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Keller AC, Chun JH, Knaub L, Henckel M, Hull S, Scalzo R, Pott G, Walker L, Reusch J. Thermoneutrality induces vascular dysfunction and impaired metabolic function in male Wistar rats: a new model of vascular disease. J Hypertens 2022; 40:2133-2146. [PMID: 35881464 PMCID: PMC9553250 DOI: 10.1097/hjh.0000000000003153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Cardiovascular disease is of paramount importance, yet there are few relevant rat models to investigate its pathology and explore potential therapeutics. Housing at thermoneutral temperature (30 °C) is being employed to humanize metabolic derangements in rodents. We hypothesized that housing rats in thermoneutral conditions would potentiate a high-fat diet, resulting in diabetes and dysmetabolism, and deleteriously impact vascular function, in comparison to traditional room temperature housing (22 °C). METHODS Male Wistar rats were housed at either room temperature or thermoneutral temperatures for 16 weeks on either a low or high-fat diet. Glucose and insulin tolerance tests were conducted at the beginning and end of the study. At the study's conclusion, vasoreactivity and mitochondrial respiration of aorta and carotid were conducted. RESULTS We observed diminished vasodilation in vessels from thermoneutral rats ( P < 0.05), whereas high-fat diet had no effect. This effect was also observed in endothelium-denuded aorta in thermoneutral rats ( P < 0.05). Vasoconstriction was significantly elevated in aorta of thermoneutral rats ( P < 0.05). Diminished nitric oxide synthase activity and nitrotyrosine, and elevated glutathione activity were observed in aorta from rats housed under thermoneutral conditions, indicating a climate of lower nitric oxide and excess reactive oxygen species in aorta. Thermoneutral rat aorta also demonstrated less mitochondrial respiration with lipid substrates compared with the controls ( P < 0.05). CONCLUSION Our data support that thermoneutrality causes dysfunctional vasoreactivity, decreased lipid mitochondrial metabolism, and modified cellular signaling. These are critical observations as thermoneutrality is becoming prevalent for translational research models. This new model of vascular dysfunction may be useful for dissection of targetable aspects of cardiovascular disease and is a novel and necessary model of disease.
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Affiliation(s)
- Amy C. Keller
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
| | | | - L.A. Knaub
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
| | - M.M. Henckel
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
| | - S.E. Hull
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
| | - R.L. Scalzo
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
| | - G.B. Pott
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
| | - L.A. Walker
- Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - J.E.B. Reusch
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Anschutz Medical Campus
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado
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Zhang X, Gao F. Exercise improves vascular health: Role of mitochondria. Free Radic Biol Med 2021; 177:347-359. [PMID: 34748911 DOI: 10.1016/j.freeradbiomed.2021.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/20/2021] [Accepted: 11/02/2021] [Indexed: 01/10/2023]
Abstract
Vascular mitochondria constantly integrate signals from environment and respond accordingly to match vascular function to metabolic requirements of the organ tissues, while mitochondrial dysfunction contributes to vascular aging and pathologies such as atherosclerosis, stenosis, and hypertension. As an effective lifestyle intervention, exercise induces extensive mitochondrial adaptations through vascular mechanical stress and the increased production and release of reactive oxygen species and nitric oxide that activate multiple intracellular signaling pathways, among which peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) plays a critical role. PGC-1α coordinates mitochondrial quality control mechanisms to maintain a healthy mitochondrial pool and promote endothelial nitric oxide synthase activity in vasculature. The mitochondrial adaptations to exercise improve bioenergetics, balance redox status, protect endothelial cells against detrimental insults, increase vascular plasticity, and ameliorate aging-related vascular dysfunction, thus benefiting vascular health. This review highlights recent findings of mitochondria as a central hub integrating exercise-afforded vascular benefits and its underlying mechanisms. A better understanding of the mitochondrial adaptations to exercise will not only shed light on the mechanisms of exercise-induced cardiovascular protection, but may also provide new clues to mitochondria-oriented precise exercise prescriptions for cardiovascular health.
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Affiliation(s)
- Xing Zhang
- Key Laboratory of Aerospace Medicine of the Ministry of Education, School of Aerospace Medicine, Fourth Military Medical University, Xi'an, 710032, China.
| | - Feng Gao
- Key Laboratory of Aerospace Medicine of the Ministry of Education, School of Aerospace Medicine, Fourth Military Medical University, Xi'an, 710032, China.
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Gioscia-Ryan RA, Clayton ZS, Zigler MC, Richey JJ, Cuevas LM, Rossman MJ, Battson ML, Ziemba BP, Hutton DA, VanDongen NS, Seals DR. Lifelong voluntary aerobic exercise prevents age- and Western diet- induced vascular dysfunction, mitochondrial oxidative stress and inflammation in mice. J Physiol 2020; 599:911-925. [PMID: 33103241 DOI: 10.1113/jp280607] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 09/28/2020] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS The results of the present study establish the temporal pattern of age-related vascular dysfunction across the adult lifespan in sedentary mice consuming a non-Western diet, and the underlying mechanisms The results demonstrate that consuming a Western diet accelerates and exacerbates vascular ageing across the lifespan in sedentary mice They also show that lifelong voluntary aerobic exercise has remarkable protective effects on vascular function throughout the lifespan, in the setting of ageing alone, as well as ageing compounded by Western diet consumption Overall, the results indicate that amelioration of mitochondrial oxidative stress and inflammation are key mechanisms underlying the voluntary aerobic exercise-associated preservation of vascular function across the lifespan in both the presence and absence of a Western dietary pattern ABSTRACT: Advancing age is the major risk factor for cardiovascular diseases, driven largely by vascular endothelial dysfunction (impaired endothelium-dependent dilatation, EDD) and aortic stiffening (increased aortic pulse wave velocity, aPWV). In humans, vascular ageing occurs in the presence of differences in diet and physical activity, but the interactive effects of these factors are unknown. We assessed carotid artery EDD and aPWV across the lifespan in mice consuming standard (normal) low-fat chow (NC) or a high-fat/high-sucrose Western diet (WD) in the absence (sedentary, SED) or presence (voluntary wheel running, VWR) of aerobic exercise. Ageing impaired nitric oxide-mediated EDD (peak EDD 88 ± 12% 6 months P = 0.003 vs. 59 ± 9% 27 months NC-SED), which was accelerated by WD (60 ± 18% 6 months WD-SED). In NC mice, aPWV increased 32% with age (423 ± 13 cm/s at 24 months P < 0.001 vs. 321 ± 12 cm/s at 6 months) and absolute values were an additional ∼10% higher at any age in WD mice (P = 0.042 vs. NC-SED). Increases in aPWV with age in NC and WD mice were associated with 30-65% increases in aortic intrinsic wall stiffness (6 vs. 19-27 months, P = 0.007). Lifelong aerobic exercise prevented age- and WD-related vascular dysfunction across the lifespan, and this protection appeared to be mediated by mitigation of vascular mitochondrial oxidative stress and inflammation. Our results depict the temporal impairment of vascular function over the lifespan in mice, acceleration and exacerbation of that dysfunction with WD consumption, the remarkable protective effects of voluntary aerobic exercise, and the underlying mechanisms.
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Affiliation(s)
- Rachel A Gioscia-Ryan
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Zachary S Clayton
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Melanie C Zigler
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - James J Richey
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Lauren M Cuevas
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Matthew J Rossman
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Micah L Battson
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Brian P Ziemba
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - David A Hutton
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Nicholas S VanDongen
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Douglas R Seals
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
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Gioscia-Ryan RA, Clayton ZS, Fleenor BS, Eng JS, Johnson LC, Rossman MJ, Zigler MC, Evans TD, Seals DR. Late-life voluntary wheel running reverses age-related aortic stiffness in mice: a translational model for studying mechanisms of exercise-mediated arterial de-stiffening. GeroScience 2020; 43:423-432. [PMID: 32529594 PMCID: PMC8050175 DOI: 10.1007/s11357-020-00212-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/02/2020] [Indexed: 01/02/2023] Open
Abstract
Aortic stiffening, assessed as pulse-wave velocity (PWV), increases with age and is an important antecedent to, and independent predictor of, cardiovascular diseases (CVD) and other clinical disorders of aging. Aerobic exercise promotes lower levels of aortic stiffness in older adults, but the underlying mechanisms are incompletely understood, largely due to inherent challenges of mechanistic studies of large elastic arteries in humans. Voluntary wheel running (VWR) is distinct among experimental animal exercise paradigms in that it allows investigation of the physiologic effects of aerobic training without potential confounding influences of aversive molecular signaling related to forced exercise. In this study, we investigated whether VWR in mice may be a suitable model for mechanistic studies (i.e., "reverse translation") of the beneficial effects of exercise on arterial stiffness in humans. We found that 10 weeks of VWR in old mice (~ 28 months) reversed age-related elevations in aortic PWV assessed in vivo (Old VWR: 369 ± 19 vs. old sedentary: 439 ± 20 cm/s, P < 0.05). The de-stiffening effects of VWR were accompanied by normalization of age-related increases in ex vivo mechanical stiffness of aortic segments and aortic accumulation of collagen-I and advanced glycation end products, as well as lower levels of aortic superoxide and nitrotyrosine. Our results suggest that late-life VWR in mice recapitulates the aortic de-stiffening effects of exercise in humans and indicates important mechanistic roles for decreased oxidative stress and extracellular matrix remodeling. Therefore, VWR is a suitable model for further study of the mechanisms underlying beneficial effects of exercise on arterial stiffness.
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Affiliation(s)
- Rachel A. Gioscia-Ryan
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | - Zachary S. Clayton
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | | | - Jason S. Eng
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | - Lawrence C. Johnson
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | - Matthew J. Rossman
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | - Melanie C. Zigler
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | - Trent D. Evans
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
| | - Douglas R. Seals
- Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309 USA
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Abushamat LA, McClatchey PM, Scalzo RL, Schauer I, Huebschmann AG, Nadeau KJ, Liu Z, Regensteiner JG, Reusch JEB. Mechanistic Causes of Reduced Cardiorespiratory Fitness in Type 2 Diabetes. J Endocr Soc 2020; 4:bvaa063. [PMID: 32666009 PMCID: PMC7334033 DOI: 10.1210/jendso/bvaa063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/04/2020] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes (T2D) has been rising in prevalence in the United States and worldwide over the past few decades and contributes to significant morbidity and premature mortality, primarily due to cardiovascular disease (CVD). Cardiorespiratory fitness (CRF) is a modifiable cardiovascular (CV) risk factor in the general population and in people with T2D. Young people and adults with T2D have reduced CRF when compared with their peers without T2D who are similarly active and of similar body mass index. Furthermore, the impairment in CRF conferred by T2D is greater in women than in men. Various factors may contribute to this abnormality in people with T2D, including insulin resistance and mitochondrial, vascular, and cardiac dysfunction. As proof of concept that understanding the mediators of impaired CRF in T2D can inform intervention, we previously demonstrated that an insulin sensitizer improved CRF in adults with T2D. This review focuses on how contributing factors influence CRF and why they may be compromised in T2D. Functional exercise capacity is a measure of interrelated systems biology; as such, the contribution of derangement in each of these factors to T2D-mediated impairment in CRF is complex and varied. Therefore, successful approaches to improve CRF in T2D should be multifaceted and individually designed. The current status of this research and future directions are outlined.
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Affiliation(s)
- Layla A Abushamat
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | | | - Rebecca L Scalzo
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Rocky Mountain Regional VA, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Irene Schauer
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Rocky Mountain Regional VA, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Amy G Huebschmann
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Kristen J Nadeau
- Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Zhenqi Liu
- Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Judith G Regensteiner
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Jane E B Reusch
- Department of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado.,Rocky Mountain Regional VA, Aurora, Colorado.,Center for Women's Health Research, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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Kunimoto M, Shimada K, Yokoyama M, Matsubara T, Aikawa T, Ouchi S, Shimizu M, Fukao K, Miyazaki T, Kadoguchi T, Fujiwara K, Abulimiti A, Honzawa A, Yamada M, Shimada A, Yamamoto T, Asai T, Amano A, Smit AJ, Daida H. Association between the tissue accumulation of advanced glycation end products and exercise capacity in cardiac rehabilitation patients. BMC Cardiovasc Disord 2020; 20:195. [PMID: 32326893 PMCID: PMC7178950 DOI: 10.1186/s12872-020-01484-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 04/14/2020] [Indexed: 12/15/2022] Open
Abstract
Background Advanced glycation end products (AGEs) are associated with aging, diabetes mellitus (DM), and other chronic diseases. Recently, the accumulation of AGEs can be evaluated by skin autofluorescence (SAF). However, the relationship between SAF levels and exercise capacity in patients with cardiovascular disease (CVD) remains unclear. This study aimed to investigate the association between the tissue accumulation of AGEs and clinical characteristics, including exercise capacity, in patients with CVD. Methods We enrolled 319 consecutive CVD patients aged ≥40 years who underwent early phase II cardiac rehabilitation (CR) at our university hospital between November 2015 and September 2017. Patient background, clinical data, and the accumulation of AGEs assessed by SAF were recorded at the beginning of CR. Characteristics were compared between two patient groups divided according to the median SAF level (High SAF and Low SAF). Results The High SAF group was significantly older and exhibited a higher prevalence of DM than the Low SAF group. The sex ratio did not differ between the two groups. AGE levels showed significant negative correlations with peak oxygen uptake and ventilator efficiency (both P < 0.0001). Exercise capacity was significantly lower in the high SAF group than in the low SAF group, regardless of the presence or absence of DM (P < 0.05). A multivariate logistic regression analysis showed that SAF level was an independent factor associated with reduced exercise capacity (odds ratio 2.10; 95% confidence interval 1.13–4.05; P = 0.02). Conclusion High levels of tissue accumulated AGEs, as assessed by SAF, were significantly and independently associated with reduced exercise capacity. These data suggest that measuring the tissue accumulation of AGEs may be useful in patients who have undergone CR, irrespective of whether they have DM.
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Affiliation(s)
- Mitsuhiro Kunimoto
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Kazunori Shimada
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan. .,Cardiovascular Rehabilitation and Fitness, Juntendo University Hospital, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| | - Miho Yokoyama
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.,Cardiovascular Rehabilitation and Fitness, Juntendo University Hospital, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Tomomi Matsubara
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Tatsuro Aikawa
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Shohei Ouchi
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Megumi Shimizu
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Kosuke Fukao
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Tetsuro Miyazaki
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Tomoyasu Kadoguchi
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Kei Fujiwara
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Abidan Abulimiti
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Akio Honzawa
- Cardiovascular Rehabilitation and Fitness, Juntendo University Hospital, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Miki Yamada
- Cardiovascular Rehabilitation and Fitness, Juntendo University Hospital, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Akie Shimada
- Department of Cardiovascular Surgery, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Taira Yamamoto
- Department of Cardiovascular Surgery, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Tohru Asai
- Department of Cardiovascular Surgery, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Atsushi Amano
- Department of Cardiovascular Surgery, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Andries J Smit
- Division of Vascular Medicine, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, Groningen, 9713 GZ, Netherlands
| | - Hiroyuki Daida
- Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.,Faculty of Health Science, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
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8
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Sepiapterin Improves Vascular Reactivity and Insulin-Stimulated Glucose in Wistar Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7363485. [PMID: 30344886 PMCID: PMC6174728 DOI: 10.1155/2018/7363485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/19/2018] [Accepted: 07/25/2018] [Indexed: 11/17/2022]
Abstract
In the vasculature, sedentary behavior leads to endothelial abnormalities, resulting in elevated cardiovascular disease risk. Endothelial nitric oxide synthase (eNOS) aberrations characterize endothelial dysfunction; eNOS also regulates mitochondrial function. We hypothesized that sepiapterin (a precursor to eNOS cofactor tetrahydrobiopterin (BH4)) supplementation would improve endothelium-dependent vascular relaxation in sedentary animals via modulation of NOS function and mitochondrial activity. Sedentary male Wistar rats were fed ad libitum for a total of 10 weeks. Sepiapterin was administered in diet during the final 5 weeks. Intraperitoneal insulin and glucose tolerance tests (IP-ITT/IP-GTT) were conducted at baseline and endpoint. Aorta was assessed for vasoreactivity and mitochondrial respiration. Insulin tolerance, determined by IP-ITT, significantly improved in rats treated with sepiapterin (p < 0.05, interaction of time and treatment). Acetylcholine- (ACh-) driven vasodilation was significantly greater in aorta from sepiapterin-treated rats as compared with control (76.4% versus 54.9% of phenylephrine contraction at 20 μM ACh, p < 0.05). Sepiapterin treatment resulted in significantly elevated state 3 (9.00 oxygen pmol/sec∗mg versus 8.17 oxygen pmol/sec∗mg, p < 0.05) and 4 (7.28 oxygen pmol/sec∗mg versus 5.86 oxygen pmol/sec∗mg, p < 0.05) aortic mitochondrial respiration with significantly lower respiratory control ratio (p < 0.05) during octanoylcarnitine-driven respiration. Vasodilation and insulin sensitivity were improved through targeting NOS via sepiapterin supplementation.
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9
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Shirkhani S, Marandi SM, Kazeminasab F, Esmaeili M, Ghaedi K, Esfarjani F, Shiralian-Esfahani H, Nasr-Esfahani MH. Comparative studies on the effects of high-fat diet, endurance training and obesity on Ucp1 expression in male C57BL/6 mice. Gene 2018; 676:16-21. [PMID: 30201103 DOI: 10.1016/j.gene.2018.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/04/2018] [Accepted: 07/05/2018] [Indexed: 01/04/2023]
Abstract
BACKGROUND Obesity triggers a variety of severe conditions, therefore deteriorates metabolism rate of adipose tissues and muscles. Uncoupling proteins which are highly stimulated by fatty acids are potential targets for anti-obesity agents through breaking the electron gradient in the mitochondrial matrix and creating imbalances in the electron transport chain, thereby increasing the amount of substrate used to produce energy. Therefore, the aim of present study is assessment of exercise and high fat diet on expression level of Ucp1 subcutaneous white and brown adipose tissues (scWAT & BAT) respectively. METHODS To perform experiments, 48 male C57BL/6 mice were divided to two major groups and fed with high fat diet (HFD) or low fat diet (LFD) during a period of 12 weeks. After the first intervention, each groups was divided into four groups randomly as (HF-EX), (HF-SED), (LF-EX), (LF-SED) [EX: exercise; SED: sedentary] in form of treadmill running for 45 min/day, 5 days/week during 8 weeks. One day after the last practice session, mice were sacrificed and Ucp1 expression was assessed on scWAT & BAT. RESULTS Data indicated a down-regulation in scWAT Ucp1 in obese mice similar to what observed for the expression of Pgc1α. Both, BAT Ucp1 and Pgc1α mRNA decreased significantly in response to obesity and physical activity. Moreover, exercise caused significant decrease in scWAT mitochondrial proteins contradictory to BAT. CONCLUSION Taken together, exercise exerted controversial effects compared with HFD and obesity on expression of Ucp1 and Pgc1α in scWAT dissimilar to BAT tissues, concluding that obesity may cause a resistance to exercise in terms of metabolic demands for scWAT tissue.
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Affiliation(s)
- Samaneh Shirkhani
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran
| | - Sayed Mohammad Marandi
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran.
| | - Fatemeh Kazeminasab
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran
| | - Maryam Esmaeili
- Department of Cellular Biotechnology, Cell Sciences Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Kamran Ghaedi
- Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran; Department of Cellular Biotechnology, Cell Sciences Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
| | - Fahimeh Esfarjani
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran
| | - Hanieh Shiralian-Esfahani
- Department of Cellular Biotechnology, Cell Sciences Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr-Esfahani
- Department of Cellular Biotechnology, Cell Sciences Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
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10
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Wahl MP, Scalzo RL, Regensteiner JG, Reusch JEB. Mechanisms of Aerobic Exercise Impairment in Diabetes: A Narrative Review. Front Endocrinol (Lausanne) 2018; 9:181. [PMID: 29720965 PMCID: PMC5915473 DOI: 10.3389/fendo.2018.00181] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/04/2018] [Indexed: 12/21/2022] Open
Abstract
The prevalence of diabetes in the United States and globally has been rapidly increasing over the last several decades. There are now estimated to be 30.3 million people in the United States and 422 million people worldwide with diabetes. Diabetes is associated with a greatly increased risk of cardiovascular mortality, which is the leading cause of death in adults with diabetes. While exercise training is a cornerstone of diabetes treatment, people with diabetes have well-described aerobic exercise impairments that may create an additional diabetes-specific barrier to adding regular exercise to their lifestyle. Physiologic mechanisms linked to exercise impairment in diabetes include insulin resistance, cardiac abnormalities, mitochondrial function, and the ability of the body to supply oxygen. In this paper, we highlight the abnormalities of exercise in type 2 diabetes as well as potential therapeutic approaches.
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Affiliation(s)
- Matthew P. Wahl
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, CO, United States
- Veterans Administration Eastern Colorado Health Care System, Denver, CO, United States
| | - Rebecca L. Scalzo
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, CO, United States
- Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
| | - Judith G. Regensteiner
- Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
- Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, CO, United States
| | - Jane E. B. Reusch
- Division of Endocrinology, University of Colorado School of Medicine, Aurora, CO, United States
- Veterans Administration Eastern Colorado Health Care System, Denver, CO, United States
- Center for Women’s Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
- *Correspondence: Jane E. B. Reusch,
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Voluntary aerobic exercise increases arterial resilience and mitochondrial health with aging in mice. Aging (Albany NY) 2017; 8:2897-2914. [PMID: 27875805 PMCID: PMC5191877 DOI: 10.18632/aging.101099] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 11/03/2016] [Indexed: 01/13/2023]
Abstract
Mitochondrial dysregulation and associated excessive reactive oxygen species (mtROS) production is a key source of oxidative stress in aging arteries that reduces baseline function and may influence resilience (ability to withstand stress). We hypothesized that voluntary aerobic exercise would increase arterial resilience in old mice. An acute mitochondrial stressor (rotenone) caused greater (further) impairment in peak carotid EDD in old (~27 mo., OC, n=12; -32.5±-10.5%) versus young (~7 mo., YC n=11; -5.4±- 3.7%) control male mice, whereas arteries from young and old exercising (YVR n=10 and OVR n=11, 10-wk voluntary running; -0.8±-2.1% and -8.0±4.9%, respectively) mice were protected. Ex-vivo simulated Western diet (WD, high glucose and palmitate) caused greater impairment in EDD in OC (-28.5±8.6%) versus YC (-16.9±5.2%) and YVR (-15.3±2.3%), whereas OVR (-8.9±3.9%) were more resilient (not different versus YC). Simultaneous ex-vivo treatment with mitochondria-specific antioxidant MitoQ attenuated WD-induced impairments in YC and OC, but not YVR or OVR, suggesting that exercise improved resilience to mtROS-mediated stress. Exercise normalized age-related alterations in aortic mitochondrial protein markers PGC-1α, SIRT-3 and Fis1 and augmented cellular antioxidant and stress response proteins. Our results indicate that arterial aging is accompanied by reduced resilience and mitochondrial health, which are restored by voluntary aerobic exercise.
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12
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Baynard T, Goulopoulou S, Sosnoff RF, Fernhall B, Kanaley JA. Cardiovagal modulation and efficacy of aerobic exercise training in obese individuals. Med Sci Sports Exerc 2017; 46:369-75. [PMID: 23899888 DOI: 10.1249/mss.0b013e3182a66411] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
UNLABELLED Type 2 diabetes (T2D) is associated with poor exercise tolerance and peak aerobic capacity (V˙O2peak) even when compared to obese nondiabetic peers. Exercise training studies have demonstrated improvements in V˙O2peak among patients with T2D, yet there is a large amount of variability in this response. Recent evidence suggests that cardiac autonomic modulation may be an important factor when considering improvements in aerobic capacity. PURPOSE This study aimed to determine the effects of a 16-wk aerobic exercise program on V˙O2peak in obese individuals, with and without T2D, who were classified as having either high or low cardiovagal modulation (HCVM or LCVM) at baseline. METHODS Obese individuals (38 women and 19 men; body mass index = 36.1 kg·m(-2)) were studied in the fasted state. ECG recordings were obtained while seated for 3 min, before and after 4 months of exercise training (4 d·wk(-1), 65% V˙O(2peak)). The ECG recording was analyzed for HR variability in the spectral domain. Groups were split on a marker of CVM (normalized high frequency (HFnu)) at the 50th percentile, as either HCVM or LCVM. RESULTS V˙O(2peak) only increased with exercise training among those classified as having HCVM, regardless of diabetes status (T2D: HCVM = 20.3-22.5 mL·kg(-1)min(-1), LCVM = 24.3-25.0 mL·kg(-1)min(-1); obese nondiabetics: HCVM = 24.5-26.3 mL·kg(-1)min(-1), LCVM = 23.1-23.7 mL·kg(-1)min(-1)) (P < 0.05). No change in V˙O(2peak) was observed for the LCVM group. Changes in weight do not explain the change in V˙O(2peak) among the HCVM group. Glucose tolerance only improved among the LCVM group with T2D. CONCLUSIONS Obese individuals, with or without T2D, when classified as having relatively HCVM before exercise training, have a greater propensity to improve V˙O(2peak) after a 16-wk aerobic training program.
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Affiliation(s)
- Tracy Baynard
- 1Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL; 2Department of Physiology, Georgia Regents University, Augusta, GA; 3Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL; and 4Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO
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13
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Abstract
Cardiovascular disease risk and all-cause mortality are largely predicted by physical fitness. Exercise stimulates vascular mitochondrial biogenesis through endothelial nitric oxide synthase (eNOS), sirtuins, and PPARγ coactivator 1α (PGC-1α), a response absent in diabetes and hypertension. We hypothesized that an agent regulating eNOS in the context of diabetes could reconstitute exercise-mediated signaling to mitochondrial biogenesis. Glucagon-like peptide 1 (GLP-1) stimulates eNOS and blood flow; we used saxagliptin, an inhibitor of GLP-1 degradation, to test whether vascular mitochondrial adaptation to exercise in diabetes could be restored. Goto-Kakizaki (GK) rats, a nonobese, type 2 diabetes model, and Wistar controls were exposed to an 8-day exercise intervention with or without saxagliptin (10 mg·kg−1·d−1). We evaluated the impact of exercise and saxagliptin on mitochondrial proteins and signaling pathways in aorta. Mitochondrial protein expression increased with exercise in the Wistar aorta and decreased or remained unchanged in the GK animals. GK rats treated with saxagliptin plus exercise showed increased expression of mitochondrial complexes, cytochrome c, eNOS, nNOS, PGC-1α, and UCP3 proteins. Notably, a 3-week saxagliptin plus exercise intervention significantly increased running time in the GK rats. These data suggest that saxagliptin restores vascular mitochondrial adaptation to exercise in a diabetic rodent model and may augment the impact of exercise on the vasculature.
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14
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Park SY, Rossman MJ, Gifford JR, Bharath LP, Bauersachs J, Richardson RS, Abel ED, Symons JD, Riehle C. Exercise training improves vascular mitochondrial function. Am J Physiol Heart Circ Physiol 2016; 310:H821-9. [PMID: 26825520 DOI: 10.1152/ajpheart.00751.2015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/25/2016] [Indexed: 12/17/2022]
Abstract
Exercise training is recognized to improve cardiac and skeletal muscle mitochondrial respiratory capacity; however, the impact of chronic exercise on vascular mitochondrial respiratory function is unknown. We hypothesized that exercise training concomitantly increases both vascular mitochondrial respiratory capacity and vascular function. Arteries from both sedentary (SED) and swim-trained (EX, 5 wk) mice were compared in terms of mitochondrial respiratory function, mitochondrial content, markers of mitochondrial biogenesis, redox balance, nitric oxide (NO) signaling, and vessel function. Mitochondrial complex I and complex I + II state 3 respiration and the respiratory control ratio (complex I + II state 3 respiration/complex I state 2 respiration) were greater in vessels from EX relative to SED mice, despite similar levels of arterial citrate synthase activity and mitochondrial DNA content. Furthermore, compared with the SED mice, arteries from EX mice displayed elevated transcript levels of peroxisome proliferative activated receptor-γ coactivator-1α and the downstream targets cytochrome c oxidase subunit IV isoform 1,isocitrate dehydrogenase(Idh)2, and Idh3a, increased manganese superoxide dismutase protein expression, increased endothelial NO synthase phosphorylation (Ser(1177)), and suppressed reactive oxygen species generation (all P< 0.05). Although there were no differences in EX and SED mice concerning endothelium-dependent and endothelium-independent vasorelaxation, phenylephrine-induced vasocontraction was blunted in vessels from EX compared with SED mice, and this effect was normalized by NOS inhibition. These training-induced increases in vascular mitochondrial respiratory capacity and evidence of improved redox balance, which may, at least in part, be attributable to elevated NO bioavailability, have the potential to protect against age- and disease-related challenges to arterial function.
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Affiliation(s)
- Song-Young Park
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Matthew J Rossman
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Leena P Bharath
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah; Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Johann Bauersachs
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah; Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - E Dale Abel
- Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, Utah; and Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - J David Symons
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah; Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Christian Riehle
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany; Division of Endocrinology, Metabolism and Diabetes, and Program in Molecular Medicine, University of Utah School of Medicine, Salt Lake City, Utah; and Fraternal Order of Eagles Diabetes Research Center and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
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15
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Differential Mitochondrial Adaptation in Primary Vascular Smooth Muscle Cells from a Diabetic Rat Model. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:8524267. [PMID: 27034743 PMCID: PMC4737048 DOI: 10.1155/2016/8524267] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/10/2015] [Accepted: 11/19/2015] [Indexed: 02/07/2023]
Abstract
Diabetes affects more than 330 million people worldwide and causes elevated cardiovascular disease risk. Mitochondria are critical for vascular function, generate cellular reactive oxygen species (ROS), and are perturbed by diabetes, representing a novel target for therapeutics. We hypothesized that adaptive mitochondrial plasticity in response to nutrient stress would be impaired in diabetes cellular physiology via a nitric oxide synthase- (NOS-) mediated decrease in mitochondrial function. Primary smooth muscle cells (SMCs) from aorta of the nonobese, insulin resistant rat diabetes model Goto-Kakizaki (GK) and the Wistar control rat were exposed to high glucose (25 mM). At baseline, significantly greater nitric oxide evolution, ROS production, and respiratory control ratio (RCR) were observed in GK SMCs. Upon exposure to high glucose, expression of phosphorylated eNOS, uncoupled respiration, and expression of mitochondrial complexes I, II, III, and V were significantly decreased in GK SMCs (p < 0.05). Mitochondrial superoxide increased with high glucose in Wistar SMCs (p < 0.05) with no change in the GK beyond elevated baseline concentrations. Baseline comparisons show persistent metabolic perturbations in a diabetes phenotype. Overall, nutrient stress in GK SMCs caused a persistent decline in eNOS and mitochondrial function and disrupted mitochondrial plasticity, illustrating eNOS and mitochondria as potential therapeutic targets.
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16
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Abstract
Our translational research group focuses on addressing the problem of exercise defects in diabetes with basic research efforts in cell and rodent models and clinical research efforts in subjects with diabetes mellitus. CREB (cAMP-response-element-binding protein) regulates cellular differentiation of neurons, β-cells, adipocytes and smooth muscle cells; it is also a potent survival factor and an upstream regulator of mitochondrial biogenesis. In diabetes and cardiovascular disease, CREB protein content is decreased in the vascular media, and its regulation in aberrant in β-cells, neurons and cardiomyocytes. Loss of CREB content and function leads to decreased vascular target tissue resilience when exposed to stressors such as metabolic, oxidative or sheer stress. This basic research programme set the stage for our central hypothesis that diabetes-mediated CREB dysfunction predisposes the diabetes disease progression and cardiovascular complications. Our clinical research programme revealed that diabetes mellitus leads to defects in functional exercise capacity. Our group has determined that the defects in exercise correlate with insulin resistance, endothelial dysfunction, decreased cardiac perfusion and diastolic dysfunction, slowed muscle perfusion kinetics, decreased muscle perfusion and slowed oxidative phosphorylation. Combined basic and clinical research has defined the relationship between exercise and vascular function with particular emphasis on how the signalling to CREB and eNOS [endothelial NOS (nitric oxide synthase)] regulates tissue perfusion, mitochondrial dynamics, vascular function and exercise capacity. The present review summarizes our current working hypothesis that restoration of eNOS/NOS dysfunction will restore cellular homoeostasis and permit an optimal tissue response to an exercise training intervention.
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17
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Phillips SA, Mahmoud AM, Brown MD, Haus JM. Exercise interventions and peripheral arterial function: implications for cardio-metabolic disease. Prog Cardiovasc Dis 2014; 57:521-34. [PMID: 25529367 DOI: 10.1016/j.pcad.2014.12.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Physical inactivity is a major risk factor for the development of obesity and other cardiovascular (CV) disease (CVD). Vascular endothelial dysfunction is a key event in the development of CVD and is associated with a sedentary lifestyle in otherwise healthy adults. In addition, vascular endothelial dysfunction may be exacerbated in sedentary individuals who are obese and insulin resistant, since excess body fat is associated with elevated levels of pro-atherogenic inflammatory adipokines and cytokines that reduce the nitric oxide (NO) and other upstream paracrine signaling substances which reduces vascular health. Since blood flow-related shear stress is a major stimulus to NO release from the endothelium, disturbed flow or low shear stress is the likely mechanism by which vascular endothelial function is altered with inactivity. Evidence shows that regular physical exercise has beneficial effects on CVD and the risk factors that promote peripheral arterial function and health. Both aerobic and resistance exercise training are generally believed to improve endothelial function and are commonly recommended for CV health, including the management of obesity, hypertension, and insulin resistance. However, many factors including age, disease status, and race appear to influence these outcomes. Although evidence supporting the health benefits of exercise is compelling, the optimum prescription (volume and intensity) and the exact mechanism underlying the effects of exercise training on arterial function and cardiometabolic risk has yet to be identified. The focus of this review will be on the evidence supporting exercise interventions for peripheral arterial function.
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Affiliation(s)
- Shane A Phillips
- Department of Physical Therapy, University of Illinois at Chicago, Chicago, IL; Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL.
| | - Abeer M Mahmoud
- Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL; Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL
| | - Michael D Brown
- Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL; Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL
| | - Jacob M Haus
- Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL; Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL
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18
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Kim B, Lee H, Kawata K, Park JY. Exercise-mediated wall shear stress increases mitochondrial biogenesis in vascular endothelium. PLoS One 2014; 9:e111409. [PMID: 25375175 PMCID: PMC4222908 DOI: 10.1371/journal.pone.0111409] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 10/02/2014] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Enhancing structural and functional integrity of mitochondria is an emerging therapeutic option against endothelial dysfunction. In this study, we sought to investigate the effect of fluid shear stress on mitochondrial biogenesis and mitochondrial respiratory function in endothelial cells (ECs) using in vitro and in vivo complementary studies. METHODS AND RESULTS Human aortic- or umbilical vein-derived ECs were exposed to laminar shear stress (20 dyne/cm2) for various durations using a cone-and-plate shear apparatus. We observed significant increases in the expression of key genes related to mitochondrial biogenesis and mitochondrial quality control as well as mtDNA content and mitochondrial mass under the shear stress conditions. Mitochondrial respiratory function was enhanced when cells were intermittently exposed to laminar shear stress for 72 hrs. Also, shear-exposed cells showed diminished glycolysis and decreased mitochondrial membrane potential (ΔΨm). Likewise, in in vivo experiments, mice that were subjected to a voluntary wheel running exercise for 5 weeks showed significantly higher mitochondrial content determined by en face staining in the conduit (greater and lesser curvature of the aortic arch and thoracic aorta) and muscle feed (femoral artery) arteries compared to the sedentary control mice. Interestingly, however, the mitochondrial biogenesis was not observed in the mesenteric artery. This region-specific adaptation is likely due to the differential blood flow redistribution during exercise in the different vessel beds. CONCLUSION Taken together, our findings suggest that exercise enhances mitochondrial biogenesis in vascular endothelium through a shear stress-dependent mechanism. Our findings may suggest a novel mitochondrial pathway by which a chronic exercise may be beneficial for vascular function.
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Affiliation(s)
- Boa Kim
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
- Cardiovascular Research Center, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Hojun Lee
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Keisuke Kawata
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Joon-Young Park
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
- Cardiovascular Research Center, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Miller MW, Knaub LA, Olivera-Fragoso LF, Keller AC, Balasubramaniam V, Watson PA, Reusch JEB. Nitric oxide regulates vascular adaptive mitochondrial dynamics. Am J Physiol Heart Circ Physiol 2013; 304:H1624-33. [PMID: 23585138 PMCID: PMC3680775 DOI: 10.1152/ajpheart.00987.2012] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 04/11/2013] [Indexed: 01/06/2023]
Abstract
Cardiovascular disease risk factors, such as diabetes, hypertension, dyslipidemia, obesity, and physical inactivity, are all correlated with impaired endothelial nitric oxide synthase (eNOS) function and decreased nitric oxide (NO) production. NO-mediated regulation of mitochondrial biogenesis has been established in many tissues, yet the role of eNOS in vascular mitochondrial biogenesis and dynamics is unclear. We hypothesized that genetic eNOS deletion and 3-day nitric oxide synthase (NOS) inhibition in rodents would result in impaired mitochondrial biogenesis and defunct fission/fusion and autophagy profiles within the aorta. We observed a significant, eNOS expression-dependent decrease in mitochondrial electron transport chain (ETC) protein subunits from complexes I, II, III, and V in eNOS heterozygotes and eNOS null mice compared with age-matched controls. In response to NOS inhibition with NG-nitro-L-arginine methyl ester (L-NAME) treatment in Sprague Dawley rats, significant decreases were observed in ETC protein subunits from complexes I, III, and IV as well as voltage-dependent anion channel 1. Decreased protein content of upstream regulators of mitochondrial biogenesis, cAMP response element-binding protein and peroxisome proliferator-activated receptor-γ coactivator-1α, were observed in response to 3-day L-NAME treatment. Both genetic eNOS deletion and NOS inhibition resulted in decreased manganese superoxide dismutase protein. L-NAME treatment resulted in significant changes to mitochondrial dynamic protein profiles with decreased fusion, increased fission, and minimally perturbed autophagy. In addition, L-NAME treatment blocked mitochondrial adaptation to an exercise intervention in the aorta. These results suggest that eNOS/NO play a role in basal and adaptive mitochondrial biogenesis in the vasculature and regulation of mitochondrial turnover.
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Affiliation(s)
- Matthew W Miller
- University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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20
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Abstract
Limitations in physical fitness, a consistent finding in individuals with both type I and type 2 diabetes mellitus, correlate strongly with cardiovascular and all-cause mortality. These limitations may significantly contribute to the persistent excess cardiovascular mortality affecting this group. Exercise impairments in VO2 peak and VO2 kinetics manifest early on in diabetes, even with good glycemic control and in the absence of clinically apparent complications. Subclinical cardiac dysfunction is often present but does not fully explain the observed defect in exercise capacity in persons with diabetes. In part, the cardiac limitations are secondary to decreased perfusion with exercise challenge. This is a reversible defect. Similarly, in the skeletal muscle, impairments in nutritive blood flow correlate with slowed (or inefficient) exercise kinetics and decreased exercise capacity. Several correlations highlight the likelihood of endothelial-specific impairments as mediators of exercise dysfunction in diabetes, including insulin resistance, endothelial dysfunction, decreased myocardial perfusion, slowed tissue hemoglobin oxygen saturation, and impairment in mitochondrial function. Both exercise training and therapies targeted at improving insulin sensitivity and endothelial function improve physical fitness in subjects with type 2 diabetes. Optimization of exercise functions in people with diabetes has implications for diabetes prevention and reductions in mortality risk. Understanding the molecular details of endothelial dysfunction in diabetes may provide specific therapeutic targets for the remediation of this defect. Rat models to test this hypothesis are under study.
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Affiliation(s)
- Jane E B Reusch
- Denver VA Medical Center, Clermont Street, Denver, CO 80220, USA.
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