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Olver TD, McDonald MW, Klakotskaia D, Richardson RA, Jasperse JL, Melling CWJ, Schachtman TR, Yang HT, Emter CA, Laughlin MH. A chronic physical activity treatment in obese rats normalizes the contributions of ET-1 and NO to insulin-mediated posterior cerebral artery vasodilation. J Appl Physiol (1985) 2017; 122:1040-1050. [PMID: 28183819 DOI: 10.1152/japplphysiol.00811.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/11/2017] [Accepted: 02/02/2017] [Indexed: 12/31/2022] Open
Abstract
This study tested the hypotheses that obesity-induced decrements in insulin-stimulated cerebrovascular vasodilation would be normalized with acute endothelin-1a receptor antagonism and that treatment with a physical activity intervention restores vasoreactivity to insulin through augmented nitric oxide synthase (NOS)-dependent dilation. Otsuka Long-Evans Tokushima Fatty rats were divided into the following groups: 20 wk old food controlled (CON-20); 20 wk old free food access (model of obesity, OB-20); 40 wk old food controlled (CON-40); 40 wk old free food access (OB-40); and 40 wk old free food access+RUN (RUN-40; wheel-running access from 20 to 40 wk). Rats underwent Barnes maze testing and a euglycemic hyperinsulinemic clamp (EHC). In the 40-wk cohort, cerebellum and hippocampus blood flow (BF) were examined (microsphere infusion). Vasomotor responses (pressurized myography) to insulin were assessed in untreated, endothelin-1a receptor antagonism, and NOS inhibition conditions in posterior cerebral arteries. Insulin-stimulated vasodilation was attenuated in the OB vs. CON and RUN groups (P ≤ 0.04). Dilation to insulin was normalized with endothelin-1a receptor antagonism in the OB groups (between groups, P ≥ 0.56), and insulin-stimulated NOS-mediated dilation was greater in the RUN-40 vs. OB-40 group (P < 0.01). At 40 wk of age, cerebellum BF decreased during EHC in the OB-40 group (P = 0.02) but not CON or RUN groups (P ≥ 0.36). Barnes maze testing revealed increased entry errors and latencies in the RUN-40 vs. CON and OB groups (P < 0.01). These findings indicate that obesity-induced impairments in vasoreactivity to insulin involve increased endothelin-1 and decreased nitric oxide signaling. Chronic spontaneous physical activity, initiated after disease onset, reversed impaired vasodilation to insulin and decreased Barnes maze performance, possibly because of increased exploratory behavior.NEW & NOTEWORTHY The new and noteworthy findings are that 1) in rodents, obesity-related deficits in insulin-mediated vasodilation are associated with increased influence of insulin-stimulated ET-1 and depressed influence of insulin-stimulated NOS and 2) a physical activity intervention, initiated after the onset of disease, restores insulin-mediated vasodilation, likely by normalizing insulin-stimulated ET-1 and NOS balance. These data demonstrate that the treatment effects of chronic exercise on insulin-mediated vasodilation extend beyond active skeletal muscle vasculature and include the cerebrovasculature.
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Affiliation(s)
- T Dylan Olver
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri;
| | - Matthew W McDonald
- Department of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - Diana Klakotskaia
- Department of Psychological Sciences, University of Missouri-Columbia, Columbia, Missouri; and
| | - Rachel A Richardson
- Department of Psychological Sciences, University of Missouri-Columbia, Columbia, Missouri; and
| | | | - C W James Melling
- Department of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - Todd R Schachtman
- Department of Psychological Sciences, University of Missouri-Columbia, Columbia, Missouri; and
| | - Hsiao T Yang
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri
| | - Craig A Emter
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri
| | - M Harold Laughlin
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri
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Altara R, Giordano M, Nordén ES, Cataliotti A, Kurdi M, Bajestani SN, Booz GW. Targeting Obesity and Diabetes to Treat Heart Failure with Preserved Ejection Fraction. Front Endocrinol (Lausanne) 2017; 8:160. [PMID: 28769873 PMCID: PMC5512012 DOI: 10.3389/fendo.2017.00160] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 06/23/2017] [Indexed: 12/12/2022] Open
Abstract
Heart failure with preserved ejection fraction (HFpEF) is a major unmet medical need that is characterized by the presence of multiple cardiovascular and non-cardiovascular comorbidities. Foremost among these comorbidities are obesity and diabetes, which are not only risk factors for the development of HFpEF, but worsen symptoms and outcome. Coronary microvascular inflammation with endothelial dysfunction is a common denominator among HFpEF, obesity, and diabetes that likely explains at least in part the etiology of HFpEF and its synergistic relationship with obesity and diabetes. Thus, pharmacological strategies to supplement nitric oxide and subsequent cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling may have therapeutic promise. Other potential approaches include exercise and lifestyle modifications, as well as targeting endothelial cell mineralocorticoid receptors, non-coding RNAs, sodium glucose transporter 2 inhibitors, and enhancers of natriuretic peptide protective NO-independent cGMP-initiated and alternative signaling, such as LCZ696 and phosphodiesterase-9 inhibitors. Additionally, understanding the role of adipokines in HFpEF may lead to new treatments. Identifying novel drug targets based on the shared underlying microvascular disease process may improve the quality of life and lifespan of those afflicted with both HFpEF and obesity or diabetes, or even prevent its occurrence.
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Affiliation(s)
- Raffaele Altara
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Center for Cardiac Research, Oslo, Norway
- Department of Pathology, School of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
- *Correspondence: Raffaele Altara,
| | - Mauro Giordano
- Department of Medical, Surgical, Neurological, Metabolic and Geriatrics Sciences, University of Campania “L. Vanvitelli”, Caserta, Italy
| | - Einar S. Nordén
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Center for Cardiac Research, Oslo, Norway
- Bjørknes College, Oslo, Norway
| | - Alessandro Cataliotti
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- KG Jebsen Center for Cardiac Research, Oslo, Norway
| | - Mazen Kurdi
- Faculty of Sciences, Department of Chemistry and Biochemistry, Lebanese University, Hadath, Lebanon
| | - Saeed N. Bajestani
- Department of Pathology, School of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
- Department of Ophthalmology, School of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
| | - George W. Booz
- Department of Pharmacology and Toxicology, School of Medicine, University of Mississippi Medical Center, Jackson, MS, United States
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Asih PR, Tegg ML, Sohrabi H, Carruthers M, Gandy SE, Saad F, Verdile G, Ittner LM, Martins RN. Multiple Mechanisms Linking Type 2 Diabetes and Alzheimer's Disease: Testosterone as a Modifier. J Alzheimers Dis 2017; 59:445-466. [PMID: 28655134 PMCID: PMC6462402 DOI: 10.3233/jad-161259] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Evidence in support of links between type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has increased considerably in recent years. AD pathological hallmarks include the accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated tau in the brain, which are hypothesized to promote inflammation, oxidative stress, and neuronal loss. T2DM exhibits many AD pathological features, including reduced brain insulin uptake, lipid dysregulation, inflammation, oxidative stress, and depression; T2DM has also been shown to increase AD risk, and with increasing age, the prevalence of both conditions increases. In addition, amylin deposition in the pancreas is more common in AD than in normal aging, and although there is no significant increase in cerebral Aβ deposition in T2DM, the extent of Aβ accumulation in AD correlates with T2DM duration. Given these similarities and correlations, there may be common underlying mechanism(s) that predispose to both T2DM and AD. In other studies, an age-related gradual loss of testosterone and an increase in testosterone resistance has been shown in men; low testosterone levels can also occur in women. In this review, we focus on the evidence for low testosterone levels contributing to an increased risk of T2DM and AD, and the potential of testosterone treatment in reducing this risk in both men and women. However, such testosterone treatment may need to be long-term, and would need regular monitoring to maintain testosterone at physiological levels. It is possible that a combination of testosterone therapy together with a healthy lifestyle approach, including improved diet and exercise, may significantly reduce AD risk.
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Affiliation(s)
- Prita R. Asih
- Department of Anatomy, Dementia Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
| | - Michelle L. Tegg
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
| | - Hamid Sohrabi
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
- Australian Alzheimer’s Research Foundation Perth, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
| | | | - Samuel E. Gandy
- Departments of Neurology and Psychiatry and the Alzheimer’s Disease Research Center, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY, USA
| | - Farid Saad
- Bayer Pharma AG, Global Medical Affairs Andrology, Berlin, Germany
- Gulf Medical University School of Medicine, Ajman, UAE
| | - Giuseppe Verdile
- Australian Alzheimer’s Research Foundation Perth, WA, Australia
- School of Biomedical Sciences, Curtin University of Technology, Bentley, WA, Australia
| | - Lars M. Ittner
- Department of Anatomy, Dementia Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Neuroscience Research Australia, Sydney, NSW, Australia
| | - Ralph N. Martins
- KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
- Australian Alzheimer’s Research Foundation Perth, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
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