BackgroundData from multiple sclerosis (MS) and the MS rodent model, experimental autoimmune encephalomyelitis (EAE), highlighted an inflammation-dependent synaptopathy at the basis of the neurodegenerative damage causing irreversible disability in these disorders. This synaptopathy is characterized by an imbalance between glutamatergic and GABAergic transmission and has been proposed to be a potential therapeutic target.Siponimod (BAF312), a selective sphingosine 1-phosphate1,5 receptor modulator, is currently under investigation in a clinical trial in secondary progressive MS patients. We investigated whether siponimod, in addition to its peripheral immune modulation, may exert direct neuroprotective effects in the central nervous system (CNS) of mice with chronic progressive EAE.MethodsMinipumps allowing continuous intracerebroventricular (icv) infusion of siponimod for 4 weeks were implanted into C57BL/6 mice subjected to MOG35-55-induced EAE. Electrophysiology, immunohistochemistry, western blot, qPCR experiments, and peripheral lymphocyte counts were performed. In addition, the effect of siponimod on activated microglia was assessed in vitro to confirm the direct effect of the drug on CNS-resident immune cells.ResultsSiponimod administration (0.45 μg/day) induced a significant beneficial effect on EAE clinical scores with minimal effect on peripheral lymphocyte counts. Siponimod rescued defective GABAergic transmission in the striatum of EAE, without correcting the EAE-induced alterations of glutamatergic transmission. We observed a significant attenuation of astrogliosis and microgliosis together with reduced lymphocyte infiltration in the striatum of EAE mice treated with siponimod. Interestingly, siponimod reduced the release of IL-6 and RANTES from activated microglial cells in vitro, which might explain the reduced lymphocyte infiltration. Furthermore, the loss of parvalbumin-positive (PV+) GABAergic interneurons typical of EAE brains was rescued by siponimod treatment, providing a plausible explanation of the selective effects of this drug on inhibitory synaptic transmission.ConclusionsAltogether, our results show that siponimod has neuroprotective effects in the CNS of EAE mice, which are likely independent of its peripheral immune effect, suggesting that this drug could be effective in limiting neurodegenerative pathological processes in MS.

Purpose: We evaluated leukemia-associated immunophenotypes (LAIP) and their correlation with fms-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1) gene mutational status in order to contribute a better identification of patients at highest risk of relapse in acute myeloid leukemia (AML).Experimental Design: Bone marrow samples from 132 patients with AML were analyzed by nine-color multiparametric flow cytometry. We confirmed the presence of the mutation in diagnostic samples and in sorted cells by conventional RT-PCR and by patient-specific RQ-PCR.Results: Within the CD34 þ cell fraction, we identified a discrete population expressing high levels of the IL3 receptor a-chain (CD123) and MIC-2 (CD99) in combination with the IL2 receptor a-chain (CD25). The presence of this population positively correlated with the internal tandem duplications (ITD) mutation in the FLT3 gene (r ¼ 0.71). Receiver operating characteristics showed that, within the CD34 þ cell fraction a percentage of CD123/CD99/CD25 þ cells !11.7% predicted FLT3-ITD mutations with a specificity and sensitivity of >90%. CD34/CD123/ CD99/CD25 þ clones were also detectable at presentation in 3 patients with FLT3 wild-type/NPM1 þ AML who relapsed withQuantitative real-time PCR designed at relapse for each FLT3-ITD in these three cases confirmed the presence of low copy numbers of the mutation in diagnostic samples. Conclusions: Our results suggest that the CD34/CD25/ CD123/CD99þ LAIP is strictly associated with FLT3-ITD-positive cells.

Different functional states determine glioblastoma (GBM) heterogeneity. Brain cancer cells coexist with the glial cells in a functional syncytium based on a continuous metabolic rewiring. However, standard glioma therapies do not account for the effects of the glial cells within the tumor microenvironment. This may be a possible reason for the lack of improvements in patients with high-grade gliomas therapies. Cell metabolism and bioenergetic fitness depend on the availability of nutrients and interactions in the microenvironment. It is strictly related to the cell location in the tumor mass, proximity to blood vessels, biochemical gradients, and tumor evolution, underlying the influence of the context and the timeline in anti-tumor therapeutic approaches. Besides the cancer metabolic strategies, here we review the modifications found in the GBM-associated glia, focusing on morphological, molecular, and metabolic features. We propose to analyze the GBM metabolic rewiring processes from a systems biology perspective. We aim at defining the crosstalk between GBM and the glial cells as modules. The complex networking may be expressed by metabolic modules corresponding to the GBM growth and spreading phases. Variation in the oxidative phosphorylation (OXPHOS) rate and regulation appears to be the most important part of the metabolic and functional heterogeneity, correlating with glycolysis and response to hypoxia. Integrated metabolic modules along with molecular and morphological features could allow the identification of key factors for controlling the GBM-stroma metabolism in multi-targeted, time-dependent therapies.

Forkhead box P3 (FoxP3)+ regulatory T cells (Treg) are powerful mediators of immune regulation and immune homeostasis. In humans, Tregs are a heterogeneous population expressing surface markers which define phenotypically and functionally distinct subsets. Moreover, it is now clear that intracellular staining for FoxP3 does not unequivocally identify “true” suppressor cells, since several FoxP3 isoforms exist, and different reagents for FoxP3 detection are available. Here, we propose a strategy to identify potentially functional and suppressive Treg cells in an autoimmune disease like multiple sclerosis, and we suggest that in patients affected by this disease these cells are both reduced in number and functionally exhausted.

Remdesivir was recommended for hospitalized patients with COVID-19. As already reported in the Summary of Product Characteristics, most of remdesivir’s safety concerns are hepatoxicity and nephrotoxicity related. However, some cases have raised concerns regarding the potential cardiac events associated with remdesivir; therefore, the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency requested to investigate all available data. Therefore, we analyzed all Individual Case Safety Reports (ICSRs) collected in the EudraVigilance database focusing on cardiac adverse events. From April to December 2020, 1375 ICSRs related to remdesivir were retrieved from EudraVigilance, of which 863 (62.8%) were related to male and (43.3%) adult patients. A total of 82.2% of all AEs (N = 2604) was serious and one third of the total ICSRs (N = 416, 30.3%) had a fatal outcome. The most frequently reported events referred to hepatic/hepatobiliary disorders (19.4%,), renal and urinary disorders (11.1%) and cardiac events (8.4%). Among 221 cardiac ICSRs, 69 reported fatal outcomes. Other drugs for cardiovascular disorders were reported as suspected/concomitant together with remdesivir in 166 ICSRs (75.1%), 62 of which were fatal. Moreover, the mean time to overall cardiac event was 3.3 days (±2.2). Finally, disproportionality analysis showed a two-fold increased risk of reporting a cardiac adverse event associated with remdesivir compared to both hydroxychloroquine and azithromycin. This study showed that remdesivir could be associated to risk of cardiac events, suggesting a potential safety signal which has not been completely evaluated yet. Further studies are needed to confirm these findings.