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Hypoglycaemia aggravates impaired endothelial-dependent vasodilation in diabetes by suppressing endothelial nitric oxide synthase activity and stimulating inducible nitric oxide synthase expression. Microvasc Res 2023; 146:104468. [PMID: 36513147 DOI: 10.1016/j.mvr.2022.104468] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/16/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Diabetes exacerbates vascular injury by triggering endothelial dysfunction. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) both play major roles in endothelial dysfunction. However, effects of hypoglycaemia, the main complication of the insulin therapy to the glycemic control in diabetes, on eNOS activity and iNOS expression, and underlying mechanisms in diabetes remain unknown. Hence, we aimed to determine the effects of hypoglycaemia on eNOS activity and iNOS expression in different arterial beds of diabetic rats. METHODS Sprague-Dawley rats were subjected to Streptozotocin (STZ) combined with high fat diet (HFD) to induce diabetes and then received insulin injection to attain acute and recurrent hypoglycaemia. Immunoblotting was used to analyse the phosphorylation and O-glycosylation status of eNOS and iNOS level from thoracic aorta and mesenteric artery tissue. Indicators of oxidative stress from plasm were determined, and endothelial-dependent vasodilation was detected via wire myograph system. RESULTS Hypoglycaemia was associated with a marked increase in eNOS O-GlcNAcylation and decrease in Serine (Ser)-1177 phosphorylation from thoracic aortas and mesenteric arteries. Moreover, hypoglycaemia resulted in elevated phosphorylation of eNOS at Threonine (Thr)-495 site in mesenteric arteries. Besides, changes in these post-translational modifications were associated with increased O-GlcNAc transferase (OGT), decreased phosphorylation of Akt at Ser-473, and increased protein kinase C α subunit (PKCα). iNOS expression was induced in hypoglycaemia. Furthermore, endothelial-dependent vasodilation was impaired under insulin-induced hypoglycaemia, and further in recurrent hypoglycaemia. CONCLUSIONS Conclusively, these findings strongly indicate that hypoglycaemia-dependent vascular dysfunction in diabetes is mediated through altered eNOS activity and iNOS expression. Therefore, this implies that therapeutic modulation of eNOS activity and iNOS expression in diabetics under intensive glucose control may prevent and treat adverse cardiovascular events.
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Rho-Proteins and Downstream Pathways as Potential Targets in Sepsis and Septic Shock: What Have We Learned from Basic Research. Cells 2021; 10:cells10081844. [PMID: 34440613 PMCID: PMC8391638 DOI: 10.3390/cells10081844] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/09/2021] [Accepted: 07/15/2021] [Indexed: 01/19/2023] Open
Abstract
Sepsis and septic shock are associated with acute and sustained impairment in the function of the cardiovascular system, kidneys, lungs, liver, and brain, among others. Despite the significant advances in prevention and treatment, sepsis and septic shock sepsis remain global health problems with elevated mortality rates. Rho proteins can interact with a considerable number of targets, directly affecting cellular contractility, actin filament assembly and growing, cell motility and migration, cytoskeleton rearrangement, and actin polymerization, physiological functions that are intensively impaired during inflammatory conditions, such as the one that occurs in sepsis. In the last few decades, Rho proteins and their downstream pathways have been investigated in sepsis-associated experimental models. The most frequently used experimental design included the exposure to bacterial lipopolysaccharide (LPS), in both in vitro and in vivo approaches, but experiments using the cecal ligation and puncture (CLP) model of sepsis have also been performed. The findings described in this review indicate that Rho proteins, mainly RhoA and Rac1, are associated with the development of crucial sepsis-associated dysfunction in different systems and cells, including the endothelium, vessels, and heart. Notably, the data found in the literature suggest that either the inhibition or activation of Rho proteins and associated pathways might be desirable in sepsis and septic shock, accordingly with the cellular system evaluated. This review included the main findings, relevance, and limitations of the current knowledge connecting Rho proteins and sepsis-associated experimental models.
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Ustunova S, Takir S, Yilmazer N, Bulut H, Altindirek D, Ng OH, Tansel CD, Dogan BSU, Ozbek U, Armutak EI, Gurevin EG. Hydrogen Sulphide and Nitric Oxide Cooperate in Cardioprotection Against Ischemia/Reperfusion Injury in Isolated Rat Heart. In Vivo 2021; 34:2507-2516. [PMID: 32871779 DOI: 10.21873/invivo.12067] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND/AIM This study was designed to provide further evidence for the interactions between hydrogen sulfide (H2S) and nitric oxide (NO) in ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS Rat hearts were studied with the Langendorff technique using the H2S donor sodium hydrosulfide (NaHS, 40 μM) and the cystathionine gamma-lyase (CTH or CSE) inhibitor DL-propargylglycine (PAG, 1 mM). NO synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME, 30 mg/kg, 7 days) was administered before the isolation. The hearts were homogenized for biochemical and molecular analysis. RESULTS NaHS reversed I/R-induced cardiac performance impairment, increased tissue nitric oxide production and decreased tissue markers for cardiac injury, while L-NAME inhibited these effects. The expression of CTH was increased with PAG, which was suppressed by L-NAME. CONCLUSION H2S and NO increase each other's production suggesting their interaction and cooperation in cardioprotection against I/R injury.
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Affiliation(s)
- Savas Ustunova
- Department of Physiology, School of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Selcuk Takir
- Department of Medical Pharmacology, School of Medicine, Giresun University, Giresun, Turkey
| | - Nadim Yilmazer
- Department of Biology, Faculty of Arts and Sciences, Namik Kemal University, Tekirdag, Turkey
| | - Huri Bulut
- Department of Medical Biochemistry, School of Medicine, Istinye University, Istanbul, Turkey
| | - Didem Altindirek
- Department of Genetics, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Ozden Hatirnaz Ng
- Department of Medical Biology, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Cihan Demirci Tansel
- Department of Biology, Faculty of Science, Istanbul University, Istanbul, Turkey
| | - B Sonmez Uydes Dogan
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey
| | - Ugur Ozbek
- Department of Medical Genetics, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Elif Ilkay Armutak
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Ebru Gurel Gurevin
- Department of Biology, Faculty of Science, Istanbul University, Istanbul, Turkey
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Wang TT, Shi MM, Liao XL, Li YQ, Yuan HX, Li Y, Liu X, Ning DS, Peng YM, Yang F, Mo ZW, Jiang YM, Xu YQ, Li H, Wang M, Ou ZJ, Xia Z, Ou JS. Overexpression of inducible nitric oxide synthase in the diabetic heart compromises ischemic postconditioning. J Mol Cell Cardiol 2019; 129:144-153. [PMID: 30797815 DOI: 10.1016/j.yjmcc.2019.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/21/2019] [Accepted: 02/18/2019] [Indexed: 01/07/2023]
Abstract
Ischemia postconditioning (PTC) can reduce myocardial ischemia/reperfusion injury. However, the effectiveness of PTC cardioprotection is reduced or lost in diabetes and the mechanisms are largely unclear. Hyperglycemia can induce overexpression of inducible nitric oxide synthesis (iNOS) in the myocardium of diabetic subjects. However, it is unknown whether or not iNOS especially its overexpression plays an important role in the loss of cardioprotection of PTC in diabetes. C57BL6 and iNOS-/- mice were treated with streptozotocin to induce diabetes. Part of diabetic C57BL6 mice were also treated with an iNOS specific inhibitor, 1400 W. Mice were subjected to myocardial ischemia/ reperfusion with/without PTC. The hemodynamic parameters, plasma levels of cardiac troponin T (cTnT), TNF-α, IL-6 and nitric oxide (NO) were monitored. The myocardial infarct size, superoxide anion (O2-) generation, nitrotyrosine production and apoptosis were measured. The expression of phosphorylated Akt, endothelial NOS (eNOS), iNOS and Erk1/2 in ischemic heart were detected by immunoblot analysis. In diabetic C57BL6 and iNOS-/- mice, the post-ischemic hemodynamics were impaired, the cTnT, TNF-α, IL-6 level, myocardial infarct size, apoptotic index, O2- and nitrotyrosine generation were increased and the Akt/eNOS signal pathways were inhibited. PTC improved hemodynamic parameters, reduced cTnT level, myocardial infarct size, apoptotic index, O2- and nitrotyrosine generation and activated Akt/eNOS and Erk1/2 signal pathways in both non-diabetic C57BL6 and iNOS-/- mice as well as diabetic iNOS-/- mice, but not in diabetic C57BL6 mice. PTC also increased NO production in both non-diabetic and diabetic C57BL6 and iNOS-/- mice, and enhanced iNOS expression in non-diabetic C57BL6 mice. 1400 W restored the cardioprotection of PTC in diabetic C57BL6 mice. Our data demonstrated that PTC reduced myocardial ischemia/reperfusion injury in non-diabetic mice but not C57BL6 diabetic mice. Deletion of iNOS restored the cardioprotection of PTC in diabetic mice. Our findings suggest that iNOS plays a key role in the reduction of cardioprotection of PTC in diabetes and may provide a therapeutic target for diabetic patients.
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Affiliation(s)
- Tian-Tian Wang
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Mao-Mao Shi
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Xiao-Long Liao
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China
| | - Yu-Quan Li
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Hao-Xiang Yuan
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Yan Li
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Xiang Liu
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Da-Sheng Ning
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Yue-Ming Peng
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Fan Yang
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Zhi-Wei Mo
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China
| | - Yu-Mei Jiang
- Department of Extracorporeal circulation, Heart center, The First Affiliated Hospital, Sun Yat-sen University, PR China
| | - Ying-Qi Xu
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China
| | - Haobo Li
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China
| | - Min Wang
- Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, PR China
| | - Zhi-Jun Ou
- Division of Hypertension and Vascular Diseases, Heart Center, The First Affiliated Hospital, Sun Yat-sen University, PR China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China.
| | - Zhengyuan Xia
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China.
| | - Jing-Song Ou
- Division of Cardiac Surgery, Heart center, The First Affiliated Hospital, Sun Yat-sen University, China; NHC Key Laboratory of Assisted Circulation, Sun Yat-sen University, PR China; National and Guangdong Province Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases, PR China; Guangdong Provincial Key Laboratory of Brain Function and Disease, Guangzhou 510080, PR China.
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Chen H, Chen X, Luo Y, Shen J. Potential molecular targets of peroxynitrite in mediating blood–brain barrier damage and haemorrhagic transformation in acute ischaemic stroke with delayed tissue plasminogen activator treatment. Free Radic Res 2018; 52:1220-1239. [PMID: 30468092 DOI: 10.1080/10715762.2018.1521519] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hansen Chen
- School of Chinese Medicine, the University of Hong Kong, PR China
- Shenzhen Institute of Research and Innovation (HKU-SIRI), University of Hong Kong, Hong Kong, PR China
| | - Xi Chen
- Department of Core Facility, the People’s Hospital of Bao-an Shenzhen, Shenzhen, PR China
- The 8th People’s Hospital of Shenzhen, the Affiliated Bao-an Hospital of Southern Medical University, Shenzhen, PR China
| | - Yunhao Luo
- School of Chinese Medicine, the University of Hong Kong, PR China
| | - Jiangang Shen
- School of Chinese Medicine, the University of Hong Kong, PR China
- Shenzhen Institute of Research and Innovation (HKU-SIRI), University of Hong Kong, Hong Kong, PR China
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Sartoretto SM, Santos FF, Costa BP, Ceravolo GS, Santos-Eichler R, Carvalho MHC, Fortes ZB, Akamine EH. Involvement of inducible nitric oxide synthase and estrogen receptor ESR2 (ERβ) in the vascular dysfunction in female type 1 diabetic rats. Life Sci 2018; 216:279-286. [PMID: 30447304 DOI: 10.1016/j.lfs.2018.11.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/31/2018] [Accepted: 11/13/2018] [Indexed: 11/25/2022]
Abstract
AIMS Inflammation is involved in diabetes-related vascular dysfunction. Estrogen receptor ESR2/ERβ induces the expression of inducible nitric oxide (NO) synthase (iNOS) and inflammation. The present study investigated the effect of alloxan-induced type 1 diabetes on the iNOS and ESR2 expression and the effect of the chronic iNOS inhibition on the vascular smooth muscle dysfunction in diabetic female rats. In addition, we evaluated the involvement of ESR2 in iNOS expression. MAIN METHODS Alloxan-induced diabetic female rats were treated or not with iNOS inhibitor (L-NIL). iNOS and ESR2 immunostaining, S-nitrosylated proteins and IL-1β protein expression in aorta and plasmatic NO levels were analyzed. Contractile response to noradrenaline was analyzed in endothelium-denuded aorta. iNOS mRNA expression was analyzed in isolated aortic smooth muscle cells (ASMCs) of female rats, incubated with 22 mM glucose and an ESR2 antagonist. KEY FINDINGS Aortic iNOS and ESR2 immunostaining, S-nitrosylated proteins, IL-1β protein expression and plasmatic NO levels were all increased, whereas noradrenaline-induced contraction was reduced in aorta of diabetic female rats. With the exception of iNOS and ESR2 immunostaining, all these parameters were corrected by L-NIL treatment. High glucose increased iNOS mRNA expression in ASMCs, which was reduced by an ESR2 antagonist. SIGNIFICANCE We demonstrated that increased iNOS-NO contributed to the impairment of the contractile response of aortic smooth muscle cells in female type 1 diabetic rats and that increased expression of iNOS may involve the participation of ESR2/ERβ.
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Affiliation(s)
- Simone Marcieli Sartoretto
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Fernanda Fernandes Santos
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Beatriz Pereira Costa
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Graziela Scalianti Ceravolo
- Department of Physiological Sciences, Biological Sciences Center, State University of Londrina, Paraná, Brazil
| | - Rosângela Santos-Eichler
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - Zuleica Bruno Fortes
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Eliana Hiromi Akamine
- Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Song X, He R, Han W, Li T, Xie L, Cheng L, Chen H, Xie M, Jiang L. Protective effects of the ROCK inhibitor fasudil against cognitive dysfunction following status epilepticus in male rats. J Neurosci Res 2018; 97:506-519. [PMID: 30421453 DOI: 10.1002/jnr.24355] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/30/2018] [Accepted: 10/17/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Xiaojie Song
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
- Department of Neurology Children’s Hospital of Chongqing Medical University Chongqing China
| | - Rong He
- Pediatric department University‐Town Hospital of Chongqing Medical University Chongqing China
| | - Wei Han
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
| | - Tianyi Li
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
- Department of Neurology Children’s Hospital of Chongqing Medical University Chongqing China
| | - Lingling Xie
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
- Department of Neurology Children’s Hospital of Chongqing Medical University Chongqing China
| | - Li Cheng
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
| | - Hengsheng Chen
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
| | - Mingdan Xie
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
| | - Li Jiang
- Pediatric Research Institute Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics Chongqing China
- Department of Neurology Children’s Hospital of Chongqing Medical University Chongqing China
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Martin B, Caron N, Jadot I, Colombaro V, Federici G, Depommier C, Declèves AÉ. Evaluation of inducible nitric oxide synthase inhibition on kidney function and structure in high-fat diet-induced kidney disease. Exp Physiol 2017; 103:125-140. [PMID: 28944982 DOI: 10.1113/ep086594] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 08/25/2017] [Indexed: 12/15/2022]
Abstract
NEW FINDINGS What is the central question of this study? The metabolic pathways regulating the effects of obesity on the kidney remain unknown. We sought to determine whether inducible nitric oxide synthase (iNOS) is involved in the underlying mechanisms of high-fat diet-induced kidney disease using a specific iNOS inhibitor, N6-(1-iminoethyl)-l-lysine hydrochloride (L-NIL). What is the main finding and its importance? We did not demonstrate an upregulation of iNOS renal expression after high caloric intake, suggesting that iNOS might not be a crucial player in the development of obesity-induced kidney disease. Although L-NIL treatment clearly ameliorated systemic metabolic parameters, the effect on loss of renal function, impairment of tubular integrity, oxidative stress and inflammation appeared to be more moderate. Central obesity is related to caloric excess, promoting deleterious cellular responses in targeted organs. Nitric oxide (NO) has been determined as a key player in the pathogenesis of metabolic diseases. Here, we investigated the implication of inducible NO synthase (iNOS) in the development of obesity-induced kidney disease. C57Bl/6 male mice were randomized to a low-fat diet (LFD) or a high-fat diet (HFD) and treated with N6-(1-iminoethyl)-l-lysine hydrochloride (L-NIL), a specific iNOS inhibitor, for 16 weeks. Mice fed an HFD exhibited a significant increase in body weight, fasting blood glucose and plasma concentrations of non-esterified fatty acids, triglyceride and insulin. Inhibition of iNOS prevented these changes in mice fed an HFD. Interestingly, the significant increase in albuminuria and mesangial matrix expansion were not ameliorated with L-NIL, whereas a significant decrease in proteinuria, N-acetyl-β-d-glucosaminidase excretion and renal triglyceride content were found, suggesting that iNOS inhibition is more suitable for tubular function than glomerular function. The urinary concentration of hydrogen peroxide, a stable product of reactive oxygen species production, that was found to be increased in mice fed an HFD, was significantly reduced with L-NIL. Finally, despite a moderate effect of L-NIL on inflammatory processes in the kidney, we demonstrated a positive impact of this treatment on adipocyte hypertrophy and on adipose tissue inflammation. These results suggest that inhibition of iNOS leads to a moderate beneficial effect on kidney function in mice fed an HFD. Further studies are needed for better understanding of the role of iNOS in obesity-induced kidney disease.
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Affiliation(s)
- Blanche Martin
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium
| | - Nathalie Caron
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium
| | - Inès Jadot
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium
| | - Vanessa Colombaro
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium
| | - Gabrielle Federici
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium
| | - Clara Depommier
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium
| | - Anne-Émilie Declèves
- Molecular Physiology Research Unit-URPHYM, University of Namur (UNamur), Namur, Belgium.,Laboratory of Molecular Biology, University of Mons (UMONS), Mons, Belgium
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Yang R, Jia Q, Liu XF, Wang YY, Ma SF. Effects of hydrogen sulfide on inducible nitric oxide synthase activity and expression of cardiomyocytes in diabetic rats. Mol Med Rep 2017; 16:5277-5284. [PMID: 28849194 PMCID: PMC5647082 DOI: 10.3892/mmr.2017.7247] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 08/08/2017] [Indexed: 01/08/2023] Open
Abstract
The aim of the present study was to investigate the effects of hydrogen sulfide (H2S) on the activity and expression of inducible nitric oxide synthase (iNOS) in the myocardial tissue of type 1 diabetic rats. Rats were divided randomly into four groups: Normal control (NC), diabetes mellitus (DM), DM+DL-Proparglygylcine (DM+PAG) and DM+sodium hydrosulfide (DM+NaHS) groups. Type 1 diabetes was induced in the respective groups by a single intraperitoneal (i.p.) injection of streptozotocin. Rats in the DM+PAG and DM+NaHS groups were injected with PAG and NaHS (i.p.) once a day, respectively. The level of fasting blood glucose (FBG), the heart-weight to body-weight (HW/BW) ratio and the ventricular hemodynamic parameters were measured. The activities of serum total NOS (tNOS), iNOS, lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase MB isozyme (CK-MB), and the content of nitric oxide (NO) were detected. The contents of myocardial malondialdehyde (MDA) and NO, and the activities of superoxide dismutase (SOD), tNOS and iNOS were determined. The myocardial tissue was examined for histological and ultrastructural alterations. The expression level of iNOS at the transcriptional and translational levels in the myocardial tissue was estimated. The level of FBG was increased in the DM group compared with the NC group, verifying the diabetic condition of the rats. The function of the left ventricle, the myocardial histological alterations and ultrastructures were damaged in the DM group. The DM group additionally demonstrated an increase in the serum NO content and tNOS, iNOS, LDH, CK and CK-MB activities. The myocardial MDA, NO content and tNOS levels were additionally increased in this group. The iNOS activity was increased significantly whereas the myocardial SOD activity was decreased. The increase in the iNOS activity was supported by an enhanced expression level of myocardial iNOS mRNA and protein in the DM group. In the DM+PAG group, in the absence of H2S, the dysfunction of the left ventricle and the oxidative stress injury were increased compared with the DM group. The activity and the expression of tNOS and iNOS were increased significantly. However, the rats in the DM+PAG group demonstrated the opposite effects. In conclusion, H2S exhibits a protective effect on the myocardium in type 1 diabetic rats, which may be associated with the suppression of iNOS activity and expression, a decrease in the NO content and the inhibition of oxidative stress injury.
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Affiliation(s)
- Rui Yang
- Department of Physiology, Bengbu Medical College, Bengbu, Anhui 233030, P.R. China
| | - Qiang Jia
- Department of Physiology, Bengbu Medical College, Bengbu, Anhui 233030, P.R. China
| | - Xiao-Fen Liu
- Department of Physiology, Bengbu Medical College, Bengbu, Anhui 233030, P.R. China
| | - Yuan-Yuan Wang
- Center of Functional Experiment, Bengbu Medical College, Bengbu, Anhui 233030, P.R. China
| | - Shan-Feng Ma
- Department of Physiology, Bengbu Medical College, Bengbu, Anhui 233030, P.R. China
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Changes in cardiac Na +/K +-ATPase expression and activity in female rats fed a high-fat diet. Mol Cell Biochem 2017; 436:49-58. [PMID: 28567564 DOI: 10.1007/s11010-017-3077-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/25/2017] [Indexed: 12/27/2022]
Abstract
The aim of this study was to investigate whether the presence of endogenous estradiol alters the effects of a high-fat (HF) diet on activity/expression of the cardiac Na+/K+-ATPase, via PI3K/IRS and RhoA/ROCK signalling cascades in female rats. For this study, female Wistar rats (8 weeks old, 150-200 g) were fed a standard diet or a HF diet (balanced diet for laboratory rats enriched with 42% fat) for 10 weeks. The results show that rats fed a HF diet exhibited a decrease in phosphorylation of the α1 subunit of Na+/K+-ATPase by 30% (p < 0.05), expression of total α1 subunit of Na+/K+-ATPase by 31% (p < 0.05), and association of IRS1 with p85 subunit of PI3K by 42% (p < 0.05), while the levels of cardiac RhoA and ROCK2 were significantly increased by 84% (p < 0.01) and 62% (p < 0.05), respectively. Our results suggest that a HF diet alters cardiac Na+/K+-ATPase expression via molecular mechanisms involving RhoA/ROCK and IRS-1/PI3K signalling in female rats.
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Zurita E, Huerta M, De Jesús L, La Cruz FD, Ortiz-Butron R, Flores G, Gómez-Villalobos MDJ. Cerebrolysin Effects on Cardiac Neuropathy in Diabetic Rats. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/pp.2017.87015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Sun Z, Wu X, Li W, Peng H, Shen X, Ma L, Liu H, Li H. RhoA/rock signaling mediates peroxynitrite-induced functional impairment of Rat coronary vessels. BMC Cardiovasc Disord 2016; 16:193. [PMID: 27724862 PMCID: PMC5057502 DOI: 10.1186/s12872-016-0372-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 09/28/2016] [Indexed: 01/03/2023] Open
Abstract
Background Diabetes-induced vascular dysfunction may arise from reduced nitric oxide (NO) availability, following interaction with superoxide to form peroxynitrite. Peroxynitrite can induce formation of 3-nitrotyrosine-modified proteins. RhoA/ROCK signaling is also involved in diabetes-induced vascular dysfunction. The study aimed to investigate possible links between Rho/ROCK signaling, hyperglycemia, and peroxynitrite in small coronary arteries. Methods Rat small coronary arteries were exposed to normal (NG; 5.5 mM) or high (HG; 23 mM) D-glucose. Vascular ring constriction to 3 mM 4-aminopyridine and dilation to 1 μM forskolin were measured. Protein expression (immunohistochemistry and western blot), mRNA expression (real-time PCR), and protein activity (luminescence-based G-LISA and kinase activity spectroscopy assays) of RhoA, ROCK1, and ROCK2 were determined. Results Vascular ring constriction and dilation were smaller in the HG group than in the NG group (P < 0.05); inhibition of RhoA or ROCK partially reversed the effects of HG. Peroxynitrite impaired vascular ring constriction/dilation; this was partially reversed by inhibition of RhoA or ROCK. Protein and mRNA expressions of RhoA, ROCK1, and ROCK2 were higher under HG than NG (P < 0.05). This HG-induced upregulation was attenuated by inhibition of RhoA or ROCK (P < 0.05). HG increased RhoA, ROCK1, and ROCK2 activity (P < 0.05). Peroxynitrite also enhanced RhoA, ROCK1, and ROCK2 activity; these actions were partially inhibited by 100 μM urate (peroxynitrite scavenger). Exogenous peroxynitrite had no effect on the expression of the voltage-dependent K+ channels 1.2 and 1.5. Conclusions Peroxynitrite-induced coronary vascular dysfunction may be mediated, at least in part, through increased expressions and activities of RhoA, ROCK1, and ROCK2.
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Affiliation(s)
- Zhijun Sun
- Department of Heart Center, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China
| | - Xing Wu
- Department of Heart Center, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China
| | - Weiping Li
- Department of Heart Center, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China
| | - Hui Peng
- Department of Heart Center, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China
| | - Xuhua Shen
- Department of Heart Center, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China
| | - Lu Ma
- Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Beijing, People's Republic of China
| | - Huirong Liu
- Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Beijing, People's Republic of China
| | - Hongwei Li
- Department of Heart Center, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China.
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The Rho kinase inhibitor, fasudil, ameliorates diabetes-induced cardiac dysfunction by improving calcium clearance and actin remodeling. J Mol Med (Berl) 2016; 95:155-165. [PMID: 27576917 DOI: 10.1007/s00109-016-1469-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 02/07/2023]
Abstract
Previous study showed inhibition of RhoA and Rho kinase (ROCK) activity with fasudil could alleviate diabetes-induced cardiac dysfunction partially due to improvement of myocardial fibrosis. However, the effect of fasudil on intracellular calcium cycling and actin remodeling, both of which are important to regulate excitation-contract coupling, is still not fully elucidated. In this study, a diabetic cardiomyopathy model was induced by a single intraperitoneal injection of streptozotocin (STZ) in male Sprague Dawley rats. Diabetic rats were treated with fasudil or placebo for 8 weeks. We found that long-term administration of fasudil, a specific Rho kinase inhibitor, significantly ameliorated diabetes-induced contractile dysfunction both at cellular and whole organ levels. Fasudil-treated rats displayed improved diastolic intracellular calcium ([Ca2+]i) removal and rescued expression of protein responsible for [Ca2+]i clearance. Furthermore, our study indicated that fasudil treatment normalized the phosphorylation of the PKCβ2/Akt pathway in the diabetic heart, which might be the underlying mechanism accounting for the protective effect of fasudil on [Ca2+]i clearance. In addition, compared to the diabetes group, fasudil also normalized the G/F-actin ratio by preventing cofilin phosphorylation and promoted F-actin organization, suggesting a beneficial effect on actin remodeling. These findings indicate the protective effect of fasudil against diabetes-induced cardiac dysfunction via modulation of Ca2+ handling and actin remodeling. Overactivation of RhoA/ROCK plays a key role in the development of DCM. Inhibition of ROCK activity with fasudil improved [Ca2+]i removal in diabetic cardiomyocytes. Fasudil normalized the G/F-actin ratio and promoted F-actin organization. ROCK may be an excellent therapeutic target for the treatment of DCM. KEY MESSAGE Overactivation of RhoA/ROCK plays a key role in the development of DCM. Inhibition of ROCK activity with fasudil improved [Ca2+]i removal in diabetic cardiomyocytes. Fasudil normalized the G/F-actin ratio and promoted F-actin organization. ROCK may be an excellent therapeutic target for the treatment of DCM.
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Kleindienst A, Battault S, Belaidi E, Tanguy S, Rosselin M, Boulghobra D, Meyer G, Gayrard S, Walther G, Geny B, Durand G, Cazorla O, Reboul C. Exercise does not activate the β3 adrenergic receptor–eNOS pathway, but reduces inducible NOS expression to protect the heart of obese diabetic mice. Basic Res Cardiol 2016; 111:40. [DOI: 10.1007/s00395-016-0559-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/03/2016] [Indexed: 02/08/2023]
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Waddingham MT, Edgley AJ, Astolfo A, Inagaki T, Fujii Y, Du CK, Zhan DY, Tsuchimochi H, Yagi N, Kelly DJ, Shirai M, Pearson JT. Chronic Rho-kinase inhibition improves left ventricular contractile dysfunction in early type-1 diabetes by increasing myosin cross-bridge extension. Cardiovasc Diabetol 2015; 14:92. [PMID: 26194354 PMCID: PMC4509700 DOI: 10.1186/s12933-015-0256-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/25/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Impaired actin-myosin cross-bridge (CB) dynamics correlate with impaired left ventricular (LV) function in early diabetic cardiomyopathy (DCM). Elevated expression and activity of Rho kinase (ROCK) contributes to the development of DCM. ROCK targets several sarcomeric proteins including myosin light chain 2, myosin binding protein-C (MyBP-C), troponin I (TnI) and troponin T that all have important roles in regulating CB dynamics and contractility of the myocardium. Our aim was to examine if chronic ROCK inhibition prevents impaired CB dynamics and LV dysfunction in a rat model of early diabetes, and whether these changes are associated with changes in myofilament phosphorylation state. METHODS Seven days post-diabetes induction (65 mg/kg ip, streptozotocin), diabetic rats received the ROCK inhibitor, fasudil (10 mg/kg/day ip) or vehicle for 14 days. Rats underwent cardiac catheterization to assess LV function simultaneous with X-ray diffraction using synchrotron radiation to assess in situ CB dynamics. RESULTS Compared to controls, diabetic rats developed mild systolic and diastolic dysfunction, which was attenuated by fasudil. End-diastolic and systolic myosin proximity to actin filaments were significantly reduced in diabetic rats (P < 0.05). In all rats there was an inverse correlation between ROCK1 expression and the extension of myosin CB in diastole, with the lowest ROCK expression in control and fasudil-treated diabetic rats. In diabetic and fasudil-treated diabetic rats changes in relative phosphorylation of TnI and MyBP-C were not significant from controls. CONCLUSIONS Our results demonstrate a clear role for ROCK in the development of LV dysfunction and impaired CB dynamics in early DCM.
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Affiliation(s)
- Mark T Waddingham
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia.
| | - Amanda J Edgley
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia. .,Department of Physiology, Monash University, Clayton, VIC, Australia.
| | - Alberto Astolfo
- Australian Synchrotron, Clayton, VIC, Australia. .,Department of Medical Physics and Bioengineering, University College of London, London, England, UK.
| | - Tadakatsu Inagaki
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - Yutaka Fujii
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - Cheng-Kun Du
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - Dong-Yun Zhan
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - Naoto Yagi
- Japan Synchrotron Radiation Research Institute, Harima, Hyogo, Japan.
| | - Darren J Kelly
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia.
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
| | - James T Pearson
- Department of Physiology, Monash University, Clayton, VIC, Australia. .,Australian Synchrotron, Clayton, VIC, Australia. .,Monash Biomedical Imaging Facility, Monash University, Clayton, VIC, Australia.
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Murfitt L, Whiteley G, Iqbal MM, Kitmitto A. Targeting caveolin-3 for the treatment of diabetic cardiomyopathy. Pharmacol Ther 2015; 151:50-71. [PMID: 25779609 DOI: 10.1016/j.pharmthera.2015.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 12/21/2022]
Abstract
Diabetes is a global health problem with more than 550 million people predicted to be diabetic by 2030. A major complication of diabetes is cardiovascular disease, which accounts for over two-thirds of mortality and morbidity in diabetic patients. This increased risk has led to the definition of a diabetic cardiomyopathy phenotype characterised by early left ventricular dysfunction with normal ejection fraction. Here we review the aetiology of diabetic cardiomyopathy and explore the involvement of the protein caveolin-3 (Cav3). Cav3 forms part of a complex mechanism regulating insulin signalling and glucose uptake, processes that are impaired in diabetes. Further, Cav3 is key for stabilisation and trafficking of cardiac ion channels to the plasma membrane and so contributes to the cardiac action potential shape and duration. In addition, Cav3 has direct and indirect interactions with proteins involved in excitation-contraction coupling and so has the potential to influence cardiac contractility. Significantly, both impaired contractility and rhythm disturbances are hallmarks of diabetic cardiomyopathy. We review here how changes to Cav3 expression levels and altered relationships with interacting partners may be contributory factors to several of the pathological features identified in diabetic cardiomyopathy. Finally, the review concludes by considering ways in which levels of Cav3 may be manipulated in order to develop novel therapeutic approaches for treating diabetic cardiomyopathy.
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Affiliation(s)
- Lucy Murfitt
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, M13 9NT, UK
| | - Gareth Whiteley
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, M13 9NT, UK
| | - Mohammad M Iqbal
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, M13 9NT, UK
| | - Ashraf Kitmitto
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, M13 9NT, UK.
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Karabulut D, Ulusoy HB, Kaymak E, Sönmez MF. Therapeutic effects of pentoxifylline on diabetic heart tissue via NOS. Anatol J Cardiol 2015; 16:310-5. [PMID: 26488377 PMCID: PMC5336777 DOI: 10.5152/akd.2015.6252] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Objective: Diabetes mellitus causes a decrease in cardiac output, arterial blood pressure, and heart rate. In this study, we aimed to investigate, at the molecular level, the effect of nitric oxide synthase (NOS) on heart pathology in type 1 diabetes and look at the therapeutic effect of pentoxifylline on this pathology. Methods: In this experimental study, 50 Wistar albino male rats were used. The rats were divided into 5 groups: group C, control; group D, only diabetes; group D+PI and D+PII, diabetes + pentoxifylline; group P, only pentoxifylline. Group D+PI rats received 50 mg/kg/day pentoxifylline over two months. However, group D+PII rats received saline in the first month and 50 mg/kg/day of pentoxifylline over the following month. At the end of two months, NOS expressions in heart tissue were assessed through immunohistochemistry analysis. The data were compared by one-way ANOVA. Results: At the end of the experiments, there was increased cytoplasmic vacuolization, myofibrillar loss, cytoplasmic eosinophilia, and degeneration of cardiomyocytes; nNOS and iNOS expressions in group D decreased compared with that in group C. In group D+PI and group D+PII, nNOS and iNOS expressions improved compared with group D. Conclusion: As a result, we found that diabetes, a known chronic disease, causes serious damage in heart tissue. NOS plays a role in this damage, and pentoxifylline aided in improving nNOS and iNOS expression in this damage.
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Affiliation(s)
- Derya Karabulut
- Department of Histology and Embryology, Faculty of Medicine, Erciyes University; Kayseri-Turkey.
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Varga ZV, Giricz Z, Liaudet L, Haskó G, Ferdinandy P, Pacher P. Interplay of oxidative, nitrosative/nitrative stress, inflammation, cell death and autophagy in diabetic cardiomyopathy. Biochim Biophys Acta Mol Basis Dis 2014; 1852:232-42. [PMID: 24997452 DOI: 10.1016/j.bbadis.2014.06.030] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/11/2014] [Accepted: 06/24/2014] [Indexed: 12/26/2022]
Abstract
Diabetes is a recognized risk factor for cardiovascular diseases and heart failure. Diabetic cardiovascular dysfunction also underscores the development of diabetic retinopathy, nephropathy and neuropathy. Despite the broad availability of antidiabetic therapy, glycemic control still remains a major challenge in the management of diabetic patients. Hyperglycemia triggers formation of advanced glycosylation end products (AGEs), activates protein kinase C, enhances polyol pathway, glucose autoxidation, which coupled with elevated levels of free fatty acids, and leptin have been implicated in increased generation of superoxide anion by mitochondria, NADPH oxidases and xanthine oxidoreductase in diabetic vasculature and myocardium. Superoxide anion interacts with nitric oxide forming the potent toxin peroxynitrite via diffusion limited reaction, which in concert with other oxidants triggers activation of stress kinases, endoplasmic reticulum stress, mitochondrial and poly(ADP-ribose) polymerase 1-dependent cell death, dysregulates autophagy/mitophagy, inactivates key proteins involved in myocardial calcium handling/contractility and antioxidant defense, activates matrix metalloproteinases and redox-dependent pro-inflammatory transcription factors (e.g. nuclear factor kappaB) promoting inflammation, AGEs formation, eventually culminating in myocardial dysfunction, remodeling and heart failure. Understanding the complex interplay of oxidative/nitrosative stress with pro-inflammatory, metabolic and cell death pathways is critical to devise novel targeted therapies for diabetic cardiomyopathy, which will be overviewed in this brief synopsis. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.
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Affiliation(s)
- Zoltán V Varga
- Laboratory of Physiological Studies, National Institutes of Health/NIAAA, Bethesda, MD, USA; Cardiometabolic Research Group, Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Zoltán Giricz
- Cardiometabolic Research Group, Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Lucas Liaudet
- Department of Intensive Care Medicine BH 08-621-University Hospital Medical Center 1011 LAUSANNE Switzerland
| | - György Haskó
- Department of Surgery and Center for Immunity and Inflammation, Rutgers NJ Medical School, USA
| | - Peter Ferdinandy
- Cardiometabolic Research Group, Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary; Pharmahungary Group, Szeged, Hungary
| | - Pál Pacher
- Laboratory of Physiological Studies, National Institutes of Health/NIAAA, Bethesda, MD, USA.
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Ho YJ, Lee AS, Chen WP, Chang WL, Tsai YK, Chiu HL, Kuo YH, Su MJ. Caffeic acid phenethyl amide ameliorates ischemia/reperfusion injury and cardiac dysfunction in streptozotocin-induced diabetic rats. Cardiovasc Diabetol 2014; 13:98. [PMID: 24923878 PMCID: PMC4065079 DOI: 10.1186/1475-2840-13-98] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 05/26/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Caffeic acid phenethyl ester (CAPE) has been shown to protect the heart against ischemia/reperfusion (I/R) injury by various mechanisms including its antioxidant effect. In this study, we evaluated the protective effects of a CAPE analog with more structural stability in plasma, caffeic acid phenethyl amide (CAPA), on I/R injury in streptozotocin (STZ)-induced type 1 diabetic rats. METHODS Type 1 diabetes mellitus was induced in Sprague-Dawley rats by a single intravenous injection of 60 mg/kg STZ. To produce the I/R injury, the left anterior descending coronary artery was occluded for 45 minutes, followed by 2 hours of reperfusion. CAPA was pretreated intraperitoneally 30 minutes before reperfusion. An analog devoid of the antioxidant property of CAPA, dimethoxyl CAPA (dmCAPA), and a nitric oxide synthase (NOS) inhibitor (Nω-nitro-l-arginine methyl ester [l-NAME]) were used to evaluate the mechanism involved in the reduction of the infarct size following CAPA-treatment. Finally, the cardioprotective effect of chronic treatment of CAPA was analyzed in diabetic rats. RESULTS Compared to the control group, CAPA administration (3 and 15 mg/kg) significantly reduced the myocardial infarct size after I/R, while dmCAPA (15 mg/kg) had no cardioprotective effect. Interestingly, pretreatment with a NOS inhibitor, (L-NAME, 3 mg/kg) eliminated the effect of CAPA on myocardial infarction. Additionally, a 4-week CAPA treatment (1 mg/kg, orally, once daily) started 4 weeks after STZ-induction could effectively decrease the infarct size and ameliorate the cardiac dysfunction by pressure-volume loop analysis in STZ-induced diabetic animals. CONCLUSIONS CAPA, which is structurally similar to CAPE, exerts cardioprotective activity in I/R injury through its antioxidant property and by preserving nitric oxide levels. On the other hand, chronic CAPA treatment could also ameliorate cardiac dysfunction in diabetic animals.
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Affiliation(s)
| | | | | | | | | | | | | | - Ming-Jai Su
- Department of Pharmacology, College of Medicine, National Taiwan University, 11F, No, 1, Sec, 1, Jen-Ai Road, Taipei 10051, Taiwan.
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Simon JN, Duglan D, Casadei B, Carnicer R. Nitric oxide synthase regulation of cardiac excitation-contraction coupling in health and disease. J Mol Cell Cardiol 2014; 73:80-91. [PMID: 24631761 DOI: 10.1016/j.yjmcc.2014.03.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 02/07/2023]
Abstract
Significant advances in our understanding of the ability of nitric oxide synthases (NOS) to modulate cardiac function have provided key insights into the role NOS play in the regulation of excitation-contraction (EC) coupling in health and disease. Through both cGMP-dependent and cGMP-independent (e.g. S-nitrosylation) mechanisms, NOS have the ability to alter intracellular Ca(2+) handling and the myofilament response to Ca(2+), thereby impacting the systolic and diastolic performance of the myocardium. Findings from experiments using nitric oxide (NO) donors and NOS inhibition or gene deletion clearly implicate dysfunctional NOS as a critical contributor to many cardiovascular disease states. However, studies to date have only partially addressed NOS isoform-specific effects and, more importantly, how subcellular localization of NOS influences ion channels involved in myocardial EC coupling and excitability. In this review, we focus on the contribution of each NOS isoform to cardiac dysfunction and on the role of uncoupled NOS activity in common cardiac disease states, including heart failure, diabetic cardiomyopathy, ischemia/reperfusion injury and atrial fibrillation. We also review evidence that clearly indicates the importance of NO in cardioprotection. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System".
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Affiliation(s)
- Jillian N Simon
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Drew Duglan
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Barbara Casadei
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Ricardo Carnicer
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford, UK.
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Tong J, Wang Y, Chang B, Zhang D, Liu P, Wang B. Activation of RhoA in alcohol-induced intestinal barrier dysfunction. Inflammation 2014; 36:750-8. [PMID: 23361851 DOI: 10.1007/s10753-013-9601-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ras homolog gene family, member A (RhoA) is a small GTPase protein known to regulate multiple cellular processes. In the present study, we used both an alcohol-fed mouse model and an alcohol-treated Caco-2 intestinal epithelial cell monolayer in vitro model to investigate whether RhoA is involved in alcohol-induced intestinal barrier dysfunction as well as the underlying mechanisms. We found that chronic alcohol exposure significantly increased both intestinal RhoA mRNA and protein levels in mice and alcohol treatment also increased RhoA activity in Caco-2 cells. The alcohol-induced elevation in RhoA activity was accompanied by an increase in inducible nitric oxide synthase (iNOS) expression and prevented by N⁶-(1-iminoethyl)-L-lysine dihydrochloride (L-NIL) or small interfering RNA (siRNA) specific for iNOS. Furthermore, alcohol treatment with Caco-2 cells resulted in a significant decrease in the epithelial transepithelial electrical resistance (TEER) value, which was attenuated by knockdown of RhoA. Taken together, our findings suggest that iNOS-mediated activation of RhoA appears to be one of the important mechanisms contributing to the deleterious effects of alcohol on intestinal barrier function.
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Affiliation(s)
- Jing Tong
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, 155 North Nanjing Street, Shenyang 110001, China
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Pearson JT, Jenkins MJ, Edgley AJ, Sonobe T, Joshi M, Waddingham MT, Fujii Y, Schwenke DO, Tsuchimochi H, Yoshimoto M, Umetani K, Kelly DJ, Shirai M. Acute Rho-kinase inhibition improves coronary dysfunction in vivo, in the early diabetic microcirculation. Cardiovasc Diabetol 2013; 12:111. [PMID: 24059472 PMCID: PMC3734116 DOI: 10.1186/1475-2840-12-111] [Citation(s) in RCA: 30] [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: 07/29/2013] [Accepted: 07/30/2013] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Activation of RhoA/Rho-kinase (ROCK) is increasingly implicated in acute vasospasm and chronic vasoconstriction in major organ systems. Therefore we aimed to ascertain whether an increase in ROCK activity plays a role in the deterioration of coronary vascular function in early stage diabetes. METHODS Synchrotron radiation microangiography was used to determine in vivo coronary responses in diabetic (3 weeks post streptozotocin 65 mg/kg ip) and vehicle treated male Sprague-Dawley rats (n = 8 and 6). Changes in vessel number and calibre during vasodilator stimulation before and after blockade of nitric oxide synthase and cyclooxygenase were compared between rats. Acute responses to ROCK inhibitor, fasudil (10 mg/kg iv) was evaluated. Further, perivascular and myocardial fibrosis, arterial intimal thickening were assessed by histology, and capillary density, nitrotyrosine and ROCK1/2 expressions were evaluated by immunohistochemical staining. RESULTS Diabetic rats had significantly elevated plasma glucose (P < 0.001 vs control), but did not differ in fibrotic scores, media to lumen ratio, capillary density or baseline visible vessel number or calibre. Responses to acetylcholine and sodium nitroprusside stimulation were similar between groups. However, in comparison to control rats the diabetic rats showed more segmental constrictions during blockade, which were not completely alleviated by acetylcholine, but were alleviated by fasudil. Further, second order vessel branches in diabetic rats were significantly more dilated relative to baseline (37% vs 12% increase, P < 0.05) after fasudil treatment compared to control rats, while visible vessel number increased in both groups. ROCK2 expression was borderline greater in diabetic rat hearts (P < 0.053). CONCLUSIONS We found that ahead of the reported decline in coronary endothelial vasodilator function in diabetic rats there was moderate elevation in ROCK expression, more widespread segmental constriction when nitric oxide and prostacyclin production were inhibited and notably, increased calibre in second and third order small arteries-arterioles following ROCK inhibition. Based on nitrotyrosine staining oxidative stress was not significantly elevated in early diabetic rats. We conclude that tonic ROCK mediated vasoconstriction contributes to coronary vasomotor tone in early diabetes.
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Affiliation(s)
- James T Pearson
- Department of Physiology, Monash University, Melbourne, Australia
- Monash Biomedical Imaging Facility, Melbourne, Australia
- Australian Synchrotron, Melbourne, Australia
| | - Mathew J Jenkins
- Department of Physiology, Monash University, Melbourne, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Melbourne, Australia
| | - Amanda J Edgley
- Department of Physiology, Monash University, Melbourne, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Melbourne, Australia
| | - Takashi Sonobe
- National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Mandar Joshi
- The Ritchie Centre, Monash Institute of Medical Research, Melbourne, Australia
| | - Mark T Waddingham
- Department of Physiology, Monash University, Melbourne, Australia
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Melbourne, Australia
| | - Yutaka Fujii
- National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Daryl O Schwenke
- Department of Physiology, Otago University, Dunedin, New Zealand
| | | | - Misa Yoshimoto
- National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Keiji Umetani
- Japan Synchrotron Radiation Research Institute, Harima, Japan
| | - Darren J Kelly
- Department of Medicine, St Vincent’s Hospital, University of Melbourne, Melbourne, Australia
| | - Mikiyasu Shirai
- National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
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Li DB, Yang GJ, Xu HW, Fu ZX, Wang SW, Hu SJ. Regulation on RhoA in Vascular Smooth Muscle Cells Under Inflammatory Stimulation Proposes a Novel Mechanism Mediating the Multiple-Beneficial Action of Acetylsalicylic Acid. Inflammation 2013; 36:1403-14. [DOI: 10.1007/s10753-013-9680-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Ozturk N, Yaras N, Ozmen A, Ozdemir S. Long-term administration of rosuvastatin prevents contractile and electrical remodelling of diabetic rat heart. J Bioenerg Biomembr 2013; 45:343-52. [PMID: 23640692 DOI: 10.1007/s10863-013-9514-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/19/2013] [Indexed: 01/09/2023]
Abstract
In recent years, many findings have been presented about the potential benefit of statin therapy on diabetes-induced cardiovascular complications. Cardioprotective effects of statins were suggested to be mediated at least in part through inhibition of small GTPases, particularly those of the Rho family. The present study was designed to examine whether rosuvastatin can improve electrical remodeling and contractile dysfunction in type 1 diabetic rat heart via modulation of RhoA pathway. Type 1 diabetes was induced by single dose injection of STZ (50 mg/kg). One week after injection rosuvastatin (10 mg/kg/day) and sham treatment was given for 5 weeks in the diabetic rats, as well as in control groups. Shortening and Ca²⁺ transients were recorded in myocytes loaded with Fura2-AM. Membrane currents and Ca²⁺ transients were measured synchronously via whole-cell patch clamping. In untreated diabetic rats, relaxation of shortening and decay of the matched Ca²⁺ transients were prolonged. Fractional shortening and Ca²⁺ transients were also decreased. Rosuvastatin treatment reversed those changes. I(CaL) density did not change in either group but rosuvastatin recovered the loss of sarcoplasmic reticulum Ca²⁺ and Na⁺/Ca²⁺ exchange as evidenced from amplitude and decay of caffeine-induced Ca²⁺ transients, peak INCX and calculated sarcoplasmic reticulum Ca²⁺ content. Diabetes-induced attenuation of I(to) and I(sus) was also reversed, whilst I(K1) was unchanged in diabetes and unaffected by treatment. Rosuvastatin prevented the diabetes-induced increase in RhoA expression. Plasma cholesterol and triglyceride levels were higher in diabetic rats, but rosuvastatin reduced only the latter. In conclusion, HMG-CoA reductase inhibitor rosuvastatin can prevent diabetes-induced electrical and functional remodeling of heart due to inhibition of RhoA signalling rather than reduction of cholesterol level.
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Affiliation(s)
- Nihal Ozturk
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya, Turkey
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25
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Mathew E, Barletta MA, Lau-Cam CA. The Effects of Taurine and Thiotaurine on Oxidative Stress in the Aorta and Heart of Diabetic Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 775:345-69. [DOI: 10.1007/978-1-4614-6130-2_28] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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26
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Possa SS, Charafeddine HT, Righetti RF, da Silva PA, Almeida-Reis R, Saraiva-Romanholo BM, Perini A, Prado CM, Leick-Maldonado EA, Martins MA, Tibério IDFLC. Rho-kinase inhibition attenuates airway responsiveness, inflammation, matrix remodeling, and oxidative stress activation induced by chronic inflammation. Am J Physiol Lung Cell Mol Physiol 2012; 303:L939-52. [PMID: 23002076 DOI: 10.1152/ajplung.00034.2012] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Several studies have demonstrated the importance of Rho-kinase in the modulation of smooth muscle contraction, airway hyperresponsiveness, and inflammation. However, the effects of repeated treatment with a specific inhibitor of this pathway have not been previously investigated. We evaluated the effects of repeated treatment with Y-27632, a highly selective Rho-kinase inhibitor, on airway hyperresponsiveness, oxidative stress activation, extracellular matrix remodeling, eosinophilic inflammation, and cytokine expression in an animal model of chronic airway inflammation. Guinea pigs were subjected to seven ovalbumin or saline exposures. The treatment with Y-27632 (1 mM) started at the fifth inhalation. Seventy-two hours after the seventh inhalation, the animals' pulmonary mechanics were evaluated, and exhaled nitric oxide (E(NO)) was collected. The lungs were removed, and histological analysis was performed using morphometry. Treatment with Y-27632 in sensitized animals reduced E(NO) concentrations, maximal responses of resistance, elastance of the respiratory system, eosinophil counts, collagen and elastic fiber contents, the numbers of cells positive for IL-2, IL-4, IL-5, IL-13, inducible nitric oxide synthase, matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, transforming growth factor-β, NF-κB, IFN-γ, and 8-iso-prostaglandin F2α contents compared with the untreated group (P < 0.05). We observed positive correlations among the functional responses and inflammation, remodeling, and oxidative stress pathway activation markers evaluated. In conclusion, Rho-kinase pathway activation contributes to the potentiation of the hyperresponsiveness, inflammation, the extracellular matrix remodeling process, and oxidative stress activation. These results suggest that Rho-kinase inhibitors represent potential pharmacological tools for the control of asthma.
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Affiliation(s)
- Samantha Souza Possa
- Department of Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
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Soliman H, Gador A, Lu YH, Lin G, Bankar G, MacLeod KM. Diabetes-induced increased oxidative stress in cardiomyocytes is sustained by a positive feedback loop involving Rho kinase and PKCβ2. Am J Physiol Heart Circ Physiol 2012; 303:H989-H1000. [PMID: 22865386 DOI: 10.1152/ajpheart.00416.2012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We previously reported that acute inhibition of the RhoA/Rho kinase (ROCK) pathway normalized contractile function of diabetic rat hearts, but the underlying mechanism is unclear. Protein kinase C (PKC) β(2) has been proposed to play a major role in diabetic cardiomyopathy at least in part by increasing oxidative stress. Further evidence suggests that PKC positively regulates RhoA expression through induction of inducible nitric oxide synthase (iNOS) in diabetes. However, in preliminary studies, we found that inhibition of ROCK itself reduced RhoA expression in diabetic hearts. We hypothesized that there is an interaction between RhoA/ROCK and PKCβ(2) in the form of a positive feedback loop that sustains their activation and the production of reactive oxygen species (ROS). This was investigated in cardiomyocytes isolated from diabetic and control rat hearts, incubated with or without cytochalasin D or inhibitors of ROCK, RhoA, PKCβ(2), or iNOS. Inhibition of RhoA and ROCK markedly attenuated the diabetes-induced increases in PKCβ(2) activity and iNOS and RhoA expression in diabetic cardiomyocytes, while having no effect in control cells. Inhibition of PKCβ(2) and iNOS also normalized RhoA expression and ROCK overactivation, whereas iNOS inhibition reversed the increase in PKCβ(2) activity. Each of these treatments also normalized the diabetes-induced increase in production of ROS. Actin cytoskeleton disruption attenuated the increased expression and/or activity of all of these targets in diabetic cardiomyocytes. These data suggest that, in the diabetic heart, the RhoA/ROCK pathway contributes to contractile dysfunction at least in part by sustaining PKCβ(2) activation and ROS production via a positive feedback loop that requires an intact cytoskeleton.
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Affiliation(s)
- Hesham Soliman
- Molecular and Cellular Pharmacology Research Group, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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Acetylsalicylic acid regulates overexpressed small GTPase RhoA in vascular smooth muscle cells through prevention of new synthesis and enhancement of protein degradation. Biosci Rep 2012; 32:153-60. [PMID: 21756248 DOI: 10.1042/bsr20110050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
RhoA has been shown to play a major role in vascular processes and acetylsalicylic acid (aspirin) is known to exert a cytoprotective effect via multiple mechanisms. In the present study, we aimed at investigating the effect of aspirin on RhoA expression under a stress state in rat VSMCs (vascular smooth muscle cells) and the underlying mechanisms. The expression of iNOS (inducible nitric oxide synthase) and iNOS activity as well as NO concentration was significantly promoted by LPS (lipopolysaccharide) accompanying the elevation of RhoA expression, which was blocked by the addition of the iNOS inhibitor L-NIL [L-N6-(1-iminoethyl)lysine dihydrochloride]. Aspirin (30 μM) significantly attenuated the elevation of RhoA, while indomethacin and salicylate had no similar effect. The sGC (soluble guanylate cyclase) inhibitor ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) showed the same effect as aspirin in down-regulating RhoA but was reversed by the addition of the cGMP analogue 8-Br-PET-cGMP (β-phenyl-1,N2-ethano-8-bromoguanosine 3',5'-cyclic monophosphorothioate). 8-Br-PET-cGMP solely enhanced the RhoA expression that was abrogated by preincubation with aspirin. Degradation analysis indicated that aspirin enhanced the protein degradation rate of RhoA and GDP-bound RhoA seemed to be more susceptible to aspirin-enhanced degradation compared with the GTP-bound form. Our results indicate that aspirin attenuates the LPS-induced overexpression of RhoA both by inhibiting new synthesis and accelerating protein degradation, which may help elucidate the multiple beneficial effects of aspirin.
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Gayard M, Guilluy C, Rousselle A, Viollet B, Henrion D, Pacaud P, Loirand G, Rolli-Derkinderen M. AMPK Alpha 1-Induced RhoA Phosphorylation Mediates Vasoprotective Effect of Estradiol. Arterioscler Thromb Vasc Biol 2011; 31:2634-42. [DOI: 10.1161/atvbaha.111.228304] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Objective—
Estradiol (E2) mediates numerous beneficial effects assigned to estrogens, but whereas mechanisms have been described at the endothelial level, direct effects on vascular smooth muscle cells (VSMC) are poorly documented. As evidence accumulates regarding the role of RhoA in vascular pathophysiology and the benefit of RhoA-Rho associated protein kinase (Rock) pathway inhibition, we analyzed if E2 could inhibit it in VSMC.
Methods and Results—
We show that in VSMC, E2 inhibits the RhoA-Rock pathway in a time- and concentration-dependent manner. The inhibition of RhoA-Rock pathway results from E2-induced phosphorylation of the Ser188 of RhoA. Using pharmacological, transfection, and in vitro phosphorylation experiments, we demonstrate that AMP-activated protein kinase subunit alpha 1 (AMPKα1) is activated by estrogen receptor stimulation and catalyzes RhoA phosphorylation induced by E2. Ex vivo, ovariectomy leads to an increase in the amplitude of phenylephrine- or serotonine-induced contractions of aortic rings in wild-type mice but not in AMPKα1-knock-out mice or E2-supplemented animals. These functional effects were correlated with a reduced level of RhoA phosphorylation in the aorta of ovariectomized female, male, and AMPKα1 knock-out mice.
Conclusion—
Our work thus defines AMPKα1 as (1) a new kinase for RhoA and (2) a new mediator of the vasoprotective effects of estrogen.
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Affiliation(s)
- Marion Gayard
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Christophe Guilluy
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Anthony Rousselle
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Benoit Viollet
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Daniel Henrion
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Pierre Pacaud
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Gervaise Loirand
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
| | - Malvyne Rolli-Derkinderen
- From the Institut National de la Santé et de la Recherche Médicale (INSERM) (M.G., C.G., A.R., P.P., G.L., M.R.D.), UMR915, Institut du Thorax, Nantes, France; Institut Cochin (B.V.), Université Paris Descartes, Centre National de la Recherche Scientifique (CNRS) (UMR 8104), Paris, France; INSERM (B.V.), U567, Paris, France; CNRS UMR 6214 (D.H.), Angers, France; Université de Nantes and CHU Nantes (P.P., G.L.), Nantes, France
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Okazaki T, Otani H, Shimazu T, Yoshioka K, Fujita M, Iwasaka T. Ascorbic acid and N-acetyl cysteine prevent uncoupling of nitric oxide synthase and increase tolerance to ischemia/reperfusion injury in diabetic rat heart. Free Radic Res 2011; 45:1173-83. [PMID: 21756052 DOI: 10.3109/10715762.2011.605361] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Oxidative stress may cause a loss of tetrahydrobiopterin (BH4), a co-factor of nitric oxide synthase (NOS), decrease the bioavailability of NO and aggravate ischemia/reperfusion (I/R) injury in diabetic heart. We hypothesized that ascorbic acid (AA) and N-acetyl cysteine (NAC) protect the diabetic heart from I/R injury by increasing BH4/dihydrobiopterin (BH2) ratio and inhibiting uncoupling of NOS. Diabetes mellitus was induced in rats by streptozotocin treatment, and the hearts were isolated and perfused. BH4 and BH4/BH2 ratio decreased in the diabetic heart associated with increased production of superoxide and nitrotyrosine (NT). Treatment with AA or NAC significantly increased BH4/BH2 ratio in the diabetic heart associated with decreased production of superoxide and NT and increased generation of nitrate plus nitrite (NOx). Pre-treatment with AA or NAC before 30 min ischemia followed by 120 min reperfusion improved left ventricular (LV) function and reduced infarct size in the diabetic but not non-diabetic hearts. The NOS inhibitor, L-NAME, inhibited the increase in the generation of superoxide, NT and NOx, but aggravated LV function and increased infarct size in the diabetic heart. L-NAME also abrogated the increase in NOx and improvement of LV function and the infarct size-limiting effect induced by AA or NAC in the diabetic heart. These results suggest that AA and NAC increase BH4/BH2 ratio and prevent NOS uncoupling in the diabetic heart. Resultant increase in the bioavailability of NO renders the diabetic heart toleratant to I/R injury.
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Affiliation(s)
- Toru Okazaki
- Second Department of Internal Medicine, Kansai Medical University, Moriguchi City, Japan
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Roe ND, Ren J. Akt2 knockout mitigates chronic iNOS inhibition-induced cardiomyocyte atrophy and contractile dysfunction despite persistent insulin resistance. Toxicol Lett 2011; 207:222-31. [PMID: 21964073 DOI: 10.1016/j.toxlet.2011.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Revised: 09/11/2011] [Accepted: 09/12/2011] [Indexed: 11/18/2022]
Abstract
Increased levels of inducible nitric oxide synthase (iNOS) during cardiac stress such as ischemia-reperfusion, sepsis and hypertension may display both beneficial and detrimental roles in cardiac contractile performance. However, the precise role of iNOS in the maintenance of cardiac contractile function remains elusive. This study was designed to determine the impact of chronic iNOS inhibition on cardiac contractile function and the underlying mechanism involved with a special focus on the NO downstream signaling molecule Akt. Male C57 or Akt2 knockout [Akt2(-/-)] mice were injected with the specific iNOS inhibitor 1400W (2 mg/kg/d) or saline for 7 days. Both 1400W and Akt2 knockout dampened glucose and insulin tolerance without additive effects. Treatment of 1400W decreased heart and liver weights as well as cardiomyocyte cross-sectional area in C57 but not Akt2 knockout mice. 1400W but not Akt2 knockout compromised cardiomyocyte mechanical properties including decreased peak shortening and maximal velocity of shortening/relengthening, prolonged relengthening duration, reduced intracellular Ca(2+) release and decay rate, the effects of which were ablated or attenuated by Akt2 knockout. Akt2 knockout but not 1400W increased the levels of intracellular Ca(2+) regulatory proteins including SERCA2a and phospholamban phosphorylation. 1400W reduced the level of anti-apoptotic protein Bcl-2, the effect of which was unaffected by Akt2 knockout. Neither 1400W nor Akt2 knockout significantly affected ER stress, autophagy, the post-insulin receptor signaling Akt, GSK3β and AMPK, as well as the stress signaling IκB, JNK, ERK and p38 with the exception of elevated IκB phosphorylation with jointed effect of 1400W and Akt2 knockout. Taken together, these data indicated that an essential role of iNOS in the maintenance of cardiac morphology and function possibly through an Akt2-dependent mechanism.
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Affiliation(s)
- Nathan D Roe
- Division of Pharmaceutical Sciences & Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA
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Thuet KM, Bowles EA, Ellsworth ML, Sprague RS, Stephenson AH. The Rho kinase inhibitor Y-27632 increases erythrocyte deformability and low oxygen tension-induced ATP release. Am J Physiol Heart Circ Physiol 2011; 301:H1891-6. [PMID: 21890695 DOI: 10.1152/ajpheart.00603.2011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Low oxygen (O(2)) tension and mechanical deformation are stimuli for ATP release from erythrocytes. It has been shown previously that rabbit erythrocytes made less deformable with diamide, a thiol cross-linking agent, release less ATP in response to low O(2) tension, suggesting a link between these two stimuli. In nonerythroid cells, activation of the Rho/Rho kinase signaling pathway has been reported to decrease cell deformability by altering Rho kinase-dependent cytoskeleton-protein interactions. We investigated the hypothesis that the Rho kinase inhibitor Y-27632 would increase erythrocyte deformability and thereby increase low O(2) tension-induced ATP release from erythrocytes. Here we show that Y-27632 (1 μM) increases erythrocyte deformability (5%) and increases low O(2) tension-induced ATP release (203%) from healthy human erythrocytes. In addition, we found that, when erythrocytes were made less deformable by incubation with diamide (100 μM), Y-27632 restored both deformability and low O(2) tension-induced ATP release to levels similar to those measured in the absence of diamide. These findings suggest that the Rho kinase inhibitor Y-27632 is able to reverse the diamide-induced decrease in erythrocyte deformability and rescue low O(2) tension-induced ATP release. These results further support a link between erythrocyte deformability and ATP release in response to low O(2) tension.
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Affiliation(s)
- K M Thuet
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, St. Louis, MO 63104, USA.
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Zhou H, Li YJ, Wang M, Zhang LH, Guo BY, Zhao ZS, Meng FL, Deng YG, Wang RY. Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes. Acta Pharmacol Sin 2011; 32:999-1008. [PMID: 21743486 DOI: 10.1038/aps.2011.54] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate whether activation of RhoA/Rho kinase (ROCK) is involved in myocardial fibrosis in diabetic hearts. METHODS A rat model of type 2 diabetes was established using high fat diet combined with streptozotocin (30 mg/kg, ip). Animals were randomly divided into 3 groups: control rats, untreated diabetic rats that received vehicle and treated diabetic rats that received Rho-kinase inhibitor fasudil hydrochloride hydrate (10 mg·kg(-1)·d(-1), ip, for 14 weeks). Cardiac contractile function was evaluated in vivo. The morphological features of cardiac fibrosis were observed using immunohistochemistry and TEM. The mRNA expression of JNK, TGFβ1, type-I, and type-III procollagen was assessed with RT-PCR. The phosphorylation of MYPT1, JNK and Smad2/3, as well as the protein levels of TGFβ1 and c-Jun, were evaluated using Western blotting. RESULTS In untreated diabetic rats, myocardial fibrosis was developed and the heart contractility was significantly reduced as compared to the control rats. In the hearts of untreated diabetic rats, the mRNA expression level and activity of JNK were upregulated; the expression of TGFβ1 and phosphorylation of Smad2/3 were increased. In the hearts of treated diabetic rat, activation of JNK and TGFβ/Smad was significantly decreased, myocardial fibrosis was reduced, and cardiac contractile function improved. CONCLUSION The data suggest that fasudil hydrochloride hydrate ameliorates myocardial fibrosis in rats with type 2 diabetes at least in part through inhibiting the JNK and TGFβ/Smad pathways. Inhibition of RhoA/ROCK may be a novel therapeutic target for prevention of diabetic cardiomyopathy.
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Jo H, Otani H, Jo F, Shimazu T, Okazaki T, Yoshioka K, Fujita M, Kosaki A, Iwasaka T. Inhibition of nitric oxide synthase uncoupling by sepiapterin improves left ventricular function in streptozotocin-induced diabetic mice. Clin Exp Pharmacol Physiol 2011; 38:485-93. [PMID: 21554376 DOI: 10.1111/j.1440-1681.2011.05535.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. Uncoupling of nitric oxide synthase (NOS) has been implicated in the pathogenesis of left ventricular (LV) dysfunction in diabetes mellitus. In the present study, we investigated the role of NOS uncoupling in oxidative/nitrosative stress and LV dysfunction in the diabetic mouse heart. 2. Diabetes was induced in wild-type (WT), endothelial (e) NOS knockout (eNOS(-/-)), inducible (i) NOS knockout (iNOS(-/-)) and neuronal (n) NOS knockout (nNOS(-/-)) mice by streptozotocin (STZ) treatment. 3. In the diabetic heart, iNOS, but not eNOS or nNOS, expression was increased. Levels of malondialdehyde (MDA), 4-hydroxy-noneal (HNE) and nitrotyrosine (NT), as markers of oxidative/nitrosative stress, were increased in the diabetic mouse heart, but the increase in oxidative/nitrosative stress was significantly repressed in the iNOS(-/-) diabetic mouse heart. Levels of nitrite and nitrate (NO(x)), as an index of nitric oxide, bioavailability were significantly decreased in the iNOS(-/-) diabetic mouse heart. 4. Oral administration of sepiapterin (10 mg/kg per day), a precursor of tetrahydrobiopterin (BH(4)), significantly increased BH(4) and the BH(4)/BH(2) ratio in diabetic mouse heart. Similarly, sepiapterin inhibited the formation of HNE, MDA and NT in diabetic hearts from all three genotypes, but the increase in NO(x) following sepiapterin treatment was significantly attenuated in the iNOS(-/-) diabetic mouse heart. Percentage fractional shortening (FS), evaluated by echocardiography, decreased significantly in all genotypes of diabetic mice. Sepiapterin significantly increased percentage FS in diabetic mice, except in iNOS(-/-) mice. 5. These results suggest that sepiapterin inhibits uncoupling of NOS and improves LV function presumably by increasing iNOS-derived nitric oxide in the diabetic heart.
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Affiliation(s)
- Hiromi Jo
- Second Department of Internal Medicine, Kansai Medical University, Moriguchi, Japan
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ROCK induced inflammation of the microcirculation during endotoxemia mediated by nitric oxide synthase. Microvasc Res 2011; 81:281-8. [DOI: 10.1016/j.mvr.2011.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 01/29/2011] [Accepted: 02/17/2011] [Indexed: 12/20/2022]
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Abstract
This review addresses the roles of Rho/Rho-kinase (ROCK) pathway in the pathogenesis of diabetes complications. Diabetes can cause many serious complications and can result in physical disability or even increased mortality. However, there are not many effective ways to treat these complications. The small guanosine-5'-triphosphate-binding protein Rho and its downstream target Rho-kinase mediate important cellular functions, such as cell morphology, motility, secretion, proliferation, and gene expression. Recently, the Rho/Rho-kinase pathway has attracted a great deal of attention in diabetes-related research. These studies have provided evidence that the activity and gene expression of Rho-kinase are upregulated in some tissues in animal models of type 1 or type 2 diabetes and in cell lines cultured with high concentrations of glucose. Inhibitors of Rho-kinase could prevent or ameliorate the pathological changes in diabetic complications. The inhibitory effects of statins on the Rho/Rho-kinase signalling pathway may also play a role in the prevention of diabetic complications. However, the precise molecular mechanism by which the Rho/Roh-kinase pathway participates in the development or progression of diabetic complications has not been extensively investigated. This article evaluates the relationship between Rho/Roh-kinase activation and diabetic complications, as well as the roles of Roh-kinase inhibitors and statins in the complications of diabetes, with the objective of providing a novel target for the treatment of long-term diabetic complications.
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Affiliation(s)
- Hong Zhou
- Department of Endocrinology, The Second Hospital of He Bei Medical University, Shijiazhuang, China
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Heo J. Redox control of GTPases: from molecular mechanisms to functional significance in health and disease. Antioxid Redox Signal 2011; 14:689-724. [PMID: 20649471 DOI: 10.1089/ars.2009.2984] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Small GTPases, including the proto-oncoprotein Ras and Rho GTPases, are involved in various cellular signaling events. Some of these small GTPases are redox sensitive, including Ras, Rho, Ran, Dexras1, and Rhes GTPases. Thus, the redox-mediated regulation of these GTPases often determines the course of their cellular signaling cascades. This article takes into consideration the application of Marcus theory to potential redox-based molecular mechanisms in the regulation of these redox-sensitive GTPases and the relevance of such mechanisms to a specific redox-sensitive motif. The discussion also takes into account various diseases, including cancers, heart, and neuronal disorders, that are often linked with the dysregulation of the redox signaling cascades associated with these redox-sensitive GTPases.
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Affiliation(s)
- Jongyun Heo
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA.
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Abstract
Normal urinary bladder function is based on the proper contraction and relaxation of smooth muscle (SM), which constitutes the majority of the bladder wall. The contraction and relaxation of all SM involves a phosphorylation-dephosphorylation pathway involving the enzymes smooth muscle myosin light chain kinase (SMMLCK) and smooth muscle myosin light chain phosphatase (SMMLCP), respectively. Although originally thought to function just as a passive opposition to SMMLCK-driven SM contraction, it is now clear that SMMLCP activity is under an extremely complex molecular regulation via which SMMLCP inhibition can induce "calcium sensitization." This review provides a thorough summary of the literature regarding the molecular regulation of the SMMLCP with a focus on one of its major inhibitory pathways that is RhoA/Rho-kinase (ROK) including its activation pathways, effector molecules, and its roles in various pathological conditions associated with bladder dysfunction. Newly emerging roles of ROK outside of SM contractility are also discussed. It is concluded that the RhoA/ROK pathway is critical for the maintenance of basal SM tone of the urinary bladder and serves as a common final pathway of various contractile stimuli in rabbits, rats, mice, and pigs as well as humans. In addition, this pathway is upregulated in response to a number of pathological conditions associated with bladder SM dysfunction. Similarly, RhoA/Rho-kinase signaling is essential for normal ureteral function and development and is upregulated in response to ureteral outlet obstruction. In addition to its critical role in bladder SM function, a role of ROK in the urothelium is also beginning to emerge as well as roles for ROK in bladder infection and invasion and metastasis of bladder cancer.
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Moreno-López B, Sunico CR, González-Forero D. NO orchestrates the loss of synaptic boutons from adult "sick" motoneurons: modeling a molecular mechanism. Mol Neurobiol 2010; 43:41-66. [PMID: 21190141 DOI: 10.1007/s12035-010-8159-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 12/02/2010] [Indexed: 12/14/2022]
Abstract
Synapse elimination is the main factor responsible for the cognitive decline accompanying many of the neuropathological conditions affecting humans. Synaptic stripping of motoneurons is also a common hallmark of several motor pathologies. Therefore, knowledge of the molecular basis underlying this plastic process is of central interest for the development of new therapeutic tools. Recent advances from our group highlight the role of nitric oxide (NO) as a key molecule triggering synapse loss in two models of motor pathologies. De novo expression of the neuronal isoform of NO synthase (nNOS) in motoneurons commonly occurs in response to the physical injury of a motor nerve and in the course of amyotrophic lateral sclerosis. In both conditions, this event precedes synaptic withdrawal from motoneurons. Strikingly, nNOS-synthesized NO is "necessary" and "sufficient" to induce synaptic detachment from motoneurons. The mechanism involves a paracrine/retrograde action of NO on pre-synaptic structures, initiating a downstream signaling cascade that includes sequential activation of (1) soluble guanylyl cyclase, (2) cyclic guanosine monophosphate-dependent protein kinase, and (3) RhoA/Rho kinase (ROCK) signaling. Finally, ROCK activation promotes phosphorylation of regulatory myosin light chain, which leads to myosin activation and actomyosin contraction. This latter event presumably contributes to the contractile force to produce ending axon retraction. Several findings support that this mechanism may operate in the most prevalent neurodegenerative diseases.
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Affiliation(s)
- Bernardo Moreno-López
- Grupo de NeuroDegeneración y NeuroReparación (GRUNEDERE), Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Plaza Falla, 9, 11003 Cádiz, Spain.
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Moreno-López B. Local isoform-specific NOS inhibition: a promising approach to promote motor function recovery after nerve injury. J Neurosci Res 2010; 88:1846-57. [PMID: 20143424 DOI: 10.1002/jnr.22353] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Physical injury to a nerve is the most frequent cause of acquired peripheral neuropathy, which is responsible for loss of motor, sensory and/or autonomic functions. Injured axons in the peripheral nervous system maintain the capacity to regenerate in adult mammals. However, after nerve transection, stumps of damaged nerves must be surgically joined to guide regenerating axons into the distal nerve stump. Even so, severe functional limitations persist after restorative surgery. Therefore, the identification of molecules that regulate degenerative and regenerative processes is indispensable in developing therapeutic tools to accelerate and improve functional recovery. Here, I consider the role of nitric oxide (NO) synthesized by the three major isoforms of NO synthases (NOS) in motor neuropathy. Neuronal NOS (nNOS) seems to be the primary source of NO that is detrimental to the survival of injured motoneurons. Endothelial NOS (eNOS) appears to be the major source of NO that interferes with axonal regrowth, at least soon after injury. Finally, NO derived from inducible NOS (iNOS) or nNOS is critical to the process of lipid breakdown for Wallerian degeneration and thereby benefits axonal regrowth. Specific inhibitors of these isoforms can be used to protect injured neurons from degeneration and promote axonal regeneration. A cautious proposal for the treatment of acquired motor neuropathy using therapeutic tools that locally interfere with eNOS/nNOS activities seems to merit consideration.
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Thyroid hormone can favorably remodel the diabetic myocardium after acute myocardial infarction. Mol Cell Biochem 2010; 345:161-9. [DOI: 10.1007/s11010-010-0569-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022]
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Nitric oxide induces pathological synapse loss by a protein kinase G-, Rho kinase-dependent mechanism preceded by myosin light chain phosphorylation. J Neurosci 2010; 30:973-84. [PMID: 20089906 DOI: 10.1523/jneurosci.3911-09.2010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The molecular signaling that underpins synapse loss in neuropathological conditions remains unknown. Concomitant upregulation of the neuronal nitric oxide (NO) synthase (nNOS) in neurodegenerative processes places NO at the center of attention. We found that de novo nNOS expression was sufficient to induce synapse loss from motoneurons at adult and neonatal stages. In brainstem slices obtained from neonatal animals, this effect required prolonged activation of the soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway and RhoA/Rho kinase (ROCK) signaling. Synapse elimination involved paracrine/retrograde action of NO. Furthermore, before bouton detachment, NO increased synapse myosin light chain phosphorylation (p-MLC), which is known to trigger actomyosin contraction and neurite retraction. NO-induced MLC phosphorylation was dependent on cGMP/PKG-ROCK signaling. In adulthood, motor nerve injury induced NO/cGMP-dependent synaptic stripping, strongly affecting ROCK-expressing synapses, and increased the percentage of p-MLC-expressing inputs before synapse destabilization. We propose that this molecular cascade could trigger synapse loss underlying early cognitive/motor deficits in several neuropathological states.
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Nagareddy PR, Soliman H, Lin G, Rajput PS, Kumar U, McNeill JH, MacLeod KM. Selective inhibition of protein kinase C beta(2) attenuates inducible nitric oxide synthase-mediated cardiovascular abnormalities in streptozotocin-induced diabetic rats. Diabetes 2009; 58:2355-64. [PMID: 19587355 PMCID: PMC2750218 DOI: 10.2337/db09-0432] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Impaired cardiovascular function in diabetes is partially attributed to pathological overexpression of inducible nitric oxide synthase (iNOS) in cardiovascular tissues. We examined whether the hyperglycemia-induced increased expression of iNOS is protein kinase C-beta(2) (PKCbeta(2)) dependent and whether selective inhibition of PKCbeta reduces iNOS expression and corrects abnormal hemodynamic function in streptozotocin (STZ)-induced diabetic rats. RESEARCH DESIGN AND METHODS Cardiomyocytes and aortic vascular smooth muscle cells (VSMC) from nondiabetic rats were cultured in low (5.5 mmol/l) or high (25 mmol/l) glucose or mannitol (19.5 mmol/l mannitol + 5.5 mmol/l glucose) conditions in the presence of a selective PKCbeta inhibitor, LY333531 (20 nmol/l). Further, the in vivo effects of PKCbeta inhibition on iNOS-mediated cardiovascular abnormalities were tested in STZ-induced diabetic rats. RESULTS Exposure of cardiomyocytes to high glucose activated PKCbeta(2) and increased iNOS expression that was prevented by LY333531. Similarly, treatment of VSMC with LY333531 prevented high glucose-induced activation of nuclear factor kappaB, extracellular signal-related kinase, and iNOS overexpression. Suppression of PKCbeta(2) expression by small interference RNA decreased high-glucose-induced nuclear factor kappaB and extracellular signal-related kinase activation and iNOS expression in VSMC. Administration of LY333531 (1 mg/kg/day) decreased iNOS expression and formation of peroxynitrite in the heart and superior mesenteric arteries and corrected the cardiovascular abnormalities in STZ-induced diabetic rats, an action that was also observed with a selective iNOS inhibitor, L-NIL. CONCLUSIONS Collectively, these results suggest that inhibition of PKCbeta(2) may be a useful approach for correcting abnormal hemodynamics in diabetes by preventing iNOS mediated nitrosative stress.
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Affiliation(s)
- Prabhakara Reddy Nagareddy
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Hesham Soliman
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Guorong Lin
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Padmesh S. Rajput
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Ujendra Kumar
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - John H. McNeill
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathleen M. MacLeod
- From the Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author: Kathleen M. MacLeod,
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Nagareddy PR, McNeill JH, MacLeod KM. Chronic inhibition of inducible nitric oxide synthase ameliorates cardiovascular abnormalities in streptozotocin diabetic rats. Eur J Pharmacol 2009; 611:53-9. [PMID: 19344709 DOI: 10.1016/j.ejphar.2009.03.061] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 03/11/2009] [Accepted: 03/23/2009] [Indexed: 02/05/2023]
Abstract
Previous studies from our lab have demonstrated cardiovascular abnormalities such as depressed mean arterial blood pressure and heart rate, endothelial dysfunction and attenuated pressor responses to vasoactive agents in streptozotocin diabetic rats. We investigated whether these abnormalities are due to diabetes-associated chronic activation of inducible nitric oxide synthase (iNOS). Control and streptozotocin (60 mg/kg, iv) diabetic rats were treated with either vehicle or N6-(1-Iminoethyl)-L-lysine dihydrochloride (L-NIL, 3 mg/kg/day, p.o), a specific inhibitor of iNOS for 8 weeks. At the end of treatment, the mean arterial blood pressure and heart rate were measured in freely moving conscious rats. Further, pressor responses to bolus doses of methoxamine were determined. Endothelial nitric oxide synthase (eNOS) and iNOS expression as well as nitrotyrosine (NT) levels were assessed in the heart and superior mesenteric arteries by western blot and immunohistochemistry. Untreated diabetic rats showed depressed mean arterial blood pressure and heart rate and exhibited vascular hyporeactivity that were significantly improved by treatment with L-NIL. Further, decreased eNOS expression and increased iNOS expression and activity were associated with increased NT levels in the heart and superior mesenteric arteries of untreated diabetic rats. L-NIL treatment of diabetic rats normalized the expression of eNOS and NT levels without any effect on iNOS expression in the heart and superior mesenteric arteries. The results of our study suggest that induction of iNOS in cardiovascular tissues contributes significantly to the depressed mean arterial blood pressure, heart rate and pressor responses to vasoactive agents. Chronic inhibition of iNOS in diabetes may prove beneficial in the treatment of cardiovascular abnormalities.
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