaeschke; Department of Pathology; Metabolic Diseases Institute; University of Cincinnati; 2120 E. Galbraith Rd, Cincinnati, Ohio 45237 USA; Tel.: (513) 558-3898; Fax: (513) 558-1312;
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HAYAKAWA R, HAYAKAWA T, TAKEDA K, ICHIJO H. Therapeutic targets in the ASK1-dependent stress signaling pathways. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2012; 88:434-53. [PMID: 23060232 PMCID: PMC3491083 DOI: 10.2183/pjab.88.434] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Accepted: 08/17/2012] [Indexed: 05/25/2023]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family that activates downstream MAP kinases (MAPKs), c-Jun N-terminal kinases (JNKs) and p38 MAPKs, in response to various stresses, such as reactive oxygen species (ROS), endoplasmic reticulum (ER) stress, lipopolysaccharide, and calcium overload. Activation of the JNK and p38 pathways induces stress responses such as cell death, differentiation, and the production of inflammatory cytokines. A series of studies using ASK1-deficient mice have indicated that ASK1 plays important roles in many stress-related diseases, including cardiovascular and neurodegenerative diseases, suggesting that small compounds that inhibit ASK1 activity could possibly be used for the amelioration of the development and/or progression of these diseases. In this review, we provide an overview of the pathophysiological roles of ASK1-dependent signaling pathways and discuss the mechanistic basis for how these could serve as potential therapeutic targets.
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Affiliation(s)
- Ryoichi HAYAKAWA
- Laboratory of Cell Signaling, Graduate School of
Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Teruyuki HAYAKAWA
- Laboratory of Cell Signaling, Graduate School of
Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kohsuke TAKEDA
- Laboratory of Cell Signaling, Graduate School of
Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Division of Cell Regulation, Graduate School of Biomedical
Sciences, Nagasaki University, Nagasaki, Japan
| | - Hidenori ICHIJO
- Laboratory of Cell Signaling, Graduate School of
Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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Ishizaka N, Hongo M, Sakamoto A, Saito K, Furuta K, Koike K. Liver lipid content is reduced in rat given 7-day administration of angiotensin II. J Renin Angiotensin Aldosterone Syst 2011; 12:462-8. [PMID: 21810895 DOI: 10.1177/1470320311415887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Activation of the renin-angiotensin system may be involved in the development of hepatic steatosis, a condition that is associated with insulin resistance. We showed that in rats, angiotensin II induced accumulation of triglycerides in the renal tubular and cardiac cells, although it significantly reduced the weight of the rats. Here we investigated the liver lipid content of rats given long-term angiotensin II administration. Angiotensin II (0.7 mg/kg/day) was infused into the rats for 7 days via an osmotic minipump. Some rats also received hydralazine or losartan concomitantly. It was shown that angiotensin II reduced oil red O-stainable lipid droplets (6% of the control value) and liver triglyceride content (angiotensin II: 4.6 ± 0.8 µg/mg, control: 11.7 ± 1.1 µg/mg). Both of these phenomena were blocked by losartan, but not by hydralazine. Angiotensin II infusion reduced the expression and activity of AMP-activated protein kinase. In addition, angiotensin II decreased the mRNA expression of peroxisome proliferator-activated receptor-α and genes related to β-oxidation, although mRNA expression of genes related to lipogenesis were not affected. Angiotensin II reduced triglyceride content in the liver, unlike in the kidney or heart, via an AT1 receptor-dependent mechanism.
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Affiliation(s)
- Nobukazu Ishizaka
- Department of Cardiovascular Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
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Apoptosis signal-regulating kinase 1 deficiency eliminates cardiovascular injuries induced by high-salt diet. J Hypertens 2011; 29:76-84. [PMID: 20935579 DOI: 10.1097/hjh.0b013e32833fc8b0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES High-salt diet is closely associated with the increase in cardiovascular events. However, the mechanism of high-salt-induced cardiovascular injury is unknown. The present study was undertaken to test our hypothesis that apoptosis signal-regulating kinase (ASK) 1 may be involved in salt-induced cardiovascular injury. METHODS Wild-type and ASK1-/- mice were fed a low-salt or a high-salt diet for 10 weeks and the effects of high-salt diet on food intake, urinary volume and electrolyte excretion, and cardiovascular injury were compared between both groups of mice. RESULTS High-salt diet in wild-type and ASK1-/- mice similarly increased food intake, water intake, urine volume, and urinary sodium excretion, and comparably decreased plasma renin activity and aldosterone. Thus, ASK1 appears to play a minor role in the increase in natriuresis and the decrease in plasma renin, and aldosterone caused by high-salt diet. High-salt diet enhanced the phosphorylation of cardiovascular ASK1 in wild-type mice. High-salt diet in wild-type mice enhanced cardiac transforming growth factor-β1, interstitial fibrosis, coronary perivascular fibrosis, and inflammatory cell infiltration, and these changes were associated with the increase in cardiac superoxide and Nox2. ASK1 deficiency abolished the above-mentioned high-salt-induced cardiac injury. High-salt diet also caused the impairment of vascular endothelium-dependent relaxation by acetylcholine and increased vascular superoxide, and Nox2 in wild-type mice, whereas it did not cause vascular injury in ASK1-/- mice. CONCLUSION ASK1 is implicated in cardiac inflammation and fibrosis, and vascular endothelial dysfunction caused by high-salt diet, through the enhancement of oxidative stress.
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Volynets GP, Chekanov MO, Synyugin AR, Golub AG, Kukharenko OP, Bdzhola VG, Yarmoluk SM. Identification of 3H-naphtho[1,2,3-de]quinoline-2,7-diones as inhibitors of apoptosis signal-regulating kinase 1 (ASK1). J Med Chem 2011; 54:2680-6. [PMID: 21449566 DOI: 10.1021/jm200117h] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) has recently emerged as an attractive therapeutic target for the treatment of cardiac and neurodegenerative disorders. The selective inhibitors of ASK1 may become important compounds for the development of clinical agents. We have identified the ASK1 inhibitor among 3H-naphtho[1,2,3-de]quinoline-2,7-diones using receptor-based virtual screening. In vitro kinase assay revealed that ethyl 2,7-dioxo-2,7-dihydro-3H-naphtho[1,2,3-de]quinoline-1-carboxylate (NQDI-1) inhibited ASK1 with a K(i) of 500 nM. The competitive character of inhibition is demonstrated in Lineweaver-Burk plots. In our preliminary selectivity study this compound exhibited strong specific inhibitory activity toward ASK1.
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Affiliation(s)
- Galyna P Volynets
- Institute of Molecular Biology and Genetics, NAS of Ukraine, Kyiv, Ukraine
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Sturzeneker MCS, Ioshii SO, Villela Baroncini LA, Précoma DB. Olmesartan severely weakened the development of NASH in an animal model of hypercholesterolemia. Atherosclerosis 2011; 216:97-102. [PMID: 21338989 DOI: 10.1016/j.atherosclerosis.2011.01.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Revised: 01/14/2011] [Accepted: 01/28/2011] [Indexed: 01/07/2023]
Abstract
BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is characterized by a broad spectrum of liver damage. In a rat model of non-alcoholic steatohepatitis (NASH), olmesartan attenuated steatosis and fibrosis. OBJECTIVE To assess the potential preventive action of olmesartan, an angiotensin II type 1 receptor blocker, on NAFLD in hypercholesterolemic rabbits. METHODS Thirty-four white adult male rabbits were selected. The animals were divided into three groups: group I (GI), control group, 13 rabbits; group II (GII), olmesartan group, 12 rabbits; and group III (GIII), normal group, 9 rabbits. The animals from GI and GII were fed with a specific diet plus 1% cholesterol. Animals from GIII were fed only with a specific diet. The GII animals were treated with olmesartan. RESULTS Steatosis was present in all animals from GI and GII; no steatosis was observed in animals from GIII. When GI and GII where compared, the steatosis had higher scores in GI (p < 0.013). Perisinusoidal and periportal fibrosis occurred in 46.2% of the animals from GI. There was no fibrosis in GII or GIII. Lobular inflammation occurred in 84.6% of the animals from GI. Animals from GII and GIII had no inflammation. The NAFLD activity score was higher in animals from GI when compared to animals from GII and GIII (p < 0.001 for both groups); the NAFLD score was significantly higher in animals from GII when compared to animals from GIII (p < 0.001). CONCLUSIONS In hypercholesterolemic rabbits, olmesartan significantly attenuated hepatic steatosis and prevented the development of lobular inflammation and liver fibrosis. Based on the NAFLD activity score, olmesartan significantly weakened the development of NASH in rabbits fed a high cholesterol diet.
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Affiliation(s)
- Mário Cláudio Soares Sturzeneker
- Center of Health and Biological Sciences, Pontificia Universidade Católica do Paraná, Rua Imaculada Conceição, Avenida Iguacu 1325, ap 101B, 1155 Prado Velho, CEP 80215-901 Curitiba, Paraná, Brazil
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Aliskiren enhances protective effects of valsartan against type 2 diabetic nephropathy in mice. J Hypertens 2010; 28:1554-65. [PMID: 20375908 DOI: 10.1097/hjh.0b013e328338bb11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Addition of aliskiren, a direct renin inhibitor, to losartan provides additive reduction of urinary albumin excretion in type 2 diabetic patients. However, the detailed effect of aliskiren on type 2 diabetic nephropathy is still unknown. This study was undertaken to examine the efficacy of aliskiren and the combination of aliskiren with valsartan on type 2 diabetic nephropathy. METHODS db/db mice were treated with aliskiren (3 mg/kg per day), valsartan (5 or 10 mg/kg per day), combined aliskiren (3 mg/kg per day) and valsartan (5 mg/kg per day), and hydralazine (80 mg/kg per day), for 6 weeks, and the protective effects against diabetic nephropathy were compared among each group. RESULTS Aliskiren significantly attenuated albuminuria and glomerular mesangial matrix expansion in db/db mice, which was associated with the improvement of the increased glomerular transforming growth factor-beta and type IV collagen expressions, the increased macrophage infiltration, and the decreased glomerular nephrin expression of db/db mice. These protective effects of aliskiren in db/db mice were attributed to the attenuation of p22(phox)-related nicotinamide adenine dinucleotide phosphate oxidase-induced superoxide. Addition of aliskiren to valsartan treatment provided more beneficial effects on all the above-mentioned parameters than valsartan monotherapy. CONCLUSION Aliskiren protected against type 2 diabetic nephropathy, through pleiotropic effects, and significantly enhanced the protective effects of valsartan against diabetic nephropathy in db/db mice.
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Yamamoto E, Nakamura T, Kataoka K, Tokutomi Y, Dong YF, Fukuda M, Nako H, Yasuda O, Ogawa H, Kim-Mitsuyama S. Nifedipine prevents vascular endothelial dysfunction in a mouse model of obesity and type 2 diabetes, by improving eNOS dysfunction and dephosphorylation. Biochem Biophys Res Commun 2010; 403:258-63. [DOI: 10.1016/j.bbrc.2010.11.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 11/02/2010] [Indexed: 11/29/2022]
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Polyzos SA, Kountouras J, Zavos C, Tsiaousi E. The role of adiponectin in the pathogenesis and treatment of non-alcoholic fatty liver disease. Diabetes Obes Metab 2010; 12:365-83. [PMID: 20415685 DOI: 10.1111/j.1463-1326.2009.01176.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD. Adiponectin is the most abundant and adipose-specific adipokine. In the liver, adiponectin acts through the activation of 5-AMP-activated protein kinase and peroxisome proliferator-activated receptor-alpha pathways and inhibition of toll-like receptor-4 mediated signalling. There is an evidence that adiponectin decreases hepatic and systematic IR and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and severity of NAFLD, but it remains to be addressed to what extent this is a direct effect or related to the presence of more severe IR. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. Weight loss, through diet, lifestyle changes and/or medications including orlistat, sibutramine, rimonabant or bariatric surgery, increase adiponectin and may improve liver histology. Insulin sensitizers, including pioglitazone and rosiglitazone, and lipid-lowering agents, including statins and fibrates, also upregulate adiponectin and ameliorate liver histology. The wider use of new treatment approaches appears to signal the dawn of a new era in the management of NAFLD. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are systematically analysed.
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Affiliation(s)
- Stergios A Polyzos
- Second Medical Clinic, Medical School, Aristotle University of Thessaloniki, Ippokration Hospital, Thessaloniki, Greece.
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Potentiation by candesartan of protective effects of pioglitazone against type 2 diabetic cardiovascular and renal complications in obese mice. J Hypertens 2010; 28:340-52. [PMID: 19864959 DOI: 10.1097/hjh.0b013e32833366cd] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES The efficacy of renin-angiotensin system (RAS) blockers on type 2 diabetes and its complications remains to be defined. This study was undertaken to test the hypothesis that candesartan may enhance the protective effects of pioglitazone against type 2 diabetes. METHODS We compared the effects of pioglitazone, candesartan, and their combination on cardiorenal and vascular injury, diabetes, and tissue oxidative stress in obese and type 2 diabetic db/db mice, and also examined the effects of tempol, a superoxide dismutase (SOD) mimetic, on db/db mice to define the role of oxidative stress. RESULTS The addition of candesartan to pioglitazone significantly potentiated the suppressive effects of pioglitazone on cardiac macrophage infiltration and interstitial fibrosis, and glomerular macrophage infiltration and sclerosis in db/db mice. These benefits of the combination of pioglitazone and candesartan in db/db mice were attributed to additive attenuation of cardiorenal oxidative stress, through the attenuation of NADPH oxidase or the restoration of Cu/Zn-SOD and EC-SOD. The combination of these drugs reversed vascular endothelial dysfunction in db/db mice more than either monotherapy, by causing more phosphorylation of eNOS. Candesartan slightly augmented the improvement of glucose tolerance by pioglitazone in db/db mice, and this additive effect was mediated by more attenuation of oxidative stress. CONCLUSIONS Our work demonstrated that candesartan significantly potentiated the protective effects of pioglitazone against cardiorenal and vascular injury, and diabetes in obese type 2 diabetic mice. Thus, the combination of pioglitazone with candesartan is potentially a promising therapeutic strategy for type 2 diabetes.
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Hosoya M, Ohashi J, Sawada A, Takaki A, Shimokawa H. Combination therapy with olmesartan and azelnidipine improves EDHF-mediated responses in diabetic apolipoprotein E-deficient mice. Circ J 2010; 74:798-806. [PMID: 20154404 DOI: 10.1253/circj.cj-09-0862] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The endothelium modulates vascular tone by synthesizing and releasing several vasodilating factors, including vasodilator prostaglandins, nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). In the present study, we examined whether an angiotensin-receptor blocker, a calcium-channel blocker or their combination improved EDHF-mediated responses in diabetic apolipoprotein E-deficient (ApoE(-/-)) mice. METHODS AND RESULTS We used male C57BL/6N (control) and streptozocin-induced diabetic ApoE(-/-) mice. The diabetic ApoE(-/-) mice were administered oral vehicle (untreated), olmesartan (OLM, 30 mgxkg(-1)xday(-1)), azelnidipine (AZL, 10 mgxkg(-1)xday(-1)), their combination (OLM + AZL), or hydralazine (HYD 5 mgxkg(-1)xday(-1)) for 5 weeks. In the untreated group, systolic blood pressure was significantly higher and both EDHF-mediated relaxation and endothelium-dependent hyperpolarization were markedly reduced as compared with the control group. Although EDHF-mediated relaxation was not significantly improved in the HYD, OLM and AZL groups, it was significantly improved in the OLM + AZL group, as was also the case with phosphorylation of Akt and endothelial NO synthase (eNOS). In contrast, the endothelium-independent relaxation response to sodium nitroprusside or NS-1619 (a direct opener of K(Ca) channels) was unaltered in any group. CONCLUSIONS OLM + AZL may improve the severely impaired EDHF-mediated responses in diabetic ApoE(-/-) mice, in which activation of the endothelial Akt - eNOS pathway may be involved.
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Affiliation(s)
- Maki Hosoya
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
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Dong YF, Liu L, Kataoka K, Nakamura T, Fukuda M, Tokutomi Y, Nako H, Ogawa H, Kim-Mitsuyama S. Aliskiren prevents cardiovascular complications and pancreatic injury in a mouse model of obesity and type 2 diabetes. Diabetologia 2010; 53:180-91. [PMID: 19894030 DOI: 10.1007/s00125-009-1575-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 09/16/2009] [Indexed: 01/01/2023]
Abstract
AIMS/HYPOTHESIS The effect of renin inhibition on type 2 diabetes is still unclear. The present study was undertaken to examine the efficacy of aliskiren, a direct renin inhibitor, on cardiovascular injuries, glucose intolerance and pancreatic injury in a mouse model of type 2 diabetes. METHODS Groups of db/db mice, with obesity and type 2 diabetes, were treated with aliskiren (3, 6, 12 and 25 mg kg(-1) day(-1)) or hydralazine (80 mg kg(-1) day(-1)) for 6 weeks, and the protective effects were extensively compared among groups. RESULTS All sub-pressor and hypotensive doses of aliskiren significantly attenuated cardiac fibrosis, macrophage infiltration and coronary remodelling, and improved vascular endothelial function in db/db mice. These protective effects of aliskiren were attributed to the attenuation of cardiac p22(phox)-related NADPH oxidase-induced superoxide and the restoration of vascular endothelial nitric oxide synthase (eNOS) production. Aliskiren at the highest dose (25 mg kg(-1) day(-1)), but not at lower doses, partially reduced glucose intolerance in db/db mice. Furthermore, the highest dose of aliskiren significantly attenuated the decreases in pancreatic islet insulin content and beta cell mass, and prevented pancreatic islet fibrosis in db/db mice, being associated with the reduction of 8-hydroxy-2'-deoxyguanosine-positive cells and Nox2 (also known as Cybb) expression in pancreatic islets by aliskiren. CONCLUSIONS/INTERPRETATION Our work provides the first evidence that direct renin inhibition with aliskiren protects against cardiovascular complications and pancreatic injury, through the attenuation of oxidative stress. Thus, we propose that aliskiren may be a promising therapeutic agent for type 2 diabetes.
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Affiliation(s)
- Y F Dong
- Department of Pharmacology and Molecular Therapeutics, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
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Combination therapy of angiotensin receptor blocker with statin or thiazolidinediones as promising therapeutic strategy for metabolic syndrome and atherosclerosis. Hypertens Res 2009; 32:639-40. [DOI: 10.1038/hr.2009.90] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Yamamoto E, Kataoka K, Dong YF, Nakamura T, Fukuda M, Tokutomi Y, Matsuba S, Nako H, Nakagata N, Kaneko T, Ogawa H, Kim-Mitsuyama S. Aliskiren enhances the protective effects of valsartan against cardiovascular and renal injury in endothelial nitric oxide synthase-deficient mice. Hypertension 2009; 54:633-8. [PMID: 19597038 DOI: 10.1161/hypertensionaha.109.133884] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The protective effect of aliskiren, a direct renin inhibitor, against hypertensive cardiovascular and renal injury remains to be defined. This study was undertaken to examine the protective effects of the combination of aliskiren and valsartan, an angiotensin receptor blocker, against cardiovascular and renal injury. Endothelial NO synthase-deficient mice, subjected to cuff injury of femoral artery, were divided into 5 groups and were treated with the following: (1) vehicle; (2) aliskiren (25 mg/kg per day); (3) valsartan (8 mg/kg per day); (4) combined aliskiren (12.5 mg/kg per day) and valsartan (4 mg/kg per day); and (5) hydralazine (10 mg/kg per day) for 4 weeks. Aliskiren and valsartan alone markedly and similarly suppressed cardiac hypertrophy, inflammation and fibrosis, and coronary remodeling; prevented cuff injury-induced arterial intimal thickening; and reduced urinary albumin excretion, glomerular inflammation, and glomerulosclerosis in endothelial NO synthase-deficient mice. These beneficial effects of aliskiren and valsartan were associated with the significant attenuation of oxidative stress in these tissues. Hence, aliskiren and valsartan markedly exert the protective effects against cardiovascular and renal injury through the reduction of oxidative stress. Furthermore, compared with monotherapy with aliskiren or valsartan, the combination of a half dose of these drugs more greatly improved the above-mentioned cardiovascular and renal injuries of endothelial NO synthase-deficient mice, which were associated with greater attenuation of tissue oxidative stress by the combination therapy. Thus, the combination of aliskiren and valsartan exerts the synergistic organ-protective effects through synergistic attenuation of oxidative stress. The combination of aliskiren and valsartan seems to be a promising therapeutic strategy for hypertensive organ injury caused by endothelial NO synthase dysfunction.
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Affiliation(s)
- Eiichiro Yamamoto
- Department of Pharmacology and Molecular Therapeutics, Kumamoto University Graduate School of Medical Sciences, 1-1-1 Honjyo, Kumamoto, Japan
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Blüher M, Bashan N, Shai I, Harman-Boehm I, Tarnovscki T, Avinaoch E, Stumvoll M, Dietrich A, Klöting N, Rudich A. Activated Ask1-MKK4-p38MAPK/JNK stress signaling pathway in human omental fat tissue may link macrophage infiltration to whole-body Insulin sensitivity. J Clin Endocrinol Metab 2009; 94:2507-15. [PMID: 19351724 DOI: 10.1210/jc.2009-0002] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Adipose tissue in obesity is thought to be exposed to various stresses, predominantly in intraabdominal depots. We recently reported that p38MAPK and Jun N-terminal kinase (JNK), but not ERK and inhibitory-kappaB kinase beta, are more highly expressed and activated in human omental (OM) adipose tissue in obesity. OBJECTIVE The aim was to investigate upstream components of the pathways that culminate in activation of p38MAPK and JNK. SETTING AND PATIENTS Phosphorylation and expression of kinases were studied in paired samples of OM and sc adipose tissue from lean and obese subjects of two different cohorts (n = 36 and n = 196) by Western and real-time PCR analyses. The association with fat distribution, macrophage infiltration, insulin sensitivity, and glucose metabolism was assessed by correlation analyses. RESULTS The amount of phosphorylated forms of the kinases provided evidence for an activated stress-sensing pathway consisting of the MAP3K Ask1 (but not MLK3 or Tak1), and the MAP2Ks MKK4, 3/6, (but not MKK7), specifically in OM. OM Ask1-mRNA was more highly expressed in predominantly intraabdominally obese persons and most strongly correlated with estimated visceral fat. Diabetes was associated with higher OM Ask1-mRNA only in the lean group. In OM, macrophage infiltration strongly correlated with Ask1-mRNA, but the obesity-associated increase in Ask1-mRNA could largely be attributed to the adipocyte cell fraction. Finally, multivariate regression analyses revealed OM-Ask1 as an independent predictor of whole-body glucose uptake in euglycemic-hyperinsulinemic clamps. CONCLUSIONS An Ask1-MKK4-p38MAPK/JNK pathway reflects adipocyte stress associated with adipose tissue inflammation, linking visceral adiposity to whole-body insulin resistance in obesity.
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Affiliation(s)
- Matthias Blüher
- Department of Medicine, University of Leipzig, 04107 Leipzig, Germany
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Sonoyama T, Tamura N, Miyashita K, Park K, Oyamada N, Taura D, Inuzuka M, Fukunaga Y, Sone M, Nakao K. Inhibition of hepatic damage and liver fibrosis by brain natriuretic peptide. FEBS Lett 2009; 583:2067-70. [DOI: 10.1016/j.febslet.2009.05.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 05/11/2009] [Accepted: 05/14/2009] [Indexed: 11/26/2022]
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Ogawa H, Kim-Mitsuyama S, Jinnouchi T, Matsui K, Arakawa K. Rationale, design and patient baseline characteristics of OlmeSartan and calcium antagonists randomized (OSCAR) study: a study comparing the incidence of cardiovascular events between high-dose angiotensin II receptor blocker (ARB) monotherapy and combination therapy of ARB with calcium channel blocker in Japanese elderly high-risk hypertensive patients (ClinicalTrials. gov no. NCT00134160). Hypertens Res 2009; 32:575-80. [PMID: 19444280 DOI: 10.1038/hr.2009.60] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Higher doses of angiotensin II receptor blockers (ARBs) are expected to exert more protective effects against cardiovascular diseases. However, the significance of treatment of hypertension with high-dose ARB remains to be defined. The OlmeSartan and Calcium Antagonists Randomized (OSCAR) Study was designed to determine whether high-dose ARB monotherapy is superior to the combination therapy of ARB plus calcium channel blocker (CCB) in the prevention of cardiovascular morbidity/mortality in Japanese elderly high-risk hypertensive patients. The OSCAR study is a multicenter, active-controlled, two-arm parallel group comparison, using the prospective randomized open-blinded end-point method. In the 'Step 1' period, elderly hypertensive patients with diabetes or cardiovascular disease received monotherapy with ARB olmesartan medoxomil at a dose of 20 mg day(-1). If the target blood pressure control (less than 140/90 mm Hg) was not achieved by ARB monotherapy, the patients were randomized to receive either (1) the increased dose of olmesartan at 40 mg day(-1) (high-dose ARB monotherapy) or (2) the addition of a CCB (amlodipine or azelnidipine) to 20 mg day(-1) olmesartan (ARB plus CCB combination) in the 'Step 2' period. The follow-up duration will be 3 years. The primary end points will be the composite of fatal and non-fatal cardiovascular events, and death from any cause. Recruitment for the OSCAR study (around 1200 patients) was completed by the end of May 2007. The OSCAR study is the first large clinical trial comparing the efficacy of high-dose ARB monotherapy with that of an ARB plus CCB combination therapy in elderly high-risk hypertensive patients.
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Affiliation(s)
- Hisao Ogawa
- Department of Cardiovascular Medicine, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
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Hattori K, Naguro I, Runchel C, Ichijo H. The roles of ASK family proteins in stress responses and diseases. Cell Commun Signal 2009; 7:9. [PMID: 19389260 PMCID: PMC2685135 DOI: 10.1186/1478-811x-7-9] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 04/24/2009] [Indexed: 11/18/2022] Open
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is a member of the mitogen-activated protein kinase kinase kinase family, which activates c-Jun N-terminal kinase and p38 in response to a diverse array of stresses such as oxidative stress, endoplasmic reticulum stress and calcium influx. In the past decade, various regulatory mechanisms of ASK1 have been elucidated, including its oxidative stress-dependent activation. Recently, it has emerged that ASK family proteins play key roles in cancer, cardiovascular diseases and neurodegenerative diseases. In this review, we summarize the recent findings on ASK family proteins and their implications in various diseases.
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Affiliation(s)
- Kazuki Hattori
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Ferrario C. Effect of angiotensin receptor blockade on endothelial function: focus on olmesartan medoxomil. Vasc Health Risk Manag 2009; 5:301-14. [PMID: 19436655 PMCID: PMC2672444 DOI: 10.2147/vhrm.s3141] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Endothelial dysfunction is the common link between cardiovascular disease risk factors and the earliest event in the cascade of incidents that results in target organ damage. Angiotensin II, the terminal pressor effector arm of the renin-angiotensin-aldosterone system, increases blood pressure (BP) by vasoconstriction and sodium and fluid retention, and has a pro-oxidative action that induces endothelial dysfunction and contributes to vascular remodeling. Angiotensin receptor blockers (ARBs) reduce BP and morbidity and mortality in patients with hypertension, ventricular hypertrophy, diabetes mellitus, and renal disease. Olmesartan medoxomil is a long-acting, well-tolerated, effective ARB that prevents or reverses endothelial dysfunction in animal models of atherosclerosis, hypertension, diabetes, nephropathy, and retinopathy. Olmesartan medoxomil, a prodrug of olmesartan approved for the treatment of hypertension, has been shown to ameliorate endothelial dysfunction in patients with hypertension or diabetes. In randomized studies, the drug reduces vascular inflammation and the volume of large atherosclerotic plaques, increases the number of regenerative endothelial progenitor cells in the peripheral circulation, improves endothelium-dependent relaxation, and restores the normal resistance vessel morphology. Importantly, the impact of olmesartan medoxomil on endothelial dysfunction is thought to be independent of BP lowering.
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Affiliation(s)
- Carlos Ferrario
- Hypertension and Vascular Disease Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1032, USA.
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