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Renden RB, Institoris A, Sharma K, Tran CHT. Modulatory effects of noradrenergic and serotonergic signaling pathway on neurovascular coupling. Commun Biol 2024; 7:287. [PMID: 38459113 PMCID: PMC10923894 DOI: 10.1038/s42003-024-05996-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 02/28/2024] [Indexed: 03/10/2024] Open
Abstract
Dynamic changes in astrocyte Ca2+ are recognized as contributors to functional hyperemia, a critical response to increased neuronal activity mediated by a process known as neurovascular coupling (NVC). Although the critical role of glutamatergic signaling in this process has been extensively investigated, the impact of behavioral state, and the release of behavior-associated neurotransmitters, such as norepinephrine and serotonin, on astrocyte Ca2+ dynamics and functional hyperemia have received less attention. We used two-photon imaging of the barrel cortex in awake mice to examine the role of noradrenergic and serotonergic projections in NVC. We found that both neurotransmitters facilitated sensory stimulation-induced increases in astrocyte Ca2+. Interestingly, while ablation of serotonergic neurons reduced sensory stimulation-induced functional hyperemia, ablation of noradrenergic neurons caused both attenuation and potentiation of functional hyperemia. Our study demonstrates that norepinephrine and serotonin are involved in modulating sensory stimulation-induced astrocyte Ca2+ elevations and identifies their differential effects in regulating functional hyperemia.
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Affiliation(s)
- Robert B Renden
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV, USA
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Kushal Sharma
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV, USA
| | - Cam Ha T Tran
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV, USA.
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2
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Renden RB, Institoris A, Sharma K, Tran CHT. Modulatory Effects of Noradrenergic and Serotonergic Signaling Pathway on Neurovascular Coupling. Res Sq 2023:rs.3.rs-3104893. [PMID: 37502946 PMCID: PMC10371106 DOI: 10.21203/rs.3.rs-3104893/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Dynamic changes in astrocyte Ca2+ are recognized as contributors to functional hyperemia, a critical response to increased neuronal activity mediated by a process known as neurovascular coupling (NVC). Although the critical role of glutamatergic signaling in this process has been extensively investigated, the impact of behavioral state, and the release of behavior-associated neurotransmitters, such as norepinephrine and serotonin, on astrocyte Ca2+ dynamics and functional hyperemia have received less attention. We used two-photon imaging of the barrel cortex in awake mice to examine the role of noradrenergic and serotonergic projections in NVC. We found that both neurotransmitters facilitated sensory-induced increases in astrocyte Ca2+. Interestingly, while ablation of serotonergic neurons reduced sensory-induced functional hyperemia, ablation of noradrenergic neurons caused both attenuation and potentiation of functional hyperemia. Our study demonstrates that norepinephrine and serotonin are involved in modulating sensory-induced astrocyte Ca2+ elevations and identifies their differential effects in regulating functional hyperemia.
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Affiliation(s)
- Robert B Renden
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV, USA
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Kushal Sharma
- Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health and Science University, OR, USA
| | - Cam Ha T. Tran
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV, USA
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3
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Hiess F, Yao J, Song Z, Sun B, Zhang Z, Huang J, Chen L, Institoris A, Estillore JP, Wang R, Ter Keurs HEDJ, Stys PK, Gordon GR, Zamponi GW, Ganguly A, Chen SRW. Subcellular localization of hippocampal ryanodine receptor 2 and its role in neuronal excitability and memory. Commun Biol 2022; 5:183. [PMID: 35233070 PMCID: PMC8888588 DOI: 10.1038/s42003-022-03124-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/01/2022] [Indexed: 11/09/2022] Open
Abstract
Ryanodine receptor 2 (RyR2) is abundantly expressed in the heart and brain. Mutations in RyR2 are associated with both cardiac arrhythmias and intellectual disability. While the mechanisms of RyR2-linked arrhythmias are well characterized, little is known about the mechanism underlying RyR2-associated intellectual disability. Here, we employed a mouse model expressing a green fluorescent protein (GFP)-tagged RyR2 and a specific GFP probe to determine the subcellular localization of RyR2 in hippocampus. GFP-RyR2 was predominantly detected in the soma and dendrites, but not the dendritic spines of CA1 pyramidal neurons or dentate gyrus granular neurons. GFP-RyR2 was also detected within the mossy fibers in the stratum lucidum of CA3, but not in the presynaptic terminals of CA1 neurons. An arrhythmogenic RyR2-R4496C+/− mutation downregulated the A-type K+ current and increased membrane excitability, but had little effect on the afterhyperpolarization current or presynaptic facilitation of CA1 neurons. The RyR2-R4496C+/− mutation also impaired hippocampal long-term potentiation, learning, and memory. These data reveal the precise subcellular distribution of hippocampal RyR2 and its important role in neuronal excitability, learning, and memory. A mouse model containing a GFP-tagged ryanodine receptor 2 (RyR2) has shed light on the precise subcellular localization of hippocampal RyR2 and mechanisms underlying neuronal excitability, learning, and memory.
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Affiliation(s)
- Florian Hiess
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Zhenpeng Song
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Zizhen Zhang
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Junting Huang
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Lina Chen
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Henk E D J Ter Keurs
- Libin Cardiovascular Institute, Department of Cardiovascular Science, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Peter K Stys
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Gerald W Zamponi
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Anutosh Ganguly
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada. .,Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.
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4
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Haidey JN, Peringod G, Institoris A, Gorzo KA, Nicola W, Vandal M, Ito K, Liu S, Fielding C, Visser F, Nguyen MD, Gordon GR. Astrocytes regulate ultra-slow arteriole oscillations via stretch-mediated TRPV4-COX-1 feedback. Cell Rep 2021; 36:109405. [PMID: 34348138 DOI: 10.1016/j.celrep.2021.109405] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/22/2021] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
Very-low-frequency oscillations in microvascular diameter cause fluctuations in oxygen delivery that are important for fueling the brain and for functional imaging. However, little is known about how the brain regulates ongoing oscillations in cerebral blood flow. In mouse and rat cortical brain slice arterioles, we find that selectively enhancing tone is sufficient to recruit a TRPV4-mediated Ca2+ elevation in adjacent astrocyte endfeet. This endfoot Ca2+ signal triggers COX-1-mediated "feedback vasodilators" that limit the extent of evoked vasoconstriction, as well as constrain fictive vasomotion in slices. Astrocyte-Ptgs1 knockdown in vivo increases the power of arteriole oscillations across a broad range of very low frequencies (0.01-0.3 Hz), including ultra-slow vasomotion (∼0.1 Hz). Conversely, clamping astrocyte Ca2+in vivo reduces the power of vasomotion. These data demonstrate bidirectional communication between arterioles and astrocyte endfeet to regulate oscillatory microvasculature activity.
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Affiliation(s)
- Jordan N Haidey
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Govind Peringod
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Kelsea A Gorzo
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Wilten Nicola
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada; Department of Physics and Astronomy, Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Milène Vandal
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Kenichi Ito
- Centre for Genome Engineering, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Shiying Liu
- Centre for Genome Engineering, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Cameron Fielding
- Centre for Genome Engineering, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Frank Visser
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Minh Dang Nguyen
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
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5
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Affiliation(s)
- Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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6
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Yao J, Sun B, Institoris A, Zhan X, Guo W, Song Z, Liu Y, Hiess F, Boyce AKJ, Ni M, Wang R, Ter Keurs H, Back TG, Fill M, Thompson RJ, Turner RW, Gordon GR, Chen SRW. Limiting RyR2 Open Time Prevents Alzheimer's Disease-Related Neuronal Hyperactivity and Memory Loss but Not β-Amyloid Accumulation. Cell Rep 2021; 32:108169. [PMID: 32966798 PMCID: PMC7532726 DOI: 10.1016/j.celrep.2020.108169] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 07/23/2020] [Accepted: 08/27/2020] [Indexed: 12/31/2022] Open
Abstract
Neuronal hyperactivity is an early primary dysfunction in Alzheimer’s disease (AD) in humans and animal models, but effective neuronal hyperactivity-directed anti-AD therapeutic agents are lacking. Here we define a previously unknown mode of ryanodine receptor 2 (RyR2) control of neuronal hyperactivity and AD progression. We show that a single RyR2 point mutation, E4872Q, which reduces RyR2 open time, prevents hyperexcitability, hyperactivity, memory impairment, neuronal cell death, and dendritic spine loss in a severe early-onset AD mouse model (5xFAD). The RyR2-E4872Q mutation upregulates hippocampal CA1-pyramidal cell A-type K+ current, a well-known neuronal excitability control that is downregulated in AD. Pharmacologically limiting RyR2 open time with the R-carvedilol enantiomer (but not racemic carvedilol) prevents and rescues neuronal hyperactivity, memory impairment, and neuron loss even in late stages of AD. These AD-related deficits are prevented even with continued β-amyloid accumulation. Thus, limiting RyR2 open time may be a hyperactivity-directed, non-β-amyloid-targeted anti-AD strategy. Yao et al. show that genetically or pharmacologically limiting the open duration of ryanodine receptor 2 upregulates the A-type potassium current and prevents neuronal hyperexcitability and hyperactivity, memory impairment, neuronal cell death, and dendritic spine loss in a severe early-onset Alzheimer’s disease mouse model, even with continued accumulation of β-amyloid.
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Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; Medical School, Kunming University of Science and Technology, Kunming 650504, China
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Xiaoqin Zhan
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Zhenpeng Song
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Yajing Liu
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Florian Hiess
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Andrew K J Boyce
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Mingke Ni
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Henk Ter Keurs
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Michael Fill
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL 60612, USA
| | - Roger J Thompson
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Ray W Turner
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL 60612, USA.
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7
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Balasubramanian P, Kiss T, Tarantini S, Nyúl-Tóth Á, Ahire C, Yabluchanskiy A, Csipo T, Lipecz A, Tabak A, Institoris A, Csiszar A, Ungvari Z. Obesity-induced cognitive impairment in older adults: a microvascular perspective. Am J Physiol Heart Circ Physiol 2021; 320:H740-H761. [PMID: 33337961 PMCID: PMC8091942 DOI: 10.1152/ajpheart.00736.2020] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Over two-thirds of individuals aged 65 and older are obese or overweight in the United States. Epidemiological data show an association between the degree of adiposity and cognitive dysfunction in the elderly. In this review, the pathophysiological roles of microvascular mechanisms, including impaired endothelial function and neurovascular coupling responses, microvascular rarefaction, and blood-brain barrier disruption in the genesis of cognitive impairment in geriatric obesity are considered. The potential contribution of adipose-derived factors and fundamental cellular and molecular mechanisms of senescence to exacerbated obesity-induced cerebromicrovascular impairment and cognitive decline in aging are discussed.
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Affiliation(s)
- Priya Balasubramanian
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Tamas Kiss
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2International Training Program in Geroscience, Theoretical Medicine Doctoral School, Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Stefano Tarantini
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,3International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, Budapest, Hungary,4Department of Health Promotion Sciences, the Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Ádám Nyúl-Tóth
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,5International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Chetan Ahire
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Andriy Yabluchanskiy
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Tamas Csipo
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,3International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, Budapest, Hungary,6International Training Program in Geroscience, Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Agnes Lipecz
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,3International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Adam Tabak
- 3International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, Budapest, Hungary,7Department of Internal Medicine and Oncology, Faculty of Medicine, Semmelweis University, Budapest, Hungary,8Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Adam Institoris
- 9Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Anna Csiszar
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2International Training Program in Geroscience, Theoretical Medicine Doctoral School, Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- 1Vascular Cognitive Impairment and Neurodegeneration Program, Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging/Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2International Training Program in Geroscience, Theoretical Medicine Doctoral School, Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary,3International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine, Department of Public Health, Semmelweis University, Budapest, Hungary,4Department of Health Promotion Sciences, the Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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8
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Institoris A, Murphy-Royal C, Tarantini S, Yabluchanskiy A, Haidey JN, Csiszar A, Ungvari Z, Gordon GR. Whole brain irradiation in mice causes long-term impairment in astrocytic calcium signaling but preserves astrocyte-astrocyte coupling. GeroScience 2021; 43:197-212. [PMID: 33094399 PMCID: PMC8050172 DOI: 10.1007/s11357-020-00289-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/14/2020] [Indexed: 11/29/2022] Open
Abstract
Whole brain irradiation (WBI) therapy is an important treatment for brain metastases and potential microscopic malignancies. WBI promotes progressive cognitive dysfunction in over half of surviving patients, yet, the underlying mechanisms remain obscure. Astrocytes play critical roles in the regulation of neuronal activity, brain metabolism, and cerebral blood flow, and while neurons are considered radioresistant, astrocytes are sensitive to γ-irradiation. Hallmarks of astrocyte function are the ability to generate stimulus-induced intercellular Ca2+ signals and to move metabolic substrates through the connected astrocyte network. We tested the hypothesis that WBI-induced cognitive impairment associates with persistent impairment of astrocytic Ca2+ signaling and/or gap junctional coupling. Mice were subjected to a clinically relevant protocol of fractionated WBI, and 12 to 15 months after irradiation, we confirmed persistent cognitive impairment compared to controls. To test the integrity of astrocyte-to-astrocyte gap junctional coupling postWBI, astrocytes were loaded with Alexa-488-hydrazide by patch-based dye infusion, and the increase of fluorescence signal in neighboring astrocyte cell bodies was assessed with 2-photon microscopy in acute slices of the sensory-motor cortex. We found that WBI did not affect astrocyte-to-astrocyte gap junctional coupling. Astrocytic Ca2+ responses induced by bath administration of phenylephrine (detected with Rhod-2/AM) were also unaltered by WBI. However, an electrical stimulation protocol used in long-term potentiation (theta burst), revealed attenuated astrocyte Ca2+ responses in the astrocyte arbor and soma in WBI. Our data show that WBI causes a long-lasting decrement in synaptic-evoked astrocyte Ca2+ signals 12-15 months postirradiation, which may be an important contributor to cognitive decline seen after WBI.
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Affiliation(s)
- Adam Institoris
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Ciaran Murphy-Royal
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Stefano Tarantini
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Andriy Yabluchanskiy
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jordan N Haidey
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Anna Csiszar
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Zoltan Ungvari
- Department of Biochemistry and Molecular Biology, Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Grant R Gordon
- Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
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9
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Vandal M, Gunn C, Bourassa P, Institoris A, Shin SS, Jiang Y, Tremblay C, Belzil C, Bennett DA, Gordon G, Calon F, Nguyen MD. Defining the role of the Alzheimer disease risk factor CD2AP in brain vascular function. Alzheimers Dement 2020. [DOI: 10.1002/alz.040566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Milene Vandal
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | - Colin Gunn
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | | | - Adam Institoris
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | - Steven Seungjae Shin
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | - Yulan Jiang
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | | | - Camille Belzil
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | - David A. Bennett
- Rush Alzheimer's Disease Center Rush University Medical Center Chicago IL USA
| | - Grant Gordon
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
| | - Frederic Calon
- CHU de Quebec Quebec QC Canada
- Université Laval Quebec QC Canada
| | - Minh Dang Nguyen
- University of Calgary Calgary AB Canada
- Hotchkiss Brain Institute Calgary AB Canada
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10
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Institoris A, Lenti L, Domoki F, Wappler E, Gáspár T, Katakam PV, Bari F, Busija DW. Cerebral microcirculatory responses of insulin-resistant rats are preserved to physiological and pharmacological stimuli. Microcirculation 2013; 19:749-56. [PMID: 22845548 DOI: 10.1111/j.1549-8719.2012.00213.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 07/23/2012] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Previously, we have shown that IR impairs the vascular reactivity of the major cerebral arteries of ZO rats prior to the occurrence of Type-II diabetes mellitus. However, the functional state of the microcirculation in the cerebral cortex is still being explored. METHODS We tested the local CoBF responses of 11-13-week-old ZO (n = 31) and control ZL (n = 32) rats to several stimuli measured by LDF using a closed cranial window setup. RESULTS The topical application of 1-100 μm bradykinin elicited the same degree of CoBF elevation in both ZL and ZO groups. There was no significant difference in the incidence, latency, and amplitude of the NMDA-induced CSD-related hyperemia between the ZO and ZL groups. Hypercapnic CoBF response to 5% carbon-dioxide ventilation did not significantly change in the ZO compared with the ZL. Topical bicuculline-induced cortical seizure was accompanied by the same increase of CoBF in both the ZO and ZL at all bicuculline doses. CONCLUSIONS CoBF responses of the microcirculation are preserved in the early period of the metabolic syndrome, which creates an opportunity for intervention to prevent and restore the function of the major cerebral vascular beds.
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Affiliation(s)
- Adam Institoris
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.
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11
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Wappler EA, Institoris A, Dutta S, Katakam PVG, Busija DW. Mitochondrial dynamics associated with oxygen-glucose deprivation in rat primary neuronal cultures. PLoS One 2013; 8:e63206. [PMID: 23658809 PMCID: PMC3642144 DOI: 10.1371/journal.pone.0063206] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 04/02/2013] [Indexed: 12/29/2022] Open
Abstract
Our objective was to investigate the mitochondrial dynamics following oxygen-glucose deprivation (OGD) in cultured rat cortical neurons. We documented changes in morphology, protein expression, and DNA levels in mitochondria following OGD and examined the roles of mitochondrial fission [dynamin-related protein 1 (Drp1), fission protein-1 (Fis1)] and fusion [mitofusin-1 (Mfn1), mitofusin-2 (Mfn2), and optic atrophy-1 protein (OPA1)] proteins on mitochondrial biogenesis and morphogenesis. We tested the effects of two Drp1 blockers [15-deoxy-Δ12,14-Prostaglandin J2 (PGJ2) and Mitochondrial Division Inhibitor (Mdivi-1)] on mitochondrial dynamics and cell survival. One hour of OGD had minimal effects on neuronal viability but mitochondria appeared condensed. Three hours of OGD caused a 60% decrease in neuronal viability accompanied by a transition from primarily normal/tubular and lesser number of rounded mitochondria during normoxia to either poorly labeled or small and large rounded mitochondria. The percentage of rounded mitochondria remained the same. The mitochondrial voltage-dependent anion channel, Complex V, and mitoDNA levels increased after OGD associated with a dramatic reduction in Drp1 expression, less reduction in Mfn2 expression, an increase in Mfn1 expression, with no changes in either OPA1 or Fis1. Although PGJ2 increased polymerization of Drp1, it did not reduce cell death or alter mitochondrial morphology following OGD and Mdivi-1 did not protect neurons against OGD. In summary, mitochondrial biogenesis and maintained fusion occurred in neurons along with mitochondrial fission following OGD; thus Mfn1 but not Drp1 may be a major regulator of these processes.
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Affiliation(s)
- Edina A Wappler
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America.
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12
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Katakam PVG, Wappler EA, Katz PS, Rutkai I, Institoris A, Domoki F, Gáspár T, Grovenburg SM, Snipes JA, Busija DW. Depolarization of mitochondria in endothelial cells promotes cerebral artery vasodilation by activation of nitric oxide synthase. Arterioscler Thromb Vasc Biol 2013; 33:752-9. [PMID: 23329133 DOI: 10.1161/atvbaha.112.300560] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Mitochondrial depolarization after ATP-sensitive potassium channel activation has been shown to induce cerebral vasodilation by the generation of calcium sparks in smooth muscle. It is unclear, however, whether mitochondrial depolarization in endothelial cells is capable of promoting vasodilation by releasing vasoactive factors. Therefore, we studied the effect of endothelial mitochondrial depolarization by mitochondrial ATP-sensitive potassium channel activators, BMS-191095 (BMS) and diazoxide, on endothelium-dependent vasodilation. APPROACH AND RESULTS Diameter studies in isolated rat cerebral arteries showed BMS- and diazoxide-induced vasodilations that were diminished by endothelial denudation. Mitochondrial depolarization-induced vasodilation was reduced by inhibition of mitochondrial ATP-sensitive potassium channels, phosphoinositide-3 kinase, or nitric oxide synthase. Scavenging of reactive oxygen species, however, diminished vasodilation induced by diazoxide, but not by BMS. Fluorescence studies in cultured rat brain microvascular endothelial cells showed that BMS elicited mitochondrial depolarization and enhanced nitric oxide production; diazoxide exhibited largely similar effects, but unlike BMS, increased mitochondrial reactive oxygen species production. Measurements of intracellular calcium ([Ca(2+)]i) in cultured rat brain microvascular endothelial cells and arteries showed that both diazoxide and BMS increased endothelial [Ca(2+)]i. Western blot analyses revealed increased phosphorylation of protein kinase B and endothelial nitric oxide synthase (eNOS) by BMS and diazoxide. Increased phosphorylation of eNOS by diazoxide was abolished by phosphoinositide-3 kinase inhibition. Electron spin resonance spectroscopy confirmed vascular nitric oxide generation in response to diazoxide and BMS. CONCLUSIONS Pharmacological depolarization of endothelial mitochondria promotes activation of eNOS by dual pathways involving increased [Ca(2+)]i as well as by phosphoinositide-3 kinase-protein kinase B-induced eNOS phosphorylation. Both mitochondrial reactive oxygen species-dependent and -independent mechanisms mediate activation of eNOS by endothelial mitochondrial depolarization.
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Affiliation(s)
- Prasad V G Katakam
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
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13
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Clark D, Tuor UI, Thompson R, Institoris A, Kulynych A, Zhang X, Kinniburgh DW, Bari F, Busija DW, Barber PA. Protection against recurrent stroke with resveratrol: endothelial protection. PLoS One 2012; 7:e47792. [PMID: 23082218 PMCID: PMC3474795 DOI: 10.1371/journal.pone.0047792] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 09/17/2012] [Indexed: 11/18/2022] Open
Abstract
Despite increased risk of a recurrent stroke following a minor stroke, information is minimal regarding the interaction between injurious mild cerebral ischemic episodes and the possible treatments which might be effective. The aim of the current study was to investigate recurrent ischemic stroke and whether resveratrol, a nutritive polyphenol with promising cardio- and neuro- protective properties, could ameliorate the associated brain damage. Experiments in adult rats demonstrated that a mild ischemic stroke followed by a second mild cerebral ischemia exacerbated brain damage, and, daily oral resveratrol treatment after the first ischemic insult reduced ischemic cell death with the recurrent insult (P<0.002). Further investigation demonstrated reduction of both inflammatory changes and markers of oxidative stress in resveratrol treated animals. The protection observed with resveratrol treatment could not be explained by systemic effects of resveratrol treatment including effects either on blood pressure or body temperature measured telemetrically. Investigation of resveratrol effects on the blood-brain barrier in vivo demonstrated that resveratrol treatment reduced blood-brain barrier disruption and edema following recurrent stroke without affecting regional cerebral blood flow. Investigation of the mechanism in primary cell culture studies demonstrated that resveratrol treatment significantly protected endothelial cells against an in vitro ‘ischemia’ resulting in improved viability against oxygen and glucose deprivation (39.6±6.6% and 81.3±9.5% in vehicle and resveratrol treated cells, respectively). An inhibition of nitric oxide synthesis did not prevent the improved cell viability following oxygen glucose deprivation but SIRT-1 inhibition with sirtinol partially blocked the protection (P<0.001) suggesting endothelial protection is to some extent SIRT-1 dependent. Collectively, the results support that oral resveratrol treatment provides a low risk strategy to protect the brain from enhanced damage produced by recurrent stroke which is mediated in part by a protective effect of resveratrol on the endothelium of the cerebrovasculature.
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Affiliation(s)
- Darren Clark
- Departments of Physiology and Pharmacology, Clinical Neurosciences and Radiology, University of Calgary, Calgary, Canada
- Hotchkiss Brain Institute and Faculty of Medicine, University of Calgary, Calgary, Canada
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Ursula I. Tuor
- Departments of Physiology and Pharmacology, Clinical Neurosciences and Radiology, University of Calgary, Calgary, Canada
- Hotchkiss Brain Institute and Faculty of Medicine, University of Calgary, Calgary, Canada
- * E-mail:
| | - Roger Thompson
- Hotchkiss Brain Institute and Faculty of Medicine, University of Calgary, Calgary, Canada
| | - Adam Institoris
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Angela Kulynych
- Hotchkiss Brain Institute and Faculty of Medicine, University of Calgary, Calgary, Canada
| | - Xu Zhang
- Alberta Centre for Toxicology, University of Calgary, Calgary, Canada
| | | | - Ferenc Bari
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - David W. Busija
- Department of Pharmacology, Tulane University, New Orleans, Louisiana, United States of America
| | - Philip A. Barber
- Hotchkiss Brain Institute and Faculty of Medicine, University of Calgary, Calgary, Canada
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14
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Wappler EA, Institoris A, Katakam PV, Busija DW. Abstract 3903: Dynamin-related Protein 1 Independent Apoptosis In Neurons Following Oxygen-glucose Deprivation. Stroke 2012. [DOI: 10.1161/str.43.suppl_1.a3903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and purpose:
Previous studies showed that mitochondrial (mito) fission occurs prior to apoptosis and that a key initiator is the mito fission protein dynamin-related protein 1 (Drp1). However, little information is available concerning mito dynamics in neurons due to OGD. Therefore, we investigated mito fission and mito fusion responses in cultured neurons in an
in vitro
model of brain ischemia.
Methods:
Primary rat cortical neurons were isolated from E18 Sprague Dawley fetuses. Neurons were exposed to OGD 9 days after culturing for 3 hr followed by up to 24 hr of reoxygenation. Mito dynamics were investigated by measuring the expression of: 1) mito fission [Drp1; mito fission 1 (Fis1)] and mito fusion [mitofusin-2 (Mfn2); optic atrophy-1 (OPA1)] proteins; 2) electron transport chain proteins (complex II 70 kDa subunit, complex IV subunit I, complex V alpha subunit); 3) mito DNA; and 4) apoptosis protein Bax. We also examined neuronal and mito morphology using transmission electron microscopy. The effects of the Drp1 inhibitors 15d-Prostaglandin J
2
(2.5-20 µM) (15d-PGJ
2
) and Mdivi-1 (2.5-250 µM) were also investigated.
Results:
3hr OGD followed by 3-24 hr recovery resulted in an increase in the level of mito DNA and enhanced expression of complex IV and V proteins. During this time, abnormal morphology, including enlarged and/or swollen mitochondria, was often observed. However, many mitochondria still retained normal morphology. Drp1 levels decreased before virtually disappearing by 6 hr of reoxygenation following OGD while Fis1 expression did not change. Bax expression increased with an increasing number of apoptotic cells during this time. Mfn2 decreased after OGD while OPA1 did not change significantly. 15d-PGJ
2
treatment dose-dependently increased cell death both in control and OGD-exposed neurons. Furthermore, 15d-PGJ
2
treatment surprisingly increased Drp1 both in controls and in OGD-exposed cells, and also increased the mito DNA. Additionally, 15d-PGJ
2
treatment itself increased the number of larger mitochondria in the neurons. However, Mdivi-1 did not have any effects.
Conclusions:
Despite a lower fission/fusion protein ratio, the increase in mitochondrial size indicates a shift to enhanced fusion in neurons following OGD. In addition, apoptosis induction seems to be Drp1 independent in this model. Additionally, 15d-PGJ
2
treatment appears to decrease survival in neurons following OGD. Thus, mito dynamics are affected by OGD and 15d-PGJ
2
treatment and play a role in cell survival/death.
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Affiliation(s)
| | - Adam Institoris
- Dept of Physiology, Sch of Medicine, Univ of Szeged, Szeged, Hungary
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15
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Institoris A, Snipes JA, Katakam PV, Domoki F, Boda K, Bari F, Busija DW. Impaired vascular responses of insulin-resistant rats after mild subarachnoid hemorrhage. Am J Physiol Heart Circ Physiol 2011; 300:H2080-7. [PMID: 21421821 DOI: 10.1152/ajpheart.01169.2010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin resistance (IR) impairs cerebrovascular responses to several stimuli in Zucker obese (ZO) rats. However, cerebral artery responses after subarachnoid hemorrhage (SAH) have not been described in IR. We hypothesized that IR worsens vascular reactions after a mild SAH. Hemolyzed blood (300 μl) or saline was infused (10 μl/min) into the cisterna magna of 11-13-wk-old ZO (n = 25) and Zucker lean (ZL) rats (n = 25). One day later, dilator responses of the basilar artery (BA) and its side branch (BA-Br) to acetylcholine (ACh, 10(-6) M), cromakalim (10(-7) M, 10(-6) M), and sodium nitroprusside (10(-7) M) were recorded with intravital videomicroscopy. The baseline diameter of the BA was increased both in the ZO and ZL rats 24 h after the hemolysate injection. Saline-injected ZO animals showed reduced dilation to ACh (BA = 9 ± 3 vs. 22 ± 4%; and BA-Br = 23 ± 5 vs. 37 ± 7%) compared with ZL rats. Hemolysate injection blunted the response to ACh in both the ZO (BA = 4 ± 2%; and BA-Br = 12 ± 3%) and ZL (BA = 7 ± 2%; and BA-Br = 11 ± 3%) rats. Cromakalim (10(-6) M)-induced dilation was significantly reduced in the hemolysate-injected ZO animals compared with the saline control (BA = 13 ± 3 vs. 26 ± 5%; and BA-Br = 28 ± 8 vs. 44 ± 9%) and in the hemolysate-injected ZL rats compared with their saline control (BA = 24 ± 4 vs. 32 ± 4%; but not BA-Br = 39 ± 6 vs. 59 ± 9%). No significant difference in sodium nitroprusside reactivity was observed. Western blot analysis of the BA showed a lower baseline level of neuronal nitric oxide synthase expression and an enhanced cyclooxygenase-2 level in the hemolysate-injected ZO animals. In summary, cerebrovascular reactivity to both endothelium-dependent and -independent stimuli is severely compromised by SAH in IR animals.
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Affiliation(s)
- Adam Institoris
- Dept. of Pharmacology, Tulane Univ., 1430 Tulane Ave., SL 83, New Orleans, LA, 70112-2632, USA
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16
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Institoris A, Gaspar T, Katakam PV, Domoki F, Bari F, Busija DW. Pre‐ and postconditioning with the mitochondrial ATP‐sensitive potassium (mitoKATP) channel opener BMS‐191095 protects cerebral endothelial cells against oxygen glucose deprivation (OGD). FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.598.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Adam Institoris
- Department of Physiology and PharmacologyWake Forest University Health SciencesWinston‐SalemNC
| | - Tamas Gaspar
- Department of Physiology and PharmacologyWake Forest University Health SciencesWinston‐SalemNC
| | - Prasad V. Katakam
- Department of Physiology and PharmacologyWake Forest University Health SciencesWinston‐SalemNC
| | | | - Ferenc Bari
- Department of Medical InformaticsUniversity of SzegedSzegedHungary
| | - David W. Busija
- Department of Physiology and PharmacologyWake Forest University Health SciencesWinston‐SalemNC
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17
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Katakam PV, Institoris A, Ferenc D, Gaspar T, Snipes JA, Busija DW. Microvascular endothelial mitochondria and nitric oxide generation. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.777.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Prasad V.G Katakam
- Physiology and PharmacologyWake Forest University Health SciencesWinston SalemNC
| | - Adam Institoris
- Physiology and PharmacologyWake Forest University Health SciencesWinston SalemNC
| | - Domoki Ferenc
- Physiology and PharmacologyWake Forest University Health SciencesWinston SalemNC
| | - Tamas Gaspar
- Physiology and PharmacologyWake Forest University Health SciencesWinston SalemNC
| | - James A Snipes
- Physiology and PharmacologyWake Forest University Health SciencesWinston SalemNC
| | - David W Busija
- Physiology and PharmacologyWake Forest University Health SciencesWinston SalemNC
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18
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Institoris A, Domoki F, Bari F, Busija DW. Cerebrovascular reactivity after experimental subarachnoid hemorrhage (SAH) in insulin resistant (IR) rats. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.978.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Adam Institoris
- Department of Physiology and PharmacologyWake Forest University Health SciencesWinston‐SalemNC
- Department of Physiology
| | | | - Ferenc Bari
- Department of Medical InformaticsUniversity of SzegedSzegedHungary
| | - David W. Busija
- Department of Physiology and PharmacologyWake Forest University Health SciencesWinston‐SaelmNC
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19
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Abstract
Effects of insulin on cerebral arteries have never been examined. Therefore, we determined cerebrovascular actions of insulin in rats. Both PCR and immunoblot studies identified insulin receptor expression in cerebral arteries and in cultured cerebral microvascular endothelial cells (CMVECs). Diameter measurements (% change) of isolated rat cerebral arteries showed a biphasic dose response to insulin with an initial vasoconstriction at 0.1 ng/mL (-9.7%+/-1.6%), followed by vasodilation at 1 to 100 ng/mL (31.9%+/-1.4%). Insulin also increased cortical blood flow in vivo (30%+/-8% at 120 ng/mL) when applied topically. Removal of reactive oxygen species (ROS) abolished the vasoconstriction to insulin. Endothelial denudation, inhibition of K(+) channels, and nitric oxide (NO) synthase, all diminished insulin-induced vasodilation. Inhibition of cytochrome P450 enhanced vasodilation in endothelium-intact arteries, but promoted vasoconstriction after endothelial denudation. Inhibition of cyclooxygenase abolished vasoconstriction and enhanced vasodilation to insulin in all arteries. Inhibition of endothelin type A receptors enhanced vasodilation, whereas endothelin type B receptor blockade diminished vasodilation. Insulin treatment in vitro increased Akt phosphorylation in cerebral arteries and CMVECs. Fluorescence studies of CMVECs showed that insulin increased intracellular calcium and enhanced the generation of NO and ROS. Thus, cerebrovascular responses to insulin were mediated by complex mechanisms originating in both the endothelium and smooth muscle.
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20
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Institoris A, Farkas E, Berczi S, Sule Z, Bari F. Effects of cyclooxygenase (COX) inhibition on memory impairment and hippocampal damage in the early period of cerebral hypoperfusion in rats. Eur J Pharmacol 2007; 574:29-38. [PMID: 17719573 DOI: 10.1016/j.ejphar.2007.07.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 07/02/2007] [Accepted: 07/04/2007] [Indexed: 11/23/2022]
Abstract
Chronic cerebral hypoperfusion is related to neurological disorders and contributes to a cognitive decline. Its experimental model in rats is permanent, bilateral common carotid artery occlusion. The cyclooxygenase (COX) system plays a pivotal role in the evolution of ischemic brain damage. Several COX inhibitors have proved to be neuroprotective in stroke models. We set out to characterize the effects of COX inhibitors in rats with permanent cerebral hypoperfusion. Some of the animals were exposed to two-vessel occlusion (n=72), while the others served as sham-operated controls (n=54). This was followed by a 3-day post-treatment with the nonselective COX inhibitor indomethacin (3 mg/kg) or with the selective COX-2 inhibitor NS-398 (15 mg/kg) or with the solvent. Some groups of the animals were sacrificed after 3 days, while the remainder were tested in the Morris watermaze for 5 days, and were sacrificed after 2 weeks. Neurons in the hippocampus were subjected to immunocytochemical labeling with cresyl violet, the dendrites with microtubule-associated protein-2, astrocytes with glial fibrillary acidic protein and microglia activation with OX-42 antibody. Two-vessel occlusion induced a learning impairment, mild neuronal damage, marked dendritic injury and moderate astrocytic reaction in the hippocampus. NS-398, but not indomethacin improved the survival rate and abolished the learning disability. However, both drugs increased the proportion of animals displaying neuronal damage. Glial markers revealed a time-dependent elevation in both the sham and the two-vessel occluded group, and were unaffected by the treatments. In summary, NS-398 prevented the hypoperfusion-induced memory impairment, but not by protecting the hippocampal neurons.
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Affiliation(s)
- Adam Institoris
- Department of Physiology, School of Medicine, University of Szeged, H-6720 Szeged, Dóm tér 10, Hungary.
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21
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Farkas E, Domoki F, Institoris A, Annahazi A, W. Busija D, Bari F. Neuroprotection by Diazoxide in Animal Models for Cerebrovascular Disorders. ACTA ACUST UNITED AC 2006. [DOI: 10.2174/156727006778019167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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