Proteomic interrogation of the meninges reveals the molecular identities of structural components and regional distinctions along the CNS axis.

The meninges surround the brain and spinal cord, affording physical protection while also serving as a niche of neuroimmune activity. Though possessing stromal qualities, its complex cellular and extracellular makeup has yet to be elaborated, and it remains unclear whether the meninges vary along the neuroaxis. Hence, studies were carried-out to elucidate the protein composition and structural organization of brain and spinal cord meninges in normal, adult Biozzi ABH mice. First, shotgun, bottom-up proteomics was carried-out. Prominent proteins at both brain and spinal levels included Type II collagen and Type II keratins, representing extracellular matrix (ECM) and cytoskeletal categories, respectively. While the vast majority of total proteins detected was shared between both meningeal locales, more were uniquely detected in brain than in spine. This pattern was also seen when total proteins were subdivided by cellular compartment, except in the case of the ECM category where brain and spinal meninges each had near equal number of unique proteins, and Type V and type III collagen registered exclusively in the spine. Quantitative analysis revealed differential expression of several collagens and cytoskeletal proteins between brain and spinal meninges. High-resolution immunofluorescence and immunogold-scanning electronmicroscopy on sections from whole brain and spinal cord - still encased within bone -identified major proteins detected by proteomics, and highlighted their association with cellular and extracellular elements of variously shaped arachnoid trabeculae. Western blotting aligned with the proteomic and immunohistological analyses, reinforcing differential appearance of proteins in brain vs spinal meninges. Results could reflect regional distinctions in meninges that govern protective and/or neuroimmune functions.

Bruton's tyrosine kinase inhibition reduces disease severity in a model of secondary progressive autoimmune demyelination.

Bruton's tyrosine kinase (BTK) is an emerging target in multiple sclerosis (MS). Alongside its role in B cell receptor signaling and B cell development, BTK regulates myeloid cell activation and inflammatory responses. Here we demonstrate efficacy of BTK inhibition in a model of secondary progressive autoimmune demyelination in Biozzi mice with experimental autoimmune encephalomyelitis (EAE). We show that late in the course of disease, EAE severity could not be reduced with a potent relapse inhibitor, FTY720 (fingolimod), indicating that disease was relapse-independent. During this same phase of disease, treatment with a BTK inhibitor reduced both EAE severity and demyelination compared to vehicle treatment. Compared to vehicle treatment, late therapeutic BTK inhibition resulted in fewer spinal cord-infiltrating myeloid cells, with lower expression of CD86, pro-IL-1ß, CD206, and Iba1, and higher expression of Arg1, in both tissue-resident and infiltrating myeloid cells, suggesting a less inflammatory myeloid cell milieu. These changes were accompanied by decreased spinal cord axonal damage. We show similar efficacy with two small molecule inhibitors, including a novel, highly selective, central nervous system-penetrant BTK inhibitor, GB7208. These results suggest that through lymphoid and myeloid cell regulation, BTK inhibition reduced neurodegeneration and disease progression during secondary progressive EAE.

Characterizing microglial gene expression in a model of secondary progressive multiple sclerosis.

Multiple sclerosis (MS) is the most common inflammatory, demyelinating and neurodegenerative disease of the central nervous system in young adults. Chronic-relapsing experimental autoimmune encephalomyelitis (crEAE) in Biozzi ABH mice is an experimental model of MS. This crEAE model is characterized by an acute phase with severe neurological disability, followed by remission of disease, relapse of neurological disease and remission that eventually results in a chronic progressive phase that mimics the secondary progressive phase (SPEAE) of MS. In both MS and SPEAE, the role of microglia is poorly defined. We used a crEAE model to characterize microglia in the different phases of crEAE phases using morphometric and RNA sequencing analyses. At the initial, acute inflammation phase, microglia acquired a pro-inflammatory phenotype. At the remission phase, expression of standard immune activation genes was decreased while expression of genes associated with lipid metabolism and tissue remodeling were increased. Chronic phase microglia partially regain inflammatory gene sets and increase expression of genes associated with proliferation. Together, the data presented here indicate that microglia obtain different features at different stages of crEAE and a particularly mixed phenotype in the chronic stage. Understanding the properties of microglia that are present at the chronic phase of EAE will help to understand the role of microglia in secondary progressive MS, to better aid the development of therapies for this phase of the disease.

Interleukin-17 affects synaptic plasticity and cognition in an experimental model of multiple sclerosis.

Cognitive impairment (CI) is a disabling concomitant of multiple sclerosis (MS) with a complex and controversial pathogenesis. The cytokine interleukin-17A (IL-17A) is involved in the immune pathogenesis of MS, but its possible effects on synaptic function and cognition are still largely unexplored. In this study, we show that the IL-17A receptor (IL-17RA) is highly expressed by hippocampal neurons in the CA1 area and that exposure to IL-17A dose-dependently disrupts hippocampal long-term potentiation (LTP) through the activation of its receptor and p38 mitogen-activated protein kinase (MAPK). During experimental autoimmune encephalomyelitis (EAE), IL-17A overexpression is paralleled by hippocampal LTP dysfunction. An in vivo behavioral analysis shows that visuo-spatial learning abilities are preserved when EAE is induced in mice lacking IL-17A. Overall, this study suggests a key role for the IL-17 axis in the neuro-immune cross-talk occurring in the hippocampal CA1 area and its potential involvement in synaptic dysfunction and MS-related CI.

Modeling compartmentalized chronic immune-mediated demyelinating CNS disease in the Biozzi ABH mouse.

We explored whether experimental autoimmune encephalomyelitis (EAE) in Biozzi mice recapitulates temporal dynamics of tissue injury, immune-pathogenesis and CNS compartmentalization occurring in progressive multiple sclerosis (MS). Chronic EAE exhibited relapsing and progressing disease, partial closure of BBB, reduced tissue inflammatory activity, and development of meningeal ectopic lymphoid tissue, directly opposing (potentially driving) spinal subpial demyelinated plaques. A T cell predominant disease during relapses transformed into a B cell predominant disease in late chronic EAE, with high serum anti-MOG reactivity. Thus, late chronic Biozzi EAE recapitulates essential features of progressive MS, and is suitable for developing disease modifying and regenerative therapies.

Unexpected additive effects of minocycline and hydroxychloroquine in models of multiple sclerosis: Prospective combination treatment for progressive disease?

BACKGROUND: Most multiple sclerosis (MS) patients succumb to a progressive phenotype. Continued lymphocyte activity in the brain, microglia-mediated injury, iron deposition, and oxidative stress are characteristics of progressive MS. OBJECTIVE: As minocycline and hydroxychloroquine have been shown to inhibit microglia, we evaluated their effects on other outcomes relevant for progression. METHODS: Medications were evaluated in culture and in mice with acute and chronic experimental autoimmune encephalomyelitis (EAE). RESULTS: Both medications individually reduced iron neurotoxicity and a combination effect was not observed. Hydroxyl radical scavenging activity was manifested by minocycline only. Minocycline reduced T-cell proliferation more prominently than hydroxychloroquine; an aggregate effect occurred at low but not high concentrations. B-cell proliferation was mitigated to a greater extent by hydroxychloroquine and an additive effect was not evident. In EAE, suboptimal doses of minocycline and hydroxychloroquine individually delayed onset of clinical signs, while their combination suppressed clinical manifestations until treatment was stopped. In Biozzi ABH mice, a model of progressive MS, the chronic phase was beneficially altered using the combination. CONCLUSION: While minocycline and hydroxychloroquine did not manifest additive effects in most culture assays, their combination at suboptimal doses in EAE unexpectedly exceeded their individual activity. Minocycline and hydroxychloroquine combined are candidate treatments for progressive MS.

Antidote to cannabinoid intoxication: the CB1 receptor inverse agonist, AM251, reverses hypothermic effects of the CB1 receptor agonist, CB-13, in mice.

BACKGROUND AND PURPOSE: Cannabis is a recreational drug leading to intoxication, following stimulation of cannabinoid CB1 receptors. However, more recently, herbs mixed with synthetic cannabinoids sometimes known as 'Spice' and 'Black Mamba' have been increasingly used, and their high CB1 receptor affinity has led not only to marked intoxication but also life-threatening complications and an increasing number of deaths. Although many studies have indicated that prophylactic treatment with CB1 receptor antagonists can block cannabimimetic effects in animals and humans, the aim of this study was to determine whether CB1 receptor antagonism could reverse physical cannabimimetic effects. EXPERIMENTAL APPROACH: Cannabimimetic effects, measured by the hypothermic response following sedation and hypomotility, were induced by the synthetic CB1 receptor agonist CB-13 (1-naphthalenyl[4-(pentyloxy)-1-naphthalenyl]methanone) in Biozzi Antibody High mice. The CB1 receptor antagonist/inverse agonist AM251 (N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide) was administered 20 min after the injection of CB-13 and its effects on the cannabimimetic responses were assessed. KEY RESULTS: In this study, the CNS-related cannabimimetic effects, as measured by the hypothermic effect, induced by the CB1 receptor agonist were therapeutically treated and were rapidly reversed by the CB1 receptor antagonist/inverse agonist. There was also a subjective reversal of visually evident sedation. CONCLUSIONS AND IMPLICATIONS: Cannabinoid receptor antagonists have been widely used and so may provide an acceptable single-dose antidote to cannabinoid intoxication. This use may save human life, where the life-threatening effects are mediated by cannabinoid receptors and not off-target influences of the synthetic cannabinoids or non-cannabinoids within the recreational drug mixture.

Depletion of CD52-positive cells inhibits the development of central nervous system autoimmune disease, but deletes an immune-tolerance promoting CD8 T-cell population. Implications for secondary autoimmunity of alemtuzumab in multiple sclerosis.

The objective was to determine whether CD52 lymphocyte depletion can act to promote immunological tolerance induction by way of intravenous antigen administration such that it could be used to either improve efficiency of multiple sclerosis (MS) inhibition or inhibit secondary autoimmunities that may occur following alemtuzumab use in MS. Relapsing experimental autoimmune encephalomyelitis was induced in ABH mice and immune cell depletion was therapeutically applied using mouse CD52 or CD4 (in conjunction with CD8 or CD20) depleting monoclonal antibodies. Immunological unresponsiveness was then subsequently induced using intravenous central nervous system antigens and responses were assessed clinically. A dose-response of CD4 monoclonal antibody depletion indicated that the 60-70% functional CD4 T-cell depletion achieved in perceived failed trials in MS was perhaps too low to even stop disease in animals. However, more marked (~75-90%) physical depletion of CD4 T cells by CD4 and CD52 depleting antibodies inhibited relapsing disease. Surprisingly, in contrast to CD4 depletion, CD52 depletion blocked robust immunological unresponsiveness through a mechanism involving CD8 T cells. Although efficacy was related to the level of CD4 T-cell depletion, the observations that CD52 depletion of CD19 B cells was less marked in lymphoid organs than in the blood provides a rationale for the rapid B-cell hyper-repopulation that occurs following alemtuzumab administration in MS. That B cells repopulate in the relative absence of T-cell regulatory mechanisms that promote immune tolerance may account for the secondary B-cell autoimmunities, which occur following alemtuzumab treatment of MS.

Characterisation of Transcriptional Changes in the Spinal Cord of the Progressive Experimental Autoimmune Encephalomyelitis Biozzi ABH Mouse Model by RNA Sequencing.

Multiple sclerosis (MS) is a debilitating immune-mediated neurological disorder affecting young adults. MS is primarily relapsing-remitting, but neurodegeneration and disability accumulate from disease onset. The most commonly used mouse MS models exhibit a monophasic immune response with fast accumulation of neurological damage that does not allow the study of progressive neurodegeneration. The chronic relapsing and secondary progressive EAE (pEAE) Biozzi ABH mouse model of MS exhibits a reproducible relapsing-remitting disease course that slowly accumulates permanent neurological deficit and develops a post-relapsing progressive disease that permits the study of demyelination and neurodegeneration. RNA sequencing (RNAseq) was used to explore global gene expression in the pEAE Biozzi ABH mouse. Spinal cord tissue RNA from pEAE Biozzi ABH mice and healthy age-matched controls was sequenced. 2,072 genes were differentially expressed (q<0.05) from which 1,397 were significantly upregulated and 675 were significantly downregulated. This hypothesis-free investigation characterised the genomic changes that describe the pEAE mouse model. The differentially expressed genes revealed a persistent immunoreactant phenotype, combined with downregulation of the cholesterol biosynthesis superpathway and the LXR/RXR activation pathway. Genes differentially expressed include the myelination genes Slc17a7, Ugt8A and Opalin, the neuroprotective genes Sprr1A, Osm and Wisp2, as well as genes identified as MS risk factors, including RGs14 and Scap2. Novel genes with unestablished roles in EAE or MS were also identified. The identification of differentially expressed novel genes and genes involved in MS pathology, opens the door to their functional study in the pEAE mouse model which recapitulates some of the important clinical features of progressive MS.

Pentraxin-3 is upregulated in the central nervous system during MS and EAE, but does not modulate experimental neurological disease.

Pentraxin-3 (PTX3), an acute-phase protein released during inflammation, aids phagocytic clearance of pathogens and apoptotic cells, and plays diverse immunoregulatory roles in tissue injury. In neuroinflammatory diseases, like MS, resident microglia could become activated by endogenous agonists for Toll like receptors (TLRs). Previously we showed a strong TLR2-mediated induction of PTX3 in cultured human microglia and macrophages by HspB5, which accumulates in glia during MS. Given the anti-inflammatory effects of HspB5, we examined the contribution of PTX3 to these effects in MS and its animal model EAE. Our data indicate that TLR engagement effectively induces PTX3 expression in human microglia, and that such expression is readily detectable in MS lesions. Enhanced PTX3 expression is prominently expressed in microglia in preactive MS lesions, and in microglia/macrophages engaged in myelin phagocytosis in actively demyelinating lesions. Yet, we did not detect PTX3 in cerebrospinal fluid of MS patients. PTX3 expression is also elevated in spinal cords during chronic relapsing EAE in Biozzi ABH mice, but the EAE severity and time course in PTX3-deficient mice did not differ from WT mice. Moreover, systemic PTX3 administration did not alter the disease onset or severity. Our findings reveal local functions of PTX3 during neuroinflammation in facilitating myelin phagocytosis, but do not point to a role for PTX3 in controlling the development of autoimmune neuroinflammation.

NMR-Based Metabolomics Separates the Distinct Stages of Disease in a Chronic Relapsing Model of Multiple Sclerosis.

Relapsing experimental allergic encephalomyelitis (Cr-EAE) is commonly used to explore the pathogenesis and efficacy of new therapies for MS, but it is unclear whether the metabolome of Cr-EAE is comparable to human multiple sclerosis (MS). For MS, the diagnosis and staging can be achieved by metabolomics on blood using a combination of magnetic resonance spectroscopy and partial least squares discriminant analysis (PLS-DA). Here, we sought to discover whether this approach could be used to differentiate between sequential disease states in Cr-EAE and whether the same metabolites would be discriminatory. Urine and plasma samples were obtained at different time-points from a clinically relevant model of MS. Using PLS-DA modelling for the urine samples furnished some predictive models, but could not discriminate between all disease states. However, PLS-DA modelling of the plasma samples was able to distinguish between animals with clinically silent disease (day 10, 28) and animals with active disease (day 14, 38). We were also able to distinguish Cr-EAE mice from naive mice at all-time points and control mice, treated with complete Freund's adjuvant alone, at day 14 and 38. Key metabolites that underpin these models included fatty acids, glucose and taurine. Two of these metabolites, fatty acids and glucose, were also key metabolites in separating relapsing-remitting MS from secondary-progressive MS in the human study. These results demonstrate the sensitivity of this metabolomics approach for distinguishing between different disease states. Furthermore, some, but not all, of the changes in metabolites were conserved in humans and the mouse model, which could be useful for future drug development.

Complement activation and expression during chronic relapsing experimental autoimmune encephalomyelitis in the Biozzi ABH mouse.

Chronic relapsing experimental autoimmune encephalomyelitis (crEAE) in mice recapitulates many of the clinical and histopathological features of human multiple sclerosis (MS), making it a preferred model for the disease. In both, adaptive immunity and anti-myelin T cells responses are thought to be important, while in MS a role for innate immunity and complement has emerged. Here we sought to test whether complement is activated in crEAE and important for disease. Disease was induced in Biozzi ABH mice that were terminated at different stages of the disease to assess complement activation and local complement expression in the central nervous system. Complement activation products were abundant in all spinal cord areas examined in acute disease during relapse and in the progressive phase, but were absent in early disease remission, despite significant residual clinical disease. Local expression of C1q and C3 was increased at all stages of disease, while C9 expression was increased only in acute disease; expression of the complement regulators CD55, complement receptor 1-related gene/protein y (Crry) and CD59a was reduced at all stages of the disease compared to naive controls. These data show that complement is activated in the central nervous system in the model and suggest that it is a suitable candidate for exploring whether anti-complement agents might be of benefit in MS.

Dynamics of sodium channel Nav1.5 expression in astrocytes in mouse models of multiple sclerosis.

Astrocytes actively participate in the response of the central nervous system to injury, including in multiple sclerosis. Astrocytes can play both beneficial and detrimental roles in response to neuroinflammation; however, in extreme cases, astrogliosis can result in the formation of a glial scar, which can impede the regeneration of injured neurons. Although astrocytes do not express the voltage-gated sodium channel Nav1.5 in the nonpathological human brain, they exhibit robust upregulation of Nav1.5 within acute and chronic multiple sclerosis lesions. Recent work has indicated that Nav1.5 contributes to the pathways that regulate glial scar formation in vitro through modulation of intracellular Ca levels. However, the temporal dynamics of astrocytic Nav1.5 channel expression in response to neuroinflammatory pathologies has not been investigated. We examined astrocytes from mice with monophasic and chronic-relapsing (CR) experimental autoimmune encephalomyelitis (EAE) by immunohistochemical analysis to determine whether Nav1.5 is expressed in these cells, and whether the expression correlates with the severity of disease and/or phases of relapse and remission. Our results demonstrate that Nav1.5 is upregulated in astrocytes in situ in a temporal manner that correlates with disease severity in both monophasic and CR EAE. Further, in CR EAE, Nav1.5 expression is upregulated during relapses and subsequently attenuated during periods of remission. These observations are consistent with the suggestion that Nav1.5 can play a role in the response of astrocytes to inflammatory pathologies in the central nervous system and suggest Nav1.5 may be a potential therapeutic target to modulate reactive astrogliosis in vivo.

A PTBA small molecule enhances recovery and reduces postinjury fibrosis after aristolochic acid-induced kidney injury.

Phenylthiobutanoic acids (PTBAs) are a new class of histone deacetylase (HDAC) inhibitors that accelerate recovery and reduce postinjury fibrosis after ischemia-reperfusion-induced acute kidney injury. However, unlike the more common scenario in which patients present with protracted and less clearly defined onset of renal injury, this model of acute kidney injury gives rise to a clearly defined injury that begins to resolve over a short period of time. In these studies, we show for the first time that treatment with the PTBA analog methyl-4-(phenylthio)butanoate (M4PTB) accelerates recovery and reduces postinjury fibrosis in a progressive model of acute kidney injury and renal fibrosis that occurs after aristolochic acid injection in mice. These effects are apparent when M4PTB treatment is delayed 4 days after the initiating injury and are associated with increased proliferation and decreased G2/M arrest of regenerating renal tubular epithelial cells. In addition, there is reduced peritubular macrophage infiltration and decreased expression of the macrophage chemokines CX3Cl1 and CCL2. Since macrophage infiltration plays a role in promoting kidney injury, and since renal tubular epithelial cells show defective repair and a marked increase in maladaptive G2/M arrest after aristolochic acid injury, these findings suggest M4PTB may be particularly beneficial in reducing injury and enhancing intrinsic cellular repair even when administered days after aristolochic acid ingestion.

Neurodegeneration progresses despite complete elimination of clinical relapses in a mouse model of multiple sclerosis.

BACKGROUND: [corrected] Multiple Sclerosis has two clinical phases reflecting distinct but inter-related pathological processes: focal inflammation drives the relapse-remitting stage and neurodegeneration represents the principal substrate of secondary progression. In contrast to the increasing number of effective anti-inflammatory disease modifying treatments for relapse-remitting disease, the absence of therapies for progressive disease represents a major unmet clinical need. This raises the unanswered question of whether elimination of clinical relapses will prevent subsequent progression and if so how early in the disease course should treatment be initiated. Experimental autoimmune encephalomyelitis in the Biozzi ABH mouse recapitulates the clinical and pathological features of multiple sclerosis including relapse-remitting episodes with inflammatory mediated demyelination and progressive disability with neurodegeneration. To address the relationship between inflammation and neurodegeneration we used an auto-immune tolerance strategy to eliminate clinical relapses in EAE in a manner analogous to the clinical effect of disease modifying treatments. RESULTS: By arresting clinical relapses in EAE at two distinct stages, early and late disease, we demonstrate that halting immune driven demyelination even after the first major clinical event is insufficient to prevent long-term neurodegeneration and associated gliosis. Nonetheless, early intervention is partially neuroprotective, whereas later interventions are not. Furthermore early tolerisation is also associated with increased remyelination. CONCLUSIONS: These findings are consistent with both a partial uncoupling of inflammation and neurodegeneration and that the regenerative response of remyelination is negatively correlated with inflammation. These findings strongly support the need for early combinatorial treatment of immunomodulatory therapies and neuroprotective treatments to prevent long-term neurodegeneration in multiple sclerosis.

Serum levels of 25-hydroxy vitamin D in normal Biozzi and C57BL/6 mice and during the course of chronic relapsing experimental autoimmune encephalomyelitis (CR EAE).

OBJECTIVE AND DESIGN: The aim of the study was to examine possible variations in the levels of 25-hydroxy vitamin D [25-(OH)D] in sera from normal Biozzi and C57BL/6 mice and during the course of chronic relapsing experimental autoimmune encephalomyelitis (CR EAE). MATERIAL: Serum concentrations of 25-(OH)D were measured in normal male and female Biozzi and C57BL/6 mice, at 3-4 weeks old and 8-10 weeks old, with a minimum of six animals/group. Levels of the vitamin were also determined in CR EAE-inoculated mice, and controls, during the course of the disease using a minimum of six animals/treatment. METHODS: Cardiac blood was collected from the groups of normal, control and CR EAE-sensitised mice and sera prepared, by centrifugation of clotted samples, and assayed for 25-(OH)D levels by chemiluminescence assay. RESULTS: Normal male and female Biozzi and C57BL/6 mice had significantly higher levels of 25-(OH)D at 8-10 weeks old compared to concentrations at 3-4 weeks of age (P < 0.005). Also, levels of the vitamin were significantly raised in C57BL/6 male and female mice compared to values in samples from corresponding Biozzi mice. In addition, the amounts of 25-(OH)D in sera from female Biozzi and C57BL/6 mice were significantly increased compared to strain and aged-matched male mice. The CR EAE mice with acute stage disease had significantly higher 25-(OH)D levels compared to controls (P < 0.005). Vitamin concentrations fell to within controls values with the progression of CR EAE. CONCLUSIONS: Our preliminary studies have revealed marked differences between the amounts of 25-(OH)D in sera from Biozzi and C57BL/6 mice together with clear gender bias. The investigations also show significant, but selective changes, in levels of the vitamin during the course of CR EAE that are not always associated with the neurological disease state.

Control of experimental spasticity by targeting the degradation of endocannabinoids using selective fatty acid amide hydrolase inhibitors.

BACKGROUND: It has been previously shown that CB1 cannabinoid receptor agonism using cannabis extracts alleviates spasticity in both a mouse experimental autoimmune encephalomyelitis (EAE) model and multiple sclerosis (MS) in humans. However, this action can be associated with dose-limiting side effects. OBJECTIVE: We hypothesised that blockade of anandamide (endocannabinoid) degradation would inhibit spasticity, whilst avoiding overt cannabimimetic effects. METHODS: Spasticity eventually developed following the induction of EAE in either wild-type or congenic fatty acid amide hydrolase (FAAH)-deficient Biozzi ABH mice. These animals were treated with a variety of different FAAH inhibitors and the effect on the degree of limb stiffness was assessed using a strain gauge. RESULTS: Control of spasticity was achieved using FAAH inhibitors CAY100400, CAY100402 and URB597, which was sustained following repeated administrations. Therapeutic activity occurred in the absence of overt cannabimimetic effects. Importantly, the therapeutic value of the target could be definitively validated as the treatment activity was lost in FAAH-deficient mice. Spasticity was also controlled by a selective monoacyl glycerol lipase inhibitor, JZL184. CONCLUSIONS: This study demonstrates definitively that FAAH inhibitors provide a new class of anti-spastic agents that may have utility in treating spasticity in MS and avoid the dose-limiting side effects associated with cannabis use.

Anti-IL-17A treatment reduces clinical score and VCAM-1 expression detected by in vivo magnetic resonance imaging in chronic relapsing EAE ABH mice.

IL-17 is argued to play an important role in the multiple sclerosis-like disease experimental autoimmune encephalitis (EAE). We investigated the therapeutic effects of anti-IL-17A in a chronic relapsing EAE ABH mouse model using conventional scoring, quantitative behavioral outcomes, and a novel vascular cell adhesion molecule 1 (VCAM-1)-targeted magnetic resonance imaging (MRI) contrast agent [anti-VCAM-microparticles of iron oxide (MPIO)] to identify conventionally undetectable neuropathology. Mice were administered prophylactic or treatment regimens of anti-IL-17A or IgG and two injections of anti-VCAM-MPIO before undergoing T2*-weighted three-dimensional and gadolinium-diethylenetriamine pentaacetic acid T1-weighted MRI. Rotarod, inverted screen, and open field motor function tests were performed, conventional clinical scores calculated, and central IL-17A mRNA expression quantified during acute disease, remission, and relapse. Prophylactic anti-IL-17A prevents acute disease and relapse and is associated with reduced clinical and functional severity. Treatment regimens delay relapse, improve functional scores, and are associated with reduced VCAM-MPIO lesions during remission. No significant alteration was detectable in levels of gadolinium-diethylenetriamine pentaacetic acid- or VCAM-MPIO-positive lesions during relapse. Prophylactic and treatment anti-IL-17A were therapeutically effective in chronic relapsing EAE, improving clinical and quantifiable functional outcomes. IL-17A expression seems significant during acute disease but less important chronically. Disease-related immunoneuropathology is more sensitively detected using VCAM-MPIO MRI, which may, therefore, be used to monitor therapy meaningfully.

Developmentally divergent effects of Rho-kinase inhibition on cocaine- and BDNF-induced behavioral plasticity.

Prefrontal cortical dendritic spine remodeling during adolescence may open a window of vulnerability to pathological stimuli that impact long-term behavioral outcomes, but causal mechanisms remain unclear. We administered the Rho-kinase inhibitor HA-1077 during three adolescent periods in mice to destabilize dendritic spines. In adulthood, cocaine-induced locomotor activity was exaggerated. By contrast, when administered in adulthood, HA-1077 had no psychomotor consequences and normalized food-reinforced instrumental responding after orbitofrontal-selective knockdown of Brain-derived neurotrophic factor, a potential factor in addiction. Thus, early-life Rho-kinase inhibition confers cocaine vulnerability, but may actually protect against pathological reward-seeking - particularly in cases of diminished neurotrophic support - in adulthood.

N-Methyl-D-aspartate (NMDA) receptor involvement in central nervous system prostaglandin production during the relapse phase of chronic relapsing experimental autoimmune encephalomyelitis (CR EAE).

Our previous studies have established that major changes in central nervous system (CNS) prostaglandin (PG) levels occur during the relapse phase of chronic relapsing experimental autoimmune encephalomyelitis (CR EAE), an animal model of the human demyelinating disease multiple sclerosis. PG production is controlled through a series of enzymic pathways that, in EAE, are influenced by neuroantigen-driven autoimmune events. In non-immune-based models of CNS disease, endogenous glucocorticoids have been proposed as instigators of PG synthesis via activation of the N-methyl-D-aspartate (NMDA) receptor. Glucocorticoids have an important regulatory role in the pathogenesis EAE and the NMDA receptor is intimately involved in many of the characteristic neuroinflammatory processes that govern the disease. Therefore, the alterations in prostanoid concentrations during the relapse stage of CR EAE may ultimately be governed by glucocorticoid-induced NMDA receptor activation. The current investigation has examined the proposed glucocorticoid-NMDA receptor link by determining the effects of the receptor antagonist, (+) MK-801, on CNS PGE 2 and PGD 2 levels in Biozzi mice with relapse symptoms of CR EAE. Prostanoid concentrations in the cerebral cortex were not altered by drug administration, and in cerebellar tissues, a vehicle effect negated any drug-induced changes. However, the level of PGD 2 in spinal cords from (+) MK-801-dosed mice was significantly lower, compared to controls, but PGE 2 concentrations remained unchanged. The results suggest that glucocorticoid-NMDA receptor-linked events are not primarily responsible for PG generation in the brain but may influence prostanoid production in discrete areas of the CNS.