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Yves Boucher - One of the best experts on this subject based on the ideXlab platform.
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could an endoneurial endothelial crosstalk between wnt β catenin and sonic hedgehog pathways underlie the early disruption of the infra orbital blood nerve Barrier following chronic constriction injury
Molecular Pain, 2017Co-Authors: Nathan Moreau, Annie Mauborgne, Pierre-olivier Couraud, Ignacio A Romero, Babette B Weksler, Luis Villanueva, Michel Pohl, Yves BoucherAbstract:Background: Blood-Nerve Barrier (BNB) disruption is pivotal in the development of neuroinflammation, peripheral sensitization and neuropathic pain after peripheral nerve injury (PNI). Activation of Toll-Like Receptor 4 (TLR4) and inactivation of Sonic Hedgehog (SHH) signaling pathways within the endoneurial endothelial cells (EEC) are key events, resulting in the infiltration of harmful molecules and immunocytes within the nerve parenchyma. However, preemptive inactivation of TLR4 signaling or sustained activation of SHH signaling do not prevent the local alterations observed following PNI, suggesting the implication of another signaling pathway. Methods: Using a classical neuropathic pain model, the infra-orbital nerve chronic constriction injury (IoN-CCI), and a neuritis model, the simple nerve stretch (SNS), we investigated the role of the Wnt/β-catenin pathway, its interactions with the TLR4 and SHH pathways and the phenotypical transition between neuritis and neuropathy. In PNI models (CCI and SNS) vs controls, mRNA expression levels and/or immunochemical detection of major readouts (Frizzled-7, VE-cadherin, Patched-1, Gli-1) and/or Tight Junction (TJ) proteins (Claudin 1,5, Occludin) were assessed. Vascular permeability (VP) was assessed by sodium fluorescein extravasation. Results: IoN-CCI induced early alterations in the VE-cadherin/β-catenin/Frizzled-7 complex, shown to participate in local BNB disruption via a β-catenin-dependent TJ protein downregulation. Wnt pathway also mediated a crosstalk between TLR4 and SHH signaling within EEC. Finally, differences in both the involvement of Wnt/β-catenin signaling and endoneural VP were observed between SNS and CCI, respectively mild reversible VP (mediated by Wnt/β-catenin signaling) vs irreversible VP (mediated by active Wnt/β-catenin and inactive SHH signaling). Such differential involvement of Wnt/β-catenin and SHH pathways might explain the transition between neuritis and neuropathy. Conclusion: A crosstalk between Wnt/β-catenin- and SHH-mediated signaling pathways within EEC mediates the chronic disruption of the BNB following PNI, resulting in increased irreversible endoneurial VP. Post-traumatic peripheral neuropathic pain could thus be considered a disease of VP.
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Could an endoneurial endothelial crosstalk between Wnt/β-catenin and Sonic Hedgehog pathways underlie the early disruption of the infraorbital blood–nerve Barrier following chronic constriction injury?
Molecular Pain, 2017Co-Authors: Nathan Moreau, Annie Mauborgne, Pierre-olivier Couraud, Ignacio A Romero, Babette B Weksler, Luis Villanueva, Michel Pohl, Yves BoucherAbstract:Background: Blood–nerve Barrier disruption is pivotal in the development of neuroinflammation, peripheral sensitization, and neuropathic pain after peripheral nerve injury. Activation of toll-like receptor 4 and inactivation of Sonic Hedgehog signaling pathways within the endoneurial endothelial cells are key events, resulting in the infiltration of harmful molecules and immunocytes within the nerve parenchyma. However, we showed in a previous study that preemptive inactivation of toll-like receptor 4 signaling or sustained activation of Sonic Hedgehog signaling did not prevent the local alterations observed following peripheral nerve injury, suggesting the implication of another signaling pathway. Methods: Using a classical neuropathic pain model, the infraorbital nerve chronic constriction injury (IoN-CCI), we investigated the role of the Wnt/β-catenin pathway in chronic constriction injury-mediated blood–nerve Barrier disruption and in its interactions with the toll-like receptor 4 and Sonic Hedgehog pathways. In the IoN-CCI model versus control, mRNA expression levels and/or immunochemical detection of major Wnt/Sonic Hedgehog pathway (Frizzled-7, vascular endothelial-cadherin, Patched-1 and Gli-1) and/or tight junction proteins (Claudin-1, Claudin-5, and Occludin) readouts were assessed. Vascular permeability was assessed by sodium fluorescein extravasation. Results: IoN-CCI induced early alterations in the vascular endothelial-cadherin/β-catenin/Frizzled-7 complex, shown to participate in local blood–nerve Barrier disruption via a β-catenin-dependent tight junction protein downregulation. Wnt pathway also mediated a crosstalk between toll-like receptor 4 and Sonic Hedgehog signaling within endoneurial endothelial cells. Nevertheless, preemptive inhibition of Wnt/β-catenin signaling before IoN-CCI could not prevent the downregulation of key Sonic Hedgehog pathway readouts or the disruption of the infraorbital blood–nerve Barrier, suggesting that Sonic Hedgehog pathway inhibition observed following IoN-CCI is an independent event responsible for blood–nerve Barrier disruption. Conclusion: A crosstalk between Wnt/β-catenin- and Sonic Hedgehog-mediated signaling pathways within endoneurial endothelial cells could mediate the chronic disruption of the blood–nerve Barrier following IoN-CCI, resulting in increased irreversible endoneurial vascular permeability and neuropathic pain development.
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early alterations of hedgehog signaling pathway in vascular endothelial cells after peripheral nerve injury elicit blood nerve Barrier disruption nerve inflammation and neuropathic pain development
Pain, 2016Co-Authors: Nathan Moreau, Annie Mauborgne, Pierre-olivier Couraud, Ignacio A Romero, Babette B Weksler, Luis Villanueva, Michel Pohl, S Bourgoin, Yves BoucherAbstract:Changes in the nerve's microenvironment and local inflammation resulting from peripheral nerve injury participate in nerve sensitization and neuropathic pain development. Taking part in these early changes, disruption of the Blood-Nerve Barrier (BNB) allows for infiltration of immunocytes and promotes the neuroinflammation. However, molecular mechanisms engaged in vascular endothelial cells (VEC) dysfunction and BNB alterations remain unclear. In vivo, BNB permeability was assessed following chronic constriction injury (CCI) of the rat sciatic nerve (ScN) and differential expression of markers of VEC functional state, inflammation, and intracellular signaling was followed from 3 hours to 2 months postinjury. Several mechanisms potentially involved in functional alterations of VEC were evaluated in vitro using human VEC (hCMEC/D3), then confronted to in vivo physiopathological conditions. CCI of the ScN led to a rapid disruption of endoneurial vascular Barrier that was correlated to a decreased production of endothelial tight-junction proteins and an early and sustained alteration of Hedgehog (Hh) signaling pathway. In vitro, activation of Toll-like receptor 4 in VEC downregulated the components of Hh pathway and altered the endothelial functional state. Inhibition of Hh signaling in the ScN of naive rats mimicked the biochemical and functional alterations observed after CCI and was, on its own, sufficient to evoke local neuroinflammation and sustained mechanical allodynia. Alteration of the Hh signaling pathway in VEC associated with peripheral nerve injury, is involved in BNB disruption and local inflammation, and could thus participate in the early changes leading to the peripheral nerve sensitization and, ultimately, neuropathic pain development.
Fumitaka Shimizu - One of the best experts on this subject based on the ideXlab platform.
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increased ip 10 production by blood nerve Barrier in multifocal acquired demyelinating sensory and motor neuropathy and multifocal motor neuropathy
Journal of Neurology Neurosurgery and Psychiatry, 2019Co-Authors: Fumitaka Shimizu, Toshihiko Maeda, Yukio Takeshita, Mariko Oishi, Setsu Sawai, Minako Beppu, Sonoko Misawa, Ai Miyashiro, Naoko Matsui, Hideaki NishiharaAbstract:Objective Dysfunction of the blood–nerve Barrier (BNB) plays important roles in chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). The aim of the present study was to identify the candidate cytokines/chemokines that cause the breakdown of the BNB using sera from patients with CIDP and MMN. Methods We determined the levels of 27 cytokines and chemokines in human peripheral nerve microvascular endothelial cells (PnMECs) after exposure to sera obtained from patients with CIDP variants (typical CIDP and multifocal acquired demyelinating sensory and motor neuropathy [MADSAM]), MMN and amyotrophic lateral sclerosis (ALS), and healthy controls (HC), using a multiplexed fluorescent bead-based immunoassay system. Results The induced protein (IP)10 level in the cells in both the MADSAM and MMN groups was markedly increased in comparison with the typical CIDP, ALS and HC groups. The other cytokines, including granulocyte colony-stimulating factor,vascular endothelial growth factor (VEGF) and interleukin-7, were also significantly upregulated in the MADSAM group. The increase of IP-10 produced by PnMECs was correlated with the presence of conduction block in both the MADSAM and MMN groups. Conclusion The autocrine secretion of IP-10 induced by patient sera in PnMECs was markedly upregulated in both the MADSAM and MMN groups. The overproduction of IP-10 by PnMECs leads to the focal breakdown of the BNB and may help to mediate the transfer of pathogenic T cells across the BNB, thereby resulting in the appearance of conduction block in electrophysiological studies of patients with MADSAM and MMN.
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establishment of a new conditionally immortalized human skeletal muscle microvascular endothelial cell line
Journal of Cellular Physiology, 2017Co-Authors: Hironori Sano, Yasuteru Sano, Fumitaka Shimizu, Toshihiko Maeda, Eri Ishiguchi, Masatoshi Omoto, Hideaki Nishihara, Yukio Takeshita, Shiori Takahashi, Mariko OishiAbstract:In skeletal muscle, the capillaries have tight junctions (TJs) that are structurally similar to those in the blood-brain Barrier (BBB) and Blood-Nerve Barrier (BNB). Although many findings have been clarified in the territory of BBB and BNB, few have so far examined the TJs of capillaries in the skeletal muscle. In addition, no in vitro human skeletal muscle microvasculature models have been reported thus far. We newly established a new human skeletal muscle microvascular endothelial cell (HSMMEC) line. HSMMECs were isolated from human skeletal muscle and were infected with retroviruses harboring temperature-sensitive SV40 T antigen and telomerase genes. This cell line, termed TSM15, showed a spindle fiber-shaped morphology, an immunoreactivity to anti-factor VIII and anti-VE-cadherin antibodies, and a temperature-sensitive growth. TSM15 cells grew stably for more than 40 passages when they were cultured at 33°C, thereby retaining their spindle fiber-shaped morphology and contact inhibition at confluence. The cells expressed tight junctional molecules such as claudin-5, occludin, and zonula occludens-1, as well as transporters such as a glucose transporter 1. The transendothelial electrical resistance of TSM15 was as high as those of the human brain microvascular endothelial cell line. This novel cell line might facilitate the analyses of the pathophysiology of inflammatory myopathy, such as dermatomyositis, and can improve our understanding of the physiological and biochemical properties of the microvasculature in human skeletal muscle.
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severity and patterns of blood nerve Barrier breakdown in patients with chronic inflammatory demyelinating polyradiculoneuropathy correlations with clinical subtypes
PLOS ONE, 2014Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Hideaki Nishihara, Setsu Sawai, Minako Beppu, Sonoko Misawa, Michiaki Koga, Satoshi Kuwabara, Takashi KandaAbstract:Objective Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is currently classified into clinical subtypes, including typical and atypical forms (multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) and distal acquired demyelinating symmetric neuropathy (DADS)). The aim of this study was to elucidate the patterns and severity of breakdown of the Blood-Nerve Barrier (BNB) in each CIDP subtype.
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sera from patients with multifocal motor neuropathy disrupt the blood nerve Barrier
Journal of Neurology Neurosurgery and Psychiatry, 2014Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Toshihiko Maeda, Masatoshi Omoto, Michiaki Koga, Naoko Mastui, Ai Miyashiro, Ayako Tasaki, Ryuji Kaji, Takashi KandaAbstract:Objective In multifocal motor neuropathy (MMN), the destruction of the Blood-Nerve Barrier (BNB) has been considered to be the key step in the disease process. The purpose of the present study was to ascertain whether sera from patients with MMN can open the BNB, and which component of patient sera is the most important for this disruption. Methods We evaluated the effects of sera from patients with MMN, patients with amyotrophic lateral sclerosis, and control subjects on the expression of tight junction proteins and vascular cell adhesion molecule-1 (VCAM-1), and on the transendothelial electrical resistance (TEER) in human peripheral nerve microvascular endothelial cells (PnMECs). Results The sera from patients with MMN decreased the claudin-5 protein expression and the TEER in PnMECs. However, this effect was reversed after application of an anti-vascular endothelial growth factor (anti-VEGF) neutralising antibody. The VEGF secreted by PnMECs was significantly increased after exposure to the sera from patients with MMN. The sera from patients with MMN also increased the VCAM-1 protein expression by upregulating the nuclear factor kappa-B (NF-κB) signalling. The immunoglobulin G purified from MMN sera decreased the expression of claudin-5 and increased the VCAM-1 expression in PnMECs. Conclusions The sera from MMN patients may disrupt the BNB function via the autocrine secretion of VEGF in PnMECs, or the exposure to autoantibodies against PnMECs that are contained in the MMN sera. Autoantibodies against PnMECs in MMN sera may activate the BNB by upregulating the VCAM-1 expression, thereby allowing for the entry of a large number of circulating inflammatory cells into the peripheral nervous system.
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effect of sera from bickerstaff brainstem encephalitis and miller fisher syndrome patients against human blood brain Barrier and blood nerve Barrier in vitro models p06 141
Neurology, 2012Co-Authors: Kazuyuki Saito, Yasuteru Sano, Fumitaka Shimizu, Toshihiko Maeda, Michiaki Koga, Ayako Tasaki, Hiroyo Haruki, Masa Aki Abe, Seiko Suzuki, Susumu KusunokiAbstract:Objective: Antibody against GQ1b is frequently detected in Bickerstaff brainstem encephalitis (BBE) and Miller Fisher syndrome (MFS) and has been considered to be pathogenically important in the development of these two disorders; however, the clinical manifestations of there two disorders are obviously different. We hypothesized that there phenotypic differences may be derived from the difference of blood-brain Barrier (BBB)/ Blood-Nerve Barrier(BNB) breakdown. Background We demonstrated the effects of sera from patients with BBE and MFS on the impairment of BBB or BNB function and clarified the roles of humoral factor such as Matrix metalloproteinases(MMP) in the destruction of BBB or BNB. Design/Methods: Both human BBB and BNB-derived endothelial cell lines were recently developed in Yamaguchi University, named TY10 and PnMECs. We evaluated transendothelial electrical resistance (TEER), the amount of tight junction proteins including claudin-5 and occludin, and the amount of MMP including MMP-9 and MMP-2 by western blotting in TY10 and PnMECs after the exposure of the patients9 sera. Results: The amount of claudin-5 protein in TY10, not in PnMECs, decreased after exposure of BBE sera. TEER of TY10 also decreased after application of BBE sera. Sera from MFS patients had no effect in these experiments. The amount of MMP-9 and MMP-2 protein in TY10 increased after exposure of BBE sera. Conclusions: Only sera from BBE patients disrupt BBB. This may partially explain the phenotypic defferences between BBE and MFS. BBE sera break BBB, possibly via autocrine secretion of MMP-9 and MMP-2 from BBB-composing endothelial cells. Disclosure: Dr. Saito has nothing to disclose. Dr. Shimizu has nothing to disclose. Dr. Koga has nothing to disclose. Dr. Sano has nothing to disclose. Dr. Haruki has nothing to disclose. Dr. Maeda has nothing to disclose. Dr. Abe has nothing to disclose. Dr. Tasaki has nothing to disclose. Dr. Suzuki has nothing to disclose. Dr. Kusunoki has nothing to disclose. Dr. Mizusawa has received personal compensation for activities with Tanabemitsubishi Co and Sanofi-Aventis Co. Dr. Mizusawa has received personal compensation in an editorial capacity for No to Shinkei and Clinical Neuroscience. Dr. Kanda has nothing to disclose.
Takashi Kanda - One of the best experts on this subject based on the ideXlab platform.
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severity and patterns of blood nerve Barrier breakdown in patients with chronic inflammatory demyelinating polyradiculoneuropathy correlations with clinical subtypes
PLOS ONE, 2014Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Hideaki Nishihara, Setsu Sawai, Minako Beppu, Sonoko Misawa, Michiaki Koga, Satoshi Kuwabara, Takashi KandaAbstract:Objective Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is currently classified into clinical subtypes, including typical and atypical forms (multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) and distal acquired demyelinating symmetric neuropathy (DADS)). The aim of this study was to elucidate the patterns and severity of breakdown of the Blood-Nerve Barrier (BNB) in each CIDP subtype.
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sera from patients with multifocal motor neuropathy disrupt the blood nerve Barrier
Journal of Neurology Neurosurgery and Psychiatry, 2014Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Toshihiko Maeda, Masatoshi Omoto, Michiaki Koga, Naoko Mastui, Ai Miyashiro, Ayako Tasaki, Ryuji Kaji, Takashi KandaAbstract:Objective In multifocal motor neuropathy (MMN), the destruction of the Blood-Nerve Barrier (BNB) has been considered to be the key step in the disease process. The purpose of the present study was to ascertain whether sera from patients with MMN can open the BNB, and which component of patient sera is the most important for this disruption. Methods We evaluated the effects of sera from patients with MMN, patients with amyotrophic lateral sclerosis, and control subjects on the expression of tight junction proteins and vascular cell adhesion molecule-1 (VCAM-1), and on the transendothelial electrical resistance (TEER) in human peripheral nerve microvascular endothelial cells (PnMECs). Results The sera from patients with MMN decreased the claudin-5 protein expression and the TEER in PnMECs. However, this effect was reversed after application of an anti-vascular endothelial growth factor (anti-VEGF) neutralising antibody. The VEGF secreted by PnMECs was significantly increased after exposure to the sera from patients with MMN. The sera from patients with MMN also increased the VCAM-1 protein expression by upregulating the nuclear factor kappa-B (NF-κB) signalling. The immunoglobulin G purified from MMN sera decreased the expression of claudin-5 and increased the VCAM-1 expression in PnMECs. Conclusions The sera from MMN patients may disrupt the BNB function via the autocrine secretion of VEGF in PnMECs, or the exposure to autoantibodies against PnMECs that are contained in the MMN sera. Autoantibodies against PnMECs in MMN sera may activate the BNB by upregulating the VCAM-1 expression, thereby allowing for the entry of a large number of circulating inflammatory cells into the peripheral nervous system.
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pericyte derived glial cell line derived neurotrophic factor increase the expression of claudin 5 in the blood brain Barrier and the blood nerve Barrier
Neurochemical Research, 2012Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Toshihiko Maeda, Hiroyo Haruki, Masa Aki Abe, Kazuyuki Saito, Takashi KandaAbstract:The destruction of blood–brain Barrier (BBB) and Blood-Nerve Barrier (BNB) has been considered to be a key step in the disease process of a number of neurological disorders including cerebral ischemia, Alzheimer’s disease, multiple sclerosis, and diabetic neuropathy. Although glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) facilitate neuronal or axonal regeneration in the brain or peripheral nerves, their action in the BBB and BNB remains unclear. The purpose of the present study was to elucidate whether these neurotrophic factors secreted from the brain or peripheral nerve pericytes increase the Barrier function of the BBB or BNB, using our newly established human brain microvascular endothelial cell (BMEC) line or peripheral nerve microvascular endothelial cell (PnMEC) line. GDNF increased the expression of claudin-5 and the transendothelial electrical resistance (TEER) of BMECs and PnMECs, whereas BDNF did not have this effect. Furthermore, we herein demonstrate that the GDNF secreted from the brain and peripheral nerve pericytes was one of the key molecules responsible for the up-regulation of claudin-5 expression and the TEER value in the BBB and BNB. These results indicate that the regulation of GDNF secreted from pericytes may therefore be a novel therapeutic strategy to modify the BBB or BNB functions and promote brain or peripheral nerve regeneration.
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advanced glycation end products induce basement membrane hypertrophy in endoneurial microvessels and disrupt the blood nerve Barrier by stimulating the release of tgf β and vascular endothelial growth factor vegf by pericytes
Diabetologia, 2011Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Hiroyo Haruki, Takashi KandaAbstract:Aims/hypothesis The breakdown of the blood–nerve Barrier (BNB) is considered to be a key step in diabetic neuropathy. Although basement membrane hypertrophy and breakdown of the BNB are characteristic features of diabetic neuropathy, the underlying pathogenesis remains unclear. The purpose of the present study was to identify the possible mechanisms responsible for inducing the hypertrophy of basement membrane and the disruption of the BNB after exposure to AGEs.
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peripheral nerve pericytes modify the blood nerve Barrier function and tight junctional molecules through the secretion of various soluble factors
Journal of Cellular Physiology, 2011Co-Authors: Fumitaka Shimizu, Yasuteru Sano, Toshihiko Maeda, Masa Aki Abe, Sumio Ohtsuki, Tetsuya Terasaki, Takashi KandaAbstract:The objectives of this study were to establish pure Blood-Nerve Barrier (BNB) and blood-brain Barrier (BBB)-derived pericyte cell lines of human origin and to investigate their unique properties as Barrier-forming cells. Brain and peripheral nerve pericyte cell lines were established via transfection with retrovirus vectors incorporating human temperature-sensitive SV40 T antigen (tsA58) and telomerase. These cell lines expressed several pericyte markers such as α-smooth muscle actin, NG2, platelet-derived growth factor receptor β, whereas they did not express endothelial cell markers such as vWF and PECAM. In addition, the inulin clearance was significantly lowered in peripheral nerve microvascular endothelial cells (PnMECs) through the up-regulation of claudin-5 by soluble factors released from brain or peripheral nerve pericytes. In particular, bFGF secreted from peripheral nerve pericytes strengthened the Barrier function of the BNB by increasing the expression of claudin-5. Peripheral nerve pericytes may regulate the Barrier function of the BNB, because the BNB does not contain cells equivalent to astrocytes which regulate the BBB function. Furthermore, these cell lines expressed several neurotrophic factors such as NGF, BDNF, and GDNF. The secretion of these growth factors from peripheral nerve pericytes might facilitate axonal regeneration in peripheral neuropathy. Investigation of the characteristics of peripheral nerve pericytes may provide novel strategies for modifying BNB functions and promoting peripheral nerve regeneration.
Nathan Moreau - One of the best experts on this subject based on the ideXlab platform.
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could an endoneurial endothelial crosstalk between wnt β catenin and sonic hedgehog pathways underlie the early disruption of the infra orbital blood nerve Barrier following chronic constriction injury
Molecular Pain, 2017Co-Authors: Nathan Moreau, Annie Mauborgne, Pierre-olivier Couraud, Ignacio A Romero, Babette B Weksler, Luis Villanueva, Michel Pohl, Yves BoucherAbstract:Background: Blood-Nerve Barrier (BNB) disruption is pivotal in the development of neuroinflammation, peripheral sensitization and neuropathic pain after peripheral nerve injury (PNI). Activation of Toll-Like Receptor 4 (TLR4) and inactivation of Sonic Hedgehog (SHH) signaling pathways within the endoneurial endothelial cells (EEC) are key events, resulting in the infiltration of harmful molecules and immunocytes within the nerve parenchyma. However, preemptive inactivation of TLR4 signaling or sustained activation of SHH signaling do not prevent the local alterations observed following PNI, suggesting the implication of another signaling pathway. Methods: Using a classical neuropathic pain model, the infra-orbital nerve chronic constriction injury (IoN-CCI), and a neuritis model, the simple nerve stretch (SNS), we investigated the role of the Wnt/β-catenin pathway, its interactions with the TLR4 and SHH pathways and the phenotypical transition between neuritis and neuropathy. In PNI models (CCI and SNS) vs controls, mRNA expression levels and/or immunochemical detection of major readouts (Frizzled-7, VE-cadherin, Patched-1, Gli-1) and/or Tight Junction (TJ) proteins (Claudin 1,5, Occludin) were assessed. Vascular permeability (VP) was assessed by sodium fluorescein extravasation. Results: IoN-CCI induced early alterations in the VE-cadherin/β-catenin/Frizzled-7 complex, shown to participate in local BNB disruption via a β-catenin-dependent TJ protein downregulation. Wnt pathway also mediated a crosstalk between TLR4 and SHH signaling within EEC. Finally, differences in both the involvement of Wnt/β-catenin signaling and endoneural VP were observed between SNS and CCI, respectively mild reversible VP (mediated by Wnt/β-catenin signaling) vs irreversible VP (mediated by active Wnt/β-catenin and inactive SHH signaling). Such differential involvement of Wnt/β-catenin and SHH pathways might explain the transition between neuritis and neuropathy. Conclusion: A crosstalk between Wnt/β-catenin- and SHH-mediated signaling pathways within EEC mediates the chronic disruption of the BNB following PNI, resulting in increased irreversible endoneurial VP. Post-traumatic peripheral neuropathic pain could thus be considered a disease of VP.
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Could an endoneurial endothelial crosstalk between Wnt/β-catenin and Sonic Hedgehog pathways underlie the early disruption of the infraorbital blood–nerve Barrier following chronic constriction injury?
Molecular Pain, 2017Co-Authors: Nathan Moreau, Annie Mauborgne, Pierre-olivier Couraud, Ignacio A Romero, Babette B Weksler, Luis Villanueva, Michel Pohl, Yves BoucherAbstract:Background: Blood–nerve Barrier disruption is pivotal in the development of neuroinflammation, peripheral sensitization, and neuropathic pain after peripheral nerve injury. Activation of toll-like receptor 4 and inactivation of Sonic Hedgehog signaling pathways within the endoneurial endothelial cells are key events, resulting in the infiltration of harmful molecules and immunocytes within the nerve parenchyma. However, we showed in a previous study that preemptive inactivation of toll-like receptor 4 signaling or sustained activation of Sonic Hedgehog signaling did not prevent the local alterations observed following peripheral nerve injury, suggesting the implication of another signaling pathway. Methods: Using a classical neuropathic pain model, the infraorbital nerve chronic constriction injury (IoN-CCI), we investigated the role of the Wnt/β-catenin pathway in chronic constriction injury-mediated blood–nerve Barrier disruption and in its interactions with the toll-like receptor 4 and Sonic Hedgehog pathways. In the IoN-CCI model versus control, mRNA expression levels and/or immunochemical detection of major Wnt/Sonic Hedgehog pathway (Frizzled-7, vascular endothelial-cadherin, Patched-1 and Gli-1) and/or tight junction proteins (Claudin-1, Claudin-5, and Occludin) readouts were assessed. Vascular permeability was assessed by sodium fluorescein extravasation. Results: IoN-CCI induced early alterations in the vascular endothelial-cadherin/β-catenin/Frizzled-7 complex, shown to participate in local blood–nerve Barrier disruption via a β-catenin-dependent tight junction protein downregulation. Wnt pathway also mediated a crosstalk between toll-like receptor 4 and Sonic Hedgehog signaling within endoneurial endothelial cells. Nevertheless, preemptive inhibition of Wnt/β-catenin signaling before IoN-CCI could not prevent the downregulation of key Sonic Hedgehog pathway readouts or the disruption of the infraorbital blood–nerve Barrier, suggesting that Sonic Hedgehog pathway inhibition observed following IoN-CCI is an independent event responsible for blood–nerve Barrier disruption. Conclusion: A crosstalk between Wnt/β-catenin- and Sonic Hedgehog-mediated signaling pathways within endoneurial endothelial cells could mediate the chronic disruption of the blood–nerve Barrier following IoN-CCI, resulting in increased irreversible endoneurial vascular permeability and neuropathic pain development.
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early alterations of hedgehog signaling pathway in vascular endothelial cells after peripheral nerve injury elicit blood nerve Barrier disruption nerve inflammation and neuropathic pain development
Pain, 2016Co-Authors: Nathan Moreau, Annie Mauborgne, Pierre-olivier Couraud, Ignacio A Romero, Babette B Weksler, Luis Villanueva, Michel Pohl, S Bourgoin, Yves BoucherAbstract:Changes in the nerve's microenvironment and local inflammation resulting from peripheral nerve injury participate in nerve sensitization and neuropathic pain development. Taking part in these early changes, disruption of the Blood-Nerve Barrier (BNB) allows for infiltration of immunocytes and promotes the neuroinflammation. However, molecular mechanisms engaged in vascular endothelial cells (VEC) dysfunction and BNB alterations remain unclear. In vivo, BNB permeability was assessed following chronic constriction injury (CCI) of the rat sciatic nerve (ScN) and differential expression of markers of VEC functional state, inflammation, and intracellular signaling was followed from 3 hours to 2 months postinjury. Several mechanisms potentially involved in functional alterations of VEC were evaluated in vitro using human VEC (hCMEC/D3), then confronted to in vivo physiopathological conditions. CCI of the ScN led to a rapid disruption of endoneurial vascular Barrier that was correlated to a decreased production of endothelial tight-junction proteins and an early and sustained alteration of Hedgehog (Hh) signaling pathway. In vitro, activation of Toll-like receptor 4 in VEC downregulated the components of Hh pathway and altered the endothelial functional state. Inhibition of Hh signaling in the ScN of naive rats mimicked the biochemical and functional alterations observed after CCI and was, on its own, sufficient to evoke local neuroinflammation and sustained mechanical allodynia. Alteration of the Hh signaling pathway in VEC associated with peripheral nerve injury, is involved in BNB disruption and local inflammation, and could thus participate in the early changes leading to the peripheral nerve sensitization and, ultimately, neuropathic pain development.
Ralf Gold - One of the best experts on this subject based on the ideXlab platform.
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anti inflammatory and immunomodulatory potential of human immunoglobulin applied intrathecally in lewis rat experimental autoimmune neuritis
Journal of Neuroimmunology, 2017Co-Authors: Kalliopi Pitarokoili, Xiomara Pedreiturria, Jeremias Motte, Felix Kohle, Oluwaseun Fatoba, Ralf Gold, Minsuk YoonAbstract:Abstract Intravenous human immunoglobulins dominate in the treatment of autoimmune neuropathies. We introduce intrathecal application as a new option for experimental autoimmune neuritis in Lewis rats. After immunisation with neuritogenic P2 peptide, we show a therapeutic and preventive effect of intrathecal human immunoglobulins (5–40 mg/kg) on clinical and electrophysiological neuritis signs. Histology corroborated a lower degree of inflammation, demyelination, ICAM-1-dependent Blood-Nerve-Barrier permeability and complement activation in the sciatic nerve. After preventive application, immunoglobulins induced a Th2 cytokine shift in the peripheral nerves already before clinical neuritis signs. Intrathecal immunoglobulin application could be a novel immunomodulatory option for autoimmune neuropathies.
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fingolimod attenuates experimental autoimmune neuritis and contributes to schwann cell mediated axonal protection
Journal of Neuroinflammation, 2017Co-Authors: Bjorn Ambrosius, Kalliopi Pitarokoili, Lisa Schrewe, Xiomara Pedreiturria, Jeremias Motte, Ralf GoldAbstract:Fingolimod, a sphingosine-1-phosphate receptor modulator with well-described immunomodulatory properties involving peripheral immune cell trafficking, was the first oral agent approved for the treatment of relapsing remitting multiple sclerosis. Analogous immunomodulatory treatment options for chronic peripheral autoimmune neuropathies are lacking. We tested fingolimod in the animal model of experimental autoimmune neuritis in Lewis rat. Six to eight-week-old female rats were immunized with P2 peptide and from this day on treated with fingolimod. Histology of the sciatic nerve was done to analyze T cell and macrophage cell count, intercellular adhesion molecule (ICAM) and amyloid precursor protein (APP) expression, as well as apoptotic Schwann cell counts. Preventive oral treatment with 0.1 mg/kg up to 3 mg/kg fingolimod once daily dissolved in rapeseed oil completely ameliorated clinical neuritis signs. It reduced circulating peripheral blood T cells and infiltrating T cells and macrophages in the sciatic nerve, whereas at the same time, it preserved Blood-Nerve Barrier impermeability. Most importantly, fingolimod showed beneficial properties on the pathogenic process as indicated by fewer apoptotic Schwann cells and a lower amount of amyloid precursor protein indicative of axonal damage at the peak of disease course. Taken together, orally administered low-dose fingolimod showed an impressive immunomodulatory effect in the rat model of experimental autoimmune neuritis. Our current observations introduce fingolimod as an attractive treatment option for neuritis patients.
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antiiflammatory and neuroprotective role of fingolimod in experimental autoimmune neuritis in lewis rats s28 007
Neurology, 2016Co-Authors: Bjorn Ambrosius, Kalliopi Pitarokoili, Lisa Schrewe, Ralf GoldAbstract:OBJECTIVE: We investigated the effect of fingolimod in experimental autoimmune neuritis (EAN), a rat model of acute autoimmune peripheral polyneuritis (Guillain-Barre Syndrome). BACKGROUND: Fingolimod is an orally administered, active immunomodulator with neuroprotective potential approved for the treatment of relapsing-remitting multiple sclerosis. Its mechanisms of action in the peripheral nerves have not been examined systematically yet however there are some reports regarding an influence on Schwann cells survival in vitro. METHODS: Active EAN was induced by immunization with the P2 aa 53-78 myelin peptide in Lewis rats followed by oral treatment with 1 to 3mg/kg Fingolimod diluted in rapeseed oil once daily from day 1 to 23 post-immunisation (p.i.), and clinical score was assessed daily. Electrophysiological analysis of demyelination as well as histological analyses of the sciatic nerves regarding demyelination, early axonal damage (amyloid precursor protein, APP), inflammatory infiltrates, Schwann cells survival (TUNEL) and ICAM1 (intracellular adhesion molecule 1) expression were performed at the disease maximum (day 16 p.i.). RESULTS: Preventive treatment with oral Fingolimod diluted in rapseed oil at all concentrations tested completely abolished clinical neuritis by reducing signs of demyelination in the nerve conduction studies. Histological analyses revealed a significantly lower degree of T cells and macrophages infiltrates in the sciatic nerves. In addition, we detected a reduction of early signs of axonal degeneration through a reduction of APP expressed in axons of the peripheral nerves. This reduction correlated with an increase of Schwann cells survival and a reduction of ICAM-1 expression at the disease maximum indicating the effects of fingolimod on Blood-Nerve Barrier permeability during inflammation. CONCLUSIONS: The effect on Blood-Nerve Barrier permeability and on Schwann cell survival in vivo represent new mechanisms of action of Fingolimod in peripheral neuritis and imply a crucial neuroprotective potential of this substance. Disclosure: Dr. Ambrosius has nothing to disclose. Dr. Pitarokoili has nothing to disclose. Dr. Schrewe has nothing to disclose. Dr. Gold has received research support from Bayer HealthCare, Biogen Idec, Merck Serono, Novartis, and Teva Neuroscience.
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immunmodulatory effects of intrathecal administration of human immunoglobulins in experimental autoimmune neuritis model in lewis rats p5 096
Neurology, 2016Co-Authors: Kalliopi Pitarokoili, Felix Kohle, Ralf Gold, Minsuk YoonAbstract:Objective:We studied the immunmodulatory effects of human immunoglobulins (Igs) applied intrathecally in the animal model of experimental autoimmune neuritis (EAN) in Lewis rats. Background:Therapeutic efficacy of intravenous human immunoglobulins in chronic and acute autoimmune neuritis has been shown in several randomized, placebo-controlled studies, although the exact mechanisms of action remain unclear. Intrathecal drug administration is an alternate route of delivery in order to bypass the Blood-Nerve Barrier and achieve a direct effect on the nerve roots. Methods:Active EAN was induced by immunization with the P2 aa 53-78 myelin peptide in Lewis rats followed by intrathecal application of 10 mg/kg, 20 mg/kg or 40 mg/kg Igs once daily on days 0, 2 and 4 p.i (post-immunisation). The clinical severity score was assessed daily until day 23 p.i.. Nerve conduction studies and histological analyses of the sciatic nerves for demyelination and inflammatory infiltrates as well as flow cytometric analyses of the peripheral lymph nodes and spleen were performed at the disease maximum (day 16 p.i.). Results:Preventive treatment with 10mg/kg Igs applied intrathecally on days 0, 2 and 4 p.i. significantly ameliorated clinical signs of neuritis by reducing proximal as well as distal demyelination in the nerve conduction studies. Intrathecal injected Igs were detected with a specific anti-human Fc-IgG antibody in the proximal roots of EAN rats on day 16 p.i.. Further, histological analyses revealed a significantly lower degree of T cells and macrophages infiltrates accompanied with an increase of proinflammatory cytokines such as IL-10 in the sciatic nerves at the disease maximum. Conclusions: Intrathecal administration of human immunoglobulins in the rat model of autoimmune neuritis is a safe and effective immunmodulatory option. Further studies are required in order to investigate the safety and efficacy of intrathecal Ig application in patients with autoimmune neuritis. Study sponsored by: CSL Behring Disclosure: Dr. Pitarokoili has nothing to disclose. Dr. Kohle has nothing to disclose. Dr. Gold has received research support from Bayer HealthCare, Biogen Idec, Merck Serono, Novartis, and Teva Neuroscience. Dr. Yoon has received personal compensation for activities with CSL Behring as a speaker.
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accumulation of immunoglobulin across the blood nerve Barrier in spinal roots in adoptive transfer experimental autoimmune neuritis
Neuropathology and Applied Neurobiology, 2002Co-Authors: R D M Hadden, Ralf Gold, Kenneth Smith, N A Gregson, R A C HughesAbstract:: At the onset of Guillain-Barre syndrome, disruption of diffusion Barriers, such as the Blood-Nerve Barrier, probably increases the exposure of spinal roots and peripheral nerves to macromolecules, some of which might be pathogenic. As a measure of such disruption, we measured the accumulation in the endoneurium of spinal roots and sciatic nerve of systemically administered 125I-labelled immunoglobulin in adoptive transfer experimental autoimmune neuritis (AT-EAN) in the rat. AT-EAN is a model of Guillain-Barre syndrome, induced by injection of activated T lymphocytes sensitized to myelin P2 protein. Immunoglobulin accumulation was expressed as counts/min/mg in fixative-perfused roots as a percentage of that in serum, measured 24 h after intraperitoneal injection of 0.1 micro Ci 125I-labelled immunoglobulin. Immunoglobulin accumulation in the roots of normal rats was 3 +/- 1% (mean +/- SE), but this first increased 3(1/2) days after cell injection, peaked at 22 +/- 2% on day 4(1/2), and declined to normal by day 8. T lymphocytes and polymorphonuclear leucocytes first appeared within the endoneurium at day 3(1/2), and macrophages and a few erythrocytes at day 4. Neurological deficit appeared on day 4 and was maximal on day 6. Demyelination and axonal degeneration began at day 5. The first abnormality detected in AT-EAN was a rapid increase in the passage of immunoglobulin into spinal roots, together with endoneurial infiltration of T lymphocytes and polymorphonuclear leucocytes. Accumulation of immunoglobulin was maximal during the worsening of neurological deficit, and declined rapidly before the onset of neurological recovery.