Systematic screening of generic drugs for progressive multiple sclerosis identifies clomipramine as a promising therapeutic

Could antidepressants increase mood and immunity at the same time?

A review of scientific literature suggests that the use of antidepressants can be broadly extended to address various forms of stress and inflammation as an adjunctive therapy that enhances host resistance. While the effects of antidepressants on mood are well-documented in terms of their emotional, cognitive, and behavioral impacts, these aspects do not fully explain their cellular mechanisms of action. At the cellular level, antidepressants exert trophic effects that promote neurogenesis and synaptic connectivity. Studies demonstrate that antidepressants improve cell survival, enhance stem cell proliferation, and reduce danger perception (mood effects) in depressed patients and animal models of depression. These trophic properties highlight a deeper biological mechanism beyond their mood-related benefits. The acid sphingomyelinase (ASM) theory of mood offers a more compelling explanation of the cellular effects of antidepressants compared to the monoamine hypothesis. Antidepressants functionally inhibit the ASM enzyme, thereby reducing the production of ceramide, which directs cells toward increased survival, cytoprotection, and reproduction, as well as improved mood. This review also highlights research demonstrating that antidepressants enhance host resistance to infections, immunological challenges, stress, and depression. These findings support the potential use of antidepressants to bolster host resilience in scenarios involving infections, vaccinations, cellular aggression, stress, depression, and even aging.

Reactivity of Olanzapine and Tricyclic Antidepressants on the Protective Effects of Trolox on Lipid Peroxidation Evaluated Using Fluorescence Anisotropy, Electron Paramagnetic Resonance Spectrometry, and Thermal Analysis

Multiacting receptor-targeting antipsychotics and tricyclic antidepressants stimulate various neurotransmitter receptors despite the different targets of postsynaptic receptors and presynaptic reuptake transporters. Their auxiliary and adverse effects may be caused by multiple targets or the modification of the neuronal membrane. To evaluate the membrane responses to olanzapine, imipramine, desipramine, amitriptyline, lidocaine, and dibucaine, we examined the inhibition of lipid peroxidation in egg yolk phosphatidylcholine liposomes. By contrast, their effects on membrane fluidity were measured as the suppressive contributions of the inhibitory activity of Trolox on lipid oxidation. These drugs inhibit lipid peroxidation and exclude harmful reactive oxygen species and the protective effect of Trolox. The fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene in saturated phospholipid liposome-containing drugs suggested that olanzapine, imipramine, and dibucaine enhanced membrane fluidity. The radical scavenging activity of 2,2-diphenylpicrylhidrazyl and galvinoxyl radicals was determined using electron paramagnetic resonance experiments, and their molecular flexibility was determined using thermograms for differential scanning calorimetry. Multiple regression analyses of the linear free energy relationship approach and comparative investigations revealed that the membranous fluidity of the liposomes, independent of the radical scavenging activity of the drugs, induced the inhibitory activity on lipid peroxidation. We discussed how these drugs act on nervous membranes and aimed to identify the relationship between uncertified functions and membranous fluidity.

Pharmacogenomic screening identifies and repurposes leucovorin and dyclonine as pro-oligodendrogenic compounds in brain repair

Oligodendrocytes are critical for CNS myelin formation and are involved in preterm-birth brain injury (PBI) and multiple sclerosis (MS), both of which lack effective treatments. We present a pharmacogenomic approach that identifies compounds with potent pro-oligodendrogenic activity, selected through a scoring strategy (OligoScore) based on their modulation of oligodendrogenic and (re)myelination-related transcriptional programs. Through in vitro neural and oligodendrocyte progenitor cell (OPC) cultures, ex vivo cerebellar explants, and in vivo mouse models of PBI and MS, we identify FDA-approved leucovorin and dyclonine as promising candidates. In a neonatal chronic hypoxia mouse model mimicking PBI, both compounds promote neural progenitor cell proliferation and oligodendroglial fate acquisition, with leucovorin further enhancing differentiation. In an adult MS model of focal de/remyelination, they improve lesion repair by promoting OPC differentiation while preserving the OPC pool. Additionally, they shift microglia from a pro-inflammatory to a pro-regenerative profile and enhance myelin debris clearance. These findings support the repurposing of leucovorin and dyclonine for clinical trials targeting myelin disorders, offering potential therapeutic avenues for PBI and MS.

Clinical dimensions of people with co-occurring obsessive-compulsive and related disorders and multiple sclerosis: a scoping review protocol

INTRODUCTION

Multiple sclerosis (MS) is an immune-mediated demyelinating disease with a significant burden of neuropsychiatric sequelae. These symptoms, including depression and anxiety, are predictors of morbidity and mortality in people with MS. Despite a high prevalence of obsessive-compulsive disorder in MS, potentially shared pathophysiological mechanisms and overlap in possible treatments, no review has specifically examined the clinical dimensions of people with obsessive-compulsive and related disorders (OCRD) and MS. In this scoping review, we aim to map the available knowledge on the clinical dimensions of people with co-occurring OCRD and MS. Understanding the characteristics of this population in greater detail will inform more patient-centred care and create a framework for future studies.

METHODS AND ANALYSIS

We developed a search strategy to identify all articles that include people with co-occurring OCRD and MS. The search strategy (extending to the grey literature) was applied to MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science and ProQuest Dissertations & Theses. Records will undergo title and abstract screening by two independent reviewers. Articles meeting inclusion criteria based on title and abstract screening will go on to full-text review by the two independent reviewers. After reaching a consensus about articles for inclusion in the final review, data will be extracted using a standardised extraction form. The extracted data will include clinical characteristics of patients such as age, gender, medication use and severity of MS, among others.

ETHICS AND DISSEMINATION

This scoping review does not require research ethics approval. Results will be shared at national and/or international conferences, in a peer-reviewed journal publication, in a plain language summary and in a webinar for the general public.

Fluvoxamine inhibits Th1 and Th17 polarization and function by repressing glycolysis to attenuate autoimmune progression in type 1 diabetes

BACKGROUND

Fluvoxamine is one of the selective serotonin reuptake inhibitors (SSRIs) that are regarded as the first-line drugs to manage mental disorders. It has been also recognized with the potential to treat inflammatory diseases and viral infection. However, the effect of fluvoxamine on autoimmune diseases, particularly type 1 diabetes (T1D) and the related cellular and molecular mechanisms, are yet to be addressed.

METHOD

Herein in this report, we treated NOD mice with fluvoxamine for 2 weeks starting from 10-week of age to dissect the impact of fluvoxamine on the prevention of type 1 diabetes. We compared the differences of immune cells between 12-week-old control and fluvoxamine-treated mice by flow cytometry analysis. To study the mechanism involved, we extensively examined the characteristics of CD4+ T cells with fluvoxamine stimulation using RNA-seq analysis, real-time PCR, Western blot, and seahorse assay. Furthermore, we investigated the relevance of our data to human autoimmune diabetes.

RESULT

Fluvoxamine not only delayed T1D onset, but also decreased T1D incidence. Moreover, fluvoxamine-treated NOD mice showed significantly attenuated insulitis coupled with well-preserved β cell function, and decreased Th1 and Th17 cells in the peripheral blood, pancreatic lymph nodes (PLNs), and spleen. Mechanistic studies revealed that fluvoxamine downregulated glycolytic process by inhibiting phosphatidylinositol 3-kinase (PI3K)-AKT signaling, by which it restrained effector T (Teff) cell differentiation and production of proinflammatory cytokines.

CONCLUSION

Collectively, our study supports that fluvoxamine could be a viable therapeutic drug against autoimmunity in T1D setting.

Hydroxychloroquine: Key therapeutic advances and emerging nanotechnological landscape for cancer mitigation

Hydroxychloroquine (HCQ) is a unique class of medications that has been widely utilized for the treatment of cancer. HCQ plays a dichotomous role by inhibiting autophagy induced by the tumor microenvironment (TME). Preclinical studies support the use of HCQ for anti-cancer therapy, especially in combination with conventional anti-cancer treatments since they sensitize tumor cells to drugs, potentiating the therapeutic activity. However, clinical evidence has suggested poor outcomes for HCQ due to various obstacles, including non-specific distribution, low aqueous solubility and low bioavailability at target sites, transport across tissue barriers, and retinal toxicity. These issues are addressable via the integration of HCQ with nanotechnology to produce HCQ-conjugated nanomedicines. This review aims to discuss the pharmacodynamic, pharmacokinetic and antitumor properties of HCQ. Furthermore, the antitumor performance of the nanoformulated HCQ is also reviewed thoroughly, aiming to serve as a guide for the HCQ-based enhanced treatment of cancers. The nanoencapsulation or nanoconjugation of HCQ with nanoassemblies appears to be a promising method for reducing the toxicity and improving the antitumor efficacy of HCQ.

Microglia Transcriptional Profiling in Major Depressive Disorder Shows Inhibition of Cortical Gray Matter Microglia

BACKGROUND

Microglia have been implicated in the pathophysiology of major depressive disorder (MDD), but information on biological mechanisms is limited. Therefore, we investigated the gene expression profile of microglial cells in relation to neuronal regulators of microglia activity in well-characterized MDD and control autopsy brains.

METHODS

Pure, intact microglia were isolated at brain autopsy from occipital cortex gray matter (GM) and corpus callosum white matter of 13 donors with MDD and 10 age-matched control donors for RNA sequencing. Top differentially expressed genes were validated using immunohistochemistry staining. Because gene expression changes were only detected in GM microglia, neuronal regulators of microglia were investigated in cortical tissue and synaptosomes from the cortex by reverse transcriptase-quantitative polymerase chain reaction and Western blot.

RESULTS

Transcriptome analysis revealed 92 genes differentially expressed in microglia isolated from GM, but none in microglia from white matter in donors with MDD, compared with control donors. Of these, 81 genes were less abundantly expressed in GM in MDD, including CD163, MKI67, SPP1, CD14, FCGR1A/C, and C1QA/B/C. Accordingly, pathways related to effector mechanisms, such as the complement system and phagocytosis, were differentially regulated in GM microglia in MDD. Immunohistochemistry staining revealed significantly lower expression of CD163 protein in MDD. Whole tissue analysis showed an increase in CD200 (p = .0009) and CD47 (p = .068) messenger RNA, and CD47 protein was significantly elevated (p = .0396) in synaptic fractions of MDD cases.

CONCLUSIONS

Transcriptional profiling indicates an immune-suppressed microglial phenotype in MDD that is possibly caused by neuronal regulation.

Iron in multiple sclerosis - Neuropathology, immunology, and real-world considerations

Iron is an essential element involved in a multitude of bodily processes. It is tightly regulated, as elevated deposition in tissues is associated with diseases such as multiple sclerosis (MS). Iron accumulation in the central nervous system (CNS) of MS patients is linked to neurotoxicity through mechanisms including oxidative stress, glutamate excitotoxicity, misfolding of proteins, and ferroptosis. In the past decade, the combination of MRI and histopathology has enhanced our understanding of iron deposition in MS pathophysiology, including in the pro-inflammatory and neurotoxicity of iron-laden rims of chronic active lesions. In this regard, iron accumulation may not only have an impact on different CNS-resident cells but may also promote the innate and adaptive immune dysfunctions in MS. Although there are discordant results, most studies indicate lower levels of iron but higher amounts of the iron storage molecule ferritin in the circulation of people with MS. Considering the importance of iron, there is a need for evidence-guided recommendation for dietary intake in people living with MS. Potential novel therapeutic approaches include the regulation of iron levels using next generation iron chelators, as well as therapies to interfere with toxic consequences of iron overload including antioxidants in MS.

Efforts Towards Repurposing of Antioxidant Drugs and Active Compounds for Multiple Sclerosis Control

Multiple Sclerosis (MS) is a degenerative disorder of the central nervous system (CNS) with complicated etiology that has not been clearly analyzed until nowadays. Apart from anti-inflammatory, immune modulatory and symptomatic treatments, which are the main tools towards MS control, antioxidant molecules may be of interest. Oxidative stress is a key condition implicated in the disease progression. Reactive species production is associated with immune cell activation in the brain as well as in the periphery, accounting for demyelinating and axonal disruptive processes. This review refers to research articles, of the last decade. It describes biological evaluation of antioxidant drugs, and molecules with pharmaceutical interest, which are not designed for MS treatment, however they seem to have potency against MS. Their antioxidant effect is accompanied, in most of the cases, by anti-inflammatory, immune-modulatory and neuroprotective properties. Compounds with such characteristics are expected to be beneficial in the treatment of MS, alone or as complementary therapy, improving some clinical and mechanistic aspects of the disease. This review also summarizes some of the pathobiological characteristics of MS, as well as the role of oxidative stress and inflammation in the progression of neurodegeneration. It presents known drugs and bioactive compounds with antioxidant, and in many cases, pleiotropic activity that have been tested for their efficacy in MS progression or the experimentally induced MS. Antioxidants may offer reduction or prevention of the disease symptoms and progression. Thus, their results may, combined with already applied treatments, be beneficial for the development of new molecules or the repurposing of drugs and supplements that are used with other indication so far.

Drug repurposing of ilepcimide that ameliorates experimental autoimmune encephalomyelitis via restricting inflammatory response and oxidative stress

Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system (CNS) that remains incurable. Herein, we demonstrated that ilepcimide (Antiepilepsirine), an antiepileptic drug used for decades, protects mice from experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Our studies found that ilepcimide treatment effectively ameliorates demyelination, blood-brain barrier leakage and infiltration of CD4⁺ and CD8⁺ T cells in EAE mice. On the one hand, ilepcimide can inhibit dihydroorotate dehydrogenase (DHODH), an important therapeutic target for MS. Computer molecular docking, thermal shift and fluorescence quenching assay demonstrated the directly interaction between ilepcimide and DHODH. Accordingly, ilepcimide observably repressed T cell proliferation in mixed lymphocyte reaction (MLR) assay and concanavalin A (Con-A) model in a DHODH-dependent manner. On the other hand, ilepcimide exhibited neuroprotective effect possibly through activating NRF2 antioxidant pathway in mouse neural crest-derived Neuro2a cells. Collectively, our findings have revealed the therapeutic potential of ilepcimide in EAE mouse model via restricting inflammatory response and oxidative stress, offering a potential opportunity for repurposing existing drug ilepcimide for MS therapy.

Identification of ferroptosis-related gene signatures associated with multiple sclerosis using weighted gene co-expression network analysis

Multiple sclerosis (MS) is a chronic inflammatory disease of central nervous system leading to demyelination followed by neurological symptoms. Ferroptosis is a newly discovered pathogenic hallmark important for the progression of MS. However, the gene markers of ferroptosis in MS are still uncertain. In this study, mRNA expression profiles and clinical data of MS samples were retrieved from Gene Expression Omnibus database. Weighted gene co-expression network analysis and receiver operating characteristic curve analysis were utilized to identify ferroptosis-related gene (FRG) signatures of MS. Gene set enrichment analysis and gene set variation analysis were performed to explore the biological functions of single FRG signature. HMOX1, LPCAT3 and RPL8 were firstly identified as FRG signatures of MS with the predictive capacity confirmed. Gene set enrichment analysis and gene set variation analyses revealed that metabolism-related, immune and inflammation-related, microglia-related, oxidation-related, and mitochondria-related biological functions were enriched, providing implications of the mechanisms underlying ferroptosis in MS. This study presented a systematic analysis of FRG in MS and explored the potential ferroptosis targets for new interventional strategies in MS.

Microglia in multiple sclerosis: Protectors turn destroyers

Microglia are implicated in all stages of multiple sclerosis (MS). Microglia alterations are detected by positron emission tomography in people living with MS prior to the formation of structural lesions determined through magnetic resonance imaging. In histological specimens, clusters of microglia form in normal-appearing tissue likely predating the development of lesions. Features of degeneration-associated/pro-inflammatory states of microglia increase with chronicity of MS. However, microglia play many beneficial roles including the removal of neurotoxins and in fostering repair. The protector-gone-rogue microglia in MS is featured herein. We consider mechanisms of microglia neurotoxicity and discuss factors, including aging, osteopontin, and iron metabolism, that cause microglia to lose their protective states and become injurious. We evaluate medications to affect microglia in MS, such as the emerging class of Bruton's tyrosine kinase inhibitors. The framework of microglia-turned-destroyers may instigate new approaches to counter microglia-driven neurodegeneration in MS.

Harpagophytum procumbens Inhibits Iron Overload-Induced Oxidative Stress through Activation of Nrf2 Signaling in a Rat Model of Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) is a common degenerative spinal condition in older individuals that causes impaired walking and other disabilities due to severe lower back and leg pain. Ligamentum flavum hypertrophy is a major LSS cause that may result from oxidative stress caused by degenerative cascades, including imbalanced iron homeostasis that leads to excessive reactive oxygen species production. We investigated the effects of Harpagophytum procumbens (HP) on iron-induced oxidative stress associated with LSS pathophysiology. Primary spinal cord neuron cultures were incubated in FeSO₄-containing medium, followed by addition of 50, 100, or 200 μg/mL HP. Cell viability was assessed by CCK-8 and live/dead cell assays and by propidium iodide-live imaging. In an in vivo rat model of LSS, HP were administered at 100, 200, and 400 mg/kg, and disease progression was monitored for up to 3 weeks. We investigated the in vitro and in vivo effects of HP on iron-induced neurotoxicity by immunochemistry, real-time PCR, and flow cytometry. HP exerted neuroprotective effects and enhanced neurite outgrowths of iron-injured rat primary spinal cord neurons in vitro. HP treatment significantly reduced necrotic cell death and improved cells' antioxidative capacity via the NRF2 signaling pathway in iron-treated neurons. At 1 week after HP administration in LSS rats, the inflammatory response and oxidative stress markers were substantially reduced through regulation of excess iron accumulation. Iron that accumulated in the spinal cord underneath the implanted silicone was also regulated by HP administration via NRF2 signaling pathway activation. HP-treated LSS rats showed gradually reduced mechanical allodynia and amelioration of impaired behavior for 3 weeks. We demonstrated that HP administration can maintain iron homeostasis within neurons via activation of NRF2 signaling and can consequently facilitate functional recovery by regulating iron-induced oxidative stress. This fundamentally new strategy holds promise for LSS treatment.

Effect of Epigallocatechin-3-gallate on Stress-Induced Depression in a Mouse Model: Role of Interleukin-1β and Brain-Derived Neurotrophic Factor

Epigallocatechin 3-gallate (EGCG) is a natural polyphenolic antioxidant in green tea leaves with well-known health-promoting properties. However, the influence of EGCG on a chronic animal model of depression remains to be fully investigated, and the details of the molecular and cellular changes are still unclear. Therefore, the present study aimed to investigate the antidepressant effect of EGCG in mice subjected to chronic unpredictable mild stress (CUMS). After eight consecutive weeks of CUMS, the mice were treated with EGCG (200 mg/kg b.w.) by oral gavage for two weeks. A forced swimming test (FST) was used to assess depressive symptoms. EGCG administration significantly alleviated CUMS-induced depression-like behavior in mice. EGCG also effectively decreased serum interleukin-1β (IL-1β) and increased the mRNA expression levels of brain-derived neurotrophic factor (BDNF) in the hippocampal CA3 region of CUMS mice. Furthermore, electron microscopic examination of CA3 neurons in CUMS mice showed morphological features of apoptosis, loss or disruption of the myelin sheath, and degenerating synapses. These neuronal injuries were diminished with the administration of EGCG. The treatment effect of EGCG in CUMS-induced behavioral alterations was comparable with that of clomipramine hydrochloride (Anafranil), a tricyclic antidepressant drug. In conclusion, our study demonstrates that the antidepressive action of EGCG involves downregulation of serum IL-1β, upregulation of BDNF mRNA in the hippocampus, and reduction of CA3 neuronal lesions.

Positive effect of immunomodulatory therapies on disease progression in Huntington's disease? Data from a real-world cohort

Background:

The role of neuroinflammation and autoimmune processes in neurodegenerative diseases is not fully understood. Activation of microglia with expression of proinflammatory cytokines supports the hypothesis that immune processes may play an important role in the pathophysiology of Huntington’s disease (HD) and thus, immunomodulating therapies might have potential neuroprotective properties. Until now, no disease-modifying therapy (DMT) is available for HD.

Objective:

The aim of this research was to characterize a cohort of patients suffering from both HD and autoimmune demyelinating diseases of the central nervous system (classified as G35-37 in ICD-10; ADD-CNS) in comparison to HD cases without ADD-CNS. In particular, we were interested to investigate potential modulating effects on disease manifestation and progression of HD over time of prescribed immunomodulating medications (DMT).

Methods:

We analyzed the course of HD regarding motoric, functional, and cognitive aspects, using longitudinal data of up to 2 years from the worldwide registry study ENROLL-HD. Additional cross-sectional data in the largest cohort worldwide of HD patients was analyzed using demographic and molecular genetic parameters. Data were analyzed using analysis of variance (ANOVA) for cross-sectional and repeated-measures ANOVA for longitudinal parameters in IBM SPSS Statistics V.27.

Results:

Within the ENROLL-HD database, we investigated N = 21,116 participants and identified n = 60 participants suffering from ADD-CNS. Molecular, genetic, and demographic data did not differ between groups. The subgroup of n = 32 participants with motor-manifest HD revealed better cognitive performance in five out of eight cognitive tests at baseline with less progression over time in two tests (all p < 0.05). Differentiation between DMT-treated and untreated patients revealed better cognitive and motor performance in the DMT group; those patients, however, tended to be younger. Pre-manifest HD patients simultaneously diagnosed with ADD-CNS (n = 12) showed lower functional scores and more decline over time when compared with other pre-manifest HD (p < 0.05).

Conclusion:

Patients suffering from motor-manifest HD and simultaneously from ADD-CNS have better cognitive capacities compared with other motor-manifest HD patients. Moreover, DMTs might have beneficial effects on progression of neurodegeneration including the motor phenotype. However, this effect might have been biased by younger age in DMT-treated patients. Pre-manifest HD patients showed more functional impairment as expected due to their additional ADD-CNS disease.

Emerging therapies to target CNS pathophysiology in multiple sclerosis

The rapidly evolving therapeutic landscape of multiple sclerosis (MS) has contributed to paradigm shifts in our understanding of the biological mechanisms that contribute to CNS injury and in treatment philosophies. Opportunities remain to further improve treatment of relapsing-remitting MS, but two major therapeutic gaps are the limiting of progressive disease mechanisms and the repair of CNS injury. In this Review, we provide an overview of selected emerging therapies that predominantly target processes within the CNS that are thought to be involved in limiting non-relapsing, progressive disease injury or promoting tissue repair. Among these, we consider agents that modulate adaptive and innate CNS-compartmentalized inflammation, which can be mediated by infiltrating immune cells and/or resident CNS cells, including microglia and astrocytes. We also discuss agents that target degenerative disease mechanisms, agents that might confer neuroprotection, and agents that create a more favourable environment for or actively contribute to oligodendrocyte precursor cell differentiation, remyelination and axonal regeneration. We focus on agents that are novel for MS, that are known to or are presumed to penetrate the CNS, and that have already entered early stages of development in MS clinical trials.

Versican promotes T helper 17 cytotoxic inflammation and impedes oligodendrocyte precursor cell remyelination

Remyelination failure in multiple sclerosis (MS) contributes to progression of disability. The deficient repair results from neuroinflammation and deposition of inhibitors including chondroitin sulfate proteoglycans (CSPGs). Which CSPG member is repair-inhibitory or alters local inflammation to exacerbate injury is unknown. Here, we correlate high versican-V1 expression in MS lesions with deficient premyelinating oligodendrocytes, and highlight its selective upregulation amongst CSPG members in experimental autoimmune encephalomyelitis (EAE) lesions modeling MS. In culture, purified versican-V1 inhibits oligodendrocyte precursor cells (OPCs) and promotes T helper 17 (Th17) polarization. Versican-V1-exposed Th17 cells are particularly toxic to OPCs. In NG2^CreER:MAPT^mGFP mice illuminating newly formed GFP⁺ oligodendrocytes/myelin, difluorosamine (peracetylated,4,4-difluoro-N-acetylglucosamine) treatment from peak EAE reduces lesional versican-V1 and Th17 frequency, while enhancing GFP⁺ profiles. We suggest that lesion-elevated versican-V1 directly impedes OPCs while it indirectly inhibits remyelination through elevating local Th17 cytotoxic neuroinflammation. We propose CSPG-lowering drugs as potential dual pronged repair and immunomodulatory therapeutics for MS.

Ghorbani and colleagues describe versican-V1 as an inhibitor of remyelination using transgenic mice that illuminate new GFP ⁺ oligodendrocytes. Mechanisms of versican-V1 include the direct inhibition of oligodendrocytes, and elevating Th17 cells.

Evaluation of Blood-Brain-Barrier Permeability, Neurotoxicity, and Potential Cognitive Impairment by Pseudomonas aeruginosa’s Virulence Factor Pyocyanin

Pyocyanin (PCN) is a redox-active secondary metabolite produced by Pseudomonas aeruginosa as its primary virulence factor. Several studies have reported the cytotoxic potential of PCN and its role during infection establishment and progression. Considering its ability to diffuse through biological membranes, it is hypothesized that PCN can gain entry into the brain and induce oxidative stress across the blood-brain barrier (BBB), ultimately contributing towards reactive oxygen species (ROS) mediated neurodegeneration. Potential roles of PCN in the central nervous system (CNS) have never been evaluated, hence the study aimed to evaluate PCN's probable penetration into CNS through blood-brain barrier (BBB) using both in silico and in vivo (Balb/c mice) approaches and the impact of ROS generation via commonly used tests: Morris water maze test, novel object recognition, elevated plus maze test, and tail suspension test. Furthermore, evidence for ROS generation in the brain was assessed using glutathione S-transferase assay. PCN demonstrated BBB permeability albeit in minute quantities. A significant hike was observed in ROS generation (P < 0.0001) along with changes in behavior indicating PCN permeability across BBB and potentially affecting cognitive functions. This is the first study exploring the potential role of PCN in influencing the cognitive functions of test animals.

A Distinct Hibiscus sabdariffa Extract Prevents Iron Neurotoxicity, a Driver of Multiple Sclerosis Pathology

Iron deposition in the brain begins early in multiple sclerosis (MS) and continues unabated. Ferrous iron is toxic to neurons, yet the therapies used in MS do not counter iron neurotoxicity. Extracts of Hibiscus sabdariffa (HS) are used in many cultures for medicinal purposes. We collected a distinct HS extract and found that it abolished the killing of neurons by iron in culture; medications used in MS were ineffective when similarly tested. Neuroprotection by HS was not due to iron chelation or anthocyanin content. In free radical scavenging assays, HS was equipotent to alpha lipoic acid, an anti-oxidant being tested in MS. However, alpha lipoic acid was only modestly protective against iron-mediated killing. Moreover, a subfraction of HS without radical scavenging activity negated iron toxicity, whereas a commercial hibiscus preparation with anti-oxidant activity could not. The idea that HS might have altered properties within neurons to confer neuroprotection is supported by its amelioration of toxicity caused by other toxins: beta-amyloid, rotenone and staurosporine. Finally, in a mouse model of MS, HS reduced disability scores and ameliorated the loss of axons in the spinal cord. HS holds therapeutic potential to counter iron neurotoxicity, an unmet need that drives the progression of disability in MS.

Quantitative analysis of spinal cord neuropathology in experimental autoimmune encephalomyelitis

Multiple sclerosis is an inflammatory and neurodegenerative condition that is frequently modeled using experimental autoimmune encephalomyelitis (EAE). Current methods of EAE histology include imprecise qualitative assessments and time-consuming analyses of selected regions. With increasing interest in neuroprotective or reparative therapies, it is important that potential therapeutics are evaluated in EAE through quantitative neuropathology. We describe a quantitative whole slide imaging immunofluorescence method that allows longitudinal sections of the entire EAE thoracic spinal cord to be investigated for the extent of neuroinflammation, axonal loss, and myelin density. This method should impact MS research by making histological comparisons of EAE increasingly robust.

Studying the microglia response to oxidized phosphatidylcholine in primary mouse neuron culture and mouse spinal cord

Oxidized phosphatidylcholine (OxPC) found in multiple sclerosis brain lesions mediates neurodegeneration. Microglia are prominent responders to the OxPC insult, and thus, studying their protective or noxious functions is important to help halt neurodegeneration. Here, we present protocols including cell isolation and culture, animal surgeries, as well as tissue processing and isolation to study the microglia response to OxPC-mediated neurodegeneration in vitro and in vivo. For complete details on the use and execution of this protocol, please refer to Dong et al. (2021).

Does Low Grade Systemic Inflammation Have a Role in Chronic Pain?

One of the major clinical manifestations of peripheral neuropathy, either resulting from trauma or diseases, is chronic pain. While it significantly impacts patients’ quality of life, the underlying mechanisms remain elusive, and treatment is not satisfactory. Systemic chronic inflammation (SCI) that we are referring to in this perspective is a state of low-grade, persistent, non-infective inflammation, being found in many physiological and pathological conditions. Distinct from acute inflammation, which is a protective process fighting against intruders, SCI might have harmful effects. It has been associated with many chronic non-communicable diseases. We hypothesize that SCI could be a predisposing and/or precipitating factor in the development of chronic pain, as well as associated comorbidities. We reviewed evidence from human clinical studies indicating the coexistence of SCI with various types of chronic pain. We also collated existing data about the sources of SCI and who could have it, showing that those individuals or patients having SCI usually have higher prevalence of chronic pain and psychological comorbidities. We thus elaborate on the need for further research in the connection between SCI and chronic pain. Several hypotheses have been proposed to explain these complex interactions.

Mechanism-based criteria to improve therapeutic outcomes in progressive multiple sclerosis

In contrast to the multiple disease-modifying therapies that are available for relapsing-remitting multiple sclerosis (MS), the therapeutic options for progressive MS (PMS) are limited. Recent advances in our understanding of the neuroimmunology of PMS, including the mechanisms that drive slowly expanding lesions, have fuelled optimism for improved treatment of this condition. In this Review, we highlight the commonly observed neuropathology of PMS and discuss the associated mechanisms of CNS injury. We then apply this knowledge to formulate criteria for therapeutic efficacy in PMS, beginning with the need for early treatment owing to the substantial neuropathology that is already present at the initial clinical presentation. Other requirements include: antagonism of neuroaxonal injury mediators such as pro-inflammatory microglia and lymphocytes; remediation of oxidative stress resulting from iron deposition and mitochondrial dysfunction; and promotion of neuroprotection through remyelination. We consider whether current disease-modifying therapies for relapsing-remitting MS meet the criteria for successful therapeutics in PMS and suggest that the evidence favours the early introduction of sphingosine 1-phosphate receptor modulators. Finally, we weigh up emerging medications, including repurposed generic medications and Bruton's tyrosine kinase inhibitors, against these fundamental criteria. In this new therapeutic era in PMS, success depends collectively on understanding disease mechanisms, drug characteristics (including brain penetration) and rational use.

Pharmacological insights into autophagy modulation in autoimmune diseases

As a cellular bulk degradation and survival mechanism, autophagy is implicated in diverse biological processes. Genome-wide association studies have revealed the link between autophagy gene polymorphisms and susceptibility of autoimmune diseases including systemic lupus erythematosus (SLE) and inflammatory bowel disease (IBD), indicating that autophagy dysregulation may be involved in the development of autoimmune diseases. A series of autophagy modulators have displayed protective effects on autoimmune disease models, highlighting the emerging role of autophagy modulators in treating autoimmune diseases. This review explores the roles of autophagy in the autoimmune diseases, with emphasis on four major autoimmune diseases [SLE, rheumatoid arthritis (RA), IBD, and experimental autoimmune encephalomyelitis (EAE)]. More importantly, the therapeutic potentials of small molecular autophagy modulators (including autophagy inducers and inhibitors) on autoimmune diseases are comprehensively analyzed.

Hydroxychloroquine for Primary Progressive Multiple Sclerosis

OBJECTIVE

Primary progressive multiple sclerosis (PPMS) does not respond well to immunomodulatory or immunosuppressive treatment. Chronic activation of microglia has been implicated in the pathophysiology of PPMS. The antimalarial drug hydroxychloroquine (HCQ) reduces the activity of human microglia and has neuroprotective effects in vitro.

METHODS

We conducted a single-arm, phase II futility trial of 200 mg oral HCQ twice daily for 18 months. In an effort to investigate disability worsening in the absence of overt focal inflammation, we excluded participants with contrast enhancing lesions on a screening magnetic resonance imaging (MRI). The primary end point was ≥20% worsening on the timed 25-foot walk measured between 6 and 18 months of follow-up.

RESULTS

Based on original trial data, 40% of the cohort were expected to worsen. We used a Simon 2-stage design to compare a null hypothesis of 40% of the cohort worsening against the one-sided alternative of 20%. Using a 5% type 1 error rate and 80% power, HCQ treatment would be deemed successful if fewer than 10 of 35 participants experienced clinically significant worsening. The study met its primary end point, as only 8 of 35 participants worsened between 6 and 18 months. HCQ was overall well-tolerated, with adverse events in 82% and serious adverse events in 12% of participants. All serious adverse events were unlikely related to HCQ use.

INTERPRETATION

HCQ treatment was associated with reduced disability worsening in people with PPMS. HCQ is a promising treatment candidate in PPMS and should be investigated further in randomized controlled clinical trials. ANN NEUROL 2021;90:940-948.

The Effects of PDE Inhibitors on Multiple Sclerosis: a Review of in vitro and in vivo Models

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory and immune-mediated disease, whose current therapeutic means are mostly effective in the relapsing-remitting form of MS, where inflammation is still prominent, but fall short of preventing long term impairment. However, apart from inflammationmediated demyelination, autoimmune mechanisms play a major role in MS pathophysiology, constituting a promising pharmacological target. Phosphodiesterase (PDE) inhibitors have been approved for clinical use in psoriasis and have undergone trials suggesting their neuroprotective effects, rendering them eligible as an option for accessory MS therapy.

OBJECTIVE

In this review, we discuss the potential role of PDE inhibitors as a complementary MS therapy.

METHODS

We conducted a literature search through which we screened and comparatively assessed papers on the effects of PDE inhibitor use, both in vitro and in animal models of MS, taking into account a number of inclusion and exclusion criteria.

RESULTS

In vitro studies indicated that PDE inhibitors promote remyelination and axonal sustenance, while curbing inflammatory cell infiltration, hindering oligodendrocyte and neuronal loss and suppressing cytokine production. In vivo studies underlined that these agents alleviate symptoms and reduce disease scores in MS animal models.

CONCLUSION

PDE inhibitors proved to be effective in addressing various aspects of MS pathogenesis both in vitro and in vivo models. Given the latest clinical trials proving that the PDE4 inhibitor Ibudilast exerts neuroprotective effects in patients with progressive MS, research on this field should be intensified and selective PDE4 inhibitors with enhanced safety features should be seriously considered as prospective complementary MS therapy.

Antidepressants on Multiple Sclerosis: A Review of In Vitro and In Vivo Models

Background

Increased prevalence of depression has been observed among patients with multiple sclerosis (MS) and correlated with the elevated levels of proinflammatory cytokines and the overall deregulation of monoaminergic neurotransmitters that these patients exhibit. Antidepressants have proved effective not only in treating depression comorbid to MS, but also in alleviating numerous MS symptoms and even minimizing stress-related relapses. Therefore, these agents could prospectively prove beneficial as a complementary MS therapy.

Objective

This review aims at illustrating the underlying mechanisms involved in the beneficial clinical effects of antidepressants observed in MS patients.

Methods

Through a literature search we screened and comparatively assessed papers on the effects of antidepressant use both in vitro and in vivo MS models, taking into account a number of inclusion and exclusion criteria.

Results

In vitro studies indicated that antidepressants promote neural and glial cell viability and differentiation, reduce proinflammatory cytokines and exert neuroprotective activity by eliminating axonal loss. In vivo studies confirmed that antidepressants delayed disease onset and alleviated symptoms in Experimental Autoimmune Encephalomyelitis (EAE), the most prevalent animal model of MS. Further, antidepressant agents suppressed inflammation and restrained demyelination by decreasing immune cell infiltration of the CNS.

Conclusion

Antidepressants were efficient in tackling numerous aspects of disease pathophysiology both in vitro and in vivo models. Given that several antidepressants have already proved effective in clinical trials on MS patients, the inclusion of such agents in the therapeutic arsenal of MS should be seriously considered, following an individualized approach to minimize the adverse events of antidepressants in MS patients.

Clozapine Regulates Microglia and Is Effective in Chronic Experimental Autoimmune Encephalomyelitis

Objective

Progressive multiple sclerosis is characterized by chronic inflammation with microglial activation, oxidative stress, accumulation of iron and continuous neurodegeneration with inadequate effectiveness of medications used so far. We now investigated effects of iron on microglia and used the previously identified neuroprotective antipsychotic clozapine in vitro and in chronic experimental autoimmune encephalomyelitis (EAE).

Methods

Microglia were treated with iron and clozapine followed by analysis of cell death and response to oxidative stress, cytokine release and neuronal phagocytosis. Clozapine was investigated in chronic EAE regarding optimal dosing and therapeutic effectiveness in different treatment paradigms. Animals were scored clinically by blinded raters. Spinal cords were analyzed histologically for inflammation, demyelination, microglial activation and iron accumulation and for transcription changes of regulators of iron metabolism and inflammation. Effects on immune cells were analyzed using flow cytometry.

Results

Iron impaired microglial function in vitro regarding phagocytosis and markers of inflammation; this was regulated by clozapine, reflected in reduced release of IL-6 and normalization of neuronal phagocytosis. In chronic EAE, clozapine dose-dependently attenuated clinical signs and still had an effect if applied in a therapeutic setting. Early mild sedative effects habituated over time. Histologically, demyelination was reduced by clozapine and positive effects on inflammation strongly correlated with reduced iron deposition. This was accompanied by reduced expression of DMT-1, an iron transport protein.

Conclusions

Clozapine regulates microglial function and attenuates chronic EAE, even in a therapeutic treatment paradigm. This well-defined generic medication might therefore be considered as promising add-on therapeutic for further development in progressive MS.

Longitudinal Evaluation of the Effect of Tricyclic Antidepressants and Neuroleptics on the Course of Huntington's Disease-Data from a Real World Cohort

Background: Reducing the progress of neurodegeneration is a key goal in Huntington´s disease (HD). A previously performed systematic screening for medications with neuroprotective features identified tricyclic antidepressants and neuroleptics as neuroprotective and mitochondrioprotective agents. Here, we analyzed the characteristics of disease manifestation, progression and potential beneficial effects in HD patients treated with afore-mentioned medications compared to un- and otherwise treated motor-manifest patients in a large real-world cohort over two years. Methods: We analyzed cross-sectional data of the largest cohort worldwide of motor-manifest HD patients using the ENROLL-HD database, including demographic, moleculargenetic, clinical-motoric, cognitive and functional data. Longitudinal data of up to two years were obtained to analyze potential effects on disease progression between groups with different medications used. Data were analyzed using repeated ANOVA-analyses while controlling for the co-variates age and CAG-repeat length. Results: We identified n = 7397 motor-manifest HD patients using no or different medication (HD-ctrl) and subgroups treated with clomipramine (n = 56), clozapine (n = 66), chlorpromazine (n = 17), doxepine (n = 34) and desi-, imi- or trimipramine (n = 19). Demographic parameters, disease onset and CAP-score did not differ. Total motor scores (TMS) at baseline were higher in patients treated with clozapine (p < 0.001), chlorpromazine and clomipramine (p < 0.05) compared to HD-ctrl with higher sub scores for bradykinesia (all p < 0.01) and dystonia in clozapine treated patients (p < 0.001). Functional and cognitive capacities were worse in medication groups in comparison to HD-ctrl at baseline (p < 0.001). Repeated measures analysis of variance documented no differences regarding motoric, functional and cognitive disease progressions between groups. Conclusions: We identified group differences, potentially caused by side effects or potential selection bias in terms of bradykinetic motoric symptoms, more dystonia and lower functional and cognitive performance in some treatment groups at baseline, which were not entirely explained because of underlying fundamental characteristics. Disease progression regarding clinical, functional and cognitive outcomes over two years was not affected by any of the treatment groups compared to HD-ctrl. Our data do not support our hypothesis of a potential neuroprotective effect of these drugs on disease progression.

Repurposing Domperidone in Secondary Progressive Multiple Sclerosis: A Simon 2-Stage Phase 2 Futility Trial

OBJECTIVE

To assess whether treatment with the generic drug domperidone can reduce the progression of disability in secondary progressive multiple sclerosis (SPMS), we conducted a phase 2 futility trial following the Simon 2-stage design.

METHODS

We enrolled patients in an open-label, Simon 2-stage, single-center, phase 2, single-arm futility trial at the Calgary Multiple Sclerosis Clinic if they met the following criteria: age of 18 to 60 years, SPMS, screening Expanded Disability Status Scale score of 4.0 to 6.5, and screening timed 25-ft walk (T25FW) of ≥9 seconds. Patients received domperidone 10 mg 4 times daily for 1 year. The primary outcome was worsening of disability, defined as worsening of the T25FW performance by ≥20% at 12 months compared to baseline. This trial is registered with ClinicalTrials.gov (NCT02308137).

RESULTS

Between February 13, 2015, and January 3, 2020, 110 patients were screened, 81 received treatment, and 64 completed follow-up, of whom 62 were analyzed. The study did not meet its primary endpoint: 22 of 62 (35%) patients experienced significant worsening of disability, which is close to the expected proportion of 40% and above the predefined futility threshold. Patients with higher prolactin levels during the study had a significantly lower risk of disability progression, which may warrant further investigation. Domperidone treatment was reasonably well tolerated, but adverse events occurred in 84% and serious adverse events in 15% of patients.

CONCLUSIONS

Domperidone treatment could not reject futility in reducing disability progression in SPMS. The Simon 2-stage trial model may be a useful model for phase 2 studies in progressive MS.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02308137.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that in individuals with SPMS participating in a futility trial, domperidone treatment could not reject futility in reducing disability progression at 12 months.

The Anti-inflammatory Effect of the Tricyclic Antidepressant Clomipramine and Its High Penetration in the Brain Might Be Useful to Prevent the Psychiatric Consequences of SARS-CoV-2 Infection

At the time of writing (December 2020), coronavirus disease 2019 (COVID-19) has already caused more than one million deaths worldwide, and therefore, it is imperative to find effective treatments. The “cytokine storm” induced by Severe Acute Respiratory Syndrome-Coronavirus type 2 (SARS-CoV-2) is a good target to prevent disease worsening, as indicated by the results obtained with tocilizumab and dexamethasone. SARS-CoV-2 can also invade the brain and cause neuro-inflammation with dramatic neurological manifestations, such as viral encephalitis. This could lead to potentially incapacitating long-term consequences, such as the development of psychiatric disorders, as previously observed with SARS-CoV. Several pathways/mechanisms could explain the link between viral infection and development of psychiatric diseases, especially neuro-inflammation induced by SARS-CoV-2. Therefore, it is important to find molecules with anti-inflammatory properties that penetrate easily into the brain. For instance, some antidepressants have anti-inflammatory action and pass easily through the blood brain barrier. Among them, clomipramine has shown very strong anti-inflammatory properties in vitro, in vivo (animal models) and human studies, especially in the brain. The aim of this review is to discuss the potential application of clomipramine to prevent post-infectious mental complications. Repositioning and testing antidepressants for COVID-19 management could help to reduce peripheral and especially central inflammation and to prevent the acute and particularly the long-term consequences of SARS-CoV-2 infection.

How Does COVID-19 Affect the Neurobiology of Suicide?

PURPOSE OF REVIEW

The aim of this review was to analyze COVID-19 effect on the biological features of suicidal vulnerability and its interaction with suicide-related biological pathways. We carried out a narrative review of international publications on the interactions of COVID-19 with the biological bases of suicide.

RECENT FINDINGS

We hypothesize that SARS-CoV-2 interacts with multiple biological processes that underlie suicidal behavior, such as the renin-angiotensin system, nicotinic receptors, and central and systemic inflammation. Social distancing measures may also worsen subjective or objective social disconnection, thus increasing the risk of suicide. Interestingly, the drugs used to prevent suicide could be promising options to counteract brain damage caused by this coronavirus. SARS-CoV-2 interacts with multiple biological pathways involved in suicide and opens a new window for understanding the suicidal process. The development of suicide prevention treatments in the context of a pandemic may benefit from knowledge on these interactions.

Combination of Hydroxychloroquine and Indapamide Attenuates Neurodegeneration in Models Relevant to Multiple Sclerosis

As the underlying pathophysiology of progressive forms of multiple sclerosis (MS) remains unclear, current treatment strategies are inadequate. Progressive MS is associated with increased oxidative stress and neuronal damage in lesions along with an extensive representation of activated microglia/macrophages. To target these disease mechanisms, we tested the novel combination of generic medications, hydroxychloroquine (HCQ), and indapamide, in tissue culture and in mice. HCQ is an anti-malarial medication found to inhibit microglial activation and to ameliorate disease activity in experimental autoimmune encephalomyelitis. We are currently completing a phase II trial of HCQ in primary progressive MS ( ClinicalTrials.gov Identifier: NCT02913157). Indapamide is an antihypertensive previously discovered in our laboratory drug screen to be an anti-oxidant. As these medications have a different spectrum of activities on disease mechanisms relevant to progressive MS, their use in combination may be more effective than either alone. We thus sought preclinical data for the effectiveness of this combination. In vitro, indapamide had robust hydroxyl scavenging activity, while HCQ and indapamide alone and in combination protected against iron-induced neuronal killing; TNF-α levels in activated microglia were reduced by either drug alone, without additional combination effects. In mice with a lysolecithin lesion that manifests demyelination and axonal loss in the spinal cord, the combination but not individual treatment of HCQ and indapamide reduced CD68+ microglia/macrophage representation in lesions, attenuated axonal injury, and lowered levels of lipid peroxidation. Our study supports the combination of indapamide and HCQ as a new treatment strategy targeting multiple facets of progressive MS.

Molecular signature of slowly expanding lesions in progressive multiple sclerosis

Multiple sclerosis is an immune-mediated chronic inflammatory disease of the CNS that leads to demyelinated lesions in the grey and white matter. Inflammatory, active demyelinating white matter lesions predominate in the relapsing-remitting disease stages, whereas in the progressive stage the so-called slowly expanding lesion is characteristic. These lesions show an accumulation of macrophages/microglia at their borders, mediating the ongoing myelin breakdown and axonal degeneration. The exact pathogenetic mechanisms of lesion progression in chronic multiple sclerosis are still not clear. In the present study, we performed a detailed immunological and molecular profiling of slowly expanding lesions (n = 21) from 13 patients aged between 30 to 74 years (five females and eight males), focusing on macrophage/microglia differentiation. By applying the microglia-specific marker TMEM119, we demonstrate that cells accumulating at the lesion edge almost exclusively belonged to the microglia lineage. Macrophages/microglia can be subdivided into the M1 type, which are associated with inflammatory and degenerative processes, and M2 type, with protective properties, whereby also intermediate polarization phenotypes can be observed. By using a panel of markers characterizing M1- or M2-type macrophages/microglia, we observed a preferential accumulation of M1-type differentiated cells at the lesion edge, indicating a crucial role of these cells in lesion progression. Additionally, unbiased RNA microarray analyses of macrodissected lesion edges from slowly expanding and chronic inactive lesions as well as normal-appearing white matter were performed. In slowly expanding lesions, we identified a total of 165 genes that were upregulated and 35 genes that were downregulated. The upregulated genes included macrophage/microglia-associated genes involved in immune defence and inflammatory processes. Among the upregulated genes were ALOX15B, MME and TNFRSF25. We confirmed increased expression of ALOX15B by quantitative PCR, and of all three genes on the protein level by immunohistochemistry. In conclusion, the present study characterized in detail slowly expanding lesions in progressive multiple sclerosis and demonstrated a preferential accumulation of resident microglia with M1 differentiation at the lesion edge. Microarray analysis showed an increased expression of genes related to immune function, metabolic processes as well as transcription/translation. Thus, these genes may serve as future therapeutic targets to impede lesion progression.

Aging-Exacerbated Acute Axon and Myelin Injury Is Associated with Microglia-Derived Reactive Oxygen Species and Is Alleviated by the Generic Medication Indapamide

Age is a critical risk factor for many neurologic conditions, including progressive multiple sclerosis. Yet the mechanisms underlying the relationship are unknown. Using lysolecithin-induced demyelinating injury to the mouse spinal cord, we characterized the acute lesion and investigated the mechanisms of increased myelin and axon damage with age. We report exacerbated myelin and axon loss in middle-aged (8-10 months of age) compared with young (6 weeks of age) female C57BL/6 mice by 1-3 d of lesion evolution in the white matter. Transcriptomic analysis linked elevated injury to increased expression of Cybb, the gene encoding the catalytic subunit of NADPH oxidase gp91phox. Immunohistochemistry in male and female Cx₃cr1 ^CreER/+ :Rosa26 ^tdTom/+ mice for gp91phox revealed that the upregulation in middle-aged animals occurred primarily in microglia and not infiltrated monocyte-derived macrophages. Activated NADPH oxidase generates reactive oxygen species and elevated oxidative damage was corroborated by higher malondialdehyde immunoreactivity in lesions from middle-aged compared with young mice. From a previously conducted screen for generic drugs with antioxidant properties, we selected the antihypertensive CNS-penetrant medication indapamide for investigation. We report that indapamide reduced superoxide derived from microglia cultures and that treatment of middle-aged mice with indapamide was associated with a decrease in age-exacerbated lipid peroxidation, demyelination and axon loss. In summary, age-exacerbated acute injury following lysolecithin administration is mediated in part by microglia NADPH oxidase activation, and this is alleviated by the CNS-penetrant antioxidant, indapamide.SIGNIFICANCE STATEMENT Age is associated with an increased risk for the development of several neurologic conditions including progressive multiple sclerosis, which is represented by substantial microglia activation. We demonstrate that in the lysolecithin demyelination model in young and middle-aged mice, the latter group developed greater acute axonal and myelin loss attributed to elevated oxidative stress through NADPH oxidase in lineage-traced microglia. We thus used a CNS-penetrant generic medication used in hypertension, indapamide, as we found it to have antioxidant properties in a previous drug screen. Following lysolecithin demyelination in middle-aged mice, indapamide treatment was associated with decreased oxidative stress and axon/myelin loss. We propose indapamide as a potential adjunctive therapy in aging-associated neurodegenerative conditions such as Alzheimer's disease and progressive multiple sclerosis.

Selegiline and clomipramine effects on lymphocyte subsets, regulatory T cells and sheep red blood cell (SRBC)-induced humoral immune response after in vivo administration in mice

We aimed at investigating the influence of clomipramine and selegiline administered in vivo in mice on lymphocyte subsets in lymphoid organs and SRBC-induced humoral immune response. Balb/c mice were given 7 or 14 oral doses (1 mg/kg) of selegiline or clomipramine. Lymphocyte B and T subsets and splenic regulatory T cell (Treg) subset were determined in non-immunized mice 24 and 72 h after the last dose of the drugs. Some mice treated with 7 doses were immunized with sheep red blood cells (SRBC) 2 h after the last dose, and their number of antibody forming cells, haemagglutinin titers and splenocyte subsets were determined. An increase in T lymphocytes and a decrease in B cells were visible in peripheral lymphoid organs, especially after 14 doses of selegiline or clomipramine in non-immunized mice, as well as in spleens of SRBC-immunized mice. The most pronounced change was a decrease in CD4⁺/CD8⁺ ratio resulting mainly from an increase in CD8⁺ subset after seven doses of the drugs in the non-immunized mice. However, it was of a transient nature, as it disappeared after 14 doses of the drugs. The tested drugs only slightly affected thymocyte maturation and did not alter Treg subset. Selegiline and clomipramine transiently stimulated IgG production in SRBC-immunized mice. Both selegiline and clomipramine administered in vivo modulated lymphocyte subsets. This immunomodulatory effect depended on the drug as well as duration of administration.

Neuroprotective Benefits of Antidepressants in Multiple Sclerosis: Are We Missing the Mark?

The potential of antidepressant medication to have a neuroprotective effect for people with multiple sclerosis (MS) has received increased interest in recent years. The possibility of antidepressants, particularly fluoxetine, for potential repurposing to treat primary progressive and secondary progressive MS is of interest as a result of the relative lack of disease-modifying medications for these subtypes. A number of animal studies have found positive results for a neuroprotective effect of antidepressant use in MS, with human studies showing mixed results. These human studies all have a significant limitation: they exclude people with moderate to severe depressive symptoms, a core symptom of MS beyond that of reactive depression. It is likely that reregulation of the common mechanisms in depression and MS, such as inflammation, serotonin, norepinephrine, glutamate and brain-derived neurotropic factor disruption, and hypothalamic-pituitary-thalamic axis dysregulation, are important to the neuroprotective value of antidepressant medication. Given that MS is known for its heterogeneity, the question might be less about whether antidepressant medication provides neuroprotective benefits to people with multiple sclerosis but for whom they provide benefits and whether we are designing studies that will detect a benefit. To answer these questions, studies must include people with MS and depressive symptoms as well as people with relapsing remitting and chronic subtypes.

Clomipramine, a tricyclic antidepressant, and selegiline, a monoamine oxidase-B inhibitor, modulate the activity of phagocytic cells after oral administration in mice

OBJECTIVES

Our aim was to find out whether clomipramine, a tricyclic antidepressant, and selegiline, a monoamine oxidase-B inhibitor, influence the activity of phagocytic cells after in-vivo administration in mice.

METHODS

Clomipramine and selegiline were administered to Balb/c mice orally at a dose of 1 mg/kg, 7 or 14 times. IL-1β and nitric oxide (NO) levels were measured in supernatants of the peritoneal macrophage cultures stimulated in vitro with lipopolysaccharide from Escherichia coli. The phagocytic activity of the granulocytes and monocytes was determined using a commercial Phagotest 24 and 72 h after the last dose of the investigated drugs.

KEY FINDINGS

Seven doses of clomipramine or selegiline decreased IL-1β production, while a rise in its synthesis was observed after 14 doses of selegiline. Clomipramine administered 14 times increased NO production. Clomipramine and selegiline administered seven times reduced the percentage of phagocytosing granulocytes. The drugs administered 14 times increased the percentage of phagocytosing granulocytes and decreased the percentage of phagocytosing monocytes.

CONCLUSIONS

Both clomipramine and selegiline administered in vivo changed the phagocytic activity of blood cells and IL-1β and NO production by murine peritoneal macrophages. This effect depended on the drug, the number of doses and the type of phagocytic cells.

In Vitro and In Vivo Pipeline for Validation of Disease-Modifying Effects of Systems Biology-Derived Network Treatments for Traumatic Brain Injury-Lessons Learned

We developed a pipeline for the discovery of transcriptomics-derived disease-modifying therapies and used it to validate treatments in vitro and in vivo that could be repurposed for TBI treatment. Desmethylclomipramine, ionomycin, sirolimus and trimipramine, identified by in silico LINCS analysis as candidate treatments modulating the TBI-induced transcriptomics networks, were tested in neuron-BV2 microglial co-cultures, using tumour necrosis factor α as a monitoring biomarker for neuroinflammation, nitrite for nitric oxide-mediated neurotoxicity and microtubule associated protein 2-based immunostaining for neuronal survival. Based on (a) therapeutic time window in silico, (b) blood-brain barrier penetration and water solubility, (c) anti-inflammatory and neuroprotective effects in vitro (p < 0.05) and (d) target engagement of Nrf2 target genes (p < 0.05), desmethylclomipramine was validated in a lateral fluid-percussion model of TBI in rats. Despite the favourable in silico and in vitro outcomes, in vivo assessment of clomipramine, which metabolizes to desmethylclomipramine, failed to demonstrate favourable effects on motor and memory tests. In fact, clomipramine treatment worsened the composite neuroscore (p < 0.05). Weight loss (p < 0.05) and prolonged upregulation of plasma cytokines (p < 0.05) may have contributed to the worsened somatomotor outcome. Our pipeline provides a rational stepwise procedure for evaluating favourable and unfavourable effects of systems-biology discovered compounds that modulate post-TBI transcriptomics.

Progressive multiple sclerosis: latest therapeutic developments and future directions

Multiple sclerosis (MS) is a chronic inflammatory condition of the central nervous system leading to demyelination and neurodegeneration. While the initial presentation is mostly characterized by a relapsing-remitting disease, patients often progress naturally after 10-15 years to a secondary-progressive disease course. Another 10-15% present with an initial, primary-progressive MS course. Pathogenic mechanisms possibly driving progression include continued compartmentalized inflammation by T- and B-lymphocytes and cells of innate immunity, oxidative stress, iron accumulation, and consecutive mitochondrial damage, altogether leading to neurodegeneration with accumulation of disability. Increasing knowledge about pathogenic mechanisms involved in progressive MS helps to design more specific and precise therapeutic approaches. Successful examples are the B-cell targeting monoclonal antibody ocrelizumab, effective in primary progressive MS, and the sphingosine-1-receptor modulator siponimod, effective in active forms of secondary-progressive MS. Apart from that, other medications such as the B-cell targeted antibody ofatumumab, cladribine due to T- and B-cell depletion, and other sphingosine-1-receptor modulators such as ozanimod and ponesimod are under development. Moreover, some therapeutic approaches in preclinical stages are under development. In this review, we will summarize the newest therapeutic development in the field of progressive MS of the last 3 years, and shed light on auspicious substances with similar mechanisms and new developments in the therapeutic pipeline, presumably supporting a bright future for progressive MS treatment.

Inhibitory milieu at the multiple sclerosis lesion site and the challenges for remyelination

Regeneration of myelin, following injury, can occur within the central nervous system to reinstate proper axonal conductance and provide trophic support. Failure to do so renders the axons vulnerable, leading to eventual degeneration, and neuronal loss. Thus, it is essential to understand the mechanisms by which remyelination or failure to remyelinate occur, particularly in the context of demyelinating and neurodegenerative disorders. In multiple sclerosis, oligodendrocyte progenitor cells (OPCs) migrate to lesion sites to repair myelin. However, during disease progression, the ability of OPCs to participate in remyelination diminishes coincident with worsening of the symptoms. Remyelination is affected by a broad range of cues from intrinsic programming of OPCs and extrinsic local factors to the immune system and other systemic elements including diet and exercise. Here we review the literature on these diverse inhibitory factors and the challenges they pose to remyelination. Results spanning several disciplines from fundamental preclinical studies to knowledge gained in the clinic will be discussed.

Progressive multiple sclerosis: from pathophysiology to therapeutic strategies

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that involves demyelination and axonal degeneration. Although substantial progress has been made in drug development for relapsing-remitting MS, treatment of the progressive forms of the disease, which are characterized clinically by the accumulation of disability in the absence of relapses, remains unsatisfactory. This unmet clinical need is related to the complexity of the pathophysiological mechanisms involved in MS progression. Chronic inflammation, which occurs behind a closed blood-brain barrier with activation of microglia and continued involvement of T cells and B cells, is a hallmark pathophysiological feature. Inflammation can enhance mitochondrial damage in neurons, which, consequently, develop an energy deficit, further reducing axonal health. The growth-inhibitory and inflammatory environment of lesions also impairs remyelination, a repair process that might protect axons from degeneration. Moreover, neurodegeneration is accelerated by the altered expression of ion channels on denuded axons. In this Review, we discuss the current understanding of these disease mechanisms and highlight emerging therapeutic strategies based on these insights, including those targeting the neuroinflammatory and degenerative aspects as well as remyelination-promoting approaches.

Comorbidities in multiple sclerosis-a plea for interdisciplinary collaboration to improve the quality of life of MS patients

The negative influence of comorbidities on the quality of life of people with multiple sclerosis is evident and the problem is increasingly acknowledged by numerous international studies in long-term care. One therapeutic option would be an add-on therapy with vitamin D (VD), with the aim of achieving a therapeutically effective dose. The individually required VD dose must be tested, since the response to a certain dose is subject to variations between individuals. A possible toxicity with increased 1.25(OH)D3 (active VD metabolite) is largely prevented by increased activity of 24-hydroxylase (CYP24A1). Monitoring of serum VD levels as well as serum calcium and phosphate levels (optional Ca excretion in 24-hour urine, Ca creatinine ratio in urine) provides safety and is necessary because possible mutations on the (catabolic) CYP24A1 gene can lead to a partial or total loss of 24-hydroxylase activity and provoke hypercalcemia/hyperphosphatemia. The main therapeutic objective is to maintain functional and social independence by using drugs with a high safety profile. The prevention and optimal management of comorbidities can influence the quality of life of patients with MS (PwMS) when included in patient care. Adequate measures can reduce the burden of MS only if the risk of comorbidity is reduced through targeted monitoring, early detection and diagnosis. Such a strategy will contribute to influencing the premature mortality of patients with MS. If VD is recognized as a "multipurpose steroid hormone", it could also be used to maintain cognitive function and prevent premature possible dementia, especially as there is evidence that VD deficiency correlates with brain atrophy (hippocampus). At present, MS therapy is still a balancing act between therapeutically efficient action and the management of unexpected side effects, with VD add-on therapy being almost unproblematic and most likely to be accepted by PwMS.

Pharmacotherapy in Secondary Progressive Multiple Sclerosis: An Overview

Multiple sclerosis is an immune-mediated inflammatory disease of the central nervous system characterised by demyelination, neuroaxonal loss and a heterogeneous clinical course. Multiple sclerosis presents with different phenotypes, most commonly a relapsing-remitting course and, less frequently, a progressive accumulation of disability from disease onset (primary progressive multiple sclerosis). The majority of people with relapsing-remitting multiple sclerosis, after a variable time, switch to a stage characterised by gradual neurological worsening known as secondary progressive multiple sclerosis. We have a limited understanding of the mechanisms underlying multiple sclerosis, and it is believed that multiple genetic, environmental and endogenous factors are elements driving inflammation and ultimately neurodegeneration. Axonal loss and grey matter damage have been regarded as amongst the leading causes of irreversible neurological disability in the progressive stages. There are over a dozen disease-modifying therapies currently licenced for relapsing-remitting multiple sclerosis, but none of these has provided evidence of effectiveness in secondary progressive multiple sclerosis. Recently, there has been some early modest success with siponimod in secondary progressive multiple sclerosis and ocrelizumab in primary progressive multiple sclerosis. Finding treatments to delay or prevent the courses of secondary progressive multiple sclerosis is an unmet and essential goal of the research in multiple sclerosis. In this review, we discuss new findings regarding drugs with immunomodulatory, neuroprotective or regenerative properties and possible treatment strategies for secondary progressive multiple sclerosis. We examine the field broadly to include trials where participants have progressive or relapsing phenotypes. We summarise the most relevant results from newer investigations from phase II and III randomised controlled trials over the past decade, with particular attention to the last 5 years.

An industry update: what is the latest news in the therapeutic delivery field?

The present industry update covers the period 1–31 December 2017. Information was sourced primarily from scientific literature and various news websites, company press releases, regulatory and patent agencies. The most representative (not all) examples of research are herein described and they are mainly focused on metabolic diseases, cancer, blood pressure diseases, eyes diseases and, in some cases, in rare diseases. In this paper, there was a clear positive approval tendency for several companies where they offered novel therapeutic delivery candidates. Some patents related to the therapeutic field were also published during this month. Finally, the US FDA announced the availability of a draft guidance for industry for products containing nanomaterials (investigational, pre-market and post-market submissions).