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Wu PZ, Yao J, Meng B, Qin YB, Cao S. Blood-nerve barrier enhances chronic postsurgical pain via the HIF-1α/ aquaporin-1 signaling axis. BMC Anesthesiol 2023; 23:381. [PMID: 37990154 PMCID: PMC10662690 DOI: 10.1186/s12871-023-02306-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 10/06/2023] [Indexed: 11/23/2023] Open
Abstract
BACKGROUND Blood nerve barrier (BNB) participates in the development of neuropathic pain. AQP1 is involved in peripheral pain perception and is negatively correlated with HIF-1α phenotype, which regulates endothelial permeability. However, the role of HIF-1α-AQP1-mediated BNB dysfunction in Chronic Postsurgical Pain (CPSP) has not been reported. METHODS Male Sprague-Dawley rats were randomized into 5 groups: (i) Naive group; (ii) Sham group; (iii) SMIR group: skin/muscle incision and retraction for one hour. Behavioral tests were performed for the three groups, BNB vascular permeability and western blotting were conducted to determine HIF-1α and AQP1 protein expression. (iv) The SMIR + HIF-1α inhibitor group; (v) SMIR + DMSO group. Rats in the two groups were administered with HIF-1α inhibitor (2ME2) or DMSO intraperitoneally on the third day post-SMIR surgery followed by performance of behavioral tests, BNB permeability assessment, and determination of HIF-1α, AQP1 and NF200 protein levels. RESULTS The permeability of BNB was significantly increased and the expression of AQP1 was downregulated on the 3rd and 7th days post-operation. AQP1 is mainly located in neurons and NF200, CGRP-positive nerve fibers. HIF-1α was highly expressed on the third day post-operation. HIF-1α inhibitor reversed the decrease in AQP1 expression and increase in NF200 expression, barrier permeability and hyperalgesia induced by SMIR on the 3rd day post-surgery. CONCLUSIONS Early dysfunction of BNB mediated by HIF-1α/AQP1 activated by SMIR may be an important mechanism to promote acute postoperative painful transformation of CPSP. Preadaptive protection of endothelial cells around nerve substructures may be an important countermeasure to inhibit CPSP transformation. Early impairment of BNB function mediated by HIF-1α/AQP1 activated by SMIR may be an important mechanism for promoting acute postoperative pain transformation of CPSP.
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Affiliation(s)
- Pei-Zhi Wu
- Department of Anesthesiology, Affiliated Hospital and Medical School of Nantong University, No. 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Ju Yao
- Department of Anesthesiology, Affiliated Hospital and Medical School of Nantong University, No. 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Bei Meng
- Department of Anesthesiology, Affiliated Hospital and Medical School of Nantong University, No. 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Yi-Bin Qin
- Department of Anesthesiology, Affiliated Hospital and Medical School of Nantong University, No. 20 Xisi Road, Nantong, 226001, Jiangsu, China
| | - Su Cao
- Department of Anesthesiology, Affiliated Hospital and Medical School of Nantong University, No. 20 Xisi Road, Nantong, 226001, Jiangsu, China.
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Ben-Kraiem A, Sauer RS, Norwig C, Popp M, Bettenhausen AL, Atalla MS, Brack A, Blum R, Doppler K, Rittner HL. Selective blood-nerve barrier leakiness with claudin-1 and vessel-associated macrophage loss in diabetic polyneuropathy. J Mol Med (Berl) 2021; 99:1237-1250. [PMID: 34018017 PMCID: PMC8367905 DOI: 10.1007/s00109-021-02091-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 04/26/2021] [Accepted: 05/10/2021] [Indexed: 12/19/2022]
Abstract
Diabetic polyneuropathy (DPN) is the most common complication in diabetes and can be painful in up to 26% of all diabetic patients. Peripheral nerves are shielded by the blood-nerve barrier (BNB) consisting of the perineurium and endoneurial vessels. So far, there are conflicting results regarding the role and function of the BNB in the pathophysiology of DPN. In this study, we analyzed the spatiotemporal tight junction protein profile, barrier permeability, and vessel-associated macrophages in Wistar rats with streptozotocin-induced DPN. In these rats, mechanical hypersensitivity developed after 2 weeks and loss of motor function after 8 weeks, while the BNB and the blood-DRG barrier were leakier for small, but not for large molecules after 8 weeks only. The blood-spinal cord barrier remained sealed throughout the observation period. No gross changes in tight junction protein or cytokine expression were observed in all barriers to blood. However, expression of Cldn1 mRNA in perineurium was specifically downregulated in conjunction with weaker vessel-associated macrophage shielding of the BNB. Our results underline the role of specific tight junction proteins and BNB breakdown in DPN maintenance and differentiate DPN from traumatic nerve injury. Targeting claudins and sealing the BNB could stabilize pain and prevent further nerve damage. KEY MESSAGES: • In diabetic painful neuropathy in rats: • Blood nerve barrier and blood DRG barrier are leaky for micromolecules. • Perineurial Cldn1 sealing the blood nerve barrier is specifically downregulated. • Endoneurial vessel-associated macrophages are also decreased. • These changes occur after onset of hyperalgesia thereby maintaining rather than inducing pain.
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Affiliation(s)
- Adel Ben-Kraiem
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Reine-Solange Sauer
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Carla Norwig
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Maria Popp
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Anna-Lena Bettenhausen
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Mariam Sobhy Atalla
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Alexander Brack
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Robert Blum
- Institute of Clinical Neurobiology, University Hospital of Würzburg, 97078, Würzburg, Germany
- Department of Neurology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Kathrin Doppler
- Department of Neurology, University Hospital of Würzburg, 97080, Würzburg, Germany
| | - Heike Lydia Rittner
- Center for Interdisciplinary Pain Medicine, Department of Anesthesiology, University Hospital of Würzburg, 97080, Würzburg, Germany.
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Maiuolo J, Gliozzi M, Musolino V, Carresi C, Nucera S, Macrì R, Scicchitano M, Bosco F, Scarano F, Ruga S, Zito MC, Oppedisano F, Mollace R, Paone S, Palma E, Muscoli C, Mollace V. The Role of Endothelial Dysfunction in Peripheral Blood Nerve Barrier: Molecular Mechanisms and Pathophysiological Implications. Int J Mol Sci 2019; 20:ijms20123022. [PMID: 31226852 PMCID: PMC6628074 DOI: 10.3390/ijms20123022] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/14/2019] [Accepted: 06/16/2019] [Indexed: 02/06/2023] Open
Abstract
The exchange of solutes between the blood and the nerve tissue is mediated by specific and high selective barriers in order to ensure the integrity of the different compartments of the nervous system. At peripheral level, this function is maintained by the Blood Nerve Barrier (BNB) that, in the presence, of specific stressor stimuli can be damaged causing the onset of neurodegenerative processes. An essential component of BNB is represented by the endothelial cells surrounding the sub-structures of peripheral nerves and increasing evidence suggests that endothelial dysfunction can be considered a leading cause of the nerve degeneration. The purpose of this review is to highlight the main mechanisms involved in the impairment of endothelial cells in specific diseases associated with peripheral nerve damage, such as diabetic neuropathy, erectile dysfunction and inflammation of the sciatic nerve.
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Affiliation(s)
- Jessica Maiuolo
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Micaela Gliozzi
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Vincenzo Musolino
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Cristina Carresi
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Saverio Nucera
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
| | - Roberta Macrì
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Miriam Scicchitano
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
| | - Francesca Bosco
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Federica Scarano
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
| | - Stefano Ruga
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
| | - Maria Caterina Zito
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
| | - Francesca Oppedisano
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Rocco Mollace
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Sara Paone
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Ernesto Palma
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
| | - Carolina Muscoli
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele, Via di Valcannuta 247, 00133 Rome, Italy.
| | - Vincenzo Mollace
- Interregional Research Center for Food Safety and Health (IRC-FSH), Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy.
- Nutramed Societa' Consortile A Responsabilita' Limitata (S.c.a.r.l.), Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy.
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele, Via di Valcannuta 247, 00133 Rome, Italy.
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Di Spiezio A, Sandin ES, Dore R, Müller-Fielitz H, Storck SE, Bernau M, Mier W, Oster H, Jöhren O, Pietrzik CU, Lehnert H, Schwaninger M. The LepR-mediated leptin transport across brain barriers controls food reward. Mol Metab 2018; 8:13-22. [PMID: 29254602 PMCID: PMC5985039 DOI: 10.1016/j.molmet.2017.12.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/26/2017] [Accepted: 12/02/2017] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Leptin is a key hormone in the control of appetite and body weight. Predominantly produced by white adipose tissue, it acts on the brain to inhibit homeostatic feeding and food reward. Leptin has free access to circumventricular organs, such as the median eminence, but entry into other brain centers is restricted by the blood-brain and blood-CSF barriers. So far, it is unknown for which of its central effects leptin has to penetrate brain barriers. In addition, the mechanisms mediating the transport across barriers are unclear although high expression in brain barriers suggests an important role of the leptin receptor (LepR). METHODS We selectively deleted LepR in brain endothelial and epithelial cells of mice (LepRbeKO). The expression of LepR in fenestrated vessels of the periphery and the median eminence as well as in tanycytes was not affected. RESULTS Perfusion studies showed that leptin uptake by the brain depended on LepR in brain barriers. When being fed with a rewarding high-fat diet LepRbeKO mice gained more body weight than controls. The aggravated obesity of LepRbeKO mice was due to hyperphagia and a higher sensitivity to food reward. CONCLUSIONS The LepR-mediated transport of leptin across brain barriers in endothelial cells lining microvessels and in epithelial cells of the choroid plexus controls food reward but is apparently not involved in homeostatic control of feeding.
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Affiliation(s)
- Alessandro Di Spiezio
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Elvira Sonia Sandin
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Riccardo Dore
- Department of Internal Medicine, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Helge Müller-Fielitz
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Steffen E Storck
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University of Mainz, Duesbergweg 6, 55099 Mainz, Germany
| | - Mareike Bernau
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Walter Mier
- Department of Radiochemistry, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Henrik Oster
- Institute of Neurobiology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Olaf Jöhren
- Center of Brain, Behavior and Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Claus U Pietrzik
- Institute for Pathobiochemistry, University Medical Center, Johannes Gutenberg University of Mainz, Duesbergweg 6, 55099 Mainz, Germany
| | - Hendrik Lehnert
- Department of Internal Medicine, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany; Deutsches Zentrum für Diabetesforschung, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
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Jensen VFH, Mølck AM, Bøgh IB, Lykkesfeldt J. Effect of insulin-induced hypoglycaemia on the peripheral nervous system: focus on adaptive mechanisms, pathogenesis and histopathological changes. J Neuroendocrinol 2014; 26:482-96. [PMID: 24921897 DOI: 10.1111/jne.12170] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 05/22/2014] [Accepted: 06/05/2014] [Indexed: 12/31/2022]
Abstract
Insulin-induced hypoglycaemia (IIH) is a common acute side effect in type 1 and type 2 diabetic patients, especially during intensive insulin therapy. The peripheral nervous system (PNS) depends on glucose as its primary energy source during normoglycaemia and, consequently, it may be particularly susceptible to IIH damage. Possible mechanisms for adaption of the PNS to IIH include increased glucose uptake, utilisation of alternative energy substrates and the use of Schwann cell glycogen as a local glucose reserve. However, these potential adaptive mechanisms become insufficient when the hypoglycaemic state exceeds a certain level of severity and duration, resulting in a sensory-motor neuropathy with associated skeletal muscle atrophy. Large myelinated motor fibres appear to be particularly vulnerable. Thus, although the PNS is not an obligate glucose consumer, as is the brain, it appears to be more prone to IIH than the central nervous system when hypoglycaemia is not severe (blood glucose level ≤ 2 mm), possibly reflecting a preferential protection of the brain during periods of inadequate glucose availability. With a primary focus on evidence from experimental animal studies investigating nondiabetic IIH, the present review discusses the effect of IIH on the PNS with a focus on adaptive mechanisms, pathogenesis and histological changes.
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Affiliation(s)
- V F H Jensen
- Department of Veterinary Disease, Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Diabetes Toxicology and Safety Pharmacology, Novo Nordisk A/S, Maaloev, Denmark
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Suen WW, Prow NA, Hall RA, Bielefeldt-Ohmann H. Mechanism of West Nile virus neuroinvasion: a critical appraisal. Viruses 2014; 6:2796-825. [PMID: 25046180 PMCID: PMC4113794 DOI: 10.3390/v6072796] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 12/11/2022] Open
Abstract
West Nile virus (WNV) is an important emerging neurotropic virus, responsible for increasingly severe encephalitis outbreaks in humans and horses worldwide. However, the mechanism by which the virus gains entry to the brain (neuroinvasion) remains poorly understood. Hypotheses of hematogenous and transneural entry have been proposed for WNV neuroinvasion, which revolve mainly around the concepts of blood-brain barrier (BBB) disruption and retrograde axonal transport, respectively. However, an over‑representation of in vitro studies without adequate in vivo validation continues to obscure our understanding of the mechanism(s). Furthermore, WNV infection in the current rodent models does not generate a similar viremia and character of CNS infection, as seen in the common target hosts, humans and horses. These differences ultimately question the applicability of rodent models for pathogenesis investigations. Finally, the role of several barriers against CNS insults, such as the blood-cerebrospinal fluid (CSF), the CSF-brain and the blood-spinal cord barriers, remain largely unexplored, highlighting the infancy of this field. In this review, a systematic and critical appraisal of the current evidence relevant to the possible mechanism(s) of WNV neuroinvasion is conducted.
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Affiliation(s)
- Willy W Suen
- School of Veterinary Science, University of Queensland, Gatton, QLD, 4343, Australia.
| | - Natalie A Prow
- Australian Infectious Diseases Research Centre, University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Roy A Hall
- Australian Infectious Diseases Research Centre, University of Queensland, St. Lucia, QLD, 4072, Australia.
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Abstract
The blood-nerve barrier (BNB) separates the endoneurium from the endovascular space and the epineurial connective tissue. An intact BNB is very important for integrity and functions of the nerve fibers within the endoneurial space. Disruption of the BNB which leads to functional and structural impairment of the peripheral nerve plays an important role in many disorders of the peripheral nerve like Wallerian degeneration, inflammatory nerve disorders, and demyelination. So far, this increased BNB permeability can only be assessed ex vivo. Assessing BNB disruption in vivo would be of great value for studying disorders of the peripheral nervous system. Gadofluorine M (Gf), a new amphiphilic contrast agent for MRI, accumulates in rat nerves with increased permeability of the BNB. After application of Gf, T1-weighted MR images show contrast enhancement of nerves with a disrupted BNB. This new tool of assessing BNB permeability in vivo is described.
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Affiliation(s)
- Carsten Wessig
- Department of Neurology, University of Würzburg, Würzburg, Germany
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Zhao JP, Liu SW, Li YZ, Li XH, Zhang MN. [Characteristics of blood-optic nerve barrier: experiment with rats]. Zhonghua Yi Xue Za Zhi 2007; 87:999-1002. [PMID: 17650430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVE To investigate the difference of endothelial cells in ultrastructure, marker expression, and permeability between blood-brain barrier and blood-optic nerve barrier. METHODS The optic nerve, including the prelaminar region, lamina cribrosa, retro-laminar region, intraorbital portion, intracanalicular portion, and intracranial portion, and frontal cortex of 20 male SD rats were obtained to undergo electron microscopy and immunohistochemistry was used to detect the expression of endothelial barrier antigen (EBA) and the extravasation of fibrinogen around the microvessels. RESULTS Electron microscopy showed tight junction among the endothelial cells in the microvessels of all portions of optic nerve and cerebral cortex. The number of plasmalemmal vesicles of the prelaminar region was (108.0 +/- 12.0)/microm2, significantly greater than that of the cerebral cortex [(31.8 +/- 2.9)/microm2, P < 0.05]. However, there was no significantly difference in the number of plasmalemmal vesicle among the other portion of optic nerve and cerebral cortex (all P > 0.05). Immunohistochemistry showed that EBA was negative in the endothelial cells in the microvessels of prelaminar region, but strongly positive in the microvessels in the other portions of the optic nerve and in the cerebral cortex. Fibrinogen was present around the microvessels in the prelaminar region of optic nerve in a small amount, however, not present in the other portions of optic nerve and cerebral cortex. CONCLUSION There is significant differences in the number of plasmalemmal vesicle, EBA expression, and permeability between the prelaminar region of optic nerve and cerebral cortex, which demonstrates that this region lacks the characteristics of typical blood-brain barrier. However, the other parts of optic nerve possess the properties of classical blood-brain barrier.
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Affiliation(s)
- Jun-ping Zhao
- Institute of Medical Information, General Hospital of Chinese People's Liberation Army, Beijing 100853, China
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