1
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Nonsurgical treatment of cerebral ischemia associated with ACTA2 cerebral arteriopathy: a case report and literature review. Childs Nerv Syst 2022; 38:1209-1212. [PMID: 34546411 DOI: 10.1007/s00381-021-05360-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/05/2021] [Indexed: 10/20/2022]
Abstract
Mutations in ACTA2 gene can lead to multisystemic smooth muscle dysfunction, including cerebrovascular disease. Treatment strategies for this rare entity remain controversial, and patients are at increasing risk of neurological sequelae. We herein present the case of an 11-year-old boy previously diagnosed with an ACTA2 gene mutation who developed repetitive transient ischemic attacks and treated with bosentan, an oral endothelin receptor antagonist. Magnetic resonance imaging revealed bilateral, periventricular white matter T2 hyperintensities, and magnetic resonance angiography identified several abnormalities including fusiform dilatation in the proximal segments of internal cerebral arteries, together with followed by terminal segmental stenosis. The distal branches showed a markedly straightened course with no increase in lenticulostriate collaterals. Magnetic resonance imaging also revealed an increase in the number and size of large periventricular white matter lesions located in the left frontal lobe with the progression of ischemic symptoms. Instead of revascularization surgery, the administration of bosentan was started due to the high risk of perioperative ischemic sequelae. After bosentan initiation, the patient's repetitive episodes of cerebral ischemia ceased, and there has been no increase in the number of white matter lesions for 7 years. Bosentan might be beneficial for treating cerebral ischemia associated with ACTA2 cerebral arteriopathy by maintaining the dilatation of stenotic vessels and adequate systemic blood flow and should be considered before performing revascularization surgery.
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2
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Wolf V, Abdul Y, Ergul A. Novel Targets and Interventions for Cognitive Complications of Diabetes. Front Physiol 2022; 12:815758. [PMID: 35058808 PMCID: PMC8764363 DOI: 10.3389/fphys.2021.815758] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/08/2021] [Indexed: 01/16/2023] Open
Abstract
Diabetes and cognitive dysfunction, ranging from mild cognitive impairment to dementia, often coexist in individuals over 65 years of age. Vascular contributions to cognitive impairment/dementia (VCID) are the second leading cause of dementias under the umbrella of Alzheimer's disease and related dementias (ADRD). Over half of dementia patients have VCID either as a single pathology or a mixed dementia with AD. While the prevalence of type 2 diabetes in individuals with dementia can be as high as 39% and diabetes increases the risk of cerebrovascular disease and stroke, VCID remains to be one of the less understood and less studied complications of diabetes. We have identified cerebrovascular dysfunction and compromised endothelial integrity leading to decreased cerebral blood flow and iron deposition into the brain, respectively, as targets for intervention for the prevention of VCID in diabetes. This review will focus on targeted therapies that improve endothelial function or remove iron without systemic effects, such as agents delivered intranasally, that may result in actionable and disease-modifying novel treatments in the high-risk diabetic population.
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Affiliation(s)
- Victoria Wolf
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Yasir Abdul
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States,*Correspondence: Yasir Abdul,
| | - Adviye Ergul
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States,Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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3
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Guo Z, Wu X, Fan W. Clarifying the effects of diabetes on the cerebral circulation: Implications for stroke recovery and beyond. Brain Res Bull 2021; 171:67-74. [PMID: 33662495 DOI: 10.1016/j.brainresbull.2021.02.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/21/2021] [Accepted: 02/26/2021] [Indexed: 02/07/2023]
Abstract
Given the sheer increased number of victims per year and the availability of only one effective treatment, acute ischemic stroke (AIS) remains to be one of the most under-treated serious diseases. Diabetes not only increases the incidence of ischemic stroke, but amplifies the ischemic damage, upon which if patients with diabetes suffer from stroke, he/she will confront increased risks of long-term functional deficits. The grim reality makes it a pressing need to intensify efforts at the basic science level to understand how diabetes impairs stroke recovery. This review retrospects the clinical and experimental studies in order to elucidate the detrimental effect of diabetes on cerebrovascular circulation including the major arteries/arterioles, collateral circulation, and neovascularization to shed light on further exploration of novel strategies for cerebral circulation protection before and after AIS in patients with diabetes.
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Affiliation(s)
- Zhihui Guo
- Department of Neurology, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Xuqing Wu
- Department of Neurology, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Wei Fan
- Department of Neurology, Zhongshan Hospital, Fudan University, 200032, Shanghai, China.
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4
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Wang S, Lv W, Zhang H, Liu Y, Li L, Jefferson JR, Guo Y, Li M, Gao W, Fang X, Paul IA, Rajkowska G, Shaffery JP, Mosley TH, Hu X, Liu R, Wang Y, Yu H, Roman RJ, Fan F. Aging exacerbates impairments of cerebral blood flow autoregulation and cognition in diabetic rats. GeroScience 2020; 42:1387-1410. [PMID: 32696219 DOI: 10.1007/s11357-020-00233-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/08/2020] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus (DM) is a leading risk factor for aging-related dementia; however, the underlying mechanisms are not well understood. The present study, utilizing a non-obese T2DN diabetic model, demonstrates that the myogenic response of the middle cerebral artery (MCA) and parenchymal arteriole (PA) and autoregulation of cerebral blood flow (CBF) in the surface and deep cortex were impaired at both young and old ages. The impaired CBF autoregulation was more severe in old than young DM rats, and in the deep than the surface cortex. The myogenic tone of the MCA was enhanced at perfusion pressure in the range of 40-100 mmHg in young DM rats but was reduced at 140-180 mmHg in old DM rats. No change of the myogenic tone of the PA was observed in young DM rats, whereas it was significantly reduced at 30-60 mmHg in old DM rats. Old DM rats had enhanced blood-brain barrier (BBB) leakage and neurodegeneration, reduced vascular density, tight junction, and pericyte coverage on cerebral capillaries in the CA3 region in the hippocampus. Additionally, DM rats displayed impaired functional hyperemia and spatial learning and short- and long-term memory at both young and old ages. Old DM rats had impaired non-spatial short-term memory. These results revealed that impaired CBF autoregulation and enhanced BBB leakage plays an essential role in the pathogenesis of age- and diabetes-related dementia. These findings will lay the foundations for the discovery of anti-diabetic therapies targeting restoring CBF autoregulation to prevent the onset and progression of dementia in elderly DM.
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Affiliation(s)
- Shaoxun Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Wenshan Lv
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.,Department of Endocrinology and Metabolic, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China
| | - Huawei Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Longyang Li
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Joshua R Jefferson
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Ya Guo
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Man Li
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Wenjun Gao
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Ian A Paul
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Grazyna Rajkowska
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - James P Shaffery
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Thomas H Mosley
- Department of Neurology, University of Mississippi Medical Center, Jackson, MS, 39216, USA.,Department of Medicine (Geriatrics), University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Xinlin Hu
- Department of Endocrinology and Metabolic, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China
| | - Ruen Liu
- Department of Neurosurgery, Peking University People's Hospital, Beijing, 100044, China
| | - Yangang Wang
- Department of Endocrinology and Metabolic, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
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5
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Abdul Y, Jamil S, He L, Li W, Ergul A. Endothelin-1 (ET-1) promotes a proinflammatory microglia phenotype in diabetic conditions. Can J Physiol Pharmacol 2020; 98:596-603. [PMID: 32119570 DOI: 10.1139/cjpp-2019-0679] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diabetes increases the risk and severity of cognitive impairment, especially after ischemic stroke. It is also known that the activation of the endothelin (ET) system is associated with cognitive impairment and microglia around the periinfarct area produce ET-1. However, little is known about the effect of ET-1 on microglial polarization, especially under diabetic conditions. We hypothesized that (i) ET-1 activates microglia to the proinflammatory M-1-like phenotype and (ii) hypoxia/ lipopolysaccharide (LPS) activates the microglial ET system and promotes microglial activation towards the M-1 phenotype in diabetic conditions. Microglial cells (C8B4) cultured under normal-glucose (25 mmol/L) conditions and diabetes-mimicking high-glucose (50 mmol/L) conditions for 48 h were stimulated with ET-1, cobalt chloride (200 μmol/L), or LPS (100 ng/mL) for 24 h. PPET-1, ET receptor subtypes, and M1/M2 marker gene mRNA expression were measured by RT-PCR. Secreted ET-1 was measured by ELISA. A high dose of ET-1 (1 μmol/L) increases the mRNA levels of ET receptors and activates the microglia towards the M1 phenotype. Hypoxia or LPS activates the ET system in microglial cells and shifts the microglia towards the M1 phenotype in diabetic conditions. These in vitro observations warrant further investigation into the role of ET-1-mediated activation of proinflammatory microglia in post-stroke cognitive impairment in diabetes.
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Affiliation(s)
- Yasir Abdul
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Ave., Charleston, SC 29425-2503, USA.,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Sarah Jamil
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Ave., Charleston, SC 29425-2503, USA.,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Lianying He
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Ave., Charleston, SC 29425-2503, USA.,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Weiguo Li
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Ave., Charleston, SC 29425-2503, USA.,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | - Adviye Ergul
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 171 Ashley Ave., Charleston, SC 29425-2503, USA.,Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
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Wei J, Qin L, Fu Y, Dai Y, Wen Y, Xu S. Long-term consumption of alcohol exacerbates neural lesions by destroying the functional integrity of the blood–brain barrier. Drug Chem Toxicol 2019; 45:231-238. [DOI: 10.1080/01480545.2019.1681444] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jiangping Wei
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
- Institute of Material Medica, Integration and Transformation for Brain Disorders, CDUTCM, Chengdu, PR China
| | - Lixia Qin
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
- Institute of Material Medica, Integration and Transformation for Brain Disorders, CDUTCM, Chengdu, PR China
| | - Ying Fu
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
- Institute of Material Medica, Integration and Transformation for Brain Disorders, CDUTCM, Chengdu, PR China
| | - Yuan Dai
- Institute of Material Medica, Integration and Transformation for Brain Disorders, CDUTCM, Chengdu, PR China
- School of Health Preservation and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
| | - Yueqiang Wen
- Institute of Material Medica, Integration and Transformation for Brain Disorders, CDUTCM, Chengdu, PR China
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
| | - Shijun Xu
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, PR China
- Institute of Material Medica, Integration and Transformation for Brain Disorders, CDUTCM, Chengdu, PR China
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7
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Feng W, Liu S, Zhang C, Xia Q, Yu T, Zhu D. Comparison of cerebral and cutaneous microvascular dysfunction with the development of type 1 diabetes. Theranostics 2019; 9:5854-5868. [PMID: 31534524 PMCID: PMC6735377 DOI: 10.7150/thno.33738] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/19/2019] [Indexed: 02/07/2023] Open
Abstract
Rationale: Diabetes can lead to cerebral and cutaneous vascular dysfunction. However, it is still unclear how vascular function changes with the development of diabetes and what differences exist between cerebral and cutaneous vascular dysfunction. Thus, it is very important to monitor changes in cerebral and cutaneous vascular function responses in vivo and study their differences during diabetes development. Methods: With the assistance of newly developed skull and skin optical clearing techniques, we monitored the responses of sodium nitroprusside (SNP)- and acetyl choline (ACh)-induced cerebral and cutaneous vascular blood flow and blood oxygen in diabetic mice in vivo during the development of type 1 diabetes (T1D) by combining laser speckle contrast imaging with hyperspectral imaging. We then compared the differences between cerebral and cutaneous vascular responses and explored the reasons for abnormal changes induced in response to different vascular beds. Results: In the early stage of diabetes (T1D-1 week), there were abnormal changes in the cerebral vascular blood flow and blood oxygen responses to SNP and ACh as well as cutaneous vascular blood oxygen. The cutaneous vascular blood flow response also became abnormal from T1D-3 weeks. Additionally, the T1D-induced abnormal blood flow response was associated with changes in vascular myosin light chain phosphorylation and muscarinic acetylcholine receptor M3 levels, and the aberrant blood oxygen response was related to an increase in glycated hemoglobin levels. Conclusion: These results suggest that the abnormal cutaneous vascular blood oxygen response occurred earlier than the blood flow response and therefore has the potential to serve as a good assessment indicator for revealing cerebrovascular dysfunction in the early stage of diabetes.
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Affiliation(s)
- Wei Feng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Shaojun Liu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Chao Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Qing Xia
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Tingting Yu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Dan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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8
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Fouda AY, Fagan SC, Ergul A. Brain Vasculature and Cognition. Arterioscler Thromb Vasc Biol 2019; 39:593-602. [PMID: 30816798 PMCID: PMC6540805 DOI: 10.1161/atvbaha.118.311906] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/15/2019] [Indexed: 12/18/2022]
Abstract
There is a complex interaction between the brain and the cerebral vasculature to meet the metabolic demands of the brain for proper function. Preservation of cerebrovascular function and integrity has a central role in this sophisticated communication within the brain, and any derangements can have deleterious acute and chronic consequences. In almost all forms of cognitive impairment, from mild to Alzheimer disease, there are changes in cerebrovascular function and structure leading to decreased cerebral blood flow, which may initiate or worsen cognitive impairment. In this focused review, we discuss the contribution of 2 major vasoactive pathways to cerebrovascular dysfunction and cognitive impairment in an effort to identify early intervention strategies.
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Affiliation(s)
- Abdelrahman Y. Fouda
- Vascular Biology Center, Augusta University, GA
- Charlie Norwood VA Medical Center Augusta, GA
| | - Susan C. Fagan
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, GA
- Charlie Norwood VA Medical Center Augusta, GA
| | - Adviye Ergul
- Ralph Johnson Veterans Administration Medical Center, Medical University of South Carolina, Charleston, SC
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC
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9
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Li W, Abdul Y, Ward R, Ergul A. Endothelin and diabetic complications: a brain-centric view. Physiol Res 2018; 67:S83-S94. [PMID: 29947530 DOI: 10.33549/physiolres.933833] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The global epidemic of diabetes is of significant concern. Diabetes associated vascular disease signifies the principal cause of morbidity and mortality in diabetic patients. It is also the most rapidly increasing risk factor for cognitive impairment, a silent disease that causes loss of creativity, productivity, and quality of life. Small vessel disease in the cerebral vasculature plays a major role in the pathogenesis of cognitive impairment in diabetes. Endothelin system, including endothelin-1 (ET-1) and the receptors (ET(A) and ET(B)), is a likely candidate that may be involved in many aspects of the diabetes cerebrovascular disease. In this review, we took a brain-centric approach and discussed the role of the ET system in cerebrovascular and cognitive dysfunction in diabetes.
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Affiliation(s)
- W Li
- Charlie Norwood Veterans Affairs Medical Center, Augusta, Georgia, USA, Department of Physiology, Augusta University, Augusta, Georgia, USA.
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10
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ABDUL Y, WARD R, DONG G, ERGUL A. Lipopolysaccharide-Induced Necroptosis of Brain Microvascular Endothelial Cells Can Be Prevented by Inhibition of Endothelin Receptors. Physiol Res 2018; 67:S227-S236. [DOI: 10.33549/physiolres.933842] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Over activation of the endothelin-1 (ET-1) system in disease states contributes to endothelial dysfunction. On the other hand, ET-1 promotes proliferation and survival of endothelial cells. Regulation of programmed cell death (PCD) pathways is critical for cell survival. Recently discovered necroptosis (regulated necrosis) is a pathological PCD mechanism mediated by the activation of toll like receptor 4 (TLR4), which also happens to stimulate ET-1 production in dendritic cells. To establish the effect of ET-1 on PCD and survival of human brain microvascular endothelial cells (BMVECs) under control and inflammatory conditions, BMVECs were treated with ET-1 (10 nM, 100 nM and 1 µM) or lipopolysaccharide (LPS, 100 ng/ml). ET receptors were blocked with bosentan (10 µM). Under normal growth conditions, exogenous ET-1 reduced BMVEC viability and migration at a relatively high concentration (1 µM). This was accompanied with activation of necroptosis and apoptosis marker genes. LPS decreased endogenous ET-1 secretion, increased ETB receptor expression and activated necroptosis. Even though ET-1 levels were low (less than 10 nM levels used under normal growth conditions), blocking of ET receptors with bosentan inhibited the necroptosis pathway and improved the cell migration ability of BMVECs, suggesting that under inflammatory conditions, ET-1 activates PCD pathways in BMVECs even at physiological levels.
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Affiliation(s)
| | | | | | - A. ERGUL
- Department of Physiology, Augusta University, Augusta, GA, USA
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11
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Coucha M, Abdelsaid M, Ward R, Abdul Y, Ergul A. Impact of Metabolic Diseases on Cerebral Circulation: Structural and Functional Consequences. Compr Physiol 2018; 8:773-799. [PMID: 29687902 DOI: 10.1002/cphy.c170019] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Metabolic diseases including obesity, insulin resistance, and diabetes have profound effects on cerebral circulation. These diseases not only affect the architecture of cerebral blood arteries causing adverse remodeling, pathological neovascularization, and vasoregression but also alter the physiology of blood vessels resulting in compromised myogenic reactivity, neurovascular uncoupling, and endothelial dysfunction. Coupled with the disruption of blood brain barrier (BBB) integrity, changes in blood flow and microbleeds into the brain rapidly occur. This overview is organized into sections describing cerebrovascular architecture, physiology, and BBB in these diseases. In each section, we review these properties starting with larger arteries moving into smaller vessels. Where information is available, we review in the order of obesity, insulin resistance, and diabetes. We also tried to include information on biological variables such as the sex of the animal models noted since most of the information summarized was obtained using male animals. © 2018 American Physiological Society. Compr Physiol 8:773-799, 2018.
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Affiliation(s)
- Maha Coucha
- South University, School of Pharmacy, Savannah, Georgia, USA
| | | | - Rebecca Ward
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Yasir Abdul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Adviye Ergul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
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12
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Shi Y, Vanhoutte PM. Macro- and microvascular endothelial dysfunction in diabetes. J Diabetes 2017; 9:434-449. [PMID: 28044409 DOI: 10.1111/1753-0407.12521] [Citation(s) in RCA: 330] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/06/2016] [Accepted: 12/29/2016] [Indexed: 12/12/2022] Open
Abstract
Endothelial cells, as well as their major products nitric oxide (NO) and prostacyclin, play a key role in the regulation of vascular homeostasis. Diabetes mellitus is an important risk factor for cardiovascular disease. Diabetes-induced endothelial dysfunction is a critical and initiating factor in the genesis of diabetic vascular complications. The present review focuses on both large blood vessels and the microvasculature. The endothelial dysfunction in diabetic macrovascular complications is characterized by reduced NO bioavailability, poorly compensated for by increased production of prostacyclin and/or endothelium-dependent hyperpolarizations, and increased production or action of endothelium-derived vasoconstrictors. The endothelial dysfunction of microvascular complications is primarily characterized by decreased release of NO, enhanced oxidative stress, increased production of inflammatory factors, abnormal angiogenesis, and impaired endothelial repair. In addition, non-coding RNAs (microRNAs) have emerged as participating in numerous cellular processes. Thus, this reviews pays special attention to microRNAs and their modulatory role in diabetes-induced vascular dysfunction. Some therapeutic strategies for preventing and restoring diabetic endothelial dysfunction are also highlighted.
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Affiliation(s)
- Yi Shi
- Biomedical Research Centre, Shanghai Key Laboratory of organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai, PR China
| | - Paul M Vanhoutte
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China
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13
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Abdelsaid M, Coucha M, Hafez S, Yasir A, Johnson MH, Ergul A. Enhanced VEGF signalling mediates cerebral neovascularisation via downregulation of guidance protein ROBO4 in a rat model of diabetes. Diabetologia 2017; 60:740-750. [PMID: 28116460 PMCID: PMC5342922 DOI: 10.1007/s00125-017-4214-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 12/31/2016] [Indexed: 01/06/2023]
Abstract
AIMS/HYPOTHESIS Diabetes promotes cerebral neovascularisation via increased vascular endothelial growth factor (VEGF) angiogenic signalling. Roundabout-4 (ROBO4) protein is an endogenous inhibitor of VEGF signalling that stabilises the vasculature. Yet, how diabetes affects ROBO4 function remains unknown. We hypothesised that increased VEGF signalling in diabetes decreases ROBO4 expression and function via binding of ROBO4 with VEGF-activated β3 integrin and that restoration of ROBO4 expression prevents/repairs cerebral neovascularisation in diabetes. METHODS ROBO4 protein expression in a rat model of type 2 diabetes (Goto-Kakizaki [GK] rats) was examined by western blotting and immunohistochemistry. ROBO4 was locally overexpressed in the brain and in primary brain microvascular endothelial cells (BMVECs). GK rats were treated with SKLB1002, a selective VEGF receptor-2 (VEGFR-2) antagonist. Cerebrovascular neovascularisation indices were determined using a FITC vascular space-filling model. Immunoprecipitation was used to determine ROBO4-β3 integrin interaction. RESULTS ROBO4 expression was significantly decreased in the cerebral vasculature as well as in BMVECs in diabetes (p < 0.05). Silencing Robo4 increased the angiogenic properties of control BMVECs (p < 0.05). In vivo and in vitro overexpression of ROBO4 inhibited VEGF-induced angiogenic signalling and increased vessel maturation. Inhibition of VEGF signalling using SKLB1002 increased ROBO4 expression (p < 0.05) and reduced neovascularisation indices (p < 0.05). Furthermore, SKLB1002 significantly decreased ROBO4-β3 integrin interaction in diabetes (p < 0.05). CONCLUSIONS/INTERPRETATION Our study identifies the restoration of ROBO4 and inhibition of VEGF signalling as treatment strategies for diabetes-induced cerebral neovascularisation.
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Affiliation(s)
- Mohammed Abdelsaid
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA, USA.
- Department of Physiology, Augusta University, 1120 15th Street CA-3135, Augusta, GA, 30912, USA.
| | - Maha Coucha
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA, USA
- Department of Physiology, Augusta University, 1120 15th Street CA-3135, Augusta, GA, 30912, USA
| | - Sherif Hafez
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA, USA
- Department of Physiology, Augusta University, 1120 15th Street CA-3135, Augusta, GA, 30912, USA
| | - Abdul Yasir
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA, USA
- Department of Physiology, Augusta University, 1120 15th Street CA-3135, Augusta, GA, 30912, USA
| | | | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA, USA
- Department of Physiology, Augusta University, 1120 15th Street CA-3135, Augusta, GA, 30912, USA
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14
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Hardigan T, Abdul Y, Ergul A. Linagliptin reduces effects of ET-1 and TLR2-mediated cerebrovascular hyperreactivity in diabetes. Life Sci 2016; 159:90-96. [PMID: 26898123 PMCID: PMC4988948 DOI: 10.1016/j.lfs.2016.02.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 12/12/2022]
Abstract
AIMS The anti-hyperglycemic agent linagliptin, a dipeptidyl peptidase-4 inhibitor, has been shown to reduce inflammation and improve endothelial cell function. In this study, we hypothesized that DPP-IV inhibition with linagliptin would improve impaired cerebral blood flow in diabetic rats through improved insulin-induced cerebrovascular relaxation and reversal of pathological cerebrovascular remodeling that subsequently leads to improvement of cognitive function. MAIN METHODS Male type-2 diabetic Goto-Kakizaki (GK) and nondiabetic Wistar rats were treated with linagliptin, and ET-1 plasma levels and dose response curves to ET-1 (0.1-100nM) in basilar arteries were assessed. The impact of TLR2 antagonism on ET-1 mediated basilar contraction and endothelium-dependent relaxation to acetylcholine (ACh, 1nM-1M) in diabetic GK rats was examined with antibody directed against the TLR2 receptor (Santa Cruz, 5μg/mL). The expression of TLR2 in middle cerebral arteries (MCAs) from treated rats and in brain microvascular endothelial cells (BMVEC) treated with 100nM linagliptin was assessed. KEY FINDINGS Linagliptin lowered plasma ET-1 levels in diabetes, and reduced ET-1-induced vascular contraction. TLR2 antagonism in diabetic basilar arteries reduced ET-1-mediated cerebrovascular dysfunction and improved endothelium-dependent vasorelaxation. Linagliptin treatment in the BMVEC was able to reduce TLR2 expression in cells from both diabetic and nondiabetic rats. CONCLUSIONS These results suggest that inhibition of DPPIV using linagliptin improves the ET-1-mediated cerebrovascular dysfunction observed in diabetes through a reduction in ET-1 plasma levels and reduced cerebrovascular hyperreactivity. This effect is potentially a result of linagliptin causing a decrease in endothelial TLR2 expression and a subsequent increase in NO bioavailability.
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Affiliation(s)
- Trevor Hardigan
- Department of Physiology, Augusta University, Augusta, GA, United States
| | - Yasir Abdul
- Department of Physiology, Augusta University, Augusta, GA, United States
| | - Adviye Ergul
- Department of Physiology, Augusta University, Augusta, GA, United States; Charlie Norwood Veterans Administration Medical Center, Augusta, GA, United States.
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15
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Abstract
Antidementive drugs have made Alzheimer's disease a symptomatically treatable condition but have essentially bypassed vascular dementia. The complexity of its pathology, the variable pathognomonic manifestations, the absence of validated biomarkers and the continuum with Alzheimer's disease that makes vascular dementia a comparatively small market are the major contributing factors. This report discusses how drug repurposing can be harnessed to identify new therapeutic opportunities, where such efforts are already yielding promising results, and which ones must be considered failures. Most investigations address obvious aspects cerebral small vessel disease, but some early-stage developments attempt changes in gene expression or modulation of complex biological pathways. A stronger focus on the nature and dynamics of white matter lesions should yield additional molecular targets.
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Affiliation(s)
- Hermann AM Mucke
- HM Pharma Consultancy, Enenkelstrasse 28/32, A-1160 Vienna, Austria
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16
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Hardigan T, Yasir A, Abdelsaid M, Coucha M, El-Shaffey S, Li W, Johnson MH, Ergul A. Linagliptin treatment improves cerebrovascular function and remodeling and restores reduced cerebral perfusion in Type 2 diabetes. Am J Physiol Regul Integr Comp Physiol 2016; 311:R466-77. [PMID: 27357799 DOI: 10.1152/ajpregu.00057.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/24/2016] [Indexed: 12/20/2022]
Abstract
The antihyperglycemic agent linagliptin, a dipeptidyl peptidase-4 (DPP-IV) inhibitor, has been shown to reduce inflammation and improve endothelial cell function. In this study, we hypothesized that DPP-IV inhibition with linagliptin would improve impaired cerebral perfusion in diabetic rats, as well as improve insulin-induced cerebrovascular relaxation and reverse pathological cerebrovascular remodeling. We further postulated that these changes would lead to a subsequent improvement of cognitive function. Male Type-2 diabetic and nondiabetic Goto-Kakizaki rats were treated with linagliptin for 4 wk, and blood glucose and DPP-IV plasma levels were assessed. Cerebral perfusion was assessed after treatment using laser-Doppler imaging, and dose response to insulin (10(-13) M-10(-6) M) in middle cerebral arteries was tested on a pressurized arteriograph. The impact of DPP-IV inhibition on diabetic cerebrovascular remodeling was assessed over a physiologically relevant pressure range, and changes in short-term hippocampus-dependent learning were observed using a novel object recognition test. Linagliptin lowered DPP-IV activity but did not change blood glucose or insulin levels in diabetes. Insulin-mediated vascular relaxation and cerebral perfusion were improved in the diabetic rats with linagliptin treatment. Indices of diabetic vascular remodeling, such as increased cross-sectional area, media thickness, and wall-to-lumen ratio, were also ameliorated; however, improvements in short-term hippocampal-dependent learning were not observed. The present study provides evidence that linagliptin treatment improves cerebrovascular dysfunction and remodeling in a Type 2 model of diabetes independent of glycemic control. This has important implications in diabetic patients who are predisposed to the development of cerebrovascular complications, such as stroke and cognitive impairment.
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Affiliation(s)
- Trevor Hardigan
- Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Abdul Yasir
- Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Mohammed Abdelsaid
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Maha Coucha
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Sally El-Shaffey
- Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Weiguo Li
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
| | - Maribeth H Johnson
- Department of Biostatistics, The Graduate School at Augusta University, Augusta, Georgia
| | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta, Georgia; and
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17
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Yasir A, Hardigan T, Ergul A. Diabetes-mediated middle cerebral artery remodeling is restored by linagliptin: Interaction with the vascular smooth muscle cell endothelin system. Life Sci 2016; 159:76-82. [PMID: 26944436 DOI: 10.1016/j.lfs.2016.02.096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 02/25/2016] [Accepted: 02/29/2016] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Endothelin-1 (ET-1) mediates cerebrovascular remodeling in vascular smooth muscle layer of the middle cerebral arteries (MCA) in type-2 diabetic Goto-Kakizaki (GK) rats. While metformin, oral glucose lowering agent, prevent/restores vascular remodeling and reduce systemic and local ET-1 levels whether this effect was specific to metformin remained unknown. Our working hypotheses were 1) linagliptin, a DPP-IV inhibitor, can reverse diabetes-mediated cerebrovascular remodeling and this is associated with decreased ET-1, and 2) linagliptin prevents the high glucose induced increase in ET-1 and ET receptors in brain vascular smooth muscle cells (bVSMCs). METHODS Diabetic and non-diabetic GK rats were treated with linagliptin (4weeks). MCAs were fixed in buffered 4% paraformaldehyde and used for morphometry. Human bVSMCs incubated in normal glucose (5.5mM)/high glucose (25mM) conditions were treated with the linagliptin (100nM; 24h). ET-1 secretion and ET receptors were measured in media and cell lysate respectively. Immunostaining was performed for ET-A and ET-B receptor. ET receptors were also measured in cells treated with ET-1 (100nM) and linagliptin. RESULTS Linagliptin treatment regressed vascular remodeling of MCAs in diabetic animals but had no effect on blood glucose. bVSMCs in normal/high glucose condition did not show any significant difference in ET-1 secretion or ET-A and ET-B receptor expression. ET-1 treatment in high glucose condition significantly increased the ET-A receptors and this effect was inhibited by linagliptin. CONCLUSIONS Linagliptin is effective in reversing established pathological cerebrovascular remodeling associated with diabetes. Attenuation of the ET system could be a pleiotropic effect of linagliptin that provides vascular protection.
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Affiliation(s)
- Abdul Yasir
- Charlie Norwood Veterans Administration Medical Center, Augusta University, Augusta, Georgia, United States; Department of Physiology, Augusta University, Augusta, Georgia, United States
| | - Trevor Hardigan
- Department of Physiology, Augusta University, Augusta, Georgia, United States
| | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta University, Augusta, Georgia, United States; Department of Physiology, Augusta University, Augusta, Georgia, United States.
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18
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Relationship of endothelin-1 and NLRP3 inflammasome activation in HT22 hippocampal cells in diabetes. Life Sci 2016; 159:97-103. [PMID: 26883974 DOI: 10.1016/j.lfs.2016.02.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 02/09/2016] [Accepted: 02/10/2016] [Indexed: 12/22/2022]
Abstract
Diabetes increases the risk and worsens the progression of cognitive decline. Diabetic rats treated with the dual endothelin receptor antagonist bosentan, have been shown to improve hippocampal-based cognitive deficits. The NLRP3 inflammasome has been implicated in vascular complications of diabetes. We hypothesized that diabetes-mediated increase in endothelin-1 (ET-1) in hippocampal cells causes NLRP3 activation and inflammation. An in vitro model was employed by exposing HT22 hippocampal cells to normal (25mM), low (5.5mM) and high (50mM) glucose conditions with and without palmitate (200μM) in the presence and absence of 10μM bosentan for 24h. NLRP3 activity was measured by western blotting for cryopyrin and caspase-1. ET-1 and IL-1β expression was determined by ELISA. HT22 cells synthesize high levels of ET-1 in normal conditions, which was reduced with palmitate and bosentan as well as low and high glucose conditions. Decreased ET-1 levels were associated with greater activation of NLRP3 and IL-1β in normal glucose. High glucose increased NLRP3 markers and activation compared to normal and low glucose. These data suggest that ET-1 may be protective to neurons. Although endothelin antagonism may be beneficial in improving vascular dysfunction and cognitive impairment, its impact on hippocampal neurons should be further explored.
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19
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Abdelsaid M, Williams R, Hardigan T, Ergul A. Linagliptin attenuates diabetes-induced cerebral pathological neovascularization in a blood glucose-independent manner: Potential role of ET-1. Life Sci 2015; 159:83-89. [PMID: 26631506 DOI: 10.1016/j.lfs.2015.11.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/20/2015] [Accepted: 11/25/2015] [Indexed: 01/01/2023]
Abstract
AIMS We have shown that glycemic control with metformin or endothelin-1 (ET-1) inhibition with bosentan prevents and restores diabetes-mediated cerebral pathological remodeling and neovascularization. Our recent data suggest that linagliptin, a member of the dipeptidyl peptidase-4 inhibitor class of glucose-lowering agents, prevents cerebrovascular remodeling and dysfunction independent of its blood glucose lowering effects. We hypothesized that linagliptin prevents pathological neovascularization via the modulation of the ET-1 system. MATERIALS AND METHODS 24-week old diabetic Goto-Kakizaki and nondiabetic Wistar rats were treated for 4weeks with either vehicle chow or chow containing 166mg/kg linagliptin. At termination, FITC-dextran was injected to visualize the vasculature. Brain sections were imaged by confocal microscopy for vascular density, tortuosity, vascular volume, and surface in both the cortex and striatum. Retinal acellular capillary formation was measured. Brain microvascular endothelial cells (BMVEC) isolated from control or diabetic rats were treated with linagliptin with or without ET-1 dual receptor antagonist and tested for angiogenic properties with cell migration and tube formation assays. KEY FINDING Linagliptin reduced all indices of cerebral neovascularization compared with control rats. In vitro, linagliptin normalized the augmented angiogenic properties of BMVECs isolated from diabetic animals and bosentan reversed this response. Cells from diabetic animals had higher ET-1 and less ETB receptors than in control cells. Linagliptin significantly decreased ET-1 levels and increased ETB receptors. SIGNIFICANCE ET system contributes to pathological neovascularization in diabetes as evidenced by restoration of functional angiogenesis by bosentan treatment and prevention of linagliptin-mediated improvement of angiogenesis in the in vitro model.
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Affiliation(s)
- Mohammed Abdelsaid
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Department of Physiology, Georgia Regents University, Augusta, Georgia.
| | - Raeonda Williams
- Department of Physiology, Georgia Regents University, Augusta, Georgia
| | - Trevor Hardigan
- Department of Physiology, Georgia Regents University, Augusta, Georgia
| | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta, Georgia; Center for Pharmacy and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, Georgia; Department of Physiology, Georgia Regents University, Augusta, Georgia
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20
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Sánchez A, Martínez P, Muñoz M, Benedito S, García-Sacristán A, Hernández M, Prieto D. Endothelin-1 contributes to endothelial dysfunction and enhanced vasoconstriction through augmented superoxide production in penile arteries from insulin-resistant obese rats: role of ET(A) and ET(B) receptors. Br J Pharmacol 2015; 171:5682-95. [PMID: 25091502 DOI: 10.1111/bph.12870] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 07/21/2014] [Accepted: 07/26/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE We assessed whether endothelin-1 (ET-1) inhibits NO and contributes to endothelial dysfunction in penile arteries in a model of insulin resistance-associated erectile dysfunction (ED). EXPERIMENTAL APPROACH Vascular function was assessed in penile arteries, from obese (OZR) and lean (LZR) Zucker rats, mounted in microvascular myographs. Changes in basal and stimulated levels of superoxide (O2 (-) ) were detected by lucigenin-enhanced chemiluminescence and ET receptor expression was determined by immunohistochemistry. KEY RESULTS ET-1 stimulated acute O2 (-) production that was blunted by tempol and the NADPH oxidase inhibitor, apocynin, but markedly enhanced in obese animals. ET-1 inhibited the vasorelaxant effects of ACh and of the NO donor S-nitroso-N-acetyl-DL-penicillamine in arteries from both LZR and OZR. Selective ETA (BQ123) or ETB receptor (BQ788) antagonists reduced both basal and ET-1-stimulated superoxide generation and reversed ET-1-induced inhibition of NO-mediated relaxations in OZR, while only BQ-123 antagonized ET-1 actions in LZR. ET-1-induced vasoconstriction was markedly enhanced by NO synthase blockade and reduced by endothelium removal and apocynin. In endothelium-denuded penile arteries, apocynin blunted augmented ET-1-induced contractions in OZR. Both ETA and ETB receptors were expressed in smooth muscle and the endothelial layer and up-regulated in arteries from OZR. CONCLUSIONS AND IMPLICATIONS ET-1 stimulates ETA -mediated NADPH oxidase-dependent ROS generation, which inhibits endothelial NO bioavailability and contributes to ET-1-induced contraction in healthy penile arteries. Enhanced vascular expression of ETB receptors contributes to augmented ROS production, endothelial dysfunction and increased vasoconstriction in erectile tissue from insulin-resistant obese rats. Hence, antagonism of ETB receptors might improve the ED associated with insulin-resistant states.
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Affiliation(s)
- A Sánchez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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21
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Abdelsaid M, Prakash R, Li W, Coucha M, Hafez S, Johnson MH, Fagan SC, Ergul A. Metformin treatment in the period after stroke prevents nitrative stress and restores angiogenic signaling in the brain in diabetes. Diabetes 2015; 64:1804-17. [PMID: 25524911 PMCID: PMC4407857 DOI: 10.2337/db14-1423] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/11/2014] [Indexed: 12/04/2022]
Abstract
Diabetes impedes vascular repair and causes vasoregression in the brain after stroke, but mechanisms underlying this response are still unclear. We hypothesized that excess peroxynitrite formation in diabetic ischemia/reperfusion (I/R) injury inactivates the p85 subunit of phosphoinositide 3-kinase (PI3K) by nitration and diverts the PI3K-Akt survival signal to the p38-mitogen-activated protein kinase apoptosis pathway. Nitrotyrosine (NY), Akt and p38 activity, p85 nitration, and caspase-3 cleavage were measured in brains from control, diabetic (GK), or metformin-treated GK rats subjected to sham or stroke surgery and in brain microvascular endothelial cells (BMVECs) from Wistar and GK rats subjected to hypoxia/reoxygenation injury. GK rat brains showed increased NY, caspase-3 cleavage, and p38 activation and decreased Akt activation. Metformin attenuated stroke-induced nitrative signaling in GK rats. GK rat BMVECs showed increased basal nitrative stress compared with controls. A second hit by hypoxia/reoxygenation injury dramatically increased the nitration of p85 and activation of p38 but decreased Akt. These effects were associated with impairment of angiogenic response and were restored by treatment with the peroxynitrite scavenger 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron III chloride or the nitration inhibitor epicatechin. Our results provide evidence that I/R-induced peroxynitrite inhibits survival, induces apoptosis, and promotes peroxynitrite as a novel therapeutic target for the improvement of reparative angiogenesis after stroke in diabetes.
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Affiliation(s)
- Mohammed Abdelsaid
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA Department of Physiology, Georgia Regents University, Augusta, GA
| | - Roshini Prakash
- Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA
| | - Weiguo Li
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA Department of Physiology, Georgia Regents University, Augusta, GA
| | - Maha Coucha
- Department of Physiology, Georgia Regents University, Augusta, GA
| | - Sherif Hafez
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA
| | | | - Susan C Fagan
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA
| | - Adviye Ergul
- Charlie Norwood Veterans Administration Medical Center, Augusta, GA Department of Physiology, Georgia Regents University, Augusta, GA Program in Clinical and Experimental Therapeutics, University of Georgia College of Pharmacy, Augusta, GA
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22
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Emoto N, Yanagisawa M. The Thirteenth International Conference on Endothelin (ET-13), Tokyo, 2013. Life Sci 2014; 118:70-6. [DOI: 10.1016/j.lfs.2014.09.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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