Analysis of the AIRE Gene Promoter in Patients Affected by Autoimmune Polyendocrine Syndromes.

Autoimmune polyglandular syndromes (APS) are classified into four main categories, APS1-APS4. APS1 is caused by AIRE gene loss of function mutations, while the genetic background of the other APS remains to be clarified. Here, we investigated the potential association between AIRE gene promoter Single Nucleotide Polymorphisms (SNPs) and susceptibility to APS. We sequenced the AIRE gene promoter of 74 APS patients, also analyzing their clinical and autoantibody profile, and we further conducted molecular modeling studies on the identified SNPs. Overall, we found 6 SNPs (-230Y, -655R, -261M, -380S, -191M, -402S) of the AIRE promoter in patients' DNA. Interestingly, folding free energy calculations highlighted that all identified SNPs, except for -261M, modify the stability of the nucleic acid structure. A rather similar percentage of APS3 and APS4 patients had polymorphisms in the AIRE promoter. Conversely, there was no association between APS2 and AIRE promoter polymorphisms. Further AIRE promoter SNPs were found in 4 out of 5 patients with APS1 clinical diagnosis that did not harbor AIRE loss of function mutations. We hypothesize that AIRE promoter polymorphisms could contribute to APS predisposition, although this should be validated through genetic screening in larger patient cohorts and in vitro and in vivo functional studies.

Flavonoids as Modulators of Potassium Channels.

Potassium channels are widely distributed integral proteins responsible for the effective and selective transport of K+ ions through the biological membranes. According to the existing structural and mechanistic differences, they are divided into several groups. All of them are considered important molecular drug targets due to their physiological roles, including the regulation of membrane potential or cell signaling. One of the recent trends in molecular pharmacology is the evaluation of the therapeutic potential of natural compounds and their derivatives, which can exhibit high specificity and effectiveness. Among the pharmaceuticals of plant origin, which are potassium channel modulators, flavonoids appear as a powerful group of biologically active substances. It is caused by their well-documented anti-oxidative, anti-inflammatory, anti-mutagenic, anti-carcinogenic, and antidiabetic effects on human health. Here, we focus on presenting the current state of knowledge about the possibilities of modulation of particular types of potassium channels by different flavonoids. Additionally, the biological meaning of the flavonoid-mediated changes in the activity of K+ channels will be outlined. Finally, novel promising directions for further research in this area will be proposed.

Biological effects of bergamot and its potential therapeutic use as an anti-inflammatory, antioxidant, and anticancer agent.

Context: Bergamot, mainly produced in the Ionian coastal areas of Southern Italy (Calabria), has been used since 1700 for its balsamic and medicinal properties. Phytochemical profiling has confirmed that bergamot juices are rich in flavonoids, including flavone and flavanone glycosides which are responsible for its beneficial effects.Objective: Recently, it was shown that the combination of natural compounds with conventional treatments improves the efficacy of anticancer therapies. Natural compounds with anticancer properties attack cancerous cells without being toxic to healthy cells. Bergamot can induce cytotoxic and apoptotic effects and prevent cell proliferation in various cancer cells.Methods: In this review, the antiproliferative, pro-apoptotic, anti-inflammatory, and antioxidant effects of bergamot are described. Information was compiled from databases such as PubMed, Web of Science, and Google Scholar using the key words 'bergamot' accompanied by 'inflammation' and, 'cancer' for data published from 2015-2021.Results: In vitro and in vivo studies provided evidence that different forms of bergamot (extract, juice, essential oil, and polyphenolic fraction) can affect several mechanisms that lead to anti-proliferative and pro-apoptotic effects that decrease cell growth, as well as anti-inflammatory and antioxidant effects.Conclusions: Considering the effects of bergamot and its new formulations, we affirm the importance of its rational use in humans and illustrate how bergamot can be utilized in clinical applications. Numerous studies evaluated the effect of new bergamot formulations that can affect the absorption and, therefore, the final effects by altering the therapeutic profile of bergamot and enhancing the scientific knowledge of bergamot.

Bioassay-Guided Isolation of Antiproliferative Compounds from Limbarda crithmoides (L.) Dumort.

Limbarda crithmoides (L.) Dumort (Asteraceae) n-hexane extract displayed high cell proliferation inhibitory activity against acute myeloid leukaemia cells (OCI-AML3) and was therefore subjected to a bioassay-guided multistep separation procedure. Two thymol derivatives, namely 10-acetoxy-8,9-epoxythymol tiglate (1) and 10-acetoxy-9-chloro-8,9-dehydrothymol (2), were isolated and identified by means of NMR spectroscopy. Both of them exhibited a significant dose-dependent inhibition of cell proliferation.

In Search for the Missing Link in APECED-like Conditions: Analysis of the AIRE Gene in a Series of 48 Patients.

Autoimmune diseases are a heterogeneous group of disorders of the immune system. They can cluster in the same individual, revealing various preferential associations for polyendocrine autoimmune syndromes. Clinical observation, together with advances in genetics and the understanding of pathophysiological processes, has further highlighted that autoimmunity can be associated with immunodeficiency; autoimmunity may even be the first primary immunodeficiency manifestation. Analysis of susceptibility genes for the development of these complex phenotypes is a fundamental issue. In this manuscript, we revised the clinical and immunologic features and the presence of AIRE gene variations in a cohort of 48 patients affected by high polyautoimmunity complexity, i.e., APECED-like conditions, also including patients affected by primary immunodeficiency. Our results evidenced a significant association of the S278R polymorphism of the AIRE gene with APECED-like conditions, including both patients affected by autoimmunity and immunodeficiency and patients with polyautoimmunity compared to healthy controls. A trend of association was also observed with the IVS9+6 G>A polymorphism. The results of this genetic analysis emphasize the need to look for additional genetic determinants playing in concert with AIRE polymorphisms. This will help to improve the diagnostic workup and ensure a precision medicine approach to targeted therapies in APECED-like patients.

Antiviral Activity of Ficus rubiginosa Leaf Extracts against HSV-1, HCoV-229E and PV-1.

Ficus rubiginosa plant extract showed antimicrobial activity, but no evidence concerning its antiviral properties was reported. The antiviral activity of the methanolic extract (MeOH) and its n-hexane (H) and ethyl acetate (EA) fractions against Herpes simplex virus-1 (HSV-1), Human coronavirus (HCoV) -229E, and Poliovirus-1 (PV-1) was investigated in the different phases of viral infection in the VERO CCL-81 cell line. To confirm the antiviral efficacy, a qPCR was conducted. The recorded cytotoxic concentration 50% was 513.1, 298.6, and 56.45 µg/mL for MeOH, H, and EA, respectively, assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay after 72 h of treatment. The Ficus rubiginosa leaf extract inhibited the replication of HSV-1 in the early stages of infection, showing a complete inhibition up to 0.62, 0.31, and 1.25 µg/mL. Against HCoV-229E, a total inhibition up to 1.25 µg/mL for MeOH and H as well as 5 µg/mL for EA was observed. Otherwise, no activity was recorded against PV-1. The leaf extract could act directly on the viral envelope, destructuring the lipid membrane and/or directly blocking the enriched proteins on the viral surface. The verified gene inhibition suggested that the treatments with M, H, and EA impaired HSV-1 and HCoV-229E replication, with a greater antiviral efficiency against HSV-1 compared to HCoV-229E, possibly due to a greater affinity of Ficus rubiginosa towards membrane glycoproteins and/or the different lipid envelopes.

NK cells in autoimmune diseases: Linking innate and adaptive immune responses.

The pathogenesis of autoimmunity remains to be fully elucidated, although the contribution of genetic and environmental factors is generally recognized. Despite autoimmune conditions are principally due to T and B lymphocytes, NK cells also appear to play a role in the promotion and/or maintenance of altered adaptive immune responses or in peripheral tolerance mechanisms. Although NK cells are components of the innate immune system, they shows characteristics of the adaptive immune system, such as the expansion of pathogen-specific cells, the generation of long-lasting "memory" cells able to persist upon cognate antigen encounter, and the possibility to induce an increased secondary recall response to re-challenge. Human NK cells are generally identified as CD56+CD3-, conversely CD56+CD3+ cells represent a mixed population of NK-like T (NK T) cells and antigen-experienced T cells showing the up-regulation of several NK cell markers. CD56dim constitute about 90% of NK cells in the peripheral blood, they are mature and involved in cytotoxicity responses; CD56bright instead are more immature, mostly involved in cytokine production, having only a limited role in cytolytic responses, keen to leave the blood vessels as the principal population observed in lymph nodes. NK cells have been identified also in non-lymphoid tissues since, in pathologic conditions, they can quickly reach the target organs. A cross-talk between NK with dendritic cells and T cells is established throughout different receptor-ligand bindings. Several studies support the correlation between NK cell number and/or functional alterations, such as a defective cytotoxic activity and several autoimmune conditions. Among the different autoimmune pathologies and even within the same disease, NK cell function is significantly different either promoting or even protecting against the onset of the autoimmune condition. In this Review, we discuss recent literature supporting the role played by NK cells, as a bridge between innate and adaptive immunity, in the onset of autoimmune diseases.

Inhibited cell death, NF-kappaB activity and increased IL-10 in TCR-triggered thymocytes of transgenic mice overexpressing the glucocorticoid-induced protein GILZ.

Glucocorticoids promote thymocyte apoptosis and modulate transcription of several genes including GILZ, which is strongly up-regulated in the thymus. We used transgenic mice overexpressing GILZ in the T-cell lineage to investigate TCR-triggered functions of GILZ-overexpressing thymocytes. TCR-triggered apoptosis, but not glucocorticoid-induced apoptosis, was inhibited in transgenic mice compared to their controls. In vivo anti-CD3 administration did not reduce CD4(+)CD8(+) thymocyte number. Analysis of TCR-triggered molecular changes indicated that p65 NF-kappaB nuclear translocation and DNA binding activity was inhibited in transgenic mice, which might be linked with apoptosis inhibition. IL-10 release increased whereas release of IL-2, IFN-gamma, IL-13 and IL-4 remained unchanged. These results support the hypothesis that GILZ regulates, at least in part, T-cell development by influencing thymus function at cellular and molecular levels.

The Use of Mesenchymal Stem Cells for the Treatment of Autoimmunity: From Animals Models to Human Disease.

Mesenchymal stem cells are multipotent progenitors able to differentiate into osteoblasts, chondrocytes and adipocytes. These cells also exhibit remarkable immune regulatory properties, which stimulated both in vitro and in vivo experimental studies to unravel the underlying mechanisms as well as extensive clinical applications. Here, we describe the effects of MSCs on immune cells and their application in animal models as well as in clinical trials of autoimmune diseases. It should be pointed out that, while the number of clinical applications is increasing steadily, results should be interpreted with caution, in order to avoid rising false expectations. Major issues conditioning clinical application are the heterogeneity of MSCs and their unpredictable behavior following therapeutic administration. However, increasing knowledge on the interaction between exogenous cell and host tissue, as well as some encouraging clinical observations suggest that the therapeutic applications of MSCs will be further expanded on firmer grounds in the near future.

Dexamethasone-induced thymocytes apoptosis requires glucocorticoid receptor nuclear translocation but not mitochondrial membrane potential transition.

Dexamethasone (DEX), a glucocorticoid hormone (GCH) with specificity for the glucocorticoid receptor (GR) induces T lymphocyte and thymocyte apoptosis. DEX-activated thymocyte apoptosis requires a sequence of biochemical events including mRNA and protein synthesis. In particular, GCH treatment induces non-genomic mechanisms, such as for example Ca(2+) mobilization and PI-PLC activation, and genomic mechanisms. Most of these events, including protein synthesis, are required and precede caspase activation. As protein synthesis is required for caspases and apoptosis activation, DEX-induced GR nuclear translocation is necessary for apoptosis. Cell treatment with geldanamycin (GA) inhibits the GR nuclear translocation and consequently, caspases activation and apoptosis. Although DEX treatment induces loss of mitochondrial membrane potential (deltapsim) and cytochrome c release, deltapsim induction does not correlate with thymocyte apoptosis. In fact, while Cyclosporin-A and the caspase-9 inhibitor, Z-LEHD-FMK, inhibit DEX-induced deltapsim, do not influence apoptosis. These data indicate many biochemical events and are activated by DEX treatment of thymocytes and some, but not all, are required for apoptosis.

Recent insights on the putative role of autophagy in autoimmune diseases.

The incidence of autoimmune pathologies is increasing worldwide. This has stimulated interest on their etiopathogenesis, caused by a complex interaction of genetic and environmental factors. With the advent of genome-wide linkage, candidate gene and genome wide association studies, risk polymorphisms in autophagy-related genes were discovered in several autoimmune conditions suggesting the possible contribution of autophagy to their etiopathogenesis. Autophagy represents the principal catabolic process mediated by lysosomes used by eukaryotic cells and is strictly regulated by proteins belonging to the Atg family. The function of autophagy has been well characterized in various tissues and systems, but its role in the regulation of innate and adaptive immune systems has been only recently discovered. It plays a fundamental role in the modulation of thymocyte selection and in the generation of T lymphocyte repertoire by participating in the intracellular antigen presentation on MHC class-II molecules by thymic epithelial cells. Furthermore, the generation of mice with knockout for specific autophagy-related genes induced several immunological alterations, including defects in B and T cell compartments and in T cell activation. In this review we report recent evidence on the role of autophagy in autoimmunity and discuss its relevance to the pathogenesis of these diseases. We finally highlight that future research may disclose potential new therapeutic targets for the treatment of this category of disorders by modulating the autophagic pathway.

Recent insights into the role of the PD-1/PD-L1 pathway in immunological tolerance and autoimmunity.

Autoimmune diseases represent a heterogeneous group of conditions whose incidence is increasing worldwide. This has stimulated studies on their etiopathogenesis, derived from a complex interaction between genetic and environmental factors, in order to improve prevention and treatment of these disorders. The relevance of T regulatory cells and of the PD-1/PD-L1 pathway in controlling immune responses has been highlighted. Recent studies have in particular elucidated the putative role of the PD-1/PD-L1 pathway in regulating T cell responses and its effects on immunological tolerance and immune-mediated tissue damage. The role of the PD-1/PD-L1 pathway in autoimmunity has been already investigated in vivo in several experimental animal models including insulin-dependent diabetes mellitus, systemic lupus erythematosus, myocarditis, encephalomyelitis, rheumatoid arthritis and inflammatory bowel diseases. With the advent of candidate gene and genome-wide association studies, single nucleotide polymorphisms (SNPs) in PD-1 gene in humans have demonstrated relevant associations with a higher risk of developing autoimmune diseases in certain ethnic groups. In this review we present recent insights into the role of the PD-1/PD-L1 pathway in regulating lymphocyte activation, promotion of T regulatory cell development and function, breakdown of tolerance and development of autoimmunity. We finally speculate on the possible development of novel therapeutic treatments in human autoimmunity by modulating the PD-1/PD-L1 pathway.

Decrease of Bcl-xL and augmentation of thymocyte apoptosis in GILZ overexpressing transgenic mice.

Glucocorticoids promote thymocyte apoptosis and modulate transcription of numerous genes. GILZ (glucocorticoid-induced leucine zipper), being one of them, is strongly up-regulated in the thymus. To elucidate its function we generated transgenic mice overexpressing it specifically in the T-cell lineage and characterized its influence on thymus function. In young adult transgenic mice CD4(+)CD8(+) thymocyte number was significantly decreased and ex vivo thymocyte apoptosis was increased. Apoptotic pathway analysis detected reduced antiapoptotic B-cell leukemia XL (Bcl-xL) expression and increased activation of caspase-8 and caspase-3. Time-course experiments showed that in wild-type (WT) thymocytes GILZ up-regulation was followed by sequential Bcl-xL decreased expression and activation of caspase-8 and of caspase-3. Moreover, GILZ delivered inside WT thymocytes by a fusion protein with the transactivator of transcription (TAT) peptide decreased Bcl-xL and promoted their apoptosis. In aged mice perturbation of thymic subset numbers was amplified over time, as demonstrated by a further decrease in CD4(+)CD8(+) cells and increases in CD4(+)CD8(-), CD4(-)CD8(-), and CD8(+)CD4(-) cell counts. These results support the hypothesis that GILZ participates in the regulation of thymocyte apoptosis by glucocorticoids.