Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common autoinflammatory disease in children and is often grouped together with hereditary periodic fever syndromes, although its cause and hereditary nature remain unexplained. We investigated whether differential DNA methylation was present in DNA from peripheral blood mononuclear cells (PBMC) in patients with PFAPA vs. healthy controls. A whole-epigenome analysis (MeDIP and MBD) was performed using pooled DNA libraries enriched for methylated genomic regions and identified candidate genes, two of which were further evaluated with methylation-specific restriction enzymes coupled with qPCR (MSRE-qPCR). The analysis showed that the PIK3AP1 and SPON2 gene regions are differentially methylated in patients with PFAPA. MSRE-qPCR proved to be a quick, reliable, and cost-effective method of confirming results from MeDIP and MBD. Our findings indicate that a B-cell adapter protein (PIK3AP1), as the PI3K binding inhibitor of inflammation, and spondin-2 (SPON2), as a pattern recognition molecule and integrin ligand, could play a role in the etiology of PFAPA. Their role and the impact of changed DNA methylation in PFAPA etiology and autoinflammation need further investigation. Explanation: Our results uncover new insight into autoinflammatory diseases, with emphasis on epigenetic changes that could lead to autoinflammation and be used as a potential markers of disease or as markers of predisposition for the disease. Our research team (leader Tadej Avcin) has proven to be experienced in both genetic and epigenetic analysis. In the laboratory, we set up two new methods of enrichment of methylated DNA in (MeDIP and MBD) and used a new method of using quantitative PCR (MSRE-qPCR) for the analyzed candidate genes with altered DNA methylation.
COBISS.SI-ID: 23920387
Recent research revealed aberrant signal transducer and activator of transcription (STAT) signaling in several autoimmune diseases including SLE. STAT proteins are major components in interferon (IFN)-dependent gene expression and are responsible for signal transduction of over 50 cytokines, hormones and growth factors regulating key cellular processes such as survival, proliferation, and differentiation. This review summarizes the present evidence from experimental animal models and patients with SLE for the involvement of STAT pathways in the pathogenesis of SLE underlining the role of different members of the STAT family. We present also a comprehensive analysis of studies investigating STAT signaling responses in conventional and regulatory subsets of SLE T and B cells and possible implications of STAT inhibition for clinical therapy.
COBISS.SI-ID: 2991532
Activation of the STAT5 signaling pathway up-regulates antiapoptotic protein Bcl2 and drives proliferation of autoreactive conventional CD4 T cells (Tcons). In systemic lupus erythematosus (SLE), an increased T cell Bcl2 content and perturbed homeostasis of CD45RA-FOXP3hi activated regulatory T cells (aTregs) were described. We assessed Tcon/Treg subsets and phosphorylation of STAT5 (pSTAT5) in blood T cells from patients with SLE by using conventional and imaging flow cytometry. Forty-one patients with SLE, 33 healthy controls, and 29 patients with rheumatoid arthritis were included. Long-term monitoring was performed in 39 patients with SLE, which were followed longitudinally for up to 1000 d. Significantly increased Bcl2 protein content in T cells from patients with SLE was associated with IL-7-dependent STAT5 activation, expressed as increased basal levels and nuclear localization of pSTAT5. pSTAT5 levels were significantly increased in the FOXP3 low-expressing CD4+ T cell subsets but not in the aTreg subset, which was significantly decreased in patients with SLE. In contrast to aTreg, SLE Tcon displayed significantly increased pSTAT5 and Bcl2 levels. Moreover, the percentage of Tconexpressing proliferation marker Ki-67 was significantly increased in patients with SLE and was positively correlated with CD4 T cell pSTAT5 levels. Finally, a subgroup of patients characterized by an increased TconpSTAT5/aTreg-pSTAT5 ratio experienced a more aggressive-relapsing disease course and displayed higher time-adjusted cumulative CD4 T cell pSTAT5 levels during follow-up, which were positively correlated with timeadjusted cumulative disease activity. Our results indicate that imbalanced STAT5 phosphorylation, which is related to Bcl2 and Ki-67 expression, may confer survival and proliferative advantage to Tcon over aTreg and could represent a possible marker of SLE disease severity.
COBISS.SI-ID: 6018367
An article on altered homeostasis of regulatory T lymphocytes (Treg) and altered STAT1 / STAT5 signaling in CD4 T lymphocytes in children with systemic lupus erythematosus was published in the renowned rheumatology journal. FOXP3 + Treg, STAT1 / STAT5 phosphorylation in Th cells, and cytokine profiles were measured in the peripheral blood of patients with cSLE (childhood-onset SLE) and in healthy controls using flow cytometry and biochip immunoassay. In patients with cSLE, a significant correlation was found between the expression of the HLA-DR activation marker and a decreased Th number, an increase in the proportion of FOXP3 + Th and a decrease in the proportion of activated Treg (aTreg). The proportion of CD25 cells that may reflect interleukin 2 depletion was significantly increased in the cSLE aTreg but not in the rTreg subtype. Consistent with the results of previous studies, we found increased STAT1 expression in cSLE, along with a significant correlation between decreased Th number and their increased basal STAT phosphorylation. Our results showed that the key difference between pediatric and adult patients with SLE was in Treg homeostasis, namely in the rTreg cell subset. Disturbed aTreg homeostasis, elevated STAT1 protein levels, and STAT5 homeostatic signaling are intrinsic features of the disease itself that are present in both pediatric and adult patients with SLE.
COBISS.SI-ID: 34473177
In one of the leading journals in the field of immunology, we published an article on the role of JAK-STAT signaling pathways in the pathogenesis of systemic lupus erythematosus. In this paper, we presented our original data on the role of STAT5 phosphorylation and STAT1 expression in circulating CD4 + T lymphocytes in patients with SLE associated with a disrupted relationship between conventional T cells and activated regulatory T cells. Our study showed a significant correlation between the level of phosphorylated STAT5 and the long-term clinical course of the disease. The STAT 5 expression ratio in lymphocyte subpopulations was surprisingly stable over time in patients with SLE and was associated with the frequency of new disease onset and correlated with other known indirect indicators for monitoring of the disease severity, indicating intrinsic immunophenotypic character in SLE patients. These findings are particularly interesting because blockers of intracellular receptor signaling are the next group of target drugs. JAK inhibitors - jakinibs (Janus kinase inhibitors JAK1, JAK2, JAK3 and tyrosine kinase 2) and STAT inhibitors (STAT 1 -5) will probably open a new era in the treatment of various autoimmune diseases due to their simple application and strong influence on intracellular signaling pathways also in line with the results of our study.
COBISS.SI-ID: 34139353