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Li C, Deng S, Liu W, Zhou D, Huang Y, Liang CQ, Hao L, Zhang G, Su S, Xu X, Yang R, Li J, Huang X. α-Glucosidase inhibitory and anti-inflammatory activities of dammarane triterpenoids from the leaves of Cyclocarya paliurus. Bioorg Chem 2021; 111:104847. [PMID: 33798849 DOI: 10.1016/j.bioorg.2021.104847] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 01/14/2021] [Accepted: 03/18/2021] [Indexed: 12/23/2022]
Abstract
Diabetes mellitus is caused by chronic inflammation and affects millions of people worldwide. Cyclocarya paliurus leaves have been widely used in traditional folk tea as a remedy for diabetes, but the antidiabetic constituents remain to be further studied. The α-glucosidase inhibitory and anti-inflammatory activities were examined to evaluate their effects on diabetes mellitus, and bioassay-guided separation of C. paliurus leaves led to the identification of twenty dammarane saponins, including eleven new dammarane saponins (1-11). The structures of the isolates were elucidated by spectroscopic methods. Bioactivity assay results showed that compounds 1 and 2 strongly inhibited α-glucosidase activity, with IC50 values ranging from 257.74 μM, 282.23 μM, and strongly inhibited the release of NO, with IC50 values of 9.10 μM, 9.02 μM. Moreover, compound 2 significantly downregulated the mRNA expression of iNOS, COX-2, IL-1β, NF-κB, IL-6 and TNF-α in LPS-mediated RAW 264.7 cells and markedly suppressed the protein expression of iNOS, NF-κB/p65, and COX-2. Dammarane glucoside 2 exhibited the strongest α-glucosidase inhibitory and anti-inflammatory activities. In addition, the structure-activity relationships (SARs) of the dammarane saponins were investigated. In summary, C. paliurus leaves showed marked α-glucosidase inhibitory and anti-inflammatory activities, and dammarane saponins are responsible for regulating α-glucosidase, inflammatory mediators, and mRNA and the protein expression of proinflammatory cytokines, which could be meaningful for discovering new antidiabetic agents.
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Affiliation(s)
- Chenguo Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Shengping Deng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Wei Liu
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Dexiong Zhou
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Yan Huang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Cheng-Qin Liang
- College of Pharmacy, Guilin Medical University, Guilin 541004, China
| | - Lili Hao
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Gaorong Zhang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Shanshan Su
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Xia Xu
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Ruiyun Yang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China
| | - Jun Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China; Institute for Sustainable Development and Innovation, Guangxi Normal University, Guilin 541004, China.
| | - Xishan Huang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, China.
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Lu CH, Ou HC, Day CH, Chen HI, Pai PY, Lee CY, Chen RJ, Chang RL, PadmaViswanadha V, Hsieh DJY, Huang CY. Deep sea minerals ameliorate diabetic-induced inflammation via inhibition of TNFα signaling pathways. ENVIRONMENTAL TOXICOLOGY 2020; 35:468-477. [PMID: 31794124 DOI: 10.1002/tox.22882] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/25/2019] [Accepted: 11/03/2019] [Indexed: 06/10/2023]
Abstract
It has been well-documented that the consumption of deep sea water (DSW) has beneficial effects on myocardial hypertrophy and cardiac apoptosis induced by hypercholesterolemia. However, the molecular mechanisms for the anti-inflammatory effects of DSW on diabetic cardiomyopathy are still largely unclear. The main purpose of this present study was to test the hypothesis that DSW exerts anti-inflammatory effects through the suppression of the TNF-α-mediated signaling pathways. IP injection of streptozotocin (STZ) at the dose of 65 mg/kg was used to establish a diabetes rat model. DSW mineral extracts that diluted in desalinated water were prepared in three different dosages and administered to the rats through gavages for 4 weeks. These dosages are DSW-1X (equivalent to 37 mg Mg2+ /kg/day), 2X (equivalent to 74 mg Mg2+ /kg/day) and 3X (equivalent to 111 mg Mg2+ mg/kg/day). Immunofluorescence staining and Western blot showed that the protein expression level of TNF-α was markedly higher in the STZ-induced diabetic rat hearts than in the control group. Consequently, the phosphorylation levels of the TNF-α-modulated downstream signaling molecules and P38 mitogen-activated protein kinases (MAPKs) were notably elevated in heart tissues of STZ-induced diabetes. These higher phosphorylation levels subsequently upregulated NF-κB-modulated inflammatory mediators, such as cyclooxygenase (COX)-II and inducible nitric oxide synthase (iNOS). However, treatment with DSW as well as MgSO4 , the main mineral in DSW, significantly reversed all the alterations. These findings suggest that DSW has potential as a therapeutic agent for preventing diabetes-related cardiovascular diseases.
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Affiliation(s)
- Chieh-Hsiang Lu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
| | - Hsiu-Chung Ou
- Department of Physical Therapy, College of Medical and Health Science, Asia University, Taichung, Taiwan
| | | | - Hsiu-I Chen
- Department of Physical Therapy, Hungkuang University, Taichung, Taiwan
| | - Pei-Ying Pai
- School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
- Division of Cardiovascular Medicine, Department of Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Cheng-Yu Lee
- Department of Cardiology, Taipei City Hospital, Zhongxiao Branch, Taipei, Taiwan
| | - Ray-Jade Chen
- Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ruey-Lin Chang
- School of Post-Baccalaureate Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan
| | | | - Dennis Jine-Yuan Hsieh
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chih-Yang Huang
- Graduate Institute of Biomedicine, China Medical University and Hospital, Taichung, Taiwan
- Department of Biotechnology, Asia University, Taichung, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
- Cardiovascular and Mitochondrial Related Diseases Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
- Center of General Education, Buddhist Tzu Chi Medical Foundation, Tzu Chi University of Science and Technology, Hualien, Taiwan
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Korkmaz-Icöz S, Li S, Loganathan S, Radovits T, Ruppert M, Brlecic P, Sayour AA, Veres G, Fleming T, Brune M, Most P, Karck M, Szabó G. Impairment of the Akt pathway in transplanted Type 1 diabetic hearts is associated with post-transplant graft injury. Interact Cardiovasc Thorac Surg 2019; 27:884-894. [PMID: 29912386 DOI: 10.1093/icvts/ivy188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 05/13/2018] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES The use of 'marginal' hearts, such as from donors with diabetes mellitus (DM), could offer an opportunity to expand the donor pool in cardiac transplantation. Previous studies have shown that the phosphatidylinositol-3-kinase (PI3K)/Akt pathway is altered after ischaemia/reperfusion injury in the diabetic myocardium. We hypothesized that DM-induced cardiac dysfunction in donors is further impaired after heart transplantation and that PI3K/Akt-pathway alterations may be one of the underlying pathomechanisms. METHODS In the donor rats, DM was induced with a single dose of streptozotocin. Non-diabetic rats only received citrate buffer. After 8 weeks, the donor left ventricular (LV) cardiac function was measured. Then, the hearts were heterotopically transplanted into non-diabetic recipients. We evaluated LV graft function 1.5 h after transplantation via a Millar catheter system at different LV volumes. Histological analyses were performed, and the expression of 84 genes involved in PI3K/Akt signalling was profiled. RESULTS DM was associated with significantly decreased LV contractility and impaired relaxation. After transplantation, in the DM group, the grafts' systolic function (LV systolic pressure 112 ± 31 vs 155 ± 60 mmHg; dP/dtmax 2676 ± 896 vs 3584 ± 1779 mmHg/s, P < 0.05) and diastolic function (dP/dtmin 924 ± 205 vs 1748 ± 512 mmHg/s, P < 0.05) were significantly reduced at an intraventricular volume of 170 µl. The expression of 10 genes involved in PI3K/Akt signalling, as well as the phosphorylated Akt/total Akt protein expression ratio, were significantly down-regulated in the diabetic heart after transplantation. CONCLUSIONS DM-induced cardiac dysfunction is further impaired after transplantation. Targeting the PI3K/Akt pathway may result in a functional amelioration of the a priori-diseased myocardia, which could increase the number of potential cardiac donors.
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Affiliation(s)
- Sevil Korkmaz-Icöz
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Shiliang Li
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Tamás Radovits
- Heart and Vascular Center, Department of Cardiology, Semmelweis University, Budapest, Hungary
| | - Mihály Ruppert
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Paige Brlecic
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Alex Ali Sayour
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Gábor Veres
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Fleming
- Department of Medicine I and Clinical Chemistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Maik Brune
- Department of Medicine I and Clinical Chemistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Patrick Most
- Department of Internal Medicine III, Molecular and Translational Cardiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Gábor Szabó
- Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany
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Ge Q, Zhao L, Ren XM, Ye P, Hu ZY. LCZ696, an angiotensin receptor-neprilysin inhibitor, ameliorates diabetic cardiomyopathy by inhibiting inflammation, oxidative stress and apoptosis. Exp Biol Med (Maywood) 2019; 244:1028-1039. [PMID: 31262190 DOI: 10.1177/1535370219861283] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Diabetic cardiomyopathy, which refers to the destruction of the structure and function of the heart, is the primary cause of heart failure due to diabetes. LCZ696 is the first angiotensin receptor-neprilysin inhibitor (ARNi) to be used clinically. Our study investigated the role played by LCZ696 during diabetic cardiomyopathy and explored the potential mechanisms underlying these effects. Diabetes was induced by injecting streptozotocin intraperitoneally into mice, and the mice were then divided randomly into two groups: one group was treated with LCZ696 (60 mg/kg/d) for 16 weeks, and the other received no treatment. The H9C2 cardiomyoblast cell line was treated with LCZ696 under high-glucose (HG) conditions. The levels of apoptotic (Bax, Bcl-2 and cleaved caspase-3) and pro-inflammatory factors [nuclear factor (NF)-κB, c-Jun N-terminal kinase (JNK) and p38 mitogen-activated kinase (MAPK)] were assessed in heart tissues from diabetic and normal mice and in H9C2 cells. The heart tissue structures and cardiac functions of diabetic mice were compared with those of normal mice, using histological and echocardiographic analyses. The results showed that LCZ696 inhibits the nuclear transfer of NF-κB and JNK/p38MAPK phosphorylation, and mitigates inflammation and apoptosis in diabetic mice and H9C2 cardiomyocytes under HG conditions. The histological and echocardiographic data showed that compared with untreated diabetic mice, diabetic mice treated with LCZ696 exhibited improved ventricular remodeling and cardiac function. LCZ696 also ameliorated oxidative stress in both vivo and vitro. In conclusion, LCZ696 improved diabetic cardiomyopathy by reducing cardiac inflammation, oxidative stress, and apoptosis. Impact statement Diabetic cardiomyopathy (DCM) is an important cause of heart failure in patients with diabetes, resulting in increased morbidity and mortality. LCZ696, which was studied here, is a novel drug for the treatment of heart failure. The latest research reports that LCZ696 is more effective for preventing heart failure than valsartan alone. However, little research has been performed examining the effects of LCZ696 on DCM. This study was designed to examine the role played by LCZ696 during DCM and the potential mechanisms underlying these effects, which may provide the basis for a new therapeutic strategy for DCM.
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Affiliation(s)
- Qing Ge
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
| | - Li Zhao
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
| | - Xiao-Min Ren
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
| | - Peng Ye
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
| | - Zuo-Ying Hu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China
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Li B, Yang ZB, Lei SS, Su J, Jin ZW, Chen SH, Lv GY. Combined Antihypertensive Effect of Paeoniflorin Enriched Extract and Metoprolol in Spontaneously Hypertensive Rats. Pharmacogn Mag 2018; 14:44-52. [PMID: 29576700 PMCID: PMC5858241 DOI: 10.4103/pm.pm_483_16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 11/17/2016] [Indexed: 02/06/2023] Open
Abstract
Background: Hypertension is a great global health challenge and it mostly requires drug combination therapy with the various advantages. Metoprolol (MP) and paeoniflorin are both commonly used for the treatment of hypertension. However, whether they exert synergistic effects on antihypertension or not remains unclear, especially on vascular endothelial function. Objective: The purpose of the study is to investigate the advantages of the combined antihypertensive effects of paeoniflorin enriched extract from Radix Paeoniae Alba (RE) and MP in spontaneously hypertensive rats (SHR). Materials and Methods: SHR divided into six groups (n = 8 each group), animals in each group were administrated orally with distilled water, MP (6 and 20 mg/kg), RE (30 and 90 mg/kg), and MP (6 mg/kg) combined with RE (30 mg/kg) (MP + RE), respectively, daily for 6 weeks. Blood pressure (BP) and microcirculation were assessed. The organ bath experiment and hematoxylin and eosin staining were, respectively, performed for the functional and pathological vascular function analysis. Immunohistochemistry was applied to detect endothelial nitric oxide synthase (eNOS) expression in aorta, heart, and kidney. Further, high-performance liquid chromatography was employed to quantitatively determine paeoniflorin in RE and MP + RE sample solvent, as well as in plasma of Sprague-Dawley rats (SD) after single-dose administration of them. Results: The results showed that MP + RE significantly reduced BP, increased microcirculation, improved vascular function and pathological changes, and upregulated eNOS expression. MP was also found to increase the blood concentration of paeoniflorin in SD. Conclusion: The combination of RE and MP could be used for the treatment of hypertension and could improve microcirculation, upregulate eNOS expression, and mitigate endothelial dysfunction in SHR. SUMMARY Paeoniflorin enriched extract from Radix Paeoniae Alba and metoprolol exert synergistic antihypertensive effects.
Abbreviations used: RE: Paeoniflorin enriched extract from Radix Paeoniae Alba, MP: Metoprolol, MP + RE: MP combined with RE, NC: Normal control, MC: Model control, SHR: Spontaneously hypertensive rats, SD: Sprague-Dawley rats, H and E: Hematoxylin and eosin, BP: Blood pressure, SBP: Systolic blood pressure, DBP: Diastolic blood pressure, MBP: Mean arterial blood pressure, NA: Norepinephrine, ACh: Acetylcholine, SNP: Nitroprusside, NO: Nitric oxide, eNOS: Endothelial nitric oxide synthase, RPA: Radices Paeoniae Alba, IHC: Immunohistochemistry, Cmax: Peak concentration, Tmax: The time to reach Cmax, t½: Half-life, AUC0-t: Area under the curve of 0-t time; MRT0-t: Mean residence of 0-t time; CL: Clearance rate.
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Affiliation(s)
- Bo Li
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, P. R China.,College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
| | - Zheng-Biao Yang
- College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
| | - Shan-Sha Lei
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, P. R China.,College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
| | - Jie Su
- College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
| | - Ze-Wu Jin
- College of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang, P. R China
| | - Su-Hong Chen
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, P. R China.,College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China.,College of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, Zhejiang, P. R China
| | - Gui-Yuan Lv
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, P. R China.,College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, P. R China
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Simões FV, de Batista PR, Botelho T, Ribeiro-Júnior RF, Padilha AS, Vassallo DV. Treatment with high dose of atorvastatin reduces vascular injury in diabetic rats. Pharmacol Rep 2016; 68:865-73. [PMID: 27351941 DOI: 10.1016/j.pharep.2016.04.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Previous reports showed conflicting results regarding the treatment effects of statin on Diabetes mellitus (DM). We investigated how treatment with high dose of atorvastatin affects the impaired vascular function in diabetic rats. METHODS Atorvastatin (80mg/kg/day, oral gavage, 4 weeks) or its vehicle was administered to male control or streptozotocin (STZ)-induced diabetic rats. Aortic segments were used to investigate the vascular reactivity, protein expression of cyclooxygenase-2 (COX-2) and nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) 1 (NOX1) and superoxide anions levels. RESULTS Atorvastatin treatment did not affect glycemia levels. In diabetic rats, the vascular reactivity to phenylephrine increased compared with controls and the atorvastatin treatment reduced this response. Removal of the endothelium increased the response to phenylephrine in control rats, but not in the diabetic group. Atorvastatin increased the endothelial modulation in diabetic rats. L-NAME (100μM) increased the reactivity in all groups, but this effect was greater in atorvastatin-treated diabetic rats. Indomethacin (10μM) and NS398 (1μM) decreased the contractile response in diabetic rats and atorvastatin reversed these effects, without changing COX-2 expression. Apocynin (30μM) decreased the phenylephrine response in diabetic rats, which also showed increased NOX1 and superoxide anions; these effects were prevented by atorvastatin treatment. CONCLUSIONS The results suggest that treatment with high dose of atorvastatin, independent of glycemia, improves endothelial function in aortas from diabetic rats by reducing the constrictor prostanoids derived from COX-2 and by reducing the oxidative stress by NADPH oxidase, as well as a possible increasing of nitric oxide participation.
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Affiliation(s)
- Fabiana Vieira Simões
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | - Priscila Rossi de Batista
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | - Tatiani Botelho
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | | | - Alessandra Simão Padilha
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil.
| | - Dalton Valentim Vassallo
- Department of Physiological Sciences, Universidade Federal do Espírito Santo (UFES), Vitória, ES, Brazil; Escola Superior de Ciências da Santa Casa de Misericórdia de Vitória (EMESCAM), Vitória, ES, Brazil.
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Gerö D, Szabo C. Glucocorticoids Suppress Mitochondrial Oxidant Production via Upregulation of Uncoupling Protein 2 in Hyperglycemic Endothelial Cells. PLoS One 2016; 11:e0154813. [PMID: 27128320 PMCID: PMC4851329 DOI: 10.1371/journal.pone.0154813] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 04/19/2016] [Indexed: 11/19/2022] Open
Abstract
Diabetic complications are the leading cause of morbidity and mortality in diabetic patients. Elevated blood glucose contributes to the development of endothelial and vascular dysfunction, and, consequently, to diabetic micro- and macrovascular complications, because it increases the mitochondrial proton gradient and mitochondrial oxidant production. Therapeutic approaches designed to counteract glucose-induced mitochondrial reactive oxygen species (ROS) production in the vasculature are expected to show efficacy against all diabetic complications, but direct pharmacological targeting (scavenging) of mitochondrial oxidants remains challenging due to the high reactivity of some of these oxidant species. In a recent study, we have conducted a medium-throughput cell-based screening of a focused library of well-annotated pharmacologically active compounds and identified glucocorticoids as inhibitors of mitochondrial superoxide production in microvascular endothelial cells exposed to elevated extracellular glucose. The goal of the current study was to investigate the mechanism of glucocorticoids' action. Our findings show that glucocorticoids induce the expression of the mitochondrial UCP2 protein and decrease the mitochondrial potential. UCP2 silencing prevents the protective effect of the glucocorticoids on ROS production. UCP2 induction also increases the oxygen consumption and the "proton leak" in microvascular endothelial cells. Furthermore, glutamine supplementation augments the effect of glucocorticoids via further enhancing the expression of UCP2 at the translational level. We conclude that UCP2 induction represents a novel experimental therapeutic intervention in diabetic vascular complications. While direct repurposing of glucocorticoids may not be possible for the therapy of diabetic complications due to their significant side effects that develop during chronic administration, the UCP2 pathway may be therapeutically targetable by other, glucocorticoid-independent pharmacological means.
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Affiliation(s)
- Domokos Gerö
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas, United States of America
- University of Exeter Medical School, Exeter, United Kingdom
- * E-mail:
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas, United States of America
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Cardiovascular Protective Effect of Metformin and Telmisartan: Reduction of PARP1 Activity via the AMPK-PARP1 Cascade. PLoS One 2016; 11:e0151845. [PMID: 26986624 PMCID: PMC4795690 DOI: 10.1371/journal.pone.0151845] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/05/2016] [Indexed: 11/19/2022] Open
Abstract
Hyperglycemia and hypertension impair endothelial function in part through oxidative stress-activated poly (ADP-ribose) polymerase 1 (PARP1). Biguanides and angiotensin II receptor blockers (ARBs) such as metformin and telmisartan have a vascular protective effect. We used cultured vascular endothelial cells (ECs), diabetic and hypertensive rodent models, and AMPKα2-knockout mice to investigate whether metformin and telmisartan have a beneficial effect on the endothelium via AMP-activated protein kinase (AMPK) phosphorylation of PARP1 and thus inhibition of PARP1 activity. The results showed that metformin and telmisartan, but not glipizide and metoprolol, activated AMPK, which phosphorylated PARP1 Ser-177 in cultured ECs and the vascular wall of rodent models. Experiments using phosphorylated/de-phosphorylated PARP1 mutants show that AMPK phosphorylation of PARP1 leads to decreased PARP1 activity and attenuated protein poly(ADP-ribosyl)ation (PARylation), but increased endothelial nitric oxide synthase (eNOS) activity and silent mating type information regulation 2 homolog 1 (SIRT1) expression. Taken together, the data presented here suggest biguanides and ARBs have a beneficial effect on the vasculature by the cascade of AMPK phosphorylation of PARP1 to inhibit PARP1 activity and protein PARylation in ECs, thereby mitigating endothelial dysfunction.
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Dysregulation of matricellular proteins is an early signature of pathology in laminin-deficient muscular dystrophy. Skelet Muscle 2014; 4:14. [PMID: 25075272 PMCID: PMC4114446 DOI: 10.1186/2044-5040-4-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 06/02/2014] [Indexed: 12/21/2022] Open
Abstract
Background MDC1A is a congenital neuromuscular disorder with developmentally complex and progressive pathologies that results from a deficiency in the protein laminin α2. MDC1A is associated with a multitude of pathologies, including increased apoptosis, inflammation and fibrosis. In order to assess and treat a complicated disease such as MDC1A, we must understand the natural history of the disease so that we can identify early disease drivers and pinpoint critical time periods for implementing potential therapies. Results We found that DyW mice show significantly impaired myogenesis and high levels of apoptosis as early as postnatal week 1. We also saw a surge of inflammatory response at the first week, marked by high levels of infiltrating macrophages, nuclear factor κB activation, osteopontin expression and overexpression of inflammatory cytokines. Fibrosis markers and related pathways were also observed to be elevated throughout early postnatal development in these mice, including periostin, collagen and fibronectin gene expression, as well as transforming growth factor β signaling. Interestingly, fibronectin was found to be the predominant fibrous protein of the extracellular matrix in early postnatal development. Lastly, we observed upregulation in various genes related to angiotensin signaling. Methods We sought out to examine the dysregulation of various pathways throughout early development (postnatal weeks 1-4) in the DyW mouse, the most commonly used mouse model of laminin-deficient muscular dystrophy. Muscle function tests (stand-ups and retractions) as well as gene (qRT-PCR) and protein levels (western blot, ELISA), histology (H&E, picrosirius red staining) and immunohistochemistry (fibronectin, TUNEL assay) were used to assess dysregulation of matricelluar protieins. Conclusions Our results implicate the involvement of multiple signaling pathways in driving the earliest stages of pathology in DyW mice. As opposed to classical dystrophies, such as Duchenne muscular dystrophy, the dysregulation of various matricellular proteins appears to be a distinct feature of the early progression of DyW pathology. On the basis of our results, we believe that therapies that may reduce apoptosis and stabilize the homeostasis of extracellular matrix proteins may have increased efficacy if started at a very early age.
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Li J, Peng L, Du H, Wang Y, Lu B, Xu Y, Ye X, Shao J. The Protective Effect of Beraprost Sodium on Diabetic Cardiomyopathy through the Inhibition of the p38 MAPK Signaling Pathway in High-Fat-Induced SD Rats. Int J Endocrinol 2014; 2014:901437. [PMID: 25435878 PMCID: PMC4243139 DOI: 10.1155/2014/901437] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/12/2014] [Accepted: 10/13/2014] [Indexed: 11/23/2022] Open
Abstract
Objective. To investigate the effect of beraprost sodium (BPS) on diabetic cardiomyopathy and the underlying mechanism. Methods. A total of 40 Sprague Dawley rats were randomly divided into the normal control group (N = 10) and the model group (N = 30). The model group was fed a high-fat diet followed by a one-time dose of streptozotocin (STZ) to establish the diabetes mellitus model. After that, rats were randomly divided into two groups with or without BPS intervention. After 8 weeks, we explored the role of the p38 MAPK signaling pathway in inflammation, oxidative stress, cardiac morphology, and myocardial apoptosis. Results. Compared with control, the ratio of heart-weight to body-weight and the serum levels of SOD and GSH in the BPS group significantly increased, the expression of p38 MAPK, the serum levels of MDA, TGF-β1, TNF-α, HIF-1α, MMP-9, caspase-3, BNP, ANP, and heart Bax expression significantly decreased, and heart Bcl-2 expression significantly increased. H&E staining in diabetic rats showed the cardiac muscle fibers derangement, the widening gap, the pyknotic and fragmented nuclei, and more apoptosis. Conclusions. BPS effectively showed protective effects on diabetic myocardial cells, possibly through the inhibition of p38 MAPK signaling pathway.
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Affiliation(s)
- Jie Li
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Li Peng
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Hong Du
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Yangtian Wang
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Bin Lu
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Yixin Xu
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Xiaozhen Ye
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
| | - Jiaqing Shao
- Department of Endocrinology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu 210002, China
- *Jiaqing Shao:
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Endothelial dysfunction in diabetes and hypertension: cross talk in RAS, BMP4, and ROS-dependent COX-2-derived prostanoids. J Cardiovasc Pharmacol 2013; 61:204-14. [PMID: 23232839 DOI: 10.1097/fjc.0b013e31827fe46e] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Vascular endothelium regulates cardiovascular function, and endothelial dysfunction is the key initiator for arteriosclerosis and thrombosis and their complications. The endothelium is a dynamic interface that responds to various stimuli and synthesizes and liberates vasoactive molecules such as nitric oxide, prostaglandins, hyperpolarizing factor, and endothelin. Risk factors such as hypertension, hypercholesterolemia, smoking, and hyperglycemia impair the ability of the endothelium to respond to physical or chemical stimulation appropriately, and increased oxidative stress is believed to be a major culprit. This brief article reviews the interplay among several oxidative stress regulators in the vascular wall and highlights therapeutic relevance through deeper understanding of the interplay between the renin-angiotensin system, nicotinamide adenine dinucleotide phosphate, reduced oxidase, bone morphogenic protein 4, and cyclooxygenase 2-derived prostaglandins as a concerted pathogenic cascade in inducing and maintaining endothelial dysfunction in hypertension and diabetes.
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Becher PM, Lindner D, Fröhlich M, Savvatis K, Westermann D, Tschöpe C. Assessment of cardiac inflammation and remodeling during the development of streptozotocin-induced diabetic cardiomyopathy in vivo: a time course analysis. Int J Mol Med 2013; 32:158-64. [PMID: 23652584 DOI: 10.3892/ijmm.2013.1368] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/23/2013] [Indexed: 11/06/2022] Open
Abstract
In this study, we examined cardiac inflammation, fibrosis and left ventricular (LV) function during the development of streptozotocin (STZ)-induced diabetic cardiomyopathy using an animal model of diabetes mellitus (DM). Diabetes was induced in 22 Sprague‑Dawley rats by an intraperitoneal single injection of STZ (70 mg/kg). Non-diabetic animals served as the controls (n=6). LV function was documented using the conductance catheter technique 2 and 6 weeks after the induction of diabetes. Cardiac tissue was analyzed for cardiac immune cell infiltration, oxidative stress and remodeling in rats with STZ-induced diabetes at 2 different time points by immunohistochemistry. Cardiac function was significantly impaired in the diabetic animals. After 2 weeks, the induction of diabetes resulted in impaired cardiac function indexed by a decrease in systolic and diastolic LV function. This impairment of LV performance continued for up to 6 weeks after the STZ injection. This was associated with an increase in cardiac CD3+ and CD8a+ immune cell invasion and fibrosis, indexed by an increase in collagen content (p<0.05). Furthermore, oxidative stress response and matrix remodeling were increased after 2 weeks and this continued for up to 6 weeks after the induction of diabetes. In conclusion, cardiac dysfunction is associated with cardiac inflammation and adverse remodeling in experimental diabetic cardiomyopathy. Our results suggest that the model of STZ-induced diabetic cardiomyopathy is a robust model for investigating cardiac immune response and LV remodeling processes under diabetic conditions.
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Affiliation(s)
- P M Becher
- Department of Cardiology and Pneumology, Charité University Hospital Berlin, Campus Benjamin Franklin, D-12200 Berlin, Germany
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13
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Salutary effect of Cassia auriculata L. Leaves on hyperglycemia-induced atherosclerotic environment in streptozotocin rats. Cardiovasc Toxicol 2012; 11:308-15. [PMID: 21800129 DOI: 10.1007/s12012-011-9120-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Diabetes mellitus is very often associated with dyslipidemia, increased oxidative stress and endothelial dysfunction that could develop atherosclerosis and consequently cardiovascular diseases. Medicinal plants with reputed traditional use to treat diabetes and cardiovascular diseases might provide valuable drugs. Therefore, the present study was designed to evaluate anti-atherosclerotic potential of aqueous extract of Cassia auriculata L. leaves in streptozotocin (STZ)-induced diabetic rats. The rats were rendered diabetic by STZ (45 mg/kg, ip). Diabetic rats were orally administered C. auriculata leaf extract at 400 mg/kg dose daily for 21 days. The supplementation of extract to the diabetic rats produced significant reduction in fasting blood glucose along with significant reversal in altered serum lipid profile and apolipoprotein B. Lipid peroxidation was found to be significantly suppressed in extract-fed diabetic rats. The significant reduction in serum levels of oxidized low-density lipoprotein, soluble vascular cell adhesion molecule and plasma fibrinogen with a concomitant elevation in serum nitric oxide was observed in diabetic rats following treatment with extract. Histopathological examination of heart myocardium of extract-treated diabetic rats revealed reversal of fatty change toward normal. These results suggest that C. auriculata aqueous leaf extract exhibits anti-atherosclerotic role in the diabetic state and it indicates toward the notion that extract may help to prevent the progression of cardiovascular diseases.
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Semprun-Prieto LC, Sukhanov S, Yoshida T, Rezk BM, Gonzalez-Villalobos RA, Vaughn C, Michael Tabony A, Delafontaine P. Angiotensin II induced catabolic effect and muscle atrophy are redox dependent. Biochem Biophys Res Commun 2011; 409:217-21. [PMID: 21570954 DOI: 10.1016/j.bbrc.2011.04.122] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 04/25/2011] [Indexed: 02/07/2023]
Abstract
Angiotensin II (Ang II) causes skeletal muscle wasting via an increase in muscle catabolism. To determine whether the wasting effects of Ang II were related to its ability to increase NADPH oxidase-derived reactive oxygen species (ROS) we infused wild-type C57BL/6J or p47(phox)(-/-) mice with vehicle or Ang II for 7days. Superoxide production was increased 2.4-fold in the skeletal muscle of Ang II infused mice, and this increase was prevented in p47(phox)(-/-) mice. Apocynin treatment prevented Ang II-induced superoxide production in skeletal muscle, consistent with Ang II increasing NADPH oxidase derived ROS. Ang II induced loss of body and skeletal muscle weight in C57BL/6J mice, whereas the reduction was significantly attenuated in p47(phox)(-/-) animals. The reduction of skeletal muscle weight caused by Ang II was associated with an increase of proteasome activity, and this increase was completely prevented in the skeletal muscle of p47(phox)(-/-) mice. In conclusion, Ang II-induced skeletal muscle wasting is in part dependent on NADPH oxidase derived ROS.
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Affiliation(s)
- Laura C Semprun-Prieto
- Heart and Vascular Institute, Tulane University School of Medicine, Tulane University Heart and Vascular Institute, 1430 Tulane Avenue, SL 48, New Orleans, LA 70112, United States
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15
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Yoshioka I, Tsujihata M, Akanae W, Nonomura N, Okuyama A. Angiotensin Type-1 Receptor Blocker Candesartan Inhibits Calcium Oxalate Crystal Deposition in Ethylene Glycol-Treated Rat Kidneys. Urology 2011; 77:1007.e9-1007.e14. [DOI: 10.1016/j.urology.2010.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/28/2010] [Accepted: 11/14/2010] [Indexed: 10/18/2022]
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Sun D, Shen M, Li J, Li W, Zhang Y, Zhao L, Zhang Z, Yuan Y, Wang H, Cao F. Cardioprotective effects of tanshinone IIA pretreatment via kinin B2 receptor-Akt-GSK-3β dependent pathway in experimental diabetic cardiomyopathy. Cardiovasc Diabetol 2011; 10:4. [PMID: 21232147 PMCID: PMC3033797 DOI: 10.1186/1475-2840-10-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Accepted: 01/13/2011] [Indexed: 11/26/2022] Open
Abstract
Aims Diabetic cardiomyopathy, characterized by myocardial structural and functional changes, is a specific cardiomyopathy develops in patients with diabetes mellitus. The present study was to investigate the role of kinin B2 receptor-Akt-glycogen synthase kinase (GSK)-3β signalling pathway in mediating the protective effects of tanshinone IIA (TSN) on diabetic cardiomyopathy. Methods and results Streptozocin (STZ) induced diabetic rats (n = 60) were randomized to receive TSN, TSN plus HOE140 (a kinin B2 receptor antagonist), or saline. Healthy Sprague-Dawley (SD) rats (n = 20) were used as control. Left ventricular function, myocardial apoptosis, myocardial ultrastructure, Akt, GSK-3β and NF-κB phosphorylation, the expression of TNF-α, IL-6 and myeloperoxidase (MPO) were examined. Cardiac function was well preserved as evidenced by increased left ventricular ejection fraction (LVEF) and ± dp/dt (maximum speed of contraction/relaxation), along with decreased myocardial apoptotic death after TSN administration. TSN pretreatment alleviated mitochondria ultrastructure changes. TSN also enhanced Akt and GSK-3β phosphorylation and inhibited NF-κB phosphorylation, resulting in decreased TNF-α, IL-6 and MPO activities. Moreover, pretreatment with HOE140 abolished the beneficial effects of TSN: a decrease in LVEF and ± dp/dt, an inhibition of cardiomyocyte apoptosis, a destruction of cardiomyocyte mitochondria cristae, a reduction of Akt and GSK-3β phosphorylation, an enhancement of NF-κB phosphorylation and an increase of TNF-α, IL-6 and MPO production. Conclusion These data indicated that TSN is cardioprotective in the context of diabetic cardiomyopathy through kinin B2 receptor-Akt-GSK-3β dependent pathway.
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Affiliation(s)
- Dongdong Sun
- Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
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17
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Ahn HY, Kim CH, Ha TS. Epigallocatechin-3-gallate Regulates NADPH Oxidase Expression in Human Umbilical Vein Endothelial Cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2010; 14:325-9. [PMID: 21165332 DOI: 10.4196/kjpp.2010.14.5.325] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 10/16/2010] [Accepted: 10/18/2010] [Indexed: 11/15/2022]
Abstract
Vascular NADPH oxidase plays a pivotal role in producing superoxide in endothelial cells and thus acts in the initiation and development of inflammatory cardiovascular diseases such as atherosclerosis. Epigallocatechin-3-gallate (EGCG), the major catechin derived from green tea, has multiple beneficial effects for treating cardiovascular disease but the effect of EGCG on the expression of vascular NADPH oxidase remains unknown. In this study, we investigated the mechanism(s) by which EGCG might inhibit the expression of subunits of NADPH oxidase, namely p47(phox), p67(phox) and p22(phox), induced by angiotensin II (Ang II) in human umbilical vein endothelial cells. Ang II increased the expression levels of p47(phox), p67(phox), and p22(phox), but EGCG counteracted this effect on p47(phox). Moreover, EGCG did not affect the production of reactive oxygen species induced by Ang II. These data suggest a novel mechanism whereby EGCG might provide direct vascular benefits for treating inflammatory cardiovascular diseases.
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Affiliation(s)
- Hee Yul Ahn
- Department of Pharmacology, College of Medicine, Chungbuk University, Cheongju 361-763, Korea
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Kamper M, Tsimpoukidi O, Chatzigeorgiou A, Lymberi M, Kamper EF. The antioxidant effect of angiotensin II receptor blocker, losartan, in streptozotocin-induced diabetic rats. Transl Res 2010; 156:26-36. [PMID: 20621034 DOI: 10.1016/j.trsl.2010.05.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 04/28/2010] [Accepted: 05/04/2010] [Indexed: 12/21/2022]
Abstract
We determined the effect of a short-term angiotensin II signaling blockade on vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), nitric oxide (NO), and malondialdehyde (MDA) (index of lipid peroxidation) levels in the systemic circulation and on peroxynitrite generation and insulitis development in the streptozotocin (STZ) diabetic rats' pancreas. Diabetes was induced in Wistar rats by intraperitoneal STZ injection. Diabetic rats were treated for 1 week with losartan (20 mg/kg/body weight/day in the drinking water), and pancreas and blood were collected for histochemical, immunohistochemical, and biochemical studies. Diabetic rats showed greater VEGF, sICAM-1, NO, and MDA levels, a high score of insulitis, increased nitrotyrosine staining, and markedly reduced pancreatic insulin content when compared with controls. Losartan treatment suppressed the excessive NO and lipid peroxidation production systemically without restoring them to that of healthy subjects and reduced VEGF levels while leaving sICAM-1 levels unchanged. The insulitis score and nitrotyrosine staining were reduced, whereas the pancreatic islets and the beta-cell area were increased significantly in the treated group, indicating the reduction of inflammation and nitrosative stress and an early regeneration of beta-cell mass in the pancreas. Conclusively, in the STZ diabetic rat model, even a short-term losartan treatment improves oxidative and nitrosative stress systemically and locally, improving the islets' environment and accelerating beta-cell regeneration.
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Affiliation(s)
- Maria Kamper
- Department of Experimental Physiology, Medical School, University of Athens, GR-115 27, Athens, Greece.
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19
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Diamond-Stanic MK, Henriksen EJ. Direct inhibition by angiotensin II of insulin-dependent glucose transport activity in mammalian skeletal muscle involves a ROS-dependent mechanism. Arch Physiol Biochem 2010; 116:88-95. [PMID: 20384568 PMCID: PMC3298971 DOI: 10.3109/13813451003758703] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
No previous study has investigated how the vaso-constrictive peptide Ang II impacts insulin action in isolated mammalian skeletal muscle. We investigated the molecular actions of Ang II on insulin signalling and glucose transport in skeletal muscle from lean Zucker rats. Soleus strips were incubated with insulin (5 mU/ml) and/or Ang II (500 nM) for 2 hours. Ang II caused significant (p < 0.05) inhibition of insulin-stimulated glucose transport (39%) and decreased phosphorylation of Akt Ser(473) (37%) and glycogen synthase kinase-3beta Ser(9) (42%) without affecting phosphorylation of IRS-1 Ser(307) or p38 MAPK. We used the superoxide dismutase mimetic, tempol (1 mM), to determine if reactive oxygen species (ROS) contribute to Ang II-mediated insulin resistance. Tempol partially reversed (42%) Ang II-induced inhibition of insulin-stimulated glucose transport. These results indicate that Ang II inhibits distal insulin signalling and insulin-stimulated glucose transport in isolated mammalian skeletal muscle, and that this effect is partially mediated by ROS.
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Affiliation(s)
- Maggie K Diamond-Stanic
- Muscle Metabolism Laboratory, Department of Physiology and Arizona Diabetes Program, University of Arizona College of Medicine, Tucson, AZ 85721-0093, USA
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Csibi A, Communi D, Müller N, Bottari SP. Angiotensin II inhibits insulin-stimulated GLUT4 translocation and Akt activation through tyrosine nitration-dependent mechanisms. PLoS One 2010; 5:e10070. [PMID: 20383279 PMCID: PMC2850936 DOI: 10.1371/journal.pone.0010070] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Accepted: 03/11/2010] [Indexed: 12/20/2022] Open
Abstract
Angiotensin II (Ang II) plays a major role in the pathogenesis of insulin resistance and diabetes by inhibiting insulin's metabolic and potentiating its trophic effects. Whereas the precise mechanisms involved remain ill-defined, they appear to be associated with and dependent upon increased oxidative stress. We found Ang II to block insulin-dependent GLUT4 translocation in L6 myotubes in an NO- and O2.−-dependent fashion suggesting the involvement of peroxynitrite. This hypothesis was confirmed by the ability of Ang II to induce tyrosine nitration of the MAP kinases ERK1/2 and of protein kinase B/Akt (Akt). Tyrosine nitration of ERK1/2 was required for their phosphorylation on Thr and Tyr and their subsequent activation, whereas it completely inhibited Akt phosphorylation on Ser473 and Thr308 as well as its activity. The inhibitory effect of nitration on Akt activity was confirmed by the ability of SIN-1 to completely block GSK3α phosphorylation in vitro. Inhibition of nitric oxide synthase and NAD(P)Hoxidase and scavenging of free radicals with myricetin restored insulin-stimulated Akt phosphorylation and GLUT4 translocation in the presence of Ang II. Similar restoration was obtained by inhibiting the ERK activating kinase MEK, indicating that these kinases regulate Akt activation. We found a conserved nitration site of ERK1/2 to be located in their kinase domain on Tyr156/139, close to their active site Asp166/149, in agreement with a permissive function of nitration for their activation. Taken together, our data show that Ang II inhibits insulin-mediated GLUT4 translocation in this skeletal muscle model through at least two pathways: first through the transient activation of ERK1/2 which inhibit IRS-1/2 and second through a direct inhibitory nitration of Akt. These observations indicate that not only oxidative but also nitrative stress play a key role in the pathogenesis of insulin resistance. They underline the role of protein nitration as a major mechanism in the regulation of Ang II and insulin signaling pathways and more particularly as a key regulator of protein kinase activity.
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Affiliation(s)
- Alfredo Csibi
- Laboratoire de Bioénergétique Fondamentale et Appliquée, INSERM U884, Grenoble Universités, Grenoble, France
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Sixt S, Beer S, Blüher M, Korff N, Peschel T, Sonnabend M, Teupser D, Thiery J, Adams V, Schuler G, Niebauer J. Long- but not short-term multifactorial intervention with focus on exercise training improves coronary endothelial dysfunction in diabetes mellitus type 2 and coronary artery disease. Eur Heart J 2009; 31:112-9. [PMID: 19793768 DOI: 10.1093/eurheartj/ehp398] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Patients with type 2 diabetes mellitus (T2DM) suffer from accelerated coronary artery disease. We assessed the effects of a multifactorial intervention with focus on exercise training on coronary endothelial function, vascular structure, and inflammation in serum and skeletal muscle biopsies, including mRNA expression of diabetes candidate genes. METHODS AND RESULTS Twenty-three patients were randomized to either 4 weeks in-hospital exercise training (6 x 15 min bicycle/day, 5 days/week) and a hypocaloric diet, followed by a 5 months ambulatory program (30 min ergometer/day, 5 days/week, plus 1 h group exercise/week), or a control group. At the beginning of the study, at 4 weeks, and after 6 months changes in diameter of coronary arteries in response to acetylcholine and mean peak flow velocity were invasively measured; intramural plaques were assessed by intravascular ultrasound. Six months of intervention led to significant improvement of coronary endothelial function, whereas intramural plaque burden remained unchanged. After 4 weeks, endothelial function remained unchanged, however, lowest values for fasting glucose, HbA1c, high-sensitive C-reactive protein, total and LDL-cholesterol, and highest values for mRNA expression in skeletal muscle of p22, gp91, haem oxygenase 1, peroxisome proliferator activator receptor (PPAR) alpha and gamma were observed. There was a continuous increase for AdipoR1, AdipoR2, Glut4, interleukin-6, endothelial nitric oxide synthase, and PPARgamma-coactivator-1alpha mRNA expression in skeletal muscle. CONCLUSION This is the first study to demonstrate improvement in coronary endothelial function by a multifactorial intervention which focused on exercise training in patients with T2DM. This coincided with improved markers of hyperglycaemia, insulin sensitivity, and inflammation both in serum and skeletal muscle biopsies.
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Affiliation(s)
- Sebastian Sixt
- Department of Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
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Westermann D, Walther T, Savvatis K, Escher F, Sobirey M, Riad A, Bader M, Schultheiss HP, Tschöpe C. Gene deletion of the kinin receptor B1 attenuates cardiac inflammation and fibrosis during the development of experimental diabetic cardiomyopathy. Diabetes 2009; 58:1373-81. [PMID: 19276445 PMCID: PMC2682670 DOI: 10.2337/db08-0329] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Diabetic cardiomyopathy is associated with increased mortality in patients with diabetes. The underlying pathology of this disease is still under discussion. We studied the role of the kinin B1 receptor on the development of experimental diabetic cardiomyopathy. RESEARCH DESIGN AND METHODS We utilized B1 receptor knockout mice and investigated cardiac inflammation, fibrosis, and oxidative stress after induction of streptozotocin (STZ)-induced diabetes. Furthermore, the left ventricular function was measured by pressure-volume loops after 8 weeks of diabetes. RESULTS B1 receptor knockout mice showed an attenuation of diabetic cardiomyopathy with improved systolic and diastolic function in comparison with diabetic control mice. This was associated with a decreased activation state of the mitogen-activated protein kinase p38, less oxidative stress, as well as normalized cardiac inflammation, shown by fewer invading cells and no increase in matrix metalloproteinase-9 as well as the chemokine CXCL-5. Furthermore, the profibrotic connective tissue growth factor was normalized, leading to a reduction in cardiac fibrosis despite severe hyperglycemia in mice lacking the B1 receptor. CONCLUSIONS These findings suggest that the B1 receptor is detrimental in diabetic cardiomyopathy in that it mediates inflammatory and fibrotic processes. These insights might have useful implications on future studies utilizing B1 receptor antagonists for treatment of human diabetic cardiomyopathy.
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Affiliation(s)
- Dirk Westermann
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Thomas Walther
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Konstantinos Savvatis
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Felcicitas Escher
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Meike Sobirey
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Alexander Riad
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Michael Bader
- Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Heinz-Peter Schultheiss
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Carsten Tschöpe
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
- Corresponding author: Carsten Tschöpe,
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Effect of metoprolol on vulnerable plaque in rabbits by changing shear stress around plaque and reducing inflammation. Eur J Pharmacol 2009; 613:79-85. [PMID: 19356726 DOI: 10.1016/j.ejphar.2009.03.075] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 01/22/2009] [Accepted: 03/31/2009] [Indexed: 11/22/2022]
Abstract
The beta-adrenoceptor antagonists are known to reduce cardiovascular events, but less is known about their effects on vulnerable plaque. The purpose of this study is to explore the role of metoprolol on vulnerable plaque and the possible mechanism. Vulnerable plaque model was established by local transfection with p53 gene in New Zealand Rabbits. Metoprolol treatment attenuated vessel positive remodeling and reduced vulnerability index (1.61+/-0.58 vs. 2.33+/-0.12, P<0.01). Although the difference did not reach statistical significance, the rate of rupture of atherosclerotic plaque (31% vs. 75%) and intima-media thickness (0.05+/-0.01 vs. 0.08+/-0.01 cm) were less in the metoprolol group than in the control group. The level of shear stress-related inflammatory cytokines such as intercellular adhesion molecule 1 (ICAM-1), vascular adhesion molecule 1 (VCAM-1), matrix metalloproteinase 1 (MMP-1), were lower in the metoprolol group than in the control group (P<0.01). Compared with control group, total cholesterol and low-density lipoprotein cholesterol were lower (P<0.01) in the metoprolol group. After metoprolol treatment, shear stress increased, and was not different to baseline (physiological shear stress, P>0.05). Shear stress and vulnerability index showed a negative correlation. These findings suggest that metoprolol could inhibit the development of atherosclerosis and stabilize vulnerable plaque by regulation of lipid and reduction of inflammation, in which the change from low shear stress to physiological shear stress around plaque may play an important role.
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Zhang R, Bai YG, Lin LJ, Bao JX, Zhang YY, Tang H, Cheng JH, Jia GL, Ren XL, Ma J. Blockade of AT1 receptor partially restores vasoreactivity, NOS expression, and superoxide levels in cerebral and carotid arteries of hindlimb unweighting rats. J Appl Physiol (1985) 2009; 106:251-8. [DOI: 10.1152/japplphysiol.01278.2007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies have demonstrated activation of the local renin-angiotensin system in hindlimb unweighting (HU) rat vasculature. The present study intended to identify the effects of blockade of angiotensin II (ANG II) type 1 (AT1) receptors with losartan on vascular reactivity, nitric oxide synthase (NOS) expression, and superoxide anion (O2•−) levels in 3-wk HU rat cerebral and carotid arteries. Three weeks later, vasoconstriction, vasodilatation, endothelial NOS (eNOS) and inducible NOS (iNOS) protein, as well as O2•− levels in rat cerebral and carotid arteries were examined. We found that HU enhanced maximal response to KCl/5-hydroxytryptamine ( P < 0.01) in basilar arteries and KCl/phenylephrine ( P < 0.05) in common carotid arteries from HU rats. Acetylcholine induced concentration-dependent vasodilatation in all the artery rings, but with significantly smaller amplitude in basilar ( P < 0.01) and common carotid ( P < 0.05) arteries from HU rats than those from control rats. Chronic treatment with losartan partially restored response to vasoconstrictors and acetylcholine-induced vasodilatation in basilar ( P < 0.01) and common carotid ( P < 0.05) arteries from losartan-treated HU rats. Furthermore, iNOS content in cerebral arteries and eNOS/iNOS content in carotid arteries were significantly ( P < 0.01) increased in HU rats. Meanwhile, HU increased O2•− levels in all the layers of these arteries. However, losartan restored NOS content and O2•− levels toward normal. These results suggested that the HU-induced enhancement of vasoconstriction and reduction in endothelium-dependent relaxation involved alterations in O2•− and NOS content through an ANG II/AT1 receptor signaling pathway.
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Riad A, Westermann D, Van Linthout S, Mohr Z, Uyulmaz S, Becher PM, Rütten H, Wohlfart P, Peters H, Schultheiss HP, Tschöpe C. Enhancement of endothelial nitric oxide synthase production reverses vascular dysfunction and inflammation in the hindlimbs of a rat model of diabetes. Diabetologia 2008; 51:2325-32. [PMID: 18825362 DOI: 10.1007/s00125-008-1159-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 07/21/2008] [Indexed: 01/28/2023]
Abstract
AIMS/HYPOTHESIS Reduced bioavailability of nitric oxide (NO) is a hallmark of diabetes mellitus-induced vascular complications. In the present study we investigated whether a pharmacological increase of endothelial NO synthase (eNOS) production can restore the impaired hindlimb flow in a rat model of severe diabetes. METHODS A model of diabetes mellitus was induced in male Sprague-Dawley rats by a single injection of streptozotozin. Rats were treated chronically with the eNOS transcription enhancer AVE3085 (10 mg [kg body weight](-1) day(-1); p.o.) or vehicle for 48 days and compared with controls. Endothelial function and arterial BP were investigated in vivo using an autoperfused hindlimb model and TIP-catheter measurement, respectively. Protein production of eNOS, total and phosphorylated vasodilator-stimulated phosphoprotein (VASP) were assessed in their quadriceps muscle tissue, whereas cyclic GMP (cGMP) concentrations were assessed in blood plasma. RNA levels of intracellular and vascular cell adhesion molecules (ICAM-1 and VCAM-1) were measured by real-time PCR. RESULTS Untreated diabetic rats showed significantly reduced quadriceps muscle contents of eNOS (-64%) and phosphorylated VASP (-26%) protein associated with impaired vascular function (maximum vasodilatation: -30%, p < 0.05) and enhanced production of ICAM-1 (+121%) and VCAM-1 (+156%). Chronic treatment with AVE3085 did not alter arterial BP or severe hyperglycaemia, but did lead to significantly increased production of eNOS (+95%), cGMP (+128%) and VASP phosphorylation (+65%) as well as to improved vascular function (+36%) associated with reduced production of ICAM-1 (-36%) and VCAM-1 (-58%). CONCLUSIONS/INTERPRETATION In a rat model of severe diabetes, pharmacological enhancement of impaired eNOS production and NO-cGMP signalling by AVE3085 restores altered hindlimb blood flow and prevents vascular inflammation.
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Affiliation(s)
- A Riad
- Department of Cardiology and Pneumology, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12206, Berlin, Germany
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Uehara G, Takeda H. Relative Effects of Telmisartan, Candesartan and Losartan on Alleviating Arterial Stiffness in Patients with Hypertension Complicated by Diabetes Mellitus: An Evaluation Using the Cardio-Ankle Vascular Index (CAVI). J Int Med Res 2008; 36:1094-102. [DOI: 10.1177/147323000803600529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Using the cardio-ankle vascular index (CAVI) as an indicator, we assessed improvement of arterial stiffness in 95 outpatients with hypertension complicated by type 2 diabetes mellitus who were treated orally for ≤ 12 months with telmisartan 40 mg/day, losartan 50 mg/day or candesartan 8 mg/day. At 1 year, in the telmisartan and losartan groups CAVI did not change whereas in the candesartan group CAVI showed a statistically significant decrease of 2.70%. Although telmisartan is believed to enhance the activity of peroxisome proliferator-activated receptor (PPAR-γ) in vitro, it did not ameliorate arterial stiffness in our patients. Candesartan, however, improved arterial stiffness independently of blood pressure lowering and without PPAR-γ agonist action, possibly by direct action resulting from its potent affinity and binding capacity for the angiotensin II type 1 receptor. We conclude that candesartan is a potentially useful therapy against arterial stiffness in hypertensive patients with type 2 diabetes mellitus.
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Affiliation(s)
- G Uehara
- Department of Internal Medicine, Takeda Clinic, Kanagawa, Japan
| | - H Takeda
- Department of Internal Medicine, Takeda Clinic, Kanagawa, Japan
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Riad A, Du J, Stiehl S, Westermann D, Mohr Z, Sobirey M, Doehner W, Adams V, Pauschinger M, Schultheiss HP, Tschöpe C. Low-dose treatment with atorvastatin leads to anti-oxidative and anti-inflammatory effects in diabetes mellitus. Eur J Pharmacol 2007; 569:204-11. [PMID: 17669395 DOI: 10.1016/j.ejphar.2007.04.065] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 04/24/2007] [Accepted: 04/25/2007] [Indexed: 11/17/2022]
Abstract
We investigated whether atorvastatin, given in a dose to low to influence the lipid profile, has any effect on oxidative stress, inflammation and endothelial function under streptozotocin-induced diabetic conditions. Diabetes mellitus was induced in male Sprague Dawley rats by a single injection of streptozotocin. Rats were treated chronically with atorvastatin (50 mg/kg/day; p.o.) or vehicle until day 48 and compared with controls. NAD(P)H activity, protein expression nuclear factor-kappaBp65 (NF-kappaBp65) and phosphorylation of the extracellular signal-regulated kinase (ERK1/2) were assessed in the quadriceps muscle. Protein and mRNA levels of intracellular and vascular adhesion molecules (ICAM-1, VCAM-1) and cytokines were measured by Taqman or immunohistochemistry staining, respectively. Endothelial function was investigated in vivo using the autoperfused hind limb model. Diabetic groups displayed similar severe hyperglycemia. Untreated diabetic rats showed enhanced NAD(P)H activity, activation of the ERK1/2/NF-kappaBp65-pathway, enhanced expression of cytokines and cellular adhesion molecules and impaired vascular function. Low-dose therapy by atorvastatin did not alter the lipid profile but led to a reduction of NAD(P)H activity (-28%, P<0.05) associated with reduced protein expression of NF-kappaBp65 (-53%, P<0.05) and phosphorylation of its regulator mitogen-activated protein kinase (MAPK) ERK1/2 in diabetic rats. Also inflammatory markers were reduced after atorvastatin treatment indexed by reduced mRNA expression of VCAM-1 (-24%), tumor necrosis factor alpha (-59%) and interleukin 1beta (-50%) and reduced ICAM-1 (-81%) and VCAM-1 (-74%) positive staining. These beneficial effects were associated with improved endothelium-dependent vasodilatation (maximal vasodilatation: +101%; P<0.05). Lipid-independent anti-oxidative and anti-inflammatory effects of low-dose atorvastatin involving the ERK1/2/NF-kappaB-pathway are sufficient to improve endothelial function under experimental diabetic conditions.
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Affiliation(s)
- Alexander Riad
- Department of Cardiology and Pneumology, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12206 Berlin, Germany
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Riad A, Unger D, Du J, Westermann D, Mohr Z, Sobirey M, Dorenkamp M, Schultheiss HP, Tschöpe C. Chronic inhibition of p38MAPK improves cardiac and endothelial function in experimental diabetes mellitus. Eur J Pharmacol 2007; 554:40-5. [PMID: 17097634 DOI: 10.1016/j.ejphar.2006.08.065] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 08/19/2006] [Accepted: 08/23/2006] [Indexed: 01/29/2023]
Abstract
To investigate the influence of p38 mitogen activated kinase (p38MAPK) on the development of diabetic cardiac and endothelial dysfunction, we assessed left ventricular and vascular function as well as inflammatory markers in diabetic rats after chronic pharmacological inhibition of p38MAPK. Diabetes mellitus was induced in rats by a single injection of streptozotocin. Rats were treated with the p38MAPK inhibitor SB 239063 (40 mg/kg/day, p.o.) or vehicle. 48 days after diabetes mellitus-induction, left ventricular function and vascular function were assessed in vivo by TIP-catheter and the autoperfused hindlimb, respectively. Cell adhesion molecules staining was quantified immunohistochemically in the heart and quadriceps muscle, respectively, as well as cardiac phosphorylation of p38MAPK by Western blot analysis. Treated and untreated diabetic groups displayed similar severe hyperglycemia. Left ventricular and endothelial function were impaired in the untreated diabetic group compared to controls (dp/dtmax: -40%, dp/dtmin: +49%, maximal vasodilatation: -57%; P < 0.05) associated with significantly increased cardiac (3-fold) and peripheral cell adhesion molecules staining, respectively. Treatment of diabetic rats with SB 239063 led to a significant reduction of diabetes-induced enhancement of p38MAPK phosphorylation associated with improved left ventricular function (dp/dtmax: +39%, dp/dtmin: +47%; P < 0.05) and peripheral endothelial function (maximal vasodilatation: +71%; P < 0.05) under diabetic conditions. This was associated with reduced cardiac and peripheral inflammation indexed by reduced adhesion molecules content. Pharmacological inhibition of p38MAPK is sufficient to mitigate the development of diabetic cardiac and endothelial dysfunction despite of hyperglycemia. Our data suggest that the anti-inflammatory properties due to p38MAPK inhibition contribute to these beneficial cardiovascular effects.
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Affiliation(s)
- Alexander Riad
- Department of Cardiology and Pneumology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany
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Clermont A, Bursell SE, Feener EP. Role of the angiotensin II type 1 receptor in the pathogenesis of diabetic retinopathy: effects of blood pressure control and beyond. J Hypertens 2006; 24:S73-80. [PMID: 16601577 DOI: 10.1097/01.hjh.0000220410.69116.f8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Diabetic retinopathy is characterized by both functional and morphological changes in the retinal microvessels that can lead to macular edema, neovascularization, and vision loss. Hypertension has been identified as a major risk factor for diabetic retinopathy and randomized clinical trials have shown that reduction of blood pressure using angiotensin converting enzyme (ACE) inhibitors reduces the progression of diabetic retinopathy. The major components of the renin-angiotensin system have been identified in ocular tissues. Activation of angiotensin II type 1 (AT1) receptors expressed on retinal endothelial cells and pericytes has been implicated in contributing to the microvascular abnormalities in diabetic retinopathy. We have examined the experimental and clinical evidence for the role of the renin-angiotensin system in the pathogenesis of diabetic retinopathy, including the effects of ACE inhibition and AT1-receptor antagonism on diabetes-induced abnormalities in retinal hemodynamics, vascular permeability, and leukostasis; retinal neovascularization in rodent models of oxygen-induced retinopathy; and results from randomized clinical trials that have investigated the effects of ACE inhibitors on the progression of diabetic retinopathy in diabetic patients in the absence or presence of hypertension. The effects of AT1-receptor antagonism on the retina have been attributed to decreases in systemic blood pressure and the concomitant reduction in mechanical vascular stretch, in addition to the intraocular effects blocking AT1-receptor stimulation of retinal endothelial cells and pericytes. Results from the current DIabetic REtinopathy Candesartan Trials program will evaluate the potential of the AT1-receptor as a therapeutic target for diabetic retinopathy.
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