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Raman-Nair J, Cron G, MacLeod K, Lacoste B. Sex-Specific Acute Cerebrovascular Responses to Photothrombotic Stroke in Mice. eNeuro 2024; 11:ENEURO.0400-22.2023. [PMID: 38164600 PMCID: PMC10849032 DOI: 10.1523/eneuro.0400-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/11/2023] [Accepted: 11/25/2023] [Indexed: 01/03/2024] Open
Abstract
Mechanisms underlying cerebrovascular stroke outcomes are poorly understood, and the effects of biological sex on cerebrovascular regulation post-stroke have yet to be fully comprehended. Here, we explore the overlapping roles of gonadal sex hormones and rho-kinase (ROCK), two important modulators of cerebrovascular tone, on the acute cerebrovascular response to photothrombotic (PT) focal ischemia in mice. Male mice were gonadectomized and female mice were ovariectomized to remove gonadal hormones, whereas control ("intact") animals received a sham surgery prior to stroke induction. Intact wild-type (WT) males showed a delayed drop in cerebral blood flow (CBF) compared with intact WT females, whereby maximal CBF drop was observed 48 h following stroke. Gonadectomy in males did not alter this response. However, ovariectomy in WT females produced a "male-like" phenotype. Intact Rock2+/- males also showed the same phenotypic response, which was not altered by gonadectomy. Alternatively, intact Rock2+/- females showed a significant difference in CBF values compared with intact WT females, displaying higher CBF values immediately post-stroke and showing a maximal CBF drop 48 h post-stroke. This pattern was not altered by ovariectomy. Altogether, these data illustrate sex differences in acute CBF responses to PT stroke, which seem to involve gonadal female sex hormones and ROCK2. Overall, this study provides a framework for exploring sex differences in acute CBF responses to focal ischemic stroke in mice.
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Affiliation(s)
- Joanna Raman-Nair
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Gregory Cron
- Neurology Department, Stanford University, Stanford 94305, California
| | - Kathleen MacLeod
- Pharmaceutical Sciences, University of British Colombia, Vancouver V6T 1Z3, British Columbia, Canada
| | - Baptiste Lacoste
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Ontario K1H 8L6, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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2
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Wang S, Tang C, Liu Y, Border JJ, Roman RJ, Fan F. Impact of impaired cerebral blood flow autoregulation on cognitive impairment. FRONTIERS IN AGING 2022; 3:1077302. [PMID: 36531742 PMCID: PMC9755178 DOI: 10.3389/fragi.2022.1077302] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 11/23/2022] [Indexed: 11/16/2023]
Abstract
Although the causes of cognitive impairment are multifactorial, emerging evidence indicates that cerebrovascular dysfunction plays an essential role in dementia. One of the most critical aspects of cerebrovascular dysfunction is autoregulation of cerebral blood flow (CBF), mainly mediated by the myogenic response, which is often impaired in dementia individuals with comorbidities, such as diabetes and hypertension. However, many unsolved questions remain. How do cerebrovascular networks coordinately modulate CBF autoregulation in health and disease? Does poor CBF autoregulation have an impact on cognitive impairment, and what are the underlying mechanisms? This review summarizes the cerebral vascular structure and myogenic (a three-phase model), metabolic (O2, CO2, adenosine, and H+), and endothelial (shear stress) factors in the regulation of CBF; and the consequences of CBF dysautoregulation. Other factors contributing to cerebrovascular dysfunction, such as impaired functional hyperemia and capillary abnormalities, are included as well. Moreover, this review highlights recent studies from our lab in terms of novel mechanisms involved in CBF autoregulation and addresses a hypothesis that there is a three-line of defense for CBF autoregulation in the cerebral vasculature.
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Affiliation(s)
- Shaoxun Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Chengyun Tang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Jane J Border
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, United States
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3
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Nieves-Cintrón M, Flores-Tamez VA, Le T, Baudel MMA, Navedo MF. Cellular and molecular effects of hyperglycemia on ion channels in vascular smooth muscle. Cell Mol Life Sci 2021; 78:31-61. [PMID: 32594191 PMCID: PMC7765743 DOI: 10.1007/s00018-020-03582-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 06/10/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022]
Abstract
Diabetes affects millions of people worldwide. This devastating disease dramatically increases the risk of developing cardiovascular disorders. A hallmark metabolic abnormality in diabetes is hyperglycemia, which contributes to the pathogenesis of cardiovascular complications. These cardiovascular complications are, at least in part, related to hyperglycemia-induced molecular and cellular changes in the cells making up blood vessels. Whereas the mechanisms mediating endothelial dysfunction during hyperglycemia have been extensively examined, much less is known about how hyperglycemia impacts vascular smooth muscle function. Vascular smooth muscle function is exquisitely regulated by many ion channels, including several members of the potassium (K+) channel superfamily and voltage-gated L-type Ca2+ channels. Modulation of vascular smooth muscle ion channels function by hyperglycemia is emerging as a key contributor to vascular dysfunction in diabetes. In this review, we summarize the current understanding of how diabetic hyperglycemia modulates the activity of these ion channels in vascular smooth muscle. We examine underlying mechanisms, general properties, and physiological relevance in the context of myogenic tone and vascular reactivity.
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Affiliation(s)
- Madeline Nieves-Cintrón
- Department of Pharmacology, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Víctor A Flores-Tamez
- Department of Pharmacology, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Thanhmai Le
- Department of Pharmacology, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA
| | | | - Manuel F Navedo
- Department of Pharmacology, University of California Davis, One Shields Avenue, Davis, CA, 95616, USA.
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4
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Südy R, Peták F, Kiss L, Balogh ÁL, Fodor GH, Korsós A, Schranc Á, Babik B. Obesity and diabetes: similar respiratory mechanical but different gas exchange defects. Am J Physiol Lung Cell Mol Physiol 2020; 320:L368-L376. [PMID: 33264577 DOI: 10.1152/ajplung.00439.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Diabetes mellitus increases smooth muscle tone and causes tissue remodeling, affecting elastin and collagen. Although the lung is dominated by these elements, diabetes is expected to modify the airway function and respiratory tissue mechanics. Therefore, we characterized the respiratory function in patients with diabetes with and without associated obesity. Mechanically ventilated patients with normal body shapes were divided into the control nondiabetic (n = 73) and diabetic (n = 31) groups. The other two groups included obese patients without diabetes (n = 43) or with diabetes (n = 30). The mechanical properties of the respiratory system were determined by forced oscillation technique. Airway resistance (Raw), tissue damping (G), and tissue elastance (H) were assessed by forced oscillation. Capnography was applied to determine phase 3 slopes and dead space indices. The intrapulmonary shunt fraction (Qs/Qt) and the lung oxygenation index (PaO2/FIO2) were estimated from arterial and central venous blood samples. Compared with the corresponding control groups, diabetes alone increased the Raw (7.6 ± 6 cmH2O.s/l vs. 3.1 ± 1.9 cmH2O.s/l), G (11.7 ± 5.5 cmH2O/l vs. 6.5 ± 2.8 cmH2O/l), and H (31.5 ± 11.8 cmH2O/l vs. 24.2 ± 7.2 cmH2O/l (P < 0.001 for all). Diabetes increased the capnographic phase 3 slope, whereas PaO2/FIO2 or Qs/Qt was not affected. Obesity alone caused similar detrimental changes in respiratory mechanics and alveolar heterogeneity, but these alterations also compromised gas exchange. We conclude that diabetes-induced intrinsic mechanical abnormalities are counterbalanced by hypoxic pulmonary vasoconstriction, which maintained intrapulmonary shunt fraction and oxygenation ability of the lungs.
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Affiliation(s)
- Roberta Südy
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary.,Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Ferenc Peták
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Liliána Kiss
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary.,Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Ádám L Balogh
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary.,Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Gergely H Fodor
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Anita Korsós
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary
| | - Álmos Schranc
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Barna Babik
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary
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5
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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: 39] [Impact Index Per Article: 9.8] [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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6
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De Simone R, Ranieri A, Sansone M, Marano E, Russo CV, Saccà F, Bonavita V. Dural sinus collapsibility, idiopathic intracranial hypertension, and the pathogenesis of chronic migraine. Neurol Sci 2019; 40:59-70. [PMID: 30838545 DOI: 10.1007/s10072-019-03775-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Available evidences suggest that a number of known assumption on idiopathic intracranial hypertension (IIH) with or without papilledema might be discussed. These include (1) the primary pathogenetic role of an excessive dural sinus collapsibility in IIH, allowing a new relatively stable intracranial fluids pressure balance at higher values; (2) the non-mandatory role of papilledema for a definite diagnosis; (3) the possibly much higher prevalence of IIH without papilledema than currently considered; (4) the crucial role of the cerebral compliance exhaustion that precede the raise in intracranial pressure and that may already be pathologic in cases showing a moderately elevated opening pressure; (5) the role as "intracranial pressure sensor" played by the trigeminovascular innervation of dural sinuses and cortical bridge veins, which could represent a major source of CGRP and may explain the high comorbidity and the emerging causative link between IIHWOP and chronic migraine (CM). Accordingly, the control of intracranial pressure is to be considered a promising new therapeutic target in CM.
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Affiliation(s)
- Roberto De Simone
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Headache Centre, University Federico II of Naples, Via Pansini, 5, 80122, Naples, Italy.
| | - Angelo Ranieri
- Division of Neurology and Stroke Unit, Hospital A. Cardarelli, Naples, Italy
| | - Mattia Sansone
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Headache Centre, University Federico II of Naples, Via Pansini, 5, 80122, Naples, Italy
| | - Enrico Marano
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Headache Centre, University Federico II of Naples, Via Pansini, 5, 80122, Naples, Italy
| | - Cinzia Valeria Russo
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Headache Centre, University Federico II of Naples, Via Pansini, 5, 80122, Naples, Italy
| | - Francesco Saccà
- Department of Neuroscience, Reproductive Sciences and Odontostomatology, Headache Centre, University Federico II of Naples, Via Pansini, 5, 80122, Naples, Italy
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7
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Prada MP, Syed AU, Buonarati OR, Reddy GR, Nystoriak MA, Ghosh D, Simó S, Sato D, Sasse KC, Ward SM, Santana LF, Xiang YK, Hell JW, Nieves-Cintrón M, Navedo MF. A G s-coupled purinergic receptor boosts Ca 2+ influx and vascular contractility during diabetic hyperglycemia. eLife 2019; 8:42214. [PMID: 30821687 PMCID: PMC6397001 DOI: 10.7554/elife.42214] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 02/16/2019] [Indexed: 12/21/2022] Open
Abstract
Elevated glucose increases vascular reactivity by promoting L-type CaV1.2 channel (LTCC) activity by protein kinase A (PKA). Yet, how glucose activates PKA is unknown. We hypothesized that a Gs-coupled P2Y receptor is an upstream activator of PKA mediating LTCC potentiation during diabetic hyperglycemia. Experiments in apyrase-treated cells suggested involvement of a P2Y receptor underlying the glucose effects on LTTCs. Using human tissue, expression for P2Y11, the only Gs-coupled P2Y receptor, was detected in nanometer proximity to CaV1.2 and PKA. FRET-based experiments revealed that the selective P2Y11 agonist NF546 and elevated glucose stimulate cAMP production resulting in enhanced PKA-dependent LTCC activity. These changes were blocked by the selective P2Y11 inhibitor NF340. Comparable results were observed in mouse tissue, suggesting that a P2Y11-like receptor is mediating the glucose response in these cells. These findings established a key role for P2Y11 in regulating PKA-dependent LTCC function and vascular reactivity during diabetic hyperglycemia.
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Affiliation(s)
- Maria Paz Prada
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Arsalan U Syed
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Olivia R Buonarati
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Gopireddy R Reddy
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Matthew A Nystoriak
- Diabetes & Obesity Center, Department of Medicine, University of Louisville, Kentucky, United States
| | - Debapriya Ghosh
- Department of Pharmacology, University of California, Davis, Davis, United States
| | - Sergi Simó
- Department of Cell Biology & Human Anatomy, University of California, Davis, Davis, United States
| | - Daisuke Sato
- Department of Pharmacology, University of California, Davis, Davis, United States
| | | | - Sean M Ward
- Department of Physiology & Cell Biology, University of Nevada, Reno, United States
| | - Luis F Santana
- Department of Physiology & Membrane Biology, University of California, Davis, Davis, United States
| | - Yang K Xiang
- Department of Pharmacology, University of California, Davis, Davis, United States.,VA Northern California Healthcare System, Mather, United States
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, Davis, United States
| | | | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, Davis, United States
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8
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Mahavadi S, Sriwai W, Manion O, Grider JR, Murthy KS. Diabetes-induced oxidative stress mediates upregulation of RhoA/Rho kinase pathway and hypercontractility of gastric smooth muscle. PLoS One 2017; 12:e0178574. [PMID: 28678840 PMCID: PMC5497948 DOI: 10.1371/journal.pone.0178574] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/15/2017] [Indexed: 02/07/2023] Open
Abstract
The pathogenesis of diabetes-associated motility disorders are multifactorial and attributed to abnormalities in extrinsic and intrinsic innervation, and a decrease in the number of interstitial cells of Cajal, and nNOS expression and activity. Here we studied the effect of hyperglycemia on smooth muscle function. Using smooth muscles from the fundus of ob/ob mice and of wild type (WT) mice treated with 30 mM glucose (HG), we identified the molecular mechanism by which hyperglycemia upregulates RhoA/Rho kinase pathway and muscle contraction. RhoA expression, Rho kinase activity and muscle contraction were increased, while miR-133a expression was decreased in smooth muscle of ob/ob mice and in smooth muscle treated with HG. Intraperitoneal injections of pre-miR-133a decreased RhoA expression in WT mice and reversed the increase in RhoA expression in ob/ob mice. Intraperitoneal injections of antagomiR-133a increased RhoA expression in WT mice and augmented the increase in RhoA expression in ob/ob mice. The effect of pre-miR-133a or antagomiR-133a in vitro in smooth muscle treated with HG was similar to that obtained in vivo, suggesting that the expression of RhoA is negatively regulated by miR-133a and a decrease in miR-133a expression in diabetes causes an increase in RhoA expression. Oxidative stress (levels of reactive oxygen species and hydrogen peroxide, and expression of superoxide dismutase 1 and NADPH oxidase 4) was increased in smooth muscle of ob/ob mice and in HG-treated smooth muscle. Treatment of ob/ob mice with N-acetylcysteine (NAC) in vivo or addition of NAC in vitro to HG-treated smooth muscle reversed the effect of glucose on the expression of miR-133a and RhoA, Rho kinase activity and muscle contraction. NAC treatment also reversed the decrease in gastric emptying in ob/ob mice. We conclude that oxidative stress in diabetes causes a decrease in miR-133a expression leading to an increase in RhoA/Rho kinase pathway and muscle contraction.
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Affiliation(s)
- Sunila Mahavadi
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| | - Wimolpak Sriwai
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Olivia Manion
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - John R. Grider
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Karnam S. Murthy
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia, United States of America
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9
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El-Yazbi AF, Abd-Elrahman KS. ROK and Arteriolar Myogenic Tone Generation: Molecular Evidence in Health and Disease. Front Pharmacol 2017; 8:87. [PMID: 28280468 PMCID: PMC5322222 DOI: 10.3389/fphar.2017.00087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/10/2017] [Indexed: 12/13/2022] Open
Abstract
The myogenic response is an inherent property of resistance arteries that warrants a relatively constant blood flow in response to changes in perfusion pressure and protect delicate organs from vascular insufficiencies and excessive blood flow. This fundamental phenomenon has been extensively studied aiming to elucidate the underlying mechanisms triggering smooth muscle contraction in response to intraluminal pressure elevation, particularly, Rho-associated kinase (ROK)-mediated Ca2+-independent mechanisms. The size of the resistance arteries limits the capacity to examine changes in protein phosphorylation/expression levels associated with ROK signaling. A highly sensitive biochemical detection approach was beneficial in examining the role of ROK in different force generation mechanisms along the course of myogenic constriction. In this mini review, we summarize recent results showing direct evidence for the contribution of ROK in development of myogenic response at the level of mechanotransduction, myosin light chain phosphatase inhibition and dynamic actin cytoskeleton reorganization. We will also present evidence that alterations in ROK signaling could underlie the progressive loss in myogenic response in a rat model of type 2 diabetes.
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Affiliation(s)
- Ahmed F El-Yazbi
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of BeirutBeirut, Lebanon; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Khaled S Abd-Elrahman
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of OttawaOttawa, ON, Canada
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10
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Abd-Elrahman KS, Colinas O, Walsh EJ, Zhu HL, Campbell CM, Walsh MP, Cole WC. Abnormal myosin phosphatase targeting subunit 1 phosphorylation and actin polymerization contribute to impaired myogenic regulation of cerebral arterial diameter in the type 2 diabetic Goto-Kakizaki rat. J Cereb Blood Flow Metab 2017; 37:227-240. [PMID: 26721393 PMCID: PMC5363741 DOI: 10.1177/0271678x15622463] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/26/2015] [Accepted: 11/17/2015] [Indexed: 12/11/2022]
Abstract
The myogenic response of cerebral resistance arterial smooth muscle to intraluminal pressure elevation is a key physiological mechanism regulating blood flow to the brain. Rho-associated kinase plays a critical role in the myogenic response by activating Ca2+ sensitization mechanisms: (i) Rho-associated kinase inhibits myosin light chain phosphatase by phosphorylating its targeting subunit myosin phosphatase targeting subunit 1 (at T855), augmenting 20 kDa myosin regulatory light chain (LC20) phosphorylation and force generation; and (ii) Rho-associated kinase stimulates cytoskeletal actin polymerization, enhancing force transmission to the cell membrane. Here, we tested the hypothesis that abnormal Rho-associated kinase-mediated myosin light chain phosphatase regulation underlies the dysfunctional cerebral myogenic response of the Goto-Kakizaki rat model of type 2 diabetes. Basal levels of myogenic tone, LC20, and MYPT1-T855 phosphorylation were elevated and G-actin content was reduced in arteries of pre-diabetic 8-10 weeks Goto-Kakizaki rats with normal serum insulin and glucose levels. Pressure-dependent myogenic constriction, LC20, and myosin phosphatase targeting subunit 1 phosphorylation and actin polymerization were suppressed in both pre-diabetic Goto-Kakizaki and diabetic (18-20 weeks) Goto-Kakizaki rats, whereas RhoA, ROK2, and MYPT1 expression were unaffected. We conclude that abnormal Rho-associated kinase-mediated Ca2+ sensitization contributes to the dysfunctional cerebral myogenic response in the Goto-Kakizaki model of type 2 diabetes.
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Affiliation(s)
- Khaled S Abd-Elrahman
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Olaia Colinas
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Emma J Walsh
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Hai-Lei Zhu
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Christine M Campbell
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Michael P Walsh
- The Smooth Muscle Research Group, Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - William C Cole
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
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Hong K, Zhao G, Hong Z, Sun Z, Yang Y, Clifford PS, Davis MJ, Meininger GA, Hill MA. Mechanical activation of angiotensin II type 1 receptors causes actin remodelling and myogenic responsiveness in skeletal muscle arterioles. J Physiol 2016; 594:7027-7047. [PMID: 27531064 DOI: 10.1113/jp272834] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/09/2016] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Candesartan, an inverse agonist of the type 1 angiotensin II receptor (AT1 R), causes a concentration-dependent inhibition of pressure-dependent myogenic tone consistent with previous reports of mechanosensitivity of this G protein-coupled receptor. Mechanoactivation of the AT1 R occurs independently of local angiotensin II production and the type 2 angiotensin receptor. Mechanoactivation of the AT1 R stimulates actin polymerization by a protein kinase C-dependent mechanism, but independently of a change in intracellular Ca2+ . Using atomic force microscopy, changes in single vascular smooth muscle cell cortical actin are observed to remodel following mechanoactivation of the AT1 R. ABSTRACT The Gq/11 protein-coupled angiotensin II type 1 receptor (AT1 R) has been shown to be activated by mechanical stimuli. In the vascular system, evidence supports the AT1 R being a mechanosensor that contributes to arteriolar myogenic constriction. The aim of this study was to determine if AT1 R mechanoactivation affects myogenic constriction in skeletal muscle arterioles and to determine underlying cellular mechanisms. Using pressure myography to study rat isolated first-order cremaster muscle arterioles the AT1 R inhibitor candesartan (10-7 -10-5 m) showed partial but concentration-dependent inhibition of myogenic reactivity. Inhibition was demonstrated by a rightward shift in the pressure-diameter relationship over the intraluminal pressure range, 30-110 mmHg. Pressure-induced changes in global vascular smooth muscle intracellular Ca2+ (using Fura-2) were similar in the absence or presence of candesartan, indicating that AT1 R-mediated myogenic constriction relies on Ca2+ -independent downstream signalling. The diacylglycerol analogue 1-oleoyl-2-acetyl-sn-glycerol (OAG) reversed the inhibitory effect of candesartan, while this rescue effect was prevented by the protein kinase C (PKC) inhibitor GF 109203X. Both candesartan and PKC inhibition caused increased G-actin levels, as determined by Western blotting of vessel lysates, supporting involvement of cytoskeletal remodelling. At the single vascular smooth muscle cell level, atomic force microscopy showed that cell swelling (stretch) with hypotonic buffer also caused thickening of cortical actin fibres and this was blocked by candesartan. Collectively, the present studies support growing evidence for novel modes of activation of the AT1 R in arterioles and suggest that mechanically activated AT1 R generates diacylglycerol, which in turn activates PKC which induces the actin cytoskeleton reorganization that is required for pressure-induced vasoconstriction.
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Affiliation(s)
- Kwangseok Hong
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65211, USA.,Robert M. Berne Cardiovascular Research Centre and Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, 22908, USA
| | - Guiling Zhao
- College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Zhongkui Hong
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA.,Department of Biomedical Engineering, University of South Dakota, Sioux Falls, SD, 57107, USA
| | - Zhe Sun
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65211, USA
| | - Yan Yang
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA
| | - Philip S Clifford
- College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Michael J Davis
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65211, USA
| | - Gerald A Meininger
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65211, USA
| | - Michael A Hill
- Dalton Cardiovascular Research Centre, University of Missouri, Columbia, MO, 65211, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65211, USA
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Microvascular Dysfunction and Cognitive Impairment. Cell Mol Neurobiol 2016; 36:241-58. [PMID: 26988697 DOI: 10.1007/s10571-015-0308-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/19/2015] [Indexed: 12/18/2022]
Abstract
The impact of vascular risk factors on cognitive function has garnered much interest in recent years. The appropriate distribution of oxygen, glucose, and other nutrients by the cerebral vasculature is critical for proper cognitive performance. The cerebral microvasculature is a key site of vascular resistance and a preferential target for small vessel disease. While deleterious effects of vascular risk factors on microvascular function are known, the contribution of this dysfunction to cognitive deficits is less clear. In this review, we summarize current evidence for microvascular dysfunction in brain. We highlight effects of select vascular risk factors (hypertension, diabetes, and hyperhomocysteinemia) on the pial and parenchymal circulation. Lastly, we discuss potential links between microvascular disease and cognitive function, highlighting current gaps in our understanding.
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El-Yazbi AF, Abd-Elrahman KS, Moreno-Dominguez A. PKC-mediated cerebral vasoconstriction: Role of myosin light chain phosphorylation versus actin cytoskeleton reorganization. Biochem Pharmacol 2015; 95:263-78. [DOI: 10.1016/j.bcp.2015.04.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 04/16/2015] [Indexed: 10/23/2022]
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