The role of immune cells, glia and neurons in white and gray matter pathology in multiple sclerosis

Revisiting the role of sexual hormones in the demyelinated central nervous system

Sex-related differences characterize multiple sclerosis, an autoimmune, inflammatory and neurodegenerative disease displaying higher incidence in females as well as discrepancies in susceptibility and progression. Besides clinical specificities, molecular and cellular differences related to sex hormones were progressively uncovered improving our understanding of the mechanisms involved in this disabling disease. The most recent findings may give rise to the identification of novel therapeutic perspectives that could meet the urgent need for a treatment preventing the transition from the recurrent- to the progressive form of the disease. The present review is an update of our current knowledge about progestagens, androgens and estrogens in the context of CNS demyelination including their synthesis, the impact of their dysregulation, the preclinical and clinical data presently available, the main molecular dimorphisms related to these hormones and their age-related changes and relationship with failure of spontaneous remyelination, likely impacting the inexorable progression of multiple sclerosis towards irreversible disabilities.

Pyroptosis the Emerging Link Between Gut Microbiota and Multiple Sclerosis

This review elucidates the pivotal role of pyroptosis, triggered by gut microbiota, in the development of multiple sclerosis (MS), emphasizing its significance within the gut-brain axis. Our comprehensive analysis of recent literature reveals how dysbiosis in the gut microbiota of MS patients-characterized by reduced microbial diversity and shifts in bacterial populations-profoundly impacts immune regulation and the integrity of the central nervous system (CNS). Pyroptosis, an inflammatory form of programmed cell death, significantly exacerbates MS by promoting the release of inflammatory cytokines and causing substantial damage to CNS tissues. The gut microbiota facilitates this detrimental process through metabolites such as short-chain fatty acids and neuroactive compounds, or self-structural products like lipopolysaccharides (LPS), which modulate immune responses and influence neuronal survival. This review highlights the potential of modulating gut microbiota to regulate pyroptosis, thereby suggesting that targeting this pathway could be a promising therapeutic strategy to mitigate inflammatory responses and preserve neuronal integrity in patients with MS.

Glial Cells as Key Regulators in Neuroinflammatory Mechanisms Associated with Multiple Sclerosis

Even though several highly effective treatments have been developed for multiple sclerosis (MS), the underlying pathological mechanisms and drivers of the disease have not been fully elucidated. In recent years, there has been a growing interest in studying neuroinflammation in the context of glial cell involvement as there is increasing evidence of their central role in disease progression. Although glial cell communication and proper function underlies brain homeostasis and maintenance, their multiple effects in an MS brain remain complex and controversial. In this review, we aim to provide an overview of the contribution of glial cells, oligodendrocytes, astrocytes, and microglia in the pathology of MS during both the activation and orchestration of inflammatory mechanisms, as well as of their synergistic effects during the repair and restoration of function. Additionally, we discuss how the understanding of glial cell involvement in MS may provide new therapeutic targets either to limit disease progression or to facilitate repair.

Oligoclonal band count as a marker of disease activity and progression in multiple sclerosis: A multicenter study

BACKGROUND

Cerebrospinal fluid (CSF) biomarkers provide critical insights into the pathophysiology and progression of multiple sclerosis (MS), as this study aimed to investigate the relationships between CSF oligoclonal band (OCB) counts and the clinical course and short-term prognosis of MS patients.

METHODS

A retrospective cohort analysis covering a five-year period was conducted at two MS centers. Data on demographics, clinical presentation, MRI findings, EDSS scores, annualized relapse rate (ARR) in the first two years, and CSF analyses were analyzed.

RESULTS

Among 310 patients, the ages ranged from 19 to 73 years, with a mean age of 38 years. OCBs were detected in 86.5 % (n = 268) of the patients. Those with a greater number of OCB bands had significantly more upper cervical lesions and T2 lesions (p < 0.05). A weak positive correlation was found between OCB and the IgG index score. No significant relationship was observed between band count and the ARR or EDSS score. OCB-positive patients had higher IgG index scores and more upper cervical lesions (p < 0.05). Additionally, patients with elevated IgG index levels (>0.7) exhibited significantly greater EDSS scores and more T2 lesions (p < 0.05).

CONCLUSIONS

This study highlights the importance of OCB counts as a significant marker for assessing disease activity and progression in MS patients. These findings emphasize the need for a comprehensive approach that integrates CSF analysis with clinical and radiological data to effectively manage MS and tailor treatment strategies.

Coffee and multiple sclerosis (MS)

Multiple Sclerosis (MS) is a long-term autoimmune disorder affecting the central nervous system, marked by inflammation, demyelination, and neurodegeneration. While the exact cause of MS remains unknown, recent research indicates that environmental factors, particularly diet, may influence the disease's risk and progression. As a result, the potential neuroprotective effects of coffee, one of the most popular beverages worldwide, have garnered significant attention due to its rich content of bioactive compounds. This chapter explores the impact of coffee consumption on patients with Multiple Sclerosis, highlighting how coffee compounds like caffeine, polyphenols, and diterpenes can reduce inflammation and oxidative stress while enhancing neural function. It highlights caffeine's effect in regulating adenosine receptors, specifically A1R and A2AR, which play important roles in neuroinflammation and neuroprotection in MS. The dual role of microglial cells, which promote inflammation while also aiding neuroprotection, is also highlighted concerning caffeine's effects. Furthermore, the potential of A2AR as a therapeutic target in MS and the non-A2AR-dependent neuroprotective benefits of coffee. In this chapter we suggest that the consumption of coffee has no harmful effect on an MS patient and to a larger extent on public health, and informs future research directions and clinical practice, ultimately improving outcomes for individuals living with MS.

Inflammasome Molecular Insights in Autoimmune Diseases

Autoimmune diseases (AIDs) emerge due to an irregular immune response towards self- and non-self-antigens. Inflammation commonly accompanies these conditions, with inflammatory factors and inflammasomes playing pivotal roles in their progression. Key concepts in molecular biology, inflammation, and molecular mimicry are crucial to understanding AID development. Exposure to foreign antigens can cause inflammation, potentially leading to AIDs through molecular mimicry triggered by cross-reactive epitopes. Molecular mimicry emerges as a key mechanism by which infectious or chemical agents trigger autoimmunity. In certain susceptible individuals, autoreactive T or B cells may be activated by a foreign antigen due to resemblances between foreign and self-peptides. Chronic inflammation, typically driven by abnormal immune responses, is strongly associated with AID pathogenesis. Inflammasomes, which are vital cytosolic multiprotein complexes assembled in response to infections and stress, are crucial to activating inflammatory processes in macrophages. Chronic inflammation, characterized by prolonged tissue injury and repair cycles, can significantly damage tissues, thereby increasing the risk of AIDs. Inhibiting inflammasomes, particularly in autoinflammatory disorders, has garnered significant interest, with pharmaceutical advancements targeting cytokines and inflammasomes showing promise in AID management.

The Smoothened agonist SAG Modulates the Male and Female Peripheral Immune Systems Differently in an Immune Model of Central Nervous System Demyelination

Both Hedgehog and androgen signaling pathways are known to promote myelin regeneration in the central nervous system. Remarkably, the combined administration of agonists of each pathway revealed their functional cooperation towards higher regeneration in demyelination models in males. Since multiple sclerosis, the most common demyelinating disease, predominates in women, and androgen effects were reported to diverge according to sex, it seemed essential to assess the existence of such cooperation in females. Here, we developed an intranasal formulation containing the Hedgehog signaling agonist SAG, either alone or in combination with testosterone. We show that SAG promotes myelin regeneration and presumably a pro-regenerative phenotype of microglia, thus mimicking the effects previously observed in males. However, unlike in males, the combined molecules failed to cooperate in the demyelinated females, as shown by the level of functional improvement observed. Consistent with this observation, SAG administered in the absence of testosterone amplified peripheral inflammation by presumably activating NK cells and thus counteracting a testosterone-induced reduction in Th17 cells when the molecules were combined. Altogether, the data uncover a sex-dependent effect of the Hedgehog signaling agonist SAG on the peripheral innate immune system that conditions its ability to cooperate or not with androgens in the context of demyelination.

Ameliorative effects of acetyl-L-carnitine on corpus callosum and functional recovery in demyelinated mouse model

AIM

Multiple sclerosis (MS) is the most common chronic inflammatory demyelinating disease of the central nervous system. Oxidative stress via distinct pathobiological pathways plays a pivotal role in the formation and persistence of MS lesions. Acetyl-L-carnitine (ALC) facilitates the uptake of acetyl coenzyme-A into the mitochondria by a fatty acid oxidation process. ALC could be a therapeutic antioxidant in the myelin repair process. This study explored the potential neuroprotective effects of ALC in cuprizone (CPZ) intoxicated mice.

MATERIALS AND METHODS

Thirty male C57BL/6 mice were divided into three groups. The control animals received a normal diet. The CPZ and CPZ + ALC groups were fed with a 0.2% cuprizone diet for 12 weeks. In the CPZ + ALC group, animals received ALC (300 mg/kg/day) from the 10th -12th weeks. Animals were evaluated functionally by beam walking test (BWT) weekly. Eventually, the corpus callosum (CC) was extracted for histological, biochemical, and molecular studies.

RESULTS

BWT data showed ALC significantly improves balance and gait in the demyelinating mouse model. Histological staining represented ALC effectively increased remyelination in the CC. Biochemical evaluations demonstrated ALC decreased the malondialdehyde level with a parallel increase in the reduced glutathione and catalase activity levels in the CC. Molecular analysis revealed that ALC significantly increased the expression of oligodendrocyte transcription-2 (Olig-2) and Poly lipoproteins (Plp) genes in the CC.

CONCLUSIONS

ALC improved balance and motor coordination in the demyelinated mouse model. It may be by reducing the levels of free radicals and increasing the expression of Olig-2 and Plp as myelin-related genes.

Metformin treatment reduces inflammation, dysmyelination and disease severity in a mouse model of multiple sclerosis, experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation, death or damage of oligodendrocytes, and axonal degeneration. Current MS treatments are non-curative, associated with undesired side-effects, and expensive, highlighting the need for expanded therapeutic options for patients. There is great interest in developing interventions using drugs or therapeutics to reduce symptom onset and protect pre-existing myelin. Metformin is a well-tolerated drug used to treat Type 2 diabetes that has pleiotropic effects in the central nervous system (CNS), including reducing inflammation, enhancing oligodendrogenesis, increasing the survival/proliferation of neural stem cells (NSCs), and increasing myelination. Here, we investigated whether metformin administration could improve functional outcomes, modulate oligodendrocyte precursor cells (OPCs), and reduce inflammation in a well-established mouse model of MS- experimental autoimmune encephalomyelitis (EAE). Male and female mice received metformin treatment at the time of EAE induction ("acute") or upon presentation of disease symptoms ("delayed"). We found that acute metformin treatment improved functional outcomes, concomitant with reduced microglia numbers and decreased dysmyelination. Conversely, delayed metformin treatment did not improve functional outcomes. Our findings reveal that metformin administration can improve EAE outcomes when administered before symptom onset in both sexes.

Age-Dependent Effects of Transgenic 2D2 Mice Used to Induce Passive Experimental Autoimmune Encephalomyelitis in C57BL/6 Mice

INTRODUCTION

Multiple sclerosis (MS) is a neurodegenerative autoimmune disease that worsens with age. Here, we examined the influence of age on passive experimental autoimmune encephalomyelitis (P-EAE), a model to study MS, using young and mature adult 2D2 transgenic donor mice to induce pathology in WT C57BL6/J mice.

METHODS

Lymphocytes from young adult (i.e., 10-week-old) or mature adult (i.e., 6-month-old) transgenic donor mice were characterized by flow cytometry prior to injection of cultured leukocytes into adult female WT recipient mice, with a special focus on transgenic T cell phenotypes.

RESULTS

Our findings show age-dependent changes in memory T cell phenotypes correlated with more severe clinical and histological disease when donor cells originated from young as compared to mature adult mice.

CONCLUSION

Not only do these results demonstrate that the age of the 2D2 transgenic donor mice is critical in establishing P-EAE, but the differential effects might also identify age-dependent factors that contribute to EAE and perhaps MS.

Stress promotes the infiltration of peripheral immune cells to the brain

Immune cells and the brain have a privileged interaction. Here, we report changes in the hippocampal immune microenvironment at the single cell level after stress, uncovering the tight orchestration of immune cell infiltration into the hippocampus after stress to maintain homeostasis. We show the distribution of several immune cell types in the hippocampus associated with their susceptibility or resilience to the learned helplessness paradigm in a sex- and microbiota-dependent manner using single-cell RNA sequencing and bioinformatic tools, flow cytometry, and immunofluorescence. We uncovered the presence of tissue-resident memory T cells that accumulate over time in the hippocampus of learned helpless mice, and the presence of CD74-expressing myeloid cells. These cells were found by a knockdown approach to be critical to induce resilience to learned helplessness. Altogether, these findings provide a novel overview of the neuro-immune repertoire and its impact on the landscape of the hippocampus after learned helplessness.

Emodin attenuates inflammation and demyelination in experimental autoimmune encephalomyelitis

Emodin, a substance extracted from herbs such as rhubarb, has a protective effect on the central nervous system. However, the potential therapeutic effect of emodin in the context of multiple sclerosis remains unknown. In this study, a rat model of experimental autoimmune encephalomyelitis was established by immune induction to simulate multiple sclerosis, and the rats were intraperitoneally injected with emodin (20 mg/kg/d) from the day of immune induction until they were sacrificed. In this model, the nucleotide-binding domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and the microglia exacerbated neuroinflammation, playing an important role in the development of multiple sclerosis. In addition, silent information regulator of transcription 1 (SIRT1)/peroxisome proliferator-activated receptor-alpha coactivator (PGC-1α) was found to inhibit activation of the NLRP3 inflammasome, and SIRT1 activation reduced disease severity in experimental autoimmune encephalomyelitis. Furthermore, treatment with emodin decreased body weight loss and neurobehavioral deficits, alleviated inflammatory cell infiltration and demyelination, reduced the expression of inflammatory cytokines, inhibited microglial aggregation and activation, decreased the levels of NLRP3 signaling pathway molecules, and increased the expression of SIRT1 and PGC-1α. These findings suggest that emodin improves the symptoms of experimental autoimmune encephalomyelitis, possibly through regulating the SIRT1/PGC-1α/NLRP3 signaling pathway and inhibiting microglial inflammation. These findings provide experimental evidence for treatment of multiple sclerosis with emodin, enlarging the scope of clinical application for emodin.

Early prognosticators of later TSPO-PET-measurable microglial activation in multiple sclerosis

BACKGROUND

Factors driving increased innate immune cell activation in multiple sclerosis (MS) brain are not well understood. As higher prevalence of microglial/macrophage activation in association with chronic lesions and diffusely in the normal appearing white matter predict more rapid accumulation of clinical disability, it is of high importance to understand processes behind this. Objective of the study was to explore demographic, clinical and paraclinical variables associating with later positron emission tomography (PET)-measurable innate immune cell activation.

METHODS

PET-imaging using a TSPO-binding [¹¹C]PK11195 was performed to evaluate microglial activation in patients with relapsing-remitting MS aged 40-55 years with a minimum disease duration of five years (n = 37). Medical records and diagnostic MR images were reviewed for relevant early MS disease-related clinical and paraclinical parameters.

RESULTS

More prominent microglial activation was associated with higher number of T2 lesions in the diagnostic MRI, a higher immunoglobulin G (IgG) index in the diagnostic CSF and Expanded Disability Status Scale (EDSS) ≥ 2.0 five years after diagnosis.

CONCLUSION

The number of T2 lesions in MRI, and CSF immunoglobulin content measured by IgG index at the time of MS diagnosis associated with later TSPO-PET-measurable innate immune cell activation. This suggests that both focal and diffuse early inflammatory phenomena impact the development of later progression-related pathology.

Extracellular vesicles as contributors in the pathogenesis of multiple sclerosis

Extracellular vesicles (EVs) are a heterogeneous family of extracellular structures bounded by a phospholipid bilayer, released by all cell types in various biological fluids, such as blood and cerebrospinal fluid (CSF), playing important roles in intercellular communication, both locally and systemically. EVs carry and deliver a variety of bioactive molecules (proteins, nucleic acids, lipids and metabolites), conferring epigenetic and phenotypic changes to the recipient cells and thus resulting as important mediators of both homeostasis and pathogenesis. In neurological diseases, such as multiple sclerosis (MS), the EV ability to cross Blood-Brain Barrier (BBB), moving from central nervous system (CNS) to the peripheral circulation and vice versa, has increased the interest in EV study in the neurological field. In the present review, we will provide an overview of the recent advances made in understanding the pathogenic role of EVs regarding the immune response, the BBB dysfunction and the CNS inflammatory processes.

Ponesimod: An Oral Second-Generation Selective Sphingosine 1-Phosphate Receptor Modulator for the Treatment of Multiple Sclerosis

OBJECTIVE

To describe the safety, efficacy, and potential role in therapy of ponesimod, which was recently approved by the Food and Drug Administration (FDA) as a therapeutic option for the treatment of multiple sclerosis (MS).

DATA SOURCES

A PubMed literature search using the following terms: ponesimod and MS (January 1, 2012-October 31, 2022). FDA product labeling was also reviewed for pertinent data sources.

STUDY SELECTION AND DATA EXTRACTION

All relevant English-language articles examining efficacy and/or safety of ponesimod were considered for inclusion.

DATA SYNTHESIS

Ponesimod is an orally administered second-generation sphingosine 1-phospate (S1-P) receptor modulator classified as a disease modifying treatment (DMT) for MS. Clinical studies have shown that ponesimod prevents relapse in patients with relapsing-remitting MS (RRMS) and has superior efficacy compared with teriflunomide. Nasopharyngitis, upper respiratory tract infections, headache, high blood pressure, and liver dysfunction were some of the common adverse effects associated with ponesimod. Dyspnea, bradyarrhythmias, atrioventricular conduction delays, and macular edema were some of the rare but serious adverse effects associated with ponesimod.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON WITH EXISTING AGENTS

Some advantages of ponesimod over other S1-P receptor modulators approved for RRMS include selectivity for the S1-P₁ receptor and short half-life, which allows for quick reversal of immunosuppressive effects. However, data from long-term efficacy and safety studies and more direct comparison studies with other DMTs are required.

CONCLUSION

Currently available data suggest that ponesimod is a useful addition to other high-efficacy DMTs available to treat patients with MS.

Wuzi Yanzong Pill relieves CPZ-induced demyelination by improving the microenvironment in the brain

Ethnopharmacology relevance

Wuzi Yanzong Pill (WYP), a well-known prescription for invigorating the kidney and essence, which is widely used to treat infertility such as oligoasthenospermia. Studies have shown that WYP can be used to treat neurological diseases, but its therapeutic effects and mechanisms for multiple sclerosis (MS) remain unclear.

Aim of the study

Based on the establishment of Cuprizone (CPZ)-induced demyelination model, this study determined the effect of WYP on remyelination by detecting changes in the microenvironment of the central nervous system.

Materials and methods

C57BL/6 mice were divided into three groups. The CPZ group and CPZ + WYP group were fed with 0.2% CPZ feed, and the control group was fed normal feed, for 6 weeks. At the end of the second week, the CPZ + WYP group was gavaged with WYP solution (16 g/kg/d), and the other two groups were gavaged with normal saline twice a day with an interval of 12 h each time, for 4 weeks. Forced swimming and elevated plus maze were used to detect changes in anxiety and depression before and after treatment. Luxol fast blue staining and the expression of MBP were used to evaluate the demyelination of the brain. Western blot was used to detect the expression of microglia and their subtype markers Iba-1, Arg-1, iNOS, the expression of neurotrophic factors BDNF, GDNF, CNTF, and the expression of oligodendrocyte precursor cells NG2. ELISA detected the content of IL-6, IL-1β, IL-10, TGF-β, BDNF, GDNF, CNTF in the brain. The distribution of Iba-1 in the corpus callosum was observed by immunofluorescence.

Results

The results showed that on the basis of improving mood abnormalities and demyelination, WYP reduced the protein content of Iba-1 and iNOS, increased the protein content of Arg-1, and reduce accumulation of microglia in the corpus callosum. In addition, WYP reduced the secretion of IL-6 and IL-1β while promoting the secretion of IL-10 and TGF-β. After WYP intervention treatment, the levels of neurotrophic factors BDNF, GDNF, CNTF increased. Due to the improvement of inflammatory and nutritional environment in the CNS, promoting the proliferation of NG2 oligodendrocyte, increased the expression of MBP, and repairing myelin sheath.

Conclusion

Our results indicated that WYP promoted the proliferation and development of oligodendrocytes by improving the CNS microenvironment, effectively alleviating demyelination.

Brain proteome-wide association study linking-genes in multiple sclerosis pathogenesis

OBJECTIVES

To identify genes that confer MS risk via the alteration of cis-regulated protein abundance and verify their aberrant expression in human brain.

METHODS

Utilizing a two-stage proteome-wide association study (PWAS) design, MS GWAS data (N = 41,505) was respectively integrated with two distinct human brain proteomes from the dorsolateral prefrontal cortex, including ROSMAP (N = 376) in the discovery stage and Banner (N = 152) in the confirmation stage. In the following, Bayesian colocalization analysis was conducted for GWAS and protein quantitative trait loci signals to prioritize candidate genes. Differential expression analysis was then used to verify the dysregulation of risk genes in white matter and gray matter for evidence at the transcription level.

RESULTS

A total of 51 genes whose protein abundance had association with the MS risk were identified, of which 18 genes overlapped in the discovery and confirmation PWAS. Bayesian colocalization indicated six causal genes with genetic risk variants for the MS risk. The differential expression analysis of SHMT1 (P_FDR  = 4.82 × 10^-2 ), FAM120B (P_FDR  = 8.13 × 10^-4 ) in white matter and ICA1L (P_FDR  = 3.44 × 10^-2 ) in gray matter confirmed the dysregulation at the transcription level. Further investigation of expression found SHMT1 significantly up-regulated in white matter lesion, and FAM120B up-regulated in both white matter lesion and normal appearing white matter. ICA1L was down-regulated in both gray matter lesion and normal appearing gray matter.

INTERPRETATION

Dysregulation of SHMT1, FAM120B and ICA1L may confer MS risk. Our findings shed new light on the pathogenesis of MS and prioritized promising targets for future therapy research.

Evidence for novel cell defense mechanisms sustained by dimethyl fumarate in multiple sclerosis patients: the HuR/SOD2 cascade

BACKGROUND

Dimethyl fumarate (DMF) is an effective treatment for relapsing remitting Multiple Sclerosis (MS) and its mechanisms of action encompass immunomodulatory and cytoprotective effects. Despite DMF is known to activate the Nrf2 pathway, Nrf2-independent mechanisms have been also reported and new insights on the underlying molecular mechanisms are still emerging including transcriptional and post-transcriptional events. At this regard, we focused on a small family of RNA-binding proteins, the ELAV-like proteins, that play a pivotal role in post-transcriptional mechanisms and are involved in the pathogenesis of several psychiatric and neurologic disorders. HuR, the ubiquitously expressed member of the family, is implicated in many cellular functions, including survival, inflammation and proper functioning of the immune system. We previously documented the potential entanglement of HuR in MS pathogenesis. In the present work, we explored HuR protein levels in peripheral blood mononuclear cells (PBMCs) from MS patients before and after DMF treatment compared to healthy controls (HC). Considering that HuR may act on various targets, playing a protective role against oxidative stress, our main goals were to evaluate whether manganese-dependent superoxide dismutase transcript (SOD2) could represent a new molecular target of HuR and to study the potential influence of DMF treatment on this interaction.

METHODS

PBMCs from 20 patients with MS and 20 frequency-matched HC by sex and age were used to evaluate HuR, MnSOD (the protein coded by SOD2) and Nrf2 protein content by Western blot, before and after 12 months of DMF treatment. Immunoprecipitation experiments coupled with RNA extraction in PBMCs were performed to explore whether SOD2 mRNA could be physically bound by HuR and whether the expression of MnSOD protein could be affected by 12 months of DMF treatment.

RESULTS

In PBMCs, HuR protein binds SOD2 transcript in HC and in MS patients naïve to disease modifying treatment. The expression of MnSOD protein is positively affected by 12 months of DMF treatment. PBMCs from MS patients have a lower HuR and MnSOD protein content compared to matched HC (HuR: p<0.01, MnSOD: p<0.01). Of interest, 12 months of DMF treatment in MS patients restores the amount of both HuR protein and MnSOD enzyme to the levels observed in HC. We also confirmed that Nrf2 is an HuR target, and we report that its levels are significantly increased in MS patients naïve to disease modifying treatment and remain elevated following DMF administration.

CONCLUSION

SOD2 transcript is a new target of HuR protein. DMF induces an increased expression of HuR protein, which ultimately interacts more strongly with SOD2 transcript promoting the expression of this antioxidant protein. The activation of this molecular cascade can constitute an additional tool that the cells can exploit to counteract the oxidative stress associated with MS development, and can account for the multifaceted molecular mechanisms underlying DMF efficacy in MS.

Impact of Multiple Sclerosis and Its Association with Depression: An Analytical Case-Control Investigation

Multiple sclerosis (MS) is a neurological, chronic, inflammatory, and progressive disease with musculoskeletal problems and neurodegenerative disorders that causes worsening of the health status of patients. The aim of this study was to determine the level of depression in MS patients compared to a population of healthy subjects. The established sample size was 116 subjects matched with the same age, sex, and body mass index. The subjects were recruited from different multiple sclerosis associations and neurology clinics in different public health areas (case group n = 58) and healthy subjects from the same locality (control group n = 58). The scores and categories of the Beck Depression Inventory (BDI) in its Spanish version were collected. There was a clear statistically significant difference (p < 0.05) in the BDI scores between both groups. As a result, we found that the subjects with MS presented worse results with BDI = 9.52 ± 7.70 points compared to the healthy subjects with a BDI score = 5.03 ± 5.14. Within the BDI categories, there were statistically significant differences (p < 0.001), which were greater for the MS group. Depression is a dangerous factor for MS patients, being a trigger for a poorer quality of life.

Role of RGC-32 in multiple sclerosis and neuroinflammation – few answers and many questions

Recent advances in understanding the pathogenesis of multiple sclerosis (MS) have brought into the spotlight the major role played by reactive astrocytes in this condition. Response Gene to Complement (RGC)-32 is a gene induced by complement activation, growth factors, and cytokines, notably transforming growth factor β, that is involved in the modulation of processes such as angiogenesis, fibrosis, cell migration, and cell differentiation. Studies have uncovered the crucial role that RGC-32 plays in promoting the differentiation of Th17 cells, a subtype of CD4+ T lymphocytes with an important role in MS and its murine model, experimental autoimmune encephalomyelitis. The latest data have also shown that RGC-32 is involved in regulating major transcriptomic changes in astrocytes and in favoring the synthesis and secretion of extracellular matrix components, growth factors, axonal growth molecules, and pro-astrogliogenic molecules. These results suggest that RGC-32 plays a major role in driving reactive astrocytosis and the generation of astrocytes from radial glia precursors. In this review, we summarize recent advances in understanding how RGC-32 regulates the behavior of Th17 cells and astrocytes in neuroinflammation, providing insight into its role as a potential new biomarker and therapeutic target.

Emerging Role of Neuron-Glia in Neurological Disorders: At a Glance

Based on the diverse physiological influence, the impact of glial cells has become much more evident on neurological illnesses, resulting in the origins of many diseases appearing to be more convoluted than previously happened. Since neurological disorders are often random and unknown, hence the construction of animal models is difficult to build, representing a small fraction of people with a gene mutation. As a result, an immediate necessity is grown to work within in vitro techniques for examining these illnesses. As the scientific community recognizes cell-autonomous contributions to a variety of central nervous system illnesses, therapeutic techniques involving stem cells for treating neurological diseases are gaining traction. The use of stem cells derived from a variety of sources is increasingly being used to replace both neuronal and glial tissue. The brain's energy demands necessitate the reliance of neurons on glial cells in order for it to function properly. Furthermore, glial cells have diverse functions in terms of regulating their own metabolic activities, as well as collaborating with neurons via secreted signaling or guidance molecules, forming a complex network of neuron-glial connections in health and sickness. Emerging data reveals that metabolic changes in glial cells can cause morphological and functional changes in conjunction with neuronal dysfunction under disease situations, highlighting the importance of neuron-glia interactions in the pathophysiology of neurological illnesses. In this context, it is required to improve our understanding of disease mechanisms and create potential novel therapeutics. According to research, synaptic malfunction is one of the features of various mental diseases, and glial cells are acting as key ingredients not only in synapse formation, growth, and plasticity but also in neuroinflammation and synaptic homeostasis which creates critical physiological capacity in the focused sensory system. The goal of this review article is to elaborate state-of-the-art information on a few glial cell types situated in the central nervous system (CNS) and highlight their role in the onset and progression of neurological disorders.

NG2-glia crosstalk with microglia in health and disease

Neurodegenerative diseases are increasingly becoming a global problem. However, the pathological mechanisms underlying neurodegenerative diseases are not fully understood. NG2‐glia abnormalities and microglia activation are involved in the development and/or progression of neurodegenerative disorders, such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, and cerebrovascular diseases. In this review, we summarize the present understanding of the interaction between NG2‐glia and microglia in physiological and pathological states and discuss unsolved questions concerning their fate and potential fate. First, we introduce the NG2‐glia and microglia in health and disease. Second, we formulate the interaction between NG2‐glia and microglia. NG2‐glia proliferation, migration, differentiation, and apoptosis are influenced by factors released from the microglia. On the other hand, NG2‐glia also regulate microglia actions. We conclude that NG2‐glia and microglia are important immunomodulatory cells in the brain. Understanding the interaction between NG2‐glia and microglia will help provide a novel method to modulate myelination and treat neurodegenerative disorders.

Focus on the Role of the NLRP3 Inflammasome in Multiple Sclerosis: Pathogenesis, Diagnosis, and Therapeutics

Neuroinflammation is initiated with an aberrant innate immune response in the central nervous system (CNS) and is involved in many neurological diseases. Inflammasomes are intracellular multiprotein complexes that can be used as platforms to induce the maturation and secretion of proinflammatory cytokines and pyroptosis, thus playing a pivotal role in neuroinflammation. Among the inflammasomes, the nucleotide-binding oligomerization domain-, leucine-rich repeat- and pyrin domain-containing 3 (NLRP3) inflammasome is well-characterized and contributes to many neurological diseases, such as multiple sclerosis (MS), Alzheimer's disease (AD), and ischemic stroke. MS is a chronic autoimmune disease of the CNS, and its hallmarks include chronic inflammation, demyelination, and neurodegeneration. Studies have demonstrated a relationship between MS and the NLRP3 inflammasome. To date, the pathogenesis of MS is not fully understood, and clinical studies on novel therapies are still underway. Here, we review the activation mechanism of the NLRP3 inflammasome, its role in MS, and therapies targeting related molecules, which may be beneficial in MS.

Multiple Sclerosis Biomarker Candidates Revealed by Cell-Type-Specific Interactome Analysis

Multiple sclerosis (MS) is a demyelinating disorder that affects multiple regions of the central nervous system such as the brain, spinal cord, and optic nerves. Susceptibility to MS, as well as disease progression rates, displays marked patient-to-patient variability. To date, biomarkers that forecast differences in clinical phenotypes and outcomes have been limited. In this context, cell-type-specific interactome analyses offer important prospects and hope for novel diagnostics and therapeutics. We report here an original study using bioinformatic analysis of MS data sets that revealed interaction profiles as well as specific hub proteins in white matter (WM) and gray matter (GM) that appear critical for disease mechanisms. First, cell-type-specific interactome analyses suggested that while interactions within the WM were focused on oligodendrocytes, interactions within the GM were mostly neuron centric. Second, hub proteins such as APP, EGLN3, PTEN, and LRRK2 were identified to be differentially regulated in MS data sets. Lastly, a comparison of the brain and peripheral blood samples identified biomarker candidates such as NRGN, CRTC1, CDC42, and IFITM3 to be differentially expressed in different types of MS. These findings offer a unique cell-type-specific cell-to-cell interaction network in MS and identify potential biomarkers by comparative analysis of the brain and the blood transcriptomics. From a study design and methodology perspective, we suggest that the cell-type-specific interactome analysis is an important systems science frontier that might offer new insights on other neurodegenerative and brain disorders as well.

Role of Inner Ear Macrophages and Autoimmune/Autoinflammatory Mechanisms in the Pathophysiology of Inner Ear Disease

Macrophages play important roles in tissue homeostasis and inflammation. Recent studies have revealed that macrophages are dispersed in the inner ear and may play essential roles in eliciting an immune response. Autoinflammatory diseases comprise a family of immune-mediated diseases, some of which involve sensorineural hearing loss, indicating that similar mechanisms may underlie the pathogenesis of immune-mediated hearing loss. Autoimmune inner ear disease (AIED) is an idiopathic disorder characterized by unexpected hearing loss. Tissue macrophages in the inner ear represent a potential target for modulation of the local immune response in patients with AIED/autoinflammatory diseases. In this review, we describe the relationship between cochlear macrophages and the pathophysiology of AIED/autoinflammatory disease.

Effect of natalizumab treatment on the rate of No Evidence of Disease Activity in young adults with multiple sclerosis in relation to pubertal stage

Approximately 40% of young-onset multiple sclerosis (MS) patients experience breakthrough disease, which carries a high risk for long-term disability, and requires using therapies beyond traditional first-line agents. Despite the increasing use of newer disease-modifying treatments (DMTs) in this population, data are not available to guide the need for escalating DMTs and there is a scarcity of data on the effects of natalizumab in children and young adults with active disease. We performed a retrospective analysis of the rate of No Evidence of Disease Activity (NEDA), tolerability, and safety of natalizumab in a multi-center cohort of 36 children and young adults with highly active MS. All patients had active disease and initiated treatment with natalizumab. The primary endpoint was the rate of achieving NEDA-3 status, within two years of natalizumab treatment. To examine a possible effect of age on the outcome of treatment, outcomes were also analyzed by pre-pubertal (n = 13 children aged 9-13 years) and pubertal subgroups (n = 23 young adolescents aged 14-20 years). The NEDA-3 status of the pre-pubertal group was 92% in the first and second year and in the pubertal group - 96% in the first year and 92% in the second year. Natalizumab reduced the number and volume of brain lesions in both pre-pubertal and pubertal groups. Treatment was well-tolerated, only 8 patients (22.2%) had adverse events during the 2-year study period. Our analysis shows that natalizumab is effective and well-tolerated in pre-pubertal and pubertal MS patients.

Ocular manifestations of multiple sclerosis in patients from three countries: A Web-based survey

OBJECTIVE

This study evaluates the epidemiological characteristics, ophthalmological manifestations, and different therapeutic options available for patients with multiple sclerosis (MS) in China, Spain, and Cuba.

METHODS

A self-designed questionnaire was used to conduct a comparable descriptive cross-sectional study on patients with MS. The survey included patients' demographic data, ocular manifestations related to MS, and treatment methodology followed in the three countries. The online survey was designed using the Wenjuanxing survey platform, and a survey link was circulated through WhatsApp, WeChat, and emails. Quantitative data were expressed as mean and standard deviation, the Kruskal-Wallis test was used for non-parametric variables. Qualitative data were expressed as numerical and percentage. The chi-square test (χ²) was used to compare the group's response categories. The statistical difference was considered significant when p < 0.05.

RESULTS

The female-to-male ratio in all the three countries was 2-3:1, and relapsing-remitting MS (RRMS) was the most frequent in all three countries. Vision loss was slow and progressive in half of the patients from the three countries, with no significant differences (p = 0.524). A higher percentage of steroid treatment was observed in Chinese patients in comparison with the patients from other two countries (p < 0.001), and a similar trend was seen in the use of traditional medicines. Almost one-third of patients who did not receive any treatment recovered spontaneously in all the three countries (p = 0.097).

CONCLUSIONS

MS occurs more frequently in the relapsing-remitting clinical form and there is a clear female predominance. The first ocular crisis or clinical debut of MS is characterized by slow and progressive visual impairment, increasing and adding to other ocular manifestations during its evolutionary course. Spontaneous recovery of vision after an attack of optic neuritis in the course of MS is possible.

Linking immune-mediated damage to neurodegeneration in multiple sclerosis: could network-based MRI help?

Inflammatory demyelination characterizes the initial stages of multiple sclerosis, while progressive axonal and neuronal loss are coexisting and significantly contribute to the long-term physical and cognitive impairment. There is an unmet need for a conceptual shift from a dualistic view of multiple sclerosis pathology, involving either inflammatory demyelination or neurodegeneration, to integrative dynamic models of brain reorganization, where, glia-neuron interactions, synaptic alterations and grey matter pathology are longitudinally envisaged at the whole-brain level. Functional and structural MRI can delineate network hallmarks for relapses, remissions or disease progression, which can be linked to the pathophysiology behind inflammatory attacks, repair and neurodegeneration. Here, we aim to unify recent findings of grey matter circuits dynamics in multiple sclerosis within the framework of molecular and pathophysiological hallmarks combined with disease-related network reorganization, while highlighting advances from animal models (in vivo and ex vivo) and human clinical data (imaging and histological). We propose that MRI-based brain networks characterization is essential for better delineating ongoing pathology and elaboration of particular mechanisms that may serve for accurate modelling and prediction of disease courses throughout disease stages.

Nanosystems and exosomes as future approaches in treating multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system which leads to neurological dysfunctions and severe disabilities. MS pathology is characterised by damage of the blood-brain barrier and infiltration of autoreactive T cells that overactivate glial cells, thereby initiating neuroinflammation accompanied by the formation of demyelinating plaques and neurodegeneration. Clinical deficits in this multifactorial disease depend on the progression of myelin loss, the stage of inflammation, the status of axons and the activity of oligodendrocyte precursor cells (OPCs). Despite significant progress in the treatment of MS, current therapies remain limited and new approaches are highly desirable. Nanosystems based on liposomes and nanoparticles are among some of the more noteworthy therapeutic strategies being investigated. Applications of nanosystems alone or as drug carriers in animal models of MS have been found to successfully alleviate the symptoms of the disease and exert anti-inflammatory potential. Exosomes are a specific type of nanosystem based on nanometre-sized extracellular vesicles released by different cells which exhibit important healing features. Exosomes contain an array of anti-inflammatory and neuroprotective agents which may contribute to modulation of the immune system as well as promoting remyelination and tissue repair. In this review, opportunities to use nanosystems against progression of MS will be discussed in context of cell-specific pathologies associated with MS.

Histochemistry of microinfarcts in the mouse brain after injection of fluorescent microspheres into the common carotid artery

The mouse model of multiple cerebral infarctions, established by injecting fluorescent microspheres into the common carotid artery, is a recent development in animal models of cerebral ischemia. To investigate its effectiveness, mouse models of cerebral infarction were created by injecting fluorescent microspheres, 45–53 µm in diameter, into the common carotid artery. Six hours after modeling, fluorescent microspheres were observed directly through a fluorescence stereomicroscope, both on the brain surface and in brain sections. Changes in blood vessels, neurons and glial cells associated with microinfarcts were examined using fluorescence histochemistry and immunohistochemistry. The microspheres were distributed mainly in the cerebral cortex, striatum and hippocampus ipsilateral to the side of injection. Microinfarcts were found in the brain regions where the fluorescent microspheres were present. Here the lodged microspheres induced vascular and neuronal injury and the activation of astroglia and microglia. These histopathological changes indicate that this animal model of multiple cerebral infarctions effectively simulates the changes of various cell types observed in multifocal microinfarcts. This model is an effective, additional tool to study the pathogenesis of ischemic stroke and could be used to evaluate therapeutic interventions. This study was approved by the Animal Ethics Committee of the Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences (approval No. D2021-03-16-1) on March 16, 2021.

Astroglial and Microglial Purinergic P2X7 Receptor as a Major Contributor to Neuroinflammation during the Course of Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system that leads to the progressive disability of patients. A characteristic feature of the disease is the presence of focal demyelinating lesions accompanied by an inflammatory reaction. Interactions between autoreactive immune cells and glia cells are considered as a central mechanism underlying the pathology of MS. A glia-mediated inflammatory reaction followed by overproduction of free radicals and generation of glutamate-induced excitotoxicity promotes oligodendrocyte injury, contributing to demyelination and subsequent neurodegeneration. Activation of purinergic signaling, in particular P2X7 receptor-mediated signaling, in astrocytes and microglia is an important causative factor in these pathological processes. This review discusses the role of astroglial and microglial cells, and in particular glial P2X7 receptors, in inducing MS-related neuroinflammatory events, highlighting the importance of P2X7R-mediated molecular pathways in MS pathology and identifying these receptors as a potential therapeutic target.

Stem Cell Therapies for Progressive Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by demyelination and axonal degeneration. MS patients typically present with a relapsing-remitting (RR) disease course, manifesting as sporadic attacks of neurological symptoms including ataxia, fatigue, and sensory impairment. While there are several effective disease-modifying therapies able to address the inflammatory relapses associated with RRMS, most patients will inevitably advance to a progressive disease course marked by a gradual and irreversible accrual of disabilities. Therapeutic intervention in progressive MS (PMS) suffers from a lack of well-characterized biological targets and, hence, a dearth of successful drugs. The few medications approved for the treatment of PMS are typically limited in their efficacy to active forms of the disease, have little impact on slowing degeneration, and fail to promote repair. In looking to address these unmet needs, the multifactorial therapeutic benefits of stem cell therapies are particularly compelling. Ostensibly providing neurotrophic support, immunomodulation and cell replacement, stem cell transplantation holds substantial promise in combatting the complex pathology of chronic neuroinflammation. Herein, we explore the current state of preclinical and clinical evidence supporting the use of stem cells in treating PMS and we discuss prospective hurdles impeding their translation into revolutionary regenerative medicines.

Metabolic Control of Smoldering Neuroinflammation

Compelling evidence exists that patients with chronic neurological conditions, which includes progressive multiple sclerosis, display pathological changes in neural metabolism and mitochondrial function. However, it is unknown if a similar degree of metabolic dysfunction occurs also in non-neural cells in the central nervous system. Specifically, it remains to be clarified (i) the full extent of metabolic changes in tissue-resident microglia and infiltrating macrophages after prolonged neuroinflammation (e.g., at the level of chronic active lesions), and (ii) whether these alterations underlie a unique pathogenic phenotype that is amenable for therapeutic targeting. Herein, we discuss how cell metabolism and mitochondrial function govern the function of chronic active microglia and macrophages brain infiltrates and identify new metabolic targets for therapeutic approaches aimed at reducing smoldering neuroinflammation.

Involvement of microRNA-155 in the mechanism of electroacupuncture treatment effects on experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a neurodegenerative and demyelinating autoimmune disease mediated by autoreactive T cells that affects the central nervous system (CNS). Electroacupuncture (EA) has emerged as an alternative or supplemental treatment for MS, but the mechanism by which EA may alleviate MS symptoms is unresolved. Here, we examined the effects of EA at the Zusanli (ST36) acupoint on mice with experimental autoimmune encephalomyelitis (EAE), the predominant animal model of MS. The effects of EA on EAE emergence, inflammatory cell levels, proinflammatory cytokines, and spinal cord pathology were examined. EA treatment attenuated the EAE clinical score and associated spinal cord demyelination, while reducing the presence of proinflammatory cytokines in mononuclear cells (MNCs), downregulating microRNA (miR)-155, and upregulating the opioid peptide precursor proopiomelanocortin (POMC) in the CNS. Experiments in which cultured neurons were transfected with a miR-155 mimic or a miR-155 inhibitor further showed that the direct modulation of miR-155 levels could regulate POMC levels in neurons. In conclusion, the alleviation of EAE by EA is characterized by reduced proportions of Th1/Th17 cells and increased proportions of Th2 cells, POMC upregulation, and miR-155 downregulation, while miR-155 itself can suppress POMC expression. These results, support the hypothesis that the effects of EA on EAE may involve the downregulation of miR-155.

Ironing Out the Details: How Iron Orchestrates Macrophage Polarization

Iron fine-tunes innate immune responses, including macrophage inflammation. In this review, we summarize the current understanding about the iron in dictating macrophage polarization. Mechanistically, iron orchestrates macrophage polarization through several aspects, including cellular signaling, cellular metabolism, and epigenetic regulation. Therefore, iron modulates the development and progression of multiple macrophage-associated diseases, such as cancer, atherosclerosis, and liver diseases. Collectively, this review highlights the crucial role of iron for macrophage polarization, and indicates the potential application of iron supplementation as an adjuvant therapy in different inflammatory disorders relative to the balance of macrophage polarization.

Neural stem cells traffic functional mitochondria via extracellular vesicles

Neural stem cell (NSC) transplantation induces recovery in animal models of central nervous system (CNS) diseases. Although the replacement of lost endogenous cells was originally proposed as the primary healing mechanism of NSC grafts, it is now clear that transplanted NSCs operate via multiple mechanisms, including the horizontal exchange of therapeutic cargoes to host cells via extracellular vesicles (EVs). EVs are membrane particles trafficking nucleic acids, proteins, metabolites and metabolic enzymes, lipids, and entire organelles. However, the function and the contribution of these cargoes to the broad therapeutic effects of NSCs are yet to be fully understood. Mitochondrial dysfunction is an established feature of several inflammatory and degenerative CNS disorders, most of which are potentially treatable with exogenous stem cell therapeutics. Herein, we investigated the hypothesis that NSCs release and traffic functional mitochondria via EVs to restore mitochondrial function in target cells. Untargeted proteomics revealed a significant enrichment of mitochondrial proteins spontaneously released by NSCs in EVs. Morphological and functional analyses confirmed the presence of ultrastructurally intact mitochondria within EVs with conserved membrane potential and respiration. We found that the transfer of these mitochondria from EVs to mtDNA-deficient L929 Rho0 cells rescued mitochondrial function and increased Rho0 cell survival. Furthermore, the incorporation of mitochondria from EVs into inflammatory mononuclear phagocytes restored normal mitochondrial dynamics and cellular metabolism and reduced the expression of pro-inflammatory markers in target cells. When transplanted in an animal model of multiple sclerosis, exogenous NSCs actively transferred mitochondria to mononuclear phagocytes and induced a significant amelioration of clinical deficits. Our data provide the first evidence that NSCs deliver functional mitochondria to target cells via EVs, paving the way for the development of novel (a)cellular approaches aimed at restoring mitochondrial dysfunction not only in multiple sclerosis, but also in degenerative neurological diseases.

Toll-like receptor 2 and 4 antagonism for the treatment of experimental autoimmune encephalomyelitis (EAE)-related pain

Neuropathic pain is a major symptom of multiple sclerosis (MS) with up to 92% of patients reporting bodily pain, and 85% reporting pain severe enough to cause functional disability. None of the available therapeutics target MS pain. Toll-like receptors 2 and 4 (TLR2/TLR4) have emerged as targets for treating a wide array of autoimmune disorders, including MS, as well as having demonstrated success at suppressing pain in diverse animal models. The current series of studies tested systemic TLR2/TLR4 antagonists in males and females in a low-dose Myelin oligodendrocyte glycoprotein (MOG) experimental autoimmune encephalomyelitis (EAE) model, with reduced motor dysfunction to allow unconfounded testing of allodynia through 50+ days post-MOG. The data demonstrated that blocking TLR2/TLR4 suppressed EAE-related pain, equally in males and females; upregulation of dorsal spinal cord proinflammatory gene expression for TLR2, TLR4, NLRP3, interleukin-1β, IkBα, TNF-α and interleukin-17; and upregulation of dorsal spinal cord expression of glial immunoreactivity markers. In support of these results, intrathecal interleukin-1 receptor antagonist reversed EAE-induced allodynia, both early and late after EAE induction. In contrast, blocking TLR2/TLR4 did not suppress EAE-induced motor disturbances induced by a higher MOG dose. These data suggest that blocking TLR2/TLR4 prevents the production of proinflammatory factors involved in low dose EAE pathology. Moreover, in this EAE model, TLR2/TLR4 antagonists were highly effective in reducing pain, whereas motor impairment, as seen in high dose MOG EAE, is not affected.

Antigen-Specific Treatment Modalities in MS: The Past, the Present, and the Future

Antigen-specific therapy for multiple sclerosis may lead to a more effective therapy by induction of tolerance to a wide range of myelin-derived antigens without hampering the normal surveillance and effector function of the immune system. Numerous attempts to restore tolerance toward myelin-derived antigens have been made over the past decades, both in animal models of multiple sclerosis and in clinical trials for multiple sclerosis patients. In this review, we will give an overview of the current approaches for antigen-specific therapy that are in clinical development for multiple sclerosis as well provide an insight into the challenges for future antigen-specific treatment strategies for multiple sclerosis.

Intracisternal administration of tanshinone IIA-loaded nanoparticles leads to reduced tissue injury and functional deficits in a porcine model of ischemic stroke

Background

The absolute number of new stroke patients is annually increasing and there still remains only a few Food and Drug Administration (FDA) approved treatments with significant limitations available to patients. Tanshinone IIA (Tan IIA) is a promising potential therapeutic for ischemic stroke that has shown success in pre-clinical rodent studies but lead to inconsistent efficacy results in human patients. The physical properties of Tan-IIA, including short half-life and low solubility, suggests that Poly (lactic-co-glycolic acid) (PLGA) nanoparticle-assisted delivery may lead to improve bioavailability and therapeutic efficacy. The objective of this study was to develop Tan IIA-loaded nanoparticles (Tan IIA-NPs) and to evaluate their therapeutic effects on cerebral pathological changes and consequent motor function deficits in a pig ischemic stroke model.

Results

Tan IIA-NP treated neural stem cells showed a reduction in SOD activity in in vitro assays demonstrating antioxidative effects. Ischemic stroke pigs treated with Tan IIA-NPs showed reduced hemispheric swelling when compared to vehicle only treated pigs (7.85 ± 1.41 vs. 16.83 ± 0.62%), consequent midline shift (MLS) (1.72 ± 0.07 vs. 2.91 ± 0.36 mm), and ischemic lesion volumes (9.54 ± 5.06 vs. 12.01 ± 0.17 cm³) when compared to vehicle-only treated pigs. Treatment also lead to lower reductions in diffusivity (-37.30 ± 3.67 vs. -46.33 ± 0.73%) and white matter integrity (-19.66 ± 5.58 vs. -30.11 ± 1.19%) as well as reduced hemorrhage (0.85 ± 0.15 vs 2.91 ± 0.84 cm³) 24 h post-ischemic stroke. In addition, Tan IIA-NPs led to a reduced percentage of circulating band neutrophils at 12 (7.75 ± 1.93 vs. 14.00 ± 1.73%) and 24 (4.25 ± 0.48 vs 5.75 ± 0.85%) hours post-stroke suggesting a mitigated inflammatory response. Moreover, spatiotemporal gait deficits including cadence, cycle time, step time, swing percent of cycle, stride length, and changes in relative mean pressure were less severe post-stroke in Tan IIA-NP treated pigs relative to control pigs.

Conclusion

The findings of this proof of concept study strongly suggest that administration of Tan IIA-NPs in the acute phase post-stroke mitigates neural injury likely through limiting free radical formation, thus leading to less severe gait deficits in a translational pig ischemic stroke model. With stroke as one of the leading causes of functional disability in the United States, and gait deficits being a major component, these promising results suggest that acute Tan IIA-NP administration may improve functional outcomes and the quality of life of many future stroke patients.

MRI in Normal Myelination: A Pictorial Review

This article's primary goal is to provide an image-based review to paediatricians to gain insight into the typical appearance of myelin evolution. We briefly discuss the structure and development of myelination, the role of qualitative and quantitative MRI in myelin imaging, and provide an image-based review as a quick reference for understanding the pattern of myelination on MR imaging.

Disrupted Lipid Metabolism in Multiple Sclerosis: A Role for Liver X Receptors?

Multiple sclerosis (MS) is a chronic neurological disease driven by autoimmune, inflammatory and neurodegenerative processes leading to neuronal demyelination and subsequent degeneration. Systemic lipid metabolism is disturbed in people with MS, and lipid metabolic pathways are crucial to the protective process of remyelination. The lipid-activated transcription factors liver X receptors (LXRs) are important integrators of lipid metabolism and immunity. Consequently, there is a strong interest in targeting these receptors in a number of metabolic and inflammatory diseases, including MS. We have reviewed the evidence for involvement of LXR-driven lipid metabolism in the dysfunction of peripheral and brain-resident immune cells in MS, focusing on human studies, both the relapsing remitting and progressive phases of the disease are discussed. Finally, we discuss the therapeutic potential of modulating the activity of these receptors with existing pharmacological agents and highlight important areas of future research.

Comparison between cerebrospinal fluid and serum levels of myelin-associated glycoprotein, total antioxidant capacity, and 8-hydroxy-2'-deoxyguanosine in patients with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory disease characterized by demyelinated lesions in the brain, the spinal cord, and the optic nerve. It is one of the most common neurological disorders. In this study, serum and cerebrospinal fluid (CSF) levels of total antioxidant capacity (TAC), myelin-associated glycoprotein (MAG), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were investigated to determine their effects on MS.

MATERIALS AND METHOD

In this study, 25 serum and cerebrospinal samples from MS patients as a case group and 40 serum and CSF samples from healthy participants as a control group were collected and analyzed. Concentrations of TAC, MAG, and 8-OhdG were determined in the samples using a dedicated kit and relayed using the ELISA device.

RESULTS

The mean serum antibody levels of MAG and TAC were higher in the case group than the control group, although the difference in the MAG level was not significant (P > 0.05). However, the mean serum level of -8 OHdG was lower in the case group than the control group. Moreover, the mean levels of the evaluated biomarkers in the CSF samples were higher in the case group than in the control group. Still, the difference was only significant in terms of TAC levels (P < 0.05). Receiver operating characteristics curve analysis showed that the area under the curve was 0.71 and 0.69 for 8-OhdG and TAC serum levels, respectively, and 0.73 for both TAC and CSF levels, which was not significantly different from that in other biomarkers.

CONCLUSION

Elevated TAC levels in serum and CSF samples and 8-OhdG in serum samples may be associated with MS pathogenesis. However, further investigation is needed to consider these cases as a follow-up to the therapeutic goals or treatment process.

Air pollution as a contributor to the inflammatory activity of multiple sclerosis

OBJECTIVE

Air pollution has been recently identified as a risk factor for multiple sclerosis. Aim of this study was to investigate the immunological mechanism underlying the clinical association between air pollution, namely exposure to particulate matter 10 (PM10), and inflammatory activity of multiple sclerosis (MS) METHODS: Daily recording of PM10 was obtained by monitors depending on the residence of subjects. Expression of molecules involved in activation, adhesion, and migration of T lymphocytes were tested by flow cytometry in 57 MS patients and 19 healthy controls. We next assessed in vitro the effect of PM10 on expression of C-C chemokine receptors 6 (CCR6) by peripheral blood mononuclear cells (PBMCs), on cytokine production by monocyte-derived dendritic cells (mdDC), and on T cell polarization in PBMC/mdDC mixed cultures.

RESULTS

We identified a significant correlation between mean PM10 levels and expression of CCR6 CD4+ T circulating cells in MS patients. This was paralleled by the observation in vitro of a higher level of CCR6 expression on PBMC following treatment with increased doses of particulate matter. Moreover, in mdDC cultures, particulate matter induced the secretion by mdDC of Th17 polarizing IL1 beta, IL6, and IL23 and, in mdDC/PBMC mixed cultures, enhanced generation of IL17-producing T cells.

CONCLUSIONS

Ex vivo and in vitro studies support the pro-inflammatory role of PM in MS, by upregulating expression of CCR6 on circulating CD4+ T cells and inducing in innate immune cells the production of Th17 polarizing cytokines. Therefore, we speculate that in MS respiratory exposure to PM10 may induce the production in the lung of autoreactive Th17 lymphocytes and boost their migratory properties through the blood-brain barrier.

Emerging Role of Extracellular Vesicles in the Pathophysiology of Multiple Sclerosis

Extracellular vesicles (EVs) represent a new reality for many physiological and pathological functions as an alternative mode of intercellular communication. This is due to their capacity to interact with distant recipient cells, usually involving delivery of the EVs contents into the target cells. Intensive investigation has targeted the role of EVs in different pathological conditions, including multiple sclerosis (MS). MS is a chronic inflammatory and neurodegenerative disease of the nervous system, one of the main causes of neurological disability in young adults. The fine interplay between the immune and nervous systems is profoundly altered in this disease, and EVs seems to have a relevant impact on MS pathogenesis. Here, we provide an overview of both clinical and preclinical studies showing that EVs released from blood–brain barrier (BBB) endothelial cells, platelets, leukocytes, myeloid cells, astrocytes, and oligodendrocytes are involved in the pathogenesis of MS and of its rodent model experimental autoimmune encephalomyelitis (EAE). Most of the information points to an impact of EVs on BBB damage, on spreading pro-inflammatory signals, and altering neuronal functions, but EVs reparative function of brain damage deserves attention. Finally, we will describe recent advances about EVs as potential therapeutic targets and tools for therapeutic intervention in MS.

Profiles of cortical inflammation in multiple sclerosis by 11C-PBR28 MR-PET and 7 Tesla imaging

BACKGROUND

Neuroinflammation with microglia activation is thought to be closely related to cortical multiple sclerosis (MS) lesion pathogenesis.

OBJECTIVE

Using 11C-PBR28 and 7 Tesla (7T) imaging, we assessed in 9 relapsing-remitting multiple sclerosis (RRMS) and 10 secondary progressive multiple sclerosis (SPMS) patients the following: (1) microglia activation in lesioned and normal-appearing cortex, (2) cortical lesion inflammatory profiles, and (3) the relationship between neuroinflammation and cortical integrity.

METHODS

Mean 11C-PBR28 uptake was measured in focal cortical lesions, cortical areas with 7T quantitative T2* (q-T2*) abnormalities, and normal-appearing cortex. The relative difference in cortical 11C-PBR28 uptake between patients and 14 controls was used to classify cortical lesions as either active or inactive. Disease burden was investigated according to cortical lesion inflammatory profiles. The relation between q-T2* and 11C-PBR28 uptake along the cortex was assessed.

RESULTS

11C-PBR28 uptake was abnormally high in cortical lesions in RRMS and SPMS; in SPMS, tracer uptake was significantly increased also in normal-appearing cortex. 11C-PBR28 uptake and q-T2* correlated positively in many cortical areas, negatively in some regions. Patients with high cortical lesion inflammation had worse clinical outcome and higher intracortical lesion burden than patients with low inflammation.

CONCLUSION

11C-PBR28 and 7T imaging reveal distinct profiles of cortical inflammation in MS, which are related to disease burden.

Circulating endothelial progenitor cells during pregnancy in multiple sclerosis

Background

Endothelial progenitor cells (EPCs) have been shown to increase during physiological pregnancy and are believed to play a fundamental role in the process of placentation. Reduced levels of EPCs during pregnancy have been associated with preeclampsia and miscarriage. Women with multiple sclerosis (MS) are not at increased risk of preeclampsia nor of general adverse obstetric outcome, in contrast with some other autoimmune diseases.

Objective

The aim of this study was to evaluate circulating EPCs levels in pregnant patients with MS.

Methods

CD34+ and CD133+ were longitudinally detected by flow cytometry in the maternal plasma of 29 healthy controls and 9 MS patients and in the cord blood of their newborns.

Results

EPCs were affected by pregnancy with the same trend in both groups (CD34+ p = 0.0342; CD133+ p = 0.0347). EPCs during pregnancy were increased in MS (mean ± SD: CD34+ cells 0.038 ± 0.010; CD133+ 0.024 ± 0.009) with respect to healthy controls (mean ± SD: CD34+ cells 0.022 ± 0.006; CD133+ 0.016 ± 0.004), CD34+ p = 0.0004; CD133+ p = 0.0109. EPCs levels of the cord blood of MS patients' newborns mild correlated with maternal EPC levels at delivery (CD34+: spearman’s Rho 0.658, p = 0.054; CD133+: spearman’s Rho 0.758, p = 0.018).

Conclusions

This work identified increased circulating EPC levels during pregnancy, following the same trend both in MS patients and healthy controls. Despite the similar trend, the levels of circulating EPCs were significantly higher in MS patients with respect to the control population. A correlation was also found in MS patients between cord blood EPCs and circulating EPCs at delivery.

Electronic supplementary material

The online version of this article (10.1007/s10072-020-04648-3) contains supplementary material, which is available to authorized users.

Promises and Limitations of Neural Stem Cell Therapies for Progressive Multiple Sclerosis

Multiple disease-modifying medications with regulatory approval to treat multiple sclerosis (MS) are unable to prevent inflammatory tissue damage in the central nervous system (CNS), and none directly promote repair. Thus, there is an unmet clinical need for therapies that can arrest and reverse the persistent accumulation of disabilities associated with progressive forms of MS (P-MS). Preclinical research has revealed an unexpected ability of neural stem cell (NSC) therapies to provide neurotrophic support and inhibit detrimental host immune responses in vivo following transplantation into the chronically inflamed CNS. We discuss NSC transplantation as a promising therapy for P-MS, elaborate on the necessities of clinical trial validation and formalized usage guidelines, and caution about unscrupulous 'clinics' marketing unproven therapies to patients.

CBD Suppression of EAE Is Correlated with Early Inhibition of Splenic IFN-γ + CD8+ T Cells and Modest Inhibition of Neuroinflammation

In this study cannabidiol (CBD) was administered orally to determine its effects and mechanisms in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). We hypothesized that 75 mg/kg of oral CBD given for 5 days after initiation of disease would reduce EAE severity through suppression of either the early peripheral immune or late neuroimmune response. EAE was induced in C57BL/6 mice at two different magnitudes, and peripheral inflammatory and neuroinflammatory responses were measured at days 3, 10, and 18. Th1, Th17, Tc1, Tc17, Tregs, and myeloid derived suppressor cells (MDSC) were identified from the lymph nodes and spleens of each mouse to determine if CBD altered the suppressor cell or inflammatory cell populations in secondary lymphoid tissues. Additionally, neuroinflammation was identified in brain and spinal cord tissues using various immunohistochemical techniques and flow cytometry. Early treatment of EAE with oral CBD reduced clinical disease at the day 18 timepoint which correlated with a significant decrease in the percentage of MOG_35-55 specific IFN-γ producing CD8⁺ T cells in the spleen at day 10. Analysis of both T cell infiltration and lesion size within the spinal cord also showed a moderate reduction in neuroinflammation within the central nervous system (CNS). These results provide evidence that oral CBD suppressed the peripheral immune response that precedes neuroinflammation; however, analysis of the neuroinflammatory endpoints also suggest that the modest reduction in neuroinflammation was only partially responsible for CBD's neuroprotective capability. Graphical Abstract CBD was administered orally for the first 5 days following initiation of EAE. CBD attenuated clinical disease, and we found that CBD suppressed IFN-γ producing CD8⁺ T cells in the spleen at day 10. There was also modest suppression of neuroinflammation. Together these data demonstrate that early, oral administration of CBD protected mice from disease, but the modest effects on neuroinflammation suggest other mechanisms participate in CBD's neuroprotective effect in EAE.