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Targeting endothelial metaflammation to counteract diabesity cardiovascular risk: Current and perspective therapeutic options. Pharmacol Res 2017; 120:226-241. [PMID: 28408314 DOI: 10.1016/j.phrs.2017.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/21/2017] [Accepted: 04/07/2017] [Indexed: 02/08/2023]
Abstract
The association of obesity and diabetes, termed "diabesity", defines a combination of primarily metabolic disorders with insulin resistance as the underlying common pathophysiology. Cardiovascular disorders associated with diabesity represent the leading cause of morbidity and mortality in the Western world. This makes diabesity, with its rising impacts on both health and economics, one of the most challenging biomedical and social threats of present century. The emerging comprehension of the genes whose alteration confers inter-individual differences on risk factors for diabetes or obesity, together with the potential role of genetically determined variants on mechanisms controlling responsiveness, effectiveness and safety of anti-diabetic therapy underlines the need of additional knowledge on molecular mechanisms involved in the pathophysiology of diabesity. Endothelial cell dysfunction, resulting from the unbalanced production of endothelial-derived vascular mediators, is known to be present at the earliest stages of insulin resistance and obesity, and may precede the clinical diagnosis of diabetes by several years. Once considered as a mere consequence of metabolic abnormalities, it is now clear that endothelial dysfunctional activity may play a pivotal role in the progression of diabesity. In the vicious circle where vascular defects and metabolic disturbances worsen and reinforce each other, a low-grade, chronic, and 'cold' inflammation (metaflammation) has been suggested to serve as the pathophysiological link that binds endothelial and metabolic dysfunctions. In this paradigm, it is important to consider how traditional antidiabetic treatments (specifically addressing metabolic dysregulation) may directly impact on inflammatory processes or cardiovascular function. Indeed, not all drugs currently available to treat diabetes possess the same anti-inflammatory potential, or target endothelial cell function equally. Perspective strategies pointing at reducing metaflammation or directly addressing endothelial dysfunction may disclose beneficial consequences on metabolic regulation. This review focuses on existing and potential new approaches ameliorating endothelial dysfunction and vascular inflammation in the context of diabesity.
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Luconi M, Cantini G, Ceriello A, Mannucci E. Perspectives on cardiovascular effects of incretin-based drugs: From bedside to bench, return trip. Int J Cardiol 2017; 241:302-310. [PMID: 28285800 DOI: 10.1016/j.ijcard.2017.02.126] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/24/2017] [Indexed: 12/19/2022]
Abstract
Recently, cardiovascular outcome trials with glucose-lowering drugs used in type 2 diabetes mellitus, namely glucagon-like peptide-1 receptor agonists (GLP-1RA), liraglutide and semaglutide, showed a reduction in cardiovascular events, which had not been observed in trials with other incretin-based drugs, such as lixisenatide or with dipeptidyl peptidase-4 inhibitors (DPP4i). Mechanisms underlying the observed cardiovascular differences between DPP4i and GLP1-RA, and across individual GLP1-RA are poorly understood. This review is aimed at collecting and summarizing available evidence from experimental and mechanistic studies on the action of GLP1-RA and DPP4i on the cardiovascular system, both deriving from clinical and pre-clinical sources. The results of cardiovascular outcome trials are interpreted on the basis of the experimental preclinical data available, paying particular attention to the heart failure results, and suggesting some novel intriguing hypotheses to explain some of the unexpected findings of cardioprotection of incretin-based drugs. In particular, we discuss the possible contribution to the incretin cardiovascular effects of a direct cardiac action of GLP-1 metabolites through GLP-1 receptor-independent pathways, and of DPP4 substrates other than GLP-1.
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Affiliation(s)
- Michaela Luconi
- Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy.
| | - Giulia Cantini
- Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy
| | - Antonio Ceriello
- Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS) and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain; IRCCS MultiMedica, Milan, Italy
| | - Edoardo Mannucci
- Department of Experimental and Clinical Biomedical Sciences, Endocrinology Unit, University of Florence, Florence, Italy; Diabetes Agency, Careggi Hospital, Florence, Italy.
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Hardigan T, Hernandez C, Ward R, Hoda MN, Ergul A. TLR2 knockout protects against diabetes-mediated changes in cerebral perfusion and cognitive deficits. Am J Physiol Regul Integr Comp Physiol 2017; 312:R927-R937. [PMID: 28336553 DOI: 10.1152/ajpregu.00482.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/25/2017] [Accepted: 02/17/2017] [Indexed: 12/29/2022]
Abstract
The risk of cognitive decline in diabetes (Type 1 and Type 2) is significantly greater compared with normoglycemic patients, and the risk of developing dementia in diabetic patients is doubled. The etiology for this is likely multifactorial, but one mechanism that has gained increasing attention is decreased cerebral perfusion as a result of cerebrovascular dysfunction. The innate immune system has been shown to play a role in diabetic vascular complications, notably through the Toll-like receptor (TLR)-stimulated release of proinflammatory cytokines and chemokines that lead to vascular damage. TLR2 has been implicated in playing a crucial role in the development of diabetic microvascular complications, such as nephropathy, and thus, we hypothesized that TLR2-mediated cerebrovascular dysfunction leads to decreased cerebral blood flow (CBF) and cognitive impairment in diabetes. Knockout of TLR2 conferred protection from impaired CBF in early-stage diabetes and from hyperperfusion in long-term diabetes, prevented the development of endothelium-dependent vascular dysfunction in diabetes, created a hyperactive and anxiolytic phenotype, and protected against diabetes-induced impairment of long-term hippocampal and prefrontal cortex-mediated fear learning. In conclusion, these findings support the involvement of TLR2 in the pathogenesis of diabetic vascular disease and cognitive impairment.
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Affiliation(s)
- Trevor Hardigan
- Department of Physiology, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Caterina Hernandez
- Department of Pharmacology and Toxicology, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia.,Department of Small Animal Behavior Core Facility, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Rebecca Ward
- Department of Neuroscience, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - M Nasrul Hoda
- Department of Medical Laboratory, Imaging and Radiologic Sciences, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia.,Department of Neurology, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia.,Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia; and
| | - Adviye Ergul
- Department of Physiology, University of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia; .,Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia
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Widlansky ME, Puppala VK, Suboc TM, Malik M, Branum A, Signorelli K, Wang J, Ying R, Tanner MJ, Tyagi S. Impact of DPP-4 inhibition on acute and chronic endothelial function in humans with type 2 diabetes on background metformin therapy. Vasc Med 2017; 22:189-196. [PMID: 28145158 DOI: 10.1177/1358863x16681486] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cell culture and animal work indicate that dipeptidyl peptidase-4 (DPP-4) inhibition may exert cardiovascular benefits through favorable effects on the vascular endothelium. Prior human studies evaluating DPP-4 inhibition have shown conflicting results that may in part be related to heterogeneity of background anti-diabetes therapies. No study has evaluated the acute response of the vasculature to DPP-4 inhibition in humans. We recruited 38 patients with type 2 diabetes on stable background metformin therapy for a randomized, double-blind, placebo-controlled crossover trial of DPP-4 inhibition with sitagliptin (100 mg/day). Each treatment period was 8 weeks long separated by 4 weeks of washout. Endothelial function and plasma markers of endothelial activation (intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1)) were measured prior to and 2 hours following acute dosing of sitagliptin or placebo, as well as following 8 weeks of intervention with each pill. Thirty subjects completed the study and were included in analyses. Neither acute nor chronic sitagliptin therapy resulted in significant changes in vascular endothelial function. While post-acute sitagliptin ICAM-1 levels were lower than that post-chronic sitagliptin, the ICAM-1 concentration was not significantly different than pre-acute sitagliptin levels or levels measured in relationship to placebo. There were no significant changes in plasma VCAM-1 levels at any time point. Acute and chronic sitagliptin therapies have neutral effects on the vascular endothelium in the setting of metformin background therapy. In conclusion, our findings suggest DPP-4 inhibition has a neutral effect on cardiovascular risk in patients without a history of heart failure or renal insufficiency. TRIAL REGISTRATION NCT01859793.
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Affiliation(s)
- Michael E Widlansky
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Venkata K Puppala
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Tisha M Suboc
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mobin Malik
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Amberly Branum
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kara Signorelli
- 2 Medical College of Wisconsin School of Medicine, Milwaukee, WI, USA
| | - Jingli Wang
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Rong Ying
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Michael J Tanner
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Sudhi Tyagi
- 1 Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
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Vellecco V, Mitidieri E, Gargiulo A, Brancaleone V, Matassa D, Klein T, Esposito F, Cirino G, Bucci M. Vascular effects of linagliptin in non-obese diabetic mice are glucose-independent and involve positive modulation of the endothelial nitric oxide synthase (eNOS)/caveolin-1 (CAV-1) pathway. Diabetes Obes Metab 2016; 18:1236-1243. [PMID: 27460695 DOI: 10.1111/dom.12750] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/21/2016] [Accepted: 07/22/2016] [Indexed: 12/21/2022]
Abstract
AIM To test the effect of linagliptin in non-obese diabetic (NOD) mice, a murine model of type 1 diabetes, to unveil a possible direct cardiovascular action of dipeptidyl peptidase 4 (DPP-4) inhibitors beyond glycaemia control. METHODS NOD mice were grouped according to glycosuria levels as NODI: none; NODII: high; NODIII: severe. Linagliptin treatment was initiated once they reached NODII levels. Vascular reactivity was assessed ex vivo on aorta harvested from mice upon reaching NODIII level. In a separate set of experiments, the effect of linagliptin was tested directly in vitro on vessels harvested from untreated NODIII, glucagon-like peptide-1 (GLP-1) receptor knockout and soluble guanylyl cyclase-α1 knockout mice. Molecular and cellular studies were performed on endothelial and endothelial nitric oxide synthase (eNOS)-transfected cells. RESULTS In this ex vivo vascular study, endothelium-dependent vasorelaxation was ameliorated and eNOS/nitric oxide (NO)/soluble guanylyl cyclase (sGC) signalling was enhanced. In the in vitro vascular study, linagliptin exerted a direct vasodilating activity on vessels harvested from both normo- or hyperglycaemic mice. The effect was independent from GLP-1/GLP-1 receptor (GLP-1R) interaction and required eNOS/NO/sGC pathway activation. Molecular studies performed on endothelial cells show that linagliptin rescues eNOS from caveolin-1 (CAV-1)-binding in a calcium-independent manner. CONCLUSION Linagliptin, by interfering with the protein-protein interaction CAV-1/eNOS, led to an increased eNOS availability, thus enhancing NO production. This mechanism accounts for the vascular effect of linagliptin that is independent from glucose control and GLP-1/GLP-1R interaction.
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Affiliation(s)
- Valentina Vellecco
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Emma Mitidieri
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Antonella Gargiulo
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | | | - Danilo Matassa
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Thomas Klein
- Boehringer Ingelheim Pharma GmbH & Co. KG Cardio-metabolic Diseases, Ingelheim am Rhein, Germany
| | - Franca Esposito
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Giuseppe Cirino
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Mariarosaria Bucci
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
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Ott C, Kistner I, Keller M, Friedrich S, Willam C, Bramlage P, Schmieder RE. Effects of linagliptin on renal endothelial function in patients with type 2 diabetes: a randomised clinical trial. Diabetologia 2016; 59:2579-2587. [PMID: 27586249 DOI: 10.1007/s00125-016-4083-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/13/2016] [Indexed: 11/29/2022]
Abstract
AIMS/HYPOTHESIS Endothelial dysfunction predicts cardiovascular damage and renal involvement. Animal experiments and human studies indicate an increased nitric oxide (NO) activity and endothelial NO synthase (NOS) expression in the early stage of type 2 diabetes. The aim of the study was to assess the effect of linagliptin on the endothelial function of the renal vasculature. METHODS In this randomised, double-blind, parallel-group, investigator-initiated trial, 62 patients with type 2 diabetes were randomly assigned (by computer-generated random code) to receive linagliptin 5 mg (n = 30) or placebo (n = 32) for 4 weeks. The primary objective was to assess endothelial function of the renal vasculature, by constant-infusion input-clearance and urinary albumin/creatinine ratio (UACR), both before and after blockade of NOS with N G-monomethyl-L-arginine (L-NMMA). RESULTS Treatment with linagliptin for 4 weeks reduced fasting, postprandial blood glucose and HbA1c, although not significantly; no change occurred with placebo. Renal plasma flow (RPF) did not change after linagliptin or placebo. After 4 weeks the absolute change in RPF due to L-NMMA was smaller in the linagliptin group than in the placebo group (-46.8 ± 34 vs -65.1 ± 36 ml/min, p = 0.045), indicating a lower basal NO activity after treatment with linagliptin. Consistently, the response of UACR to L-NMMA increased in the placebo group (p = 0.059) but not in the linagliptin group (p = 0.276), pointing to an upregulation of NO activity in the placebo group. No clinically meaningful safety concerns were evident. CONCLUSIONS/INTERPRETATION Our data suggest that treatment with the dipeptidyl peptidase-4 inhibitor linagliptin for 4 weeks prevented the impairment of renal endothelial function due to hyperglycaemia in type 2 diabetes. TRIAL REGISTRATION ClinicalTrials.gov NCT01835678 FUNDING: : This study was funded by Boehringer Ingelheim.
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Affiliation(s)
- Christian Ott
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital, Ulmenweg 18, 91054, Erlangen, Germany
| | - Iris Kistner
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital, Ulmenweg 18, 91054, Erlangen, Germany
| | - Mirjam Keller
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital, Ulmenweg 18, 91054, Erlangen, Germany
| | - Stefanie Friedrich
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital, Ulmenweg 18, 91054, Erlangen, Germany
| | - Carsten Willam
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital, Ulmenweg 18, 91054, Erlangen, Germany
| | - Peter Bramlage
- Institute for Pharmacology and Preventive Medicine, Mahlow, Germany
| | - Roland E Schmieder
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital, Ulmenweg 18, 91054, Erlangen, Germany.
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Microvascular effects of the inhibition of dipeptidylpeptidase IV by linagliptin in nondiabetic hypertensive patients. J Hypertens 2016; 34:345-50. [PMID: 26599219 DOI: 10.1097/hjh.0000000000000776] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Recent studies suggest vascular benefits of dipeptidylpeptidase IV (DPP-IV) inhibition in patients with diabetes mellitus. Only little is known about potential vascular effects of DPP-IV inhibitors in nondiabetic individuals. The aim of this study was to investigate the effect of DPP-IV inhibition in a nondiabetic hypertensive population. METHOD This was a double-blinded, randomized, placebo-controlled, mechanistic study, comparing microvascular effects of the DPP-IV inhibitor linagliptin with placebo in nondiabetic individuals with a history of arterial hypertension. Twenty-one patients received 5 mg linagliptin (5 women; age 67.6 ± 6.0 years; mean ± SD), whereas 22 patients were randomized to placebo (5 women; age 64.8 ± 7.1 years). RESULTS At baseline, after 6 and 12 weeks, retinal microcirculation and arterial blood pressure profiles were assessed. Moreover, blood samples were taken for the measurement of HbA1c, asymmetric dimethylarginine, C-reactive peptide, cyclic guanosinmonophosphate, transforming growth factor beta (TGF-ß1) and cystatin C. Retinal capillary perfusion increased by 23.7 ± 10.3% (mean ± SEM; P < 0.05), retinal arterial flow by 7.6 ± 0.6 (P < 0.05) and the retinal hyperemic response by 290 ± 263% (P < 0.05) during treatment with linagliptin. No change in retinal blood flow was found in the placebo group. Although blood pressure declined in both groups, a significant decline in TGF-ß1 by 9.3 ± 4.5% (P < 0.05) could only be observed in the linagliptin group. No significant change in other laboratory parameters could be observed in both groups. CONCLUSION Our study suggests microvascular and antifibrotic effects of linagliptin in a nondiabetic, hypertensive population.
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Hardigan T, Abdul Y, Ergul A. Linagliptin reduces effects of ET-1 and TLR2-mediated cerebrovascular hyperreactivity in diabetes. Life Sci 2016; 159:90-96. [PMID: 26898123 PMCID: PMC4988948 DOI: 10.1016/j.lfs.2016.02.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 12/12/2022]
Abstract
AIMS The anti-hyperglycemic agent linagliptin, a dipeptidyl peptidase-4 inhibitor, has been shown to reduce inflammation and improve endothelial cell function. In this study, we hypothesized that DPP-IV inhibition with linagliptin would improve impaired cerebral blood flow in diabetic rats through improved insulin-induced cerebrovascular relaxation and reversal of pathological cerebrovascular remodeling that subsequently leads to improvement of cognitive function. MAIN METHODS Male type-2 diabetic Goto-Kakizaki (GK) and nondiabetic Wistar rats were treated with linagliptin, and ET-1 plasma levels and dose response curves to ET-1 (0.1-100nM) in basilar arteries were assessed. The impact of TLR2 antagonism on ET-1 mediated basilar contraction and endothelium-dependent relaxation to acetylcholine (ACh, 1nM-1M) in diabetic GK rats was examined with antibody directed against the TLR2 receptor (Santa Cruz, 5μg/mL). The expression of TLR2 in middle cerebral arteries (MCAs) from treated rats and in brain microvascular endothelial cells (BMVEC) treated with 100nM linagliptin was assessed. KEY FINDINGS Linagliptin lowered plasma ET-1 levels in diabetes, and reduced ET-1-induced vascular contraction. TLR2 antagonism in diabetic basilar arteries reduced ET-1-mediated cerebrovascular dysfunction and improved endothelium-dependent vasorelaxation. Linagliptin treatment in the BMVEC was able to reduce TLR2 expression in cells from both diabetic and nondiabetic rats. CONCLUSIONS These results suggest that inhibition of DPPIV using linagliptin improves the ET-1-mediated cerebrovascular dysfunction observed in diabetes through a reduction in ET-1 plasma levels and reduced cerebrovascular hyperreactivity. This effect is potentially a result of linagliptin causing a decrease in endothelial TLR2 expression and a subsequent increase in NO bioavailability.
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Affiliation(s)
- Trevor Hardigan
- Department of Physiology, Augusta University, Augusta, GA, United States
| | - Yasir Abdul
- Department of Physiology, Augusta University, Augusta, GA, United States
| | - Adviye Ergul
- Department of Physiology, Augusta University, Augusta, GA, United States; Charlie Norwood Veterans Administration Medical Center, Augusta, GA, United States.
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DPP-4 inhibitors in diabetic complications: role of DPP-4 beyond glucose control. Arch Pharm Res 2016; 39:1114-28. [PMID: 27502601 DOI: 10.1007/s12272-016-0813-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/04/2016] [Indexed: 12/12/2022]
Abstract
Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) are an emerging class of antidiabetic drugs that constitutes approximately fifty percent of the market share of the oral hypoglycemic drugs. Its mechanism of action for lowering blood glucose is essentially via inhibition of the rapid degradation of incretin hormones, such as glucagon-like peptide (GLP)-1 and gastric inhibitory polypeptide (GIP), thus the plasma concentration of GLP-1 increases, which promotes insulin secretion from the pancreatic β cells and suppresses glucagon secretion from the α cells. In addition to the direct actions on the pancreas, GLP-1 exhibits diverse actions on different tissues through its action on GLP-1 receptor, which is expressed ubiquitously. Moreover, DPP-4 has multiple substrates besides GLP-1 and GIP, including cytokines, chemokines, neuropeptides, and growth factors, which are involved in many pathophysiological conditions. Recently, it was suggested that DPP-4 is a new adipokine secreted from the adipose tissue, which plays an important role in the regulation of the endocrine function in obesity-associated type 2 diabetes. Consequently, DPP-4 inhibitors have been reported to exhibit cytoprotective functions against various diabetic complications affecting the liver, heart, kidneys, retina, and neurons. This review outlines the current understanding of the effect of DPP-4 inhibitors on the complications associated with type 2 diabetes, such as liver steatosis and inflammation, dysfunction of the adipose tissue and pancreas, cardiovascular diseases, nephropathy, and neuropathy in preclinical and clinical studies.
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Hardigan T, Yasir A, Abdelsaid M, Coucha M, El-Shaffey S, Li W, Johnson MH, Ergul A. Linagliptin treatment improves cerebrovascular function and remodeling and restores reduced cerebral perfusion in Type 2 diabetes. Am J Physiol Regul Integr Comp Physiol 2016; 311:R466-77. [PMID: 27357799 DOI: 10.1152/ajpregu.00057.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/24/2016] [Indexed: 12/20/2022]
Abstract
The antihyperglycemic agent linagliptin, a dipeptidyl peptidase-4 (DPP-IV) inhibitor, has been shown to reduce inflammation and improve endothelial cell function. In this study, we hypothesized that DPP-IV inhibition with linagliptin would improve impaired cerebral perfusion in diabetic rats, as well as improve insulin-induced cerebrovascular relaxation and reverse pathological cerebrovascular remodeling. We further postulated that these changes would lead to a subsequent improvement of cognitive function. Male Type-2 diabetic and nondiabetic Goto-Kakizaki rats were treated with linagliptin for 4 wk, and blood glucose and DPP-IV plasma levels were assessed. Cerebral perfusion was assessed after treatment using laser-Doppler imaging, and dose response to insulin (10(-13) M-10(-6) M) in middle cerebral arteries was tested on a pressurized arteriograph. The impact of DPP-IV inhibition on diabetic cerebrovascular remodeling was assessed over a physiologically relevant pressure range, and changes in short-term hippocampus-dependent learning were observed using a novel object recognition test. Linagliptin lowered DPP-IV activity but did not change blood glucose or insulin levels in diabetes. Insulin-mediated vascular relaxation and cerebral perfusion were improved in the diabetic rats with linagliptin treatment. Indices of diabetic vascular remodeling, such as increased cross-sectional area, media thickness, and wall-to-lumen ratio, were also ameliorated; however, improvements in short-term hippocampal-dependent learning were not observed. The present study provides evidence that linagliptin treatment improves cerebrovascular dysfunction and remodeling in a Type 2 model of diabetes independent of glycemic control. This has important implications in diabetic patients who are predisposed to the development of cerebrovascular complications, such as stroke and cognitive impairment.
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Affiliation(s)
- Trevor Hardigan
- Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Abdul Yasir
- Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Mohammed Abdelsaid
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Maha Coucha
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Sally El-Shaffey
- Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Weiguo Li
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Maribeth H Johnson
- Department of Biostatistics, The Graduate School at Augusta University, Augusta, Georgia
| | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
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Li X, Li J, Li Z, Sang Y, Niu Y, Zhang Q, Ding H, Yin S. Fucoidan from Undaria pinnatifida prevents vascular dysfunction through PI3K/Akt/eNOS-dependent mechanisms in the l-NAME-induced hypertensive rat model. Food Funct 2016; 7:2398-408. [PMID: 27153123 DOI: 10.1039/c6fo00288a] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Despite major scientific advances in its prevention, treatment and care, hypertension remains a serious condition that might lead to long-term complications such as heart disease and stroke. The great majority of forms of hypertension eventually result from an increased vasomotor tone activity that is regulated by endothelial NOS (eNOS) in vascular endothelium. Here, we examined the effect of fucoidan on eNOS activation in human umbilical vein endothelial cells (HUVECs). We also examined the effects of functional components of Undaria pinnatifida fucoidan on blood pressure and vascular function in eNOS inhibition-induced hypertensive rats in vivo. Our results suggest that fucoidan increased nitric oxide production by activating eNOS and Akt phosphorylation, which could be impaired by Akt or eNOS inhibitors. In the hypertensive rat model, treatment of fucoidan resulted in potent and persistent reduction of high blood pressure (BP) even after drug withdrawal. Our results showed that the mechanisms might involve protection against vascular structure damage, enhanced endothelium-independent vascular function and inhibition of abnormal proliferation of smooth muscle cells, which are mediated by the Akt-eNOS signaling pathway. Moreover, fucoidan treatment reduced the vascular inflammation and oxidative stress control caused by iNOS expression. Together, these results support a putative role of fucoidan in hypertension prevention and treatment.
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Affiliation(s)
- Xiaofei Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, China.
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Bonora E, Cigolini M. DPP-4 inhibitors and cardiovascular disease in type 2 diabetes mellitus. Expectations, observations and perspectives. Nutr Metab Cardiovasc Dis 2016; 26:273-284. [PMID: 27038847 DOI: 10.1016/j.numecd.2016.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 03/04/2016] [Accepted: 03/04/2016] [Indexed: 02/06/2023]
Abstract
AIMS Cardiovascular disease (CVD) is the greatest burden of type 2 diabetes mellitus (T2DM) in terms of morbility, mortality and costs for individuals and societies. Therefore, its prevention is a major goal in diabetes care. Optimal treatment of hyperglycemia is certainly instrumental to CVD prevention. Optimal treatment means both establishing the most appropriate glycemic target for the given individual and selecting the medication(s) with the most favourable benefit/safety ratio. CVD safety, if not a clear CVD benefit, is certainly required for all antidiabetic agents. Dipeptidyl-peptidase-4 (DPP-4) inhibitors are among the classes of antidiabetic agents most recently made available for diabetes care. A major question to be addressed is the effect of these compounds on CVD. Expectations were high for their mechanism of action, which targets also post-prandial glucose and minimize hypoglycemia risk, thereby providing a sort of global glucose control, and for some potentially beneficial extra-glycemic effects. This article reviews the existing literature on this issue. DATA SYNTHESIS Data published so far document that DPP-4 inhibitors have a wide spectrum of glycemic and extra-glycemic effects potentially reducing the risk of CVD as well as favourable effects on intermediate or surrogate CVD endpoints. These data heralded a better CVD outcome. Accordingly, pooling CVD safety data from phase 3 and 4 studies conducted with DPP-4 inhibitors suggested that their use might translate into a better CVD outcome. Data from three CVD outcome RCTs with alogliptin, saxagliptin and sitagliptin documented no harm but did not show any benefit on major CVD events. A modest but significant increased risk of hospitalization for heart failure was observed with saxagliptin and with alogliptin (only in subjects with no history of heart failure before randomization) but not with sitagliptin. A study currently in progress with linagliptin will provide further insights in the issue of CVD safety and benefit. CONCLUSIONS It should be considered that most alternative oral antidiabetic agents generally do not possess a better CVD risk profile than DPP-4 inhibitors and that some of them, indeed, should be used with caution because of potentially adverse effects on heart and vasculature. Overall, the selection of antidiabetic agent(s) with the most favourable CVD profile is mandatory but still challenging in diabetes care.
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Affiliation(s)
- Enzo Bonora
- Endocrinology, Diabetes and Metabolism, University and Hospital Trust of Verona, Verona, Italy.
| | - Massimo Cigolini
- Endocrinology, Diabetes and Metabolism, University and Hospital Trust of Verona, Verona, Italy
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Duvnjak L, Blaslov K. Dipeptidyl peptidase-4 inhibitors improve arterial stiffness, blood pressure, lipid profile and inflammation parameters in patients with type 2 diabetes mellitus. Diabetol Metab Syndr 2016; 8:26. [PMID: 27006706 PMCID: PMC4802883 DOI: 10.1186/s13098-016-0144-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/09/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND This uncontrolled open label study evaluated the effect of dipeptidyl peptidase-4 inhibitors (DPP-4i): sitagliptin and vildagliptin on augmentation index standardized for 75 beats per minute (cAiX@75), blood pressure (BP), lipid profile and high-sensitivity C-reactive protein (hsCRP) in patients with type 2 diabetes mellitus (T2DM). METHODS Fifty-one well-regulated T2DM patients were randomly assigned to either sitagliptin or vildagliptin (100 mg/day) for 3 months continuing their previous treatment. Lipid profile, cAiX@75, hsCRP, glycated hemoglobin (HbA1c) were measured at baseline at 4, 8 and 12th week were accessed. cAiX@75 and pulse wave velocity (PWV) were determined by SphygmoCor device. RESULTS Following DPP-4 treatment there was a significant reduction in total serum cholesterol (5.18 vs 4.62 mmol/L), low-density lipoprotein (2.89 vs 2.54 mmol/L), hsCRP (3.21 vs 1.95 mg/L), cAiX@75 (24.5 vs 22.3) and central systolic BP (131.8 vs 119.5 mmHg). The sitagliptin treated group reached cAiX@75 reduction earlier in the study period while neither sitagliptin or vildagliptin use resulted in the significant HbA1c reduction. CONCLUSION The treatment with DPP-4i: sitagliptin and vildagliptin provides favorable metabolic and vascular effects beyond glucose-control. Further studies are required to elucidate their implication in metabolic pathways.
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Affiliation(s)
- Lea Duvnjak
- />Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic diseases, Merkur University hospital, Dugi dol 4a, Zagreb, Croatia
- />School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Kristina Blaslov
- />Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic diseases, Merkur University hospital, Dugi dol 4a, Zagreb, Croatia
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Yasir A, Hardigan T, Ergul A. Diabetes-mediated middle cerebral artery remodeling is restored by linagliptin: Interaction with the vascular smooth muscle cell endothelin system. Life Sci 2016; 159:76-82. [PMID: 26944436 DOI: 10.1016/j.lfs.2016.02.096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 02/25/2016] [Accepted: 02/29/2016] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Endothelin-1 (ET-1) mediates cerebrovascular remodeling in vascular smooth muscle layer of the middle cerebral arteries (MCA) in type-2 diabetic Goto-Kakizaki (GK) rats. While metformin, oral glucose lowering agent, prevent/restores vascular remodeling and reduce systemic and local ET-1 levels whether this effect was specific to metformin remained unknown. Our working hypotheses were 1) linagliptin, a DPP-IV inhibitor, can reverse diabetes-mediated cerebrovascular remodeling and this is associated with decreased ET-1, and 2) linagliptin prevents the high glucose induced increase in ET-1 and ET receptors in brain vascular smooth muscle cells (bVSMCs). METHODS Diabetic and non-diabetic GK rats were treated with linagliptin (4weeks). MCAs were fixed in buffered 4% paraformaldehyde and used for morphometry. Human bVSMCs incubated in normal glucose (5.5mM)/high glucose (25mM) conditions were treated with the linagliptin (100nM; 24h). ET-1 secretion and ET receptors were measured in media and cell lysate respectively. Immunostaining was performed for ET-A and ET-B receptor. ET receptors were also measured in cells treated with ET-1 (100nM) and linagliptin. RESULTS Linagliptin treatment regressed vascular remodeling of MCAs in diabetic animals but had no effect on blood glucose. bVSMCs in normal/high glucose condition did not show any significant difference in ET-1 secretion or ET-A and ET-B receptor expression. ET-1 treatment in high glucose condition significantly increased the ET-A receptors and this effect was inhibited by linagliptin. CONCLUSIONS Linagliptin is effective in reversing established pathological cerebrovascular remodeling associated with diabetes. Attenuation of the ET system could be a pleiotropic effect of linagliptin that provides vascular protection.
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Affiliation(s)
- Abdul Yasir
- Charlie Norwood Veterans Administration Medical Center, Augusta University, Augusta, Georgia, United States; Department of Physiology, Augusta University, Augusta, Georgia, United States
| | - Trevor Hardigan
- Department of Physiology, Augusta University, Augusta, Georgia, United States
| | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta University, Augusta, Georgia, United States; Department of Physiology, Augusta University, Augusta, Georgia, United States.
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Poudyal H. Mechanisms for the cardiovascular effects of glucagon-like peptide-1. Acta Physiol (Oxf) 2016; 216:277-313. [PMID: 26384481 DOI: 10.1111/apha.12604] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/25/2015] [Accepted: 09/10/2015] [Indexed: 12/16/2022]
Abstract
Over the past three decades, at least 10 hormones secreted by the enteroendocrine cells have been discovered, which directly affect the cardiovascular system through their innate receptors expressed in the heart and blood vessels or through a neural mechanism. Glucagon-like peptide-1 (GLP-1), an important incretin, is perhaps best studied of these gut-derived hormones with important cardiovascular effects. In this review, I have discussed the mechanism of GLP-1 release from the enteroendocrine L-cells and its physiological effects on the cardiovascular system. Current evidence suggests that GLP-1 has positive inotropic and chronotropic effects on the heart and may be important in preserving left ventricular structure and function by direct and indirect mechanisms. The direct effects of GLP-1 in the heart may be mediated through GLP-1R expressed in atria as well as arteries and arterioles in the left ventricle and mainly involve in the activation of multiple pro-survival kinases and enhanced energy utilization. There is also good evidence to support the involvement of a second, yet to be identified, GLP-1 receptor. Further, GLP-1(9-36)amide, which was previously thought to be the inactive metabolite of the active GLP-1(7-36)amide, may also have direct cardioprotective effects. GLP-1's action on GLP-1R expressed in the central nervous system, kidney, vasculature and the pancreas may indirectly contribute to its cardioprotective effects.
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Affiliation(s)
- H. Poudyal
- Department of Diabetes, Endocrinology and Nutrition; Graduate School of Medicine and Hakubi Centre for Advanced Research; Kyoto University; Kyoto Japan
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Kimura S, Inoguchi T, Yamasaki T, Yamato M, Ide M, Sonoda N, Yamada K, Takayanagi R. A novel DPP-4 inhibitor teneligliptin scavenges hydroxyl radicals: In vitro study evaluated by electron spin resonance spectroscopy and in vivo study using DPP-4 deficient rats. Metabolism 2016; 65:138-45. [PMID: 26892525 DOI: 10.1016/j.metabol.2015.10.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/08/2015] [Accepted: 10/27/2015] [Indexed: 10/22/2022]
Abstract
AIMS Recently various dipeptidyl peptidase-4 (DPP-4) inhibitors have emerged because of their high effectiveness and safety. In spite of their common effect of DPP-4 inhibition, the chemical structures are diverse. Here we show that the structure of teneligliptin, a novel DPP-4 inhibitor, has a scavenging activity on hydroxyl radical (·OH). METHODS ·OH and superoxide (O2(-)) were detected by electron spin resonance (ESR) spectroscopy. ·OH and O2(-) were generated in vitro by the Fenton reaction and a hypoxanthine-xanthine oxidase system, respectively. The level of free radicals was estimated from the ESR signal intensity. The product via teneligliptin and ·OH reaction was identified by thin layer chromatography and mass spectrometry analysis. In vivo effect was also evaluated using DPP-4 deficient rats with streptozotocin-induced diabetes. RESULTS ESR spectroscopy analysis showed that teneligliptin did not scavenge O2(-), but scavenged ·OH in a dose dependent manner. Its activity was greater than that of glutathione. The reaction product appeared to have an oxygen-atom added structure to that of teneligliptin, which was identical to the most abundant metabolite of teneligliptin in human plasma. Furthermore, using DPP-4 deficient rat, teneligliptin did not affect plasma glucose levels or body weight, but normalized increased levels of 8-hydroxy-2'-deoxyguanosine in urine, kidney and aorta of diabetic rats, supporting that teneligliptin may have a ·OH scavenging activity in vivo independently of DPP-4 inhibition. CONCLUSIONS Teneligliptin is not only effective as DPP-4 inhibitor, but may also be beneficial as ·OH scavenger, which may be useful in the prevention of diabetic complications.
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Affiliation(s)
- Shinichiro Kimura
- The Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toyoshi Inoguchi
- The Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; The Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan.
| | - Toshihide Yamasaki
- The Department of Bio-functional Science, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Mayumi Yamato
- The Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan
| | - Makoto Ide
- The Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Noriyuki Sonoda
- The Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; The Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan
| | - Kenichi Yamada
- The Department of Bio-functional Science, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Ryoichi Takayanagi
- The Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Abstract
The incretin-based therapies, dipeptidyl peptidase-4 (DPP4) inhibitors and glucagon-like peptide-1 (GLP-1) analogs, are important new classes of therapy for type 2 diabetes mellitus (T2DM). These agents prolong the action of the incretin hormones, GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), by inhibiting their breakdown. The incretin hormones improve glycemic control in T2DM by increasing insulin secretion and suppressing glucagon levels. The cardiovascular (CV) effects of the incretin-based therapies have been of substantial interest since 2008, when the US Food and Drug Administration began to require that all new therapies for diabetes undergo rigorous assessment of CV safety through large-scale CV outcome trials. This article reviews the most recent CV outcome trials of the DPP-4 inhibitors (SAVOR-TIMI 53, EXAMINE, and TECOS) as evidence that the incretin-based therapies have acceptable CV safety profiles for patients with T2DM. The studies differ with regard to patient population, trial duration, and heart failure outcomes but show similar findings for CV death, nonfatal myocardial infarction, and stroke, as well as hospitalization for unstable angina.
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Affiliation(s)
- William B. White
- Division of Hypertension and Clinical Pharmacology, Calhoun Cardiology Center, University of Connecticut School of Medicine, Farmington, Connecticut 06032
| | - William L. Baker
- University of Connecticut School of Pharmacy, Storrs, Connecticut 06269
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Zhang X, Zhang Z, Li M, Li G, Liu T. Potential role of dipeptidyl peptidase-4 inhibitors in atrial fibrillation. Int J Cardiol 2016; 207:46-7. [PMID: 26788822 DOI: 10.1016/j.ijcard.2016.01.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 01/05/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Xiaowei Zhang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China
| | - Zhiwei Zhang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China
| | - Mingzhen Li
- Key Laboratory of Hormones and Development (Ministry of Health), Department of Diabetes and Gout, Metabolic Disease Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, People's Republic of China
| | - Guangping Li
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, People's Republic of China.
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Jung E, Kim J, Kim CS, Kim SH, Cho MH. Gemigliptin, a dipeptidyl peptidase-4 inhibitor, inhibits retinal pericyte injury in db/db mice and retinal neovascularization in mice with ischemic retinopathy. Biochim Biophys Acta Mol Basis Dis 2015; 1852:2618-29. [DOI: 10.1016/j.bbadis.2015.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/04/2015] [Accepted: 09/16/2015] [Indexed: 12/21/2022]
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Remm F, Franz WM, Brenner C. Gliptins and their target dipeptidyl peptidase 4: implications for the treatment of vascular disease. EUROPEAN HEART JOURNAL. CARDIOVASCULAR PHARMACOTHERAPY 2015; 2:185-93. [PMID: 27533760 DOI: 10.1093/ehjcvp/pvv044] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/26/2015] [Indexed: 12/31/2022]
Abstract
Gliptins are accepted as a standard therapy for diabetes mellitus today. By inhibition of the enzyme dipeptidyl peptidase 4 (DPP4), gliptins prolong the GLP1-dependent insulin secretion in the pancreatic β-cells and thus support physiological blood glucose control. Various studies have now raised hope for an additional protective effect of pharmacological DPP4 inhibition in vascular diseases. Besides GLP1, especially, the inhibition of SDF1 cleavage has been shown to depict a relevant mechanism to enhance endothelial regeneration and reduce atherosclerosis progression via the SDF1-CXCR4 axis. Furthermore, several clinical trials have now shown an excellent safety profile of gliptin therapy in cardiovascular risk patients. In this review, we give a comprehensive overview on DPP4-dependent vascular functions and pathophysiological mechanisms with a detailed discussion of the underlying molecular mechanisms. We further analyse the role of pharmacological DPP4 inhibitors and their potential therapeutic impact on endothelial function and regeneration besides their effect during atherosclerosis development. Finally, we discuss presently available data from in vitro and in vivo studies with respect to the results of the recent clinical trials in diabetic and non-diabetic patients.
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Affiliation(s)
- Friederike Remm
- Department of Internal Medicine III, Medical University of Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
| | - Wolfgang-Michael Franz
- Department of Internal Medicine III, Medical University of Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
| | - Christoph Brenner
- Department of Internal Medicine III, Medical University of Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
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Di-peptidyl peptidase-4 inhibitor sitagliptin protects vascular function in metabolic syndrome: possible role of epigenetic regulation. Mol Biol Rep 2015; 41:4853-63. [PMID: 24838371 DOI: 10.1007/s11033-014-3392-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Metabolic syndrome (MetS) is a complex medical disorder characterized by insulin resistance, hypertension, and high risk of coronary disease and stroke. Microvascular rarefaction and endothelial dysfunction have also been linked with MetS, and recent evidence from clinical studies supports the efficacy of incretin-based antidiabetic therapies for vascular protection in diabetes. Previous studies pointed out the importance of dipeptidyl peptidase-4 (DPP-4) inhibition in endothelial cells due to getting protection against metabolic pathologies. We therefore aimed to investigate the acute effects of a DPP-4 inhibitor, sitagliptin, on vascular function in rats with high-sucrose diet-induced MetS. In order to elucidate the mechanisms implicated in the effects of DPP-4 inhibition, we tested the involvement of NO pathway and epigenetic regulation in the MetS. Acute use of sitagliptin protects the vascular function in the rats with MetS in part due to NO pathway via restoring the depressed aortic relaxation responses mediated by receptors. Application of sitagliptin enhanced the depressed phosphorylation levels of both the endothelial NO synthase and the apoptotic status of protein kinase B, known as Akt, in endothelium-intact thoracic aorta from rats with MetS. One-hour application of sitagliptin on aortic rings from rats with MetS also induced remarkable histon posttranslational modifications such as increased expression of H3K27Me3, but not of H3K27Me2, resulting in an accumulation of the H3K27Me3. Our findings suggest that, in addition to its well-known hypoglycemic action, sitagliptin may also have beneficial effects on hyperglycemia-induced vascular changes in an endotheium-dependent manner. These present results with sitagliptin aside from the glycaemic control, may demonstrate its important role in the treatment of patients with MetS.
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Singh TP, Vangaveti VN, Malabu UH. Dipeptidyl peptidase-4 inhibitors and their potential role in the management of atherosclerosis--A review. Diabetes Metab Syndr 2015; 9:223-229. [PMID: 26067782 DOI: 10.1016/j.dsx.2015.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Dipeptidyl peptidase-4 (DPP-4) inhibitors are a relatively new class of anti-diabetic drugs that have therapeutic potential in the management of atherosclerosis. Of the numerous DPP-4 inhibitors in clinical practice no studies have been conducted to compare their anti-atherosclerotic effects despite growing evidence of their usefulness in the high risk population. OBJECTIVE The aim of the study was to review the anti-athero-thrombotic effects of DPP-4 inhibitors in atherosclerotic diseases. METHOD A literature search was conducted on MEDLINE and the COCHRANE Library using the terms "DPP-4 Inhibitors", "atherosclerosis", "GLP", "inflammation", "cytokines", "stroke", "ischaemic heart disease", "hypertension" and "peripheral vascular disease". A mathematical model devised by us was used to derive and compare the anti-inflammatory effects of the DPP-4 inhibitors using protective score [PS]. Data was analysed for alogliptin, linagliptin, saxagliptin, sitagliptin, and vildagliptin. RESULTS Sixty two published studies collected in the search were assessed for relevance to this study. Sitagliptin had the highest PS [n=5] while linagliptin and saxagliptin yielded the lowest PS [n=1]. This comparison and scoring system was limited to the data collected; which did not investigate for all athero-thrombotic factors selected in this study. CONCLUSION The findings suggest potential usefulness of DPP-4 in atherosclerotic diseases. It also reflected a possible superiority of sitagliptin over the other DPP-4 inhibitors in the management of atherosclerosis. Further investigations are required to establish specific inflammatory cytokines influenced by the DPP-4 inhibitors and to elucidate their clinical application in athero-thrombotic disease.
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Affiliation(s)
- Tejas P Singh
- Translational Research on Endocrinology and Diabetes [TREAD], School of Medicine and Dentistry, James Cook University Townsville, Australia
| | - Venkat N Vangaveti
- Translational Research on Endocrinology and Diabetes [TREAD], School of Medicine and Dentistry, James Cook University Townsville, Australia
| | - Usman H Malabu
- Translational Research on Endocrinology and Diabetes [TREAD], School of Medicine and Dentistry, James Cook University Townsville, Australia.
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Zhong J, Rajagopalan S. Dipeptidyl Peptidase-4 Regulation of SDF-1/CXCR4 Axis: Implications for Cardiovascular Disease. Front Immunol 2015; 6:477. [PMID: 26441982 PMCID: PMC4585326 DOI: 10.3389/fimmu.2015.00477] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/03/2015] [Indexed: 12/19/2022] Open
Abstract
Dipeptidyl peptidase-4 (DPP4) is a ubiquitously expressed protease that regulates diverse number of physiological functions. As a dipeptidase, it exerts its catalytic effects on proteins/peptides with proline, alanine, or serine in the penultimate (P1) amino acid residue from the amino terminus. The evidence to date supports an important effect of DPP4 in catalytic cleavage of incretin peptides and this perhaps represents the main mechanism by which DPP4 inhibition improves glycemic control. DPP4 also plays an important role in the degradation of multiple chemokines of which stromal cell-derived factor-1 (SDF-1, also known as CXCL12) is perhaps an increasingly recognized target, given its importance in processes, such as hematopoiesis, angiogenesis, and stem cell homing. In the current review, we will summarize the importance of DPP4-mediated enzymatic processing of cytokines/chemokines with an emphasis on SDF-1 and resultant implications for cardiovascular physiology and disease.
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Affiliation(s)
- Jixin Zhong
- Division of Cardiovascular Medicine, University of Maryland, Baltimore , Baltimore, MD , USA
| | - Sanjay Rajagopalan
- Division of Cardiovascular Medicine, University of Maryland, Baltimore , Baltimore, MD , USA
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Sanchez RA, Sanabria H, Santos CDL, Ramirez AJ. Incretins and selective renal sodium-glucose co-transporter 2 inhibitors in hypertension and coronary heart disease. World J Diabetes 2015; 6:1186-1197. [PMID: 26380062 PMCID: PMC4564814 DOI: 10.4239/wjd.v6.i11.1186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 01/29/2015] [Accepted: 08/31/2015] [Indexed: 02/05/2023] Open
Abstract
Hyperglycemia is associated with an increased risk of cardiovascular disease, and the consequences of intensive therapy may depend on the mechanism of the anti-diabetic agent(s) used to achieve a tight control. In animal models, stable analogues of glucagon-like peptide-1 (GLP-1) were able to reduce body weight and blood pressure and also had favorable effects on ischemia following coronary reperfusion. In a similar way, dipeptidyl peptidase IV (DPP-IV) showed to have favorable effects in animal models of ischemia/reperfusion. This could be due to the fact that DPP-IV inhibitors were able to prevent the breakdown of GLP-1 and glucose-dependent insulinotropic polypeptide, but they also decreased the degradation of several vasoactive peptides. Preclinical data for GLP-1, its derivatives and inhibitors of the DPP-IV enzyme degradation suggests that these agents may be able to, besides controlling glycaemia, induce cardio-protective and vasodilator effects. Notwithstanding the many favorable cardiovascular effects of GLP-1/incretins reported in different studies, many questions remain unanswered due the limited number of studies in human beings that aim to examine the effects of GLP-1 on cardiovascular endpoints. For this reason, long-term trials searching for positive cardiovascular effects are now in process, such as the CAROLINA and CARMELINA trials, which are supported by small pilot studies performed in humans (and many more animal studies) with incretin-based therapies. On the other hand, selective renal sodium-glucose co-transporter 2 inhibitors were also evaluated in the prevention of cardiovascular outcomes in type 2 diabetes. However, it is quite early to draw conclusions, since data on cardiovascular outcomes and cardiovascular death are limited and long-term studies are still ongoing. In this review, we will analyze the mechanisms underlying the cardiovascular effects of incretins and, at the same time, we will present a critical position about the real value of these compounds in the cardiovascular system and its protection.
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Salim HM, Fukuda D, Higashikuni Y, Tanaka K, Hirata Y, Yagi S, Soeki T, Shimabukuro M, Sata M. Dipeptidyl peptidase-4 inhibitor, linagliptin, ameliorates endothelial dysfunction and atherogenesis in normoglycemic apolipoprotein-E deficient mice. Vascul Pharmacol 2015; 79:16-23. [PMID: 26277250 DOI: 10.1016/j.vph.2015.08.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 07/31/2015] [Accepted: 08/11/2015] [Indexed: 12/25/2022]
Abstract
BACKGROUND Dipeptidyl peptidase-4 (DPP-4) inhibitors have vasoprotective effects. This study investigated whether a recently approved DPP-4 inhibitor, linagliptin (Lina), suppresses atherogenesis in non-diabetic apolipoprotein-E deficient (ApoE(-/-)) mice, and examined its effects on endothelial function. METHODS AND RESULTS Lina (10mg/kg/day) was administered orally to ApoE(-/-) mice for 20 weeks. Lina reduced atherogenesis without alteration of metabolic parameters including blood glucose level compared with control (P<0.05). Results of immunohistochemical analyses and quantitative RT-PCR demonstrated that Lina significantly decreased inflammatory molecule expression and macrophage infiltration in the atherosclerotic aorta. Lina administration to ApoE(-/-) mice for 9 weeks ameliorated endothelium-dependent vasodilation compared with that in untreated mice. Plasma active glucagon-like peptide-1 (GLP-1) level was significantly higher in the treated group (P<0.05). Exendin-4 (Ex-4), a GLP-1 analog, ameliorated endothelium-dependent vasodilation impaired by palmitic acid (PA) in wild-type mouse aortic segments. Ex-4 promoted phosphorylation of eNOS(Ser1177) and Akt, both of which were abrogated by PA, in human umbilical vein endothelial cells. In addition, Lina administration to ApoE(-/-) mice decreased oxidative stress, as determined by urinary 8-OHdG secretion and NADPH oxidase subunit expression in the abdominal aorta. CONCLUSION Lina inhibited atherogenesis in non-diabetic ApoE(-/-) mice. Amelioration of endothelial dysfunction associated with a reduction of oxidative stress by GLP-1 contributes to the atheroprotective effects of Lina.
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Affiliation(s)
- Hotimah Masdan Salim
- Department of Cardiovascular Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan
| | - Daiju Fukuda
- Department of Cardiovascular Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan.
| | | | - Kimie Tanaka
- Division for Health Service Promotion, The University of Tokyo, Japan
| | - Yoichiro Hirata
- Department of Pediatrics, The University of Tokyo Hospital, Japan
| | - Shusuke Yagi
- Department of Cardiovascular Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan
| | - Takeshi Soeki
- Department of Cardiovascular Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan
| | - Michio Shimabukuro
- Department of Cardio-Diabetes Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan
| | - Masataka Sata
- Department of Cardiovascular Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Japan
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77
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Steven S, Münzel T, Daiber A. Exploiting the Pleiotropic Antioxidant Effects of Established Drugs in Cardiovascular Disease. Int J Mol Sci 2015; 16:18185-223. [PMID: 26251902 PMCID: PMC4581241 DOI: 10.3390/ijms160818185] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 07/20/2015] [Accepted: 07/27/2015] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular disease is a leading cause of death and reduced quality of life worldwide. Arterial vessels are a primary target for endothelial dysfunction and atherosclerosis, which is accompanied or even driven by increased oxidative stress. Recent research in this field identified different sources of reactive oxygen and nitrogen species contributing to the pathogenesis of endothelial dysfunction. According to lessons from the past, improvement of endothelial function and prevention of cardiovascular disease by systemic, unspecific, oral antioxidant therapy are obviously too simplistic an approach. Source- and cell organelle-specific antioxidants as well as activators of intrinsic antioxidant defense systems might be more promising. Since basic research demonstrated the contribution of different inflammatory cells to vascular oxidative stress and clinical trials identified chronic inflammatory disorders as risk factors for cardiovascular events, atherosclerosis and cardiovascular disease are closely associated with inflammation. Therefore, modulation of the inflammatory response is a new and promising approach in the therapy of cardiovascular disease. Classical anti-inflammatory therapeutic compounds, but also established drugs with pleiotropic immunomodulatory abilities, demonstrated protective effects in various models of cardiovascular disease. However, results from ongoing clinical trials are needed to further evaluate the value of immunomodulation for the treatment of cardiovascular disease.
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Affiliation(s)
- Sebastian Steven
- Medical Clinic, University Medical Center of the Johannes Gutenberg-University, Mainz 55131, Germany.
- Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg-University, Mainz 55131, Germany.
| | - Thomas Münzel
- Medical Clinic, University Medical Center of the Johannes Gutenberg-University, Mainz 55131, Germany.
| | - Andreas Daiber
- Medical Clinic, University Medical Center of the Johannes Gutenberg-University, Mainz 55131, Germany.
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78
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Fadini GP, Albiero M, Avogaro A. Direct effects of DPP-4 inhibition on the vasculature. Reconciling basic evidence with lack of clinical evidence. Vascul Pharmacol 2015; 73:1-3. [PMID: 26254108 DOI: 10.1016/j.vph.2015.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/03/2015] [Indexed: 01/04/2023]
Abstract
Diabetes is burdened by macrovascular and microvascular complications that collectively reduce life expectancy. As the ultimate goal of diabetes treatment is to prevent excess morbidity and mortality associated with its complications, the interest on cardiovascular effects of glucose lowering medications is high. Dipeptidyl peptidase-4 inhibitors (DPP-4i) lower blood glucose by protecting the incretin hormone glucagon-like peptide-1 (GLP-1) from enzymatic degradation, thereby restoring meal-stimulated insulin release. DPP-4 has several non-incretin substrates, including cytokines, chemokines, and neurohormones, which can exert favourable, but also unpredictable, vascular effects, once they are stabilized by DPP-4i. Choi et al. now provide additional evidence that DPP-4i counteracts vascular smooth muscle cell proliferation and migration, resulting in an attenuation of neointimal hyperplasia. Though several other in vitro, preclinical, and preliminary clinical studies on surrogate end-points suggest that DPP-4i can exert similar direct vasculoprotective actions, results of placebo-controlled phase IV trials have so far shown no reduction cardiovascular endpoints by DPP-4i. In this commentary, we put DPP-4 pleiotropy and complexity into context, trying to reconcile why results from basic science have not yet translated into clinical evidence of cardiovascular protection.
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Affiliation(s)
- Gian Paolo Fadini
- Department of Medicine, University of Padova, 35128 Padova, Italy; Venetian Institute of Molecular Medicine, 35128 Padova, Italy.
| | - Mattia Albiero
- Department of Medicine, University of Padova, 35128 Padova, Italy; Venetian Institute of Molecular Medicine, 35128 Padova, Italy
| | - Angelo Avogaro
- Department of Medicine, University of Padova, 35128 Padova, Italy; Venetian Institute of Molecular Medicine, 35128 Padova, Italy
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79
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Aroor AR, Sowers JR, Jia G, DeMarco VG. Pleiotropic effects of the dipeptidylpeptidase-4 inhibitors on the cardiovascular system. Am J Physiol Heart Circ Physiol 2015; 307:H477-92. [PMID: 24929856 DOI: 10.1152/ajpheart.00209.2014] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dipeptidylpeptidase-4 (DPP-4) is a ubiquitously expressed transmembrane protein that removes NH2-terminal dipeptides from various substrate hormones, chemokines, neuropeptides, and growth factors. Two known substrates of DPP-4 include the incretin hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide, which are secreted by enteroendocrine cells in response to postprandial hyperglycemia and account for 60–70% of postprandial insulin secretion. DPP-4 inhibitors (DPP-4i) block degradation of GLP-1 and gastric inhibitory peptide, extend their insulinotropic effect, and improve glycemia. Since 2006, several DPP-4i have become available for treatment of type 2 diabetes mellitus. Clinical trials confirm that DPP-4i raises GLP-1 levels in plasma and improves glycemia with very low risk for hypoglycemia and other side effects. Recent studies also suggest that DPP-4i confers cardiovascular and kidney protection, beyond glycemic control, which may reduce the risk for further development of the multiple comorbidities associated with obesity/type 2 diabetes mellitus, including hypertension and cardiovascular disease (CVD) and kidney disease. The notion that DPP-4i may improve CVD outcomes by mechanisms beyond glycemic control is due to both GLP-1-dependent and GLP-1-independent effects. The CVD protective effects by DPP-4i result from multiple factors including insulin resistance, oxidative stress, dyslipidemia, adipose tissue dysfunction, dysfunctional immunity, and antiapoptotic properties of these agents in the heart and vasculature. This review focuses on cellular and molecular mechanisms mediating the CVD protective effects of DPP-4i beyond favorable effects on glycemic control.
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80
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Gong Q, Rajagopalan S, Zhong J. Dpp4 inhibition as a therapeutic strategy in cardiometabolic disease: Incretin-dependent and -independent function. Int J Cardiol 2015; 197:170-9. [PMID: 26142202 PMCID: PMC7114201 DOI: 10.1016/j.ijcard.2015.06.076] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 06/03/2015] [Accepted: 06/20/2015] [Indexed: 12/25/2022]
Abstract
Cardiometabolic disorders including obesity, diabetes and cardiovascular disease are among the most severe health problems worldwide. DPP4 enzymatic inhibitors were first developed as anti-diabetic reagents which preserve incretin hormones and promote post-prandial insulin secretion. It's been shown in animal studies that incretin-based therapy has a beneficial effect on cardiovascular disease. Recent studies demonstrated novel non-catalytic functions of DPP4 that may play a role in cardiometabolic disease. Although the role of DPP4 inhibition-mediated incretin effects has been well-reviewed, little information of its incretin-independent actions was introduced in cardiometabolic disease. In the current review, we will summarize the catalytic dependent and independent effects of DPP4 inhibition on cardiometabolic disease. Discuss the findings from recent large scale clinical trials (EXAMINE and SAVOR-TIMI 53) Summarize the catalytic dependent and independent effects of DPP4 inhibition on cardiometabolic disease Focus on recent evidence linking DPP4 inhibition therapy with cardiovascular disease Provide mechanistic insights into the cardiovascular effect of DPP4
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Affiliation(s)
- Quan Gong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, Hubei 434023, PR China
| | - Sanjay Rajagopalan
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Jixin Zhong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, Hubei 434023, PR China; Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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81
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Yamamoto T, Shimano M, Inden Y, Takefuji M, Yanagisawa S, Yoshida N, Tsuji Y, Hirai M, Murohara T. Alogliptin, a dipeptidyl peptidase-4 inhibitor, regulates the atrial arrhythmogenic substrate in rabbits. Heart Rhythm 2015; 12:1362-9. [DOI: 10.1016/j.hrthm.2015.03.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Indexed: 12/27/2022]
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Godinho R, Mega C, Teixeira-de-Lemos E, Carvalho E, Teixeira F, Fernandes R, Reis F. The Place of Dipeptidyl Peptidase-4 Inhibitors in Type 2 Diabetes Therapeutics: A "Me Too" or "the Special One" Antidiabetic Class? J Diabetes Res 2015; 2015:806979. [PMID: 26075286 PMCID: PMC4449938 DOI: 10.1155/2015/806979] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 04/09/2015] [Accepted: 04/11/2015] [Indexed: 12/12/2022] Open
Abstract
Incretin-based therapies, the most recent therapeutic options for type 2 diabetes mellitus (T2DM) management, can modify various elements of the disease, including hypersecretion of glucagon, abnormal gastric emptying, postprandial hyperglycaemia, and, possibly, pancreatic β cell dysfunction. Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) increase glucagon-like peptide-1 (GLP-1) availability and correct the "incretin defect" seen in T2DM patients. Clinical studies have shown good glycaemic control with minimal risk of hypoglycaemia or any other adverse effects, despite the reports of pancreatitis, whose association remains to be proved. Recent studies have been focusing on the putative ability of DPP-4 inhibitors to preserve pancreas function, in particular due to the inhibition of apoptotic pathways and stimulation of β cell proliferation. In addition, other cytoprotective effects on other organs/tissues that are involved in serious T2DM complications, including the heart, kidney, and retina, have been increasingly reported. This review outlines the therapeutic potential of DPP-4 inhibitors for the treatment of T2DM, focusing on their main features, clinical applications, and risks, and discusses the major challenges for the future, in particular the possibility of becoming the preferred therapy for T2DM due to their ability to modify the natural history of the disease and ameliorate nephropathy, retinopathy, and cardiovascular complications.
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Affiliation(s)
- Ricardo Godinho
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, Coimbra University, 3000-548 Coimbra, Portugal
| | - Cristina Mega
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, Coimbra University, 3000-548 Coimbra, Portugal
- ESAV, Polytechnic Institute of Viseu, 3504-510 Viseu, Portugal
| | - Edite Teixeira-de-Lemos
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, Coimbra University, 3000-548 Coimbra, Portugal
- ESAV, Polytechnic Institute of Viseu, 3504-510 Viseu, Portugal
| | - Eugénia Carvalho
- Center for Neuroscience and Cell Biology-Institute for Biomedical Imaging and Life Sciences (CNC.IBILI) Research Unit, University of Coimbra, 3000-548 Coimbra, Portugal
- The Portuguese Diabetes Association (APDP), 1250-189 Lisbon, Portugal
| | - Frederico Teixeira
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, Coimbra University, 3000-548 Coimbra, Portugal
| | - Rosa Fernandes
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, Coimbra University, 3000-548 Coimbra, Portugal
- Center for Neuroscience and Cell Biology-Institute for Biomedical Imaging and Life Sciences (CNC.IBILI) Research Unit, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Flávio Reis
- Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, Coimbra University, 3000-548 Coimbra, Portugal
- Center for Neuroscience and Cell Biology-Institute for Biomedical Imaging and Life Sciences (CNC.IBILI) Research Unit, University of Coimbra, 3000-548 Coimbra, Portugal
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83
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Zhong J, Gong Q, Goud A, Srinivasamaharaj S, Rajagopalan S. Recent Advances in Dipeptidyl-Peptidase-4 Inhibition Therapy: Lessons from the Bench and Clinical Trials. J Diabetes Res 2015; 2015:606031. [PMID: 26075284 PMCID: PMC4446505 DOI: 10.1155/2015/606031] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/23/2015] [Accepted: 04/27/2015] [Indexed: 12/23/2022] Open
Abstract
DPP4 inhibitors (DPP4i) are a class of newly developed antidiabetic drugs which preserve incretin hormones and promote postprandial insulin secretion. Although the cardiovascular effect of DPP4 inhibition has been substantially studied, the exact role of DPP4 in cardiovascular disease especially in humans remains elusive. Previous small studies and meta-analyses have suggested a benefit in both surrogate outcomes and cardiovascular events for these agents. However, there was growing evidence in recent years questioning the cardioprotective effect of DPP4i. Further, a signal of heart failure hospitalization in a recent large scale clinical trial SAVOR-TIMI 53 has called into question the safety of these agents and their utility in the treatment of cardiovascular disease. In this review, we will revisit the physiologic function of DPP4 and discuss its role in cardiometabolic disease based on recent experimental and clinical studies.
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Affiliation(s)
- Jixin Zhong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, Hubei 434023, China
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Quan Gong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, Hubei 434023, China
| | - Aditya Goud
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Srividya Srinivasamaharaj
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sanjay Rajagopalan
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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84
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Rotz ME, Ganetsky VS, Sen S, Thomas TF. Implications of incretin-based therapies on cardiovascular disease. Int J Clin Pract 2015; 69:531-49. [PMID: 25363540 DOI: 10.1111/ijcp.12572] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 09/08/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Incretin-based therapies offer another treatment option for patients with type 2 diabetes. Agents that provide glycaemic control in addition to attenuating cardiovascular disease (CVD) risk factors are important for diabetes management. This review will focus on the off-target effects of incretin-based therapies on CVD risk factors [body weight, blood pressure (BP), lipid profile and albuminuria], major adverse cardiovascular events (MACE), heart failure (HF) and beta-cell preservation. METHODS A literature search was conducted to identify English-language publications for incretin-based therapies evaluating the following off-target end-points: body weight, BP, lipid profile, albuminuria, MACE, HF and beta-cell function. Randomised controlled trials (RCTs) were prioritised as the primary source of information. RESULTS Overall, incretin-based therapies have shown beneficial effects on CVD risk factors, and glucagon-like peptide 1 (GLP-1) receptor agonists appear to have a more pronounced effect compared with dipeptidyl peptidase-4 inhibitors. RCTs are being conducted to determine if these positive effects on CVD risk factors translate to a reduction in MACE. To date, these studies have not shown an increase in MACE. A signal of increased hospitalisations for HF was observed with saxagliptin, warranting continued evaluation and vigilance in high-risk patients. In addition, incretin-based therapies have shown positive effects on measures of beta-cell function supporting their durability in the management of diabetes. CONCLUSIONS Incretin-based therapies are an important treatment option for patients with type 2 diabetes, offering beneficial effects on CVD risk factors without increasing MACE.
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Affiliation(s)
- M E Rotz
- Temple University School of Pharmacy, Philadelphia, PA, USA
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85
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Zhong J, Maiseyeu A, Davis SN, Rajagopalan S. DPP4 in cardiometabolic disease: recent insights from the laboratory and clinical trials of DPP4 inhibition. Circ Res 2015; 116:1491-504. [PMID: 25858071 PMCID: PMC4394189 DOI: 10.1161/circresaha.116.305665] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The discovery of incretin-based medications represents a major therapeutic advance in the pharmacological management of type 2 diabetes mellitus (T2DM), as these agents avoid hypoglycemia, weight gain, and simplify the management of T2DM. Dipeptidyl peptidase-4 (CD26, DPP4) inhibitors are the most widely used incretin-based therapy for the treatment of T2DM globally. DPP4 inhibitors are modestly effective in reducing HbA1c (glycated hemoglobin) (≈0.5%) and while these agents were synthesized with the understanding of the role that DPP4 plays in prolonging the half-life of incretins such as glucagon-like peptide-1 and gastric inhibitory peptide, it is now recognized that incretins are only one of many targets of DPP4. The widespread expression of DPP4 on blood vessels, myocardium, and myeloid cells and the nonenzymatic function of CD26 as a signaling and binding protein, across a wide range of species, suggest a teleological role in cardiovascular regulation and inflammation. Indeed, DPP4 is upregulated in proinflammatory states including obesity, T2DM, and atherosclerosis. Consistent with this maladaptive role, the effects of DPP4 inhibition seem to exert a protective role in cardiovascular disease at least in preclinical animal models. Although 2 large clinical trials suggest a neutral effect on cardiovascular end points, current limitations of performing trials in T2DM over a limited time horizon on top of maximal medical therapy must be acknowledged before rendering judgment on the cardiovascular efficacy of these agents. This review will critically review the science of DPP4 and the effects of DPP4 inhibitors on the cardiovascular system.
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Affiliation(s)
- Jixin Zhong
- From the Divisions of Cardiovascular Medicine and Endocrinology, University of Maryland, Baltimore
| | - Andrei Maiseyeu
- From the Divisions of Cardiovascular Medicine and Endocrinology, University of Maryland, Baltimore
| | - Stephen N Davis
- From the Divisions of Cardiovascular Medicine and Endocrinology, University of Maryland, Baltimore
| | - Sanjay Rajagopalan
- From the Divisions of Cardiovascular Medicine and Endocrinology, University of Maryland, Baltimore.
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86
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Akita K, Isoda K, Shimada K, Daida H. Dipeptidyl-peptidase-4 inhibitor, alogliptin, attenuates arterial inflammation and neointimal formation after injury in low-density lipoprotein (LDL) receptor-deficient mice. J Am Heart Assoc 2015; 4:e001469. [PMID: 25770025 PMCID: PMC4392431 DOI: 10.1161/jaha.114.001469] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background The results of recent studies suggest that dipeptidyl‐peptidase‐4 inhibitors have antiatherogenic effects. However, whether or not dipeptidyl‐peptidase‐4 inhibitors could suppress arterial inflammation and intimal hyperplasia after injury remains undetermined. The present study aims to clarify the anti‐inflammatory effects of the dipeptidyl‐peptidase‐4 inhibitor, alogliptin (AGP), on the arteries of atherogenic low‐density lipoprotein receptor‐deficient (LKO) mice. Methods and Results We compared intimal hyperplasia in LKO mice 2 weeks after femoral artery injury using an external vascular cuff model. All mice received oral injection of AGP (20 mg/kg per day) or normal saline (control) once daily for 14 days. Fasting blood sugar levels, serum cholesterol levels, or blood pressure did not significantly differ between the 2 groups. Plasma levels of active glucagon‐like peptide‐1 were higher in the AGP than in the control LKO mice (22.2±1.9 versus 15.6±0.9 pg/mL; P<0.05). Compared with saline, AGP significantly reduced intimal hyperplasia (1087±127 versus 1896±140 μm2; P<0.001) as well as the intima/media ratio (0.08±0.01 versus 0.16±0.02; P<0.001). Immunostaining showed that AGP reduced proliferating cells (proliferating cell nuclear antigen–positive nuclei; P<0.001), percent smooth‐muscle cell area (α‐SMA‐positive cells; P<0.001), inflammatory cells infiltration (lymphocyte antigen 6 complex–positive cells; P<0.05), tumor necrosis factor‐α expression (P<0.05), and percent phospho‐NF‐κB‐positive cell compared with saline. Levels of tumor necrosis factor ‐α (0.5‐fold P<0.05), monocyte chemoattractant protein 1 (0.3‐fold P<0.01), and interleukin‐1β (0.2‐fold P<0.05) mRNA were lower in the injured arteries of the AGP than in the control group. Conclusions AGP appeared to suppress neointimal formation by inhibiting inflammation, independently of its effects on glucose or cholesterol metabolism in atherogenic LKO mice.
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Affiliation(s)
- Koji Akita
- Division of Cardiology, Juntendo University, Hongo, Tokyo, Japan (K.A., K.I., K.S., H.D.)
| | - Kikuo Isoda
- Division of Cardiology, Juntendo University, Hongo, Tokyo, Japan (K.A., K.I., K.S., H.D.) Division of Cardiovascular Medicine, Department of Internal Medicine 1, National Defense Medical College, Tokorozawa, Japan (K.I.)
| | - Kazunori Shimada
- Division of Cardiology, Juntendo University, Hongo, Tokyo, Japan (K.A., K.I., K.S., H.D.)
| | - Hiroyuki Daida
- Division of Cardiology, Juntendo University, Hongo, Tokyo, Japan (K.A., K.I., K.S., H.D.)
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87
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Ahmed HA, May DW, Fagan SC, Segar L. Vascular Protection with Dipeptidyl Peptidase-IV inhibitors in Diabetes: Experimental and Clinical Therapeutics. Pharmacotherapy 2015; 35:277-97. [DOI: 10.1002/phar.1547] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Heba A. Ahmed
- Program in Clinical and Experimental Therapeutics; Department of Clinical and Administrative Pharmacy and Division of Experience Programs; College of Pharmacy; University of Georgia; Augusta Georgia
- Center for Pharmacy and Experimental Therapeutics; Medical College of Georgia; Georgia Regents University; Augusta Georgia
| | - Dianne W. May
- Program in Clinical and Experimental Therapeutics; Department of Clinical and Administrative Pharmacy and Division of Experience Programs; College of Pharmacy; University of Georgia; Augusta Georgia
- Center for Pharmacy and Experimental Therapeutics; Medical College of Georgia; Georgia Regents University; Augusta Georgia
| | - Susan C. Fagan
- Program in Clinical and Experimental Therapeutics; Department of Clinical and Administrative Pharmacy and Division of Experience Programs; College of Pharmacy; University of Georgia; Augusta Georgia
- Center for Pharmacy and Experimental Therapeutics; Medical College of Georgia; Georgia Regents University; Augusta Georgia
| | - Lakshman Segar
- Program in Clinical and Experimental Therapeutics; Department of Clinical and Administrative Pharmacy and Division of Experience Programs; College of Pharmacy; University of Georgia; Augusta Georgia
- Center for Pharmacy and Experimental Therapeutics; Medical College of Georgia; Georgia Regents University; Augusta Georgia
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88
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Salheen SM, Panchapakesan U, Pollock CA, Woodman OL. The DPP-4 inhibitor linagliptin and the GLP-1 receptor agonist exendin-4 improve endothelium-dependent relaxation of rat mesenteric arteries in the presence of high glucose. Pharmacol Res 2015; 94:26-33. [PMID: 25697548 DOI: 10.1016/j.phrs.2015.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/05/2015] [Accepted: 02/06/2015] [Indexed: 10/24/2022]
Abstract
The aim of the study was to investigate the effects of the DPP-4 inhibitors and GLP-1R agonist, exendin-4 on the mechanism(s) of endothelium-dependent relaxation in rat mesenteric arteries exposed to high glucose concentration (40 mM). Organ bath techniques were employed to investigate vascular endothelial function in rat mesenteric arteries in the presence of normal (11 mM) or high (40 mM) glucose concentrations. Pharmacological tools (1μM TRAM-34, 1μM apamin, 100 nM Ibtx, 100 μM l-NNA, 10 μM ODQ) were used to distinguish between NO and EDHF-mediated relaxation. Superoxide anion levels were assessed by L-012 and lucigenin enhanced-chemiluminescence techniques. Incubation of mesenteric rings with high glucose for 2 h caused a significant increase in superoxide anion generation and a significant impairment of endothelium-dependent relaxation. Exendin-4 and DPP-4 inhibitor linagliptin, but not sitagliptin or vildagliptin, significantly reduced vascular superoxide and improved endothelium-dependent relaxation in the presence of high glucose. The beneficial actions of exendin-4, but not linagliptin, were attenuated by the GLP-1R antagonist exendin fragment (9-39). Further experiments demonstrated that the presence of high glucose impaired the contribution of both nitric oxide and endothelium-dependent hyperpolarisation to relaxation and that linagliptin improved both mechanisms involved in endothelium-dependent relaxation. These findings demonstrate that high glucose impaired endothelium-dependent relaxation can be improved by exendin-4 and linagliptin, likely due to their antioxidant activity and independently of any glucose lowering effect.
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Affiliation(s)
- S M Salheen
- School of Medical Sciences, RMIT University, Melbourne, Australia
| | - U Panchapakesan
- Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, New South Wales, Australia
| | - C A Pollock
- Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, New South Wales, Australia
| | - O L Woodman
- School of Medical Sciences, RMIT University, Melbourne, Australia.
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Circulating Dipeptidyl Peptidase-4 Activity is Associated with Diabetic Retinopathy in Type 1 Diabetic Patients. Eur J Ophthalmol 2015; 25:328-32. [DOI: 10.5301/ejo.5000547] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2014] [Indexed: 01/28/2023]
Abstract
Purpose Diabetic retinopathy (DR) is the most frequent complication among patients with type 1 diabetes mellitus (T1DM). Dipeptidyl peptidase–4 (DPP4) is a protease with elevated activity in patients with T1DM. Several studies indicate that DPP4 inhibitors might have beneficial effect on nonproliferative retinopathy (NPR) development as well as on its progression to proliferative retinopathy (PR). We aimed to explore the relationship between serum DPP4 activity and DR in patients with T1DM. Methods This cross-sectional study recruited 44 patients with T1DM. The DPP4 activity was measured by colorimetric assay in a microplate reader. Photodocumented retinopathy status was made according to the EURODIAB protocol. Results A total of 28 (63.6%) patients were men, mean age 45.36 years, diabetes duration 23.71 years, glycated hemoglobin A1c (HbA1c) 7.4%. Patients were stratified into 2 groups according to retinopathy prevalence. Group 1 comprised 14 (31.85%) patients with DR absence while the second group consisted of 30 (68.15%) patients with both PR and NPR. Group 1 had lower fasting serum DPP4 activity (25.85 vs 33.84 U/L, p<0.001) when compared to the second group. In the binary logistic regression model adjusted for age, sex, diabetes duration, and HbA1c level, DPP4 activity was associated with DR prevalence (odds ratio 1.887 [1.073-3.321]). Conclusions Serum DPP4 activity may be independently associated with both DR types in patients with T1DM. Further study is warranted to elucidate whether there is an association between DPP4 activity and DR severity and/or progression.
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90
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Cameron-Vendrig A, Mundil D, Husain M. Antiatherothrombotic effects of dipeptidyl peptidase inhibitors. Curr Atheroscler Rep 2014; 16:408. [PMID: 24623180 DOI: 10.1007/s11883-014-0408-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Atherothrombotic cardiovascular events are a leading cause of morbidity and mortality in patients with type 2 diabetes (T2D). A number of factors beyond hyperglycemia contribute to this increased risk of cardiovascular events in T2D, including elevated blood pressure, dyslipidemia, inflammation, endothelial dysfunction, and enhanced platelet activation. Importantly, most currently available antihyperglycemic treatments for T2D do not address these additional mechanisms. Indeed, we posit that this may explain why more intensive treatment of hyperglycemia has not contributed to a reduced incidence of cardiovascular events in subjects with T2D. Incretin-targeted therapies, such as dipeptidyl peptidase 4 inhibitors, are a relatively new class of antidiabetic treatments, and preclinical as well as small mechanistic clinical studies suggest that they exert beneficial cardiovascular effects. This review focuses specifically on the potential antiatherothrombotic effects of dipeptidyl peptidase 4 inhibitors.
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Affiliation(s)
- Alison Cameron-Vendrig
- Toronto General Research Institute, TMDT 3-909, 200 Elizabeth St, Toronto, ON, M5G 2C4, Canada
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91
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Triggle CR, Ding H. Cardiovascular impact of drugs used in the treatment of diabetes. Ther Adv Chronic Dis 2014; 5:245-68. [PMID: 25364492 PMCID: PMC4205571 DOI: 10.1177/2040622314546125] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The International Diabetes Federation predicts that by 2035 10% of the population of the world will have been diagnosed with diabetes, raising serious concerns over the resulting elevated morbidity and mortality as well as the impact on health care budgets. It is also well recognized that cardiovascular disease is the primary cause of the high morbidity and mortality associated with diabetes, raising the concern that appropriate drug therapy should not only correct metabolic dysfunction, but also protect the cardiovascular system from the effects of, in particular, the epigenetic changes that result from hyperglycaemia. A number of new classes of drugs for the treatment of diabetes have been introduced in the past decade, providing the opportunity to optimize treatment; however, comparative information of the cardiovascular benefits, or risks, of the newer drugs versus older therapies such as metformin is variable. This review, in addition to summarizing the cellular basis for the therapeutic action of these drugs, addresses the evidence for their cardiovascular benefits and risks. A particular focus is provided on metformin as it is the first choice drug for most patients with type 2 diabetes.
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Affiliation(s)
- Chris R Triggle
- Departments of Pharmacology and Medical Education, Weill Cornell Medical College in Qatar, PO Box 24144, Education City, Doha, Qatar
| | - Hong Ding
- Departments of Pharmacology and Medical Education, Weill Cornell Medical College in Qatar, Education City, Doha, Qatar
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92
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Avogaro A, Fadini GP. The effects of dipeptidyl peptidase-4 inhibition on microvascular diabetes complications. Diabetes Care 2014; 37:2884-94. [PMID: 25249673 DOI: 10.2337/dc14-0865] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We performed a review of the literature to determine whether the dipeptidyl peptidase-4 inhibitors (DPP4-I) may have the capability to directly and positively influence diabetic microvascular complications. The literature was scanned to identify experimental and clinical evidence that DPP4-I can ameliorate diabetic microangiopathy. We retrieved articles published between 1 January 1980 and 1 March 2014 in English-language peer-reviewed journals using the following terms: ("diabetes" OR "diabetic") AND ("retinopathy" OR "retinal" OR "nephropathy" OR "renal" OR "albuminuria" OR "microalbuminuria" OR "neuropathy" OR "ulcer" OR "wound" OR "bone marrow"); ("dipeptidyl peptidase-4" OR "dipeptidyl peptidase-IV" OR "DPP-4" OR "DPP-IV"); and ("inhibition" OR "inhibitor"). Experimentally, DPP4-I appears to improve inflammation, endothelial function, blood pressure, lipid metabolism, and bone marrow function. Several experimental studies report direct potential beneficial effects of DPP4-I on all microvascular diabetes-related complications. These drugs have the ability to act either directly or indirectly via improved glucose control, GLP-1 bioavailability, and modifying nonincretin substrates. Although preliminary clinical data support that DPP4-I therapy can protect from microangiopathy, insufficient evidence is available to conclude that this class of drugs directly prevents or decreases microangiopathy in humans independently from improved glucose control. Experimental findings and preliminary clinical data suggest that DPP4-I, in addition to improving metabolic control, have the potential to interfere with the onset and progression of diabetic microangiopathy. Further evidence is needed to confirm these effects in patients with diabetes.
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Affiliation(s)
- Angelo Avogaro
- Department of Medicine, Division of Metabolic Diseases, University of Padova, Padova, Italy
| | - Gian Paolo Fadini
- Department of Medicine, Division of Metabolic Diseases, University of Padova, Padova, Italy
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93
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Goodwill AG, Mather KJ, Conteh AM, Sassoon D, Noblet JN, Tune JD. Cardiovascular and hemodynamic effects of glucagon-like peptide-1. Rev Endocr Metab Disord 2014; 15:209-17. [PMID: 24881624 PMCID: PMC4119853 DOI: 10.1007/s11154-014-9290-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that has been shown to have hemodynamic and cardioprotective capacity in addition to its better characterized glucoregulatory actions. Because of this, emerging research has focused on the ability of GLP-1 based therapies to drive myocardial substrate selection, enhance cardiac performance and regulate heart rate, blood pressure and vascular tone. These studies have produced consistent and reproducible results amongst numerous laboratories. However, there are obvious disparities in findings obtained in small animal models versus those of higher mammals. This species dependent discrepancy calls to question, the translational value of individual findings. Moreover, few studies of GLP-1 mediated cardiovascular action have been performed in the presence of a pre-existing comorbidities (e.g. obesity/diabetes) which limits interpretation of the effectiveness of incretin-based therapies in the setting of disease. This review addresses cardiovascular and hemodynamic potential of GLP-1 based therapies with attention to species specific effects as well as the interaction between therapies and disease.
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Affiliation(s)
- Adam G. Goodwill
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis IN USA
| | - Kieren J. Mather
- Department of Medicine, Indiana University of School of Medicine, Indianapolis IN USA
| | - Abass M. Conteh
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis IN USA
| | - Daniel Sassoon
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis IN USA
| | - Jillian N. Noblet
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis IN USA
| | - Johnathan D. Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis IN USA
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94
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Ishii M, Shibata R, Kondo K, Kambara T, Shimizu Y, Tanigawa T, Bando YK, Nishimura M, Ouchi N, Murohara T. Vildagliptin stimulates endothelial cell network formation and ischemia-induced revascularization via an endothelial nitric-oxide synthase-dependent mechanism. J Biol Chem 2014; 289:27235-27245. [PMID: 25100725 DOI: 10.1074/jbc.m114.557835] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Dipeptidyl peptidase-4 inhibitors are known to lower glucose levels and are also beneficial in the management of cardiovascular disease. Here, we investigated whether a dipeptidyl peptidase-4 inhibitor, vildagliptin, modulates endothelial cell network formation and revascularization processes in vitro and in vivo. Treatment with vildagliptin enhanced blood flow recovery and capillary density in the ischemic limbs of wild-type mice, with accompanying increases in phosphorylation of Akt and endothelial nitric-oxide synthase (eNOS). In contrast to wild-type mice, treatment with vildagliptin did not improve blood flow in ischemic muscles of eNOS-deficient mice. Treatment with vildagliptin increased the levels of glucagon-like peptide-1 (GLP-1) and adiponectin, which have protective effects on the vasculature. Both vildagliptin and GLP-1 increased the differentiation of cultured human umbilical vein endothelial cells (HUVECs) into vascular-like structures, although vildagliptin was less effective than GLP-1. GLP-1 and vildagliptin also stimulated the phosphorylation of Akt and eNOS in HUVECs. Pretreatment with a PI3 kinase or NOS inhibitor blocked the stimulatory effects of both vildagliptin and GLP-1 on HUVEC differentiation. Furthermore, treatment with vildagliptin only partially increased the limb flow of ischemic muscle in adiponectin-deficient mice in vivo. GLP-1, but not vildagliptin, significantly increased adiponectin expression in differentiated 3T3-L1 adipocytes in vitro. These data indicate that vildagliptin promotes endothelial cell function via eNOS signaling, an effect that may be mediated by both GLP-1-dependent and GLP-1-independent mechanisms. The beneficial activity of GLP-1 for revascularization may also be partially mediated by its ability to increase adiponectin production.
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Affiliation(s)
- Masakazu Ishii
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan,; Department of Oral and Maxillofacial Prosthodontics, Kagoshima University Graduate school of Medical and Dental Science, 890-8544 Kagoshima, Japan
| | - Rei Shibata
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan,.
| | - Kazuhisa Kondo
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan
| | - Takahiro Kambara
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan
| | - Yuuki Shimizu
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan
| | - Tohru Tanigawa
- Department of Otolaryngology, Aichi Medical University, 480-1195 Nagakute, Japan
| | - Yasuko K Bando
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan
| | - Masahiro Nishimura
- Department of Oral and Maxillofacial Prosthodontics, Kagoshima University Graduate school of Medical and Dental Science, 890-8544 Kagoshima, Japan
| | - Noriyuki Ouchi
- Department of Molecular Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan, and
| | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan,.
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95
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Takai S, Sakonjo H, Jin D. Significance of vascular dipeptidyl peptidase-4 inhibition on vascular protection in Zucker diabetic fatty rats. J Pharmacol Sci 2014; 125:386-93. [PMID: 25030743 DOI: 10.1254/jphs.14052fp] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
To clarify the role of dipeptidyl peptidase-4 (DPP-4) inhibition in vascular tissues, we compared the effects of the poorly tissue-penetrative DPP-4 inhibitor sitagliptin to the highly tissue-penetrative DPP-4 inhibitor linagliptin in Zucker diabetic fatty (ZDF) rats. Six-week-old ZDF rats were orally treated with placebo, sitagliptin (10 mg/kg), or linagliptin (3 mg/kg) for 4 weeks. Sitagliptin and linagliptin produced equivalent decreases in blood glucose concentrations and increased plasma insulin concentrations during oral glucose tolerance tests after the first and the last treatments. In isolated arteries, acetylcholine-induced vascular relaxation was significantly augmented by sitagliptin and linagliptin, with significantly stronger relaxation observed with linagliptin compared to sitagliptin. Vascular DPP-4 activity was attenuated by these drugs, with linagliptin producing significant greater attenuation than sitagliptin. Vascular malondialdehide levels were significantly lower with linagliptin compared to sitagliptin. Significantly greater attenuation of vascular gene expressions of p22(phox) and monocyte chemoattractant protein-1 by linagliptin, compared with sitagliptin, was also observed. In conclusion, the superior vascular protection by linagliptin compared with sitagliptin was unrelated to the regulation of circulating glucose and insulin levels, and the stronger vascular DPP-4 inhibition by linagliptin may contribute to the mechanism of vascular protection.
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Affiliation(s)
- Shinji Takai
- Department of Pharmacology, Osaka Medical College, Japan
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96
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Wronkowitz N, Görgens SW, Romacho T, Villalobos LA, Sánchez-Ferrer CF, Peiró C, Sell H, Eckel J. Soluble DPP4 induces inflammation and proliferation of human smooth muscle cells via protease-activated receptor 2. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1613-21. [PMID: 24928308 DOI: 10.1016/j.bbadis.2014.06.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 05/27/2014] [Accepted: 06/02/2014] [Indexed: 12/27/2022]
Abstract
DPP4 is an ubiquitously expressed cell-surface protease that is shedded to the circulation as soluble DPP4 (sDPP4). We recently identified sDPP4 as a novel adipokine potentially linking obesity to the metabolic syndrome. The aim of this study was to investigate direct effects of sDPP4 on human vascular smooth muscle cells (hVSMCs) and to identify responsible signaling pathways. Using physiological concentrations of sDPP4, we could observe a concentration-dependent activation of ERK1/2 (3-fold) after 6h, which remained stable for up to 24h. Additionally, sDPP4 treatment induced a 1.5-fold phosphorylation of the NF-κB subunit p65. In accordance with sDPP4-induced stress and inflammatory signaling, sDPP4 also stimulates hVSMC proliferation. Furthermore we could observe an increased expression and secretion of pro-inflammatory cytokines like interleukin (IL)-6, IL-8 and MCP-1 (2.5-, 2.4- and 1.5-fold, respectively) by the sDPP4 treatment. All direct effects of sDPP4 on signaling, proliferation and inflammation could completely be prevented by DPP4 inhibition. Bioinformatic analysis and signaling signature induced by sDPP4 suggest that sDPP4 might be an agonist for PAR2. After the silencing of PAR2, the sDPP4-induced ERK activation as well as the proliferation was totally abolished. Additionally, the sDPP4-induced upregulation of IL-6 and IL-8 could completely be prevented by the PAR2 silencing. In conclusion, we show for the first time that sDPP4 directly activates the MAPK and NF-κB signaling cascade involving PAR2 and resulting in the induction of inflammation and proliferation of hVSMC. Thus, our in vitro data might extend the current view of sDPP4 action and shed light on cardiovascular effects of DPP4-inhibitors.
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Affiliation(s)
- Nina Wronkowitz
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, 40225 Düsseldorf, Germany
| | - Sven W Görgens
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, 40225 Düsseldorf, Germany
| | - Tania Romacho
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, 40225 Düsseldorf, Germany
| | - Laura A Villalobos
- Department of Pharmacology and Therapeutics, School of Medicine, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Carlos F Sánchez-Ferrer
- Department of Pharmacology and Therapeutics, School of Medicine, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Concepción Peiró
- Department of Pharmacology and Therapeutics, School of Medicine, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Henrike Sell
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, 40225 Düsseldorf, Germany.
| | - Jürgen Eckel
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, 40225 Düsseldorf, Germany
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97
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Gonçalves A, Marques C, Leal E, Ribeiro CF, Reis F, Ambrósio AF, Fernandes R. Dipeptidyl peptidase-IV inhibition prevents blood-retinal barrier breakdown, inflammation and neuronal cell death in the retina of type 1 diabetic rats. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1454-63. [PMID: 24769045 DOI: 10.1016/j.bbadis.2014.04.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 04/04/2014] [Accepted: 04/11/2014] [Indexed: 12/21/2022]
Abstract
Diabetic retinopathy, a leading cause of vision loss in working-age population, is often associated with inflammation and apoptosis. We have previously reported that sitagliptin, a DPP-IV inhibitor, exerts beneficial effects in the retina of type 2 diabetic animals. The present study aimed to evaluate whether sitagliptin can exert protective effects in the retina of type 1 diabetic animals by a mechanism independent of insulin secretion and glycemia normalization. Streptozotocin-induced diabetic rats were treated orally with sitagliptin (5mg/kg/day) for the last two weeks of 4 weeks of diabetes. Sitagliptin treatment did not change the weight and glucose, HbA1c or insulin levels. However, it prevented the diabetes-induced increase in DPP-IV/CD26 activity and levels in serum and retina. Sitagliptin also prevented the increase in blood-retinal barrier (BRB) permeability and inhibited the changes in immunoreactivity and endothelial subcellular distribution of occludin, claudin-5 and ZO-1 proteins induced by diabetes. Furthermore, sitagliptin decreased the retinal inflammatory state and neuronal apoptosis. Sitagliptin inhibited the BRB breakdown in a type 1 diabetic animal model, by a mechanism independent of normalization of glycemia, by preventing changes in tight junctions (TJs) organization. Sitagliptin also exerted protective effects against inflammation and pro-apoptotic state in the retina of diabetic rats. Altogether, these results suggest that sitagliptin might be envisaged to be used to prevent or delay some of the alterations associated with the development of diabetic retinopathy.
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Affiliation(s)
- Andreia Gonçalves
- Laboratory of Pharmacology and Experimental Therapeutics, IBILI - Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Portugal
| | - Catarina Marques
- Laboratory of Pharmacology and Experimental Therapeutics, IBILI - Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Portugal
| | - Ermelindo Leal
- Centre for Neuroscience and Cell Biology, University of Coimbra, Portugal
| | - Carlos F Ribeiro
- Laboratory of Pharmacology and Experimental Therapeutics, IBILI - Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Portugal
| | - Flávio Reis
- Laboratory of Pharmacology and Experimental Therapeutics, IBILI - Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Portugal
| | - António F Ambrósio
- Centre of Ophthalmology and Vision Sciences, IBILI, Faculty of Medicine, University of Coimbra, Portugal; AIBILI, University of Coimbra, Portugal
| | - Rosa Fernandes
- Laboratory of Pharmacology and Experimental Therapeutics, IBILI - Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Portugal.
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98
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Romacho T, Elsen M, Röhrborn D, Eckel J. Adipose tissue and its role in organ crosstalk. Acta Physiol (Oxf) 2014; 210:733-53. [PMID: 24495317 DOI: 10.1111/apha.12246] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/18/2013] [Accepted: 01/28/2014] [Indexed: 12/13/2022]
Abstract
The discovery of adipokines has revealed adipose tissue as a central node in the interorgan crosstalk network, which mediates the regulation of multiple organs and tissues. Adipose tissue is a true endocrine organ that produces and secretes a wide range of mediators regulating adipose tissue function in an auto-/paracrine manner and important distant targets, such as the liver, skeletal muscle, the pancreas and the cardiovascular system. In metabolic disorders such as obesity, enlargement of adipocytes leads to adipose tissue dysfunction and a shift in the secretory profile with an increased release of pro-inflammatory adipokines. Adipose tissue dysfunction has a central role in the development of insulin resistance, type 2 diabetes, and cardiovascular diseases. Besides the well-acknowledged role of adipokines in metabolic diseases, and the increasing number of adipokines being discovered in the last years, the mechanisms underlying the release of many adipokines from adipose tissue remain largely unknown. To combat metabolic diseases, it is crucial to better understand how adipokines can modulate adipose tissue growth and function. Therefore, we will focus on adipokines with a prominent role in auto-/paracrine crosstalk within the adipose tissue such as RBP4, HO-1, WISP2, SFRPs and chemerin. To depict the endocrine crosstalk between adipose tissue with skeletal muscle, the cardiovascular system and the pancreas, we will report the main findings regarding the direct effects of adiponectin, leptin, DPP4 and visfatin on skeletal muscle insulin resistance, cardiovascular function and β-cell growth and function.
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Affiliation(s)
- T. Romacho
- Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
| | - M. Elsen
- Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
| | - D. Röhrborn
- Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
| | - J. Eckel
- Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
- German Center for Diabetes Research (DZD e.V.); Düsseldorf Germany
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99
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Manrique C, Lastra G, Sowers JR. New insights into insulin action and resistance in the vasculature. Ann N Y Acad Sci 2014; 1311:138-50. [PMID: 24650277 DOI: 10.1111/nyas.12395] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Two-thirds of adults in the United States are overweight or obese, and another 26 million have type 2 diabetes. Decreased insulin sensitivity in cardiovascular tissue is an underlying abnormality in these individuals. Insulin metabolic signaling increases endothelial cell nitric oxide (NO) production. Impaired vascular insulin sensitivity is an early defect leading to impaired vascular relaxation. In overweight and obese persons, as well as in those with hypertension, systemic and vascular insulin resistance often occur in conjunction with activation of the cardiovascular tissue renin-angiotensin-aldosterone system (RAAS). Activated angiotensin II type 1 receptor and mineralocorticoid receptor signaling promote the development of vascular insulin resistance and impaired endothelial NO-mediated relaxation. Research in this area has implicated excessive serine phosphorylation and proteasomal degradation of the docking protein insulin receptor substrate and enhanced signaling through hybrid insulin/insulin-like growth factor receptor as important mechanisms underlying RAAS impediment of downstream vascular insulin metabolic signaling. This review will present recent evidence supporting the notion that RAAS signaling represents a potential pathway for the development of vascular insulin resistance and impaired endothelial-mediated vasodilation.
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Affiliation(s)
- Camila Manrique
- Division of Endocrinology, Department of Internal Medicine, University of Missouri, Columbia, Missouri; Harry S. Truman Veteran's Hospital, Columbia, Missouri
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100
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Kuc RE, Maguire JJ, Siew K, Patel S, Derksen DR, Margaret Jackson V, O'Shaughnessey KM, Davenport AP. Characterization of [¹²⁵I]GLP-1(9-36), a novel radiolabeled analog of the major metabolite of glucagon-like peptide 1 to a receptor distinct from GLP1-R and function of the peptide in murine aorta. Life Sci 2014; 102:134-8. [PMID: 24641952 DOI: 10.1016/j.lfs.2014.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/29/2014] [Accepted: 03/04/2014] [Indexed: 12/26/2022]
Abstract
AIMS Glucagon-like peptide 1 (GLP-1) is an insulin secretagogue, released in response to meal ingestion and efficiently lowers blood glucose in Type 2 diabetic patients. GLP-1(7-36) is rapidly metabolized by dipeptidyl peptidase IV to the major metabolite GLP-1(9-36)-amide, often thought to be inactive. Inhibitors of this enzyme are widely used to treat diabetes. Our aim was to characterize the binding of GLP-1(9-36) to native mouse tissues and to cells expressing GLP1-R as well as to measure functional responses in the mouse aorta compared with GLP-1(7-36). MAIN METHODS The affinity of [(125)I]GLP-1(7-36) and [(125)I]GLP-1(9-36) was measured in mouse tissues by saturation binding and autoradiography used to determine receptor distribution. The affinity of both peptides was compared in binding to recombinant GLP-1 receptors using cAMP and scintillation proximity assays. Vasoactivity was determined in mouse aortae in vitro. KEY FINDINGS In cells expressing GLP-1 receptors, GLP-1(7-36) bound with the expected high affinities (0.1 nM) and an EC50 of 0.07 nM in cAMP assays but GLP-1(9-36) bound with 70,000 and 100,000 fold lower affinities respectively. In contrast, in mouse brain, both labeled peptides bound with a single high affinity, with Hill slopes close to unity, although receptor density was an order of magnitude lower for [(125)I]GLP-1(9-36). In functional experiments both peptides had similar potencies, GLP-1(7-36), pD2=7.40 ± 0.24 and GLP-1(9-36), pD2=7.57 ± 0.64. SIGNIFICANCE These results suggest that GLP-1(9-36) binds and has functional activity in the vasculature but these actions may be via a pathway that is distinct from the classical GLP-1 receptor and insulin secretagogue actions.
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Affiliation(s)
- Rhoda E Kuc
- Clinical Pharmacology Unit, Box 110, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Janet J Maguire
- Clinical Pharmacology Unit, Box 110, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Keith Siew
- Clinical Pharmacology Unit, Box 110, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Sheena Patel
- Pfizer, Cardiovascular Medicine, Cambridge, MA, USA
| | | | | | | | - Anthony P Davenport
- Clinical Pharmacology Unit, Box 110, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
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