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Ishihara K, Takata K, Mizutani KI. Involvement of an Aberrant Vascular System in Neurodevelopmental, Neuropsychiatric, and Neuro-Degenerative Diseases. LIFE (BASEL, SWITZERLAND) 2023; 13:life13010221. [PMID: 36676170 PMCID: PMC9866034 DOI: 10.3390/life13010221] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/06/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
The vascular system of the prenatal brain is crucial for the development of the central nervous system. Communication between vessels and neural cells is bidirectional, and dysfunctional communication can lead to neurodevelopmental diseases. In the present review, we introduce neurodevelopmental and neuropsychiatric diseases potentially caused by disturbances in the neurovascular system and discuss candidate genes responsible for neurovascular system impairments. In contrast to diseases that can manifest during the developing stage, we have also summarized the disturbances of the neurovascular system in neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. Furthermore, we discussed the role of abnormal vascularization and dysfunctional vessels in the development of neurovascular-related diseases.
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Affiliation(s)
- Keiichi Ishihara
- Department of Pathological Biochemistry, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
- Correspondence: ; Tel.: +81-75-595-4656
| | - Kazuyuki Takata
- Division of Integrated Pharmaceutical Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Ken-ichi Mizutani
- Laboratory of Stem Cell Biology, Graduate School of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 650-8586, Japan
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The Common Single Cause of Chronic Multi-Hormonal Resistance in Oxidative Stress. Antioxidants (Basel) 2022; 12:antiox12010075. [PMID: 36670938 PMCID: PMC9854708 DOI: 10.3390/antiox12010075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/19/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
In diseases with concomitant oxidative stress, chronic multi-hormonal resistances could be detected. The most conspicuous component of these resistances is insulin resistance, but also leptin, erythropoietin, acetylcholine, triiodothyronine and glucagon-like peptide-1 resistances also occur. On the other hand, in oxidative stress, abnormal tyrosines, for instance, meta- and ortho-tyrosine are also produced and incorporated into the proteins through the translational process. In case these modified proteins are components of the intracellular signalling pathways, a hormonal resistance may develop. The above-mentioned hormones, owning overlapping signalling pathways at the insulin receptor substrate, develop an abnormal tyrosine phosphorylation dependent chronic multi-hormonal resistance. A few weeks free of oxidative stress or the use of antioxidant therapy are required to provide a return from this resistance, which return may be further supported by the supplementation of physiological para-tyrosine and by the add-on therapy of a pharmacological dose of glucagon-like peptide-1 receptor agonist, which is able to bypass the critical insulin receptor substrate signalling.
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Davis CM, Lyon-Scott K, Varlamov EV, Zhang WH, Alkayed NJ. Role of Endothelial STAT3 in Cerebrovascular Function and Protection from Ischemic Brain Injury. Int J Mol Sci 2022; 23:12167. [PMID: 36293020 PMCID: PMC9602684 DOI: 10.3390/ijms232012167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/04/2022] [Accepted: 10/08/2022] [Indexed: 02/25/2024] Open
Abstract
STAT3 plays a protective role against ischemic brain injury; however, it is not clear which brain cell type mediates this effect, and by which mechanism. We tested the hypothesis that endothelial STAT3 contributes to protection from cerebral ischemia, by preserving cerebrovascular endothelial function and blood-brain barrier (BBB) integrity. The objective of this study was to determine the role of STAT3 in cerebrovascular endothelial cell (EC) survival and function, and its role in tissue outcome after cerebral ischemia. We found that in primary mouse brain microvascular ECs, STAT3 was constitutively active, and its phosphorylation was reduced by oxygen-glucose deprivation (OGD), recovering after re-oxygenation. STAT3 inhibition, using two mechanistically different pharmacological inhibitors, increased EC injury after OGD. The sub-lethal inhibition of STAT3 caused endothelial dysfunction, demonstrated by reduced nitric oxide release in response to acetylcholine and reduced barrier function of the endothelial monolayer. Finally, mice with reduced endothelial STAT3 (Tie2-Cre; STAT3flox/wt) sustained larger brain infarcts after middle cerebral artery occlusion (MCAO) compared to wild-type (WT) littermates. We conclude that STAT3 is vital to maintaining cerebrovascular integrity, playing a role in EC survival and function, and protection against cerebral ischemia. Endothelial STAT3 may serve as a potential target in preventing endothelial dysfunction after stroke.
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Affiliation(s)
- Catherine M. Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Kristin Lyon-Scott
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Elena V. Varlamov
- Department of Medicine, Division of Endocrinology and Department of Neurological Surgery, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Wenri H. Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
| | - Nabil J. Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
- The Knight Cardiovascular Institute, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHN-2, Portland, OR 97239-3098, USA
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Teimouri M, Hosseini H, ArabSadeghabadi Z, Babaei-Khorzoughi R, Gorgani-Firuzjaee S, Meshkani R. The role of protein tyrosine phosphatase 1B (PTP1B) in the pathogenesis of type 2 diabetes mellitus and its complications. J Physiol Biochem 2022; 78:307-322. [PMID: 34988903 DOI: 10.1007/s13105-021-00860-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/16/2021] [Indexed: 01/16/2023]
Abstract
Insulin resistance, the most important characteristic of the type 2 diabetes mellitus (T2DM), is mostly caused by impairment in the insulin receptor (IR) signal transduction pathway. Protein tyrosine phosphatase 1B (PTP1B), one of the main negative regulators of the IR signaling pathway, is broadly expressed in various cells and tissues. PTP1B decreases the phosphorylation of the IR resulting in insulin resistance in various tissues. The evidence for the physiological role of PTP1B in regulation of metabolic pathways came from whole-body PTP1B-knockout mice. Whole-body and tissue-specific PTP1B-knockout mice showed improvement in adiposity, insulin resistance, and glucose tolerance. In addition, the key role of PTP1B in the pathogenesis of T2DM and its complications was further investigated in mice models of PTP1B deficient/overexpression. In recent years, targeting PTP1B using PTP1B inhibitors is being considered an attractive target to treat T2DM. PTP1B inhibitors improve the sensitivity of the insulin receptor and have the ability to cure insulin resistance-related diseases. We herein summarized the biological functions of PTP1B in different tissues in vivo and in vitro. We also describe the effectiveness of potent PTP1B inhibitors as pharmaceutical agents to treat T2DM.
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Affiliation(s)
- Maryam Teimouri
- Department of Clinical Biochemistry, School of Allied Medical Sciences, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Hossein Hosseini
- Department of Clinical Biochemistry, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra ArabSadeghabadi
- Department of Clinical Sciences, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran
| | - Reyhaneh Babaei-Khorzoughi
- Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Sattar Gorgani-Firuzjaee
- Department of Medical Laboratory Sciences, School of Allied Health Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Reza Meshkani
- Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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de Oliveira AM, Fonseca FMF, Reis ST, Viana NI, Oliveira EM, Leiria LO, Leite KRM, Nahas WC, Srougi M, Antunes AA. Physical activity effects on bladder dysfunction in an obese and insulin-resistant murine model. Physiol Rep 2021; 9:e14792. [PMID: 33904660 PMCID: PMC8077148 DOI: 10.14814/phy2.14792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/29/2021] [Accepted: 02/09/2021] [Indexed: 12/02/2022] Open
Abstract
Objective To investigate the role of physical activity in functional and molecular bladder alterations in an obese and insulin‐resistant murine model. Methods Wistar rats were randomized into 1. physical activity and standard diet; 2. physical activity and high‐fat diet; 3. no physical activity and standard diet; and 4. no physical activity and high‐fat diet. Groups 1 and 2 were subjected to a 10‐week swimming protocol. Urodynamic study (UDS) was performed, and the expression of genes in the bladder tissue related to the insulin pathway (IRS1/IRS2/PI3K/AKT/eNOS) was assessed using quantitative real‐time polymerase chain reaction. Results Groups 1 and 2 presented lower body weight gains than groups 3 (213.89 ± 13.77 vs 261.63 ± 34.20 grams (g), p = 0.04) and 4 (209.84 ± 27.40 vs 257.57 ± 32.95 g, p = 0.04), respectively. Group 4 had higher insulin level (6.05 ± 1.79 vs 4.14 ± 1.14 ng/ml, p = 0.038) and higher homeostasis model assessment of insulin resistance (HOMA‐IR) index (1.95 ± 0.73 vs 1.09 ± 0.37, p = 0.006) than group 1. On UDS, group 4 had greater number of micturition (13.6 ± 4.21 vs 6.0 ± 1.82, p = 0.04), higher postvoid pressure (8.06 ± 2.24 vs 5.08 ± 1.23, p = 0.04), lower capacity (0.29 ± 0.18 vs 0.91 ± 0.41 ml, p = 0.008), and lower bladder compliance (0.027 ± 0.014 vs 0.091 ± 0.034 ml/mmHg, p = 0.016) versus group 1. High‐fat diet was related to an underexpression throughout insulin signaling pathway, and physical activity was related to an overexpression of the pathway. Conclusions The insulin signaling pathway may be involved in the pathogenesis of bladder dysfunction related to a high‐fat diet. Physical activity may help to prevent bladder disfunction induced by a high‐fat diet through the insulin pathway.
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Affiliation(s)
- André Matos de Oliveira
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | | | - Sabrina Thalita Reis
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | - Nayara Izabel Viana
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | | | - Luiz Osório Leiria
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil
| | - Katia Ramos Moreira Leite
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | - William Carlos Nahas
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | - Miguel Srougi
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | - Alberto Azoubel Antunes
- Laboratory of Medical Research - LIM 55, Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
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Taguchi K, Kaneko N, Okudaira K, Matsumoto T, Kobayashi T. GLP-1 modulates insulin-induced relaxation response through β-arrestin2 regulation in diabetic mice aortas. Acta Physiol (Oxf) 2021; 231:e13573. [PMID: 33098611 DOI: 10.1111/apha.13573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 12/15/2022]
Abstract
AIMS Diabetes impairs insulin-induced endothelium-dependent relaxation by reducing nitric oxide (NO) production. GLP-1, an incretin hormone, has been shown to prevent the development of endothelial dysfunction. In this study, we hypothesized that GLP-1 would improve the impaired insulin-induced relaxation response in diabetic mice. We also examined the underlying mechanisms. METHODS Using aortic rings from ob/ob mice, an animal model of obesity and type 2 diabetes, and from lean mice, vascular relaxation responses and protein expressions were evaluated using insulin, GLP-1, and pathway-specific inhibitors to elucidate the mechanisms of response. In parallel experiments, β-arrestin2 siRNA-transfected aortas were treated with GLP-1 to evaluate its effects on aortic response pathways. RESULTS When compared to that of untreated ob/ob aortas, GLP-1 increased insulin-induced vasorelaxation and NO production. AMPK inhibition did not alter this vasorelaxation in both GLP-1-treated lean and ob/ob aortas, while Akt inhibition reduced vasorelaxation in both groups, and co-treatment with GLP-1 and insulin caused Akt/eNOS activation. Additionally, GLP-1 decreased GRK2 activity and enhanced β-arrestin2 translocation from the cytosol to membrane in ob/ob aortas. β-Arrestin2 siRNA decreased insulin-induced relaxation both in lean aortas and GLP-1-treated ob/ob aortas. CONCLUSIONS We demonstrated that insulin-induced relaxation is dependent on β-arrestin2 translocation and Akt activation via GLP-1-stimulated GRK2 inactivation in ob/ob aortas. We showed a novel cross-talk between GLP-1-responsive β-arrestin2 and insulin signalling in diabetic aortas.
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Affiliation(s)
- Kumiko Taguchi
- Department of Physiology and Morphology Institute of Medicinal Chemistry Hoshi University Tokyo Japan
| | - Nozomu Kaneko
- Department of Physiology and Morphology Institute of Medicinal Chemistry Hoshi University Tokyo Japan
| | - Kanami Okudaira
- Department of Physiology and Morphology Institute of Medicinal Chemistry Hoshi University Tokyo Japan
| | - Takayuki Matsumoto
- Department of Physiology and Morphology Institute of Medicinal Chemistry Hoshi University Tokyo Japan
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology Institute of Medicinal Chemistry Hoshi University Tokyo Japan
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Nizari S, Wells JA, Carare RO, Romero IA, Hawkes CA. Loss of cholinergic innervation differentially affects eNOS-mediated blood flow, drainage of Aβ and cerebral amyloid angiopathy in the cortex and hippocampus of adult mice. Acta Neuropathol Commun 2021; 9:12. [PMID: 33413694 PMCID: PMC7791879 DOI: 10.1186/s40478-020-01108-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/15/2020] [Indexed: 11/18/2022] Open
Abstract
Vascular dysregulation and cholinergic basal forebrain degeneration are both early pathological events in the development of Alzheimer’s disease (AD). Acetylcholine contributes to localised arterial dilatation and increased cerebral blood flow (CBF) during neurovascular coupling via activation of endothelial nitric oxide synthase (eNOS). Decreased vascular reactivity is suggested to contribute to impaired clearance of β-amyloid (Aβ) along intramural periarterial drainage (IPAD) pathways of the brain, leading to the development of cerebral amyloid angiopathy (CAA). However, the possible relationship between loss of cholinergic innervation, impaired vasoreactivity and reduced clearance of Aβ from the brain has not been previously investigated. In the present study, intracerebroventricular administration of mu-saporin resulted in significant death of cholinergic neurons and fibres in the medial septum, cortex and hippocampus of C57BL/6 mice. Arterial spin labelling MRI revealed a loss of CBF response to stimulation of eNOS by the Rho-kinase inhibitor fasudil hydrochloride in the cortex of denervated mice. By contrast, the hippocampus remained responsive to drug treatment, in association with altered eNOS expression. Fasudil hydrochloride significantly increased IPAD in the hippocampus of both control and saporin-treated mice, while increased clearance from the cortex was only observed in control animals. Administration of mu-saporin in the TetOAPPSweInd mouse model of AD was associated with a significant and selective increase in Aβ40-positive CAA. These findings support the importance of the interrelationship between cholinergic innervation and vascular function in the aetiology and/or progression of CAA and suggest that combined eNOS/cholinergic therapies may improve the efficiency of Aβ removal from the brain and reduce its deposition as CAA.
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Masaki N, Ido Y, Yamada T, Yamashita Y, Toya T, Takase B, Hamburg NM, Adachi T. Endothelial Insulin Resistance of Freshly Isolated Arterial Endothelial Cells From Radial Sheaths in Patients With Suspected Coronary Artery Disease. J Am Heart Assoc 2020; 8:e010816. [PMID: 30885039 PMCID: PMC6475050 DOI: 10.1161/jaha.118.010816] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background Endothelial insulin resistance is insulin‐insensitivity in the vascular endothelium and can be observed in experimental models. This study aimed to investigate endothelial insulin resistance in patients with suspected coronary artery disease. To this end, a novel method of obtaining freshly isolated arterial endothelial cells from a radial catheter sheath was developed. Methods and Results Freshly isolated arterial endothelial cells were retrieved from catheter sheaths placed in radial arteries for coronary angiography (n=69, patient age 64±12 years). The endothelial cells were divided into groups for incubation with or without insulin, vascular endothelial growth factor, or acetylcholine. The intensity of phosphorylated endothelial nitric oxide synthase at Ser1177 (p‐eNOS) was quantified by immunofluorescence microscopy. The percentage increase of insulin‐induced phosphorylated endothelial nitric oxide synthase correlated negatively with derivatives of reactive oxygen metabolites, an oxidative stress test (r=−0.348, n=53, P=0.011), E/E′, an index of left ventricular diastolic dysfunction in Doppler echocardiography (ρ=−0.374, n=49, P=0.008), and log‐transformed brain natriuretic peptide (r=−0.266, n=62, P=0.037). Furthermore, percentage increase of insulin‐induced p‐eNOS was an independent factor for the cardio‐ankle vascular index (standardized coefficient β=−0.293, n=42, P=0.021) in the multivariate regression analysis of adaptive least absolute shrinkage and selection operator. Conclusions Our results suggested that endothelial insulin resistance is associated with oxidative stress, left ventricular diastolic dysfunction, heart failure, and arterial stiffness.
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Affiliation(s)
- Nobuyuki Masaki
- 1 Department of Intensive Care Medicine National Defense Medical College Tokorozawa Japan
| | - Yasuo Ido
- 2 Department of Cardiology National Defense Medical College Tokorozawa Japan
| | - Toshiyuki Yamada
- 3 Department of Cardiovascular Surgery Keio University Graduate School of Medicine Tokyo Japan
| | - Youhei Yamashita
- 2 Department of Cardiology National Defense Medical College Tokorozawa Japan
| | - Takumi Toya
- 2 Department of Cardiology National Defense Medical College Tokorozawa Japan
| | - Bonpei Takase
- 1 Department of Intensive Care Medicine National Defense Medical College Tokorozawa Japan
| | - Naomi M Hamburg
- 4 The Whitaker Cardiovascular Institute Department of Medicine Boston University School of Medicine Boston MA
| | - Takeshi Adachi
- 2 Department of Cardiology National Defense Medical College Tokorozawa Japan
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Li Y, Huang C, Fu W, Zhang H, Lao Y, Zhou H, Tan H, Xu H. Screening of the active fractions from the Coreopsis tinctoria Nutt. Flower on diabetic endothelial protection and determination of the underlying mechanism. JOURNAL OF ETHNOPHARMACOLOGY 2020; 253:112645. [PMID: 32045684 DOI: 10.1016/j.jep.2020.112645] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/06/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The Coreopsis tinctoria Nutt. flower (CTF) has been used traditionally in China for treating hypertension and diabetes as well as reducing body weight and blood fat. However, the vascular protection effect of the CTF has not been studied to date. AIM OF THE STUDY This study aimed to screen and identify bioactive fractions from the CTF with a diabetic endothelial protection effect and to clarify the underlying mechanism. MATERIALS AND METHODS The vascular protection effect of Fraction A was studied in high-fat diet and streptozocin-induced diabetic models. The endothelial protection effect of Fraction A-2 was further studied in an in vitro vascular endothelial dysfunction model induced by high glucose. In a high glucose-induced human umbilical vein endothelial cell (HUVEC) model, Fractions A-2-2 and A-2-3 were screened, and their detailed mechanisms of endothelial protection were studied. Liquid chromatography mass spectrometry (LC-MS) was used to identify the main components in Fractions A-2-2 and A-2-3. RESULTS Fraction A treatment significantly improved the endothelium-dependent vasodilation of the mesenteric artery induced by acetylcholine in diabetic rats. The maximum relaxation was 79.82 ± 2.45% in the control group, 64.36 ± 9.81% in the model group, and 91.87 ± 7.38% in the Fraction A treatment group (P < 0.01). Fraction A treatment also decreased rat tail pressure compared with the model group at the 12th week. The systolic blood pressure was 152.7 5 ± 16.99 mmHg in the control group, 188.50 ± 5.94 mmHg in the model group, and 172.60 ± 14.31 mmHg in the Fraction A treatment group (P < 0.05). The mean blood pressure was 128.50 ± 13.79 mmHg in the control group, 157.00 ± 6.06 mmHg in the model group, and 144.80 ± 11.97 mmHg in the Fraction A treatment group (P < 0.05). In an in vitro vascular endothelium-dependent vasodilation dysfunction model induced by high glucose, Fraction A-2 improved the vasodilation of the mesenteric artery. The maximum relaxation was 82.15 ± 16.24% in the control group, 73.29 ± 14.25% in the model group, and 79.62 ± 13.89% in the Fraction A-2 treatment group (P < 0.05). In a high glucose-induced HUVEC model, Fraction A-2-2 and Fraction A-2-3 upregulated the expression of IRS-1, Akt, and eNOS and increased the levels of p-IRS-1Ser307, p-Akt Ser473, and p-eNOSSer1177 and also decreased the expression of NOX4, TNF-α, IL-6, sVCAM, sICAM, and NF-κB (P < 0.01). With the intervention of AG490 and LY294002, the above effects of Fraction A-2-2 and Fraction A-2-3 were inhibited (P < 0.01). LC-MS data showed that in Fraction A-2-2 and Fraction A-2-3, there were 10 main components: flavanocorepsin; polyphenolic; flavanomarein; isochlorogenic acid A; dicaffeoylquinic acid; coreopsin; marein; coreopsin; luteolin-7-O-glucoside; and 3',5,5',7-tetrahydroxyflavanone-O-hexoside. CONCLUSION The protective effect of the CTF on diabetic endothelial dysfunction may be due to its effect on the JAK2/IRS-1/PI3K/Akt/eNOS pathway and the related oxidative stress and inflammation. The results strongly suggested that Fraction A-2-2 and Fraction A-2-3 were the active fractions from the CTF, and the CTF might be a potential option for the prevention of vascular complications in diabetes.
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Affiliation(s)
- Yajuan Li
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Chaoran Huang
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Wenwei Fu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Yuanzhi Lao
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Hua Zhou
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Hongsheng Tan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China.
| | - Hongxi Xu
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China.
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Shu Q, Chen L, Wu S, Li J, Liu J, Xiao L, Chen R, Liang F. Acupuncture Targeting SIRT1 in the Hypothalamic Arcuate Nucleus Can Improve Obesity in High-Fat-Diet-Induced Rats with Insulin Resistance via an Anorectic Effect. Obes Facts 2020; 13:40-57. [PMID: 31935731 PMCID: PMC7105640 DOI: 10.1159/000503752] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 09/26/2019] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To investigate the anorexigenic and anti-obesity effectiveness of electroacupuncture (EA) on high-fat-diet-induced (HFDI) obese rats with insulin resistance (IR) and to reveal the possible mechanisms of EA affecting SIRT1 (silent mating type information regulation 2 homolog 1) in the central nervous system (CNS). METHODS We divided 60 rats into 6 groups. All interventions, including EA and intracerebroventricular administration, were performed after 8 weeks of model establishment. We tested obesity phenotypes like body weight (BW) gain; food intake; and IR levels including glucose infusion rate, intraperitoneal insulin tolerance test (IPITT), and intraperitoneal glucose tolerance test (IPGTT) during treatment. We detected protein expression and microscopic locations in hypothalamic SIRT1, the transcription factor FOXO1 (forkhead box protein O1), acetylated FOXO1 (Ac-FOXO1), pro-opiomelanocortin (POMC), and neuropeptide Y (NPY) via Western blotting and immunofluorescence, and monitored gene expression by real-time polymerase chain reaction. RESULTS Like the SIRT1 agonist, EA suppressed BW gain and IR levels in obese rats, but this was only partially blocked by the SIRT1 antagonist. EA could upregulate protein expression of hypothalamic SIRT1 and downregulate the acetylation level of FOXO1 in the hypothalamic arcuate nucleus (ARC), which decreased gene expression of NPY and increased that of POMC. The agonist targeted the hypothalamic SIRT1 gene, unlike EA, which targeted posttranscriptional regulation. CONCLUSION EA could improve obesity in HFDI rats with IR via its anorectic effect. This effect targeted posttranscriptional regulation of the SIRT1 gene, which induced upregulation of ARC FOXO1 deacetylation and mediated the gene expression of POMC and NPY.
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Affiliation(s)
- Qing Shu
- Department of Rehabilitation, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
| | - Li Chen
- College of Acupuncture, Moxibustion and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
| | - Song Wu
- College of Acupuncture, Moxibustion and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
| | - Jia Li
- College of Acupuncture, Moxibustion and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
| | - Jianmin Liu
- College of Acupuncture, Moxibustion and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
| | - Ling Xiao
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
- School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, China
| | - Rui Chen
- Department of Traditional Chinese Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fengxia Liang
- College of Acupuncture, Moxibustion and Orthopedics, Hubei University of Chinese Medicine, Wuhan, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan, China
- *Fengxia Liang, Hubei University of Chinese Medicine, 1 Tanhualin, Wuchang District, Wuhan, Hubei 430061 (China), E-Mail , Rui Chen, Department of Traditional Chinese Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Street, Wuhan, Hubei 430022 (China), E-Mail
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Electroacupuncture: A Feasible Sirt1 Promoter Which Modulates Metainflammation in Diet-Induced Obesity Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:5302049. [PMID: 30425749 PMCID: PMC6217753 DOI: 10.1155/2018/5302049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 09/25/2018] [Indexed: 02/08/2023]
Abstract
It is generally accepted that metainflammation, a state of chronic and low-grade inflammation in obesity, plays a great role in metabolic disorder like insulin resistance. To gain further insight into the mechanism of metainflammation and find feasible therapy of obesity, diet-induced obesity (DIO) rats model and Electroacupuncture (EA) treatment were established in this trail. The results indicated that rising Lee's index, hyperlipidemia, insulin resistance, and increasing inflammation factors including NF-κB, TNF-α, and Macrophages 1 were determined in DIO rats while EA is exhibiting an effective intervention. Furthermore, to clarify this phenomenon and provide new recognition of alternative medicine for the treatment of metainflammation, we found that EA activating Sirt1 and Sirt1-dependent deacetylation of histone (H3K9) was the key of modulation. It should be noted that, while possible, the activating of Sirt1 could lead to deacetylation of NF-κB also. In this study, the deacetylation of NF-κB depended on higher level of Sirt1 than H3K9, which suggested that the deacetylation via Sirt1 in metainflammation could be specific and programmed.
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12
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Willson C, Watanabe M, Tsuji-Hosokawa A, Makino A. Pulmonary vascular dysfunction in metabolic syndrome. J Physiol 2018; 597:1121-1141. [PMID: 30125956 DOI: 10.1113/jp275856] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 07/30/2018] [Indexed: 12/20/2022] Open
Abstract
Metabolic syndrome is a critically important precursor to the onset of many diseases, such as cardiovascular disease, and cardiovascular disease is the leading cause of death worldwide. The primary risk factors of metabolic syndrome include hyperglycaemia, abdominal obesity, dyslipidaemia, and high blood pressure. It has been well documented that metabolic syndrome alters vascular endothelial and smooth muscle cell functions in the heart, brain, kidney and peripheral vessels. However, there is less information available regarding how metabolic syndrome can affect pulmonary vascular function and ultimately increase an individual's risk of developing various pulmonary vascular diseases, such as pulmonary hypertension. Here, we review in detail how metabolic syndrome affects pulmonary vascular function.
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Affiliation(s)
- Conor Willson
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Makiko Watanabe
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | | | - Ayako Makino
- Department of Physiology, University of Arizona, Tucson, AZ, USA
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13
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Sengupta A, Patel PA, Yuldasheva NY, Mughal RS, Galloway S, Viswambharan H, Walker AMN, Aziz A, Smith J, Ali N, Mercer BN, Imrie H, Sukumar P, Wheatcroft SB, Kearney MT, Cubbon RM. Endothelial Insulin Receptor Restoration Rescues Vascular Function in Male Insulin Receptor Haploinsufficient Mice. Endocrinology 2018; 159:2917-2925. [PMID: 29796592 PMCID: PMC6047419 DOI: 10.1210/en.2018-00215] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/25/2018] [Indexed: 11/19/2022]
Abstract
Reduced systemic insulin signaling promotes endothelial dysfunction and diminished endogenous vascular repair. We investigated whether restoration of endothelial insulin receptor expression could rescue this phenotype. Insulin receptor knockout (IRKO) mice were crossed with mice expressing a human insulin receptor endothelial cell-specific overexpression (hIRECO) to produce IRKO-hIRECO progeny. No metabolic differences were noted between IRKO and IRKO-hIRECO mice in glucose and insulin tolerance tests. In contrast with control IRKO littermates, IRKO-hIRECO mice exhibited normal blood pressure and aortic vasodilatation in response to acetylcholine, comparable to parameters noted in wild type littermates. These phenotypic changes were associated with increased basal- and insulin-stimulated nitric oxide production. IRKO-hIRECO mice also demonstrated normalized endothelial repair after denuding arterial injury, which was associated with rescued endothelial cell migration in vitro but not with changes in circulating progenitor populations or culture-derived myeloid angiogenic cells. These data show that restoration of endothelial insulin receptor expression alone is sufficient to prevent the vascular dysfunction caused by systemically reduced insulin signaling.
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Affiliation(s)
- Anshuman Sengupta
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Peysh A Patel
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Nadira Y Yuldasheva
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Romana S Mughal
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Stacey Galloway
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Hema Viswambharan
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Andrew M N Walker
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Amir Aziz
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Jessica Smith
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Noman Ali
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Ben N Mercer
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Helen Imrie
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Piruthivi Sukumar
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Stephen B Wheatcroft
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Mark T Kearney
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
| | - Richard M Cubbon
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Leeds, United Kingdom
- Correspondence: Richard M. Cubbon, MBChB, PhD, Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, The University of Leeds, Clarendon Way, Leeds, LS2 9JT, United Kingdom. E-mail:
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14
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Saad MJ. Obesity, Diabetes, and Endothelium: Molecular Interactions. ENDOTHELIUM AND CARDIOVASCULAR DISEASES 2018:639-652. [DOI: 10.1016/b978-0-12-812348-5.00044-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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15
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da Silva Franco N, Lubaczeuski C, Guizoni DM, Victorio JA, Santos-Silva JC, Brum PC, Carneiro EM, Davel AP. Propranolol treatment lowers blood pressure, reduces vascular inflammatory markers and improves endothelial function in obese mice. Pharmacol Res 2017; 122:35-45. [DOI: 10.1016/j.phrs.2017.05.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 04/25/2017] [Accepted: 05/17/2017] [Indexed: 12/26/2022]
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16
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Silva JF, Correa IC, Diniz TF, Lima PM, Santos RL, Cortes SF, Coimbra CC, Lemos VS. Obesity, Inflammation, and Exercise Training: Relative Contribution of iNOS and eNOS in the Modulation of Vascular Function in the Mouse Aorta. Front Physiol 2016; 7:386. [PMID: 27656148 PMCID: PMC5013134 DOI: 10.3389/fphys.2016.00386] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/22/2016] [Indexed: 12/27/2022] Open
Abstract
Background: The understanding of obsesity-related vascular dysfunction remains controversial mainly because of the diseases associated with vascular injury. Exercise training is known to prevent vascular dysfunction. Using an obesity model without comorbidities, we aimed at investigating the underlying mechanism of vascular dysfunction and how exercise interferes with this process. Methods: High-sugar diet was used to induce obesity in mice. Exercise training was performed 5 days/week. Body weight, energy intake, and adipose tissues were assessed; blood metabolic and hormonal parameters were determined; and serum TNFα was measured. Blood pressure and heart rate were assessed by plethysmography. Changes in aortic isometric tension were recorded on myograph. Western blot was used to analyze protein expression. Nitric oxide (NO) was evaluated using fluorescence microscopy. Antisense oligodeoxynucleotides were used for inducible nitric oxide synthase isoform (iNOS) knockdown. Results: Body weight, fat mass, total cholesterol, low-density lipoprotein cholesterol fraction, insulin, and leptin were higher in the sedentary obese group (SD) than in the sedentary control animals (SS). Exercise training prevented these changes. No difference in glucose tolerance, insulin sensitivity, blood pressure, and heart rate was found. Decreased vascular relaxation and reduced endothelial nitric oxide synthase (eNOS) functioning in the SD group were prevented by exercise. Contractile response to phenylephrine was decreased in the aortas of the wild SD mice, compared with that of the SS group; however, no alteration was noted in the SD iNOS−/− animals. The decreased contractility was endothelium-dependent, and was reverted by iNOS inhibition or iNOS silencing. The aortas from the SD group showed increased basal NO production, serum TNFα, TNF receptor-1, and phospho-IκB. Exercise training attenuated iNOS-dependent reduction in contractile response in high-sugar diet–fed animals, decreased iNOS expression, and increased eNOS expression. Conclusion: Obesity caused endothelium dysfunction, TNFα, and iNOS pathway up-regulation, decreasing vascular contractility in the obese animals. Exercise training was an effective therapy to control iNOS-dependent NO production and to preserve endothelial function in obese individuals.
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Affiliation(s)
- Josiane F Silva
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Izabella C Correa
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Thiago F Diniz
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Paulo M Lima
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Roger L Santos
- Department of Physiological Science, Universidade Federal do Espírito Santo Espírito Santo, Brazil
| | - Steyner F Cortes
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Cândido C Coimbra
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Virginia S Lemos
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
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Zhou HJ, Wang H, Shu Q, He WJ, Wang YY, Gao Y, Liang FX. Effect of ''Biao-Ben points association'' electro-acupuncture combined with dietary restriction on SIRT1 and UCP1 expression in brown adipose tissue of obese rats. Shijie Huaren Xiaohua Zazhi 2016; 24:3410-3416. [DOI: 10.11569/wcjd.v24.i22.3410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To observe the effect of "Biao-Ben points association" electro-acupuncture combined with dietary control on SIRT1 and UCP1 expression in brown adipose tissue of obese rats.
METHODS: Forty rats with obesity induced with a high-fat diet were randomly divided into four groups, with 10 rats in each group. Rats in the model control group (C) were continued to be given a high-fat diet. Rats in the electro-acupuncture group (E) were treated with "Biao-Ben points association" electro-acupuncture. The dietary restriction group (R) was fed only 70% of high-fat diet to the control group. The electro-acupuncture combined with dietary restriction group (E + R) was treated with both acupuncture and dietary restriction. After 8 wk of treatment, changes of body weight, fasting glucose, insulin, triglycerides, and total cholesterol were recorded. The expression of silent information regulator 1 (SIRT1) and uncoupling protein 1 (UCP1) mRNA was detected in brown adipose tissue.
RESULTS: Compared with the C group, body weight, FPG, FINS, TG, and TC in the other three intervention groups were significantly lower (P < 0.01); these indexes were also significantly lower in the E + R group than in the other two intervention groups (P < 0.05). Compared with the C group, the expression of SIRT1 in the other three intervention groups was significantly higher (P < 0.01). Compared with the C group, the expression of UPC1 mRNA in the other three intervention groups was significantly higher (P < 0.01); UPC1 mRNA expression in the E + R group was also significantly higher than that in the other two intervention groups (P < 0.05).
CONCLUSION: "Biao-Ben points association" electro-acupuncture and dietary restriction might increase the heat production and result in weight loss by promoting the expression of SIRT1 and UCP1 in brown adipose tissue. The anti-obesity effect of "Biao-Ben points association" electro-acupuncture is comparable to that of dietary restriction, and there exist some synergistic effects between them.
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18
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Couto GK, Britto LRG, Mill JG, Rossoni LV. Enhanced nitric oxide bioavailability in coronary arteries prevents the onset of heart failure in rats with myocardial infarction. J Mol Cell Cardiol 2015. [DOI: 10.1016/j.yjmcc.2015.07.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Silva FH, Alexandre EC, Calmasini FB, Calixto MC, Antunes E. Treatment With Metformin Improves Erectile Dysfunction in a Murine Model of Obesity Associated With Insulin Resistance. Urology 2015. [PMID: 26199165 DOI: 10.1016/j.urology.2015.04.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the effects of treatment with metformin on a murine model of obesity-associated erectile dysfunction. MATERIAL AND METHODS C57BL/6 male mice were fed for 10 weeks with standard chow or high-fat diet. Lean and obese mice were treated with the insulin sensitizer metformin (300 mg/kg/day, 2 weeks). Intracavernosal pressure (ICP) and in vitro corpus cavernosum (CC) relaxations to both acetylcholine and electrical field stimulation, as well as phenylephrine-induced contractions, were obtained. Levels of cyclic guanosine monophosphate in CC were detected by enzyme immunoassay. RESULTS High-fat-fed mice exhibited higher body weight and insulin resistance. Cavernous nerve stimulation caused frequency-dependent ICP increases, which were significantly lower in obese compared with lean mice (P <.05). Two-week therapy with metformin reversed the decreased ICP in obese group. The maximal response to acetylcholine in CC was 35% lower (P <.05) in the obese compared to the lean group, which were restored by metformin treatment. Likewise, the impaired electrical field stimulation-induced CC relaxations in obese mice were also partly restored by metformin. Contractile responses to phenylephrine were significantly greater (P <.05) in obese compared to lean mice, which were fully restored by metformin. Basal and stimulated cyclic guanosine monophosphate productions in the erectile tissues were significantly lower (P <.05) in the obese group, an effect fully restored by metformin. CONCLUSION Treatment with metformin restored the erectile function in obese mice, through improvement of in vitro endothelial and nitrergic cavernosal relaxations. Therefore, use of metformin may be a good pharmacologic approach to treat insulin resistance-associated erectile dysfunction.
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Affiliation(s)
- Fábio H Silva
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas, Campinas, Sao Paulo, Brazil.
| | - Eduardo C Alexandre
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas, Campinas, Sao Paulo, Brazil
| | - Fabiano B Calmasini
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas, Campinas, Sao Paulo, Brazil
| | - Marina C Calixto
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas, Campinas, Sao Paulo, Brazil
| | - Edson Antunes
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas, Campinas, Sao Paulo, Brazil
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20
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Velloso LA, Folli F, Saad MJ. TLR4 at the Crossroads of Nutrients, Gut Microbiota, and Metabolic Inflammation. Endocr Rev 2015; 36:245-71. [PMID: 25811237 DOI: 10.1210/er.2014-1100] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Obesity is accompanied by the activation of low-grade inflammatory activity in metabolically relevant tissues. Studies have shown that obesity-associated insulin resistance results from the inflammatory targeting and inhibition of key proteins of the insulin-signaling pathway. At least three apparently distinct mechanisms-endoplasmic reticulum stress, toll-like receptor (TLR) 4 activation, and changes in gut microbiota-have been identified as triggers of obesity-associated metabolic inflammation; thus, they are expected to represent potential targets for the treatment of obesity and its comorbidities. Here, we review the data that place TLR4 in the center of the events that connect the consumption of dietary fats with metabolic inflammation and insulin resistance. Changes in the gut microbiota can lead to reduced integrity of the intestinal barrier, leading to increased leakage of lipopolysaccharides and fatty acids, which can act upon TLR4 to activate systemic inflammation. Fatty acids can also trigger endoplasmic reticulum stress, which can be further stimulated by cross talk with active TLR4. Thus, the current data support a connection among the three main triggers of metabolic inflammation, and TLR4 emerges as a link among all of these mechanisms.
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Affiliation(s)
- Licio A Velloso
- Department of Internal Medicine (L.A.V., F.F., M.J.S.), University of Campinas, 13084-970 Campinas SP, Brazil; and Department of Medicine (F.F.), Division of Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Franco Folli
- Department of Internal Medicine (L.A.V., F.F., M.J.S.), University of Campinas, 13084-970 Campinas SP, Brazil; and Department of Medicine (F.F.), Division of Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Mario J Saad
- Department of Internal Medicine (L.A.V., F.F., M.J.S.), University of Campinas, 13084-970 Campinas SP, Brazil; and Department of Medicine (F.F.), Division of Diabetes, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
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Leiria LOS, Martins MA, Saad MJA. Obesity and asthma: beyond T(H)2 inflammation. Metabolism 2015; 64:172-81. [PMID: 25458831 DOI: 10.1016/j.metabol.2014.10.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 10/01/2014] [Accepted: 10/03/2014] [Indexed: 12/20/2022]
Abstract
Obesity is a major risk factor for asthma. Likewise, obesity is known to increase disease severity in asthmatic subjects and also to impair the efficacy of first-line treatment medications for asthma, worsening asthma control in obese patients. This concept is in agreement with the current understanding that some asthma phenotypes are not accompanied by detectable inflammation, and may not be ameliorated by classical anti-inflammatory therapy. There are growing evidences suggesting that the obesity-related asthma phenotype does not necessarily involve the classical T(H)2-dependent inflammatory process. Hormones involved in glucose homeostasis and in the pathogeneses of obesity likely directly or indirectly link obesity and asthma through inflammatory and non-inflammatory pathways. Furthermore, the endocrine regulation of the airway-related pre-ganglionic nerves likely contributes to airway hyperreactivity (AHR) in obese states. In this review, we focused our efforts on understanding the mechanism underlying obesity-related asthma by exploring the T(H)2-independent mechanisms leading to this disease.
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Affiliation(s)
- Luiz O S Leiria
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Milton A Martins
- Department of Medicine, School of Medicine, University de São Paulo, São Paulo, SP, Brazil
| | - Mário J A Saad
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil.
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22
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Yang Y, Wu Z, Meininger CJ, Wu G. L-Leucine and NO-mediated cardiovascular function. Amino Acids 2015; 47:435-47. [PMID: 25552397 DOI: 10.1007/s00726-014-1904-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/13/2014] [Indexed: 02/06/2023]
Abstract
Reduced availability of nitric oxide (NO) in the vasculature is a major factor contributing to the impaired action of insulin on blood flow and, therefore, insulin resistance in obese and diabetic subjects. Available evidence shows that vascular insulin resistance plays an important role in the pathogenesis of cardiovascular disease, the leading cause of death in developed nations. Interestingly, increased concentrations of L-leucine in the plasma occur in obese humans and other animals with vascular dysfunction. Among branched-chain amino acids, L-leucine is unique in inhibiting NO synthesis from L-arginine in endothelial cells and may modulate cardiovascular homeostasis in insulin resistance. Results of recent studies indicate that L-leucine is an activator of glutamine:fructose-6-phosphate aminotransferase (GFAT), which is the first and a rate-controlling enzyme in the synthesis of glucosamine (an inhibitor of endothelial NO synthesis). Through stimulating the mammalian target of rapamycin signaling pathway and thus protein synthesis, L-leucine may enhance GFAT protein expression, thereby inhibiting NO synthesis in endothelial cells. We propose that reducing circulating levels of L-leucine or endothelial GFAT activity may provide a potentially novel strategy for preventing and/or treating cardiovascular disease in obese and diabetic subjects. Such means may include dietary supplementation with either α-ketoglutarate to enhance the catabolism of L-leucine in the small intestine and other tissues or with N-ethyl-L-glutamine to inhibit GFAT activity in endothelial cells. Preventing leucine-induced activation of GFAT by nutritional supplements or pharmaceutical drugs may contribute to improved cardiovascular function by enhancing vascular NO synthesis.
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Affiliation(s)
- Ying Yang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, People's Republic of China,
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23
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Sansbury BE, Hill BG. Regulation of obesity and insulin resistance by nitric oxide. Free Radic Biol Med 2014; 73:383-99. [PMID: 24878261 PMCID: PMC4112002 DOI: 10.1016/j.freeradbiomed.2014.05.016] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 02/07/2023]
Abstract
Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a worldwide pandemic with few tangible and safe treatment options. Although it is generally accepted that the primary cause of obesity is energy imbalance, i.e., the calories consumed are greater than are utilized, understanding how caloric balance is regulated has proven a challenge. Many "distal" causes of obesity, such as the structural environment, occupation, and social influences, are exceedingly difficult to change or manipulate. Hence, molecular processes and pathways more proximal to the origins of obesity-those that directly regulate energy metabolism or caloric intake-seem to be more feasible targets for therapy. In particular, nitric oxide (NO) is emerging as a central regulator of energy metabolism and body composition. NO bioavailability is decreased in animal models of diet-induced obesity and in obese and insulin-resistant patients, and increasing NO output has remarkable effects on obesity and insulin resistance. This review discusses the role of NO in regulating adiposity and insulin sensitivity and places its modes of action into context with the known causes and consequences of metabolic disease.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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24
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Choi Y, Yoon Y, Lee K, Hien TT, Kang KW, Kim K, Lee J, Lee M, Lee SM, Kang D, Lee B. Uric acid induces endothelial dysfunction by vascular insulin resistance associated with the impairment of nitric oxide synthesis. FASEB J 2014; 28:3197-3204. [DOI: 10.1096/fj.13-247148] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- You‐Jin Choi
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Yujin Yoon
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Kang‐Yo Lee
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Tran Thi Hien
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Keon Wook Kang
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Kyong‐Cheol Kim
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Jeewoo Lee
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Moo‐Yeol Lee
- College of PharmacyDongguk UniversityGoyangRepublic of Korea
| | - Seung Mi Lee
- Department of Obstetrics and GynecologyCollege of MedicineSeoul National UniversitySeoulRepublic of Korea
- Department of Obstetrics and GynecologySeoul Metropolitan Boramae Medical CenterSeoulRepublic of Korea
| | - Duk‐Hee Kang
- Division of NephrologyDepartment of Internal MedicineEwha Womans University School of MedicineSeoulRepublic of Korea
| | - Byung‐Hoon Lee
- College of PharmacySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Pharmaceutical SciencesSeoul National UniversitySeoulRepublic of Korea
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25
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Abstract
The prevalence of obesity has increased remarkably in the past four decades. Because obesity can promote the development of type 2 diabetes and cardiovascular disease, understanding the mechanisms that engender weight gain and discovering safe antiobesity therapies are of critical importance. In particular, the gaseous signaling molecule, nitric oxide (NO), appears to be a central factor regulating adiposity and systemic metabolism. Obese and diabetic states are characterized by a deficit in bioavailable NO, with such decreases commonly attributed to downregulation of endothelial NO synthase (eNOS), loss of eNOS activity, or quenching of NO by its reaction with oxygen radicals. Gain-of-function studies, in which vascular-derived NO has been increased pharmacologically or genetically, reveal remarkable actions of NO on body composition and systemic metabolism. This review addresses the metabolic actions of eNOS and the potential therapeutic utility of harnessing its antiobesogenic effects.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Louisville, Kentucky, USA; Department of Physiology and Biophysics, Louisville, Kentucky, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Louisville, Kentucky, USA; Department of Physiology and Biophysics, Louisville, Kentucky, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, Kentucky, USA.
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26
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Simvastatin treatment increases nitrite levels in obese women: Modulation by T−786C polymorphism of eNOS. Nitric Oxide 2013; 33:83-7. [DOI: 10.1016/j.niox.2013.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/11/2013] [Accepted: 07/14/2013] [Indexed: 11/23/2022]
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Doinseunggitang ameliorates endothelial dysfunction in diabetic atherosclerosis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:783576. [PMID: 24062791 PMCID: PMC3766992 DOI: 10.1155/2013/783576] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 05/23/2013] [Accepted: 05/23/2013] [Indexed: 02/03/2023]
Abstract
Atherosclerosis, a chronic and progressive disease characterized by vascular inflammation, is a leading cause of death in diabetes patients. Doinseunggitang (DYSGT), traditional prescription, has been used for promoting blood circulation to remove blood stasis. The aim of this study was to investigate the beneficial effects of DYSGT on endothelial dysfunction in diabetic atherosclerosis animal model. Apolipoprotein E knockout (ApoE KO) mice fed on a Western diet were treated with DYSGT (200 mg/kg/day). DYSGT significantly lowered blood glucose level and glucose tolerance as well as systolic blood pressure. Metabolic parameter showed that DYSGT markedly decreased triglyceride and LDL-cholesterol levels. In the thoracic aorta, the impairment of vasorelaxation response to acetylcholine and atherosclerotic lesion was attenuated by DYSGT. Furthermore, DYSGT restored the reduction of endothelial nitric oxide synthase (eNOS) expression, leading to the inhibition of intracellular adhesion molecule-1 (ICAM-1) and endothelin-1 (ET-1) expression. In conclusion, DYSGT improved the development of diabetic atherosclerosis via attenuation of the endothelial dysfunction, possibly by inhibiting ET-1, cell adhesion molecules, and lesion formation. Therefore, these results suggest that Korean traditional prescription Doinseunggitang may be useful in the treatment and prevention of diabetic vascular complications.
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Prasai MJ, Mughal RS, Wheatcroft SB, Kearney MT, Grant PJ, Scott EM. Diurnal variation in vascular and metabolic function in diet-induced obesity: divergence of insulin resistance and loss of clock rhythm. Diabetes 2013; 62:1981-9. [PMID: 23382450 PMCID: PMC3661613 DOI: 10.2337/db11-1740] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Circadian rhythms are integral to the normal functioning of numerous physiological processes. Evidence from human and mouse studies suggests that loss of rhythm occurs in obesity and cardiovascular disease and may be a neglected contributor to pathophysiology. Obesity has been shown to impair the circadian clock mechanism in liver and adipose tissue but its effect on cardiovascular tissues is unknown. We investigated the effect of diet-induced obesity in C57BL6J mice upon rhythmic transcription of clock genes and diurnal variation in vascular and metabolic systems. In obesity, clock gene function and physiological rhythms were preserved in the vasculature but clock gene transcription in metabolic tissues and rhythms of glucose tolerance and insulin sensitivity were blunted. The most pronounced attenuation of clock rhythm occurred in adipose tissue, where there was also impairment of clock-controlled master metabolic genes and both AMPK mRNA and protein. Across tissues, clock gene disruption was associated with local inflammation but diverged from impairment of insulin signaling. We conclude that vascular tissues are less sensitive to pathological disruption of diurnal rhythms during obesity than metabolic tissues and suggest that cellular disruption of clock gene rhythmicity may occur by mechanisms shared with inflammation but distinct from those leading to insulin resistance.
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Leiria LO, Sollon C, Báu FR, Mónica FZ, D'Ancona CL, De Nucci G, Grant AD, Anhê GF, Antunes E. Insulin relaxes bladder via PI3K/AKT/eNOS pathway activation in mucosa: unfolded protein response-dependent insulin resistance as a cause of obesity-associated overactive bladder. J Physiol 2013; 591:2259-73. [PMID: 23478138 DOI: 10.1113/jphysiol.2013.251843] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We aimed to investigate the role of insulin in the bladder and its relevance for the development of overactive bladder (OAB) in insulin-resistant obese mice. Bladders from male individuals who were involved in multiple organ donations were used. C57BL6/J mice were fed with a high-fat diet for 10 weeks to induce insulin-resistant obesity. Concentration-response curves to insulin were performed in human and mouse isolated mucosa-intact and mucosa-denuded bladders. Cystometric study was performed in terminally anaesthetized mice. Western blot was performed in bladders to detect phosphorylated endothelial NO synthase (eNOS) (Ser1177) and the phosphorylated protein kinase AKT (Ser473), as well as the unfolded protein response (UPR) markers TRIB3, CHOP and ATF4. Insulin (1-100 nm) produced concentration-dependent mouse and human bladder relaxations that were markedly reduced by mucosal removal or inhibition of the PI3K/AKT/eNOS pathway. In mouse bladders, insulin produced a 3.0-fold increase in cGMP levels (P < 0.05) that was prevented by PI3K/AKT/eNOS pathway inhibition. Phosphoinositide 3-kinase (PI3K) inhibition abolished insulin-induced phosphorylation of AKT and eNOS in bladder mucosa. Obese mice showed greater voiding frequency and non-voiding contractions, indicating overactive detrusor smooth muscle. Insulin failed to relax the bladder or to increase cGMP in the obese group. Insulin-stimulated AKT and eNOS phosphorylation in mucosa was also impaired in obese mice. The UPR markers TRIB3, CHOP and ATF4 were increased in the mucosa of obese mice. The UPR inhibitor 4-phenyl butyric acid normalized all the functional and molecular parameters in obese mice. Our data show that insulin relaxes human and mouse bladder via activation of the PI3K/AKT/eNOS pathway in the bladder mucosa. Endoplasmic reticulum stress-dependent insulin resistance in bladder contributes to OAB in obese mice.
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Affiliation(s)
- Luiz O Leiria
- Department of Pharmacology and Division of Urology, Faculty of Medical Sciences, State University of Campinas, UNICAMP, Campinas São Paulo, Brazil
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Siamwala JH, Dias PM, Majumder S, Joshi MK, Sinkar VP, Banerjee G, Chatterjee S. l-Theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation. J Nutr Biochem 2013; 24:595-605. [DOI: 10.1016/j.jnutbio.2012.02.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 02/23/2012] [Accepted: 02/28/2012] [Indexed: 10/28/2022]
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Ding H, Keller KC, Martinez IKC, Geransar RM, zur Nieden KO, Nishikawa SG, Rancourt DE, zur Nieden NI. NO-β-catenin crosstalk modulates primitive streak formation prior to embryonic stem cell osteogenic differentiation. J Cell Sci 2012; 125:5564-77. [PMID: 22946055 DOI: 10.1242/jcs.081703] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nitric oxide (NO) has been shown to play a crucial role in bone formation in vivo. We sought to determine the temporal effect of NO on murine embryonic stem cells (ESCs) under culture conditions that promote osteogenesis. Expression profiles of NO pathway members and osteoblast-specific markers were analyzed using appropriate assays. We found that NO was supportive of osteogenesis specifically during an early phase of in vitro development (days 3-5). Furthermore, ESCs stably overexpressing the inducible NO synthase showed accelerated and enhanced osteogenesis in vitro and in bone explant cultures. To determine the role of NO in early lineage commitment, a stage in ESC differentiation equivalent to primitive streak formation in vivo, ESCs were transfected with a T-brachyury-GFP reporter. Expression levels of T-brachyury and one of its upstream regulators, β-catenin, the major effector in the canonical Wnt pathway, were responsive to NO levels in differentiating primitive streak-like cells. Our results indicate that NO may be involved in early differentiation through regulation of β-catenin and T-brachyury, controlling the specification of primitive-streak-like cells, which may continue through differentiation to later become osteoblasts.
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Affiliation(s)
- Huawen Ding
- Fraunhofer Institute for Cell Therapy and Immunology, Applied Stem Cell Technologies Unit, 04103 Leipzig, Germany
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Marçal AC, Leonelli M, Fiamoncini J, Deschamps FC, Rodrigues MAM, Curi R, Carpinelli AR, Britto LRG, Carvalho CRO. Diet-induced obesity impairs AKT signalling in the retina and causes retinal degeneration. Cell Biochem Funct 2012; 31:65-74. [PMID: 22915345 DOI: 10.1002/cbf.2861] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 06/18/2012] [Accepted: 07/05/2012] [Indexed: 11/06/2022]
Abstract
Retinopathy, a common complication of diabetes, is characterized by an unbalanced production of nitric oxide (NO), a process regulated by nitric oxide synthase (NOS). We hypothesized that retinopathy might stem from changes in the insulin receptor substrate (IRS)/PI3K/AKT pathway and/or expression of NOS isoforms. Thus, we analysed the morphology and apoptosis index in retinas of obese rats in whom insulin resistance had been induced by a high-fat diet (HFD). Immunoblotting analysis revealed that the retinal tissue of HFD rats had lower levels of AKT(1) , eNOS and nNOS protein than those of samples taken from control animals. Furthermore, immunohistochemical analyses indicated higher levels of iNOS and 4-hydroxynonenal and a larger number of apoptotic nuclei in HFD rats. Finally, both the inner and outer retinal layers of HFD rats were thinner than those in their control counterparts. When considered alongside previous results, these patterns suggest two major ways in which HFD might impact animals: direct activity of ingested fatty acids and/or via insulin-resistance-induced changes in intracellular pathways. We discuss these possibilities in further detail and advocate the use of this animal model for further understanding relationships between retinopathy, metabolic syndrome and type 2 diabetes.
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Affiliation(s)
- Anderson C Marçal
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas (ICB), Universidade de São Paulo (USP), SP, Brazil.
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Lee YJ, Choi DH, Cho GH, Kim JS, Kang DG, Lee HS. Arctium lappa ameliorates endothelial dysfunction in rats fed with high fat/cholesterol diets. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 12:116. [PMID: 22866890 PMCID: PMC3517347 DOI: 10.1186/1472-6882-12-116] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 07/30/2012] [Indexed: 01/04/2023]
Abstract
Background Arctium lappa L. (Asteraceae), burdock, is a medicinal plant that is popularly used for treating hypertension, gout, hepatitis, and other inflammatory disorders. This study was performed to test the effect of ethanol extract of Arctium lappa L. (EAL) seeds on vascular reactivity and inflammatory factors in rats fed a high fat/cholesterol diet (HFCD). Method EAL-I (100 mg·kg−1/day), EAL-II (200 mg·kg−1/day), and fluvastatin (3 mg·kg−1/day) groups initially received HFCD alone for 8 weeks, with EAL supplementation provided during the final 6 weeks. Results Treatment with low or high doses of EAL markedly attenuated plasma levels of triglycerides and augmented plasma levels of high-density lipoprotein (HDL) in HFCD-fed rats. Chronic treatment with EAL markedly reduced impairments of acetylcholine (ACh)-induced relaxation of aortic rings. Furthermore, chronic treatment with EAL significantly lowered systolic blood pressure (SBP) and maintained smooth and flexible intimal endothelial layers in HFCD-fed rats. Chronic treatment with EAL suppressed upregulation of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin in the aorta. Chronic treatment with EAL also suppressed increases in matrix metalloproteinase (MMP)-2 expression. These results suggested that EAL can inhibit HFCD-induced vascular inflammation in the rat model. Conclusion The present study provides evidence that EAL ameliorates HFCD-induced vascular dysfunction through protection of vascular relaxation and suppression of vascular inflammation.
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Choi DH, Lee YJ, Kim JS, Kang DG, Lee HS. Cynanchum wilfordii ameliorates hypertension and endothelial dysfunction in rats fed with high fat/cholesterol diets. Immunopharmacol Immunotoxicol 2012; 34:4-11. [PMID: 22176675 DOI: 10.3109/08923973.2011.569889] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Hypercholesterolemia increases the incidence of atherosclerosis and its pathologic complications. This study was performed to test the effect of an ethanol extract of Cynanchum wilfordii (ECW) on vascular dysfunction in rats fed with high fat/cholesterol diets (HFCD). Male rats were fed a HFCD consisting of 7.5% cocoa butter and 1.25% cholesterol, with or without 100, 200 mg/day/kg ECW. Rats fed with HFCD increased body weight associated with an increase in plasma low-density lipoprotein (LDL) cholesterol level. Chronic ECW treatment in HFCD-fed rats lessened LDL cholesterol and triglyceride levels as well as elevated high-density lipoprotein (HDL) cholesterol. Chronic ECW treatment recovered the HFCD-induced increase in systolic blood pressure, maintained smooth and soft intima endothelial layers by the decrease of intima-media thickness. ECW significantly recovered the diet-induced decrease in vasorelaxation to acetylcholine, high-dose ECW apparently increased vasorelaxation response to sodium nitroprusside in rats fed with HFCD. ECW clearly restored the HFCD-induced reduction in endothelial nitric oxide (NO) synthase expression and Akt expression levels in aortic tissue, leading to improve endothelial function through an increase in endothelium-derived NO production. Furthermore, treatment of ECW significantly recovered the HFCD-induced decrease in aortic cGMP levels in rats. These findings suggest that ECW ameliorates hypertension and endothelial dysfunction via improvement of NO/cGMP signaling pathway in aortic tissue of rats fed with HFCD, suggesting a vascular protective role for this herb in the treatment and prevention of atherosclerotic vascular disease.
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Affiliation(s)
- Deok Ho Choi
- College of Oriental Medicine and Professional Graduate School of Oriental Medicine, Wonkwang University, Shinyong-dong, Iksan, Jeonbuk, Republic of Korea
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Haines RJ, Corbin KD, Pendleton LC, Meininger CJ, Eichler DC. Insulin transcriptionally regulates argininosuccinate synthase to maintain vascular endothelial function. Biochem Biophys Res Commun 2012; 421:9-14. [PMID: 22452988 DOI: 10.1016/j.bbrc.2012.03.074] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 03/13/2012] [Indexed: 11/15/2022]
Abstract
Diminished vascular endothelial cell nitric oxide (NO) production is a major factor in the complex pathogenesis of diabetes mellitus. In this report, we demonstrate that insulin not only maintains endothelial NO production through regulation of endothelial nitric oxide synthase (eNOS), but also via the regulation of argininosuccinate synthase (AS), which is the rate-limiting step of the citrulline-NO cycle. Using serum starved, cultured vascular endothelial cells, we show that insulin up-regulates AS and eNOS transcription to support NO production. Moreover, we show that insulin enhances NO production in response to physiological cues such as bradykinin. To translate these results to an in vivo model, we show that AS transcription is diminished in coronary endothelial cells isolated from rats with streptozotocin (STZ)-induced diabetes. Importantly, we demonstrate restoration of AS and eNOS transcription by insulin treatment in STZ-diabetic rats, and show that this restoration was accompanied by improved endothelial function as measured by endothelium-dependent vasorelaxation. Overall, this report demonstrates, both in cell culture and whole animal studies, that insulin maintains vascular function, in part, through the maintenance of AS transcription, thus ensuring an adequate supply of arginine to maintain vascular endothelial response to physiological cues.
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Affiliation(s)
- Ricci J Haines
- Department of Molecular Medicine, University of South Florida, Morsani College of Medicine, Tampa, FL, USA
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Davel AP, Wenceslau CF, Akamine EH, Xavier FE, Couto GK, Oliveira HT, Rossoni LV. Endothelial dysfunction in cardiovascular and endocrine-metabolic diseases: an update. Braz J Med Biol Res 2011; 44:920-32. [PMID: 21956535 DOI: 10.1590/s0100-879x2011007500104] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 08/01/2011] [Indexed: 11/22/2022] Open
Abstract
The endothelium plays a vital role in maintaining circulatory homeostasis by the release of relaxing and contracting factors. Any change in this balance may result in a process known as endothelial dysfunction that leads to impaired control of vascular tone and contributes to the pathogenesis of some cardiovascular and endocrine/metabolic diseases. Reduced endothelium-derived nitric oxide (NO) bioavailability and increased production of thromboxane A2, prostaglandin H2 and superoxide anion in conductance and resistance arteries are commonly associated with endothelial dysfunction in hypertensive, diabetic and obese animals, resulting in reduced endothelium-dependent vasodilatation and in increased vasoconstrictor responses. In addition, recent studies have demonstrated the role of enhanced overactivation of β-adrenergic receptors inducing vascular cytokine production and endothelial NO synthase (eNOS) uncoupling that seem to be the mechanisms underlying endothelial dysfunction in hypertension, heart failure and in endocrine-metabolic disorders. However, some adaptive mechanisms can occur in the initial stages of hypertension, such as increased NO production by eNOS. The present review focuses on the role of NO bioavailability, eNOS uncoupling, cyclooxygenase-derived products and pro-inflammatory factors on the endothelial dysfunction that occurs in hypertension, sympathetic hyperactivity, diabetes mellitus, and obesity. These are cardiovascular and endocrine-metabolic diseases of high incidence and mortality around the world, especially in developing countries and endothelial dysfunction contributes to triggering, maintenance and worsening of these pathological situations.
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Affiliation(s)
- A P Davel
- Departamento de Anatomia, Biologia Celular e Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, SP, Brasil
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Jung C, Gené GG, Tomás M, Plata C, Selent J, Pastor M, Fandos C, Senti M, Lucas G, Elosua R, Valverde MA. A gain-of-function SNP in TRPC4 cation channel protects against myocardial infarction. Cardiovasc Res 2011; 91:465-71. [PMID: 21427121 DOI: 10.1093/cvr/cvr083] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The TRPC4 non-selective cation channel is widely expressed in the endothelium, where it generates Ca(2+) signals that participate in the endothelium-mediated vasodilatory response. This study sought to identify single-nucleotide polymorphisms (SNPs) in the TRPC4 gene that are associated with myocardial infarction (MI). METHODS AND RESULTS Our candidate-gene association studies identified a missense SNP (TRPC4-I957V) associated with a reduced risk of MI in diabetic patients [odds ratio (OR) = 0.61; confidence interval (CI), 0.40-0.95, P= 0.02]. TRPC4 was also associated with MI in the Wellcome Trust Case-Control Consortium's genome-wide data: an intronic SNP (rs7319926) within the same linkage disequilibrium block as TRPC4-I957V showed an OR of 0.86 (CI, 0.81-0.94; P =10(-4)). Functional studies of the missense SNP were carried out in HEK293 and CHO cells expressing wild-type or mutant channels. Patch-clamp studies and measurement of intracellular [Ca(2+)] in response to muscarinic agonists and direct G-protein activation showed increased channel activity in TRPC4-I957V-transfected cells compared with TRPC4-WT. Site-directed mutagenesis and molecular modelling of TRPC4-I957V suggested that the gain of function was due to the presence of a less bulky Val-957. This permits a firmer interaction between the TRPC4 and the catalytic site of the tyrosine kinase that phosphorylates TRPC4 at Tyr-959 and facilitates channel insertion into the plasma membrane. CONCLUSION We provide evidence for the association of a TRPC4 SNP with MI in population-based genetic studies. The higher Ca(2+) signals generated by TRPC4-I957V may ultimately facilitate the generation of endothelium- and nitric oxide-dependent vasorelaxation, thereby explaining its protective effect at the vasculature.
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Affiliation(s)
- Carole Jung
- Laboratory of Molecular Physiology and Channelopathies, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona, C/ Dr. Aiguader 88, Barcelona, Spain
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Wang Y, Wang S, Wier WG, Zhang Q, Jiang H, Li Q, Chen S, Tian Z, Li Y, Yu X, Zhao M, Liu J, Yang J, Zhang J, Zang W. Exercise improves the dilatation function of mesenteric arteries in postmyocardial infarction rats via a PI3K/Akt/eNOS pathway-mediated mechanism. Am J Physiol Heart Circ Physiol 2010; 299:H2097-106. [PMID: 20935150 DOI: 10.1152/ajpheart.00701.2010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myocardial infarction (MI) has been shown to induce endothelial dysfunction in peripheral resistance arteries and thus increase peripheral resistance. This study was designed to investigate the underlying mechanisms of post-MI-related dysfunctional dilatation of peripheral resistance arteries and, furthermore, to examine whether exercise may restore dysfunctional dilatation of peripheral resistance arteries. Adult male Sprague-Dawley rats were divided into three groups: sham-operated, MI, and MI + exercise. Ultrastructure and relaxation function of the mesenteric arteries, as well as phosphatidylinositol-3 kinase (PI3K), Akt kinases (Akt), endothelial nitric oxide synthase (eNOS) activity, and phosphorylation of PI3K, Akt, and eNOS by ACh were determined. Post-MI rats exhibited pronounced ultrastructural changes in mesenteric artery endothelial cells and endothelial dysfunction. In addition, the activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh were significantly attenuated in mesenteric arteries (P < 0.05-0.01). After 8 wk of exercise, not only did endothelial cells appeared more normal in structure, but also ameliorated post-MI-associated mesenteric arterial dysfunction, which were accompanied by elevated activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh (P < 0.05-0.01). Importantly, inhibition of either PI3K or eNOS attenuated exercise-induced restoration of the dilatation function and blocked PI3K, Akt, and eNOS phosphorylation by ACh in the mesenteric arteries. These data demonstrate that MI induces dysfunctional dilation of peripheral resistance arteries by degradation of endothelial structural integrity and attenuating PI3K-Akt-eNOS signaling. Exercise may restore dilatation function of peripheral resistance arteries by protecting endothelial structural integrity and increasing PI3K-Akt-eNOS signaling cascades.
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Affiliation(s)
- Youhua Wang
- Department of Pharmacology, Xi'an Jiaotong University, College of Medicine, Xi'an, China
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Oxidative stress and inflammatory mediators contribute to endothelial dysfunction in high-fat diet-induced obesity in mice. J Hypertens 2010; 28:2111-9. [DOI: 10.1097/hjh.0b013e32833ca68c] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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High-fat diet results in postprandial insulin resistance that involves parasympathetic dysfunction. Br J Nutr 2010; 104:1450-9. [DOI: 10.1017/s0007114510002400] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Different diets have distinct impacts on glucose homoeostasis, for which insulin sensitivity (IS) after a meal (postprandial IS) is highly relevant. Postprandial IS depends upon hepatic parasympathetic activation and glutathione content elevation. We tested the hypothesis that postprandial IS is compromised in high-fat diet (HFD)-induced obesity. Sprague–Dawley rats were fed a standard diet (STD, n 10), 1-week HFD (n 9) or 4-week HFD (n 8). IS was tested in postprandial state using the rapid IS test (RIST) before and after the blockade of the parasympathetic nerves (atropine, 1 mg/kg); parasympathetic-dependent IS was obtained from the difference between control and post-atropine RIST. Fasting IS was also assessed in the STD-fed rats (n 4) and 4-week HFD-fed rats (n 3) using the RIST. Whole-body fat and regional fat pads were heavier in the 1-week HFD-fed rats (79·8 (se 7·9) and 23·7 (se 1·0) g, respectively) or 4-week HFD-fed rats (106·5 (se 6·1) and 30·1 (se 1·4) g, respectively) than in the STD-fed rats (32·5 (se 3·7) and 13·7 (se 1·0) g, respectively; P < 0·001). Fasted-state IS was similar between the groups studied. Postprandial IS was higher in the STD-fed rats (185·8 (se 5·6) mg glucose/kg body weight (bw)) than in both the 1-week HFD-fed rats (108·8 (se 2·9) mg glucose/kg bw; P < 0·001) and 4-week HFD-fed rats (69·3 (se 2·6) mg glucose/kg bw; P < 0·001). Parasympathetic-dependent IS was impaired in both HFD-fed groups (STD, 108·9 (se 3·9) mg glucose/kg bw; 1-week HFD, 38·6 (se 4·2) mg glucose/kg bw; 4-week HFD, 5·4 (se 1·7) mg glucose/kg bw; P < 0·001). Total (postprandial) and parasympathetic-dependent IS correlated negatively with whole-body fat (R2 0·81 and 0·87) and regional adiposity (R2 0·85 and 0·79). In conclusion, fat accumulation induced by HFD is associated with postprandial insulin resistance, but not with fasting insulin resistance. HFD-associated postprandial insulin resistance is largely mediated by impairment of parasympathetic-dependent insulin action, which correlates with adiposity.
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Bunker AK, Arce-Esquivel AA, Rector RS, Booth FW, Ibdah JA, Laughlin MH. Physical activity maintains aortic endothelium-dependent relaxation in the obese type 2 diabetic OLETF rat. Am J Physiol Heart Circ Physiol 2010; 298:H1889-901. [PMID: 20304812 DOI: 10.1152/ajpheart.01252.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that physical activity can attenuate the temporal decline of ACh-induced endothelium-dependent relaxation during type 2 diabetes mellitus progression in the Otsuka Long-Evans Tokushima fatty (OLETF) rat. Sedentary OLETF rats exhibited decreased ACh-induced abdominal aortic endothelium-dependent relaxation from 13 to 20 wk of age (20-35%) and from 13 to 40 wk of age (35-50%). ACh-induced endothelium-dependent relaxation was maintained in the physically active OLETF group and control sedentary Long-Evans Tokushima Otsuka (LETO) group from 13 to 40 wk of age. Aortic pretreatment with N(G)-nitro-l-arginine (l-NNA), indomethacin (Indo), and l-NNA + Indo did not alter the temporal decline in ACh-induced endothelium-dependent relaxation. Temporal changes in the protein expression of SOD isoforms in the aortic endothelium or smooth muscle did not contribute to the temporal decline in ACh-induced endothelium-dependent relaxation in sedentary OLETF rats. A significant increase in the 40-wk-old sedentary LETO and physically active OLETF rat aortic phosphorylated endothelial nitric oxide (p-eNOS)-to-eNOS ratio was observed versus 13- and 20-wk-old rats in each group that was not seen in the 40- versus 13- and 20-wk-old sedentary OLETF rats. These results suggest that temporal changes in the antioxidant system, EDHF, and cycloxygenase metabolite production in sedentary OLETF rat aortas do not contribute to the temporal decline in sedentary OLETF rat aortic ACh-induced endothelium-dependent relaxation seen with type 2 diabetes mellitus progression. We also report that physical activity in conjunction with aging in the OLETF rat results in a temporal increase in the aortic endothelial p-eNOS-to-eNOS ratio that was not seen in sedentary OLETF rats. These results suggest that the sustained aortic ACh-induced endothelium-dependent relaxation in aged physically active OLETF rats may be the result of an increase in active aortic eNOS.
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Affiliation(s)
- Aaron K Bunker
- Dept. of Biomedical Sciences, Univ. of Missouri, E102 Veterinary Medicine Bldg., 1600 E. Rollins Rd., Columbia, MO 65211, USA
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Yoshida LS, Kawada T, Irie K, Yuda Y, Himi T, Ikemoto F, Takano-Ohmuro H. Shikonin Directly Inhibits Nitric Oxide Synthases: Possible Targets That Affect Thoracic Aorta Relaxation Response and Nitric Oxide Release From RAW 264.7 Macrophages. J Pharmacol Sci 2010; 112:343-51. [DOI: 10.1254/jphs.09340fp] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Sartori C, Dessen P, Mathieu C, Monney A, Bloch J, Nicod P, Scherrer U, Duplain H. Melatonin improves glucose homeostasis and endothelial vascular function in high-fat diet-fed insulin-resistant mice. Endocrinology 2009; 150:5311-7. [PMID: 19819971 DOI: 10.1210/en.2009-0425] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Obesity and insulin resistance represent a problem of utmost clinical significance worldwide. Insulin-resistant states are characterized by the inability of insulin to induce proper signal transduction leading to defective glucose uptake in skeletal muscle tissue and impaired insulin-induced vasodilation. In various pathophysiological models, melatonin interacts with crucial molecules of the insulin signaling pathway, but its effects on glucose homeostasis are not known. In a diet-induced mouse model of insulin resistance and normal chow-fed control mice, we sought to assess the effects of an 8-wk oral treatment with melatonin on insulin and glucose tolerance and to understand underlying mechanisms. In high-fat diet-fed mice, but not in normal chow-fed control mice, melatonin significantly improved insulin sensitivity and glucose tolerance, as evidenced by a higher rate of glucose infusion to maintain euglycemia during hyperinsulinemic clamp studies and an attenuated hyperglycemic response to an ip glucose challenge. Regarding underlying mechanisms, we found that melatonin restored insulin-induced vasodilation to skeletal muscle, a major site of glucose utilization. This was due, at least in part, to the improvement of insulin signal transduction in the vasculature, as evidenced by increased insulin-induced phosphorylation of Akt and endoethelial nitric oxide synthase in aortas harvested from melatonin-treated high-fat diet-fed mice. In contrast, melatonin had no effect on the ability of insulin to promote glucose uptake in skeletal muscle tissue in vitro. These data demonstrate for the first time that in a diet-induced rodent model of insulin resistance, melatonin improves glucose homeostasis by restoring the vascular action of insulin.
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Affiliation(s)
- Claudio Sartori
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, CH-1011 Lausanne, Switzerland
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Nacci C, Tarquinio M, De Benedictis L, Mauro A, Zigrino A, Carratù MR, Quon MJ, Montagnani M. Endothelial dysfunction in mice with streptozotocin-induced type 1 diabetes is opposed by compensatory overexpression of cyclooxygenase-2 in the vasculature. Endocrinology 2009; 150:849-61. [PMID: 18845644 PMCID: PMC2646543 DOI: 10.1210/en.2008-1069] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cardiovascular complications of diabetes result from endothelial dysfunction secondary to persistent hyperglycemia. We investigated potential compensatory mechanisms in the vasculature that oppose endothelial dysfunction in diabetes. BALB/c mice were treated with streptozotocin (STZ) to induce type 1 diabetes (T1D). In mesenteric vascular beds (MVBs), isolated ex vivo from mice treated with STZ for 1 wk, dose-dependent vasorelaxation to acetylcholine (ACh) or sodium nitroprusside was comparable with that in age-matched control mice (CTRL). By contrast, MVBs from mice treated with STZ for 8 wk had severely impaired vasodilator responses to ACh consistent with endothelial dysfunction. Pretreatment of MVBs from CTRL mice with nitric oxide synthase inhibitor nearly abolished vasodilation to ACh. In MVB from 1-wk STZ-treated mice, vasodilation to ACh was only partially impaired by L-N(omega)-arginine methyl ester. Thus, vasculature of mice with T1D may have compensatory nitric oxide-independent mechanisms to augment vasodilation to ACh and oppose endothelial dysfunction. Indeed, pretreatment of MVBs isolated from 1-wk STZ-treated mice with NS-398 [selective cyclooxygenase (COX)-2 inhibitor] unmasked endothelial dysfunction not evident in CTRL mice pretreated without or with NS-398. Expression of COX-2 in MVBs, aortic endothelial cells, and aortic vascular smooth muscle cells from STZ-treated mice was significantly increased (vs. CTRL). Moreover, concentrations of the COX-2-dependent vasodilator 6-keto-prostaglandin F-1alpha was elevated in conditioned media from aorta of STZ-treated mice. We conclude that endothelial dysfunction in a mouse model of T1D is opposed by compensatory up-regulation of COX-2 expression and activity in the vasculature that may be relevant to developing novel therapeutic strategies for diabetes and its cardiovascular complications.
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MESH Headings
- Animals
- Cells, Cultured
- Cyclooxygenase 2/metabolism
- Cyclooxygenase 2/physiology
- Cyclooxygenase 2 Inhibitors/pharmacology
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/physiopathology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Male
- Mice
- Mice, Inbred BALB C
- NG-Nitroarginine Methyl Ester/pharmacology
- Nitric Oxide Synthase Type III/metabolism
- Nitrobenzenes/pharmacology
- Oncogene Protein v-akt/metabolism
- Streptozocin
- Sulfonamides/pharmacology
- Up-Regulation/drug effects
- Up-Regulation/physiology
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Affiliation(s)
- Carmela Nacci
- Department of Pharmacology and Human Physiology, University of Bari Medical School, Bari, Italy
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