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Gao J, Guo Z, Zhao M, Cheng X, Jiang X, Liu Y, Zhang W, Yue X, Fei X, Jiang Y, Chen L, Zhang S, Zhao T, Zhu L. Lipidomics and mass spectrometry imaging unveil alterations in mice hippocampus lipid composition exposed to hypoxia. J Lipid Res 2024; 65:100575. [PMID: 38866327 PMCID: PMC11333011 DOI: 10.1016/j.jlr.2024.100575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/14/2024] Open
Abstract
Lipids are components of cytomembranes that are involved in various biochemical processes. High-altitude hypoxic environments not only affect the body's energy metabolism, but these environments can also cause abnormal lipid metabolism involved in the hypoxia-induced cognitive impairment. Thus, comprehensive lipidomic profiling of the brain tissue is an essential step toward understanding the mechanism of cognitive impairment induced by hypoxic exposure. In the present study, mice showed reduced new-object recognition and spatial memory when exposed to hypobaric hypoxia for 1 day. Histomorphological staining revealed significant morphological and structural damage to the hippocampal tissue, along with prolonged exposure to hypobaric hypoxia. Dynamic lipidomics of the mouse hippocampus showed a significant shift in both the type and distribution of phospholipids, as verified by spatial lipid mapping. Collectively, a diverse and dynamic lipid composition in mice hippocampus was uncovered, which deepens our understanding of biochemical changes during sustained hypoxic exposure and could provide new insights into the cognitive decline induced by high-altitude hypoxia exposure.
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Affiliation(s)
- Jiayue Gao
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Zhiying Guo
- Hepato-pancreato-biliary Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Ming Zhao
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xiang Cheng
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xiufang Jiang
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Yikun Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Wenpeng Zhang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Xiangpei Yue
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xuechao Fei
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Yaqun Jiang
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Lu Chen
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Shaojie Zhang
- Department of Gastroenterology, The Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Tong Zhao
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Lingling Zhu
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.
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Frias-Anaya E, Gallego-Gutierrez H, Gongol B, Weinsheimer S, Lai CC, Orecchioni M, Sriram A, Bui CM, Nelsen B, Hale P, Pham A, Shenkar R, DeBiasse D, Lightle R, Girard R, Li Y, Srinath A, Daneman R, Nudleman E, Sun H, Guma M, Dubrac A, Mesarwi OA, Ley K, Kim H, Awad IA, Ginsberg MH, Lopez-Ramirez MA. Mild Hypoxia Accelerates Cerebral Cavernous Malformation Disease Through CX3CR1-CX3CL1 Signaling. Arterioscler Thromb Vasc Biol 2024; 44:1246-1264. [PMID: 38660801 PMCID: PMC11111348 DOI: 10.1161/atvbaha.123.320367] [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: 11/01/2023] [Accepted: 04/05/2024] [Indexed: 04/26/2024]
Abstract
BACKGROUND Heterogeneity in the severity of cerebral cavernous malformations (CCMs) disease, including brain bleedings and thrombosis that cause neurological disabilities in patients, suggests that environmental, genetic, or biological factors act as disease modifiers. Still, the underlying mechanisms are not entirely understood. Here, we report that mild hypoxia accelerates CCM disease by promoting angiogenesis, neuroinflammation, and vascular thrombosis in the brains of CCM mouse models. METHODS We used genetic studies, RNA sequencing, spatial transcriptome, micro-computed tomography, fluorescence-activated cell sorting, multiplex immunofluorescence, coculture studies, and imaging techniques to reveal that sustained mild hypoxia via the CX3CR1-CX3CL1 (CX3C motif chemokine receptor 1/chemokine [CX3C motif] ligand 1) signaling pathway influences cell-specific neuroinflammatory interactions, contributing to heterogeneity in CCM severity. RESULTS Histological and expression profiles of CCM neurovascular lesions (Slco1c1-iCreERT2;Pdcd10fl/fl; Pdcd10BECKO) in male and female mice found that sustained mild hypoxia (12% O2, 7 days) accelerates CCM disease. Our findings indicate that a small reduction in oxygen levels can significantly increase angiogenesis, neuroinflammation, and thrombosis in CCM disease by enhancing the interactions between endothelium, astrocytes, and immune cells. Our study indicates that the interactions between CX3CR1 and CX3CL1 are crucial in the maturation of CCM lesions and propensity to CCM immunothrombosis. In particular, this pathway regulates the recruitment and activation of microglia and other immune cells in CCM lesions, which leads to lesion growth and thrombosis. We found that human CX3CR1 variants are linked to lower lesion burden in familial CCMs, proving it is a genetic modifier in human disease and a potential marker for aggressiveness. Moreover, monoclonal blocking antibody against CX3CL1 or reducing 1 copy of the Cx3cr1 gene significantly reduces hypoxia-induced CCM immunothrombosis. CONCLUSIONS Our study reveals that interactions between CX3CR1 and CX3CL1 can modify CCM neuropathology when lesions are accelerated by environmental hypoxia. Moreover, a hypoxic environment or hypoxia signaling caused by CCM disease influences the balance between neuroinflammation and neuroprotection mediated by CX3CR1-CX3CL1 signaling. These results establish CX3CR1 as a genetic marker for patient stratification and a potential predictor of CCM aggressiveness.
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MESH Headings
- Animals
- Female
- Humans
- Male
- Mice
- Chemokine CX3CL1/metabolism
- Chemokine CX3CL1/genetics
- CX3C Chemokine Receptor 1/genetics
- CX3C Chemokine Receptor 1/metabolism
- Disease Models, Animal
- Hemangioma, Cavernous, Central Nervous System/genetics
- Hemangioma, Cavernous, Central Nervous System/metabolism
- Hemangioma, Cavernous, Central Nervous System/pathology
- Hypoxia/metabolism
- Hypoxia/complications
- Mice, Inbred C57BL
- Mice, Knockout
- Neovascularization, Pathologic/metabolism
- Neuroinflammatory Diseases/metabolism
- Neuroinflammatory Diseases/pathology
- Neuroinflammatory Diseases/genetics
- Signal Transduction
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Affiliation(s)
- Eduardo Frias-Anaya
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Helios Gallego-Gutierrez
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Brendan Gongol
- Department of Health Sciences, Victor Valley College, Victorville, CA (B.G.)
- Institute for Integrative Genome Biology, 1207F Genomics Building, University of California, Riverside (B.G.)
| | - Shantel Weinsheimer
- Department of Anesthesia and Perioperative Care, Institute for Human Genetics, University of California, San Francisco (S.W., A.S., H.K.)
| | - Catherine Chinhchu Lai
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Marco Orecchioni
- Division of Inflammation Biology, La Jolla Institute for Immunology, CA (M.O., K.L.)
| | - Aditya Sriram
- Department of Anesthesia and Perioperative Care, Institute for Human Genetics, University of California, San Francisco (S.W., A.S., H.K.)
| | - Cassandra M Bui
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Bliss Nelsen
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Preston Hale
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Angela Pham
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Robert Shenkar
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Dorothy DeBiasse
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Rhonda Lightle
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Romuald Girard
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Ying Li
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Abhinav Srinath
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Richard Daneman
- Department of Pharmacology (R.D., M.A.L.-R.), University of California San Diego, La Jolla
| | - Eric Nudleman
- Department of Ophthalmology (E.N.), University of California San Diego, La Jolla
| | - Hao Sun
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Monica Guma
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Alexandre Dubrac
- Centre de Recherche, CHU St. Justine, Montréal, Quebec, Canada. Département de Pathologie et Biologie Cellulaire, Université de Montréal, Quebec, Canada (A.D.)
| | - Omar A Mesarwi
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Immunology, CA (M.O., K.L.)
| | - Helen Kim
- Department of Anesthesia and Perioperative Care, Institute for Human Genetics, University of California, San Francisco (S.W., A.S., H.K.)
| | - Issam A Awad
- Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago Medicine and Biological Sciences, IL (R.S., D.D., R.L., R.G., Y.L., A.S., I.A.A.)
| | - Mark H Ginsberg
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
| | - Miguel Alejandro Lopez-Ramirez
- Department of Medicine (E.F.-A., H.G.-G., C.C.L., C.M.B., B.N., P.H., A.P., H.S., M.G., O.A.M., M.H.G., M.A.L.-R.), University of California San Diego, La Jolla
- Department of Pharmacology (R.D., M.A.L.-R.), University of California San Diego, La Jolla
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Zhong Y, Liu F, Zhang X, Guo Q, Wang Z, Wang R. Research progress on reproductive system damage caused by high altitude hypoxia. Endocrine 2024; 83:559-570. [PMID: 38170433 DOI: 10.1007/s12020-023-03643-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024]
Abstract
PURPOSE The high altitude area is characterized by low pressure and hypoxia, and rapidly entering the high altitude area will cause a series of damage to the body. Some studies have shown that hypoxia can cause damage to the reproductive system. In recent years, researchers have been paying attention to the effects of hypoxia on hormone level, ovarian reserve, embryonic development, testicular development, sperm motility level, and have begun to explore its injury mechanism, but its mechanism is not clear. In this paper, the mechanism of hypoxia on the reproductive system is reviewed, which is expected to provide a new idea for solving the problem of the low fertility rate of humans and animals at high altitudes. METHODS A comprehensive PubMed search was conducted, selecting all relevant peer-reviewed English papers published before January 2022. Other relevant papers were selected from the list of references. RESULTS Studies have shown that the complete fertility rate of people living at low altitudes is 7.7, and the complete fertility rate of people living at high altitudes is 4.77, and the hypoxic environment at high altitudes reduces fertility. At the same time, high-altitude, low-oxygen environments are associated with increased infant mortality and post-neonatal mortality. To date, most studies seem to point to a correlation between anoxic exposure at high altitudes and low fertility in humans and animals. CONCLUSION Although the molecular mechanisms are not fully understood, the effects of hypoxia at high altitude on hormonal level, ovarian reserve, embryonic development, testicular development, and sperm motility and levels require further research to investigate this complex topic.
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Affiliation(s)
- Yan Zhong
- School of Pharmacy, Gansu University of Traditional Chinese Medicine, Lanzhou, China.
- Pharmacy of the 940th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army, Lanzhou, China.
| | - Feifei Liu
- School of Pharmacy, Gansu University of Traditional Chinese Medicine, Lanzhou, China
- Pharmacy of the 940th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army, Lanzhou, China
| | - Xiaojing Zhang
- Pharmacy of the 940th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army, Lanzhou, China.
| | - Qianwen Guo
- Pharmacy of the 940th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army, Lanzhou, China
| | - Zihan Wang
- Pharmacy of the 940th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army, Lanzhou, China
| | - Rong Wang
- Pharmacy of the 940th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army, Lanzhou, China.
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4
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Jeong H, Pan Y, Akhter F, Volkow ND, Zhu D, Du C. Impairment of cerebral vascular reactivity and resting blood flow in early-staged transgenic AD mice: in vivo optical imaging studies. RESEARCH SQUARE 2023:rs.3.rs-3579916. [PMID: 37987006 PMCID: PMC10659553 DOI: 10.21203/rs.3.rs-3579916/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Background Alzheimer's disease (AD) is a neurodegenerative disorder with progressive cognitive decline in aging individuals that poses a significant challenge to patients due to an incomplete understanding of its etiology and lack of effective interventions. While "the Amyloid Cascade Hypothesis," the abnormal accumulation of amyloid-β in the brain, has been the most prevalent theory for AD, mounting evidence from clinical and epidemiological studies suggest that defects in cerebral vessels and hypoperfusion appear prior to other pathological manifestations and might contribute to AD, leading to "the Vascular Hypothesis." However, assessment of structural and functional integrity of the cerebral vasculature in vivo in the brain from AD rodent models has been challenging owing to the limited spatiotemporal resolution of conventional imaging technologies. Methods We employed two in vivo imaging technologies, i.e., Dual-Wavelength Imaging (DWI) and Optical Coherence Tomography (OCT), to evaluate cerebrovascular reactivity (CVR; responsiveness of blood vessels to vasoconstriction as triggered by cocaine) in a relatively large field of view of the cortex in vivo, and 3D quantitative cerebrovascular blood flow (CBF) imaging in living transgenic AD mice at single vessel resolution. Results Our results showed significantly impaired CVR and reduced CBF in basal state in transgenic AD mice compared to non-transgenic littermates in an early stage of AD progression. Changes in total hemoglobin (Δ[HbT]) in response to vasoconstriction were significantly attenuated in AD mice, especially in arteries and tissue, and the recovery time of Δ[HbT] after vasoconstriction was shorter for AD than WT in all types of vessels and cortical tissue, thereby indicating hypoperfusion and reduced vascular flexibility. Additionally, our 3D OCT images revealed that CBF velocities in arteries were slower and that the microvascular network was severely disrupted in the brain of AD mice. Conclusions These results suggest significant vascular impairment in basal CBF and dynamic CVR in the neurovascular network in a rodent model of AD at an early stage of the disease. These cutting-edge in vivo optical imaging tools offer an innovative venue for detecting early neurovascular dysfunction in relation to AD pathology and pave the way for clinical translation of early diagnosis and elucidation of AD pathogenesis in the future.
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Affiliation(s)
- Hyomin Jeong
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Firoz Akhter
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20857, USA
| | - Donghui Zhu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
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5
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Dias C, Fernandes E, Barbosa RM, Laranjinha J, Ledo A. Astrocytic aerobic glycolysis provides lactate to support neuronal oxidative metabolism in the hippocampus. Biofactors 2023; 49:875-886. [PMID: 37070143 DOI: 10.1002/biof.1951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/23/2023] [Indexed: 04/19/2023]
Abstract
Under physiological conditions, the energetic demand of the brain is met by glucose oxidation. However, ample evidence suggests that lactate produced by astrocytes through aerobic glycolysis may also be an oxidative fuel, highlighting the metabolic compartmentalization between neural cells. Herein, we investigate the roles of glucose and lactate in oxidative metabolism in hippocampal slices, a model that preserves neuron-glia interactions. To this purpose, we used high-resolution respirometry to measure oxygen consumption (O2 flux) at the whole tissue level and amperometric lactate microbiosensors to evaluate the concentration dynamics of extracellular lactate. We found that lactate is produced from glucose and transported to the extracellular space by neural cells in hippocampal tissue. Under resting conditions, endogenous lactate was used by neurons to support oxidative metabolism, which was boosted by exogenously added lactate even in the presence of excess glucose. Depolarization of hippocampal tissue with high K+ significantly increased the rate of oxidative phosphorylation, which was accompanied by a transient decrease in extracellular lactate concentration. Both effects were reverted by inhibition of the neuronal lactate transporter, monocarboxylate transporters 2 (MCT2), supporting the concept of an inward flux of lactate to neurons to fuel oxidative metabolism. We conclude that astrocytes are the main source of extracellular lactate which is used by neurons to fuel oxidative metabolism, both under resting and stimulated conditions.
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Affiliation(s)
- Cândida Dias
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Eliana Fernandes
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Rui M Barbosa
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - João Laranjinha
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Ana Ledo
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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Sapkota A, Halder SK, Milner R. Hypoxia-induced vascular remodeling responses in the brain are much more robust than other organs. Microvasc Res 2023; 148:104517. [PMID: 36894025 PMCID: PMC10258146 DOI: 10.1016/j.mvr.2023.104517] [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: 12/28/2022] [Revised: 02/16/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023]
Abstract
Exposure to chronic mild hypoxia (CMH; 8-10% O2) promotes a robust vascular remodeling response in the brain resulting in 50% increased vessel density over a period of two weeks. It is currently unknown whether blood vessels in other organs show similar responses. To address this question, mice were exposed to CMH for 4 days and various markers of vascular remodeling were examined in the brain along with heart, skeletal muscle, kidney, and liver. In contrast to brain, where CMH strongly promoted endothelial proliferation, none of the peripheral organs showed this response and in heart and liver, CMH notably reduced endothelial proliferation. While the MECA-32 endothelial activation marker was strongly induced by CMH in brain, in peripheral organs it was constitutively expressed either on a sub-population of vessels (heart and skeletal muscle) or on all vessels (kidney and liver), and notably, CMH did not affect expression. Endothelial expression of the tight junction proteins claudin-5 and ZO-1 were markedly increased on cerebral vessels, but in the peripheral organs examined, CMH either had no effect or reduced ZO-1 expression (liver). Finally, while CMH had no impact on the number of Mac-1 positive macrophages in the brain, heart, or skeletal muscle, this number was markedly decreased in the kidney but increased in the liver. Our findings show that the vascular remodeling responses to CMH are organ-specific, with the brain showing a strong angiogenic response and enhanced tight junction protein expression, but heart, skeletal muscle, kidney, and liver failing to show these responses.
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Affiliation(s)
- Arjun Sapkota
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA 92121, USA
| | - Sebok K Halder
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 3525 John Hopkins Court, Suite 200, San Diego, CA 92121, USA.
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The Effects of Intranasal Implantation of Mesenchymal Stem Cells on Nitric Monoxide Levels in the Hippocampus, Control of Cognitive Functions, and Motor Activity in a Model of Cerebral Ischemia in Rats. BIONANOSCIENCE 2023. [DOI: 10.1007/s12668-023-01072-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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8
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Acute Hypobaric Hypoxia Exposure Causes Neurobehavioral Impairments in Rats: Role of Brain Catecholamines and Tetrahydrobiopterin Alterations. Neurochem Res 2023; 48:471-486. [PMID: 36205808 DOI: 10.1007/s11064-022-03767-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/12/2022] [Accepted: 09/22/2022] [Indexed: 02/07/2023]
Abstract
Hypoxia is a state in which the body or a specific part of the body is deprived of adequate oxygen supply at the tissue level. Sojourners involved in different activities at high altitudes (> 2500 m) face hypobaric hypoxia (HH) due to low oxygen in the atmosphere. HH is an example of generalized hypoxia, where the homeostasis of the entire body of an organism is affected and results in neurochemical changes. It is known that lower O2 levels affect catecholamines (CA), severely impairing cognitive and locomotor behavior. However, there is less evidence on the effect of HH-mediated alteration in brain Tetrahydrobiopterin (BH4) levels and its role in neurobehavioral impairments. Hence, this study aimed to shed light on the effect of acute HH on CA and BH4 levels with its neurobehavioral impact on Wistar rat models. After HH exposure, significant alteration of the CA levels in the discrete brain regions, viz., frontal cortex, hippocampus, midbrain, and cerebellum was observed. HH exposure significantly reduced spontaneous motor activity, motor coordination, and spatial memory. The present study suggests that the HH-induced behavioral changes might be related to the alteration of the expression pattern of CA and BH4-related genes and proteins in different rat brain regions. Overall, this study provides novel insights into the role of BH4 and CA in HH-induced neurobehavioral impairments.
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9
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Zhang X, Xie W, Liu Y, Li M, Lin J, Yin W, Yang L, Li P, Sun Y, Li T, Liu H, Ma H, Zhang J. Brain Structural and Functional Alterations in Native Tibetans Living at High Altitude. Neuroscience 2023; 520:134-143. [PMID: 36716913 DOI: 10.1016/j.neuroscience.2023.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 01/15/2023] [Accepted: 01/18/2023] [Indexed: 01/30/2023]
Abstract
Tibetans have adapted to high altitude environments. However, the genetic effects in their brains have not been identified. Twenty-five native Tibetans living in Lhasa (3650 m) were recruited for comparison with 20 Han immigrants who originated from lowlands and had been living in Lhasa for two years. The physiological characteristics, brain structure and neuronal spontaneous activity were investigated. Compared with Han immigrants, Tibetans showed higher peripheral oxygen saturation (SpO2), and lower heart rate, red blood cell counts, hematocrit, and hemoglobin. Tibetans showed increased gray matter volume in the visual cortex, hippocampus, and rectus; increased the amplitudes of low-frequency fluctuations (ALFF) values in the left putamen and left fusiform gyrus; and decreased voxel-mirrored homotopic connectivity (VMHC) values in the precentral gyrus. Moreover, Tibetans have decreased functional connectivity (FC) between the left precentral gyrus and the frontal gyrusand right precuneus. In Tibetans and Han immigrants, hemoglobin and hematocrit were negatively correlated with total gray matter volume in males, SpO2 was also positively correlated with ALFF in the left fusiform gyrus, while hemoglobin, and hematocrit were positively correlated with VMHC in the precentral gyrus and FC in the precentral gyrus with other brain regions, SpO2 was also found to be negatively correlated with VMHC in the precentral gyrus, and hemoglobin and hematocrit were negatively correlated with ALFF in the left putamen and left fusiform gyrus. In summary, genetic mutations may result in modulation of some brain regions, which was further confirmed by the identification of correlations with hemoglobin and hematocrit in these regions.
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Affiliation(s)
- Xinjuan Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Weiwei Xie
- Plateau Brain Science Research Centre, Tibet University, Lhasa 850012, China
| | - Yanqiu Liu
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Minglu Li
- Department of Clinical Medicine, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Jianzhong Lin
- Department of Radiology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Wu Yin
- Department of Radiology, Tibet Autonomous Region People's Hospital, Lhasa 850000, Tibet Autonomous Region, China
| | - Lihui Yang
- Department of Endocrinology, Tibet Autonomous Region People's Hospital, Lhasa 850000, Tibet Autonomous Region, China
| | - Pengji Li
- Plateau Brain Science Research Centre, Tibet University, Lhasa 850012, China
| | - Ying Sun
- Plateau Brain Science Research Centre, Tibet University, Lhasa 850012, China
| | - Tianzhi Li
- Plateau Brain Science Research Centre, Tibet University, Lhasa 850012, China
| | - Haipeng Liu
- Department of Radiology, Tibet Autonomous Region Women's and Children's Hospital, Lhasa 850000, Tibet Autonomous Region, China
| | - Hailin Ma
- Plateau Brain Science Research Centre, Tibet University, Lhasa 850012, China.
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China.
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10
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Orekhova K, Selmanovic E, De Gasperi R, Gama Sosa MA, Wicinski B, Maloney B, Seifert A, Alipour A, Balchandani P, Gerussi T, Graïc JM, Centelleghe C, Di Guardo G, Mazzariol S, Hof PR. Multimodal Assessment of Bottlenose Dolphin Auditory Nuclei Using 7-Tesla MRI, Immunohistochemistry and Stereology. Vet Sci 2022; 9:vetsci9120692. [PMID: 36548853 PMCID: PMC9781543 DOI: 10.3390/vetsci9120692] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/05/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
The importance of assessing neurochemical processes in the cetacean brain as a tool for monitoring their cognitive health and to indirectly model human neurodegenerative conditions is increasingly evident, although available data are largely semiquantitative. High-resolution MRI for post-mortem brains and stereology allow for quantitative assessments of the cetacean brain. In this study, we scanned two brains of bottlenose dolphins in a 7-Tesla (7T) MR scanner and assessed the connectivity of the inferior colliculi and ventral cochlear nuclei using diffusion tensor imaging (DTI). Serial thick sections were investigated stereologically in one of the dolphins to generate rigorous quantitative estimates of identifiable cell types according to their morphology and expression of molecular markers, yielding reliable cell counts with most coefficients of error <10%. Fibronectin immunoreactivity in the dolphin resembled the pattern in a human chronic traumatic encephalopathy brain, suggesting that neurochemical compensation for insults such as hypoxia may constitute a noxious response in humans, while being physiological in dolphins. These data contribute to a growing body of knowledge on the morphological and neurochemical properties of the dolphin brain and highlight a stereological and neuroimaging workflow that may enable quantitative and translational assessment of pathological processes in the dolphin brain in the future.
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Affiliation(s)
- Ksenia Orekhova
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
- Correspondence:
| | - Enna Selmanovic
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rita De Gasperi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, NY 10468, USA
| | - Miguel A. Gama Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- General Medical Research Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, New York, NY 10468, USA
| | - Bridget Wicinski
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Brigid Maloney
- Laboratory of Neurogenetics of Vocal Learning, Rockefeller University, New York, NY 10065, USA
| | - Alan Seifert
- Department of Radiology, BioMedical Engineering and Imaging Institute (BMEII), Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Akbar Alipour
- Department of Radiology, BioMedical Engineering and Imaging Institute (BMEII), Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Priti Balchandani
- Department of Radiology, BioMedical Engineering and Imaging Institute (BMEII), Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tommaso Gerussi
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Cinzia Centelleghe
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Giovanni Di Guardo
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy
| | - Sandro Mazzariol
- Department of Comparative Biomedicine and Food Science, University of Padova AGRIPOLIS, Viale dell’Università 16, 35020 Legnaro, Italy
| | - Patrick R. Hof
- Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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11
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Halder SK, Milner R. Exaggerated hypoxic vascular breakdown in aged brain due to reduced microglial vasculo-protection. Aging Cell 2022; 21:e13720. [PMID: 36130175 PMCID: PMC9649604 DOI: 10.1111/acel.13720] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/04/2022] [Accepted: 08/31/2022] [Indexed: 01/25/2023] Open
Abstract
In a recent study of young mice, we showed that chronic mild hypoxia (CMH, 8% O2 ) triggers transient blood-brain barrier (BBB) disruption, and that microglia play an important vasculo-protective function in maintaining BBB integrity. As hypoxia is a common component of many age-related diseases, here we extended these studies to aged mice and found that hypoxia-induced vascular leak was greatly amplified (5-fold to 10-fold) in aged mice, being particularly high in the olfactory bulb and midbrain. While aged mice showed no obvious difference in the early stages of hypoxic angiogenic remodeling, the compensatory increase in vascularity and vessel maturation was significantly delayed. Compared with young brain, microglia in the normoxic aged brain were markedly activated, and this was further increased under hypoxic conditions, but paradoxically, this correlated with reduced vasculo-protection. Microglial depletion studies showed that microglial still play an important vasculo-protective role in aged brain, but interestingly, partial attenuation of microglial activation with minocycline resulted in fewer vascular leaks and reduced loss of endothelial tight junction proteins. Taken together, these findings suggest that increased BBB disruption in hypoxic aged mice can be explained both by a delayed vascular remodeling response and reduced microglial vasculo-protection. Importantly, they show that overly activated microglia in the aged brain are less effective at maintaining vascular integrity, though this can be improved by reducing microglial activation with minocycline, suggesting therapeutic potential for enhancing BBB integrity in the hypoxia-predisposed elderly population.
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Affiliation(s)
- Sebok K. Halder
- San Diego Biomedical Research InstituteSan DiegoCaliforniaUSA
| | - Richard Milner
- San Diego Biomedical Research InstituteSan DiegoCaliforniaUSA
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12
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Morphogenesis of vascular and neuronal networks and the relationships between their remodeling processes. Brain Res Bull 2022; 186:62-69. [DOI: 10.1016/j.brainresbull.2022.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/18/2022] [Accepted: 05/29/2022] [Indexed: 11/21/2022]
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13
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DA Q, Zhang J, Zhang P, Shi Z, Ma H, Jing L. Design, synthesis and anti-hypoxia activity of HPN derivatives containing lipophilic long chains. Zhejiang Da Xue Xue Bao Yi Xue Ban 2022; 51:415-421. [PMID: 37202092 DOI: 10.3724/zdxbyxb-2022-0174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
OBJECTIVE To design and synthesize long-chain substituted 2-[(4'-hydroxyethoxy) phenyl]-4,4,5,5-tetramethyl-2-imidazoline-1-oxyl 3-oxide (HPN) derivatives with enhanced anti-hypoxic activity. METHODS HPN derivatives 1, 3, 5 containing lipophilic long chains were synthesized via the alkylation of HPN with 6-bromohexan-1-ol, ethyl 6-bromohexanoate or 6-bromohexane, respectively using acetonitrile as the solvent and K 2CO 3 as the acid-binding agent at 60 ℃. Derivative 2 was synthesized via hydrolysis reactions of derivative 1 in the NaOH/CH 3OH/H 2O system. Using dichloromethane as the solvent and N, N'-diisopropylcarbodiimide as the dehydrating agent, HPN underwent esterification with hexanoic acid to obtain derivative 4. The structures of derivatives 1-5 were characterized by infrared spectroscopy, electron paramagnetic resonance and high resolution mass spectrometry. The purities of derivatives were detected by high performance liquid chromatography, and the lipid solubilities of derivatives were evaluated by calculating the oil-water partition coefficients (log P). Anti-hypoxia activities of HPN and its long-chain lipophilic derivatives 1-5 were evaluated using normobaric hypoxia test and acute decompression hypoxia test. RESULTS The structures of the derivatives were confirmed by infrared spectroscopy, electron paramagnetic resonance and high resolution mass spectroscopy. The yields of target derivatives were all above 92%, and the purities were all above 96%. The log P values of derivatives 1-5 were 2.78, 2.00, 2.04, 2.88 and 3.10, which were higher than that of HPN (0.97). Derivatives 1-5 significantly prolonged the survival time of mice at the dose of 0.3 mmol/kg in normobaric hypoxic test and reduced the mortality rate of acute decompression hypoxic mice to 60%, 70%, 60%, 70% and 40%, respectively. CONCLUSIONS The synthesis of derivatives 1-5 is convenient, and the yield is high. The synthesized derivatives especially derivative 5 show anti-hypoxic activity similar to or better than HPN at lower doses.
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Affiliation(s)
- Qingyue DA
- 1. School of Pharmacy, Lanzhou University, Lanzhou 730000, China
- 2. Center for Brain Science, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Jie Zhang
- 3. Department of pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Pengpeng Zhang
- 3. Department of pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Zhiqun Shi
- 3. Department of pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Huiping Ma
- 3. Department of pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Linlin Jing
- 2. Center for Brain Science, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
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14
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Isasi E, Figares M, Abudara V, Olivera-Bravo S. Gestational and Lactational Iron Deficiency Anemia Impairs Myelination and the Neurovascular Unit in Infant Rats. Mol Neurobiol 2022; 59:3738-3754. [PMID: 35381889 DOI: 10.1007/s12035-022-02798-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 03/09/2022] [Indexed: 11/25/2022]
Abstract
Iron deficiency anemia is a prevalent health problem among pregnant women and infants, particularly in the developing countries that causes brain development deficits and poor cognitive outcomes. Since tissue iron depletion may impair myelination and trigger cellular hypoxic signaling affecting blood vessels, we studied myelination and the neurovascular unit (NVU) in infant rats born to mothers fed with an iron deficient (ID) or control diet from embryonic day 5 till weaning. Blood samples and brains of rat pups at postnatal day (PND) 14 and 30 were analyzed. PND 14 ID rats had severe microcytic hypochromic anemia that was almost reversed at PND 30 although hypomyelination and astrocyte immature phenotype in the corpus callosum were significant at that age. In CA1 hippocampal region, PND 14 and PND 30 ID rats showed significant reduced expression of the receptor β of the platelet-derived growth factor localized in pericytes and associated to aquaporin 4 (AQP4) immunopositive capillaries. Shorter AQP4 + capillaries and reduced AQP4 expression were also evidenced in PND 14 and PND 30 ID rats. In addition, pericyte membrane permeability through large-pore channels was transiently increased in ID rats at PND 14 but not at PND 30, while the blood-brain barrier permeability was not affected. Remarkably, transient increased pericyte permeability found in PND 14 ID rats was not directly related to iron depletion, suggesting the involvement of other iron deficiency anemia-induced mechanisms. In summary, severe ID during gestation and lactation produces persistent hypomyelination and significantly affects hippocampal pericytes and astrocytes in the NVU which may trigger impaired neurovascular function.
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Affiliation(s)
- Eugenia Isasi
- Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), 3318, Italia Av., 11600, Montevideo, Uruguay
- Neurobiología Celular y Molecular, Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Martin Figares
- Neurobiología Celular y Molecular, Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Silvia Olivera-Bravo
- Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), 3318, Italia Av., 11600, Montevideo, Uruguay.
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15
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Suemori T, Nagano T, Sunoki K, Shinohara T, Taga N, Takeuchi M. Clinical significance of assessing cerebral blood volume by time-domain near-infrared spectroscopy in children with congenital heart disease. Paediatr Anaesth 2022; 32:413-420. [PMID: 34797589 DOI: 10.1111/pan.14338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Despite providing cerebral tissue oxygen saturation (StO2 ), the lack of quantitative information for continuous wave near-infrared spectroscopy (CW-NIRS) is an obstacle in evaluating cerebral hemodynamic conditions. Time-domain NIRS (TD-NIRS) provides both StO2 and cerebral blood volume and has recently become clinically available. AIM To investigate if the additional monitoring of cerebral blood volume by TD-NIRS facilitates the understanding of cerebral hemodynamic conditions in patients with congenital heart disease. METHODS Preoperative TD-NIRS values were retrospectively reviewed in patients who underwent a cardiac surgery or catheter examination. We compared the values between patients with single and two ventricles. Moreover, we investigated the association of these values with the demographic and clinical variables. RESULTS There was no significant difference in StO2 between single ventricle and two ventricles groups (median: 59.9 vs. 54.4, median difference [95% CI]: -4.06 [-9.90 to 2.90], p = .37). However, cerebral blood volume was significantly higher in the single ventricle group (median: 4.68 vs. 2.84, median difference [95% CI]: -2.01 [-2.88 to -1.06], p < .001). Spearman's rank correlation analysis demonstrated an association between StO2 and postmenstrual age (r = 0.35, p = .03). In contrast, cerebral blood volume was correlated with single ventricle physiology (r = 0.62, p < .001), postmenstrual age (r = 0.74, p < .001), central venous pressure (r = 0.38, p = .02), and SaO2 (r = -0.38, p = .02). The multivariable regression analysis identified the postmenstrual age, single ventricle physiology, and SaO2 as independent factors associated with cerebral blood volume. In the logistic analysis, cerebral blood volume was identified as a significant predictor of unfavorable conditions. CONCLUSION Cerebral blood volume monitoring detected differences in cerebral hemodynamic conditions, related to the age and the type of ventricle physiologies. However, the differences were not apparent in StO2 . The additional monitoring of cerebral blood volume by TD-NIRS would facilitate a better understanding of cerebral hemodynamic conditions in patients with congenital heart disease.
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Affiliation(s)
- Tomohiko Suemori
- Department of Pediatric Intensive Care and Anesthesia, Jichi Children's Medical Center Tochigi, Tochigi, Japan
| | - Tatsuya Nagano
- Department of Pediatric Intensive Care and Anesthesia, Jichi Children's Medical Center Tochigi, Tochigi, Japan
| | - Kohei Sunoki
- Department of Pediatric Intensive Care and Anesthesia, Jichi Children's Medical Center Tochigi, Tochigi, Japan
| | - Takako Shinohara
- Department of Pediatric Intensive Care and Anesthesia, Jichi Children's Medical Center Tochigi, Tochigi, Japan
| | - Naoyuki Taga
- Department of Pediatric Intensive Care and Anesthesia, Jichi Children's Medical Center Tochigi, Tochigi, Japan
| | - Mamoru Takeuchi
- Department of Pediatric Intensive Care and Anesthesia, Jichi Children's Medical Center Tochigi, Tochigi, Japan
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16
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Komarovsky MB, Tsipis CP, Almotah KA, Boron WF, Xu K, LaManna J. Postnatal Exposure to Brief Hypoxia Alters Brain VEGF Expression and Capillary Density in Adult Mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1395:65-68. [PMID: 36527615 DOI: 10.1007/978-3-031-14190-4_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Perinatal hypoxia leads to changes in cerebral angiogenesis and persistent structural and functional changes in the adult brain. It may also result in greater vulnerability to subsequent challenges. We investigated the effect of postnatal day 2 (P2) hypoxic preconditioning on adult brain capillary density and brain vascular endothelial growth factor (VEGF) expression in mice. P2 mice were exposed to hypoxia (5% O2) in a normobaric chamber for 2 h then returned to normoxia while their littermates remained in normoxia (P2 control). After 2-6 months, they were euthanised and their brains were removed for capillary density determination. Another set of animals (P2 hypoxic mice and P2 controls) were euthanised at 2, 10, 23, and 60 days after birth and brain VEGF expression was assessed by western blot. Adult brain capillary density was significantly increased in the P2 hypoxic mice when compared to the P2 control mice. Additionally, VEGF expression appeared to be elevated in the P2-hypoxia mice when compared to the P2-control mice at all time points, and VEGF levels in P2-hypoxia mice declined with age similarly to P2-control mice. These data demonstrate that transient early-postnatal hypoxic stress leads to an increase in capillary density that persists in the adult, possibly due to increased VEGF expression. These results might be explained by epigenetic factors in the VEGF gene.
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17
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Xu K, Ji H, Hu N. Cardiovascular comorbidities in amyotrophic lateral sclerosis: A systematic review. J Clin Neurosci 2021; 96:43-49. [PMID: 34974247 DOI: 10.1016/j.jocn.2021.12.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/10/2021] [Accepted: 12/20/2021] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To summarize the prevalence of the cardiovascular comorbidities in patients with amyotrophic lateral sclerosis (ALS) and explore the impacts of cardiovascular diseases on ALS. METHODS PubMed, EMBASE, OVID and Web of Science were searched systematically until July 2021 for studies on the prevalence of cardiovascular diseases among ALS patients or quantitatively investigating the effects of cardiovascular comorbidities on incidence, progression or survival of ALS. We conducted a fixed-effects or random-effects meta-analysis to calculate the summary rate or ORs (odds ratios) with 95 %CIs (confidence intervals). RESULTS The comorbidity of hypertension in France (56.9%) was the highest, followed by Portugal (48%). Only 15% of Chinese ALS patients suffered from hypertension. A quarter of ALS patients in America had coronary heart disease while only 4-5% of patients with ALS in Australia or the Netherlands suffered from coronary heart disease. There was significant relationship between hypertension and survival of ALS (OR: 1.04, 95%CI: 1.01, 1.07). Coronary heart disease was considerably related to ALS onset (OR: 1.19, 95%CI: 1.14, 1.24) and heart failure could noticeably accelerate the progression rate of ALS (OR: 6.33, 95%CI: 1.55, 24.84). CONCLUSIONS Cardiovascular comorbidities in ALS patients varied significantly with different regions. Hypertension could reduce the survival of ALS so the intensive treatment of chronic hypertension should be recommended to ALS patients in clinical practice. Coronary heart disease could increase the risk of ALS and heart failure was a negative prognostic factor for ALS, which deserved more attention of clinicians.
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Affiliation(s)
- Ke Xu
- Department of Cardiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China
| | - Hongyan Ji
- Department of Hematopathology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China
| | - Nan Hu
- Department of Neurology, Peking Union Medical College Hospital, Beijing, 100730, China.
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18
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Halder SK, Milner R. The impact of chronic mild hypoxia on cerebrovascular remodelling; uncoupling of angiogenesis and vascular breakdown. Fluids Barriers CNS 2021; 18:50. [PMID: 34789271 PMCID: PMC8597176 DOI: 10.1186/s12987-021-00284-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chronic mild hypoxia (CMH, 8% O2) stimulates robust vascular remodelling in the brain, but it also triggers transient vascular disruption. This raises the fundamental question: is the vascular leak an unwanted side-effect of angiogenic remodelling or is it a pathological response, unrelated to endothelial proliferation, in which declining oxygen levels trigger endothelial dysfunction? METHODS To answer this question, mice were exposed to CMH (8% O2) for periods up to 14 days, after which, brain tissue was examined by immunofluorescence (IF) to determine which type of blood vessel (arteriole, capillary or venule) was most commonly associated with endothelial proliferation and vascular leak and how this correlated with tight junction protein expression. Vascular perfusion was examined using DiI. Data were analysed using one-way analysis of variance (ANOVA) followed by Tukey's multiple comparison post-hoc test. RESULTS The following was observed: (1) most endothelial proliferation and extravascular fibrinogen leak occurred in capillaries and to a lesser degree in venules, (2) much to our surprise, endothelial proliferation and extravascular fibrinogen leak never colocalized, (3) interestingly however, endothelial proliferation was strongly associated with an intravascular fibrinogen staining pattern not seen in stable blood vessels, (4) DiI perfusion studies revealed that angiogenic vessels were adequately perfused, suggesting that fibrinogen retention in angiogenic vessels is not due to temporary closure of the vessel, but more likely because fibrinogen is retained within the vessel wall, (5) bromodeoxyuridine (BrdU) labelling as a means to more permanently label proliferating endothelial cells, confirmed lack of any connection between endothelial proliferation and extravascular fibrinogen leak, while (6) in contrast, proliferating microglia were detected within extravascular leaks. CONCLUSIONS Taken together, our findings support the concept that in the short-term, hypoxia-induced endothelial proliferation triggers transient fibrinogen deposition within the walls of angiogenic blood vessels, but no overt vascular leak occurs in these vessels. Importantly, endothelial proliferation and extravascular fibrinogen leaks never co-localize, demonstrating that extravascular leak is not an unwanted side-effect of angiogenic endothelial proliferation, but rather a dysfunctional vascular response to hypoxia that occurs in a distinct group of non-angiogenic blood vessels.
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Affiliation(s)
- Sebok K Halder
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA, 92121, USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA, 92121, USA.
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19
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Burtscher J, Mallet RT, Burtscher M, Millet GP. Hypoxia and brain aging: Neurodegeneration or neuroprotection? Ageing Res Rev 2021; 68:101343. [PMID: 33862277 DOI: 10.1016/j.arr.2021.101343] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/12/2022]
Abstract
The absolute reliance of the mammalian brain on oxygen to generate ATP renders it acutely vulnerable to hypoxia, whether at high altitude or in clinical settings of anemia or pulmonary disease. Hypoxia is pivotal to the pathogeneses of myriad neurological disorders, including Alzheimer's, Parkinson's and other age-related neurodegenerative diseases. Conversely, reduced environmental oxygen, e.g. sojourns or residing at high altitudes, may impart favorable effects on aging and mortality. Moreover, controlled hypoxia exposure may represent a treatment strategy for age-related neurological disorders. This review discusses evidence of hypoxia's beneficial vs. detrimental impacts on the aging brain and the molecular mechanisms that mediate these divergent effects. It draws upon an extensive literature search on the effects of hypoxia/altitude on brain aging, and detailed analysis of all identified studies directly comparing brain responses to hypoxia in young vs. aged humans or rodents. Special attention is directed toward the risks vs. benefits of hypoxia exposure to the elderly, and potential therapeutic applications of hypoxia for neurodegenerative diseases. Finally, important questions for future research are discussed.
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Affiliation(s)
- Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland; Institute of Sport Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland.
| | - Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland
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20
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Mallet RT, Burtscher J, Richalet JP, Millet GP, Burtscher M. Impact of High Altitude on Cardiovascular Health: Current Perspectives. Vasc Health Risk Manag 2021; 17:317-335. [PMID: 34135590 PMCID: PMC8197622 DOI: 10.2147/vhrm.s294121] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Globally, about 400 million people reside at terrestrial altitudes above 1500 m, and more than 100 million lowlanders visit mountainous areas above 2500 m annually. The interactions between the low barometric pressure and partial pressure of O2, climate, individual genetic, lifestyle and socio-economic factors, as well as adaptation and acclimatization processes at high elevations are extremely complex. It is challenging to decipher the effects of these myriad factors on the cardiovascular health in high altitude residents, and even more so in those ascending to high altitudes with or without preexisting diseases. This review aims to interpret epidemiological observations in high-altitude populations; present and discuss cardiovascular responses to acute and subacute high-altitude exposure in general and more specifically in people with preexisting cardiovascular diseases; the relations between cardiovascular pathologies and neurodegenerative diseases at altitude; the effects of high-altitude exercise; and the putative cardioprotective mechanisms of hypobaric hypoxia.
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Affiliation(s)
- Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Jean-Paul Richalet
- Laboratoire Hypoxie & Poumon, UMR Inserm U1272, Université Sorbonne Paris Nord 13, Bobigny Cedex, F-93017, France
| | - Gregoire P Millet
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, A-6020, Austria
- Austrian Society for Alpine and High-Altitude Medicine, Mieming, Austria
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21
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Snyder BD, Simone SM, Giovannetti T, Floyd TF. Cerebral Hypoxia: Its Role in Age-Related Chronic and Acute Cognitive Dysfunction. Anesth Analg 2021; 132:1502-1513. [PMID: 33780389 PMCID: PMC8154662 DOI: 10.1213/ane.0000000000005525] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Postoperative cognitive dysfunction (POCD) has been reported with widely varying frequency but appears to be strongly associated with aging. Outside of the surgical arena, chronic and acute cerebral hypoxia may exist as a result of respiratory, cardiovascular, or anemic conditions. Hypoxia has been extensively implicated in cognitive impairment. Furthermore, disease states associated with hypoxia both accompany and progress with aging. Perioperative cerebral hypoxia is likely underdiagnosed, and its contribution to POCD is underappreciated. Herein, we discuss the various disease processes and forms in which hypoxia may contribute to POCD. Furthermore, we outline hypoxia-related mechanisms, such as hypoxia-inducible factor activation, cerebral ischemia, cerebrovascular reserve, excitotoxicity, and neuroinflammation, which may contribute to cognitive impairment and how these mechanisms interact with aging. Finally, we discuss opportunities to prevent and manage POCD related to hypoxia.
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Affiliation(s)
- Brina D. Snyder
- Department of Anesthesiology and Pain Management, UT Southwestern Medical Center, Dallas, TX
| | | | | | - Thomas F. Floyd
- Department of Anesthesiology and Pain Management, UT Southwestern Medical Center, Dallas, TX
- Department of Cardiothoracic Surgery, UT Southwestern Medical Center, Dallas, TX
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22
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Faber JE, Storz JF, Cheviron ZA, Zhang H. High-altitude rodents have abundant collaterals that protect against tissue injury after cerebral, coronary and peripheral artery occlusion. J Cereb Blood Flow Metab 2021; 41:731-744. [PMID: 32703056 PMCID: PMC7983333 DOI: 10.1177/0271678x20942609] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/03/2020] [Accepted: 06/22/2020] [Indexed: 12/22/2022]
Abstract
Collateral number/density varies widely in brain and other tissues among strains of Mus musculus mice due to differences in genetic background. Recent studies have shown that prolonged exposure to reduced atmospheric oxygen induces additional collaterals to form, suggesting that natural selection may favor increased collaterals in populations native to high-altitude. High-altitude guinea pigs (Cavia) and deer mice (Peromyscus) were compared with lowland species of Peromyscus, Mus and Rattus (9 species/strains examined). Collateral density, diameter and other morphometrics were measured in brain where, importantly, collateral abundance reflects that in other tissues of the same individual. Guinea pigs and high-altitude deer mice had a greater density of pial collaterals than lowlanders. Consistent with this, guinea pigs and highlander mice evidenced complete and 80% protection against stroke, respectively. They also sustained significantly less ischemia in heart and lower extremities after arterial occlusion. Vessels of the circle of Willis, including the communicating collateral arteries, also exhibited unique features in the highland species. Our findings support the hypothesis that species native to high-altitude have undergone genetic selection for abundant collaterals, suggesting that besides providing protection in obstructive disease, collaterals serve a physiological function to optimize oxygen delivery to meet oxygen demand when oxygen is limiting.
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Affiliation(s)
- James E Faber
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
| | - Zachary A Cheviron
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Hua Zhang
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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23
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Pires Monteiro S, Voogd E, Muzzi L, De Vecchis G, Mossink B, Levers M, Hassink G, Van Putten M, Le Feber J, Hofmeijer J, Frega M. Neuroprotective effect of hypoxic preconditioning and neuronal activation in a in vitro human model of the ischemic penumbra. J Neural Eng 2021; 18:036016. [PMID: 33724235 DOI: 10.1088/1741-2552/abe68a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE In ischemic stroke, treatments to protect neurons from irreversible damage are urgently needed. Studies in animal models have shown that neuroprotective treatments targeting neuronal silencing improve brain recovery, but in clinical trials none of these were effective in patients. This failure of translation poses doubts on the real efficacy of treatments tested and on the validity of animal models for human stroke. Here, we established a human neuronal model of the ischemic penumbra by using human induced pluripotent stem cells and we provided an in-depth characterization of neuronal responses to hypoxia and treatment strategies at the network level. APPROACH We generated neurons from induced pluripotent stem cells derived from healthy donor and we cultured them on micro-electrode arrays. We measured the electrophysiological activity of human neuronal networks under controlled hypoxic conditions. We tested the effect of different treatment strategies on neuronal network functionality. MAIN RESULTS Human neuronal networks are vulnerable to hypoxia reflected by a decrease in activity and synchronicity under low oxygen conditions. We observe that full, partial or absent recovery depend on the timing of re-oxygenation and we provide a critical time threshold that, if crossed, is associated with irreversible impairments. We found that hypoxic preconditioning improves resistance to a second hypoxic insult. Finally, in contrast to previously tested, ineffective treatments, we show that stimulatory treatments counteracting neuronal silencing during hypoxia, such as optogenetic stimulation, are neuroprotective. SIGNIFICANCE We presented a human neuronal model of the ischemic penumbra and we provided insights that may offer the basis for novel therapeutic approaches for patients after stroke. The use of human neurons might improve drug discovery and translation of findings to patients and might open new perspectives for personalized investigations.
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Affiliation(s)
- Sara Pires Monteiro
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands
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24
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Urrutia AA, Guan N, Mesa‐Ciller C, Afzal A, Davidoff O, Haase VH. Inactivation of HIF-prolyl 4-hydroxylases 1, 2 and 3 in NG2-expressing cells induces HIF2-mediated neurovascular expansion independent of erythropoietin. Acta Physiol (Oxf) 2021; 231:e13547. [PMID: 32846048 PMCID: PMC7757172 DOI: 10.1111/apha.13547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/23/2020] [Accepted: 08/11/2020] [Indexed: 12/14/2022]
Abstract
AIM NG2 cells in the brain are comprised of pericytes and NG2 glia and play an important role in the execution of cerebral hypoxia responses, including the induction of erythropoietin (EPO) in pericytes. Oxygen-dependent angiogenic responses are regulated by hypoxia-inducible factor (HIF), the activity of which is controlled by prolyl 4-hydroxylase domain (PHD) dioxygenases and the von Hippel-Lindau (VHL) tumour suppressor. However, the role of NG2 cells in HIF-regulated cerebral vascular homeostasis is incompletely understood. METHODS To examine the HIF/PHD/VHL axis in neurovascular homeostasis, we used a Cre-loxP-based genetic approach in mice and targeted Vhl, Epo, Phd1, Phd2, Phd3 and Hif2a in NG2 cells. Cerebral vasculature was assessed by immunofluorescence, RNA in situ hybridization, gene and protein expression analysis, gel zymography and in situ zymography. RESULTS Vhl inactivation led to a significant increase in angiogenic gene and Epo expression. This was associated with EPO-independent expansion of capillary networks in cortex, striatum and hypothalamus, as well as pericyte proliferation. A comparable phenotype resulted from the combined inactivation of Phd2 and Phd3, but not from Phd2 inactivation alone. Concomitant PHD1 function loss led to further expansion of the neurovasculature. Genetic inactivation of Hif2a in Phd1/Phd2/Phd3 triple mutant mice resulted in normal cerebral vasculature. CONCLUSION Our studies establish (a) that HIF2 activation in NG2 cells promotes neurovascular expansion and remodelling independently of EPO, (b) that HIF2 activity in NG2 cells is co-controlled by PHD2 and PHD3 and (c) that PHD1 modulates HIF2 transcriptional responses when PHD2 and PHD3 are inactive.
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Affiliation(s)
- Andrés A. Urrutia
- Department of MedicineVanderbilt University School of MedicineNashvilleTNUSA
- Unidad de Investigación Hospital de Santa CristinaInstituto de Investigación del Hospital Universitario La PrincesaUniversidad Autónoma de MadridMadridSpain
| | - Nan Guan
- Department of MedicineVanderbilt University School of MedicineNashvilleTNUSA
- Division of NephrologyHuashan Hospital and Nephrology Research InstituteFudan UniversityShanghaiChina
| | - Claudia Mesa‐Ciller
- Unidad de Investigación Hospital de Santa CristinaInstituto de Investigación del Hospital Universitario La PrincesaUniversidad Autónoma de MadridMadridSpain
| | - Aqeela Afzal
- Department of NeurosurgeryVanderbilt University School of MedicineNashvilleTNUSA
| | - Olena Davidoff
- Department of MedicineVanderbilt University School of MedicineNashvilleTNUSA
| | - Volker H. Haase
- Department of MedicineVanderbilt University School of MedicineNashvilleTNUSA
- Division of Integrative PhysiologyDepartment of Medical Cell BiologyUppsala UniversitetUppsalaSweden
- Department of Molecular Physiology and Biophysics and Program in Cancer BiologyVanderbilt University School of MedicineNashvilleTNUSA
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25
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Schnichels S, Joachim SC. The inducible nitric oxide synthase-inhibitor 1400W as a potential treatment for retinal diseases. Neural Regen Res 2021; 16:1221-1222. [PMID: 33269785 PMCID: PMC8224120 DOI: 10.4103/1673-5374.300445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Sven Schnichels
- University Eye Hospital Tübingen, Centre for Ophthalmology, Tübingen, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
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26
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Hypoxia and its preconditioning on cardiac and vascular remodelling in experimental animals. Respir Physiol Neurobiol 2020; 285:103588. [PMID: 33253893 DOI: 10.1016/j.resp.2020.103588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/28/2020] [Accepted: 11/12/2020] [Indexed: 11/21/2022]
Abstract
Since oxygen (O2) is indispensable for mammalian life, every cell in the body is endowed with mechanisms to detect and to respond to changes in the O2 levels in the microenvironment. The heart and the brain are the two most vital, life-supporting organs requiring a continuous supply of O2 to sustain their high metabolic rate. On being challenged with hypoxia, maintenance of O2 supply to these organs even at the cost of others becomes a priority. This review describes the cardiovascular, skeletal muscle vascular, pulmonary vascular and cerebrovascular remodelling in face of chronic mild hypoxia exposure and the underlying mechanisms, with special reference to the role of oxidative stress, hypoxia signalling, autonomic nervous mechanisms. The significance of the normalized wall index (NWI) in assessing the remodelling of the vessels particularly of the intramyocardial coronary artery has been underscored. The review also highlights the basic concepts of hypoxic preconditioning and the subsequent protection of the brain against an acute ischemic insult in preclinical studies hinting towards its possible therapeutic potential in the management of ischemic stroke.
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27
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Halder SK, Milner R. Mild hypoxia triggers transient blood-brain barrier disruption: a fundamental protective role for microglia. Acta Neuropathol Commun 2020; 8:175. [PMID: 33115539 PMCID: PMC7592567 DOI: 10.1186/s40478-020-01051-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022] Open
Abstract
We recently demonstrated that when mice are exposed to chronic mild hypoxia (CMH, 8% O2), blood vessels in the spinal cord show transient vascular leak that is associated with clustering and activation of microglia around disrupted vessels. Importantly, microglial depletion profoundly increased hypoxia-induced vascular leak, implying that microglia play a critical role maintaining vascular integrity in the hypoxic spinal cord. The goal of the current study was to examine if microglia play a similar vasculo-protective function in the brain. Employing extravascular fibrinogen leak as an index of blood-brain barrier (BBB) disruption, we found that CMH provoked transient vascular leak in cerebral blood vessels that was associated with activation and aggregation of Mac-1-positive microglia around leaky vessels. Interestingly, CMH-induced vascular leak showed regional selectivity, being much more prevalent in the brainstem and olfactory bulb than the cerebral cortex and cerebellum. Pharmacological depletion of microglia with the colony stimulating factor-1 receptor inhibitor PLX5622, had no effect under normoxic conditions, but markedly increased hypoxia-induced cerebrovascular leak in all regions examined. As in the spinal cord, this was associated with endothelial induction of MECA-32, a marker of leaky CNS endothelium, and greater loss of endothelial tight junction proteins. Brain regions displaying the highest levels of hypoxic-induced vascular leak also showed the greatest levels of angiogenic remodeling, suggesting that transient BBB disruption may be an unwanted side-effect of hypoxic-induced angiogenic remodeling. As hypoxia is common to a multitude of human diseases including obstructive sleep apnea, lung disease, and age-related pulmonary, cardiac and cerebrovascular dysfunction, our findings have important translational implications. First, they point to a potential pathogenic role of chronic hypoxia in triggering BBB disruption and subsequent neurological dysfunction, and second, they demonstrate an important protective role for microglia in maintaining vascular integrity in the hypoxic brain.
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Affiliation(s)
- Sebok K. Halder
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA 92121 USA
| | - Richard Milner
- San Diego Biomedical Research Institute, 10865 Road to the Cure, Suite 100, San Diego, CA 92121 USA
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28
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Zhang H, Rzechorzek W, Aghajanian A, Faber JE. Hypoxia induces de novo formation of cerebral collaterals and lessens the severity of ischemic stroke. J Cereb Blood Flow Metab 2020; 40:1806-1822. [PMID: 32423327 PMCID: PMC7430105 DOI: 10.1177/0271678x20924107] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Pial collaterals provide protection in stroke. Evidence suggests their formation late during gestation (collaterogenesis) is driven by reduced oxygen levels in the cerebral watersheds. The purpose of this study was to determine if collaterogenesis can be re-activated in the adult to induce formation of additional collaterals ("neo-collateral formation", NCF). Mice were gradually acclimated to reduced inspired oxygen (FIO2) and maintained at 12, 10, 8.5 or 7% for two-to-eight weeks. Hypoxemia induced "dose"-dependent NCF and remodeling of native collaterals, and decreased infarct volume after permanent MCA occlusion. In contrast, no formation occurred of addition collateral-like intra-tree anastomoses, PComs, or branches within the MCA tree. Hypoxic NCF, remodeling and infarct protection were durable, i.e. retained for at least six weeks after return to normoxia. Hypoxia increased expression of Hif2α, Vegfa, Rabep2, Angpt2, Tie2 and Cxcr4. Neo-collateral formation was abolished in mice lacking Rabep2, a novel gene involved in VEGFA→Flk1 signaling and required for formation of collaterals during development, and inhibited by knockdown of Vegfa, Flk1 and Cxcr4. Rabep2-dependent NCF was also induced by permanent MCA occlusion. This is the first report that hypoxia induces new pial collaterals to form. Hypoxia- and occlusion-induced neo-collateral formation provide models to study collaterogenesis in the adult.
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Affiliation(s)
- Hua Zhang
- Department of Cell Biology and Physiology, McAllister Heart Institute, Curriculum in Neurobiology, University of North Carolina at Chapel Hill, NC, USA
| | - Wojciech Rzechorzek
- Department of Cell Biology and Physiology, McAllister Heart Institute, Curriculum in Neurobiology, University of North Carolina at Chapel Hill, NC, USA
| | - Amir Aghajanian
- Department of Cell Biology and Physiology, McAllister Heart Institute, Curriculum in Neurobiology, University of North Carolina at Chapel Hill, NC, USA
| | - James E Faber
- Department of Cell Biology and Physiology, McAllister Heart Institute, Curriculum in Neurobiology, University of North Carolina at Chapel Hill, NC, USA
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29
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Sakita M, Murakami S, Nonaka K, Sakamoto R, Saito T, Isobe W, Kumagai S. Different patterns in age-related morphometric alteration of myelinated fibers and capillaries of the tibial nerve: a longitudinal study in normal rats. J Anat 2020; 236:1101-1111. [PMID: 32052433 DOI: 10.1111/joa.13168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 12/11/2022] Open
Abstract
Age-related regression of myelinated fibers in peripheral nerves of the lower limbs is strongly influenced by capillaries and results in balance dysfunction and falls. However, the temporal relationships between alteration patterns of myelinated fibers and capillaries have not yet been clarified. This study aimed to investigate age-related morphological and histological changes of both myelinated fibers and capillaries in peripheral nerves to clarify whether myelinated fibers or capillaries change earlier. Seven male Wistar rats each were randomly selected at 20 weeks (young group), 70 weeks (middle group), and 97 weeks (old group) for histological evaluations. The left and right tibial nerves were removed morphologically and histologically to examine myelinated fibers and capillaries. Axon diameter and myelin thickness were almost unaltered in the middle group compared with the young group but were significantly reduced in the old group when compared with the other two groups. However, the capillary diameter and number of microvascular branch points were substantially reduced in the middle group. The current study demonstrates that myelinated fibers of peripheral nerves show signs of regression in elderly rats, whereas capillaries start to reduce in middle-aged animals. In normal aging of the tibial nerve, capillaries may regress before myelinated fibers.
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Affiliation(s)
- Masahiro Sakita
- Graduate School of Health Sciences, Kyoto Tachibana University, Kyoto, Japan
| | - Shinichiro Murakami
- Department of Physical Therapy, Faculty of Health Care Sciences, Himeji-Dokkyo University, Hyogo, Japan
| | - Koji Nonaka
- Department of Rehabilitation, Faculty of Health Sciences, Naragakuen University, Nara, Japan
| | - Ryuji Sakamoto
- Department of Physical Therapy, Takarazuka University of Medical and Health Care, Hyogo, Japan
| | - Takafumi Saito
- Department of Physical Therapy, Aso Rehabilitation College, Fukuoka, Japan
| | - Wataru Isobe
- Department of Rehabilitation, Mitsubishi Kyoto Hospital, Kyoto, Japan
| | - Shuzo Kumagai
- Laboratory of Health and Exercise Epidemiology, Center for Health Science and Counseling, Kyushu University, Fukuoka, Japan
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30
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A critical role for microglia in maintaining vascular integrity in the hypoxic spinal cord. Proc Natl Acad Sci U S A 2019; 116:26029-26037. [PMID: 31772011 DOI: 10.1073/pnas.1912178116] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypoxic preconditioning reduces disease severity in a mouse model of multiple sclerosis (MS), in part by enhancing the barrier properties of spinal cord blood vessels. Because other studies have shown that similar levels of hypoxia transiently increase permeability of central nervous system (CNS) blood vessels, the goal of this study was to define the impact of chronic mild hypoxia (CMH, 8% O2) on the integrity of spinal cord blood vessels and the responses of neighboring glial cells. Using extravascular fibrinogen as a marker of vascular disruption, we found that CMH triggered transient vascular leak in spinal cord blood vessels, particularly in white matter, which was associated with clustering and activation of Mac-1-positive microglia around disrupted vessels. Microglial depletion with the colony stimulating factor-1 receptor (CSF-1R) inhibitor PLX5622, while having no effect under normoxic conditions, profoundly increased vascular leak in both white and gray matter during CMH, and this was associated with disruption of astrocyte-vascular coupling and enhanced loss of tight junction proteins. Microglial repair of leaky blood vessels was blocked by a peptide that inhibits the interaction between fibrinogen and its Mac-1 integrin receptor. These findings highlight an important role for microglia in maintaining vascular integrity in the hypoxic spinal cord and suggest that a fibrinogen-Mac-1 interaction underpins this response. As relative hypoxia is experienced in many situations including high altitude, lung disease, obstructive sleep apnea, and age-related CNS ischemia/hypoxia, our findings have important implications regarding the critical role of microglia in maintaining vascular integrity in the CNS.
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31
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Effect of Intermittent Hypoxia Training for Dizziness: A Randomized Controlled Trial. J Sport Rehabil 2019; 28:540-543. [PMID: 29584516 DOI: 10.1123/jsr.2017-0341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/25/2018] [Accepted: 03/06/2018] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To study the effect of intermittent hypoxia training (IHT) for dizziness. DESIGN A single-blind, randomized controlled trial. All participants were recruited from a rehabilitation department in an acute university-affiliated hospital. INTERVENTION Participants with dizziness were randomly assigned to 2 groups (IHT group and control group). The Dizziness Handicap Inventory, Activities-specific Balance Confidence Scale, and Vertigo Visual Analog Scale were conducted at baseline, end of the fourth week. RESULTS Among 52 subjects, there were18 males and 34 females, ages 35 to 62 years old (mean [SD] = 46.9 [7.93]). Time length since onset ranged from 12 to 34 months (20.2 [7.15] mo). Dizziness Handicap Inventory, Activities-specific Balance Confidence Scale, Vertigo Visual Analog Scale scores, and attack frequencies of dizziness were improved after IHT intervention in the end of the fourth week. There were significant differences between the IHT group and the control group in the Dizziness Handicap Inventory, Activities-specific Balance Confidence Scale, Vertigo Visual Analog Scale scores, and attack frequencies of dizziness at the end of the fourth week (P < .05). No adverse events occurred during the study. CONCLUSION IHT could improve dizziness after intervention at the end of the fourth week. IHT could be the effective method for treating dizziness.
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32
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Bogorad MI, DeStefano JG, Linville RM, Wong AD, Searson PC. Cerebrovascular plasticity: Processes that lead to changes in the architecture of brain microvessels. J Cereb Blood Flow Metab 2019; 39:1413-1432. [PMID: 31208241 PMCID: PMC6681538 DOI: 10.1177/0271678x19855875] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The metabolic demands of the brain are met by oxygen and glucose, supplied by a complex hierarchical network of microvessels (arterioles, capillaries, and venules). Transient changes in neural activity are accommodated by local dilation of arterioles or capillaries to increase cerebral blood flow and hence nutrient availability. Transport and communication between the circulation and the brain is regulated by the brain microvascular endothelial cells that form the blood-brain barrier. Under homeostatic conditions, there is very little turnover in brain microvascular endothelial cells, and the cerebrovascular architecture is largely static. However, changes in the brain microenvironment, due to environmental factors, disease, or trauma, can result in additive or subtractive changes in cerebrovascular architecture. Additions occur by angiogenesis or vasculogenesis, whereas subtractions occur by vascular pruning, injury, or endothelial cell death. Here we review the various processes that lead to changes in the cerebrovascular architecture, including sustained changes in the brain microenvironment, development and aging, and injury, disease, and repair.
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Affiliation(s)
- Max I Bogorad
- 1 Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.,2 Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jackson G DeStefano
- 1 Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.,2 Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Raleigh M Linville
- 1 Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.,3 Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Andrew D Wong
- 1 Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.,2 Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter C Searson
- 1 Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, USA.,2 Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.,3 Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
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33
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Cohen S, Liu Q, Wright M, Garvin J, Rarick K, Harder D. High glucose conditioned neonatal astrocytes results in impaired mitogenic activity in cerebral microvessel endothelial cells in co-culture. Heliyon 2019; 5:e01795. [PMID: 31193586 PMCID: PMC6536426 DOI: 10.1016/j.heliyon.2019.e01795] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 04/22/2019] [Accepted: 05/20/2019] [Indexed: 11/20/2022] Open
Abstract
Angiogenesis is a highly complex and coordinated process in the brain. Under normal conditions, it is a vital process in growth and development, but under adverse conditions such as diabetes mellitus, it can lead to severe pathology. Astrocytes are a key constituent of the neurovascular unit and contribute to cerebral function, not only bridging the gap between metabolic supplies from blood vessels to neurons, but also regulating angiogenesis. Astrocytes affect angiogenesis by secreting angiogenic factors such as vascular endothelial growth factor (VEGF) into its microenvironment and regulating mitogenic activity in cerebral microvessel endothelial cells (CMEC). We hypothesized that astrocytes conditioned in high glucose media would produce and secrete decreased VEGF which would lead to impaired proliferation, migration, and tube formation of CMEC in vitro. Using neonatal rat astrocytes, we used normal glucose (NG, 5.5mM) vs. high glucose (HG, 25mM) feeding media and measured VEGF message and protein levels as well as secreted VEGF. We co-cultured conditioned astrocytes with isolated rat CMEC and measured mitogenic activity of endothelial cells using BrdU assay, scratch recovery assay, and tube formation assay. HG astrocytes produced and secreted decreased VEGF protein and resulted in impaired mitogenic activity when co-cultured with CMEC as demonstrated by decreased BrdU uptake, decreased scratch recovery, and slower tube formation. Our study provides insight into gliovascular adaptations to increased glucose levels resulting in impaired cellular cross-talk between astrocytes and CMEC which could be one explanation for cerebral microangiopathy seen in diabetic conditions.
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Affiliation(s)
- Susan Cohen
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
- Corresponding author.
| | - Qiuli Liu
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | - Jodi Garvin
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kevin Rarick
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - David Harder
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
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Abstract
The aim of this study was to vascularize brain organoids with a patient's own endothelial cells (ECs). Induced pluripotent stem cells (iPSCs) of one UC Davis patient were grown into whole-brain organoids. Simultaneously, iPSCs from the same patient were differentiated into ECs. On day 34, the organoid was re-embedded in Matrigel with 250 000 ECs. Vascularized organoids were grown in vitro for 3-5 weeks or transplanted into immunodeficient mice on day 54, and animals were perfused on day 68. Coating of brain organoids on day 34 with ECs led to robust vascularization of the organoid after 3-5 weeks in vitro and 2 weeks in vivo. Human CD31-positive blood vessels were found inside and in-between rosettes within the center of the organoid after transplantation. Vascularization of brain organoids with a patient's own iPSC-derived ECs is technically feasible.
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35
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Halder SK, Kant R, Milner R. Chronic mild hypoxia increases expression of laminins 111 and 411 and the laminin receptor α6β1 integrin at the blood-brain barrier. Brain Res 2018; 1700:78-85. [PMID: 30006296 PMCID: PMC6231956 DOI: 10.1016/j.brainres.2018.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/05/2018] [Accepted: 07/09/2018] [Indexed: 11/23/2022]
Abstract
The laminin family of glycoproteins are major constituents of the basal lamina of blood vessels, and play a fundamental role in promoting endothelial differentiation and blood-brain barrier (BBB) stability. Chronic mild hypoxia (CMH), in which mice are exposed to 8% O2 for two weeks, induces a strong vascular remodeling response in the central nervous system (CNS) that includes endothelial proliferation, angiogenesis, arteriogenesis as well as increased expression of tight junction proteins, suggestive of enhanced vascular integrity. As previous studies highlight an important role for laminin in promoting vascular differentiation and BBB stability, the goal of this study was to determine if CMH influences the expression of the laminins and their cell surface receptors in cerebral blood vessels. Our studies revealed that over a 14 day period of CMH, blood vessels in the brain showed strong upregulation of the specific laminin subunits α1 and α4, corresponding to increased expression of laminins 111 and 411 respectively, with no discernible changes in the expression levels of the α2 or α5 laminin subunits. This was accompanied by marked endothelial upregulation of the laminin receptor α6β1 integrin but no alterations in the other laminin receptors α1β1 integrin or dystroglycan. In light of the instructive role for laminins in promoting vascular differentiation and stability, these data suggest that upregulation of the laminin-α6β1 integrin axis is part of the molecular response triggered by mild hypoxia that leads to enhanced BBB stability.
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Affiliation(s)
- Sebok K Halder
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
| | - Ravi Kant
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
| | - Richard Milner
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States.
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36
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Abstract
The human cerebral vasculature originates in the fourth week of gestation and continues to expand and diversify well into the first few years of postnatal life. A key feature of this growth is smooth muscle differentiation, whereby smooth muscle cells within cerebral arteries transform from migratory to proliferative to synthetic and finally to contractile phenotypes. These phenotypic transformations can be reversed by pathophysiological perturbations such as hypoxia, which causes loss of contractile capacity in immature cerebral arteries. In turn, loss of contractility affects all whole-brain cerebrovascular responses, including those involved in flow-metabolism coupling, vasodilatory responses to acute hypoxia and hypercapnia, cerebral autoregulation, and reactivity to activation of perivascular nerves. Future strategies to minimize cerebral injury following hypoxia-ischemic insults in the immature brain might benefit by targeting treatments to preserve and promote contractile differentiation in the fetal cerebrovasculature. This could potentially be achieved through inhibition of receptor tyrosine kinase-mediated growth factors, such as vascular endothelial growth factor and platelet-derived growth factor, which are mobilized by hypoxic and ischemic injury and which facilitate contractile dedifferentiation. Interruption of the effects of other vascular mitogens, such as endothelin and angiotensin-II, and even some miRNA species, also could be beneficial. Future experimental work that addresses these possibilities offers promise to improve current clinical management of neonates who have suffered and survived hypoxic, ischemic, asphyxic, or inflammatory cerebrovascular insults.
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Affiliation(s)
- William J Pearce
- From the Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA.
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Sakita M, Murakami S, Fujino H, Hayashi S, Kameyama K, Saito T, Kumagai S. Remodeling of myelinated fibers and internal capillaries in distal peripheral nerves following aerobic exercise in aged rats. J Appl Physiol (1985) 2018; 125:1051-1061. [DOI: 10.1152/japplphysiol.00257.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to determine whether aerobic exercise (AE) in old age contributes to improving the morphologies of myelinated fibers (MFs) in peripheral nerves as well as capillaries. Furthermore, we investigated whether such processes are associated with complementary activity of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in the circulating blood and peripheral nerve tissue. Fourteen male Wistar rats (age: 95 wk) were randomly divided into moderate AE ( n = 8) and sedentary (SED; n = 6) groups. Rats in the AE group performed treadmill running for 1 h per day for 2 wk, following which the bilateral tibial nerves of the two groups were removed to examine MF and capillary structure. Levels of BDNF and VEGF in the serum and peripheral nerves were analyzed via enzyme-linked immunosorbent assay. Myelin thickness, axon diameter, and capillary luminal diameter were significantly larger in the AE group than in the SED group ( P < 0.0001). Levels of serum BDNF and VEGF were significantly lower and higher, respectively, in the AE group than in the SED group ( P < 0.001). Conversely, BDNF and VEGF levels in tibial nerve tissue were significantly higher, respectively, and lower in the AE group than in the SED group ( P < 0.001). In conclusion, our study indicates that regular AE induces enlargement of the capillaries and thickens the myelin in aged peripheral nerves, likely via a complementary process involving BDNF and VEGF. NEW & NOTEWORTHY Accumulating evidence indicates that age-related sarcopenia is accompanied by the degeneration of myelinated fibers (MFs) in peripheral nerves. Our study indicates that regular aerobic exercise contributes to increased thickness of the myelin surrounding MFs and enlargement of the capillaries, likely via a complementary process involving brain-derived neurotrophic factor and vascular endothelial growth factor. Our findings demonstrate that regular, moderate-intensity aerobic exercise may help to prevent and reverse peripheral nerve regression in older adults.
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Affiliation(s)
- Masahiro Sakita
- Faculty of Health Sciences, Department of Physical Therapy, Kyoto Tachibana University, Kyoto City, Kyoto, Japan
| | - Shinichiro Murakami
- Faculty of Health Care Sciences, Department of Physical Therapy, Himeji-Dokkyo University, Himeji City, Hyogo, Japan
| | - Hidemi Fujino
- Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe City, Hyogo, Japan
| | - Satoshi Hayashi
- Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama City, Okayama, Japan
| | - Kazuyoshi Kameyama
- Department of Occupational Therapy, Hakuhokai Medical Technical School Ako, Ako City, Hyogo, Japan
| | - Takafumi Saito
- Department of Physical Therapy, Aso Rehabilitation College, Hakata Ward, Fukuoka, Japan
| | - Shuzo Kumagai
- Laboratory of Health and Exercise Epidemiology, Center for Health Science and Counseling, Kyushu University, Kasuga City, Fukuoka, Japan
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Halder SK, Kant R, Milner R. Hypoxic pre-conditioning suppresses experimental autoimmune encephalomyelitis by modifying multiple properties of blood vessels. Acta Neuropathol Commun 2018; 6:86. [PMID: 30176931 PMCID: PMC6122733 DOI: 10.1186/s40478-018-0590-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 08/27/2018] [Indexed: 12/26/2022] Open
Abstract
While hypoxic pre-conditioning protects against neurological disease the underlying mechanisms have yet to be fully defined. As chronic mild hypoxia (CMH, 10% O2) triggers profound vascular remodeling in the central nervous system (CNS), the goal of this study was to examine the protective potential of hypoxic pre-conditioning in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS) and then determine how CMH influences vascular integrity and the underlying cellular and molecular mechanisms during EAE. We found that mice exposed to CMH at the same time as EAE induction were strongly protected against the development of EAE progression, as assessed both at the clinical level and at the histopathological level by reduced levels of inflammatory leukocyte infiltration, vascular breakdown and demyelination. Mechanistically, our studies indicate that CMH protects, at least in part, by enhancing several properties of blood vessels that contribute to vascular integrity, including reduced expression of the endothelial activation molecules VCAM-1 and ICAM-1, maintained expression of endothelial tight junction proteins ZO-1 and occludin, and upregulated expression of the leukocyte inhibitory protein laminin-111 in the vascular basement membrane. Taken together, these data suggest that optimization of BBB integrity is an important mechanism underlying the protective effect of hypoxic pre-conditioning.
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Lee S, Kang BM, Kim JH, Min J, Kim HS, Ryu H, Park H, Bae S, Oh D, Choi M, Suh M. Real-time in vivo two-photon imaging study reveals decreased cerebro-vascular volume and increased blood-brain barrier permeability in chronically stressed mice. Sci Rep 2018; 8:13064. [PMID: 30166586 PMCID: PMC6117335 DOI: 10.1038/s41598-018-30875-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/07/2018] [Indexed: 01/15/2023] Open
Abstract
Chronic stress disrupts brain homeostasis and adversely affects the cerebro-vascular system. Even though the effects of chronic stress on brain system have been extensively studied, there are few in vivo dynamic studies on the effects of chronic stress on the cerebro-vascular system. In this study, the effects of chronic stress on cerebral vasculature and BBB permeability were studied using in vivo two-photon (2p) microscopic imaging with an injection of fluorescence-conjugated dextran. Our real-time 2p imaging results showed that chronic stress reduced the vessel diameter and reconstructed vascular volume, regardless of vessel type and branching order. BBB permeability was investigated with two different size of tracers. Stressed animals exhibited a greater BBB permeability to 40-kDa dextran, but not to 70-kDa dextran, which is suggestive of weakened vascular integrity following stress. Molecular analysis revealed significantly higher VEGFa mRNA expression and a reduction in claudin-5. In summary, chronic stress decreases the size of cerebral vessels and increases BBB permeability. These results may suggest that the sustained decrease in cerebro-vascular volume due to chronic stress leads to a hypoxic condition that causes molecular changes such as VEGF and claudin-5, which eventually impairs the function of BBB.
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Affiliation(s)
- Sohee Lee
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
| | - Bok-Man Kang
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Jae Hwan Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Jiwoong Min
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Hyung Seok Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Hyunwoo Ryu
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Hyejin Park
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.,Department of Biological Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Sungjun Bae
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Daehwan Oh
- Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Myunghwan Choi
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Minah Suh
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea. .,Department of Biomedical Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea. .,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea. .,Samsung Advanced Institute of Health Science and Technology (SAIHST), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.
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Ducsay CA, Goyal R, Pearce WJ, Wilson S, Hu XQ, Zhang L. Gestational Hypoxia and Developmental Plasticity. Physiol Rev 2018; 98:1241-1334. [PMID: 29717932 PMCID: PMC6088145 DOI: 10.1152/physrev.00043.2017] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Hypoxia is one of the most common and severe challenges to the maintenance of homeostasis. Oxygen sensing is a property of all tissues, and the response to hypoxia is multidimensional involving complicated intracellular networks concerned with the transduction of hypoxia-induced responses. Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. Hypoxia during gestation impacts both the mother and fetal development through interactions with an individual's genetic traits acquired over multiple generations by natural selection and changes in gene expression patterns by altering the epigenetic code. Changes in the epigenome determine "genomic plasticity," i.e., the ability of genes to be differentially expressed according to environmental cues. The genomic plasticity defined by epigenomic mechanisms including DNA methylation, histone modifications, and noncoding RNAs during development is the mechanistic substrate for phenotypic programming that determines physiological response and risk for healthy or deleterious outcomes. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue. The complex molecular and epigenetic interactions that may impact an individual's physiology and developmental programming of health and disease later in life are discussed.
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Affiliation(s)
- Charles A. Ducsay
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Ravi Goyal
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - William J. Pearce
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Sean Wilson
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Xiang-Qun Hu
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Lubo Zhang
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
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41
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Yue Y, Xu D, Wang Y, Wang X, Xia F. Effect of inducible nitric oxide synthase and neuropeptide Y in plasma and placentas from intrahepatic cholestasis of pregnancy. J Obstet Gynaecol Res 2018; 44:1377-1383. [PMID: 29956420 DOI: 10.1111/jog.13681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 04/18/2018] [Indexed: 12/27/2022]
Abstract
AIM To analyze inducible nitric oxide synthase (iNOS) and neuropeptide Y (NPY) expression in maternal plasma and placentas of human with intrahepatic cholestasis of pregnancy (ICP). METHODS The plasma and placentas were collected from 35 women with normal pregnancies and 33 women with ICP. Enzyme-linked immunosorbent assays were used to investigate maternal plasma iNOS and NPY levels. The mRNA levels and cell-specific localization of iNOS and NPY were determined by quantitative PCR, Western Blotting and immunohistochemical analysis in placentas. RESULTS In human placentas, it revealed iNOS and NPY were mainly localized in syncytiotrophoblast, cytotrophoblastin and vascular endothelium cells using immunohistochemistry analysis. iNOS protein and mRNA expression in ICP maternal plasma and placental tissue were significantly lower than in control groups (P <0.01). In maternal plasma and placentas tissue from ICP patients, a marked up-regulation of NPY protein and mRNA expression were observed (P <0.01). CONCLUSION iNOS and NPY may play a role in the effect of maternal cholestasis on the placenta. The down-regulation of iNOS and up-regulation of NPY in ICP may influence the blood flow of the utero-placental-fetal unit, which may play a significant role in poor fetoplacental vascular perfusion, acute hypoxia and adverse pregnancy outcomes.
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Affiliation(s)
- Yongfei Yue
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of SooChow University, Suzhou, China.,Department of Obstetrics and Gynecology, Suzhou Municipal Hospital Affiliated to Nanjing Medical University, Suzhou, China
| | - Duo Xu
- Shenzhen Maternity and Child Health Care Hospital, Southern Medical University, Shenzhen, China
| | - Yun Wang
- Department of Obstetrics and Gynecology, Suzhou Municipal Hospital Affiliated to Nanjing Medical University, Suzhou, China
| | - Xiaoyan Wang
- Department of Obstetrics and Gynecology, Suzhou Municipal Hospital Affiliated to Nanjing Medical University, Suzhou, China
| | - Fei Xia
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of SooChow University, Suzhou, China
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42
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Kanno I, Seki C, Takuwa H, Jin ZH, Boturyn D, Dumy P, Furukawa T, Saga T, Ito H, Masamoto K. Positron emission tomography of cerebral angiogenesis and TSPO expression in a mouse model of chronic hypoxia. J Cereb Blood Flow Metab 2018; 38:687-696. [PMID: 28128020 PMCID: PMC5888851 DOI: 10.1177/0271678x16689800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The present study aimed to examine whether positron emission tomography (PET) could evaluate cerebral angiogenesis. Mice were housed in a hypoxic chamber with 8-9% oxygen for 4, 7, and 14 days, and the angiogenic responses were evaluated with a radiotracer, 64Cu-cyclam-RAFT-c(-RGDfK-)4, which targeted αVβ3 integrin and was imaged with PET. The PET imaging results showed little uptake during all of the hypoxic periods. Immunofluorescence staining of the β3 integrin, CD61, revealed weak expression, while the microvessel density assessed by CD31 staining increased with the hypoxic duration. These observations suggest that the increased vascular density originated from other types of vascular remodeling, unlike angiogenic sprouting. We then searched for any signs of vascular remodeling that could be detected using PET. PET imaging of 11C-PK11195, a marker of the 18-kDa translocator protein (TSPO), revealed a transient increase at day 4 of hypoxia. Because the immunofluorescence of glial markers showed unchanged staining over the early phase of hypoxia, the observed upregulation of TSPO expression probably originated from non-glial cells (e.g. vascular cells). In conclusion, a transient increase in TSPO probe uptake was detected with PET at only the early phase of hypoxia, which indicates an early sign of vascular remodeling induced by hypoxia.
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Affiliation(s)
- Iwao Kanno
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Chie Seki
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Hiroyuki Takuwa
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Zhao-Hui Jin
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Didier Boturyn
- 2 Département de Chimie Moléculaire, Université Grenoble Alpes, Grenoble, France
| | - Pascal Dumy
- 3 Institut des Biomolécules Max Mousseron, École Nationale Supérieure de Chimie de Montpellier, Montpellier, France
| | - Takako Furukawa
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Tsuneo Saga
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Hiroshi Ito
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Kazuto Masamoto
- 1 Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.,4 Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo, Japan
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Halder SK, Kant R, Milner R. Chronic mild hypoxia promotes profound vascular remodeling in spinal cord blood vessels, preferentially in white matter, via an α5β1 integrin-mediated mechanism. Angiogenesis 2018; 21:251-266. [PMID: 29299782 DOI: 10.1007/s10456-017-9593-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 12/26/2017] [Indexed: 12/15/2022]
Abstract
Spinal cord injury (SCI) leads to rapid destruction of neuronal tissue, resulting in devastating motor and sensory deficits. This is exacerbated by damage to spinal cord blood vessels and loss of vascular integrity. Thus, approaches that protect existing blood vessels or stimulate the growth of new blood vessels might present a novel approach to minimize loss or promote regeneration of spinal cord tissue following SCI. In light of the remarkable power of chronic mild hypoxia (CMH) to stimulate vascular remodeling in the brain, the goal of this study was to examine how CMH (8% O2 for up to 7 days) affects blood vessel remodeling in the spinal cord. We found that CMH promoted the following: (1) endothelial proliferation and increased vascularity as a result of angiogenesis and arteriogenesis, (2) increased vascular expression of the angiogenic extracellular matrix protein fibronectin as well as concomitant increases in endothelial expression of the fibronectin receptor α5β1 integrin, (3) strongly upregulated endothelial expression of the tight junction proteins claudin-5, ZO-1 and occludin and (4) astrocyte activation. Of note, the vascular remodeling changes induced by CMH were more extensive in white matter. Interestingly, hypoxic-induced vascular remodeling in spinal cord blood vessels was markedly attenuated in mice lacking endothelial α5 integrin expression (α5-EC-KO mice). Taken together, these studies demonstrate the considerable remodeling potential of spinal cord blood vessels and highlight an important angiogenic role for the α5β1 integrin in promoting endothelial proliferation. They also imply that stimulation of the α5β1 integrin or controlled use of mild hypoxia might provide new approaches for promoting angiogenesis and improving vascular integrity in spinal cord blood vessels.
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Affiliation(s)
- Sebok K Halder
- Department of Molecular Medicine, MEM-132, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Ravi Kant
- Department of Molecular Medicine, MEM-132, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Richard Milner
- Department of Molecular Medicine, MEM-132, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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44
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Chen R, Liu Y, Su Q, Yang Y, Wang L, Ma S, Yan J, Xue F, Wang J. Hypoxia stimulates proliferation of rat neural stem/progenitor cells by regulating mir-21: an in vitro study. Neurosci Lett 2017; 661:71-76. [DOI: 10.1016/j.neulet.2017.09.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 09/15/2017] [Accepted: 09/18/2017] [Indexed: 12/17/2022]
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45
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Wong E, Yang B, Du L, Ho WH, Lau C, Ke Y, Chan YS, Yung WH, Wu EX. The multi-level impact of chronic intermittent hypoxia on central auditory processing. Neuroimage 2017; 156:232-239. [PMID: 28528846 DOI: 10.1016/j.neuroimage.2017.05.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/07/2017] [Accepted: 05/16/2017] [Indexed: 12/21/2022] Open
Abstract
During hypoxia, the tissues do not obtain adequate oxygen. Chronic hypoxia can lead to many health problems. A relatively common cause of chronic hypoxia is sleep apnea. Sleep apnea is a sleep breathing disorder that affects 3-7% of the population. During sleep, the patient's breathing starts and stops. This can lead to hypertension, attention deficits, and hearing disorders. In this study, we apply an established chronic intermittent hypoxemia (CIH) model of sleep apnea to study its impact on auditory processing. Adult rats were reared for seven days during sleeping hours in a gas chamber with oxygen level cycled between 10% and 21% (normal atmosphere) every 90s. During awake hours, the subjects were housed in standard conditions with normal atmosphere. CIH treatment significantly reduces arterial oxygen partial pressure and oxygen saturation during sleeping hours (relative to controls). After treatment, subjects underwent functional magnetic resonance imaging (fMRI) with broadband sound stimulation. Responses are observed in major auditory centers in all subjects, including the auditory cortex (AC) and auditory midbrain. fMRI signals from the AC are statistically significantly increased after CIH by 0.13% in the contralateral hemisphere and 0.10% in the ipsilateral hemisphere. In contrast, signals from the lateral lemniscus of the midbrain are significantly reduced by 0.39%. Signals from the neighboring inferior colliculus of the midbrain are relatively unaffected. Chronic hypoxia affects multiple levels of the auditory system and these changes are likely related to hearing disorders associated with sleep apnea.
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Affiliation(s)
- Eddie Wong
- Department of Physics and Materials Science, The City University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Bin Yang
- Department of Physics and Materials Science, The City University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Department of Radiology, Children's Hospital of Fudan University, Shanghai, People's Republic of China
| | - Lida Du
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Wai Hong Ho
- Department of Physics and Materials Science, The City University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Condon Lau
- Department of Physics and Materials Science, The City University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China.
| | - Ya Ke
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Ying Shing Chan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Wing Ho Yung
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
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Bohn KA, Adkins CE, Nounou MI, Lockman PR. Inhibition of VEGF and Angiopoietin-2 to Reduce Brain Metastases of Breast Cancer Burden. Front Pharmacol 2017; 8:193. [PMID: 28443023 PMCID: PMC5387068 DOI: 10.3389/fphar.2017.00193] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/24/2017] [Indexed: 11/13/2022] Open
Abstract
For metastases in the central nervous system, angiogenesis enhances metastatic potential and promotes progression. Primary factors which drive vessel growth are vascular endothelial growth factor (VEGF) and angiopoietin-2. Preclinical models show inhibition of either factor reduces metastases spread and inhibits growth. This work sets out to answer two questions in a preclinical mouse model. First, whether the combined inhibition of VEGF and angiopoietin-2, reduces passive permeability and limits drug uptake into brain metastases; and second, whether this inhibition reduces metastases burden in brain. We observed combinatorial inhibition of VEGF and angiopoietin-2, decreased (p < 0.05) angiogenesis and vascular branching in an aortic ring assay and decreased (p < 0.05) endothelial wound closure times. Using a brain metastases of breast cancer model (induced by intracardiac injections of brain seeking MDA-MB-231Br cells or 4T1Br cells), we observed, similar to VEGF, angiopoetin-2 expression correlates to increased angiogenesis (p < 0.05) and increased lesion permeability. To determine efficacy, animals were administered bevacizumab plus L1-10 (angiopoietin inhibitor) twice per week until neurological symptoms developed. Lesion permeability significantly decreased by ∼50% (p < 0.05) compared to untreated lesions, but remained ∼25% greater (p < 0.0%) than brain. In subsequent experiments, animals were administered similar regimens but sacrificed on day 32. The number of metastatic lesions developed was significantly (p < 0.001) reduced in the bevacizumab group (56%) and combination group (86%). Lesions’ size was reduced in bevacizumab treated lesions (∼67%) and bevacizumab and L1-10 treated lesions (∼78%) developing area < 0.5 mm2. In summary, combinatorial inhibition of VEGF and angiopoietin reduces lesion permeability and brain metastatic burden.
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Affiliation(s)
- Kaci A Bohn
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, AmarilloTX, USA.,Department of Pharmaceutical Sciences, College of Pharmacy, Harding University, SearcyAR, USA
| | - Chris E Adkins
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, AmarilloTX, USA.,Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University Health Sciences Center, MorgantownWV, USA.,Department of Pharmaceutical Sciences, South University, SavannahGA, USA
| | - Mohamed I Nounou
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, AmarilloTX, USA.,Department of Pharmaceutical Sciences, Appalachian College of Pharmacy, OakwoodVA, USA.,Department of Pharmaceutics, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt.,Department of Pharmaceutical Sciences, School of Pharmacy, University of Saint Joseph, HartfordCT, USA
| | - Paul R Lockman
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, AmarilloTX, USA
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Olaithe M, Bucks RS, Hillman DR, Eastwood PR. Cognitive deficits in obstructive sleep apnea: Insights from a meta-review and comparison with deficits observed in COPD, insomnia, and sleep deprivation. Sleep Med Rev 2017; 38:39-49. [PMID: 28760549 DOI: 10.1016/j.smrv.2017.03.005] [Citation(s) in RCA: 191] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 03/22/2017] [Accepted: 03/22/2017] [Indexed: 11/19/2022]
Abstract
Obstructive sleep apnea (OSA) is a nocturnal breathing disorder that is associated with cognitive impairment. The primary determinants of cognitive deficits in OSA are thought to be sleep disruption and blood gas abnormalities. Cognitive impairment is also seen in other disorders that are characterised primarily by sleep disturbance (e.g., sleep restriction/deprivation, insomnia) or hypoxia/hypercarbia (e.g., chronic obstructive pulmonary disease (COPD)). Assessment of the cognitive deficits observed in these other disorders could help better define the mechanisms underlying cognitive deficits in OSA. This study utilised meta-review methodology to examine the findings from systematic reviews and meta-analyses of the effects of untreated OSA, COPD, insomnia, and sleep deprivation on cognitive function in adults, compared with norms or controls. Eighteen papers met inclusion criteria: seven in OSA, two in insomnia, five in COPD, and four in sleep deprivation. OSA and COPD were both accompanied by deficits in attention, memory, executive function, psychomotor function, and language abilities, suggesting that hypoxia/hypercarbia may be an important determinant of deficits in these domains in OSA. Both OSA and sleep deprivation studies were accompanied by deficits in attention and memory, suggesting that short-term sleep disturbance in OSA may contribute to deficits in these domains. Visuospatial deficits were unique to OSA, suggesting the contribution of a mechanism other than sleep disturbance and hypoxia/hypercarbia to this problem. Our findings suggest that the cognitive deficits associated with untreated OSA are multidimensional, with different physiological disturbances responsible for differing cognitive problems.
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Affiliation(s)
- Michelle Olaithe
- School of Psychological Science, University of Western Australia, Perth, Australia; Centre for Sleep Science, School of Anatomy, Physiology and Human Biology, Perth, Australia.
| | - Romola S Bucks
- School of Psychological Science, University of Western Australia, Perth, Australia
| | - David R Hillman
- Centre for Sleep Science, School of Anatomy, Physiology and Human Biology, Perth, Australia
| | - Peter R Eastwood
- Centre for Sleep Science, School of Anatomy, Physiology and Human Biology, Perth, Australia
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Zhang J, Chen J, Fan C, Li J, Lin J, Yang T, Fan M. Alteration of Spontaneous Brain Activity After Hypoxia-Reoxygenation: A Resting-State fMRI Study. High Alt Med Biol 2017; 18:20-26. [PMID: 28266873 DOI: 10.1089/ham.2016.0083] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Zhang, Jiaxing, Ji Chen, Cunxiu Fan, Jinqiang Li, Jianzhong Lin, Tianhe Yang, and Ming Fan. Alteration of spontaneous brain activity after hypoxia-reoxygenation: A resting-state fMRI study. High Alt Med Biol. 18:20-26, 2017.-The present study was designed to investigate the effect of hypoxia-reoxygenation on the spontaneous neuronal activity in brain. Sixteen sea-level (SL) soldiers (20.5 ± 0.7 years), who garrisoned the frontiers in high altitude (HA) (2300-4400 m) for two years and subsequently descended to sea level for one to seven days, were recruited. Control group consisted of 16 matched SL natives. The amplitude of low-frequency fluctuations (ALFF) of regional brain functional magnetic resonance imaging signal in resting state and functional connectivity (FC) between brain regions was analyzed. HA subjects showed significant increases of ALFF at several sites within the bilateral occipital cortices and significant decreases of ALFF in the right anterior insula and extending to the caudate, putamen, inferior frontal orbital cortex, temporal pole, and superior temporal gyrus; lower ALFF values in the right insula were positively correlated with low respiratory measurements. The right insula in HA subjects had increases of FC with the right superior temporal gyrus, postcentral gyrus, rolandic operculum, supramarginal gyrus, and inferior frontal triangular area. We thus demonstrated that hypoxia-reoxygenation had influence on the spontaneous neuronal activity in brain. The decrease of insular neuronal activity may be related to the reduction of ventilatory drive, while the increase of FC with insula may indicate a central compensation.
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Affiliation(s)
- Jiaxing Zhang
- 1 Department of Physiology, Medical College of Xiamen University , Xiamen, China
| | - Ji Chen
- 1 Department of Physiology, Medical College of Xiamen University , Xiamen, China
| | - Cunxiu Fan
- 1 Department of Physiology, Medical College of Xiamen University , Xiamen, China
| | - Jinqiang Li
- 2 Department of Clinical Psychology, Gulangyu Sanatorium of PLA , Xiamen, China
| | - Jianzhong Lin
- 3 Magnetic Resonance Center, Zhongshan Hospital Xiamen University , Xiamen, China
| | - Tianhe Yang
- 3 Magnetic Resonance Center, Zhongshan Hospital Xiamen University , Xiamen, China
| | - Ming Fan
- 4 Department of Cognitive Sciences, Institute of Basic Medical Sciences , Beijing, China
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Xu K, Sun X, Benderro GF, Tsipis CP, LaManna JC. Gender differences in hypoxic acclimatization in cyclooxygenase-2-deficient mice. Physiol Rep 2017; 5:5/4/e13148. [PMID: 28242826 PMCID: PMC5328777 DOI: 10.14814/phy2.13148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/13/2017] [Accepted: 01/16/2017] [Indexed: 01/02/2023] Open
Abstract
The aim of this study was to determine the effect of cyclooxygenase‐2 (COX‐2) gene deletion on the adaptive responses during prolonged moderate hypobaric hypoxia. Wild‐type (WT) and COX‐2 knockout (KO) mice of both genders (3 months old) were exposed to hypobaric hypoxia (~0.4 ATM) or normoxia for 21 days and brain capillary densities were determined. Hematocrit was measured at different time intervals; brain hypoxia‐inducible factor ‐1α (HIF‐1α), angiopoietin 2 (Ang‐2), brain erythropoietin (EPO), and kidney EPO were measured under normoxic and hypoxic conditions. There were no gender differences in hypoxic acclimatization in the WT mice and similar adaptive responses were observed in the female KO mice. However, the male KO mice exhibited progressive vulnerability to prolonged hypoxia. Compared to the WT and female KO mice, the male COX‐2 KO mice had significantly lower survival rate and decreased erythropoietic and polycythemic responses, diminished cerebral angiogenesis, decreased brain accumulation of HIF‐1α, and attenuated upregulation of VEGF, EPO, and Ang‐2 during hypoxia. Our data suggest that there are physiologically important gender differences in hypoxic acclimatization in COX‐2‐deficient mice. The COX‐2 signaling pathway appears to be required for acclimatization in oxygen‐limiting environments only in males, whereas female COX‐2‐deficient mice may be able to access COX‐2‐independent mechanisms to achieve hypoxic acclimatization.
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Affiliation(s)
- Kui Xu
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Xiaoyan Sun
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Girriso F Benderro
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Constantinos P Tsipis
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - Joseph C LaManna
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
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Zeng ZY, Gui C, Li L, Wei XM. Effects of Percutaneous Coronary Intervention on Serum Angiopoietin-2 in Patients with Coronary Heart Disease. Chin Med J (Engl) 2017; 129:631-5. [PMID: 26960364 PMCID: PMC4804407 DOI: 10.4103/0366-6999.177968] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background: Angiopoietin-2 (Ang-2) plays a crucial role in hypoxia-induced angiogenesis and is expressed only in sites of vascular remodeling. Ang-2 expression can be regulated by hypoxia inducible factors and other regulators with exposure to hypoxia. The objective of this study was to investigate the influence of percutaneous coronary intervention (PCI) on serum Ang-2 concentrations, and analyze the correlation between serum Ang-2 and the severity of coronary artery stenosis in patients with coronary heart disease (CHD). Methods: Sixty-four patients with CHD were selected as the study group, each undergone PCI. Thirty-two healthy subjects were selected as the control group. Pre-PCI and post-PCI serum Ang-2 were measured by enzyme-linked immunosorbent assay. The severity of coronary artery stenosis was evaluated using angiographic Gensini scores, and the coronary collateral vessels were scored according to Rentrop's classification. Results: Concentrations of pre-PCI serum Ang-2 in the study group were significantly higher than those in the control group (4625.06 ± 1838.06 vs. 1945.74 ± 1588.17 pg/ml, P < 0.01); however, concentrations of post-PCI serum Ang-2 were significantly lower than those of pre-PCI (3042.63 ± 1845.33 pg/ml vs. 4625.06 ± 1838.06 pg/ml, P < 0.01). Concentrations of pre-PCI serum Ang-2 were significantly correlated with Gensini scores (r = 0.488, P < 0.01); however, the decrease in serum Ang-2 after PCI was not correlated with Gensini scores, coronary collateral vessel grading, or left ventricular ejection fraction. Conclusions: Serum Ang-2 concentrations significantly increased in patients with CHD, and PCI treatment significantly decreased these concentrations. Serum Ang-2 concentrations, but not the decrease in serum Ang-2 concentrations, were significantly correlated with the severity of coronary artery stenosis. These results suggested that Ang-2 may be a biomarker of myocardial ischemia and vessel remodeling.
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Affiliation(s)
| | - Chun Gui
- Department of Cardiology, The First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, China
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