Molecular Pharmacology and Novel Potential Therapeutic Applications of Fingolimod

The janus face of astrocytes in multiple sclerosis: Balancing protection and pathology

Multiple sclerosis (MS) is a chronic autoimmune disorder characterized by demyelination and neurodegeneration in the central nervous system (CNS), predominantly affecting young adults with a notable female predominance. While the pathogenesis of MS involves complex interactions between peripheral immune cells and CNS glia, astrocytes-the most abundant glial cells-play a dual role in disease progression. Traditionally classified into pro-inflammatory A1 and neuroprotective A2 phenotypes, recent single-cell and spatial transcriptomics reveal that human astrocytes exhibit a continuum of states beyond this binary paradigm. In MS, reactive astrocytes contribute to neurotoxicity by disrupting the blood-brain barrier (BBB), promoting glutamate excitotoxicity, and presenting antigens to autoreactive T cells. Conversely, they also support repair through neurotrophic factor release (e.g., BDNF, CNTF) and remyelination. Emerging therapies like dimethyl fumarate (DMF) and fingolimod modulate astrocyte reactivity, targeting oxidative stress and sphingosine-1-phosphate receptors to mitigate neuroinflammation. However, challenges persist in translating murine A1/A2 concepts to human MS, as human astrocytes display heterogeneous, context-dependent responses influenced by regional microenvironments and disease stages. Advanced techniques, including spatial multi-omics, highlight astrocyte-microglia crosstalk and metabolic reprogramming as key drivers of MS pathology. This review synthesizes current evidence on astrocyte heterogeneity, their Janus-faced roles in MS, and the therapeutic potential of astrocyte-targeted strategies, advocating for precision approaches that account for human-specific astrocyte biology. Future research must priorities human-centric biomarkers and dynamic modelling to bridge the gap between experimental findings and clinical applications.

In vitro investigation of the toxicological mechanisms of Fingolimod (S)-phosphate in HEPG2 cells

Fingolimod (FTY720) was the first sphingosine-1-phosphate (S1P) receptor modulator approved by the US Food and Drug Administration for the treatment of multiple sclerosis. The active form, FTY720 (S)-P, acts as a potent agonist of the S1P receptor, leading to its downregulation on the cell surface, reduced activity, and termination of sphingosine-dependent intracellular signalling. Elevated hepatic enzyme levels, clinically significant liver injury, and acute liver failure have been observed in patients treated with FTY720 (S)-P, which requires additional monitoring. This is the first study to investigate the mechanisms underlying the hepatotoxicity of FTY720 (S)-P and represents an important contribution to elucidating its toxicity mechanisms in the human hepatocellular carcinoma cell line HepG2. Following a 72-h exposure, standard methods were used to evaluate specific targets, including cytotoxic effect potentials, mitochondrial parameters, and changes of the antioxidant enzyme levels. FTY720 (S)-P exposure resulted in time- and dose-dependent decreases in cell viability, mitochondrial membrane potential, and ATP levels, as well as the induction of oxidative stress. The complex toxic profile observed for FTY720 (S)-P is hypothesized to originate from its interaction with sirtuin proteins, particularly SIRT3 and SIRT5. It was also complemented with molecular docking simulations to assess the compound's targeting potential by analysing its interaction profile and binding pose within the active sites of both proteins. The results supported the proposed hypothesis, demonstrating an optimal fitting profile and favourable interaction behaviour within the binding pockets of the SIRT3 and SIRT5 enzymes.

Inflammation, Anti-inflammatory Interventions, and Post-stroke Cognitive Impairment: a Systematic Review and Meta-analysis of Human and Animal Studies

The pathophysiology and treatment of post-stroke cognitive impairment (PSCI) are not clear. Stroke triggers an inflammatory response, which might affect synapse function and cognitive status. We performed a systematic review and meta-analysis to assess whether patients with PSCI have increased levels of inflammatory markers and whether anti-inflammatory interventions in animals decrease PSCI. We systematically searched PubMed, EMBASE, and PsychInfo for studies on stroke. For human studies, we determined the standardized mean difference (SMD) on the association between PSCI and markers of inflammation. For animal studies, we determined the SMD of post-stroke cognitive outcome after an anti-inflammatory intervention. Interventions were grouped based on proposed mechanism of action. In patients, the SMD of inflammatory markers for those with versus those without PSCI was 0.46 (95% CI 0.18; 0.76; I2 = 92%), and the correlation coefficient between level of inflammation and cognitive scores was - 0.25 (95% CI - 0.34; - 0.16; I2 = 75%). In animals, the SMD of cognition for those treated with versus those without anti-inflammatory interventions was 1.43 (95% CI 1.12; 1.74; I2 = 83%). The largest effect sizes in treated animals were for complement inhibition (SMD = 1.94 (95% CI 1.50; 2.37), I2 = 51%) and fingolimod (SMD = 2.1 (95% CI 0.75; 3.47), I2 = 81%). Inflammation is increased in stroke survivors with cognitive impairment and is negatively correlated with cognitive functioning. Anti-inflammatory interventions seem to improve cognitive functioning in animals. Complement inhibition and fingolimod are promising therapies on reducing PSCI.

Identification of Six Cerebrospinal Fluid Metabolites Causally Associated with Anorexia Nervosa Risk: A Mendelian Randomization Analysis

Anorexia nervosa (AN) is a severe psychiatric disorder characterized by substantial heritability and a high mortality rate among psychiatric disorders. While cerebrospinal fluid (CSF) metabolomics has emerged as a novel approach to investigating central nervous system pathologies, its specific causal relationship with anorexia nervosa remains to be fully elucidated. Using genome-wide association study (GWAS) summary statistics for human CSF metabolites and AN information from publicly available datasets, we performed a two-sample Mendelian randomization (MR) analysis using the inverse-variance weighted (IVW) method as the primary approach, complemented by sensitivity analyses. Through a comprehensive analysis of 338 CSF metabolites, we identified six metabolites with significant causal relationships with AN risk. 1-stearoyl-2-linoleoyl-gpc (18:0/18:2) (OR = 1.09, 95% CI 1.00-1.18) and alpha-tocopherol (OR = 1.36, 95% CI 1.00-1.83) showed positive associations, increasing AN risk. Conversely, sphingomyelin (d18:1/20:0, d16:1/22:0) (OR = 0.86, 95% CI 0.77-0.95), 2,3-dihydroxy-2-methylbutyrate (OR = 0.92, 95% CI 0.86-0.98), N-acetylhistidine (OR = 0.92, 95% CI 0.86-0.98), and oxalate (ethanedioate) (OR = 0.83, 95% CI 0.73-0.94) had protective effects, reducing AN risk. Sensitivity analyses showed no evidence of horizontal pleiotropy or heterogeneity in the MR results. An MR directionality test and a Steiger filtering test confirmed the absence of reverse causality, thereby substantiating the robustness of our findings. These findings suggest that these CSF metabolites could serve as potential biomarkers for early AN detection and highlight novel therapeutic targets, potentially improving diagnosis and intervention strategies for this challenging disorder.

Fingolimod Suppresses NLRP3 Inflammasome Activation and Alleviates Oxidative Stress in Traumatic Brain Injury-Induced Acute Lung Injury

Background

Acute lung injury (ALI) is a serious yet common complication in patients with traumatic brain injury (TBI), often associated with poor prognosis. The development of TBI-induced ALI is closely associated with excessive oxidative stress and NLRP3 inflammasome activation. Fingolimod, an immunomodulatory agent, has been reported to attenuate inflammatory responses, restore blood-brain barrier integrity, reduce cerebral edema, and mitigate associated neurological deficits.

Objective

This study aimed to investigate the mechanistic role of NLRP3 inflammasome activation in TBI-induced ALI and to evaluate the therapeutic potential of fingolimod in targeting this inflammatory pathway.

Results

A rat TBI model was established using the classical free-fall method, and animals were treated with fingolimod (0.5 or 1 mg/kg) daily for three days. The TBI model rats presented with clear signs of histopathological pulmonary damage, an increase in the permeability of capillaries in the lung, and pulmonary edema that coincided with significantly increased NLRP3, caspase-1, and ASC expression in lung tissue samples. This overexpression of NLRP3 inflammasome machinery resulted in the release of IL-1β. Fingolimod treatment, however, reversed all of these effects such that it suppressed NLRP3 activity and normalized levels of IL-1β, leading to the alleviation of inflammation. In line with these results, LPS and nigericin (NLRP3 agonist)-treated NR8383 cells treated using fingolimod exhibited reductions in reactive oxygen species production and NLRP3 inflammasome activation.

Conclusion

These findings suggest that NLRP3 inflammasome activation and oxidative stress are key mediators of TBI-induced ALI. Fingolimod exerts protective effects against this condition by inhibiting NLRP3 inflammasome activation, highlighting its potential as a therapeutic agent for TBI-associated pulmonary complications.

Glycyrrhizin as a potential disease-modifying therapy for epilepsy: insights into targeting pyroptosis to exert neuroprotective and anticonvulsant effects

Background

For patients with epilepsy, antiseizure medication remains the primary treatment; however, it is ineffective in approximately 30% of cases. These patients experience progressive neuronal damage and poor outcomes. Therefore, there is an urgent need for disease-modifying therapy (DMT) that targets the pathogenesis of epilepsy. Glycyrrhizin has shown potential as a DMT in epilepsy due to its multiple targets and diverse mechanisms. Previous studies suggest that glycyrrhizin may regulate key processes involved in epilepsy pathogenesis, such as neuroinflammation and cell death, but its effects on pyroptosis have not been reported.

Methods

This study employed bioinformatics techniques to identify potential molecular targets for glycyrrhizin in epilepsy treatment and then validated using a kainic acid-induced status epilepticus mouse model.

Results

Glycyrrhizin treatment significantly prolonged seizure latency, reduced seizure duration, and alleviated neuronal damage in the status epilepticus mouse model. Molecular experiments indicated that glycyrrhizin may regulate pyroptosis through mediation of the high mobility group box 1 (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway.

Conclusion

Glycyrrhizin exerts neuroprotective and anticonvulsant effects in epilepsy by regulating pyroptosis via the HMGB1/TLR4/NF-κB signaling pathway, offering novel insights into its potential as a DMT for epilepsy.

Sex-dependent efficacy of sphingosine-1-phosphate receptor agonist FTY720 in mitigating Huntington's disease

Huntington's disease (HD) is a debilitating neurodegenerative disorder characterized by severe motor deficits, cognitive decline and psychiatric disturbances. An early and significant morphological hallmark of HD is the activation of astrocytes triggered by mutant huntingtin, leading to the release of inflammatory mediators. Fingolimod (FTY), an FDA-approved sphingosine-1-phosphate (S1P) receptor agonist is used to treat multiple sclerosis (MS), a neuroinflammatory disease, and has shown therapeutic promise in other neurological conditions. Our study aimed to investigate the therapeutic potential of FTY for treating HD by utilizing a well-characterized mouse model of HD (zQ175dn) and wild-type littermates. The study design included a crossover, long-term oral treatment with 1 mg/kg to 2 mg/kg FTY from the age of 15-46 weeks (n = 128). Different motor behavior and physiological parameters were assessed throughout the study. The findings revealed that FTY rescued disease-related body weight loss in a sex-dependent manner, indicating its potential to regulate metabolic disturbances and to counteract neurodegenerative processes in HD. FTY intervention also rescued testicular atrophy, restored testis tissue structure in male mice suggesting a broader impact on peripheral tissues affected by huntingtin pathology. Histological analyses of the brain revealed delayed accumulation of activated astrocytes contributing to the preservation of the neural microenvironment by reducing neuroinflammation. The extent of FTY-related disease improvement was sex-dependent. Motor functions and body weight improved mostly in female mice with sustained estrogen levels, whereas males had to compensate for the ongoing, disease-related testis atrophy and the loss of androgen production. Our study underscores the beneficial therapeutic effects of FTY on HD involving endogenous steroid hormones and their important anabolic effects. It positions FTY as a promising candidate for therapeutic interventions targeting various aspects of HD pathology. Further studies are needed to fully evaluate its therapeutic potential in patients.

Fingolimod Inhibits C6 Rat Glioma Proliferation and Migration, Induces Sub-G1 Cell Cycle Arrest, Mitochondrial and Extrinsic Apoptosis In Vitro and Reduces Tumour Growth In Vivo

Glioblastoma multiforme (GBM), the most prevalent brain tumour, is universally fatal. GBM cells exhibit cell cycle disruption and treatment resistance, remarking an urgent need for newer treatments. Fingolimod, a sphingosine-1-phosphate receptor modulator, has been reported to have anti-cancer effects. This study investigated the therapeutic potentials of fingolimod in rat C6 cells and pursued the involved mechanism(s). Cell survival, proliferation, migration, and morphology of fingolimod-treated C6 cells were evaluated using MTT, soft-agar colony formation, wound-healing, and Giemsa staining assays. Apoptosis was investigated through acridine orange/ethidium bromide (AO/EB) and annexin V staining, and flow cytometry analysed the cell cycle. Quantitative reverse transcription PCR and western blotting were used to evaluate gene and protein expressions. An intracranial C6 rat model validated the anti-tumour effect of fingolimod. Fingolimod significantly reduced the survival and colonies of the C6 cells and delayed their gap closure. Cell shrinkage coupled with AO/EB and PI staining of the fingolimod-treated cells indicated apoptosis, subsequently confirmed by measuring the expression levels of the candidate genes involved in apoptosis and cell cycle, such as Bax/Bcl2, P53, Cytochrome C and Caspases 9/3, Fas, Fadd, Tnfrsf1a, Cdkn1a, and Ccnd1, at RNA and protein levels, indicating both extrinsic and mitochondrial apoptosis and cell cycle arrest at sub-G1 phase in fingolimod-treated cells. Furthermore, treating rats bearing intracranial C6 tumours with fingolimod led to significant suppression of intracranial tumour growth. Based on our findings, cell cycle arrest and apoptosis contribute to fingolimod antitumor effects.

Glial modulators as novel therapeutics for comorbid pain and opioid use disorder

Chronic pain and opioid use disorder (OUD) are major public health problems, with rising opioid-related overdose deaths linked to increased opioid prescriptions for pain management. Novel treatment approaches for these commonly comorbid disorders are needed. Growing evidence supports a role for glial activation for both chronic pain and substance use disorders, including OUD. This review provides an overview of glial modulators as a novel treatment approach for comorbid pain and OUD. We aim to synthesize clinical studies investigating the efficacy of glial modulators in treating these comorbid disorders. We conducted a literature search of PubMed and Google Scholar databases in October 2023 to identify relevant clinical trials. The included studies varied in terms of patient population, study methodology and outcomes assessed, and were often limited by small sample sizes and other methodological issues. Additionally, several glial modulators have yet to be studied for chronic pain and OUD. Despite these limitations, these studies yielded positive signals that merit further investigation. Both chronic pain and OUD remain significant public health problems, with many treatment challenges. Glial modulators continue to hold promise as novel therapeutics for comorbid pain and OUD, given positive indications that they can improve pain measures, and reduce addiction-related outcomes. As our understanding of the mechanisms underlying the contributions of glial modulators to pain and addiction behaviours deepens, we will be better equipped to identify more specific therapeutic targets for chronic pain and OUD.

Fingolimod, a sphingosine-1-phosphate receptor modulator, prevents neonatal bronchopulmonary dysplasia and subsequent airway remodeling in a murine model

Neonatal bronchopulmonary dysplasia (BPD) is associated with alveolar simplification and airway remodeling. Airway remodeling leads to deformation of airways characterized by peribronchial collagen deposition and hypertrophy of airway smooth muscle, which contribute to the narrowing of airways. Poorly developed lungs contribute to reduced lung function that deteriorates with the passage of time. We have earlier shown that sphingosine kinase 1 (SPHK 1)/sphingosine-1-phosphate (S1P)/S1P receptor1 (S1PR1) signaling plays a role in the pathogenesis of BPD. In this study, we investigated the role of fingolimod or FTY720, a known S1PR1 modulator approved for the treatment of multiple sclerosis in the treatment of BPD. Fingolimod promotes the degradation of S1PR1 by preventing its recycling, thus serving as the equivalent of an inhibitor. Exposure of neonatal mice to hyperoxia enhanced the expression of S1PR1 in both airways and alveoli as compared with normoxia. This increased expression of S1PR1 in the airways persisted into adulthood, accompanied by airway remodeling and airway hyperreactivity (AHR) after neonatal hyperoxia. Intranasal fingolimod at a much lower dose compared with the intraperitoneal route of administration during neonatal hyperoxia improved alveolarization in neonates and reduced airway remodeling and AHR in adult mice associated with improved lung function. The intranasal route was not associated with the lymphopenia seen with the intraperitoneal route of administration of the drug. An increase in S1PR1 expression in the airways was associated with an increase in the expression of enzyme lysyl oxidase (LOX) in the airways following hyperoxia, which was suppressed by fingolimod. This association warrants further investigation.NEW & NOTEWORTHY The role of the S1P receptor1 modulator, fingolimod, as an FDA-approved drug in preventing the recurrence of multiple sclerosis is established. Fingolimod prevented bronchopulmonary dysplasia (BPD) and its sequela of airway remodeling in a neonatal murine model. This protection was associated with the downregulation of lysyl oxidase signaling pathway. Fingolimod could be repurposed for the therapy of BPD.

Isolation and Characterization of the Cyanobacterial Macrolide Glycoside Moorenaside, an Anti-Inflammatory Analogue of Aurisides Targeting the Keap1/Nrf2 Pathway

A new 14-membered ring brominated macrolide glycoside, named moorenaside (1), was discovered from a marine cyanobacterial sample collected from Shands Key in Florida. The structure of 1 was established by analysis of spectroscopic data including its relative configuration. The absolute configuration was inferred from optical rotation data and comparison with related compounds. The structure of 1 features an α,β-unsaturated carbonyl system, which is also found in aurisides. The presence of this motif in 1 prompted us to evaluate its effect on Keap1/Nrf2 signaling, a cytoprotective pathway culminating in the activation of antioxidant genes activated upstream by the cysteine alkylation of Keap1. Moorenaside exhibited moderate ARE luciferase activity at 32 μM. Due to the established crosstalk between Nrf2 and NF-κB pathways, we investigated the anti-inflammatory effects of 1 in LPS-induced mouse macrophages (RAW264.7 cells), a commonly used model for inflammation. Moorenaside significantly upregulated Nqo1 (Nrf2 target gene) and downregulated iNos (NF-κB target gene) at 32 μM by 5.0- and 2.5-fold, respectively, resulting in a significant reduction of nitric oxide (NO) levels. Furthermore, we performed RNA-sequencing and demonstrated the transcriptional activity of 1 on a global level and identified canonical pathways and upstream regulators involved in inflammation, immune response, and certain oxidative-stress-underlying diseases such as multiple sclerosis and chronic kidney disease.

Therapeutic Potential of Fingolimod on Psychological Symptoms and Cognitive Function in Neuropsychiatric and Neurological Disorders

Neuropsychiatric and neurological disorders pose a significant global health burden, highlighting the need for innovative therapeutic approaches. Fingolimod (FTY720), a common drug to treat multiple sclerosis, has shown promising efficacy against various neuropsychiatric and neurological disorders. Fingolimod exerts its neuroprotective effects by targeting multiple cellular and molecular processes, such as apoptosis, oxidative stress, neuroinflammation, and autophagy. By modulating Sphingosine-1-Phosphate Receptor activity, a key regulator of immune cell trafficking and neuronal function, it also affects synaptic activity and strengthens memory formation. In the hippocampus, fingolimod decreases glutamate levels and increases GABA levels, suggesting a potential role in modulating synaptic transmission and neuronal excitability. Taken together, fingolimod has emerged as a promising neuroprotective agent for neuropsychiatric and neurological disorders. Its broad spectrum of cellular and molecular effects, including the modulation of apoptosis, oxidative stress, neuroinflammation, autophagy, and synaptic plasticity, provides a comprehensive therapeutic approach for these debilitating conditions. Further research is warranted to fully elucidate the mechanisms of action of fingolimod and optimize its use in the treatment of neuropsychiatric and neurological disorders.

Pathway analysis of peripheral blood CD8+ T cell transcriptome shows differential regulation of sphingolipid signaling in multiple sclerosis and glioblastoma

Multiple sclerosis (MS) and glioblastoma (GBM) are CNS diseases in whose development and progression immune privilege is intimately important, but in a relatively opposite manner. Maintenance and strengthening of immune privilege have been shown to be an important mechanism in glioblastoma immune evasion, while the breakdown of immune privilege leads to MS initiation and exacerbation. We hypothesize that molecular signaling pathways can be oppositely regulated in peripheral blood CD8+ T cells of MS and glioblastoma patients at a transcriptional level. We analyzed publicly available data of the peripheral blood CD8+ T cell MS vs. control (MSvsCTRL) and GBM vs. control (GBMvsCTRL) differentially expressed gene (DEG) contrasts with Qiagen's Ingenuity pathway analysis software (IPA). We have identified sphingolipid signaling pathway which was significantly downregulated in the GBMvsCTRL and upregulated in the MSvsCTRL. As the pathway is important for the CD8+ T lymphocytes CNS infiltration, this result is in line with our previously stated hypothesis. Comparing publicly available lists of differentially expressed serum exosomal miRNAs from MSvsCTRL and GBMvsCTRL contrasts, we have identified that hsa-miR-182-5p has the greatest potential effect on sphingolipid signaling regarding the number of regulated DEGs in the GBMvsCTRL contrast, while not being able to find any relevant potential sphingolipid signaling target transcripts in the MSvsCTRL contrast. We conclude that the sphingolipid signaling pathway is a top oppositely regulated pathway in peripheral blood CD8+ T cells from GBM and MS, and might be crucial for the differences in CNS immune privilege maintenance of investigated diseases, but further experimental research is necessary.

Beneficial Effect of Fingolimod in a Lafora Disease Mouse Model by Preventing Reactive Astrogliosis-Derived Neuroinflammation and Brain Infiltration of T-lymphocytes

Lafora disease (LD; OMIM#254780) is a rare, devastating, and fatal form of progressive myoclonus epilepsy that affects young adolescents and has no treatment yet. One of the hallmarks of the disease is the accumulation of aberrant poorly branched forms of glycogen (polyglucosans, PGs) in the brain and peripheral tissues. The current hypothesis is that this accumulation is causative of the pathophysiology of the disease. Another hallmark of LD is the presence of neuroinflammation. We have recently reported the presence of reactive glia-derived neuroinflammation in LD mouse models and defined the main inflammatory pathways that operate in these mice, mainly TNF and IL-6 signaling pathways. In addition, we described the presence of infiltration of peripheral immune cells in the brain parenchyma, which could cooperate and aggravate the neuroinflammatory landscape of LD. In this work, we have checked the beneficial effect of two compounds with the capacity to ameliorate neuroinflammation and reduce leukocyte infiltration into the brain, namely fingolimod and dimethyl fumarate. Our results indicate a beneficial effect of fingolimod in reducing reactive astrogliosis-derived neuroinflammation and T-lymphocyte infiltration, which correlated with the improved behavioral performance of the treated Epm2b-/- mice. On the contrary, dimethyl fumarate, although it was able to reduce reactive astrogliosis, was less effective in preventing neuroinflammation and T-lymphocyte infiltration and in modifying behavioral tests.

N-Containing triterpenoid saponins from Mussaenda densiflora and identification of heinsiagenin A as a potent immunosuppressant

Eleven triterpenoid saponins, including five new compounds, which were named densiflorasides A - E (1 - 5), were isolated from aerial parts of Mussaenda densiflora (Rubiaceae). Their structures were elucidated based on spectroscopic and single-crystal X-ray diffraction analyses and chemical methods. All the isolated compounds and the aglycone heinsiagenin A were evaluated for their immunosuppressive and antiosteoclastogenic activities in vitro. Compounds 6 - 8 and heinsiagenin A inhibited osteoclastogenesis, with IC50 values ranging from 8.24 to 17.7 µM. Furthermore, compounds 3, 6 - 8, and heinsiagenin A significantly inhibited T-cell proliferation, with IC50 values ranging from 2.56 to 8.60 µM, and compounds 3 - 5 and 11 inhibited the proliferation of B lymphocytes, with IC50 values ranging from 1.29 to 8.49 µM. Further in vivo experiments indicated that heinsiagenin A could significantly attenuate IMQ-induced psoriasis and DSS-induced colitis in mice.

Potential adverse events associated with sphingosine-1-phosphate (S1P) receptor modulators in patients with multiple sclerosis: an analysis of the FDA adverse event reporting system (FAERS) database

Objective

Sphingosine-1-phosphate receptor (S1PR) modulators have recently attracted increasing attention for the treatment of multiple sclerosis (MS). Despite their preference in the clinic, multiple adverse events (AEs) continue to be reported every year. This study aimed to investigate the potential AEs as well as related important medical events (IMEs) signal associated with S1PR modulators, including fingolimod, siponimod and ozanimod in a real-world study using the FDA Adverse Event Reporting System (FAERS) database.

Methods

All data were collected from the FAERS database, spanning from the fourth quarter of 2010(2010Q4) to the second quarter of 2023 (2023Q2). Potential AE and IME signals of S1PR modulators were identified based on a disproportionality analysis using the reporting odds ratio (ROR), proportional reporting ratio (PRR), and the bayesian confidence propagation neural network of information components (IC).

Results

Overall, 276,436 reports of fingolimod, 20,972 reports of siponimod and 10,742 reports of ozanimod were analyzed from the FAERS database. Among reports, females were more prone to develop AEs (73.71% for females vs. 23.21% for males), and more than 50% of patients suffered from AEs were between 18 and 64 years. Subsequently, we investigated the top 20 AEs associated with the signal strength of S1PR modulators at the preferred term (PT) level, and identified 31 (8 vs. 11 vs. 12, respectively) unlabeled risk signals such as thrombosis, uterine disorder and reproductive system and breast disorders. Furthermore, we discovered that the S1PR modulator reported variations in the possible IMEs, and that the IMEs associated with ocular events were reported frequently. It's interesting to note that infection and malignancy are prominent signals with both fingolimod and siponimod in the top 20 PTs related to mortality reports.

Conclusion

The present investigation highlights the possible safety risks associated with S1PR modulators. The majority of AEs are generally consistent with previous studies and are mentioned in the prescribing instructions, however, several unexpected AE signals have also been observed. Ozanimod showed the lowest signal intensity and a better safety profile than the other S1PR modulators. Due to the short marketing time of drugs and the limitations of spontaneous reporting database, further research is required to identify potential AEs related to S1PR modulators.

Senotherapeutic Peptide 14 Suppresses Th1 and M1 Human T Cell and Monocyte Subsets In Vitro

Inflammation contributes to the onset and exacerbation of numerous age-related diseases, often manifesting as a chronic condition during aging. Given that cellular senescence fosters local and systemic inflammation, senotherapeutic interventions could potentially aid in managing or even reducing inflammation. Here, we investigated the immunomodulatory effects of the senotherapeutic Peptide 14 (Pep 14) in human peripheral blood mononuclear cells (PBMCs), monocytes, and macrophages. We found that, despite failing to significantly influence T cell activation and proliferation, the peptide promoted a Th2/Treg gene expression and cytokine signature in PBMCs, characterized by increased expression of the transcription factors GATA3 and FOXP3, as well as the cytokines IL-4 and IL-10. These observations were partially confirmed through ELISA, in which we observed increased IL-10 release by resting and PHA-stimulated PBMCs. In monocytes from the U-937 cell line, Pep 14 induced apoptosis in lipopolysaccharide (LPS)-stimulated cells and upregulated IL-10 expression. Furthermore, Pep 14 prevented LPS-induced activation and promoted an M2-like polarization in U-937-derived macrophages, evidenced by decreased expression of M1 markers and increased expression of M2 markers. We also showed that the conditioned media from Pep 14-treated macrophages enhanced fibroblast migration, indicative of a functional M2 phenotype. Taken together, our findings suggest that Pep 14 modulates immune cell function towards an anti-inflammatory and regenerative phenotype, highlighting its potential as a therapeutic intervention to alleviate immunosenescence-associated dysregulation.

Neuroinflammation and Epilepsy: From Pathophysiology to Therapies Based on Repurposing Drugs

Neuroinflammation and epilepsy are different pathologies, but, in some cases, they are so closely related that the activation of one of the pathologies leads to the development of the other. In this work, we discuss the three main cell types involved in neuroinflammation, namely (i) reactive astrocytes, (ii) activated microglia, and infiltration of (iii) peripheral immune cells in the central nervous system. Then, we discuss how neuroinflammation and epilepsy are interconnected and describe the use of different repurposing drugs with anti-inflammatory properties that have been shown to have a beneficial effect in different epilepsy models. This review reinforces the idea that compounds designed to alleviate seizures need to target not only the neuroinflammation caused by reactive astrocytes and microglia but also the interaction of these cells with infiltrated peripheral immune cells.

Prodrugs as empowering tools in drug discovery and development: recent strategic applications of drug delivery solutions to mitigate challenges associated with lead compounds and drug candidates

The delivery of a drug to a specific organ or tissue at an efficacious concentration is the pharmacokinetic (PK) hallmark of promoting effective pharmacological action at a target site with an acceptable safety profile. Sub-optimal pharmaceutical or ADME profiles of drug candidates, which can often be a function of inherently poor physicochemical properties, pose significant challenges to drug discovery and development teams and may contribute to high compound attrition rates. Medicinal chemists have exploited prodrugs as an informed strategy to productively enhance the profiles of new chemical entities by optimizing the physicochemical, biopharmaceutical, and pharmacokinetic properties as well as selectively delivering a molecule to the site of action as a means of addressing a range of limitations. While discovery scientists have traditionally employed prodrugs to improve solubility and membrane permeability, the growing sophistication of prodrug technologies has enabled a significant expansion of their scope and applications as an empowering tool to mitigate a broad range of drug delivery challenges. Prodrugs have emerged as successful solutions to resolve non-linear exposure, inadequate exposure to support toxicological studies, pH-dependent absorption, high pill burden, formulation challenges, lack of feasibility of developing solid and liquid dosage forms, first-pass metabolism, high dosing frequency translating to reduced patient compliance and poor site-specific drug delivery. During the period 2012-2022, the US Food and Drug Administration (FDA) approved 50 prodrugs, which amounts to 13% of approved small molecule drugs, reflecting both the importance and success of implementing prodrug approaches in the pursuit of developing safe and effective drugs to address unmet medical needs.

Fingolimod exerts neuroprotection by regulating S1PR1 mediated BNIP3-PINK1-Parkin dependent mitophagy in rotenone induced mouse model of Parkinson's disease

The motor impairments brought on by the loss of dopaminergic neurons in the substantia nigra are the most well-known symptoms of Parkinson's disease (PD). It is believed that dopaminergic neurons are especially vulnerable to mitochondrial malfunction. For the maintenance of mitochondrial integrity, selective autophagic removal of dysfunctional mitochondria via mitophagy primarily regulated by PINK1/Parkin pathway is essential. Moreover, newer studies also implicate the role of phospholipid metabolism, such as that of Sphingosine-1-phosphate (S1P) as a contributor to PD. S1P receptors have been reported to influence mitochondrial function in neurodegenerative diseases. Fingolimod (FTY720), an S1P receptor-1 modulator has been proven effective in PD but its regulation of mitophagy in PD is still elusive. In this study, the neuroprotective effect of FTY720 by modulating mitophagy, has been explored against rotenone (ROT) induced neurotoxicity in in-vivo. The animals were randomly divided into 5 groups namely, Normal Control (NC); Disease control (DC): ROT (1.5 mg/kg); Low dose (LD): ROT + FTY720 (0.5 mg/kg); High dose (HD): ROT + FTY720 (1 mg/kg) and Vehicle control (VC): 1 % DMSO. ROT was administered through i.p. and FTY720 through p.o. for 21 days. At the end of the study, various neurobehavioral studies (rotarod test and actimeter), western blot techniques, and immunofluorescence studies were performed. FTY720 restored the neurobehavioural functions and protein expression of PINK1, Parkin and BNIP3 in ROT-induced PD mice. The results obtained in our study suggest that FTY720 has a neuroprotective effect in ROT-induced mice model of PD via PINK1-Parkin mediated mitophagy.

Multiple Sclerosis: New Insights into Molecular Pathogenesis and Novel Platforms for Disease Treatment

BACKGROUND

Multiple sclerosis (MS), a chronic inflammatory disorder, affects the central nervous system via myelin degradation. The cause of MS is not fully known, but during recent years, our knowledge has deepened significantly regarding the different aspects of MS, including etiology, molecular pathophysiology, diagnosis and therapeutic options. Myelin basic protein (MBP) is the main myelin protein that accounts for maintaining the stability of the myelin sheath. Recent evidence has revealed that MBP citrullination or deamination, which is catalyzed by Ca2+ dependent peptidyl arginine deiminase (PAD) enzyme leads to the reduction of positive charge, and subsequently proteolytic cleavage of MBP. The overexpression of PAD2 in the brains of MS patients plays an essential role in new epitope formation and progression of the autoimmune disorder. Some drugs have recently entered phase III clinical trials with promising efficacy and will probably obtain approval in the near future. As different therapeutic platforms develop, finding an optimal treatment for each individual patient will be more challenging.

AIMS

This review provides a comprehensive insight into MS with a focus on its pathogenesis and recent advances in diagnostic methods and its present and upcoming treatment modalities.

CONCLUSION

MS therapy alters quickly as research findings and therapeutic options surrounding MS expand. McDonald's guidelines have created different criteria for MS diagnosis. In recent years, ever-growing interest in the development of PAD inhibitors has led to the generation of many reversible and irreversible PAD inhibitors against the disease with satisfactory therapeutic outcomes.

Discovery and Anti-Inflammatory Activity of a Cyanobacterial Fatty Acid Targeting the Keap1/Nrf2 Pathway

The monounsaturated fatty acid 7(E)-9-keto-hexadec-7-enoic acid (1) and three structurally related analogues with different oxidation states and degrees of unsaturation (2-4) were discovered from a marine benthic cyanobacterial mat collected from Delta Shoal, Florida Keys. Their structures were elucidated using NMR spectroscopy and mass spectrometry. The structure of 1 contained an α,β-unsaturated carbonyl system, a key motif required for the activation of the Keap1/Nrf2-ARE pathway that is involved in the activation of antioxidant and phase II detoxification enzymes. Compounds 1-4 were screened in ARE-luciferase reporter gene assay using stably transfected HEK293 cells, and only 1 significantly induced Nrf2 activity at 32 and 10 µM, whereas 2-4 were inactive. As there is crosstalk between inflammation and oxidative stress, subsequent biological studies were focused on 1 to investigate its anti-inflammatory potential. Compound 1 induced Nqo1, a well-known target gene of Nrf2, and suppressed iNos transcript levels, which translated into reduced levels of nitric oxide in LPS-activated mouse macrophage RAW264.7 cells, a more relevant model for inflammation. RNA sequencing was performed to capture the effects of 1 on a global level and identified additional canonical pathways and upstream regulators involved in inflammation and immune response, particularly those related to multiple sclerosis. A targeted survey of marine cyanobacterial samples from other geographic locations, including Guam, suggested the widespread occurrence of 1. Furthermore, the previous isolation of 1 from marine diatoms and green algae implied a potentially important ecological role across marine algal eukaryotes and prokaryotes. The previous isolation from sea lettuce raises the possibility of dietary intervention to attenuate inflammation and related disease progression.

Ameliorative effects of Fingolimod (FTY720) on microglial activation and psychosis-related behavior in short term cuprizone exposed mice

Schizophrenia is a psychiatric disorder that affects around 1% of the population in widespread populations, with severe cases leading to long-term hospitalization and necessitation of lifelong treatment. Recent studies on schizophrenia have highlighted the involvement of inflammatory and immunoregulatory mechanisms with the onset of symptoms, and the usage of anti-inflammatory treatments are being tested against periods of rapid psychosis. In the central nervous system, microglia are the innate immune population which are activated in response to a wide range of physical and psychological stress factors and produce proinflammatory mediators such as cytokines. Microglial activation and neuroinflammation has been associated to numerous psychiatric disorders including schizophrenia, especially during psychotic episodes. Thus, novel treatments which dampen microglial activation may be of great relevance in the treatment of psychiatric disorders. Fingolimod (FTY720) is a drug used as an immunosuppressive treatment to multiple sclerosis. Recent clinical trials have focused on FTY720 as a treatment for the behavioral symptoms in schizophrenia. However, the mechanisms of Fingolimod in treating the symptoms of schizophrenia are not clear. In this study we use a recently developed neuroinflammatory psychosis model in mice: cuprizone short-term exposure, to investigate the effects of FTY720 administration. FTY720 administration was able to completely alleviate methamphetamine hypersensitivity caused by cuprizone exposure. Moreover, administration of FTY720 improved multiple measures of neuroinflammation (microglial activation, cytokine production, and leucocyte infiltration). In conclusion, our results highlight the future use of FTY720 as a direct anti-inflammatory treatment against microglial activation and psychosis.

Molecular and neuroimmune pharmacology of S1P receptor modulators and other disease-modifying therapies for multiple sclerosis

Multiple sclerosis (MS) is a neurological, immune-mediated demyelinating disease that affects people in the prime of life. Environmental, infectious, and genetic factors have been implicated in its etiology, although a definitive cause has yet to be determined. Nevertheless, multiple disease-modifying therapies (DMTs: including interferons, glatiramer acetate, fumarates, cladribine, teriflunomide, fingolimod, siponimod, ozanimod, ponesimod, and monoclonal antibodies targeting ITGA4, CD20, and CD52) have been developed and approved for the treatment of MS. All the DMTs approved to date target immunomodulation as their mechanism of action (MOA); however, the direct effects of some DMTs on the central nervous system (CNS), particularly sphingosine 1-phosphate (S1P) receptor (S1PR) modulators, implicate a parallel MOA that may also reduce neurodegenerative sequelae. This review summarizes the currently approved DMTs for the treatment of MS and provides details and recent advances in the molecular pharmacology, immunopharmacology, and neuropharmacology of S1PR modulators, with a special focus on the CNS-oriented, astrocyte-centric MOA of fingolimod.

Repurposing drugs against Alzheimer's disease: can the anti-multiple sclerosis drug fingolimod (FTY720) effectively tackle inflammation processes in AD?

Therapeutic approaches providing effective medication for Alzheimer's disease (AD) patients after disease onset are urgently needed. Previous studies in AD mouse models and in humans suggested that physical exercise or changed lifestyle can delay AD-related synaptic and memory dysfunctions when treatment started in juvenile animals or in elderly humans before onset of disease symptoms. However, a pharmacological treatment that can reverse memory deficits in AD patients was thus far not identified. Importantly, AD disease-related dysfunctions have increasingly been associated with neuro-inflammatory mechanisms and searching for anti-inflammatory medication to treat AD seems promising. Like for other diseases, repurposing of FDA-approved drugs for treatment of AD is an ideally suited strategy to reduce the time to bring such medication into clinical practice. Of note, the sphingosine-1-phosphate analogue fingolimod (FTY720) was FDA-approved in 2010 for treatment of multiple sclerosis patients. It binds to the five different isoforms of Sphingosine-1-phosphate receptors (S1PRs) that are widely distributed across human organs. Interestingly, recent studies in five different mouse models of AD suggest that FTY720 treatment, even when starting after onset of AD symptoms, can reverse synaptic deficits and memory dysfunction in these AD mouse models. Furthermore, a very recent multi-omics study identified mutations in the sphingosine/ceramide pathway as a risk factor for sporadic AD, suggesting S1PRs as promising drug target in AD patients. Therefore, progressing with FDA-approved S1PR modulators into human clinical trials might pave the way for these potential disease modifying anti-AD drugs.

Plant-based production of an orally active cyclotide for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a debilitating disease that requires prolonged treatment with often severe side effects. One experimental MS therapeutic currently under development is a single amino acid mutant of a plant peptide termed kalata B1, of the cyclotide family. Like all cyclotides, the therapeutic candidate [T20K]kB1 is highly stable as it contains a cyclic backbone that is cross-linked by three disulfide bonds in a knot-like structure. This stability is much sought after for peptide drugs, which despite exquisite selectivity for their targets, are prone to rapid degradation in human serum. In preliminary investigations, it was found that [T20K]kB1 retains oral activity in experimental autoimmune encephalomyelitis, a model of MS in mice, thus opening up opportunities for oral dosing of the peptide. Although [T20K]kB1 can be synthetically produced, a recombinant production system provides advantages, specifically for reduced scale-up costs and reductions in chemical waste. In this study, we demonstrate the capacity of the Australian native Nicotiana benthamiana plant to produce a structurally identical [T20K]kB1 to that of the synthetic peptide. By optimizing the co-expressed cyclizing enzyme, precursor peptide arrangements, and transgene regulatory regions, we demonstrate a [T20K]kB1 yield in crude peptide extracts of ~ 0.3 mg/g dry mass) in whole plants and close to 1.0 mg/g dry mass in isolated infiltrated leaves. With large-scale plant production facilities coming on-line across the world, the sustainable and cost-effective production of cyclotide-based therapeutics is now within reach.

Genetics and epigenetics of rare hypersomnia

Herein we focus on connections between genetics and some central disorders of hypersomnolence - narcolepsy types 1 and 2 (NT1, NT2), idiopathic hypersomnia (IH), and Kleine-Levin syndrome (KLS) - for a better understanding of their etiopathogenetic mechanisms and a better diagnostic and therapeutic definition. Gene pleiotropism influences neurological and sleep disorders such as hypersomnia; therefore, genetics allows us to uncover common pathways to different pathologies, with potential new therapeutic perspectives. An important body of evidence has accumulated on NT1 and IH, allowing a better understanding of etiopathogenesis, disease biomarkers, and possible new therapeutic approaches. Further studies are needed in the field of epigenetics, which has a potential role in the modulation of biological specific hypersomnia pathways.

Fingolimod effects on the brain are mediated through biochemical modulation of bioenergetics, autophagy, and neuroinflammatory networks

Fingolimod (FTY720) is an oral drug approved by the Food and Drug Administration (FDA) for management of multiple sclerosis (MS) symptoms, which has also shown beneficial effects against Alzheimer's (AD) and Parkinson's (PD) diseases pathologies. Although an extensive effort has been made to identify mechanisms underpinning its therapeutic effects, much remains unknown. Here, we investigated Fingolimod induced proteome changes in the cerebellum (CB) and frontal cortex (FC) regions of the brain which are known to be severely affected in MS, using a tandem mass tag (TMT) isobaric labeling-based quantitative mass-spectrometric approach to investigate the mechanism of action of Fingolimod. This study identified 6749 and 6319 proteins in CB and FC, respectively, and returned 2609 and 3086 differentially expressed proteins in mouse CB and FC, respectively, between Fingolimod treated and control groups. Subsequent bioinformatics analyses indicated a metabolic reprogramming in both brain regions of the Fingolimod treated group, where oxidative phosphorylation was upregulated while glycolysis and pentose phosphate pathway were downregulated. In addition, modulation of neuroinflammation in the Fingolimod treated group was indicated by upregulation of retrograde endocannabinoid signaling and autophagy pathways, and downregulation of neuroinflammation related pathways including neutrophil degranulation and the IL-12 mediated signaling pathway. Our findings suggest that Fingolimod may exert its protective effects on the brain by inducing metabolic reprogramming and neuroinflammation pathway modulation.

Forskolin, an Adenylcyclase/cAMP/CREB Signaling Activator Restoring Myelin-Associated Oligodendrocyte Destruction in Experimental Ethidium Bromide Model of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neurodegenerative disease marked by oligodendrocyte loss, which results in central neuronal demyelination. AC/cAMP/CREB signaling dysregulation is involved in the progression of MS, including mitochondrial dysfunctions, reduction in nerve growth factors, neuronal inflammation, apoptosis, and white matter degeneration. Our previous research has shown that Forskolin (FSK), a naturally occurring direct adenylyl cyclase (AC)/cAMP/CREB activator, has neuroprotective potential to alleviate pathogenic factors linked with numerous neurological abnormalities. The current study intends to explore the neuroprotective potential of FSK at doses of 40 mg/kg and 60 mg/kg alone, as well as in combination with conventional medicines, such as Fingolimod (FNG), Donepezil (DON), Memantine (MEM), and Simvastatin (SIM) in EB-induced demyelinated experimental MS rats. Adult Wistar rats were divided into nine groups, and EB was infused stereotaxically in the rat brain’s intracerebropeduncle (ICP) area. Chronic gliotoxin EB treatment results in demyelination as well as motor and cognitive dysfunctions. FSK, combined with standard medications, improves behavioral dysfunctions, such as neuromuscular and motor deficits and memory and cognitive abnormalities. Following pharmacological treatments improved remyelination by enhancing myelin basic protein and increasing AC, cAMP, and CREB levels in brain homogenates. Furthermore, FSK therapy restored brain mitochondrial-ETC complex enzymes and neurotransmitter levels while decreasing inflammatory cytokines and oxidative stress markers. The Luxol fast blue (LFB) stain results further indicate FSK’s neuroprotective potential in preventing oligodendrocyte death. Therefore, the results of these studies contribute to a better understanding of the possible role that natural phytochemicals FSK could have in preventing motor neuron diseases, such as multiple sclerosis.

Sphingolipid metabolism and signaling in cardiovascular diseases

Sphingolipids are a structural component of the cell membrane, derived from sphingosine, an amino alcohol. Its sphingoid base undergoes various types of enzymatic transformations that lead to the formation of biologically active compounds, which play a crucial role in the essential pathways of cellular signaling, proliferation, maturation, and death. The constantly growing number of experimental and clinical studies emphasizes the pivotal role of sphingolipids in the pathophysiology of cardiovascular diseases, including, in particular, ischemic heart disease, hypertension, heart failure, and stroke. It has also been proven that altering the sphingolipid metabolism has cardioprotective properties in cardiac pathologies, including myocardial infarction. Recent studies suggest that selected sphingolipids may serve as valuable biomarkers useful in the prognosis of cardiovascular disorders in clinical practice. This review aims to provide an overview of the current knowledge of sphingolipid metabolism and signaling in cardiovascular diseases.

The Role of Sphingomyelin and Ceramide in Motor Neuron Diseases

Amyotrophic Lateral Sclerosis (ALS), Spinal Bulbar Muscular Atrophy (SBMA), and Spinal Muscular Atrophy (SMA) are motor neuron diseases (MNDs) characterised by progressive motor neuron degeneration, weakness and muscular atrophy. Lipid dysregulation is well recognised in each of these conditions and occurs prior to neurodegeneration. Several lipid markers have been shown to predict prognosis in ALS. Sphingolipids are complex lipids enriched in the central nervous system and are integral to key cellular functions including membrane stability and signalling pathways, as well as being mediators of neuroinflammation and neurodegeneration. This review highlights the metabolism of sphingomyelin (SM), the most abundant sphingolipid, and of its metabolite ceramide, and its role in the pathophysiology of neurodegeneration, focusing on MNDs. We also review published lipidomic studies in MNDs. In the 13 studies of patients with ALS, 12 demonstrated upregulation of multiple SM species and 6 demonstrated upregulation of ceramides. SM species also correlated with markers of clinical progression in five of six studies. These data highlight the potential use of SM and ceramide as biomarkers in ALS. Finally, we review potential therapeutic strategies for targeting sphingolipid metabolism in neurodegeneration.