Increased regulatory activity of intestinal innate lymphoid cells type 3 (ILC3) prevents experimental autoimmune encephalomyelitis severity.

Experimental autoimmune encephalomyelitis (EAE) induced in inbred rodents, i.e., genetically identical animals kept under identical environmental conditions, shows variable clinical outcomes. We investigated such variations of EAE in Dark Agouti rats immunized with spinal cord homogenate and identified four groups: lethal, severe, moderate, and mild, at day 28 post immunization. Higher numbers of CD4+ T cells, helper T cells type 1 (Th1) and 17 (Th17) in particular, were detected in the spinal cord of the severe group in comparison with the moderate group. In addition, increased proportion of Th1 and Th17 cells, and heightened levels of interferon (IFN)-γ and interleukin (IL)-6 were detected in the small intestine lamina propria of the severe group. A selective agonist of free fatty acid receptor type 2 (Ffar2) applied orally in the inductive phase of EAE shifted the distribution of the disease outcomes towards milder forms. This effect was paralleled with potentiation of intestinal innate lymphoid cells type 3 (ILC3) regulatory properties, and diminished Th1 and Th17 cell response in the lymph nodes draining the site of immunization. Our results suggest that different clinical outcomes in DA rats are under determinative influence of intestinal ILC3 activity during the inductive phase of EAE.

Distributions of Platelet-Derived Growth Factor Receptor-α Positive Cells and Interstitial Cells of Cajal in the Colon of Rats with Diabetes Mellitus Type 2.

Background and Objectives: Diabetic gastroenteropathy (DG) is a common complication of diabetes mellitus type 2. Interstitial cells are non-neural cells of mesenchymal origin inserted between nerve elements and smooth muscle cells, necessary for normal function and peristaltic contractions in the gastrointestinal (GI) tract. There are at least two types of interstitial cells within the GI muscle layer-interstitial cells of Cajal (ICC) and interstitial platelet-derived growth factor receptor α-positive cells (IPC). The mechanism of diabetic gastroenteropathy is unclear, and interstitial cells disorders caused by metabolic changes in diabetes mellitus (DM) could explain the symptoms of DG (slow intestinal transit, constipation, fecal incontinence). The aim of this study was to identify PDGFRα and c-kit immunoreactive cells in the colon of rats with streptozotocin-nicotinamide-induced diabetes mellitus type 2, as well as to determine their distribution in relation to smooth muscle cells and enteric nerve structures. Materials and Methods: Male Wistar rats were used, and diabetes type 2 was induced by an intraperitoneal injection of streptozotocin, immediately after intraperitoneal application of nicotinamide. The colon specimens were exposed to PDGFRα and anti-c-kit antibodies to investigate interstitial cells; enteric neurons and smooth muscle cells were immunohistochemically labeled with NF-M and desmin antibodies. Results: Significant loss of the intramuscular ICC, myenteric ICC, and loss of their connection in intramuscular linear arrays and around the ganglion of the myenteric plexus were observed with no changes in nerve fiber distribution in the colon of rats with diabetes mellitus type 2. IPC were rarely present within the colon muscle layer with densely distributed PDGFRα+ cells in the colon mucosa and submucosa of both experimental groups. In summary, a decrease in intramuscular ICC, discontinuities and breakdown of contacts between myenteric ICC without changes in IPC and nerve fibers distribution were observed in the colon of streptozotocin/nicotinamide-induced diabetes type 2 rats.

The Significance of MGMT Promoter Methylation Status in Diffuse Glioma.

A single-institution observational study with 43 newly diagnosed diffuse gliomas defined the isocitrate dehydrogenase 1 and 2 (IDH1/2) gene mutation status and evaluated the prognostic relevance of the methylation status of the epigenetic marker O6-methylguanine-DNA methyltransferase (MGMT). Younger patients (<50 years) with surgically resected glioma and temozolomide (TMZ) adjuvant chemotherapy were associated with better prognosis, consistent with other studies. The methylation status depends on the chosen method and the cut-off value determination. Methylation-specific PCR (MSP) established the methylation status for 36 glioma patients (19 (52.8%) positively methylated and 17 (47.2%) unmethylated) without relevancy for the overall survival (OS) (p = 0.33). On the other side, real-time methylation-specific PCR (qMSP) revealed 23 tumor samples (54%) that were positively methylated without association with OS (p = 0.15). A combined MSP analysis, which included the homogenous cohort of 24 patients (>50 years with surgical resection and IDH1/2-wildtype diffuse glioma), distinguished 10 (41.6%) methylated samples from 14 (58.4%) unmethylated samples. Finally, significant correlation between OS and methylation status was noticed (p ≈ 0.05). The OS of the hypermethylated group was 9.6 ± 1.77 months, whereas the OS of the unmethylated group was 5.43 ± 1.04 months. Our study recognized the MGMT promoter methylation status as a positive prognostic factor within the described homogenous cohort, although further verification in a larger population of diffuse gliomas is required.

Phenethyl Ester of Gallic Acid Ameliorates Experimental Autoimmune Encephalomyelitis.

Gallic acid is a phenolic acid present in various plants, nuts, and fruits. It is well known for its anti-oxidative and anti-inflammatory properties. The phenethyl ester of gallic acid (PEGA) was synthesized with the aim of increasing the bioavailability of gallic acid, and thus its pharmacological potential. Here, the effects of PEGA on encephalitogenic cells were examined, and PEGA was found to modulate the inflammatory activities of T cells and macrophages/microglia. Specifically, PEGA reduced the release of interleukin (IL)-17 and interferon (IFN)-γ from T cells, as well as NO, and IL-6 from macrophages/microglia. Importantly, PEGA ameliorated experimental autoimmune encephalomyelitis, an animal model of chronic inflammatory disease of the central nervous system (CNS)-multiple sclerosis. Thus, PEGA is a potent anti-inflammatory compound with a perspective to be further explored in the context of CNS autoimmunity and other chronic inflammatory disorders.

Central nervous system-infiltrated immune cells induce calcium increase in astrocytes via astroglial purinergic signaling.

Interaction between autoreactive immune cells and astroglia is an important part of the pathologic processes that fuel neurodegeneration in multiple sclerosis. In this inflammatory disease, immune cells enter into the central nervous system (CNS) and they spread through CNS parenchyma, but the impact of these autoreactive immune cells on the activity pattern of astrocytes has not been defined. By exploiting naïve astrocytes in culture and CNS-infiltrated immune cells (CNS IICs) isolated from rat with experimental autoimmune encephalomyelitis (EAE), here we demonstrate previously unrecognized properties of immune cell-astrocyte interaction. We show that CNS IICs but not the peripheral immune cell application, evokes a rapid and vigorous intracellular Ca2+ increase in astrocytes by promoting glial release of ATP. ATP propagated Ca2+ elevation through glial purinergic P2X7 receptor activation by the hemichannel-dependent nucleotide release mechanism. Astrocyte Ca2+ increase is specifically triggered by the autoreactive CD4+ T-cell application and these two cell types exhibit close spatial interaction in EAE. Therefore, Ca2+ signals may mediate a rapid astroglial response to the autoreactive immune cells in their local environment. This property of immune cell-astrocyte interaction may be important to consider in studies interrogating CNS autoimmune disease.

Family and Personality Predictors of Clinical Depression and Anxiety in Emerging Adults: Common, Distinctive, or a Vulnerability Continuum?

There is an ongoing debate on the relationship between depression and anxiety, but data on similarities and differences in their predictor profiles are scarce. The aim of our study was to compare family and personality predictors of these disorders among 220 "emerging adults." As such, two clinical groups with noncomorbid depressive and anxiety disorders, and one healthy control group were assessed by sociodemographic questionnaires, Structured Clinical Interview for DSM-IV Disorders and NEO Personality Inventory, Revised. We found significant overlap in family and personality risk profiles, with increasing effect size for predictors common to anxiety and depression when the categories "no disorder-anxiety disorder-depressive disorder" were considered as existing along a continuum. Among the contributing factors we assessed, family psychiatric history, family structure and conflicts with parents were more significant than personality traits. Our study indicates that emerging adults may be more vulnerable to depression than anxiety in the presence of family and personality risk factors.

The H2S Donor GYY4137 Stimulates Reactive Oxygen Species Generation in BV2 Cells While Suppressing the Secretion of TNF and Nitric Oxide.

GYY4137 is a hydrogen sulfide (H2S) donor that has been shown to act in an anti-inflammatory manner in vitro and in vivo. Microglial cells are among the major players in immunoinflammatory, degenerative, and neoplastic disorders of the central nervous system, including multiple sclerosis, Parkinson's disease, Alzheimer's disease, and glioblastoma multiforme. So far, the effects of GYY4137 on microglial cells have not been thoroughly investigated. In this study, BV2 microglial cells were stimulated with interferon-gamma and lipopolysaccharide and treated with GYY4137. The agent did not influence the viability of BV2 cells in concentrations up to 200 µM. It inhibited tumor necrosis factor but not interleukin-6 production. Expression of CD40 and CD86 were reduced under the influence of the donor. The phagocytic ability of BV2 cells and nitric oxide production were also affected by the agent. Surprisingly, GYY4137 upregulated generation of reactive oxygen species (ROS) by BV2 cells. The effect was mimicked by another H2S donor, Na2S, and it was not reproduced in macrophages. Our results demonstrate that GYY4137 downregulates inflammatory properties of BV2 cells but increases their ability to generate ROS. Further investigation of this unexpected phenomenon is warranted.

Complete Freund's adjuvant as a confounding factor in multiple sclerosis research.

Complete Freund's adjuvant (CFA) is used as a standard adjuvant for the induction of experimental autoimmune encephalomyelitis (EAE), the most commonly used animal model in multiple sclerosis studies. Still, CFA induces glial activation and neuroinflammation on its own and provokes pain. In addition, as CFA contains Mycobacteria, an immune response against bacterial antigens is induced in parallel to the response against central nervous system antigens. Thus, CFA can be considered as a confounding factor in multiple sclerosis-related studies performed on EAE. Here, we discuss the effects of CFA in EAE in detail and present EAE variants induced in experimental animals without the use of CFA. We put forward CFA-free EAE variants as valuable tools for studying multiple sclerosis pathogenesis and therapeutic approaches.

Brain inflammation in experimental autoimmune encephalomyelitis induced in Dark Agouti rats with spinal cord homogenate.

We have recently characterized experimental autoimmune encephalomyelitis (EAE) induced in DA rats with spinal cord homogenate without complete Freund's adjuvant (CFA). The main advantage of this multiple sclerosis model is the lack of CFA-related confounding effects which represent the major obstacles in translating findings from EAE to multiple sclerosis. Here, antigen specificity of the cellular and humoral immune response directed against the central nervous system was explored. The reactivity of T and B cells to myelin basic protein, myelin oligodendrocyte glycoprotein, and ß-synuclein was detected. Having in mind that reactivity against ß-synuclein was previously associated with autoimmunity against the brain, the infiltration of immune cells into different brain compartments, i.e. pons, cerebellum, hippocampus, and cortex was determined. T cell infiltration was observed in all structures examined. This finding stimulated investigation of the effects of immunization on DA rat behavior using the elevated plus maze and the open field test. Rats recovered from EAE displayed increased anxiety-like behavior. These data support CFA-free EAE in DA rats as a useful model for multiple sclerosis research.

Ethyl pyruvate ameliorates acute respiratory distress syndrome in mice.

Acute respiratory distress syndrome (ARDS) became a focus of intensive research due to its death toll during the Covid-19 pandemic. An uncontrolled and excessive inflammatory response mediated by proinflammatory molecules such as high mobility group box protein 1 (HMGB1), IL-6, and TNF mounts as a response to infection. In this study, ethyl pyruvate (EP), a known inhibitor of HMGB1, was tested in the model of murine ARDS induced in C57BL/6 mice by intranasal administration of polyinosinic:polycytidylic acid (poly(I:C)). Intraperitoneal administration of EP ameliorated the ARDS-related histopathological changes in the lungs of poly(I:C)-induced ARDS and decreased numbers of immune cells in the lungs, broncho-alveolar lavage fluid and draining lymph nodes (DLN). Specifically, fewer CD8+ T cells and less activated CD4+ T cells were observed in DLN. Consequently, the lungs of EP-treated animals had fewer damage-inflicting CD8+ cells and macrophages. Additionally, the expression and production of proinflammatory cytokines, IL-17, IFN-γ and IL-6 were downregulated in the lungs. The expression of chemokine CCL5 which recruits immune cells into the lungs was also reduced. Finally, EP downregulated the expression of HMGB1 in the lungs. Our results imply that EP should be further evaluated as a potential candidate for ARDS therapy.

A Comparison of MGMT Testing by MSP and qMSP in Paired Snap-Frozen and Formalin-Fixed Paraffin-Embedded Gliomas.

Comparative analysis of the conventional methylation-specific PCR (MSP) vs. the quantitative MSP (qMSP) assessment of the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in 34 snap-frozen (SF) glioma samples was performed. The accuracy of the semi-quantitative MSP was compared with the corresponding qMSP semi-quantitative values using two semi-quantitative cut-off values (0-unmethylated and 1-weakly methylated) to discriminate methylated from unmethylated samples. In the case of the cut-off value 0, MSP test showed 80.0% sensitivity and 78.9% specificity compared to the reference qMSP analysis. However, when using the cut-off value 1, the diagnostic accuracy of the MSP test was significantly higher (85.7% sensitivity, 85.2% specificity). Fleiss' Kappa statistical analyses indicated moderate agreement (Fleiss' Kappa Coefficient = 0.509; 70.59% agreement) between MSP and qMSP semi-quantitative measurements of MGMT promoter methylation in glioma patients, justifying the conventional MSP use in diagnostics and confirming its high reliability. Further, we aimed to compare the validity of SF and formalin-fixed paraffin-embedded (FFPE) glioma samples for MGMT testing. Statistical analyses indicated moderate overall agreement of FFPE glioma samples and SF MSP semi-quantitative measurements (Fleiss' Kappa Coefficient = 0.516/0.509; 70.0% agreement) and emphasized their low reliability in the assessment of highly methylated MGMT promoter samples.

Phenethyl ester of rosmarinic acid ameliorates experimental autoimmune encephalomyelitis.

Rosmarinic acid is a polyphenolic compound, abundantly present in herbs of the Lamiaceae family. The aim of the study was to evaluate the immunomodulatory properties of a recently developed phenethyl ester derivative of rosmarinic acid (PERA), with enhanced ability of diffusion through biological membranes, in an animal model of the central nervous system (CNS) autoimmunity. To this end, experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis was used. Daily subcutaneous administration of PERA (30 mg/kg) from day 7 to day 22 after immunization successfully ameliorated EAE induced in Dark Agouti rats, shortening the disease duration and reducing maximal, cumulative and mean clinical score. PERA efficiently reduced production of major encephalitogenic cytokines, interferon (IFN)-γ and interleukin (IL)-17, in immune cells from the CNS or the lymph nodes draining the site of immunization of EAE rats, as well as in CD4+ T cells purified from the lymph nodes. Also, PERA inhibited NO production in the CNS and the lymph nodes, as well as in macrophages and microglial cells. Finally, microglial ability to produce pro-inflammatory cytokines IL-6, and tumor necrosis factor (TNF) were also reduced by PERA. Our results clearly imply that PERA possesses anti-encephalitogenic properties. Thus, further studies on the relevance of the observed effects for the therapy of multiple sclerosis are warranted.

Complete Freund's adjuvant-free experimental autoimmune encephalomyelitis in Dark Agouti rats is a valuable tool for multiple sclerosis studies.

Experimental autoimmune encephalomyelitis (EAE) is classically induced with complete Freund's adjuvant (CFA). The immune response against CFA has a confounding influence on the translational capacity of EAE as a multiple sclerosis model. Here, we compare clinical, cellular and molecular properties between syngeneic spinal cord homogenate (SCH)- and SCH + CFA-immunized Dark Agouti rats. EAE signs were observed earlier and the cumulative clinical score was higher without CFA. Also, a higher number of immune cells infiltrates in the spinal cords was noticed at the peak of EAE without CFA. High spinal cord abundance of CD8+CD11bc+MHC class II+ cells was detected in SCH-immunized rats. Myelin basic protein -specific response can be elicited in the cells from the lymph nodes draining the site of SCH immunization. This CFA-free EAE is a reliable multiple sclerosis model.

Upregulation of Tolerogenic Pathways by the Hydrogen Sulfide Donor GYY4137 and Impaired Expression of H2S-Producing Enzymes in Multiple Sclerosis.

The aim of this study was to examine the in vitro effects of the slow-releasing H2S donor GYY4137 on the immune cells involved in the pathogenesis of the central nervous system (CNS) autoimmune disease, multiple sclerosis (MS). GYY4137 specifically potentiated TGF-ß expression and production in dendritic cells and significantly reduced IFN-γ and IL-17 production in the lymph node and spinal cord T cells obtained from mice immunized with CNS antigens. Both the proportion of FoxP3+ regulatory CD4+ T cells in the lymph node cells, and the percentage of IL-17+ CD4+ T cells in the spinal cord cells were reduced upon culturing with GYY4137. Interestingly, the peripheral blood mononuclear cells obtained from the MS patients had a lower expression of the H2S-producing enzyme, 3-mercaptopyruvate-sulfurtransferase (MPST), in comparison to those obtained from healthy donors. A significant inverse correlation between the expression of MPST and several pro-inflammatory factors was also observed. Further studies on the relevance of the observed results for the pathogenesis and therapy of MS are warranted.

Oral neonatal antibiotic treatment perturbs gut microbiota and aggravates central nervous system autoimmunity in Dark Agouti rats.

Gut microbiota dysbiosis has been considered the essential element in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Antibiotics were administered orally to Dark Agouti (DA) rats early in their life with the aim of perturbing gut microbiota and investigating the effects of such intervention on the course of EAE. As a result, the diversity of the gut microbiota was reduced under the influence of antibiotics. Mainly, Firmicutes and Actinobacteria were replaced by Proteobacteria and Bacteroidetes, while decreased proportions of Clostridia and Bacilli classes were accompanied by an increase in Gamma-Proteobacteria in antibiotic-treated animals. Interestingly, a notable decrease in the Helicobacteraceae, Spirochaetaceae and Turicibacteriaceae was scored in antibiotic-treated groups. Also, levels of short chain fatty acids were reduced in the faeces of antibiotic-treated rats. Consequently, aggravation of EAE, paralleled with stronger immune response in lymph nodes draining the site of immunization, and increased inflammation within the CNS, were observed in antibiotic-treated DA rats. Thus, the alteration of gut microbiota leads to an escalation of CNS-directed autoimmunity in DA rats. The results of this study indicate that antibiotic use in early life may have subsequent unfavourable effects on the regulation of the immune system.