Serotonergic drug repurposing in multiple sclerosis: A new possibility for disease-modifying therapy

Antipsychotic medications associated with increased length of hospital stay in autoimmune encephalitis and multiple sclerosis: A retrospective study

BACKGROUND

Antipsychotic medications (APMs) and selective serotonin reuptake inhibitors (SSRIs) are frequently utilized in patients with neuroinflammatory disorders, such as autoimmune encephalitis and multiple sclerosis (MS). This retrospective study investigates how in-hospital treatment with APMs and SSRIs in patients with these neuroinflammatory diseases are associated with differences in hospital length-of-stay (LOS) and mortality.

METHODS

We evaluated all the inpatients in the Stanford University Hospital from 2008 to 2023 diagnosed with either non-infectious encephalitis or MS and subdivided them into those who did or did not receive APMs or SSRIs while hospitalized. We then analyzed whether hospital LOS and mortality differed with these medications.

RESULTS

Among inpatients with non-infectious encephalitis (n = 114), those who were exposed to APMs had a significantly increased mean LOS (11.8 vs 20.9 days, p < 0.01). For inpatients with MS (n = 1095), treatment with an APM was associated with a significant increase in mean LOS (2.8 vs. 7.1, p < 0.00001). When comparing typical to atypical APMs given to subjects with MS, those who received atypical APMs showed a significant increase in LOS (4.3 vs 10.5, p < 0.01), although typical APMs showed significantly increased risk of mortality (p < 0.05). For inpatients with MS and SSRI use, there was a significant increase in mean hospital LOS (3.5 vs 5.3, p < 0.01), with a significant difference found in those who received fluoxetine or citalopram, but not sertraline or escitalopram. Finally, several healthcare disparities were found, including that Black patients were more likely to receive APMs, and those with MS were more likely to receive typical rather than atypical APMs. Conversely, Black patients with MS were less likely to receive SSRI treatment.

CONCLUSIONS

There was a statistically significant increase in LOS associated with APM use in non-infectious encephalitis and MS, as well as with SSRI use in MS. These data reflect the importance of these medications in these neuroinflammatory disorders and suggest that further investigation into their risks and benefits would be warranted.

Gut Bacteria Provide Genetic and Molecular Reporter Systems to Identify Specific Diseases

With genetic information gained from next-generation sequencing (NGS) and genome-wide association studies (GWAS), it is now possible to select for genes that encode reporter molecules that may be used to detect abnormalities such as alcohol-related liver disease (ARLD), cancer, cognitive impairment, multiple sclerosis (MS), diabesity, and ischemic stroke (IS). This, however, requires a thorough understanding of the gut-brain axis (GBA), the effect diets have on the selection of gut microbiota, conditions that influence the expression of microbial genes, and human physiology. Bacterial metabolites such as short-chain fatty acids (SCFAs) play a major role in gut homeostasis, maintain intestinal epithelial cells (IECs), and regulate the immune system, neurological, and endocrine functions. Changes in butyrate levels may serve as an early warning of colon cancer. Other cancer-reporting molecules are colibactin, a genotoxin produced by polyketide synthetase-positive Escherichia coli strains, and spermine oxidase (SMO). Increased butyrate levels are also associated with inflammation and impaired cognition. Dysbiosis may lead to increased production of oxidized low-density lipoproteins (OX-LDLs), known to restrict blood vessels and cause hypertension. Sudden changes in SCFA levels may also serve as a warning of IS. Early signs of ARLD may be detected by an increase in regenerating islet-derived 3 gamma (REG3G), which is associated with changes in the secretion of mucin-2 (Muc2). Pro-inflammatory molecules such as cytokines, interferons, and TNF may serve as early reporters of MS. Other examples of microbial enzymes and metabolites that may be used as reporters in the early detection of life-threatening diseases are reviewed.

The role of biogenic amines in the modulation of monocytes in autoimmune neuroinflammation

Multiple sclerosis (MS) is inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS) with autoimmune mechanism of development. The study of the neuroimmune interactions is one of the most developing directions in the research of the pathogenesis of MS. The influence of biogenic amines on the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and MS was shown by the modulation of subsets of T-helper cells and B-cells, which plays a crucial role in the autoimmunity of the CNS. However, along with T- and B-cells the critical involvement of mononuclear phagocytes such as dendritic cells, macrophages, and monocytes in the development of neuroinflammation also was shown. It was demonstrated that the activation of microglial cells (resident macrophages of the CNS) could initiate the neuroinflammation in the EAE, suggesting their role at an early stage of the disease. In contrast, monocytes, which migrate from the periphery into the CNS through the blood-brain barrier, mediate the effector phase of the disease and cause neurological disability in EAE. In addition, the clinical efficacy of the therapy with depletion of the monocytes in EAE was shown, suggesting their crucial role in the autoimmunity of the CNS. Biogenic amines, such as epinephrine, norepinephrine, dopamine, and serotonin are direct mediators of the neuroimmune interaction and may affect the pathogenesis of EAE and MS by modulating the immune cell activity and cytokine production. The anti-inflammatory effect of targeting the biogenic amines receptors on the pathogenesis of EAE and MS by suppression of Th17- and Th1-cells, which are critical for the CNS autoimmunity, was shown. However, the latest data showed the potential ability of biogenic amines to affect the functions of the mononuclear phagocytes and their involvement in the modulation of neuroinflammation. This article reviews the literature data on the role of monocytes in the pathogenesis of EAE and MS. The data on the effect of targeting of biogenic amine receptors on the function of monocytes are presented.

The Gut-Brain Axis as a Therapeutic Target in Multiple Sclerosis

The CNS is very susceptible to oxidative stress; the gut microbiota plays an important role as a trigger of oxidative damage that promotes mitochondrial dysfunction, neuroinflammation, and neurodegeneration. In the current review, we discuss recent findings on oxidative-stress-related inflammation mediated by the gut-brain axis in multiple sclerosis (MS). Growing evidence suggests targeting gut microbiota can be a promising strategy for MS management. Intricate interaction between multiple factors leads to increased intra- and inter-individual heterogeneity, frequently painting a different picture in vivo from that obtained under controlled conditions. Following an evidence-based approach, all proposed interventions should be validated in clinical trials with cohorts large enough to reach significance. Our review summarizes existing clinical trials focused on identifying suitable interventions, the suitable combinations, and appropriate timings to target microbiota-related oxidative stress. Most studies assessed relapsing-remitting MS (RRMS); only a few studies with very limited cohorts were carried out in other MS stages (e.g., secondary progressive MS-SPMS). Future trials must consider an extended time frame, perhaps starting with the perinatal period and lasting until the young adult period, aiming to capture as many complex intersystem interactions as possible.

[The influence of fluoxetine on neuroimmune interaction in multiple sclerosis]

OBJECTIVE

To study the effect of fluoxetine on Th17- and Th1-immune response, which plays an important role in the pathogenesis of multiple sclerosis (MS).

MATERIAL AND METHODS

Ten patients with relapsing-remitting MS and ten healthy subjects were examined. The functions of Th17- and Th1-immune responses were assessed by the production of cytokines interleukin-17 (IL-17) and interferon-gamma (IFN-γ) by CD4+ T cells stimulated with macrophages or microbeads coated with anti-CD3 and anti-CD28-antibodies. To assess the effect of fluoxetine on the macrophages-induced Th17- and Th1-immune response, macrophages were pre-incubated in the presence of fluoxetine and co-cultured with autologous CD4+ T-cells. In the case of stimulation of CD4+ T-cells with anti-CD3/CD28-microbeads, fluoxetine was added directly to the T-helper cells before adding of microbeads. In addition, we evaluated the effect of fluoxetine on the production of the factors of differentiation of Th17-cells cytokines IL-6 and IL-1β by macrophages. The levels of cytokines in the cell culture supernatants were measured by ELISA.

RESULTS

The production of IL-17 and IFN-γ by CD4+ T-cells stimulated with macrophages or anti-CD3/CD28-microbeads was comparable between the groups. Fluoxetine suppressed the production of IL-17 and IFN-γ by anti-CD/CD28-stimulated CD4+ T-cells in both groups. Fluoxetine also suppressed the production of IL-6 and IL-1β by macrophages as well as their ability to induce IL-17 and IFN-γ production by CD4+ T-cells in both groups.

CONCLUSIONS

Fluoxetine may have an anti-inflammatory effect in MS that could be mediated by suppression of Th17- and Th1-cells or macrophage-induced Th17- and Th1-immune response.

Th17-cells in depression: Implication in multiple sclerosis

Depression is one of the most common neuropsychological symptoms of multiple sclerosis. However, in addition to mood disorder, depression can also influence on multiple sclerosis course. The mechanism of this dependence is not fully understood. The recent studies suggest the possible common immune mechanisms in the pathogenesis of depression and multiple sclerosis. In particular, it was shown that along with biogenic amines disturbance, neuroinflammation also play an important role in the pathogenesis of depression. Significant attention is drawn to Th17-cells subsets, which are considered as critical players in the pathogenesis of inflammatory diseases of the central nervous system, including multiple sclerosis. This brief report reviews the literature data on the role of neuroinflammation in the reciprocal influence of multiple sclerosis and depression with focus on Th17-cells, which may underlie pathogenetic mechanisms of both this diseases.