Growing role of S100B protein as a putative therapeutic target for neurological- and nonneurological-disorders

A novel HDAC8 inhibitor H7E exerts retinoprotective effects against glaucomatous injury via ameliorating aberrant Müller glia activation and oxidative stress

Glaucoma is considered a neurodegenerative disease characterized by progressive visual field defects that may lead to blindness. Although controlling intraocular pressure (IOP) is the mainstay of glaucoma treatment, some glaucoma patients have unmet needs due to unclear pathogenic mechanisms. Recently, there has been growing evidence that neuroinflammation is a potential target for the development of novel antiglaucoma agents. In this study, we investigated the protective effects and cellular mechanisms of H7E, a novel small molecule inhibits HDAC8, using in vitro and in vivo glaucoma-like models. Importantly, H7E mitigated extracellular MMP-9 activity and MCP-1 levels in glutamate- or S100B-stimulated reactive Müller glia. In addition, H7E inhibited the upregulation of inflammation- and proliferation-related signaling pathways, particularly the ERK and JNK MAPK pathways. Under conditions of oxidative damage, H7E prevents retinal cell death and reduces extracellular glutamate released from stressed Müller glia. In a mouse model of NMDA-induced retinal degeneration, H7E alleviated functional and structural defects within the inner retina as assessed by electroretinography and optical coherence tomography. Our results demonstrated that the newly identified compound H7E protects against glaucoma damage by specifically targeting HDAC8 activity in the retina. This protective effect is attributed to the inhibition of Müller glial activation and the prevention of retinal cell death caused by oxidative stress.

The Multifaceted S100B Protein: A Role in Obesity and Diabetes?

The S100B protein is abundant in the nervous system, mainly in astrocytes, and is also present in other districts. Among these, the adipose tissue is a site of concentration for the protein. In the light of consistent research showing some associations between S100B and adipose tissue in the context of obesity, metabolic disorders, and diabetes, this review tunes the possible role of S100B in the pathogenic processes of these disorders, which are known to involve the adipose tissue. The reported data suggest a role for adipose S100B in obesity/diabetes processes, thus putatively re-proposing the role played by astrocytic S100B in neuroinflammatory/neurodegenerative processes.

Astroglial S100B Secretion Is Mediated by Ca2+ Mobilization from Endoplasmic Reticulum: A Study Using Forskolin and DMSO as Secretagogues

S100B, a homodimeric Ca2+-binding protein, is produced and secreted by astrocytes, and its extracellular levels have been used as a glial marker in brain damage and neurodegenerative and psychiatric diseases; however, its mechanism of secretion is elusive. We used primary astrocyte cultures and calcium measurements from real-time fluorescence microscopy to investigate the role of intracellular calcium in S100B secretion. In addition, the dimethyl sulfoxide (DMSO) effect on S100B was investigated in vitro and in vivo using Wistar rats. We found that DMSO, a widely used vehicle in biological assays, is a powerful S100B secretagogue, which caused a biphasic response of Ca2+ mobilization. Our data show that astroglial S100B secretion is triggered by the increase in intracellular Ca2+ and indicate that this increase is due to Ca2+ mobilization from the endoplasmic reticulum. Also, blocking plasma membrane Ca2+ channels involved in the Ca2+ replenishment of internal stores decreased S100B secretion. The DMSO-induced S100B secretion was confirmed in vivo and in ex vivo hippocampal slices. Our data support a nonclassic vesicular export of S100B modulated by Ca2+, and the results might contribute to understanding the mechanism underlying the astroglial release of S100B.

Phytocannabinoids Reduce Inflammation of Primed Macrophages and Enteric Glial Cells: An In Vitro Study

Intestinal inflammation is mediated by a subset of cells populating the intestine, such as enteric glial cells (EGC) and macrophages. Different studies indicate that phytocannabinoids could play a possible role in the treatment of inflammatory bowel disease (IBD) by relieving the symptoms involved in the disease. Phytocannabinoids act through the endocannabinoid system, which is distributed throughout the mammalian body in the cells of the immune system and in the intestinal cells. Our in vitro study analyzed the putative anti-inflammatory effect of nine selected pure cannabinoids in J774A1 macrophage cells and EGCs triggered to undergo inflammation with lipopolysaccharide (LPS). The anti-inflammatory effect of several phytocannabinoids was measured by their ability to reduce TNFα transcription and translation in J774A1 macrophages and to diminish S100B and GFAP secretion and transcription in EGCs. Our results demonstrate that THC at the lower concentrations tested exerted the most effective anti-inflammatory effect in both J774A1 macrophages and EGCs compared to the other phytocannabinoids tested herein. We then performed RNA-seq analysis of EGCs exposed to LPS in the presence or absence of THC or THC-COOH. Transcriptomic analysis of these EGCs revealed 23 differentially expressed genes (DEG) compared to the treatment with only LPS. Pretreatment with THC resulted in 26 DEG, and pretreatment with THC-COOH resulted in 25 DEG. To evaluate which biological pathways were affected by the different phytocannabinoid treatments, we used the Ingenuity platform. We show that THC treatment affects the mTOR and RAR signaling pathway, while THC-COOH mainly affects the IL6 signaling pathway.

Cellular and Molecular Pathophysiology of Traumatic Brain Injury: What Have We Learned So Far?

Traumatic brain injury (TBI) is one of the leading causes of long-lasting morbidity and mortality worldwide, being a devastating condition related to the impairment of the nervous system after an external traumatic event resulting in transitory or permanent functional disability, with a significant burden to the healthcare system. Harmful events underlying TBI can be classified into two sequential stages, primary and secondary, which are both associated with breakdown of the tissue homeostasis due to impairment of the blood-brain barrier, osmotic imbalance, inflammatory processes, oxidative stress, excitotoxicity, and apoptotic cell death, ultimately resulting in a loss of tissue functionality. The present study provides an updated review concerning the roles of brain edema, inflammation, excitotoxicity, and oxidative stress on brain changes resulting from a TBI. The proper characterization of the phenomena resulting from TBI can contribute to the improvement of care, rehabilitation and quality of life of the affected people.

Biochemical and Anthropometric Parameters for the Early Recognition of the Intrauterine Growth Restriction and Preterm Neonates at Risk of Impaired Neurodevelopment

BACKGROUND

S100B and Tau are implicated with both brain growth and injury. Their urinary levels in 30-to-40-day-old full-term, preterm, IUGR, and preterm-IUGR subjects were measured to investigate their possible relationship with future delayed neurodevelopment.

METHODS

Values were related to the neuro-behavioral outcome at two years of age, as well as to brain volumes and urinary NGF assessed at the same postnatal time point.

RESULTS

Using the Griffiths III test, cognitive and motor performances were determined to establish subgroups characterized by either normal or impaired neuro-behavior. The latter included preterm, IUGR, and preterm-IUGR individuals who exhibited significantly higher and lower S100B and Tau levels, respectively, along with markedly reduced cerebral volumes and urinary NGF, as previously demonstrated. Contrary to NGF, however, Tau and S100B displayed a weak correlation with brain volumes.

CONCLUSIONS

Delayed cognitive and motor performances observed in two-year-old preterm and IUGR-born individuals were also found to be associated with anomalous urinary levels of S100B and Tau, assessed at 30-40 days of the postnatal period, and their changes did not correlate with brain growth. Thus, our data suggests that, in addition to cerebral volumes and NGF, urinary S100B and Tau can also be considered as valuable parameters for the early detection of future neurodevelopmental abnormalities.

The S100B Protein: A Multifaceted Pathogenic Factor More Than a Biomarker

S100B is a calcium-binding protein mainly concentrated in astrocytes in the nervous system. Its levels in biological fluids are recognized as a reliable biomarker of active neural distress, and more recently, mounting evidence points to S100B as a Damage-Associated Molecular Pattern molecule, which, at high concentration, triggers tissue reactions to damage. S100B levels and/or distribution in the nervous tissue of patients and/or experimental models of different neural disorders, for which the protein is used as a biomarker, are directly related to the progress of the disease. In addition, in experimental models of diseases such as Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, multiple sclerosis, traumatic and vascular acute neural injury, epilepsy, and inflammatory bowel disease, alteration of S100B levels correlates with the occurrence of clinical and/or toxic parameters. In general, overexpression/administration of S100B worsens the clinical presentation, whereas deletion/inactivation of the protein contributes to the amelioration of the symptoms. Thus, the S100B protein may be proposed as a common pathogenic factor in different disorders, sharing different symptoms and etiologies but appearing to share some common pathogenic processes reasonably attributable to neuroinflammation.

Integrative analysis of gene expression and DNA methylation to identify biomarkers of non-genital warts induced by low-risk human papillomaviruses infection

Background

Human papillomaviruses have been shown to dysregulate the gene expression and DNA methylation profiles of their host cells over the course of infection. However, there is a lack of information on the impact of low-risk HPV infection and wart formation on host cell's expression and methylation patterns. Therefore, the objective of this study is to analyse the genome and methylome of common warts using an integrative approach.

Methods

In the present study, gene expression (GSE136347) and methylation (GSE213888) datasets of common warts were obtained from the GEO database. Identification of the differentially expressed and differentially methylated genes was carried out using the RnBeads R package and the edgeR Bioconductor package. Next, functional annotation of the identified genes was obtained using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). Network construction and analyses of the gene-gene, protein-protein, and signaling interactions of the differentially expressed and differentially methylated genes was performed using the GeneMANIA web interface, the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and the Signaling Network Open Resource 2.0 (SIGNOR 2.0), respectively. Lastly, significant hub genes were identified using the Cytoscape application CytoHubba.

Results

A total of 276 genes were identified as differentially expressed and differentially methylated in common warts, with 52% being upregulated and hypermethylated. Functional enrichment analysis identified extracellular components as the most enriched annotations, while network analyses identified ELN, ITGB1, TIMP1, MMP2, LGALS3, COL1A1 and ANPEP as significant hub genes.

Conclusions

To the best knowledge of the authors, this is the first integrative study to be carried out on non-genital warts induced by low-risk HPV types. Future studies are required to re-validate the findings in larger populations using alternative approaches.

Brain damage serum biomarkers induced by COVID-19 in patients from northeast Brazil

Neurological symptoms have been often reported in COVID-19 disease. In the present study, we evaluated brain damage associated with the increase of serum levels of neurological biomarkers S100B and neuron-specific enolase (NSE) induced by SARS-CoV-2 infection, in a population from Northeastern Brazil. Thirty-six healthy control (G1) individuals and 141 patients with confirmed COVID-19 were enrolled in this study. Positive-COVID-19 patients were divided into two groups according to the severity of illness by the National Institute of Health (NIH) criteria, 76 patients with mild symptoms for COVID-19 and (G2) and 65 with acute respiratory conditions requiring supplemental oxygenation via intensive care unit (ICU) admission (G3). A follow-up study was conducted with 23 patients from G2 14 (D14) and 21 (D21) days after the onset of symptoms. Serum levels of NSE and S100B were measured using the enzyme-linked immunoassay method (ELISA). Results revealed a significant positive association between G3 patients and S100B serum expression (p = 0.0403). The serum levels of NSE were also significantly enhanced in the G3 group compared to the control (p < 0.0001) and G2 group (p < 0.0001). In addition, clinical features such as symptoms and oxygenation status were not correlated with NSE or S100B serum expression. The follow-up study demonstrated a decrease over time (21 days) in NSE serum expression (p < 0.0001). These results suggest that brain damage is followed by acute virus exposure, with no long-term effects. Future work examining COVID-19 recovery will shed light on chronic neurological damage of SARS-CoV-2 infection.

S100B Expression Plays a Crucial Role in Cytotoxicity, Reactive Oxygen Species Generation and Nitric Oxide Synthase Activation Induced by Amyloid β-Protein in an Astrocytoma Cell Line

S100B is an astrocytic cytokine that has been shown to be involved in several neurodegenerative diseases. We used an astrocytoma cell line (U373 MG) silenced for S100B, and stimulated it with amyloid beta-peptide (Aβ) as a known paradigm factor for astrocyte activation, and showed that the ability of the cell (including the gene machinery) to express S100B is a prerequisite for inducing reactive astrocytic features, such as ROS generation, NOS activation and cytotoxicity. Our results showed that control astrocytoma cell line exhibited overexpression of S100B after Aβ treatment, and subsequently cytotoxicity, increased ROS generation and NOS activation. In contrast, cells silenced with S100B were essentially protected, consistently reducing cell death, significantly decreasing oxygen radical generation and nitric oxide synthase activity. The conclusive aim of the present study was to show a causative linkage between the cell expression of S100B and induction of astrocyte activation processes, such as cytotoxicity, ROS and NOS activation.

Administration of Kainic Acid Differentially Alters Astrocyte Markers and Transiently Enhanced Phospho-tau Level in Adult Rat Hippocampus

Kainic acid (KA), an analogue of the excitatory neurotransmitter glutamate, when administered systemically can trigger seizures and neuronal loss in a manner that mirrors the neuropathology of human mesial temporal lobe epilepsy (mTLE), which affects ∼50 million people globally. Evidence suggests that changes in astrocytes which precede neuronal damage play an important role in the degeneration of neurons and/or development of seizures in TLE pathogenesis. Additionally, a role for microtubule associated tau protein, involved in various neurodegenerative diseases including Alzheimer's disease, has also been suggested in the development of seizure and/or neurodegeneration in TLE pathogenesis. At present, possible alterations of different subtypes of astrocytes and their association, if any, with tau protein in TLE remain unclear. In this study, we evaluated alterations of different subtypes of astrocytes and phospho-/cleaved-tau levels in KA-treated rat model of TLE. Our results reveal that levels/expression of various astrocyte markers such as GFAP, vimentin, S100B, Aldh1L1, but not GS, are increased in the hippocampus of KA-treated rats. The levels/expression of both A1(C3+) and A2(S100A10+)-like astrocytes are also increased in KA-treated rats. Concurrently, the total (Tau1 and Tau5) and phospho-tau (AT270 and PHF1) levels are transiently enhanced following KA administration. Furthermore, the level/expression of cleaved-tau, which is apparent in a subset of GFAP-, S100B- and A2-positive astrocytes, are increased in KA-treated rats. These results, taken together, suggest a differential role for various astrocytic subpopulations and tau protein in the development of seizure and/or loss of neurons in KA model of TLE and possibly in human mTLE pathogenesis.

S100B Affects Gut Microbiota Biodiversity

This in vivo study in mice addresses the relationship between the biodiversity of the microbiota and the levels of S100B, a protein present in enteroglial cells, but also in foods such as milk. A positive significant correlation was observed between S100B levels and Shannon values, which was reduced after treatment with Pentamidine, an inhibitor of S100B function, indicating that the correlation was influenced by the modulation of S100B activity. Using the bootstrap average method based on the distribution of the S100B concentration, three groups were identified, exhibiting a significant difference between the microbial profiles. Operational taxonomic units, when analyzed by SIMPER analysis, showed that genera regarded to be eubiotic were mainly concentrated in the intermediate group, while genera potentially harboring pathobionts often appeared to be more concentrated in groups where the S100B amounts were very low or high. Finally, in a pilot experiment, S100B was administered orally, and the microbial profiles appeared to be modified accordingly. These data may open novel perspectives involving the possibility of S100B-mediated regulation in the intestinal microbiota.

Differential proteomic profile of lumbar and ventricular cerebrospinal fluid

BACKGROUND

Pathological cerebral conditions may manifest in altered composition of the cerebrospinal fluid (CSF). Although diagnostic CSF analysis seeks to establish pathological disturbances in the brain proper, CSF is generally sampled from the lumbar compartment for reasons of technical ease and ethical considerations. We here aimed to compare the molecular composition of CSF obtained from the ventricular versus the lumbar CSF compartments to establish a relevance for employing lumbar CSF as a proxy for the CSF bathing the brain tissue.

METHODS

CSF was collected from 46 patients with idiopathic normal pressure hydrocephalus (iNPH) patients during their diagnostic workup (lumbar samples) and in connection with their subsequent CSF diversion shunt surgery (ventricular samples). The mass-spectrometry-based proteomic profile was determined in these samples and in addition, selected biomarkers were quantified with ELISA (S100B, neurofilament light (NfL), amyloid-β (Aβ₄₀, Aβ₄₂), and total tau (T-tau) and phosphorylated tau (P-tau) forms). The latter analysis was extended to include paired porcine samples obtained from the lumbar compartment and the cerebromedullary cistern closely related to the ventricles.

RESULTS

In total 1231 proteins were detected in the human CSF. Of these, 216 distributed equally in the two CSF compartments, whereas 22 were preferentially (or solely) present in the ventricular CSF and four in the lumbar CSF. The selected biomarkers of neurodegeneration and Alzheimer's disease displayed differential distribution, some with higher (S100B, T-tau, and P-tau) and some with lower (NfL, Aβ₄₀, Aβ₄₂) levels in the ventricular compartment. In the porcine samples, all biomarkers were most abundant in the lumbar CSF.

CONCLUSIONS

The overall proteomic profile differs between the ventricular and the lumbar CSF compartments, and so does the distribution of clinically employed biomarkers. However, for a range of CSF proteins and biomarkers, one can reliably employ lumbar CSF as a proxy for ventricular CSF if or a lumbar/cranial index for the particular molecule has been established. It is therefore important to verify the compartmental preference of the proteins or biomarkers of interest prior to extrapolating from lumbar CSF to that of the ventricular fluid bordering the brain.

Transcriptomes of Clusterin- and S100B-transfected neuronal cells elucidate protective mechanisms against hypoxia and oxidative stress in the hooded seal (Cystophora cristata) brain

BACKGROUND

The hooded seal (Cystophora cristata) exhibits impressive diving skills and can tolerate extended durations of asphyxia, hypoxia and oxidative stress, without suffering from irreversible neuronal damage. Thus, when exposed to hypoxia in vitro, neurons of fresh cortical and hippocampal tissue from hooded seals maintained their membrane potential 4-5 times longer than neurons of mice. We aimed to identify the molecular mechanisms underlying the intrinsic neuronal hypoxia tolerance. Previous comparative transcriptomics of the visual cortex have revealed that S100B and clusterin (apolipoprotein J), two stress proteins that are involved in neurological disorders characterized by hypoxic conditions, have a remarkably high expression in hooded seals compared to ferrets. When overexpressed in murine neuronal cells (HN33), S100B and clusterin had neuroprotective effects when cells were exposed to hypoxia. However, their specific roles in hypoxia have remained largely unknown.

METHODS

In order to shed light on potential molecular pathways or interaction partners, we exposed HN33 cells transfected with either S100B, soluble clusterin (sCLU) or nuclear clusterin (nCLU) to normoxia, hypoxia and oxidative stress for 24 h. We then determined cell viability and compared the transcriptomes of transfected cells to control cells. Potential pathways and upstream regulators were identified via Gene Ontology (GO) and Ingenuity Pathway Analysis (IPA).

RESULTS

HN33 cells transfected with sCLU and S100B demonstrated improved glycolytic capacity and reduced aerobic respiration at normoxic conditions. Additionally, sCLU appeared to enhance pathways for cellular homeostasis to counteract stress-induced aggregation of proteins. S100B-transfected cells sustained lowered energy-intensive synaptic signaling. In response to hypoxia, hypoxia-inducible factor (HIF) pathways were considerably elevated in nCLU- and sCLU-transfected cells. In a previous study, S100B and sCLU decreased the amount of reactive oxygen species and lipid peroxidation in HN33 cells in response to oxidative stress, but in the present study, these functional effects were not mirrored in gene expression changes.

CONCLUSIONS

sCLU and S100B overexpression increased neuronal survival by decreasing aerobic metabolism and synaptic signaling in advance to hypoxia and oxidative stress conditions, possibly to reduce energy expenditure and the build-up of deleterious reactive oxygen species (ROS). Thus, a high expression of CLU isoforms and S100B is likely beneficial during hypoxic conditions.

Synthesis and Bioactivity Evaluation of a Novel 1,2,4-Oxadiazole Derivative in vitro and in 3×Tg Mice

Aim

Alzheimer’s disease (AD) is the most common neurodegenerative disease whose patients suffered from cognitive impairments. In our study, a novel 1,2,4-Oxadiazole derivative wyc-7-20 was synthesized, which showed low cytotoxicity and potent neuroprotective effect at the cellular level. Improved cognitive impairments, β-amyloid (Aβ) clearance, and tau pathological phenotypes were detected in transgenic animal models after wyc-7-20 treatment. Reversed expressions in AD-related genes were also detected. The results demonstrated wyc-7-20 was potent in AD therapy.

Purpose

The pathological complexity of AD increased difficulties in medical research. To explore a new potential medical treatment for AD, a novel 1,2,4-Oxadiazole derivative (wyc-7-20) was designed, synthesized to explore the application in this study.

Materials and Methods

Human neuroblastoma (SH-SY5Y) cells and human hepatocellular carcinoma (HepG2) cells were used to detect median lethal dose (LD50). H₂O₂ and Aβ_1–42 oligomers (AβOs) were respectively, added into SH-SY5Y cells to detect anti-ROS (reactive oxygen species) and anti-AβOs effects of wyc-7-20. 3×Tg mice were administered with wyc-7-20, and then Y maze test and Morris water maze (MWM) test were applied to detect cognitive improvements. Brain tissue samples were subsequently collected and analyzed using different techniques.

Results

wyc-7-20 showed low cytotoxicity and potent neuroprotective effect at the cellular level. Improved cognitive impairments, Aβ clearance, and tau pathological phenotypes were detected in transgenic animal models after wyc-7-20 treatment. Reversed expressions in AD-related genes were also detected.

Conclusion

wyc-7-20 was potent in AD therapy.

Early predictors of abnormal MRI patterns in asphyxiated infants: S100B protein urine levels

OBJECTIVES

The early detection and stratification of asphyxiated infants at higher risk for impaired neurodevelopment is challenging. S100B protein is a well-established biomarker of brain damage, but lacks conclusive validation according to the "gold standard" methodology for hypoxic-ischemic encephalopathy (HIE) prognostication, i.e. brain MRI. The aim of the present study was to investigate the predictive role of urinary S100B concentrations, assessed in a cohort of HIE infants receiving therapeutic hypothermia (TH), compared to brain MRI.

METHODS

Assessment of urine S100B concentrations was performed by immunoluminometric assay at first void and at 4, 8, 12, 16, 20, 24, 48, 72, 96, 108 and 120-h after birth. Neurologic evaluation, routine laboratory parameters, amplitude-integrated electroencephalography, and cerebral ultrasound were performed according to standard protocols. Brain MRI was performed at 7-10 days of life.

RESULTS

Overall, 74 HIE neonates receiving TH were included in the study. S100B correlated, already at first void, with the MRI patterns with higher concentrations in infants with the most severe MRI lesions.

CONCLUSIONS

High S100B urine levels soon after birth constitute trustable predictors of brain injury as confirmed by MRI. Results support the reliability of S100B in clinical daily practice and open the way to its inclusion in the panel of parameters used for the selection of cases suitable for TH treatment.

Interferon-β Activity Is Affected by S100B Protein

Interferon-β (IFN-β) is a pleiotropic cytokine secreted in response to various pathological conditions and is clinically used for therapy of multiple sclerosis. Its application for treatment of cancer, infections and pulmonary diseases is limited by incomplete understanding of regulatory mechanisms of its functioning. Recently, we reported that IFN-β activity is affected by interactions with S100A1, S100A4, S100A6, and S100P proteins, which are members of the S100 protein family of multifunctional Ca²⁺-binding proteins possessing cytokine-like activities (Int J Mol Sci. 2020;21(24):9473). Here we show that IFN-β interacts with one more representative of the S100 protein family, the S100B protein, involved in numerous oncological and neurological diseases. The use of chemical crosslinking, intrinsic fluorescence, and surface plasmon resonance spectroscopy revealed IFN-β binding to Ca²⁺-loaded dimeric and monomeric forms of the S100B protein. Calcium depletion blocks the S100B–IFN-β interaction. S100B monomerization increases its affinity to IFN-β by 2.7 orders of magnitude (equilibrium dissociation constant of the complex reaches 47 pM). Crystal violet assay demonstrated that combined application of IFN-β and S100B (5–25 nM) eliminates their inhibitory effects on MCF-7 cell viability. Bioinformatics analysis showed that the direct modulation of IFN-β activity by the S100B protein described here could be relevant to progression of multiple oncological and neurological diseases.

S100B Protein as a Therapeutic Target in Multiple Sclerosis: The S100B Inhibitor Arundic Acid Protects from Chronic Experimental Autoimmune Encephalomyelitis

S100B is an astrocytic protein behaving at high concentration as a damage-associated molecular pattern molecule. A direct correlation between the increased amount of S100B and inflammatory processes has been demonstrated, and in particular, the inhibitor of S100B activity pentamidine has been shown to ameliorate clinical scores and neuropathologic-biomolecular parameters in the relapsing-remitting experimental autoimmune encephalomyelitis mouse model of multiple sclerosis. This study investigates the effect of arundic acid (AA), a known inhibitor of astrocytic S100B synthesis, in the chronic experimental autoimmune encephalomyelitis, which is another mouse model of multiple sclerosis usually studied. By the daily evaluation of clinical scores and neuropathologic-molecular analysis performed in the spinal cord, we observed that the AA-treated group showed lower severity compared to the vehicle-treated mice, particularly in the early phase of disease onset. We also observed a significant reduction of astrocytosis, demyelination, immune infiltrates, proinflammatory cytokines expression and enzymatic oxidative reactivity in the AA-treated group. Overall, our results reinforce the involvement of S100B in the development of animal models of multiple sclerosis and propose AA targeting the S100B protein as a focused potential drug to be considered for multiple sclerosis treatment.

Calcium in Neuronal and Glial Response to Axotomy

Neurotrauma assumes an instant or delayed disconnection of axons (axotomy), which affects not only neurons, but surrounding glia as well. Not only mechanically injured glia near the site of disconnection, especially transection, is subjected to the damage, but also glia that is remote from the lesion site. Glial cells, which surround the neuronal body, in turn, support neuron survival, so there is a mutual protection between neuron and glia. Calcium signaling is a central mediator of all post-axotomy events, both in neuron and glia, playing a critical role in their survival/regeneration or death/degeneration. The involvement of calcium in post-axotomy survival of the remote, mechanically intact glia is poorly studied. The purpose of this review is to sum up the calcium-involving mechanisms in responses of neurons and glial cells to axotomy to show their importance and to give some suggestions for future research of remote glia in this context.