Galectin-1 suppresses methamphetamine induced neuroinflammation in human brain microvascular endothelial cells: Neuroprotective role in maintaining blood brain barrier integrity

Role of Microglia in Psychostimulant Addiction

The use of psychostimulant drugs can modify brain function by inducing changes in the reward system, mainly due to alterations in dopaminergic and glutamatergic transmissions in the mesocorticolimbic pathway. However, the etiopathogenesis of addiction is a much more complex process. Previous data have suggested that microglia and other immune cells are involved in events associated with neuroplasticity and memory, which are phenomena that also occur in addiction. Nevertheless, how dependent is the development of addiction on the activity of these cells? Although the mechanisms are not known, some pathways may be involved. Recent data have shown psychoactive substances may act directly on immune cells, alter their functions and induce various inflammatory mediators that modulate synaptic activity. These could, in turn, be involved in the pathological alterations that occur in substance use disorder. Here, we extensively review the studies demonstrating how cocaine and amphetamines modulate microglial number, morphology, and function. We also describe the effect of these substances in the production of inflammatory mediators and a possible involvement of some molecular signaling pathways, such as the toll-like receptor 4. Although the literature in this field is scarce, this review compiles the knowledge on the neuroimmune axis that is involved in the pathogenesis of addiction, and suggests some pharmacological targets for the development of pharmacotherapy.

Neuroprotective Effect of Exogenous Galectin-1 in Status Epilepticus

Intrahippocampal pilocarpine microinjection (H-PILO) induces status epilepticus (SE) that can lead to spontaneous recurrent seizures (SRS) and neurodegeneration in rodents. Studies using animal models have indicated that lectins mediate a variety of biological activities with neuronal benefits, especially galectin-1 (GAL-1), which has been identified as an effective neuroprotective compound. GAL-1 is associated with the regulation of cell adhesion, proliferation, programmed cell death, and immune responses, as well as attenuating neuroinflammation. Here, we administrated GAL-1 to Wistar rats and evaluated the severity of the SE, neurodegenerative and inflammatory patterns in the hippocampal formation. Administration of GAL-1 caused a reduction in the number of class 2 and 4 seizures, indicating a decrease in seizure severity. Furthermore, we observed a reduction in inflammation and neurodegeneration 24 h and 15 days after SE. Overall, these results suggest that GAL-1 has a neuroprotective effect in the early stage of epileptogenesis and provides new insights into the roles of exogenous lectins in temporal lobe epilepsy (TLE).

Methamphetamine Induces Systemic Inflammation and Anxiety: The Role of the Gut–Immune–Brain Axis

Methamphetamine (METH) is a highly addictive drug abused by millions of users worldwide, thus becoming a global health concern with limited management options. The inefficiency of existing treatment methods has driven research into understanding the mechanisms underlying METH-induced disorders and finding effective treatments. This study aims to understand the complex interactions of the gastrointestinal–immune–nervous systems following an acute METH dose administration as one of the potential underlying molecular mechanisms concentrating on the impact of METH abuse on gut permeability. Findings showed a decreased expression of tight junction proteins ZO-1 and EpCAm in intestinal tissue and the presence of FABP-1 in sera of METH treated mice suggests intestinal wall disruption. The increased presence of CD45+ immune cells in the intestinal wall further confirms gut wall inflammation/disruption. In the brain, the expression of inflammatory markers Ccl2, Cxcl1, IL-1β, TMEM119, and the presence of albumin were higher in METH mice compared to shams, suggesting METH-induced blood–brain barrier disruption. In the spleen, cellular and gene changes are also noted. In addition, mice treated with an acute dose of METH showed anxious behavior in dark and light, open field, and elevated maze tests compared to sham controls. The findings on METH-induced inflammation and anxiety may provide opportunities to develop effective treatments for METH addiction in the future.

Galectin-3 mediated risk of inflammation in stable schizophrenia, with only possible secondary consequences for cognition

BACKGROUND

Evidence suggests that cytokines cause immune disturbances, shape immunological sequelae later in life, and modulate the risk of schizophrenia (SC). Galectin-3 (Gal-3), a multifaceted molecule of the glycan family, is involved in the formation of the immunological synapse and modulates the signalling pathway and effector functions of T lymphocytes, which are major producers of cytokines. We have previously reported elevated serum Gal-3 levels in stable SC patients. However, Gal-3 as a link between cognitive functioning and inflammation has not yet been investigated in SC.

AIM

To investigate the relationship between serum Gal-3 levels and cognitive performance, serum cytokines, and white blood cell count in three-month stably treated SC patients.

METHODS

Twenty-seven patients with SC in remission and 18 healthy volunteers participated in this case-control and correlational study. Clinical assessment was performed using the Positive and Negative Syndrome Scale and the Montreal-Cognitive Assessment. The results of previously measured serum levels of Gal-3, interleukin (IL)-33, soluble suppression of tumorigenicity 2 (sST2), tumor necrosis factor-alpha (TNF-α), IL-6 and IL-17 were used for further statistical analyses, and IL-4, IL-23, IL-1β and transforming growth factor-beta (TGF-β) were now additionally measured with a sensitive enzyme-linked immunosorbent assay. The number of leukocytes in the blood and the percentage of neutrophils, lymphocytes, and monocytes were determined with a standardized routine measurement procedure (Sysmex Technology). Statistical analyses were performed using SPSS 20.0 software.

RESULTS

We found no correlation between serum Gal-3 levels and cognitive functioning in SC patients. A positive correlation was found between the levels of Gal-3 and TNF-α (r = 0.476; P = 0.012), Gal-3 and IL-23 (r = 0.417; P = 0.031), and Gal-3 and sST2 (r = 0.402; P = 0.038). The binary logistic model, which included all nine cytokines measured in this patient sample, indicated the particular role of Gal-3 and TGF-β in the duration of SC. In the stabilization phase of SC, we observed a moderate and negative correlation between serum Gal-3 levels and leukocytes (r = -0.449; P < 0.019). Additional linear regression analysis showed a positive correlation between Gal-3 expression and risperidone dose (F: 4.467; P < 0.045; r² = 0.396).

CONCLUSION

The combined activity of Gal-3 and proinflammatory cytokines, TGF-β downregulation and lower counts of leukocytes influence the SC duration. Gal-3 likely manifests indirect immunometabolic regulation of cognition in SC.

HIV-1 and methamphetamine alter galectins -1, -3, and -9 in human monocyte-derived macrophages

Macrophages are key elements of the innate immune system. Their HIV-1 infection is a complex process that involves multiple interacting factors and various steps and is further altered by exposure of infected cells to methamphetamine (Meth), a common drug of abuse in people living with HIV. This is reflected by dynamic changes in the intracellular and secreted proteomes of these cells. Quantification of these changes poses a challenge for experimental design and associated analytics. In this study, we measured the effect of Meth on expression of intracellular and secreted galectins-1, -3, and -9 in HIV-1 infected human monocyte-derived macrophages (hMDM) using SWATH-MS, which was further followed by MRM targeted mass spectrometry validation. Cells were exposed to Meth either prior to or after infection. Our results are the first to perform comprehensive quantifications of galectins in primary hMDM cells during HIV-1 infection and Meth exposure a building foundation for future studies on the molecular mechanisms underlying cellular pathology of hMDM resulting from viral infection and a drug of abuse—Meth.

Mystery of methamphetamine-induced autophagosome accumulation in hippocampal neurons: loss of syntaxin 17 in defects of dynein-dynactin driving and autophagosome-late endosome/lysosome fusion

Methamphetamine (METH), a psychoactive-stimulant facilitates massive accumulation of autophagosomes and causes autophagy-associated neuronal death. However, the underlying mechanisms involving METH-induced auto-phagosome accumulation remain poorly understood. In the current study, autophagic flux was tracked by mRFP-GFP-LC3 adenovirus, 900 μM METH treatment was found to significantly disrupt autophagic flux, which was further validated by remarkable increase of co-localized of LC3 and SQSTM1/p62, enhancement of LC3-II and SQSTM1/p62 protein levels, and massive autophagosome puncta aggregation. With the cycloheximide (CHX) treatment, METH treatment was displayed a significant inhibition of SQSTM1/p62 degradation. Therefore, the mRNAs associated with vesicle degradation were screened, and syntaxin 17 (Stx17) and dynein-dynactin mRNA levels significantly decreased, an effect was proved in protein level as well. Intriguingly, METH induced autophagosome accumulation and autophagic flux disturbance was incredibly retarded by overexpression of Stx17, which was validated by the restoration of the fusion autophagosome-late endosome/lysosome fusion. Moreover, Stx17 overexpression obviously impeded the METH-induced decrease of co-localization of the retrograded motor protein dynein/dynactin and autophagosome-late endosome, though the dynein/dynactin proteins were not involved in autophagosome-late endosome/lysosome fusion. Collectively, our findings unravel the mechanism of METH-induced autophagosome accumulation involving autophagosome-late endosome/lysosome fusion deficiency and that autophagy-enhancing mechanisms such as the overexpression of Stx17 may be therapeutic strategies for the treatment of METH-induced neuronal damage.

Lactose-appended β-cyclodextrin as an effective nanocarrier for brain delivery

The blood-brain barrier (BBB) prevents the permeability of drugs into the brain, and as such limits the management of various brain diseases. To overcome this barrier, drug-encapsulating nanoparticles or vesicles, drug conjugates, and other types of drug delivery systems (DDSs) have been developed. However, the brain-targeting ability of nanoparticles or vesicles is still insufficient. Recently, among the various brain-targeting ligands previously studied for facilitating transcellular BBB transport, several sugar-appended nanocarriers for brain delivery were identified. Meanwhile, cyclodextrins (CyDs) have been used as nanocarriers for drug delivery since they can encapsulate hydrophobic compounds with high biocompatibility. Therefore, in this study, we created various sugar-appended β-cyclodextrins (β-CyDs) to discover novel brain-targeting ligands. As a result, of the six sugar-appended CyDs, lactose-appended β-CyD (Lac-β-CyD) showed greater cellular uptake in hCMEC/D3 cells, human brain microvascular endothelial cells, than other sugar-appended β-CyDs did. In addition, the permeability of Lac-β-CyD within the in vitro human BBB model was greater than that of other sugar-appended β-CyDs. Moreover, Lac-β-CyD significantly accumulated in the mouse brain after intravenous administration. Thus, Lac-β-CyD efficiently facilitated the accumulation of the model drug into the mouse brain. These findings suggest that Lac-β-CyD has the potential to be a novel carrier for drugs across the BBB.

The role of cldnh during the early retinal development in zebrafish

Claudin-3, an integral component of tight junction, has recently been shown to be expressed in retinal ganglion cells, retinal pigment cells, and retinal vascular endothelial cells. However, the role of claudin-3 in the development of the neural retina and its vessels remains undefined. This study aimed to investigate the role of zebrafish claudin-h (cldnh), the closest ortholog of mouse and human claudin-3, in the development of the neural retina and its vessels. Cldnh levels in green fluorescent protein transgenic zebrafish were genetically manipulated by cldnh morpholino oligonucleotide (MO) and cldnh mRNA to investigate gene function. The expression of cldnh was analyzed using polymerase chain reaction and immunofluorescence staining. The altered morphological, cellular and molecular events in the cldnh MO-morphant eyes were detected using hematoxylin-eosin staining, fluorescent dye injection, confocal in vivo imaging, BrdU labeling, TUNEL assay, RNA sequencing, and Western blot. We demonstrated that the cldnh protein was expressed in the neural retina and the hyaloid vessel which is the predecessor of the retinal vessel in zebrafish. Cldnh knockdown delayed lamination of the neural retina and reduced its thickness, which might be associated with the downregulation of the retinal development-related genes of atoh7, pcdh17, crx, neurod1, insm1a, sox9b and cdh11, and the upregulation of the cell cycle and apoptosis-associated genes of tp53, cdkn1a and casp8. Cldnh knockdown also reduced the density and interrupted the lumenization of the hyaloid vessels, which might be owing to the downregulation of the vessel formation-related genes of hlx1 and myl7. In conclusion, cldnh was required for the normal development of the neural retina and its vessels in zebrafish, providing a basis for elucidating its role in the pathogenesis of retinal vascular or inflammatory diseases.

Galectin-1 attenuates neurodegeneration in Parkinson's disease model by modulating microglial MAPK/IκB/NFκB axis through its carbohydrate-recognition domain

The vicious cycle between the chronicactivationofmicroglia and dopamine neurons degeneration is linked with the progression of Parkinson's disease (PD). Targeting microglialactivationhas proven to be a viable option to develop a disease-modified therapy for PD. Galectin-1, which has been reported to have an anti-neuroinflammation effect was used in the present study to evaluate its therapeutic effects on microglia activation and neuronal degeneration in Parkinson's disease model. It was found that galectin-1 attenuated the inflammatory insult and the apoptosis of SK-N-SH human neuroblastoma cells from conditioned medium of activated microglia induced by Lipopolysaccharides (LPS). Nonetheless, galectin-1 administration (0.5 mg/kg) inhibited the microglia activation, improved the motor deficits in PD mice model induced by MPTP (25 mg/kg weight of mouse, i.p.) and prevented the degeneration of dopaminergic neurons in the substantia nigra. Administration of galectin-1 resulted in p38 and ERK1/2 dephosphorylation followed by IκB/NFκB signaling pathway inhibition. Galectin-1 significantly decreased the secretion of pro-inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). The protective effects and modulation of the MAPK/IκB/NFκB signaling pathway were abolished with β-D-galactose which blocked the carbohydrate-recognition domain of galectin-1. The present study demonstrated that galectin-1 inhibited microglia activation and ameliorated neurodegenerative process in PD model by modulating MAPK/IκB/NFκB axis through its carbohydrate-recognition domain.

Differential Cellular Expression of Galectin-1 and Galectin-3 After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a devastating sub-type of stroke with no proven treatment. Given the emerging role of Galectin-1 and Galectin-3 in neuroimmune responses, the objective of the current manuscript is to elucidate hemorrhagic-injury induced modulation and cellular expression of Galectin-1 and Galectin-3 in the brain in a pre-clinical model of ICH. To address this, ICH was induced in male CD1 mice by collagenase injection method. Western blotting as well as Immunofluorescence staining was performed to characterize the temporal expression pattern as well as cellular localization of Galectin-1 and Galectin-3 after ICH. Further, genetic studies were conducted to assess the functional role of Galectin-1 and Galectin-3 in inflammatory response employing a murine macrophage cell line, RAW 264.7. Galectin-1 and Galectin-3 exhibited very profound and increased expression from day 3 to day 7-post-injury, in the perihematomal brain region after ICH in comparison to Sham. Further, Galectin-1 expression was mostly observed in GFAP-positive astrocytes whereas Galectin-3 expression was observed mostly in Iba1-positive microglia/macrophages as well as CD16/32 (M1 microglial/macrophage marker)-positive cells. Moreover, genetic studies revealed a negative regulatory role of both Galectin-1 and Galectin-3 in the release of a proinflammatory cytokine, IL-6 from RAW 264.7 cells depending on the stimulus. Altogether, the present manuscript demonstrates for the first time, increased expression as well as cellular localization of Galectin-1 and Galectin-3 in the perihematomal brain regions after ICH. In addition, the manuscript raises the potential of Galectin-1 and Galectin-3 in modulating glial responses and thereby brain injury after ICH, warranting further investigation.

Elevated cerebrospinal fluid Galectin-9 is associated with central nervous system immune activation and poor cognitive performance in older HIV-infected individuals

We previously reported that galectin-9 (Gal-9), a soluble lectin with immunomodulatory properties, is elevated in plasma during HIV infection and induces HIV transcription. The link between Gal-9 and compromised neuronal function is becoming increasingly evident; however, the association with neuroHIV remains unknown. We measured Gal-9 levels by ELISA in cerebrospinal fluid (CSF) and plasma of 70 HIV-infected (HIV+) adults stratified by age (older > 40 years and younger < 40 years) either ART suppressed or with detectable CSF HIV RNA, including a subgroup with cognitive assessments, and 18 HIV uninfected (HIV-) controls. Gal-9 tissue expression was compared in necropsy brain specimens from HIV- and HIV+ donors using gene datasets and immunohistochemistry. Among older HIV+ adults, CSF Gal-9 was elevated in the ART suppressed and CSF viremic groups compared to controls, whereas in the younger group, Gal-9 levels were elevated only in the CSF viremic group (p < 0.05). CSF Gal-9 positively correlated with age in all groups (p < 0.05). CSF Gal-9 tracked with CSF HIV RNA irrespective of age (β = 0.33; p < 0.05). Higher CSF Gal-9 in the older viremic HIV+ group correlated with worse neuropsychological test performance scores independently of age and CSF HIV RNA (p < 0.05). Furthermore, CSF Gal-9 directly correlated with myeloid activation (CSF-soluble CD163 and neopterin) in both HIV+ older groups (p < 0.05). Among HIV+ necropsy specimens, Gal-9 expression was increased in select brain regions compared to controls (p < 0.05). Gal-9 may serve as a novel neuroimmuno-modulatory protein that is involved in driving cognitive deficits in those aging with HIV and may be valuable in tracking cognitive abnormalities.

Effect of methamphetamine on the fasting blood glucose in methamphetamine abusers

Methamphetamine is a popular psychostimulant worldwide which causes neurotoxicity and neuroinflammation. Although previous studies have characterized potential associations between addictive drugs and fasting blood glucose, the influence of methamphetamine on the blood glucose is still largely unknown. The present study was designed to investigate the change of fasting blood glucose of methamphetamine abusers and to confirm the impairment of liver and kidney. Fasting blood glucose was significantly decreased in methamphetamine abusers and in a high-fat diet mouse model with methamphetamine treatment discontinuation. Serum level of ALT, creatine kinase and creatinine were increased in methamphetamine abusers. Serum level of ALT and AST were increased in a high-fat diet mouse model after methamphetamine injection, but there was no significant difference in the anatomy of the liver and kidney in high-fat diet treated mice with or without methamphetamine. The levels of ALT and creatinine were also increased in the methamphetamine abusers. This study demonstrated that the level of glucose was decreased in methamphetamine abusers and in high-fat diet-fed mice after methamphetamine treatment discontinuation. The effect of methamphetamine on the levels of blood glucose may provide the evidence that methamphetamine abusers should be keep energy balance due to the low blood glucose.

A potential impact of Helicobacter pylori-related galectin-3 in neurodegeneration

Neurodegeneration represents a component of the central nervous system (CNS) diseases pathogenesis, either as a disability primary source in the frame of prototype neurodegenerative disorders, or as a secondary effect, following inflammation, hypoxia or neurotoxicity. Galectins are members of the lectin superfamily, a group of endogenous glycan-binding proteins, able to interact with glycosylated receptors expressed by several immune cell types. Glycan-lectin interactions play critical roles in the living systems by involving and mediating a variety of biologically important normal and pathological processes, including cell-cell signaling shaping cell communication, proliferation and migration, immune responses and fertilization, host-pathogen interactions and diseases such as neurodegenerative disorders and tumors. This review focuses in the role of Galectin-3 in shaping responses of the immune system against microbial agents, and concretely, Helicobacter pylori (Hp), thereby potentiating effect of the microbe in areas distant from the ordinary site of colonization, like the CNS. We hereby postulate that gastrointestinal Hp alterations in terms of immune cell functional phenotype, cytokine and chemokine secretion, may trigger systemic responses, thereby conferring implications for remote processes susceptible in immunity disequilibrium, namely, the CNS inflammation and/or neurodegeneration.

Involvement of PUMA in pericyte migration induced by methamphetamine

Mounting evidence indicates that methamphetamine causes blood-brain barrier damage, with emphasis on endothelial cells. The role of pericytes in methamphetamine-induced BBB damage remains unknown. Our study demonstrated that methamphetamine increased the migration of pericytes from the endothelial basement membrane. However, the detailed mechanisms underlying this process remain poorly understood. Thus, we examined the molecular mechanisms involved in methamphetamine-induced pericyte migration. The results showed that exposure of C3H/10T1/2 cells and HBVPs to methamphetamine increased PUMA expression via activation of the sigma-1 receptor, MAPK and Akt/PI3K pathways. Moreover, methamphetamine treatment resulted in the increased migration of C3H/10T1/2 cells and HBVPs. Knockdown of PUMA in pericytes transduced with PUMA siRNA attenuated the methamphetamine-induced increase in cell migration through attenuation of integrin and tyrosine kinase mechanisms, implicating a role of PUMA in the migration of C3H/10T1/2 cells and HBVPs. This study has demonstrated that methamphetamine-mediated pericytes migration involves PUMA up-regulation. Thus, targeted studies of PUMA could provide insights to facilitate the development of a potential therapeutic approach for alleviation of methamphetamine-induced pericyte migration.

Extended-access methamphetamine self-administration elicits neuroinflammatory response along with blood-brain barrier breakdown

Methamphetamine (METH) is a highly addictive psychostimulant drug that can lead to neurological and psychiatric abnormalities. Several studies have explored the central impact of METH use, but the mechanism(s) underlying blood-brain barrier (BBB) dysfunction and associated neuroinflammatory processes after chronic METH consumption are still unclear. Important findings in the field are mainly based on in vitro approaches and animal studies using an acute METH paradigm, and not much is known about the neurovascular alterations under a chronic drug use. Thus, the present study aimed to fill this crucial gap by exploring the effect of METH-self administration on BBB function and neuroinflammatory responses. Herein, we observed an increase of BBB permeability characterized by Evans blue and albumin extravasation in the rat hippocampus and striatum triggered by extended-access METH self-administration followed by forced abstinence. Also, there was a clear structural alteration of blood vessels showed by the down-regulation of collagen IV staining, which is an important protein of the endothelial basement membrane, together with a decrease of intercellular junction protein levels, namely claudin-5, occludin and vascular endothelial-cadherin. Additionally, we observed an up-regulation of vascular cell and intercellular adhesion molecule, concomitant with the presence of T cell antigen CD4 and tissue macrophage marker CD169 in the brain parenchyma. Rats trained to self-administer METH also presented a neuroinflammatory profile characterized by microglial activation, astrogliosis and increased pro-inflammatory mediators, namely tumor necrosis factor-alpha, interleukine-1 beta, and matrix metalloproteinase-9. Overall, our data provide new insights into METH abuse consequences, with a special focus on neurovascular dysfunction and neuroinflammatory response, which may help to find novel approaches to prevent or diminish brain dysfunction triggered by this overwhelming illicit drug.

Immunomodulatory Factors Galectin-9 and Interferon-Gamma Synergize to Induce Expression of Rate-Limiting Enzymes of the Kynurenine Pathway in the Mouse Hippocampus

Elevated levels of circulating pro-inflammatory cytokines are associated with symptomology of several psychiatric disorders, notably major depressive disorder. Symptomology has been linked to inflammation/cytokine-dependent induction of the Kynurenine Pathway. Galectins, like pro-inflammatory cytokines, play a role in neuroinflammation and the pathogenesis of several neurological disorders but without a clearly defined mechanism of action. Their involvement in the Kynurenine Pathway has not been investigated. Thus, we searched for a link between galectins and the Kynurenine Pathway using in vivo and ex vivo models. Mice were administered LPS and pI:C to determine if galectins (Gal's) were upregulated in the brain following in vivo inflammatory challenges. We then used organotypic hippocampal slice cultures (OHSCs) to determine if Gal's, alone or with inflammatory mediators [interferon-gamma (IFNγ), tumor necrosis factor-alpha (TNFα), interleukin-1beta (IL-1β), polyinosine-polycytidylic acid (pI:C), and dexamethasone (Dex; synthetic glucocorticoid)], would increase expression of indoleamine/tryptophan-2,3-dioxygenases (DO's: Ido1, Ido2, and Tdo2; Kynurenine Pathway rate-limiting enzymes). In vivo, hippocampal expression of cytokines (IL-1β, TNFα, and IFNγ), Gal-3, and Gal-9 along with Ido1 and Ido2 were increased by LPS and pI:C (bacterial and viral mimetics). Of the cytokines induced in vivo, only IFNγ increased expression of two Ido1 transcripts (Ido1-FL and Ido1-v1) by OHSCs. Although ineffective alone, Gal-9 accentuated IFNγ-induced expression of only Ido1-FL. Similarly, IFNγ induced expression of several Ido2 transcripts (Ido2-v1, Ido2-v3, Ido2-v4, Ido2-v5, and Ido2-v6). Gal-9 accentuated IFNγ-induced expression of only Ido2-v1. Surprisingly, Gal-9 alone, slightly but significantly, induced expression of Tdo2 (Tdo2-v1 and Tdo2-v2, but not Tdo2-FL). These effects were specific to Gal-9 as Gal-1 and Gal-3 did not alter DO expression. These results are the first to show that brain Gal-9 is increased during LPS- and pI:C-induced neuroinflammation. Increased expression of Gal-9 may be critical for neuroinflammation-dependent induction of DO expression, either acting alone (Tdo2-v1 and Tdo2-v2) or to enhance IFNγ activity (Ido1-FL and Ido2-v1). Although these novel actions of Gal-9 are described for hippocampus, they have the potential to operate as DO-dependent immunomodulatory processes outside the brain. With the expanding implications of Kynurenine Pathway activation across multiple immune and psychiatric disorders, this synergy provides a new target for therapeutic development.

C5a induces caspase-dependent apoptosis in brain vascular endothelial cells in experimental lupus

Blood-brain barrier (BBB) dysfunction complicates central nervous system lupus, an important aspect of systemic lupus erythematosus. To gain insight into the underlying mechanism, vascular corrosion casts of brain were generated from the lupus mouse model, MRL/lpr mice and the MRL/MpJ congenic controls. Scanning electron microscopy of the casts showed loss of vascular endothelial cells in lupus mice compared with controls. Immunostaining revealed a significant increase in caspase 3 expression in the brain vascular endothelial cells, which suggests that apoptosis could be an important mechanism causing cell loss, and thereby loss of BBB integrity. Complement activation occurs in lupus resulting in increased generation of circulating C5a, which caused the endothelial layer to become 'leaky'. In this study, we show that C5a and lupus serum induced apoptosis in cultured human brain microvascular endothelial cells (HBMVECs), whereas selective C5a receptor 1 (C5aR1) antagonist reduced apoptosis in these cells, demonstrating C5a/C5aR1-dependence. Gene expression of initiator caspases, caspase 1 and caspase 8, and pro-apoptotic proteins death-associated protein kinase 1, Fas-associated protein (FADD), cell death-inducing DNA fragmentation factor 45 000 MW subunit A-like effector B (CIDEB) and BCL2-associated X protein were increased in HBMVECs treated with lupus serum or C5a, indicating that both the intrinsic and extrinsic apoptotic pathways could be critical mediators of brain endothelial cell apoptosis in this setting. Overall, our findings suggest that C5a/C5aR1 signalling induces apoptosis through activation of FADD, caspase 8/3 and CIDEB in brain endothelial cells in lupus. Further elucidation of the underlying apoptotic mechanisms mediating the reduced endothelial cell number is important in establishing the potential therapeutic effectiveness of C5aR1 inhibition that could prevent and/or reduce BBB alterations and preserve the physiological function of BBB in central nervous system lupus.

Methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxypyrovalerone (MDPV) induce differential cytotoxic effects in bovine brain microvessel endothelial cells

Designer drugs such as synthetic psychostimulants are indicative of a worldwide problem of drug abuse and addiction. In addition to methamphetamine (METH), these drugs include 3,4-methylenedioxy-methamphetamine (MDMA) and commercial preparations of synthetic cathinones including 3,4-methylenedioxypyrovalerone (MDPV), typically referred to as "bath salts." These psychostimulants exert neurotoxic effects by altering monoamine systems in the brain. Additionally, METH and MDMA adversely affect the integrity of the blood-brain barrier (BBB): there are no current reports on the effects of MDPV on the BBB. The aim of this study was to compare the effects of METH, MDMA and MDPV on bovine brain microvessel endothelial cells (bBMVECs), an accepted in vitro model of the BBB. Confluent bBMVEC monolayers were treated with METH, MDMA and MDPV (0.5mM-2.5mM) for 24h. METH and MDMA increased lactate dehydrogenase release only at the highest concentration (2.5mM), whereas MDPV induced cytotoxicity at all concentrations. MDMA and METH decreased cellular proliferation only at 2.5mM, with similar effects observed after MDPV exposures starting at 1mM. Only MDPV increased reactive oxygen species production at all concentrations tested whereas all 3 drugs increased nitric oxide production. Morphological analysis revealed different patterns of compound-induced cell damage. METH induced vacuole formation at 1mM and disruption of the monolayer at 2.5mM. MDMA induced disruption of the endothelial monolayer from 1mM without vacuolization. On the other hand, MDPV induced monolayer disruption at doses ≥0.5mM without vacuole formation; at 2.5mM, the few remaining cells lacked endothelial morphology. These data suggest that even though these synthetic psychostimulants alter monoaminergic systems, they each induce BBB toxicity by different mechanisms with MDPV being the most toxic.

WITHDRAWN: Melatonin improves methamphetamine-induced blood brain barrier impairment through NADPH oxidase-2 in primary rat brain microvascular endothelium cells

The Publisher regrets that this article is an accidental duplication of an article that has already been published in 〈BRES, 1646 (2016) 182-192〉, 10.1016/j.brainres.2016.05.049. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.