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Hu S, Yang B, Shu S, He X, Sang H, Fan X, Zhang H. Targeting Pericytes for Functional Recovery in Ischemic Stroke. Neuromolecular Med 2023; 25:457-470. [PMID: 37166748 DOI: 10.1007/s12017-023-08748-z] [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: 02/24/2023] [Accepted: 05/03/2023] [Indexed: 05/12/2023]
Abstract
Pericytes surrounding endothelial cells in the capillaries are emerging as an attractive cell resource, which can show a large variety of functions in ischemic stroke, including preservation of the blood-brain barrier, regulation of immune function, and support for cerebral vasculature. These functions have been fully elucidated in previous studies. However, in recent years, increasing evidence has shown that pericytes play an important role in neurological recovery after ischemic stroke due to their regenerative function which can be summarized in two aspects according to current discoveries, one is that pericytes are thought to be multipotential themselves, and the other is that pericytes can promote the differentiation of oligodendrocyte progenitor cells (OPCs). Considering the neuroprotective treatment for stroke has not been much progressed in recent years, new therapies targeting pericytes may be a future direction. Here, we will review the beneficial effects of pericytes in ischemic stroke from two directions: the barrier and vascular functions and the regenerative functions of pericytes.
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Affiliation(s)
- Shuqi Hu
- Department of Neurology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, Zhejiang, China
| | - Bingjie Yang
- Department of Neurology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China
| | - Song Shu
- Department of Neurology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, Zhejiang, China
| | - Xudong He
- Department of Neurology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, Zhejiang, China
| | - Hongfei Sang
- Department of Neurology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, Zhejiang, China
| | - Xuemei Fan
- Department of Neurology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, Zhejiang, China
| | - Hao Zhang
- Department of Neurology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, Zhejiang, China.
- Department of Neurology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China.
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2
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Reyes Del Paso GA, Montoro CI, Jennings JR, Duschek S. Experimental carotid baroreceptor stimulation reduces blood flow velocities in the anterior and middle cerebral arteries of healthy individuals. J Physiol Sci 2023; 73:13. [PMID: 37312034 DOI: 10.1186/s12576-023-00871-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 06/07/2023] [Indexed: 06/15/2023]
Abstract
This study investigated effects of experimental baroreceptor stimulation on bilateral blood flow velocities in the anterior and middle cerebral arteries (ACA and MCA) using functional transcranial Doppler sonography. Carotid baroreceptors were stimulated by neck suction in 33 healthy participants. Therefore, negative pressure (- 50 mmHg) was applied; neck pressure (+ 10 mmHg) was used as a control condition. Heart rate (HR) and blood pressure (BP) were also continuously recorded. Neck suction led to reductions in bilateral ACA and MCA blood flow velocities, which accompanied the expected HR and BP decreases; HR and BP decreases correlated positively with the ACA flow velocity decline. The observations suggest reduction of blood flow in the perfusion territories of the ACA and MCA during baroreceptor stimulation. Baroreceptor-related HR and BP decreases may contribute to the cerebral blood flow decline. The findings underline the interaction between peripheral and cerebral hemodynamic regulation in autoregulatory control of cerebral perfusion.
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Affiliation(s)
| | | | - J Richard Jennings
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Stefan Duschek
- UMIT TIROL - University for Health Sciences and Technology, Hall in Tirol, Austria
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3
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Mehra A, Gomez F, Bischof H, Diedrich D, Laudanski K. Cortical Spreading Depolarization and Delayed Cerebral Ischemia; Rethinking Secondary Neurological Injury in Subarachnoid Hemorrhage. Int J Mol Sci 2023; 24:9883. [PMID: 37373029 DOI: 10.3390/ijms24129883] [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: 04/04/2023] [Revised: 05/15/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023] Open
Abstract
Poor outcomes in Subarachnoid Hemorrhage (SAH) are in part due to a unique form of secondary neurological injury known as Delayed Cerebral Ischemia (DCI). DCI is characterized by new neurological insults that continue to occur beyond 72 h after the onset of the hemorrhage. Historically, it was thought to be a consequence of hypoperfusion in the setting of vasospasm. However, DCI was found to occur even in the absence of radiographic evidence of vasospasm. More recent evidence indicates that catastrophic ionic disruptions known as Cortical Spreading Depolarizations (CSD) may be the culprits of DCI. CSDs occur in otherwise healthy brain tissue even without demonstrable vasospasm. Furthermore, CSDs often trigger a complex interplay of neuroinflammation, microthrombi formation, and vasoconstriction. CSDs may therefore represent measurable and modifiable prognostic factors in the prevention and treatment of DCI. Although Ketamine and Nimodipine have shown promise in the treatment and prevention of CSDs in SAH, further research is needed to determine the therapeutic potential of these as well as other agents.
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Affiliation(s)
- Ashir Mehra
- Department of Neurology, University of Missouri, Columbia, MO 65212, USA
| | - Francisco Gomez
- Department of Neurology, University of Missouri, Columbia, MO 65212, USA
| | - Holly Bischof
- Penn Presbyterian Medical Center, Philadelphia, PA 19104, USA
| | - Daniel Diedrich
- Department of Anesthesiology and Perioperative Care, Mayo Clinic, Rochester, MN 55905, USA
| | - Krzysztof Laudanski
- Department of Anesthesiology and Perioperative Care, Mayo Clinic, Rochester, MN 55905, USA
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4
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Moezzi SMI, Javadi P, Mozafari N, Ashrafi H, Azadi A. Metformin-loaded nanoerythrosomes: An erythrocyte-based drug delivery system as a therapeutic tool for glioma. Heliyon 2023; 9:e17082. [PMID: 37484272 PMCID: PMC10361227 DOI: 10.1016/j.heliyon.2023.e17082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/25/2023] Open
Abstract
Glioma is an intra-cranial malignancy with the origin of neural stem cells or precursor cells, the most prevalent brain tumor worldwide. Glioblastoma, the fourth-grade glioma, is a common brain tumor whose incidence rate is 5-7 people per 100,000 populations annually. Despite their high mortality rate, all efforts for treatment have yet to achieve any desirable clinical outcome. The Wnt signaling pathway is a conserved pathway among species that seems to be a candidate for cancer therapy by its inhibition. Metformin is a known inhibitor of the Wnt signaling pathway. Its effects on glioma treatment have been observed in cellular, animal, and clinical experiments. Nanoerythrosomes are drug carriers obtained from the cellular membrane of red blood cells in nano size which can offer several characteristics to deliver metformin to brain tumors. They are good at loading and carrying hydrophilic drugs, they can protect metformin from its metabolizing enzymes, which are present in the blood-brain barrier, and they can extend the period of metformin presence in circulation. In this study, nanoerythrosomes were prepared by using the hypotonic buffer. They had particle sizes in the range of 97.1 ± 34.2 nm, and their loading efficiency and loading capacity were 72.6% and 1.66%, respectively. Nanoerythrosomes could reserve metformin in their structure for a long time, and only 50% of metformin was released after 30 h. Moreover, they released metformin at a low and approximately constant rate. Besides, nanoerythrosomes could tolerate various kinds of stress and maintain most of the drug in their structure. Altogether, nanoerythrosome can be a suitable drug delivery system to deliver therapeutic amounts of metformin to various tissues.
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Affiliation(s)
- Seyed Mohammad Iman Moezzi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutics, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Parisa Javadi
- Department of Nanomedicine, School of Novel Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Negin Mozafari
- Department of Pharmaceutics, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hajar Ashrafi
- Department of Pharmaceutics, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Azadi
- Department of Pharmaceutics, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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5
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Ji Y, Wang L, Ding H, Tian Q, Fan K, Shi D, Yu C, Qin W. Aberrant neurovascular coupling in Leber's hereditary optic neuropathy: Evidence from a multi-model MRI analysis. Front Neurosci 2023; 16:1050772. [PMID: 36703998 PMCID: PMC9871937 DOI: 10.3389/fnins.2022.1050772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
The study aimed to investigate the neurovascular coupling abnormalities in Leber's hereditary optic neuropathy (LHON) and their associations with clinical manifestations. Twenty qualified acute Leber's hereditary optic neuropathy (A-LHON, disease duration ≤ 1 year), 29 chronic Leber's hereditary optic neuropathy (C-LHON, disease duration > 1 year), as well as 37 healthy controls (HCs) were recruited. The neurovascular coupling strength was quantified as the ratio between regional homogeneity (ReHo), which represents intrinsic neuronal activity and relative cerebral blood flow (CBF), representing microcirculatory blood supply. A one-way analysis of variance was used to compare intergroup differences in ReHo/CBF ratio with gender and age as co-variables. Pearson's Correlation was used to clarify the association between ReHo, CBF, and neurovascular coupling strength. Furthermore, we applied linear and exponential non-linear regression models to explore the associations among ReHo/CBF, disease duration, and neuro-ophthalmological metrics. Compared with HCs, A_LHON, and C_LHON patients demonstrated a higher ReHo/CBF ratio than the HCs in the bilateral primary visual cortex (B_CAL), which was accompanied by reduced CBF while preserved ReHo. Besides, only C_LHON had a higher ReHo/CBF ratio and reduced CBF in the left middle temporal gyrus (L_MTG) and left sensorimotor cortex (L_SMC) than the HCs, which was accompanied by increased ReHo in L_MTG (p < 1.85e-3, Bonferroni correction). A-LHON and C-LHON showed a negative Pearson correlation between ReHo/CBF ratio and CBF in B_CAL, L_SMC, and L_MTG. Only C_LHON showed a weak positive correlation between ReHo/CBF ratio and ReHo in L_SMC and L_MTG (p < 0.05, uncorrected). Finally, disease duration was positively correlated with ReHo/CBF ratio of L_SMC (Exponential: Radj2 = 0.23, p = 8.66e-4, Bonferroni correction). No statistical correlation was found between ReHo/CBF ratio and neuro-ophthalmological metrics (p > 0.05, Bonferroni correction). Brain neurovascular "dyscoupling" within and outside the visual system might be an important neurological mechanism of LHON.
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Affiliation(s)
- Yi Ji
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Ling Wang
- Department of Medical Imaging, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Hao Ding
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China,School of Medical Imaging, Tianjin Medical University, Tianjin, China
| | - Qin Tian
- Department of Medical Imaging, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Ke Fan
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People’s Hospital, Zhengzhou University People’s Hospital, Zhengzhou, China
| | - Dapeng Shi
- Department of Medical Imaging, Henan Provincial People’s Hospital, Zhengzhou, China,*Correspondence: Dapeng Shi,
| | - Chunshui Yu
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China,Chunshui Yu,
| | - Wen Qin
- Tianjin Key Lab of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China,Wen Qin,
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Wei WJ, Wang YC, Guan X, Chen WG, Liu J. A neurovascular unit-on-a-chip: culture and differentiation of human neural stem cells in a three-dimensional microfluidic environment. Neural Regen Res 2022; 17:2260-2266. [PMID: 35259847 PMCID: PMC9083144 DOI: 10.4103/1673-5374.337050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Biological studies typically rely on a simple monolayer cell culture, which does not reflect the complex functional characteristics of human tissues and organs, or their real response to external stimuli. Microfluidic technology has advantages of high-throughput screening, accurate control of the fluid velocity, low cell consumption, long-term culture, and high integration. By combining the multipotential differentiation of neural stem cells with high throughput and the integrated characteristics of microfluidic technology, an in vitro model of a functionalized neurovascular unit was established using human neural stem cell-derived neurons, astrocytes, oligodendrocytes, and a functional microvascular barrier. The model comprises a multi-layer vertical neural module and vascular module, both of which were connected with a syringe pump. This provides controllable conditions for cell inoculation and nutrient supply, and simultaneously simulates the process of ischemic/hypoxic injury and the process of inflammatory factors in the circulatory system passing through the blood-brain barrier and then acting on the nerve tissue in the brain. The in vitro functionalized neurovascular unit model will be conducive to central nervous system disease research, drug screening, and new drug development.
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Affiliation(s)
- Wen-Juan Wei
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, the First Affiliated Hospital of Dalian Medical University; Dalian Innovation Institute of Stem Cell and Precision Medicine, Dalian, Liaoning Province, China
| | - Ya-Chen Wang
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, the First Affiliated Hospital of Dalian Medical University; Dalian Innovation Institute of Stem Cell and Precision Medicine, Dalian, Liaoning Province, China
| | - Xin Guan
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, the First Affiliated Hospital of Dalian Medical University; Dalian Innovation Institute of Stem Cell and Precision Medicine, Dalian, Liaoning Province, China
| | - Wei-Gong Chen
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, the First Affiliated Hospital of Dalian Medical University; Dalian Innovation Institute of Stem Cell and Precision Medicine, Dalian, Liaoning Province, China
| | - Jing Liu
- Stem Cell Clinical Research Center, National Joint Engineering Laboratory, Regenerative Medicine Center, the First Affiliated Hospital of Dalian Medical University; Dalian Innovation Institute of Stem Cell and Precision Medicine, Dalian, Liaoning Province, China
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7
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Roy P, Tomassoni D, Nittari G, Traini E, Amenta F. Effects of choline containing phospholipids on the neurovascular unit: A review. Front Cell Neurosci 2022; 16:988759. [PMID: 36212684 PMCID: PMC9541750 DOI: 10.3389/fncel.2022.988759] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
The roles of choline and of choline-containing phospholipids (CCPLs) on the maintenance and progress of neurovascular unit (NVU) integrity are analyzed. NVU is composed of neurons, glial and vascular cells ensuring the correct homeostasis of the blood-brain barrier (BBB) and indirectly the function of the central nervous system. The CCPLs phosphatidylcholine (lecithin), cytidine 5′-diphosphocholine (CDP-choline), choline alphoscerate or α-glyceryl-phosphorylcholine (α-GPC) contribute to the modulation of the physiology of the NVU cells. A loss of CCPLs contributes to the development of neurodegenerative diseases such as Alzheimer’s disease, multiple sclerosis, Parkinson’s disease. Our study has characterized the cellular components of the NVU and has reviewed the effect of lecithin, of CDP-choline and α-GPC documented in preclinical studies and in limited clinical trials on these compounds. The interesting results obtained with some CCPLs, in particular with α-GPC, probably would justify reconsideration of the most promising molecules in larger attentively controlled studies. This can also contribute to better define the role of the NVU in the pathophysiology of brain disorders characterized by vascular impairment.
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Affiliation(s)
- Proshanta Roy
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Daniele Tomassoni
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Giulio Nittari
- School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy
| | - Enea Traini
- School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy
| | - Francesco Amenta
- School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy
- *Correspondence: Francesco Amenta,
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8
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Pintér P, Alpár A. The Role of Extracellular Matrix in Human Neurodegenerative Diseases. Int J Mol Sci 2022; 23:ijms231911085. [PMID: 36232390 PMCID: PMC9569603 DOI: 10.3390/ijms231911085] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/16/2022] [Accepted: 09/19/2022] [Indexed: 11/16/2022] Open
Abstract
The dense neuropil of the central nervous system leaves only limited space for extracellular substances free. The advent of immunohistochemistry, soon followed by advanced diagnostic tools, enabled us to explore the biochemical heterogeneity and compartmentalization of the brain extracellular matrix in exploratory and clinical research alike. The composition of the extracellular matrix is critical to shape neuronal function; changes in its assembly trigger or reflect brain/spinal cord malfunction. In this study, we focus on extracellular matrix changes in neurodegenerative disorders. We summarize its phenotypic appearance and biochemical characteristics, as well as the major enzymes which regulate and remodel matrix establishment in disease. The specifically built basement membrane of the central nervous system, perineuronal nets and perisynaptic axonal coats can protect neurons from toxic agents, and biochemical analysis revealed how the individual glycosaminoglycan and proteoglycan components interact with these molecules. Depending on the site, type and progress of the disease, select matrix components can either proactively trigger the formation of disease-specific harmful products, or reactively accumulate, likely to reduce tissue breakdown and neuronal loss. We review the diagnostic use and the increasing importance of medical screening of extracellular matrix components, especially enzymes, which informs us about disease status and, better yet, allows us to forecast illness.
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Affiliation(s)
- Panka Pintér
- Department of Anatomy, Semmelweis University, 1113 Budapest, Hungary
| | - Alán Alpár
- Department of Anatomy, Semmelweis University, 1113 Budapest, Hungary
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Correspondence:
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9
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Argent LP, Bose A, Paton JFR. Intra-carotid body inter-cellular communication. J R Soc N Z 2022. [DOI: 10.1080/03036758.2022.2079681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Liam P. Argent
- Manaaki Manawa – the Centre for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Aabharika Bose
- Manaaki Manawa – the Centre for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Julian F. R. Paton
- Manaaki Manawa – the Centre for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
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10
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Advances in Hydrogel-Based Microfluidic Blood–Brain-Barrier Models in Oncology Research. Pharmaceutics 2022; 14:pharmaceutics14050993. [PMID: 35631579 PMCID: PMC9144371 DOI: 10.3390/pharmaceutics14050993] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/30/2022] [Accepted: 05/03/2022] [Indexed: 12/10/2022] Open
Abstract
The intrinsic architecture and complexity of the brain restricts the capacity of therapeutic molecules to reach their potential targets, thereby limiting therapeutic possibilities concerning neurological ailments and brain malignancy. As conventional models fail to recapitulate the complexity of the brain, progress in the field of microfluidics has facilitated the development of advanced in vitro platforms that could imitate the in vivo microenvironments and pathological features of the blood–brain barrier (BBB). It is highly desirous that developed in vitro BBB-on-chip models serve as a platform to investigate cancer metastasis of the brain along with the possibility of efficiently screening chemotherapeutic agents against brain malignancies. In order to improve the proficiency of BBB-on-chip models, hydrogels have been widely explored due to their unique physical and chemical properties, which mimic the three-dimensional (3D) micro architecture of tissues. Hydrogel-based BBB-on-chip models serves as a stage which is conducive for cell growth and allows the exchange of gases and nutrients and the removal of metabolic wastes between cells and the cell/extra cellular matrix (ECM) interface. Here, we present recent advancements in BBB-on-chip models targeting brain malignancies and examine the utility of hydrogel-based BBB models that could further strengthen the future application of microfluidic devices in oncology research.
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11
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Piccialli I, Tedeschi V, Caputo L, D’Errico S, Ciccone R, De Feo V, Secondo A, Pannaccione A. Exploring the Therapeutic Potential of Phytochemicals in Alzheimer’s Disease: Focus on Polyphenols and Monoterpenes. Front Pharmacol 2022; 13:876614. [PMID: 35600880 PMCID: PMC9114803 DOI: 10.3389/fphar.2022.876614] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/11/2022] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD) is a chronic, complex neurodegenerative disorder mainly characterized by the irreversible loss of memory and cognitive functions. Different hypotheses have been proposed thus far to explain the etiology of this devastating disorder, including those centered on the Amyloid-β (Aβ) peptide aggregation, Tau hyperphosphorylation, neuroinflammation and oxidative stress. Nonetheless, the therapeutic strategies conceived thus far to treat AD neurodegeneration have proven unsuccessful, probably due to the use of single-target drugs unable to arrest the progressive deterioration of brain functions. For this reason, the theoretical description of the AD etiology has recently switched from over-emphasizing a single deleterious process to considering AD neurodegeneration as the result of different pathogenic mechanisms and their interplay. Moreover, much relevance has recently been conferred to several comorbidities inducing insulin resistance and brain energy hypometabolism, including diabetes and obesity. As consequence, much interest is currently accorded in AD treatment to a multi-target approach interfering with different pathways at the same time, and to life-style interventions aimed at preventing the modifiable risk-factors strictly associated with aging. In this context, phytochemical compounds are emerging as an enormous source to draw on in the search for multi-target agents completing or assisting the traditional pharmacological medicine. Intriguingly, many plant-derived compounds have proven their efficacy in counteracting several pathogenic processes such as the Aβ aggregation, neuroinflammation, oxidative stress and insulin resistance. Many strategies have also been conceived to overcome the limitations of some promising phytochemicals related to their poor pharmacokinetic profiles, including nanotechnology and synthetic routes. Considering the emerging therapeutic potential of natural medicine, the aim of the present review is therefore to highlight the most promising phytochemical compounds belonging to two major classes, polyphenols and monoterpenes, and to report the main findings about their mechanisms of action relating to the AD pathogenesis.
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Affiliation(s)
- Ilaria Piccialli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Valentina Tedeschi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Lucia Caputo
- Department of Pharmacy, University of Salerno, Salerno, Italy
| | - Stefano D’Errico
- Department of Pharmacy, University of Naples “Federico II”, Naples, Italy
| | - Roselia Ciccone
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Vincenzo De Feo
- Department of Pharmacy, University of Salerno, Salerno, Italy
| | - Agnese Secondo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
| | - Anna Pannaccione
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, University of Naples “Federico II”, Naples, Italy
- *Correspondence: Anna Pannaccione,
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12
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Luo C, Zhou S, Yin S, Jian L, Luo P, Dong J, Liu E. Lipocalin-2 and Cerebral Stroke. Front Mol Neurosci 2022; 15:850849. [PMID: 35493318 PMCID: PMC9039332 DOI: 10.3389/fnmol.2022.850849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 02/23/2022] [Indexed: 11/26/2022] Open
Abstract
Stroke is a common and devastating disease with an escalating prevalence worldwide. The known secondary injuries after stroke include cell death, neuroinflammation, blood-brain barrier disruption, oxidative stress, iron dysregulation, and neurovascular unit dysfunction. Lipocalin-2 (LCN-2) is a neutrophil gelatinase-associated protein that influences diverse cellular processes during a stroke. The role of LCN-2 has been widely recognized in the peripheral system; however, recent findings have revealed that there are links between LCN-2 and secondary injury and diseases in the central nervous system. Novel roles of LCN-2 in neurons, microglia, astrocytes, and endothelial cells have also been demonstrated. Here, we review the evidence on the regulatory roles of LCN-2 in secondary injuries following a stroke from various perspectives and the pathological mechanisms involved in the modulation of stroke. Overall, our review suggests that LCN-2 is a promising target to promote a better understanding of the neuropathology of stroke.
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Affiliation(s)
- Chao Luo
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Shuai Zhou
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
- Department of Neurosurgery, The First People’s Hospital of Yunnan Province, Kunming, China
| | - Shi Yin
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Lipeng Jian
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Pengren Luo
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Jigeng Dong
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Erheng Liu
- Department of Neurosurgery, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
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13
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Bai T, Yu S, Feng J. Advances in the Role of Endothelial Cells in Cerebral Small Vessel Disease. Front Neurol 2022; 13:861714. [PMID: 35481273 PMCID: PMC9035937 DOI: 10.3389/fneur.2022.861714] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/09/2022] [Indexed: 12/13/2022] Open
Abstract
Cerebral small vessel disease (CSVD) poses a serious socio-economic burden due to its high prevalence and severe impact on the quality of life of elderly patients. Pathological changes in CSVD mainly influence small cerebral arteries, microarteries, capillaries, and small veins, which are usually caused by multiple vascular risk factors. CSVD is often identified on brain magnetic resonance imaging (MRI) by recent small subcortical infarcts, white matter hyperintensities, lacune, cerebral microbleeds (CMBs), enlarged perivascular spaces (ePVSs), and brain atrophy. Endothelial cell (EC) dysfunction is earlier than clinical symptoms. Immune activation, inflammation, and oxidative stress may be potential mechanisms of EC injury. ECs of the blood–brain–barrier (BBB) are the most important part of the neurovascular unit (NVU) that ensures constant blood flow to the brain. Impaired cerebral vascular autoregulation and disrupted BBB cause cumulative brain damage. This review will focus on the role of EC injury in CSVD. Furthermore, several specific biomarkers will be discussed, which may be useful for us to assess the endothelial dysfunction and explore new therapeutic directions.
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Puebla M, Tapia PJ, Espinoza H. Key Role of Astrocytes in Postnatal Brain and Retinal Angiogenesis. Int J Mol Sci 2022; 23:ijms23052646. [PMID: 35269788 PMCID: PMC8910249 DOI: 10.3390/ijms23052646] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 01/27/2023] Open
Abstract
Angiogenesis is a key process in various physiological and pathological conditions in the nervous system and in the retina during postnatal life. Although an increasing number of studies have addressed the role of endothelial cells in this event, the astrocytes contribution in angiogenesis has received less attention. This review is focused on the role of astrocytes as a scaffold and in the stabilization of the new blood vessels, through different molecules release, which can modulate the angiogenesis process in the brain and in the retina. Further, differences in the astrocytes phenotype are addressed in glioblastoma, one of the most devastating types of brain cancer, in order to provide potential targets involved in the cross signaling between endothelial cells, astrocytes and glioma cells, that mediate tumor progression and pathological angiogenesis. Given the relevance of astrocytes in angiogenesis in physiological and pathological conditions, future studies are required to better understand the interrelation between endothelial and astrocyte signaling pathways during this process.
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Affiliation(s)
- Mariela Puebla
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina-Clínica Alemana, Universidad del Desarrollo, Av. Plaza 680, Las Condes, Santiago 7550000, Chile;
| | - Pablo J. Tapia
- Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Av. Lota 2465, Providencia, Santiago 7500000, Chile;
- Facultad de Medicina Veterinaria y Agronomía, Universidad de las Américas, Av. República 71, Santiago 8320000, Chile
| | - Hilda Espinoza
- Facultad de Ciencias de la Salud, Universidad del Alba, Av. Ejército Libertador 171, Santiago 8320000, Chile
- Correspondence:
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15
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Yuan M, Wang Y, Wang S, Huang Z, Jin F, Zou Q, Li J, Pu Y, Cai Z. Bioenergetic Impairment in the Neuro-Glia-Vascular Unit: An Emerging Physiopathology during Aging. Aging Dis 2021; 12:2080-2095. [PMID: 34881087 PMCID: PMC8612602 DOI: 10.14336/ad.2021.04017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 04/17/2021] [Indexed: 12/28/2022] Open
Abstract
An emerging concept termed the "neuro-glia-vascular unit" (NGVU) has been established in recent years to understand the complicated mechanism of multicellular interactions among vascular cells, glial cells, and neurons. It has been proverbially reported that the NGVU is significantly associated with neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). Physiological aging is an inevitable progression associated with oxidative damage, bioenergetic alterations, mitochondrial dysfunction, and neuroinflammation, which is partially similar to the pathology of AD. Thus, senescence is regarded as the background for the development of neurodegenerative diseases. With the exacerbation of global aging, senescence is an increasingly serious problem in the medical field. In this review, the coupling of each component, including neurons, glial cells, and vascular cells, in the NGVU is described in detail. Then, various mechanisms of age-dependent impairment in each part of the NGVU are discussed. Moreover, the potential bioenergetic alterations between different cell types in the NGVU are highlighted, which seems to be an emerging physiopathology associated with the aged brain. Bioenergetic intervention in the NGVU may be a new direction for studies on delaying or diminishing aging in the future.
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Affiliation(s)
- Minghao Yuan
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,2Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China.,4Chongqing Medical University, Chongqing, China
| | - Yangyang Wang
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China
| | - Shengyuan Wang
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,2Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China.,4Chongqing Medical University, Chongqing, China
| | - Zhenting Huang
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China
| | - Feng Jin
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,2Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China
| | - Qian Zou
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China
| | - Jing Li
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China
| | - Yinshuang Pu
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China
| | - Zhiyou Cai
- 1Department of Neurology, Chongqing General Hospital, University of Chinese Academy of Sciences, Chongqing, 400013, Chongqing, China.,2Chongqing School, University of Chinese Academy of Sciences, Chongqing, China.,3Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing, 400013, Chongqing, China.,4Chongqing Medical University, Chongqing, China
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16
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Rinaldi C, Donato L, Alibrandi S, Scimone C, D’Angelo R, Sidoti A. Oxidative Stress and the Neurovascular Unit. Life (Basel) 2021; 11:life11080767. [PMID: 34440511 PMCID: PMC8398978 DOI: 10.3390/life11080767] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/15/2022] Open
Abstract
The neurovascular unit (NVU) is a relatively recent concept that clearly describes the relationship between brain cells and their blood vessels. The components of the NVU, comprising different types of cells, are so interrelated and associated with each other that they are considered as a single functioning unit. For this reason, even slight disturbances in the NVU could severely affect brain homeostasis and health. In this review, we aim to describe the current state of knowledge concerning the role of oxidative stress on the neurovascular unit and the role of a single cell type in the NVU crosstalk.
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Affiliation(s)
- Carmela Rinaldi
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
| | - Luigi Donato
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics and Avant-Garde Therapies, Istituto Euro-Mediterraneo di Scienza e Tecnologia (I.E.ME.S.T.), Via Michele Miraglia, 90139 Palermo, Italy
| | - Simona Alibrandi
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 Messina, Italy
| | - Concetta Scimone
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
- Department of Biomolecular Strategies, Genetics and Avant-Garde Therapies, Istituto Euro-Mediterraneo di Scienza e Tecnologia (I.E.ME.S.T.), Via Michele Miraglia, 90139 Palermo, Italy
- Correspondence:
| | - Rosalia D’Angelo
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
| | - Antonina Sidoti
- Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (C.R.); (L.D.); (S.A.); (R.D.); (A.S.)
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17
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Paquette T, Piché M, Leblond H. Contribution of astrocytes to neurovascular coupling in the spinal cord of the rat. J Physiol Sci 2021; 71:16. [PMID: 34049480 PMCID: PMC10717833 DOI: 10.1186/s12576-021-00800-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/19/2021] [Indexed: 12/13/2022]
Abstract
Functional magnetic resonance imaging (fMRI) of the spinal cord relies on the integrity of neurovascular coupling (NVC) to infer neuronal activity from hemodynamic changes. Astrocytes are a key component of cerebral NVC, but their role in spinal NVC is unclear. The objective of this study was to examine whether inhibition of astrocyte metabolism by fluorocitrate alters spinal NVC. In 14 rats, local field potential (LFP) and spinal cord blood flow (SCBF) were recorded simultaneously in the lumbosacral enlargement during noxious stimulation of the sciatic nerve before and after a local administration of fluorocitrate (N = 7) or saline (N = 7). Fluorocitrate significantly reduced SCBF responses (p < 0.001) but not LFP amplitude (p = 0.22) compared with saline. Accordingly, NVC was altered by fluorocitrate compared with saline (p < 0.01). These results support the role of astrocytes in spinal NVC and have implications for spinal cord imaging with fMRI for conditions in which astrocyte metabolism may be altered.
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Affiliation(s)
- Thierry Paquette
- Department of Anatomy, Université du Québec À Trois-Rivières, 3351 Boulevard des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada
- CogNAC Research Group, Université du Québec À Trois-Rivières, Trois-Rivières, QC, G9A 5H7, Canada
| | - Mathieu Piché
- Department of Anatomy, Université du Québec À Trois-Rivières, 3351 Boulevard des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada
- CogNAC Research Group, Université du Québec À Trois-Rivières, Trois-Rivières, QC, G9A 5H7, Canada
| | - Hugues Leblond
- Department of Anatomy, Université du Québec À Trois-Rivières, 3351 Boulevard des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.
- CogNAC Research Group, Université du Québec À Trois-Rivières, Trois-Rivières, QC, G9A 5H7, Canada.
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18
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Olung NF, Aluko OM, Jeje SO, Adeagbo AS, Ijomone OM. Vascular Dysfunction in the Brain; Implications for Heavy Metal Exposures. Curr Hypertens Rev 2021; 17:5-13. [PMID: 33632106 DOI: 10.2174/1573402117666210225085528] [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: 07/13/2020] [Revised: 10/24/2020] [Accepted: 12/01/2020] [Indexed: 11/22/2022]
Abstract
Normal or diseased conditions that alter the brain's requirement for oxygen and nutrients via alterations to neurovascular coupling have an impact on the level of the neurovascular unit; comprising neuronal, glial and vascular components. The communications between the components of the neurovascular unit are precise and accurate for its functions; hence a minute disturbance can result in neurovascular dysfunction. Heavy metals such as cadmium, mercury, and lead have been identified to increase the vulnerability of the neurovascular unit to damage. This review examines the role of heavy metals in neurovascular dysfunctions and the possible mechanisms by which these metals act. Risk factors ranging from lifestyle, environment, genetics, infections, and physiologic ageing involved in neurological dysfunctions were highlighted, while stroke was discussed as the prevalent consequence of neurovascular dysfunctions. Furthermore, the role of these heavy metals in the pathogenesis of stroke consequently pinpoints the importance of understanding the mechanisms of neurovascular damage in a bid to curb the occurrence of neurovascular dysfunctions.
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Affiliation(s)
- Nzube F Olung
- The Neuro-Lab, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Oritoke M Aluko
- The Neuro-Lab, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Sikirullai O Jeje
- Department of Physiology, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Ayotunde S Adeagbo
- Department of Physiology, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
| | - Omamuyovwi M Ijomone
- The Neuro-Lab, School of Health and Health Technology, Federal University of Technology, Akure, Nigeria
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19
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Sun Q, Xu X, Wang T, Xu Z, Lu X, Li X, Chen G. Neurovascular Units and Neural-Glia Networks in Intracerebral Hemorrhage: from Mechanisms to Translation. Transl Stroke Res 2021; 12:447-460. [PMID: 33629275 DOI: 10.1007/s12975-021-00897-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 12/20/2022]
Abstract
Intracerebral hemorrhage (ICH), the most lethal type of stroke, often leads to poor outcomes in the clinic. Due to the complex mechanisms and cell-cell crosstalk during ICH, the neurovascular unit (NVU) was proposed to serve as a promising therapeutic target for ICH research. This review aims to summarize the development of pathophysiological shifts in the NVU and neural-glia networks after ICH. In addition, potential targets for ICH therapy are discussed in this review. Beyond cerebral blood flow, the NVU also plays an important role in protecting neurons, maintaining central nervous system (CNS) homeostasis, coordinating neuronal activity among supporting cells, forming and maintaining the blood-brain barrier (BBB), and regulating neuroimmune responses. During ICH, NVU dysfunction is induced, along with neuronal cell death, microglia and astrocyte activation, endothelial cell (EC) and tight junction (TJ) protein damage, and BBB disruption. In addition, it has been shown that certain targets and candidates can improve ICH-induced secondary brain injury based on an NVU and neural-glia framework. Moreover, therapeutic approaches and strategies for ICH are discussed.
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Affiliation(s)
- Qing Sun
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Xiang Xu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Tianyi Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Zhongmou Xu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Xiaocheng Lu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
| | - Xiang Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
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20
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The Neurovascular Unit Dysfunction in Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms22042022. [PMID: 33670754 PMCID: PMC7922832 DOI: 10.3390/ijms22042022] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/06/2021] [Accepted: 01/11/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease worldwide. Histopathologically, AD presents with two hallmarks: neurofibrillary tangles (NFTs), and aggregates of amyloid β peptide (Aβ) both in the brain parenchyma as neuritic plaques, and around blood vessels as cerebral amyloid angiopathy (CAA). According to the vascular hypothesis of AD, vascular risk factors can result in dysregulation of the neurovascular unit (NVU) and hypoxia. Hypoxia may reduce Aβ clearance from the brain and increase its production, leading to both parenchymal and vascular accumulation of Aβ. An increase in Aβ amplifies neuronal dysfunction, NFT formation, and accelerates neurodegeneration, resulting in dementia. In recent decades, therapeutic approaches have attempted to decrease the levels of abnormal Aβ or tau levels in the AD brain. However, several of these approaches have either been associated with an inappropriate immune response triggering inflammation, or have failed to improve cognition. Here, we review the pathogenesis and potential therapeutic targets associated with dysfunction of the NVU in AD.
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21
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Solovyev N, Drobyshev E, Blume B, Michalke B. Selenium at the Neural Barriers: A Review. Front Neurosci 2021; 15:630016. [PMID: 33613188 PMCID: PMC7892976 DOI: 10.3389/fnins.2021.630016] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022] Open
Abstract
Selenium (Se) is known to contribute to several vital physiological functions in mammals: antioxidant defense, fertility, thyroid hormone metabolism, and immune response. Growing evidence indicates the crucial role of Se and Se-containing selenoproteins in the brain and brain function. As for the other essential trace elements, dietary Se needs to reach effective concentrations in the central nervous system (CNS) to exert its functions. To do so, Se-species have to cross the blood-brain barrier (BBB) and/or blood-cerebrospinal fluid barrier (BCB) of the choroid plexus. The main interface between the general circulation of the body and the CNS is the BBB. Endothelial cells of brain capillaries forming the so-called tight junctions are the primary anatomic units of the BBB, mainly responsible for barrier function. The current review focuses on Se transport to the brain, primarily including selenoprotein P/low-density lipoprotein receptor-related protein 8 (LRP8, also known as apolipoprotein E receptor-2) dependent pathway, and supplementary transport routes of Se into the brain via low molecular weight Se-species. Additionally, the potential role of Se and selenoproteins in the BBB, BCB, and neurovascular unit (NVU) is discussed. Finally, the perspectives regarding investigating the role of Se and selenoproteins in the gut-brain axis are outlined.
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Affiliation(s)
| | - Evgenii Drobyshev
- Institut für Ernährungswissenschaft, Universität Potsdam, Potsdam, Germany
| | - Bastian Blume
- Research Unit Analytical BioGeoChemistry, Helmholtz Center Munich – German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Bernhard Michalke
- Research Unit Analytical BioGeoChemistry, Helmholtz Center Munich – German Research Center for Environmental Health (GmbH), Neuherberg, Germany
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22
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Clé M, Constant O, Barthelemy J, Desmetz C, Martin MF, Lapeyre L, Cadar D, Savini G, Teodori L, Monaco F, Schmidt-Chanasit J, Saiz JC, Gonzales G, Lecollinet S, Beck C, Gosselet F, Van de Perre P, Foulongne V, Salinas S, Simonin Y. Differential neurovirulence of Usutu virus lineages in mice and neuronal cells. J Neuroinflammation 2021; 18:11. [PMID: 33407600 PMCID: PMC7789689 DOI: 10.1186/s12974-020-02060-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/11/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Usutu virus (USUV) is an emerging neurotropic arthropod-borne virus recently involved in massive die offs of wild birds predominantly reported in Europe. Although primarily asymptomatic or presenting mild clinical signs, humans infected by USUV can develop neuroinvasive pathologies (including encephalitis and meningoencephalitis). Similar to other flaviviruses, such as West Nile virus, USUV is capable of reaching the central nervous system. However, the neuropathogenesis of USUV is still poorly understood, and the virulence of the specific USUV lineages is currently unknown. One of the major complexities of the study of USUV pathogenesis is the presence of a great diversity of lineages circulating at the same time and in the same location. METHODS The aim of this work was to determine the neurovirulence of isolates from the six main lineages circulating in Europe using mouse model and several neuronal cell lines (neurons, microglia, pericytes, brain endothelial cells, astrocytes, and in vitro Blood-Brain Barrier model). RESULTS Our results indicate that all strains are neurotropic but have different virulence profiles. The Europe 2 strain, previously described as being involved in several clinical cases, induced the shortest survival time and highest mortality in vivo and appeared to be more virulent and persistent in microglial, astrocytes, and brain endothelial cells, while also inducing an atypical cytopathic effect. Moreover, an amino acid substitution (D3425E) was specifically identified in the RNA-dependent RNA polymerase domain of the NS5 protein of this lineage. CONCLUSIONS Altogether, these data show a broad neurotropism for USUV in the central nervous system with lineage-dependent virulence. Our results will help to better understand the biological and epidemiological diversity of USUV infection.
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Affiliation(s)
- Marion Clé
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France
| | - Orianne Constant
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France
| | - Jonathan Barthelemy
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France
| | - Caroline Desmetz
- BioCommunication en CardioMétabolique (BC2M), Montpellier University, Montpellier, France
| | - Marie France Martin
- Université de Montpellier, CNRS, Viral Trafficking, Restriction and Innate Signaling, Montpellier, France
| | - Lina Lapeyre
- Université de Montpellier, CNRS, Viral Trafficking, Restriction and Innate Signaling, Montpellier, France
| | - Daniel Cadar
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, 20359, Hamburg, Germany
| | - Giovanni Savini
- OIE Reference Centre for West Nile Disease, Istituto Zooprofilattico Sperimentale "G. Caporale", 46100, Teramo, Italy
| | - Liana Teodori
- OIE Reference Centre for West Nile Disease, Istituto Zooprofilattico Sperimentale "G. Caporale", 46100, Teramo, Italy
| | - Federica Monaco
- OIE Reference Centre for West Nile Disease, Istituto Zooprofilattico Sperimentale "G. Caporale", 46100, Teramo, Italy
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, 20359, Hamburg, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, 20148, Hamburg, Germany
| | | | - Gaëlle Gonzales
- UPE, Anses Animal Health Laboratory, UMR1161 Virology, INRA, Anses, ENVA, Maisons-Alfort, France
| | - Sylvie Lecollinet
- UPE, Anses Animal Health Laboratory, UMR1161 Virology, INRA, Anses, ENVA, Maisons-Alfort, France
| | - Cécile Beck
- UPE, Anses Animal Health Laboratory, UMR1161 Virology, INRA, Anses, ENVA, Maisons-Alfort, France
| | - Fabien Gosselet
- Blood-Brain Barrier Laboratory (BBB Lab), University of Artois, UR2465, F-62300, Lens, France
| | - Philippe Van de Perre
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France
- Centre Hospitalier Universitaire de Montpellier, Montpellier, France
| | - Vincent Foulongne
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France
- Centre Hospitalier Universitaire de Montpellier, Montpellier, France
| | - Sara Salinas
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France
| | - Yannick Simonin
- Pathogenesis and Control of Chronic Infections, Université de Montpellier, INSERM, EFS, Montpellier, France.
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23
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Tice C, McDevitt J, Langford D. Astrocytes, HIV and the Glymphatic System: A Disease of Disrupted Waste Management? Front Cell Infect Microbiol 2020; 10:523379. [PMID: 33134185 PMCID: PMC7550659 DOI: 10.3389/fcimb.2020.523379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 08/19/2020] [Indexed: 12/17/2022] Open
Abstract
The discovery of the glial-lymphatic or glymphatic fluid clearance pathway in the rodent brain led researchers to search for a parallel system in humans and to question the implications of this pathway in neurodegenerative diseases. Magnetic resonance imaging studies revealed that several features of the glymphatic system may be present in humans. In both rodents and humans, this pathway promotes the exchange of interstitial fluid (ISF) and cerebrospinal fluid (CSF) through the arterial perivascular spaces into the brain parenchyma. This process is facilitated in part by aquaporin-4 (AQP4) water channels located primarily on astrocytic end feet that abut cerebral endothelial cells of the blood brain barrier. Decreased expression or mislocalization of AQP4 from astrocytic end feet results in decreased interstitial flow, thereby, promoting accumulation of extracellular waste products like hyperphosphorylated Tau (pTau). Accumulation of pTau is a neuropathological hallmark in Alzheimer's disease (AD) and is accompanied by mislocalization of APQ4 from astrocyte end feet to the cell body. HIV infection shares many neuropathological characteristics with AD. Similar to AD, HIV infection of the CNS contributes to abnormal aging with altered AQP4 localization, accumulation of pTau and chronic neuroinflammation. Up to 30% of people with HIV (PWH) suffer from HIV-associated neurocognitive disorders (HAND), and changes in AQP4 may be clinically important as a contributor to cognitive disturbances. In this review, we provide an overview and discussion of the potential contributions of NeuroHIV to glymphatic system functions by focusing on astrocytes and AQP4. Although HAND encompasses a wide range of neurocognitive impairments and levels of neuroinflammation vary among and within PWH, the potential contribution of disruption in AQP4 may be clinically important in some cases. In this review we discuss implications for possible AQP4 disruption on NeuroHIV disease trajectory and how HIV may influence AQP4 function.
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Affiliation(s)
- Caitlin Tice
- Department of Neuroscience, Lewis Katz School of Medicine, Philadelphia, PA, United States
| | - Jane McDevitt
- Department of Kinesiology, College of Public Health at Temple University, Philadelphia, PA, United States
| | - Dianne Langford
- Department of Neuroscience, Lewis Katz School of Medicine, Philadelphia, PA, United States
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Abstract
PURPOSE To review the recent developments on the effect of chronic high mean arterial blood pressure (MAP) on cerebral blood flow (CBF) autoregulation and supporting the notion that CBF autoregulation impairment has connection with chronic cerebral diseases. Method: A narrative review of all the relevant papers known to the authors was conducted. Results: Our understanding of the connection between cerebral perfusion impairment and chronic high MAP and cerebral disease is rapidly evolving, from cerebral perfusion impairment being the result of cerebral diseases to being the cause of cerebral diseases. We now better understand the intertwined impact of hypertension and Alzheimer's disease (AD) on cerebrovascular sensory elements and recognize cerebrovascular elements that are more vulnerable to these diseases. Conclusion: We conclude with the suggestion that the sensory elements pathology plays important roles in intertwined mechanisms of chronic high MAP and AD that impact cerebral perfusion.
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Affiliation(s)
- Noushin Yazdani
- College of Public Health, University of South Florida , Tampa, FL, USA
| | - Mark S Kindy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Biomedical Research, James A. Haley VA Medical Center , Tampa, FL, USA
| | - Saeid Taheri
- Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida , Tampa, FL, USA.,Byrd Neuroscience Institute, University of South Florida , Tampa, FL, USA
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25
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Ogaki A, Ikegaya Y, Koyama R. Vascular Abnormalities and the Role of Vascular Endothelial Growth Factor in the Epileptic Brain. Front Pharmacol 2020; 11:20. [PMID: 32116699 PMCID: PMC7010950 DOI: 10.3389/fphar.2020.00020] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 01/08/2020] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is a chronic neurological disorder generally defined to be caused by excessive neuronal activity. Thus, excessive neuronal activity is the main target of the currently used antiepileptic drugs (AEDs). However, as many as 30% of epileptic patients show drug resistance to currently available AEDs, which suggests that epilepsy should be attributed not only to neuronal cells but also to other brain cells, such as glial cells and vascular cells. Astrocytes, pericytes, and endothelial cells in particular comprise the blood–brain barrier (BBB), which tightly regulates the exchange of substances between the brain parenchyma and the circulating blood. It has been proposed that BBB dysfunction, especially barrier leakage, exacerbates epileptic progression, and conversely, that epileptic seizures induce barrier leakage. Furthermore, several studies have shown that BBB dysfunction is one of the main causes of drug resistance in epilepsy. To better understand the mechanisms that link BBB dysfunction and intractable epilepsy to gain insights for the future development of treatments, we review and discuss the relationships between epilepsy and brain vascular abnormalities, mainly by focusing on vascular malformation, BBB dysfunction, and excessive angiogenesis. Because these abnormalities have been reported to be caused by vascular endothelial growth factor (VEGF) in the ischemic brain, we discuss the possible role of VEGF in vascular abnormalities in the epileptic brain, in which the upregulation of VEGF levels has been reported. Both glial cells and endothelial cells express VEGF receptors (VEGFRs); thus, these cells are likely affected by increases in VEGF during seizures, which in turn could cause vascular abnormalities. In this review, we review the possible role of VEGF in epilepsy and discuss the mechanisms that link vascular abnormalities and intractable epilepsy.
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Affiliation(s)
- Ari Ogaki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Japan.,Center for Information and Neural Networks, National Institute of Information and Communications and Technology, Suita City, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Japan
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26
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Netto JP, Iliff J, Stanimirovic D, Krohn KA, Hamilton B, Varallyay C, Gahramanov S, Daldrup-Link H, d'Esterre C, Zlokovic B, Sair H, Lee Y, Taheri S, Jain R, Panigrahy A, Reich DS, Drewes LR, Castillo M, Neuwelt EA. Neurovascular Unit: Basic and Clinical Imaging with Emphasis on Advantages of Ferumoxytol. Neurosurgery 2019; 82:770-780. [PMID: 28973554 DOI: 10.1093/neuros/nyx357] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 06/27/2017] [Indexed: 12/11/2022] Open
Abstract
Physiological and pathological processes that increase or decrease the central nervous system's need for nutrients and oxygen via changes in local blood supply act primarily at the level of the neurovascular unit (NVU). The NVU consists of endothelial cells, associated blood-brain barrier tight junctions, basal lamina, pericytes, and parenchymal cells, including astrocytes, neurons, and interneurons. Knowledge of the NVU is essential for interpretation of central nervous system physiology and pathology as revealed by conventional and advanced imaging techniques. This article reviews current strategies for interrogating the NVU, focusing on vascular permeability, blood volume, and functional imaging, as assessed by ferumoxytol an iron oxide nanoparticle.
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Affiliation(s)
- Joao Prola Netto
- Department of Neurology, Oregon Health & Science University, Portland, Oregon.,Department of Neuroradiology, Oregon Health & Science University, Portland, Oregon
| | - Jeffrey Iliff
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon
| | - Danica Stanimirovic
- Human Health Therapeutics Portfolio, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Kenneth A Krohn
- Department of Radiology, University of Washington, Seattle, Washington.,Department of Radiology, Oregon Health & Science University, Portland, Oregon
| | - Bronwyn Hamilton
- Department of Neuroradiology, Oregon Health & Science University, Portland, Oregon
| | - Csanad Varallyay
- Department of Neurology, Oregon Health & Science University, Portland, Oregon.,Department of Radiology, Oregon Health & Science University, Portland, Oregon
| | - Seymur Gahramanov
- Department of Neurosurgery, University of New Mexico, Albuquerque, New Mexico
| | | | - Christopher d'Esterre
- Department of Radiology, University of Calgary, Foothills Medical Center, Calgary, Alberta, Canada
| | - Berislav Zlokovic
- Zikha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Haris Sair
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland
| | - Yueh Lee
- Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Saeid Taheri
- Department of Radiology and Radiological Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Rajan Jain
- Department of Radiology and Neurosurgery, New York University School of Medicine, New York, New York
| | - Ashok Panigrahy
- Department of Radiology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Daniel S Reich
- Translational Neuroradiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Lester R Drewes
- Department of Biomedical Sciences, University of Minnesota, Duluth, Minnesota
| | - Mauricio Castillo
- Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Edward A Neuwelt
- Department of Neurology, Oregon Health & Science University, Portland, Oregon.,Department of Neurosurgery, Oregon Health & Science University, Portland, Oregon.,Portland Veterans Affairs Medical Center, Portland, Oregon
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27
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Fingolimod Suppresses the Proinflammatory Status of Interferon-γ-Activated Cultured Rat Astrocytes. Mol Neurobiol 2019; 56:5971-5986. [PMID: 30701416 DOI: 10.1007/s12035-019-1481-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/10/2019] [Indexed: 12/14/2022]
Abstract
Astroglia, the primary homeostatic cells of the central nervous system, play an important role in neuroinflammation. They act as facultative immunocompetent antigen-presenting cells (APCs), expressing major histocompatibility complex (MHC) class II antigens upon activation with interferon (IFN)-γ and possibly other proinflammatory cytokines that are upregulated in disease states, including multiple sclerosis (MS). We characterized the anti-inflammatory effects of fingolimod (FTY720), an established drug for MS, and its phosphorylated metabolite (FTY720-P) in IFN-γ-activated cultured rat astrocytes. The expression of MHC class II compartments, β2 adrenergic receptor (ADR-β2), and nuclear factor kappa-light-chain enhancer of activated B cells subunit p65 (NF-κB p65) was quantified in immunofluorescence images acquired by laser scanning confocal microscopy. In addition, MHC class II-enriched endocytotic vesicles were labeled by fluorescent dextran and their mobility analyzed in astrocytes subjected to different treatments. FTY720 and FTY720-P treatment significantly reduced the number of IFN-γ-induced MHC class II compartments and substantially increased ADR-β2 expression, which is otherwise small or absent in astrocytes in MS. These effects could be partially attributed to the observed decrease in NF-κB p65 expression, because the NF-κB signaling cascade is activated in inflammatory processes. We also found attenuated trafficking and secretion from dextran-labeled endo-/lysosomes that may hinder efficient delivery of MHC class II molecules to the plasma membrane. Our data suggest that FTY720 and FTY720-P at submicromolar concentrations mediate anti-inflammatory effects on astrocytes by suppressing their action as APCs, which may further downregulate the inflammatory process in the brain, constituting the therapeutic effect of fingolimod in MS.
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28
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Du J, Zhang C, Na X, Li A, Zhang Q, Li K, Ding Y. Andrographolide protects mouse astrocytes against hypoxia injury by promoting autophagy and S100B expression. ACTA ACUST UNITED AC 2018; 51:e7061. [PMID: 29694508 PMCID: PMC5937729 DOI: 10.1590/1414-431x20177061] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 12/21/2017] [Indexed: 11/21/2022]
Abstract
Andrographolide (ANDRO) has been studied for its immunomodulation, anti-inflammatory, and neuroprotection effects. Because brain hypoxia is the most common factor of secondary brain injury after traumatic brain injury, we studied the role and possible mechanism of ANDRO in this process using hypoxia-injured astrocytes. Mouse cortical astrocytes C8-D1A (astrocyte type I clone from C57/BL6 strains) were subjected to 3 and 21% of O2 for various times (0–12 h) to establish an astrocyte hypoxia injury model in vitro. After hypoxia and ANDRO administration, the changes in cell viability and apoptosis were assessed using CCK-8 and flow cytometry. Expression changes in apoptosis-related proteins, autophagy-related proteins, main factors of JNK pathway, ATG5, and S100B were determined by western blot. Hypoxia remarkably damaged C8-D1A cells evidenced by reduction of cell viability and induction of apoptosis. Hypoxia also induced autophagy and overproduction of S100B. ANDRO reduced cell apoptosis and promoted cell autophagy and S100B expression. After ANDRO administration, autophagy-related proteins, S-100B, JNK pathway proteins, and ATG5 were all upregulated, while autophagy-related proteins and s100b were downregulated when the jnk pathway was inhibited or ATG5 was knocked down. ANDRO conferred a survival advantage to hypoxia-injured astrocytes by reducing cell apoptosis and promoting autophagy and s100b expression. Furthermore, the promotion of autophagy and s100b expression by ANDRO was via activation of jnk pathway and regulation of ATG5.
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Affiliation(s)
- Juan Du
- Department of Anesthesiology, Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Chunyan Zhang
- Department of Anesthesiology, Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Xueqing Na
- Department of Anesthesiology, Hospital of Kunming Medical University, Kunming, China
| | - Aizhi Li
- Department of Anesthesiology, Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Qingfeng Zhang
- Department of Anesthesiology, Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Kezhong Li
- Department of Anesthesiology, Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Yongbo Ding
- Department of Anesthesiology, Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
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29
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Lee S, Esworthy T, Stake S, Miao S, Zuo YY, Harris BT, Zhang LG. Advances in 3D Bioprinting for Neural Tissue Engineering. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201700213] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Se‐Jun Lee
- Department of Mechanical and Aerospace Engineering George Washington University Washington DC 20052 USA
| | - Timothy Esworthy
- Department of Mechanical and Aerospace Engineering George Washington University Washington DC 20052 USA
| | - Seth Stake
- Department of Medicine George Washington University Washington DC 20052 USA
| | - Shida Miao
- Department of Mechanical and Aerospace Engineering George Washington University Washington DC 20052 USA
| | - Yi Y. Zuo
- Department of Mechanical Engineering University of Hawaii at Manoa Honolulu HI 96822 USA
| | - Brent T. Harris
- Department of Neurology and Pathology Georgetown University Washington DC 20007 USA
| | - Lijie Grace Zhang
- Department of Mechanical and Aerospace Engineering George Washington University Washington DC 20052 USA
- Department of Medicine George Washington University Washington DC 20052 USA
- Department of Biomedical Engineering George Washington University Washington DC 20052 USA
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30
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Prager O, Friedman A, Nebenzahl YM. Role of neural barriers in the pathogenesis and outcome of Streptococcus pneumoniae meningitis. Exp Ther Med 2017; 13:799-809. [PMID: 28450902 PMCID: PMC5403536 DOI: 10.3892/etm.2017.4082] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/10/2016] [Indexed: 12/20/2022] Open
Abstract
Bacterial meningitis is an inflammatory disease of the meninges of the central nervous system (CNS). Streptococcus pneumoniae (S. pneumoniae), Neisseria meningitidis, and Haemophilus influenzae are the major bacterial pathogens causing meningitis with S. pneumoniae being responsible for two thirds of meningitis cases in the developed world. To reach the CNS following nasopharyngeal colonization and bacteraemia, the bacteria traverse from the circulation across the blood brain barrier (BBB) and choroid plexus. While the BBB has a protective role in healthy individuals by shielding the CNS from neurotoxic substances circulating in the blood and maintaining the homeostasis within the brain environment, dysfunction of the BBB is associated with the pathophysiology of numerous neurologic disorders, including bacterial meningitis. Inflammatory processes, including release of a broad range of cytokines and free radicals, further increase vascular permeability and contribute to the excessive neural damage observed. Injury to the cerebral microvasculature and loss of blood flow auto-regulation promote increased intracranial pressure and may lead to vascular occlusion. Other common complications commonly associated with meningitis include abnormal neuronal hyper-excitability (e.g., seizures) and loss of hearing. Despite the existence of antibiotic treatment and adjuvant therapy, the relatively high mortality rate and the severe outcomes among survivors of pneumococcal meningitis in developing and developed countries increase the urgency in the requirement of discovering novel biomarkers for the early diagnosis as well as novel treatment approaches. The present review aimed to explore the changes in the brain vascular barriers, which allow S. pneumoniae to invade the CNS, and describe the resultant brain injuries following bacterial meningitis.
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Affiliation(s)
- Ofer Prager
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of The Negev, Beer-Sheva 84101, Israel.,Cognitive & Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of The Negev, Beer-Sheva 84105, Israel
| | - Alon Friedman
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of The Negev, Beer-Sheva 84101, Israel.,Cognitive & Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of The Negev, Beer-Sheva 84105, Israel.,Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Yaffa Mizrachi Nebenzahl
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of The Negev, Beer-Sheva 84101, Israel
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31
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Ghosh C, Hossain M, Solanki J, Dadas A, Marchi N, Janigro D. Pathophysiological implications of neurovascular P450 in brain disorders. Drug Discov Today 2016; 21:1609-1619. [PMID: 27312874 DOI: 10.1016/j.drudis.2016.06.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/14/2016] [Accepted: 06/06/2016] [Indexed: 01/12/2023]
Abstract
Over the past decades, the significance of cytochrome P450 (CYP) enzymes has expanded beyond their role as peripheral drug metabolizers in the liver and gut. CYP enzymes are also functionally active at the neurovascular interface. CYP expression is modulated by disease states, impacting cellular functions, detoxification, and reactivity to toxic stimuli and brain drug biotransformation. Unveiling the physiological and molecular complexity of brain P450 enzymes will improve our understanding of the mechanisms underlying brain drug availability, pharmacological efficacy, and neurotoxic adverse effects from pharmacotherapy targeting brain disorders.
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Affiliation(s)
- Chaitali Ghosh
- Cerebrovascular Research, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.
| | - Mohammed Hossain
- Cerebrovascular Research, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
| | | | - Aaron Dadas
- The Ohio State University, Columbus, OH, USA
| | - Nicola Marchi
- Cerebrovascular Mechanisms of Brain Disorders, Department of Neuroscience, Institute of Functional Genomics (CNRS/INSERM), Montpellier, France
| | - Damir Janigro
- Flocel Inc. and Case Western Reserve University, Cleveland, OH, USA
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32
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Filosa JA, Morrison HW, Iddings JA, Du W, Kim KJ. Beyond neurovascular coupling, role of astrocytes in the regulation of vascular tone. Neuroscience 2016; 323:96-109. [PMID: 25843438 PMCID: PMC4592693 DOI: 10.1016/j.neuroscience.2015.03.064] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/24/2015] [Accepted: 03/27/2015] [Indexed: 12/22/2022]
Abstract
The brain possesses two intricate mechanisms that fulfill its continuous metabolic needs: cerebral autoregulation, which ensures constant cerebral blood flow over a wide range of arterial pressures and functional hyperemia, which ensures rapid delivery of oxygen and glucose to active neurons. Over the past decade, a number of important studies have identified astrocytes as key intermediaries in neurovascular coupling (NVC), the mechanism by which active neurons signal blood vessels to change their diameter. Activity-dependent increases in astrocytic Ca(2+) activity are thought to contribute to the release of vasoactive substances that facilitate arteriole vasodilation. A number of vasoactive signals have been identified and their role on vessel caliber assessed both in vitro and in vivo. In this review, we discuss mechanisms implicating astrocytes in NVC-mediated vascular responses, limitations encountered as a result of the challenges in maintaining all the constituents of the neurovascular unit intact and deliberate current controversial findings disputing a main role for astrocytes in NVC. Finally, we briefly discuss the potential role of pericytes and microglia in NVC-mediated processes.
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Affiliation(s)
- J A Filosa
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States.
| | - H W Morrison
- University of Arizona, 1305 N. Martin Avenue, P.O. Box 210203, Tucson, AZ 85721, United States
| | - J A Iddings
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
| | - W Du
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
| | - K J Kim
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
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33
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Gebremedhin D, Zhang DX, Carver KA, Rau N, Rarick KR, Roman RJ, Harder DR. Expression of CYP 4A ω-hydroxylase and formation of 20-hydroxyeicosatetreanoic acid (20-HETE) in cultured rat brain astrocytes. Prostaglandins Other Lipid Mediat 2016; 124:16-26. [PMID: 27174801 DOI: 10.1016/j.prostaglandins.2016.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 04/19/2016] [Accepted: 04/27/2016] [Indexed: 02/07/2023]
Abstract
Astrocytes secrete vasodilator and vasoconstrictor factors via end feet processes, altering blood flow to meet neuronal metabolic demand. Compared to what is known about the ability of astrocytes to release factors that dilate local cerebral vasculature, very little is known regarding the source and identity of astrocyte derived constricting factors. The present study investigated if astrocytes express CYP 4A ω-hydroxylase and metabolize arachidonic acid (AA) to 20-hydroxyeicotetraenoic acid (20-HETE) that regulates KCa channel activity in astrocytes and cerebral arterial myocyte contractility. Here we report that cultured astrocytes express CYP 4A2/3 ω-hydroxylase mRNA and CYP 4A protein and produce 20-HETE and the CYP epoxygenase metabolites epoxyeicosatrienoic acids (EETs) when incubated with AA. The production of 20-HETE and EETs was enhanced following stimulation of metabotropic glutamate receptors (mGluR) on the astrocytes. Exogenous application of 20-HETE attenuated, whereas inhibition of 20-HETE production with HET-0016 increased the open state probabilities (NPo) of 71pS and 161pS KCa single-channel currents recorded from astrocytes. Exposure of isolated cerebral arterial myocytes to conditioned media from cultured astrocytes caused shortening of the length of freshly isolated cerebral arterial myocytes that was not evident following inhibition of astrocyte 20-HETE synthesis and action. These findings suggest that astrocytes not only release vasodilator EETs in response to mGluR stimulation but also synthetize and release the cerebral arterial myocyte constrictor 20-HETE that also functions as an endogenous inhibitor of the activity of two types of KCa channel currents found in astrocytes.
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Affiliation(s)
- Debebe Gebremedhin
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - David X Zhang
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Koryn A Carver
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Nicole Rau
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Kevin R Rarick
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, United States
| | - David R Harder
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States; Clement Zablocki VA Medical Center, Milwaukee, WI 53226, United States.
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34
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Association of serum VEGF levels with prefrontal cortex volume in schizophrenia. Mol Psychiatry 2016; 21:686-92. [PMID: 26169975 DOI: 10.1038/mp.2015.96] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/05/2015] [Accepted: 06/01/2015] [Indexed: 12/30/2022]
Abstract
A large body of evidence indicates alterations in brain regional cellular energy metabolism and blood flow in schizophrenia. Among the different molecules regulating blood flow, vascular endothelial growth factor (VEGF) is generally accepted as the major factor involved in the process of angiogenesis. In the present study, we examined whether peripheral VEGF levels correlate with changes in the prefrontal cortex (PFC) volume in patients with schizophrenia and in healthy controls. Whole-blood samples were obtained from 96 people with schizophrenia or schizoaffective disorder and 83 healthy controls. Serum VEGF protein levels were analyzed by enzyme-linked immunosorbent assay, whereas quantitative PCR was performed to measure interleukin-6 (IL-6, a pro-inflammatory marker implicated in schizophrenia) mRNA levels in the blood samples. Structural magnetic resonance imaging scans were obtained using a 3T Achieva scanner on a subset of 59 people with schizophrenia or schizoaffective disorder and 65 healthy controls, and prefrontal volumes were obtained using FreeSurfer software. As compared with healthy controls, individuals with schizophrenia had a significant increase in log-transformed mean serum VEGF levels (t(177)=2.9, P=0.005). A significant inverse correlation (r=-0.40, P=0.002) between serum VEGF and total frontal pole volume was found in patients with schizophrenia/schizoaffective disorder. Moreover, we observed a significant positive association (r=0.24, P=0.03) between serum VEGF and IL-6 mRNA levels in patients with schizophrenia. These findings suggest an association between serum VEGF and inflammation, and that serum VEGF levels are related to structural abnormalities in the PFC of people with schizophrenia.
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35
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Leng Y, Wang J, Wang Z, Liao HM, Wei M, Leeds P, Chuang DM. Valproic Acid and Other HDAC Inhibitors Upregulate FGF21 Gene Expression and Promote Process Elongation in Glia by Inhibiting HDAC2 and 3. Int J Neuropsychopharmacol 2016; 19:pyw035. [PMID: 27207921 PMCID: PMC5006201 DOI: 10.1093/ijnp/pyw035] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 04/18/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Fibroblast growth factor 21, a novel regulator of glucose and lipid metabolism, has robust protective properties in neurons. However, its expression and function in glia are unknown. Valproic acid, a mood stabilizer and anticonvulsant, is a histone deacetylase inhibitor and a dynamic gene regulator. We investigated whether histone deacetylase inhibition by valproic acid and other inhibitors upregulates fibroblast growth factor 21 expression and, if so, sought to identify the histone deacetylase isoform(s) involved and their role in altering glial cell morphology. METHODS C6 glioma or primary cortical glial cultures were treated with histone deacetylase inhibitors, and fibroblast growth factor 21 levels and length of cell processes were subsequently measured. Histone deacetylase 1, 2, or 3 was also knocked down to detect which isoform was involved in regulating fibroblast growth factor 21 mRNA levels. Finally, knockdown and overexpression of fibroblast growth factor 21 were performed to determine whether it played a role in regulating cell process length. RESULTS Treatment of C6 cells or primary glial cultures with valproic acid elevated fibroblast growth factor 21 mRNA levels, extended cell process length, and markedly increased acetylated histone-H3 levels. Other histone deacetylase inhibitors including pan- and class I-specific inhibitors, or selective knockdown of histone deacetylase 2 or 3 isoform produced similar effects. Knockdown or overexpression of fibroblast growth factor 21 significantly decreased or increased C6 cell process length, respectively. CONCLUSIONS In glial cell line and primary glia, using pharmacological inhibition and selective gene silencing of histone deacetylases to boost fibroblast growth factor 21 mRNA levels results in elongation of cell processes. Our study provides a new mechanism via which histone deacetylase 2 and 3 participate in upregulating fibroblast growth factor 21 transcription and extending process outgrowth in glia.
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Affiliation(s)
- Yan Leng
- Molecular Neurobiology Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD.
| | | | | | | | | | | | - De-Maw Chuang
- Molecular Neurobiology Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD.
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Stokum JA, Gerzanich V, Simard JM. Molecular pathophysiology of cerebral edema. J Cereb Blood Flow Metab 2016; 36:513-38. [PMID: 26661240 PMCID: PMC4776312 DOI: 10.1177/0271678x15617172] [Citation(s) in RCA: 357] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/21/2015] [Accepted: 10/22/2015] [Indexed: 12/25/2022]
Abstract
Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema.
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Affiliation(s)
- Jesse A Stokum
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, USA
| | - J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, USA Department of Pathology, University of Maryland School of Medicine, Baltimore, USA Department of Physiology, University of Maryland School of Medicine, Baltimore, USA
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Posada-Duque RA, Barreto GE, Cardona-Gomez GP. Protection after stroke: cellular effectors of neurovascular unit integrity. Front Cell Neurosci 2014; 8:231. [PMID: 25177270 PMCID: PMC4132372 DOI: 10.3389/fncel.2014.00231] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/24/2014] [Indexed: 12/16/2022] Open
Abstract
Neurological disorders are prevalent worldwide. Cerebrovascular diseases (CVDs), which account for 55% of all neurological diseases, are the leading cause of permanent disability, cognitive and motor disorders and dementia. Stroke affects the function and structure of blood-brain barrier, the loss of cerebral blood flow regulation, oxidative stress, inflammation and the loss of neural connections. Currently, no gold standard treatments are available outside the acute therapeutic window to improve outcome in stroke patients. Some promising candidate targets have been identified for the improvement of long-term recovery after stroke, such as Rho GTPases, cell adhesion proteins, kinases, and phosphatases. Previous studies by our lab indicated that Rho GTPases (Rac and RhoA) are involved in both tissue damage and survival, as these proteins are essential for the morphology and movement of neurons, astrocytes and endothelial cells, thus playing a critical role in the balance between cell survival and death. Treatment with a pharmacological inhibitor of RhoA/ROCK blocks the activation of the neurodegeneration cascade. In addition, Rac and synaptic adhesion proteins (p120 catenin and N-catenin) play critical roles in protection against cerebral infarction and in recovery by supporting the neurovascular unit and cytoskeletal remodeling activity to maintain the integrity of the brain parenchyma. Interestingly, neuroprotective agents, such as atorvastatin, and CDK5 silencing after cerebral ischemia and in a glutamate-induced excitotoxicity model may act on the same cellular effectors to recover neurovascular unit integrity. Therefore, future efforts must focus on individually targeting the structural and functional roles of each effector of neurovascular unit and the interactions in neural and non-neural cells in the post-ischemic brain and address how to promote the recovery or prevent the loss of homeostasis in the short, medium and long term.
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Affiliation(s)
- Rafael Andres Posada-Duque
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, Sede de Investigación Universitaria (SIU), University of Antioquia UdeA Medellín, Colombia
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana Bogotá D.C., Colombia
| | - Gloria Patricia Cardona-Gomez
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, Sede de Investigación Universitaria (SIU), University of Antioquia UdeA Medellín, Colombia
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Carver KA, Lourim D, Tryba AK, Harder DR. Rhythmic expression of cytochrome P450 epoxygenases CYP4x1 and CYP2c11 in the rat brain and vasculature. Am J Physiol Cell Physiol 2014; 307:C989-98. [PMID: 25055826 DOI: 10.1152/ajpcell.00401.2013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Mammals have circadian variation in blood pressure, heart rate, vascular tone, thrombotic tendency, and cerebral blood flow (CBF). These changes may be in part orchestrated by circadian variation in clock gene expression within cells comprising the vasculature that modulate blood flow (e.g., fibroblasts, cerebral vascular smooth muscle cells, astrocytes, and endothelial cells). However, the downstream mechanisms that underlie circadian changes in blood flow are unknown. Cytochrome P450 epoxygenases (Cyp4x1 and Cyp2c11) are expressed in the brain and vasculature and metabolize arachidonic acid (AA) to form epoxyeicosatrienoic acids (EETs). EETs are released from astrocytes, neurons, and vascular endothelial cells and act as potent vasodilators, increasing blood flow. EETs released in response to increases in neural activity evoke a corresponding increase in blood flow known as the functional hyperemic response. We examine the hypothesis that Cyp2c11 and Cyp4x1 expression and EETs production vary in a circadian manner in the rat brain and cerebral vasculature. RT-PCR revealed circadian/diurnal expression of clock and clock-controlled genes as well as Cyp4x1 and Cyp2c11, within the rat hippocampus, middle cerebral artery, inferior vena cava, hippocampal astrocytes and rat brain microvascular endothelial cells. Astrocyte and endothelial cell culture experiments revealed rhythmic variation in Cyp4x1 and Cyp2c11 gene and protein expression with a 12-h period and parallel rhythmic production of EETs. Our data suggest there is circadian regulation of Cyp4x1 and Cyp2c11 gene expression. Such rhythmic EETs production may contribute to circadian changes in blood flow and alter risk of adverse cardiovascular events throughout the day.
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Affiliation(s)
- Koryn A Carver
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - David Lourim
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Andrew K Tryba
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin
| | - David R Harder
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin
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Cerebral blood flow is an earlier indicator of perfusion abnormalities than cerebral blood volume in Alzheimer's disease. J Cereb Blood Flow Metab 2014; 34:654-9. [PMID: 24424381 PMCID: PMC3982085 DOI: 10.1038/jcbfm.2013.241] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/23/2013] [Accepted: 12/09/2013] [Indexed: 11/09/2022]
Abstract
The purpose of this study was to elucidate whether cerebral blood flow (CBF) can better characterize perfusion abnormalities in predementia stages of Alzheimer's disease (AD) than cerebral blood volume (CBV) and whether cortical atrophy is more associated with decreased CBV or with decreased CBF. We compared measurements of CBV, CBF, and mean cortical thickness obtained from magnetic resonance images in a group of healthy controls, patients with mild cognitive impairment (MCI) who converted to AD after 2 years of clinical follow-up (MCI-c), and patients with mild AD. A significant decrease in perfusion was detected in the parietal lobes of the MCI-c patients with CBF parametric maps but not with CBV maps. In the MCI-c group, a negative correlation between CBF values and cortical thickness in the right parahippocampal gyrus suggests an increase in CBF that depends on cortical atrophy in predementia stages of AD. Our study also suggests that CBF deficits appear before CBV deficits in the progression of AD, as CBV abnormalities were only detected at the AD stage, whereas CBF changes were already detected in the MCI stage. These results confirm the hypothesis that CBF is a more sensitive parameter than CBV for perfusion abnormalities in MCI-c patients.
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Abstract
Cerebral blood flow is controlled by two crucial processes, cerebral autoregulation (CA) and neurovascular coupling (NVC) or functional hyperemia. Whereas CA ensures constant blood flow over a wide range of systemic pressures, NVC ensures rapid spatial and temporal increases in cerebral blood flow in response to neuronal activation. The focus of this review is to discuss the cellular mechanisms by which astrocytes contribute to the regulation of vascular tone in terms of their participation in NVC and, to a lesser extent, CA. We discuss evidence for the various signaling modalities by which astrocytic activation leads to vasodilation and vasoconstriction of parenchymal arterioles. Moreover, we provide a rationale for the contribution of astrocytes to pressure-induced increases in vascular tone via the vasoconstrictor 20-HETE (a downstream metabolite of arachidonic acid). Along these lines, we highlight the importance of the transient receptor potential channel of the vanilloid family (TRPV4) as a key molecular determinant in the regulation of vascular tone in cerebral arterioles. Finally, we discuss current advances in the technical tools available to study NVC mechanisms in the brain as it relates to the participation of astrocytes.
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Nitric oxide inactivation mechanisms in the brain: role in bioenergetics and neurodegeneration. Int J Cell Biol 2012; 2012:391914. [PMID: 22719764 PMCID: PMC3376480 DOI: 10.1155/2012/391914] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 04/18/2012] [Indexed: 10/28/2022] Open
Abstract
During the last decades nitric oxide ((•)NO) has emerged as a critical physiological signaling molecule in mammalian tissues, notably in the brain. (•)NO may modify the activity of regulatory proteins via direct reaction with the heme moiety, or indirectly, via S-nitrosylation of thiol groups or nitration of tyrosine residues. However, a conceptual understanding of how (•)NO bioactivity is carried out in biological systems is hampered by the lack of knowledge on its dynamics in vivo. Key questions still lacking concrete and definitive answers include those related with quantitative issues of its concentration dynamics and diffusion, summarized in the how much, how long, and how far trilogy. For instance, a major problem is the lack of knowledge of what constitutes a physiological (•)NO concentration and what constitutes a pathological one and how is (•)NO concentration regulated. The ambient (•)NO concentration reflects the balance between the rate of synthesis and the rate of breakdown. Much has been learnt about the mechanism of (•)NO synthesis, but the inactivation pathways of (•)NO has been almost completely ignored. We have recently addressed these issues in vivo on basis of microelectrode technology that allows a fine-tuned spatial and temporal measurement (•)NO concentration dynamics in the brain.
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Harder DR, Narayanan J, Gebremedhin D. Pressure-induced myogenic tone and role of 20-HETE in mediating autoregulation of cerebral blood flow. Am J Physiol Heart Circ Physiol 2011; 300:H1557-65. [PMID: 21257913 PMCID: PMC3283039 DOI: 10.1152/ajpheart.01097.2010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 01/20/2011] [Indexed: 11/22/2022]
Abstract
While myogenic force in response to a changing arterial pressure has been described early in the 20th century, it was not until 1984 that the effect of a sequential increase in intraluminal pressure on cannulated cerebral arterial preparations was found to result in pressure-dependent membrane depolarization associated with spike generation and reduction in lumen diameter. Despite a great deal of effort by different laboratories and investigators, the identification of the existence of a mediator of the pressure-induced myogenic constriction in arterial muscle remained a challenge. It was the original finding by our laboratory that demonstrated the capacity of cerebral arterial muscle cells to express the cytochrome P-450 4A enzyme that catalyzes the formation of the potent vasoconstrictor 20-hydroxyeicosatetraenoic acid (20-HETE) from arachidonic acid, the production of which in cerebral arterial muscle cells increases with the elevation in intravascular pressure. 20-HETE activates protein kinase C and causes the inhibition of Ca(²+)-activated K(+) channels, depolarizes arterial muscle cell membrane, and activates L-type Ca(²+) channel to increase intracellular Ca(²+) levels and evoke vasoconstriction. The inhibition of 20-HETE formation attenuates pressure-induced arterial myogenic constriction in vitro and blunts the autoregulation of cerebral blood flow in vivo. We suggest that the formation and action of cytochrome P-450-derived 20-HETE in cerebral arterial muscle could play a critically important role in the control of cerebral arterial tone and the autoregulation of cerebral blood flow under physiological conditions.
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Affiliation(s)
- David R Harder
- Medical College of Wisconsin, Clinical and Translational Science Inst., Milwaukee, WI 53226, USA.
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Filosa JA. Vascular tone and neurovascular coupling: considerations toward an improved in vitro model. FRONTIERS IN NEUROENERGETICS 2010; 2:16. [PMID: 20802803 PMCID: PMC2928708 DOI: 10.3389/fnene.2010.00016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 06/28/2010] [Indexed: 11/13/2022]
Abstract
Neurovascular research has made significant strides toward understanding how the brain neurovascular unit accomplishes rapid and spatial increases in blood flow following neuronal activation. Among the experimental models used, the in vitro brain slice preparation provides unique information revealing the potential signals and cellular mechanisms involved in functional hyperemia. The most crucial limitation of this model, however, is the lack of intraluminal pressure and flow in the vessels being studied. Moreover, differences in basal vascular tone have led to varied interpretations regarding the polarity of vascular responses following neuron-to-glial stimulation. Given the complexity of astrocyte-induced neurovascular responses, we propose the use of a modified in vitro brain slice preparation, where intraluminal arteriolar pressure and flow are retained. Throughout this review, we discuss the advantages and disadvantages to be considered when using brain slices for neurovascular studies. Potential ways to overcome the current limitations are proposed.
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Affiliation(s)
- Jessica A. Filosa
- Department of Physiology, Medical College of GeorgiaAugusta, GA, USA
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44
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Abstract
Neuronal activity is communicated to the cerebral vasculature so that adequate perfusion of brain tissue is maintained at all levels of neuronal metabolism. An increase in neuronal activity is accompanied by vasodilation and an increase in local cerebral blood flow. This process, known as neurovascular coupling (NVC) or functional hyperemia, is essential for cerebral homeostasis and survival. Neuronal activity is encoded in astrocytic Ca(2+) signals that travel to astrocytic processes (;endfeet') encasing parenchymal arterioles within the brain. Astrocytic Ca(2+) signals cause the release of vasoactive substances to cause relaxation, and in some circumstances contraction, of the smooth muscle cells (SMCs) of parenchymal arterioles to modulate local cerebral blood flow. Activation of potassium channels in the SMCs has been proposed to mediate NVC. Here, the current state of knowledge of NVC and potassium channels in parenchymal arterioles is reviewed.
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Affiliation(s)
- Kathryn M Dunn
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, VT 05405, USA
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45
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Parasympathetic tonic dilatory influences on cerebral vessels. Auton Neurosci 2009; 147:101-4. [PMID: 19195933 DOI: 10.1016/j.autneu.2009.01.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 01/14/2009] [Accepted: 01/19/2009] [Indexed: 11/23/2022]
Abstract
Parasympathetic nerves from the pterygopalatine ganglia may participate in development of cluster headaches, in vascular responses to hypertension and in modulation of damage due to stroke. Stimulation of the nerves elicits cerebral vasodilatation, but it is not known if the nerves tonically influence cerebrovascular tone. We hypothesized that parasympathetics provide a tonic vasodilator influence and tested that hypothesis by measuring cerebral blood flow in anesthetized rats before and after removal of a pterygopalatine ganglion. Ganglion removal led to reduced cerebral blood flow without changing blood pressure. Thus, parasympathetic nerves provide tonic vasodilatory input to cerebral blood vessels.
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Luria A, Weldon SM, Kabcenell AK, Ingraham RH, Matera D, Jiang H, Gill R, Morisseau C, Newman JW, Hammock BD. Compensatory mechanism for homeostatic blood pressure regulation in Ephx2 gene-disrupted mice. J Biol Chem 2006; 282:2891-8. [PMID: 17135253 PMCID: PMC2040337 DOI: 10.1074/jbc.m608057200] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Arachidonic acid-derived epoxides, epoxyeicosatrienoic acids, are important regulators of vascular homeostasis and inflammation, and therefore manipulation of their levels is a potentially useful pharmacological strategy. Soluble epoxide hydrolase converts epoxyeicosatrienoic acids to their corresponding diols, dihydroxyeicosatrienoic acids, modifying or eliminating the function of these oxylipins. To better understand the phenotypic impact of Ephx2 disruption, two independently derived colonies of soluble epoxide hydrolase-null mice were compared. We examined this genotype evaluating protein expression, biofluid oxylipin profile, tissue oxylipin production capacity, and blood pressure. Ephx2 gene disruption eliminated soluble epoxide hydrolase protein expression and activity in liver, kidney, and heart from each colony. Plasma levels of epoxy fatty acids were increased, and fatty acid diols levels were decreased, while measured levels of lipoxygenase- and cyclooxygenase-dependent oxylipins were unchanged. Liver and kidney homogenates also show elevated epoxide fatty acids. However, in whole kidney homogenate a 4-fold increase in the formation of 20-hydroxyeicosatetraenoic acid was measured along with a 3-fold increase in lipoxygenase-derived hydroxylation and prostanoid production. Unlike previous reports, however, neither Ephx2-null colony showed alterations in basal blood pressure. Finally, the soluble epoxide hydrolase-null mice show a survival advantage following acute systemic inflammation. The data suggest that blood pressure homeostasis may be achieved by increasing production of the vasoconstrictor, 20-hydroxyeicosatetraenoic acid in the kidney of the Ephx2-null mice. This shift in renal metabolism is likely a metabolic compensation for the loss of the soluble epoxide hydrolase gene.
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Affiliation(s)
- Ayala Luria
- Department of Entomology, University of California, Davis, California 95616
| | - Steven M. Weldon
- Department of Cardiovascular Disease, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877
| | - Alisa K. Kabcenell
- Department of Cardiovascular Disease, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877
| | - Richard H. Ingraham
- Department of Cardiovascular Disease, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877
| | - Damian Matera
- Department of Cardiovascular Disease, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877
| | - Huiping Jiang
- Department of Translational Science, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877
| | - Rajan Gill
- Department of Entomology, University of California, Davis, California 95616
- Department of Nutrition, University of California, Davis, California 95616
| | - Christophe Morisseau
- Department of Entomology, University of California, Davis, California 95616
- Cancer Research Center, University of California, Davis, California 95616
| | - John W. Newman
- Department of Entomology, University of California, Davis, California 95616
- Department of Nutrition, University of California, Davis, California 95616
- United State Department of Agriculture, ARS, Western Human Nutrition Research Center, Davis, California 95616
| | - Bruce D. Hammock
- Department of Entomology, University of California, Davis, California 95616
- Cancer Research Center, University of California, Davis, California 95616
- To whom correspondence should be addressed: Dept. of Entomology, University of California Davis, CA 95616. Tel.: 530-752-7519; Fax: 530-752-1537; E-mail:
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Abstract
From a structural perspective, the predominant glial cell of the central nervous system, the astrocyte, is positioned to regulate synaptic transmission and neurovascular coupling: the processes of one astrocyte contact tens of thousands of synapses, while other processes of the same cell form endfeet on capillaries and arterioles. The application of subcellular imaging of Ca2+ signaling to astrocytes now provides functional data to support this structural notion. Astrocytes express receptors for many neurotransmitters, and their activation leads to oscillations in internal Ca2+. These oscillations induce the accumulation of arachidonic acid and the release of the chemical transmitters glutamate, d-serine, and ATP. Ca2+ oscillations in astrocytic endfeet can control cerebral microcirculation through the arachidonic acid metabolites prostaglandin E2 and epoxyeicosatrienoic acids that induce arteriole dilation, and 20-HETE that induces arteriole constriction. In addition to actions on the vasculature, the release of chemical transmitters from astrocytes regulates neuronal function. Astrocyte-derived glutamate, which preferentially acts on extrasynaptic receptors, can promote neuronal synchrony, enhance neuronal excitability, and modulate synaptic transmission. Astrocyte-derived d-serine, by acting on the glycine-binding site of the N-methyl-d-aspartate receptor, can modulate synaptic plasticity. Astrocyte-derived ATP, which is hydrolyzed to adenosine in the extracellular space, has inhibitory actions and mediates synaptic cross-talk underlying heterosynaptic depression. Now that we appreciate this range of actions of astrocytic signaling, some of the immediate challenges are to determine how the astrocyte regulates neuronal integration and how both excitatory (glutamate) and inhibitory signals (adenosine) provided by the same glial cell act in concert to regulate neuronal function.
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Affiliation(s)
- Philip G Haydon
- Silvio Conte Center for Integration at the Tripartite Synapse, Department of Neuroscience, University of Pennsylvania School of Medicine, PA 19104, USA.
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Abstract
Brain perfusion is tightly coupled to neuronal activity, is commonly used to monitor normal or pathological brain function, and is a direct reflection of the interactions that occur between neuronal signals and blood vessels. Cerebral blood vessels at the surface and within the brain are surrounded by nerve fibers that originate, respectively, from peripheral nerve ganglia and intrinsic brain neurons. Although of different origin and targeting distinct vascular beds, these "perivascular nerves" fulfill similar roles related to cerebrovascular functions, a major one being to regulate their tone and, therein, brain perfusion. This utmost function, which underlies the signals used in functional neuroimaging techniques and which can be jeopardized in pathologies such as Alzheimer's disease, stroke, and migraine headache, is thus regulated at several levels. Recently, new insights into our understanding of how neural input regulate cerebrovascular tone resulted in the rediscovery of the functional "neurovascular unit." These remarkable advances suggest that neuron-driven changes in vascular tone result from interactions that involve all components of the neurovascular unit, transducing neuronal signals into vasomotor responses not only through direct interaction between neurons and vessels but also indirectly via the perivascular astrocytes. Neurovascular coupling is thus determined by chemical signals released from activated perivascular nerves and astrocytes that alter vascular tone to locally adjust perfusion to the spatial and temporal changes in brain activity.
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Affiliation(s)
- Edith Hamel
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, 3801 University St., Montréal, QC, Canada, H3A 2B4.
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Leffler CW, Parfenova H, Jaggar JH, Wang R. Carbon monoxide and hydrogen sulfide: gaseous messengers in cerebrovascular circulation. J Appl Physiol (1985) 2006; 100:1065-76. [PMID: 16467393 PMCID: PMC1363746 DOI: 10.1152/japplphysiol.00793.2005] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
This review focuses on two gaseous cellular messenger molecules, CO and H2S, that are involved in cerebrovascular flow regulation. CO is a dilatory mediator in active hyperemia, autoregulation, hypoxic dilation, and counteracting vasoconstriction. It is produced from heme by a constitutively expressed enzyme [heme oxygenase (HO)-2] expressed highly in the brain and by an inducible enzyme (HO-1). CO production is regulated by controlling substrate availability, HO-2 catalytic activity, and HO-1 expression. CO dilates arterioles by binding to heme that is bound to large-conductance Ca2+-activated K+ channels. This binding elevates channel Ca2+ sensitivity, that increases coupling of Ca2+ sparks to large-conductance Ca2+-activated K+ channel openings and, thereby, hyperpolarizes the vascular smooth muscle. In addition to dilating blood vessels, CO can either inhibit or accentuate vascular cell proliferation and apoptosis, depending on conditions. H2S may also function as a cerebrovascular dilator. It is produced in vascular smooth muscle cells by hydrolysis of l-cysteine catalyzed by cystathione gamma-lyase (CSE). H2S dilates arterioles at physiologically relevant concentrations via activation of ATP-sensitive K+ channels. In addition to dilating blood vessels, H2S promotes apoptosis of vascular smooth muscle cells and inhibits proliferation-associated vascular remodeling. Thus both CO and H2S modulate the function and the structure of circulatory system. Both the HO-CO and CSE-H2S systems have potential to interact with NO and prostanoids in the cerebral circulation. Much of the physiology and biochemistry of HO-CO and CSE-H2S in the cerebral circulation remains open for exploration.
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Affiliation(s)
- Charles W Leffler
- Dept. of Physiology, University of Tennessee Health Science Center, 894 Union Ave., Memphis, TN 38163, USA.
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Hanson DR, Gottesman II. Theories of schizophrenia: a genetic-inflammatory-vascular synthesis. BMC MEDICAL GENETICS 2005; 6:7. [PMID: 15707482 PMCID: PMC554096 DOI: 10.1186/1471-2350-6-7] [Citation(s) in RCA: 195] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Accepted: 02/11/2005] [Indexed: 12/13/2022]
Abstract
BACKGROUND Schizophrenia, a relatively common psychiatric syndrome, affects virtually all brain functions yet has eluded explanation for more than 100 years. Whether by developmental and/or degenerative processes, abnormalities of neurons and their synaptic connections have been the recent focus of attention. However, our inability to fathom the pathophysiology of schizophrenia forces us to challenge our theoretical models and beliefs. A search for a more satisfying model to explain aspects of schizophrenia uncovers clues pointing to genetically mediated CNS microvascular inflammatory disease. DISCUSSION A vascular component to a theory of schizophrenia posits that the physiologic abnormalities leading to illness involve disruption of the exquisitely precise regulation of the delivery of energy and oxygen required for normal brain function. The theory further proposes that abnormalities of CNS metabolism arise because genetically modulated inflammatory reactions damage the microvascular system of the brain in reaction to environmental agents, including infections, hypoxia, and physical trauma. Damage may accumulate with repeated exposure to triggering agents resulting in exacerbation and deterioration, or healing with their removal. There are clear examples of genetic polymorphisms in inflammatory regulators leading to exaggerated inflammatory responses. There is also ample evidence that inflammatory vascular disease of the brain can lead to psychosis, often waxing and waning, and exhibiting a fluctuating course, as seen in schizophrenia. Disturbances of CNS blood flow have repeatedly been observed in people with schizophrenia using old and new technologies. To account for the myriad of behavioral and other curious findings in schizophrenia such as minor physical anomalies, or reported decreased rates of rheumatoid arthritis and highly visible nail fold capillaries, we would have to evoke a process that is systemic such as the vascular and immune/inflammatory systems. SUMMARY A vascular-inflammatory theory of schizophrenia brings together environmental and genetic factors in a way that can explain the diversity of symptoms and outcomes observed. If these ideas are confirmed, they would lead in new directions for treatments or preventions by avoiding inducers of inflammation or by way of inflammatory modulating agents, thus preventing exaggerated inflammation and consequent triggering of a psychotic episode in genetically predisposed persons.
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Affiliation(s)
- Daniel R Hanson
- Department of Psychiatry, VA Medical Center (116A), One Veterans Drive, Minneapolis, MN, 55417 and Departments of Psychiatry & Psychology, University of Minnesota, USA
| | - Irving I Gottesman
- Departments of Psychiatry & Psychology, University of Minnesota, Minneapolis, MN 55454, USA
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