Association of PSORS1C3, CARD14 and TLR4 genotypes and haplotypes with psoriasis susceptibility.

Psoriasis is a common chronic, immune-mediated inflammatory disease of the skin. PSORS1C3 is a non-protein coding gene, of which the RNA transcript is found in psoriatic patients. CARD14 is mainly expressed in epidermal keratinocytes. TLR4 is a transmembrane protein to recognize microbial antigens. Our study aimed to assess the relationship among PSORS1C3, CARD14 and TLR4 polymorphisms, inflammatory expression and psoriasis susceptibility. To the end, 71 patients with psoriasis and 46 healthy individuals with the well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by Sanger DNA sequencing and secretion of cytokines by ELISA. As a result, genetic analysis of PSORS1C3 gene identified nine SNPs and three haplotype blocks. Sequencing of the CARD14 gene determined eight SNPs and one haplotype block. Sequencing of TLR4 gene identified nine SNPs, in which a SNP rs1018673641 was found to exert deleterious effect. The linkage disequilibrium analysis showed that seven variants in PSORS1C3 gene and three SNPs in CARD14 gene were in tightly linked. More importantly, a significant association between IL-6 level and rs1018673641 AT genotype in TLR4 gene was detected in psoriatic patients. In conclusion, the PSORS1C3, CARD14 and TLR4 polymorphisms and haplotypes may be correlated with risk of suffering psoriasis and the IL-6-mediated chronic inflammation in psoriasis could be partially regulated by the TLR4 functional variant.

Prevalence of CYLD mutations in Vietnamese patients with polycythemia vera.

BACKGROUND: Polycythemia vera (PV) is characterized by increased proliferation and accumulation of erythroid and mature myeloid cells and megakaryocyte in the bone marrow and peripheral blood. The JAK2V617F mutation is present in most PV patients. Deubiquitinase (DUB) genes, including TNFAIP3 (A20), CYLD and Cezanne, function as negative regulators of inflammatory reaction through nuclear factor kappa-light-chain-enhancer of activated B cells (NF-eB) signaling. OBJECTIVES: To determine single nucleotide polymorphisms (SNPs) profiling and gene expression of the DUB genes as well as the immunophenotype of PV cells. MATERIAL AND METHODS: Seventy-seven patients with PV and 55 healthy individuals with well-characterized clinical profiles were enrolled. Gene expression profile was determined using quantitative real-time polymerase chain reaction (qRT-PCR), the immunophenotype with flow cytometry, secretion of cytokines using enzyme-linked immunosorbent assay (ELISA), and gene polymorphisms using direct DNA sequencing. RESULTS: Inactivation of A20, CYLD and Cezanne, and increases in interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-á) levels, as well as the enhanced number of CD25+CD4 T, Th1 and regulatory T cells were observed in PV patients. The genetic analysis of the CYLD gene identified 11 SNPs, in which a novel W736G nsSNP in exon 15 and a SNP c.2483+6 T>G in intron 15 were observed in PV cases with the frequencies of 18.2% and 5.2%, respectively. The W736G non-synonymous SNP (nsSNP) was found to be most likely to exert deleterious effect and the intronic SNP c.2483+6 T>G was identified as aberrant splicing. Sequencing of Cezanne gene identified 7 SNPs in intron 10 and PV carriers of the SNPs had at least 2 SNPs in this gene. Importantly, PV carriers of the W736G nsSNP had multiple SNPs in CYLD, but not in A20 or Cezanne gene. CONCLUSIONS: Two identified SNPs, including the W736G nsSNP and the SNP c.2483+6 T>G, in CYLD gene might be associated with a risk of PV disease, in which the deleterious effect of the W736G nsSNP in CYLD gene could contribute to the pathogenesis of PV.

Regulation of NF-κB- and STAT1-mediated plasmacytoid dendritic cell functions by A20.

Dendritic cells (DCs) are professional antigen presenting cells involved in the induction of T cell-mediated adaptive immunity. Plasmacytoid DCs (pDCs) originate from lymphoid precursors and produce type I interferons (IFNs) in response to pathogens. A20 is considered as a negative regulator of toll-like receptor (TLR) signaling pathways, in which Toxoplasma gondii- derived profilin (TgPRF) is a TLR11/12 ligand recognised by DCs to stimulate their maturation/activation. Little is known about contributions of A20 to changes in biological properties of pDCs. The present study, therefore, explored whether pDC functions are influenced by A20. To this end, bone marrow cells were isolated and cultured with Flt3L to attain CD8DCs, CD11bDCs and pDCs and followed by challenge with TgPRP in the presence or absence of A20 siRNA. Expression of maturation markers were analysed by flow cytometry, and secretion of inflammatory cytokines by ELISA, cell migration by a transwell migration assay and expression of signalling molecules by western blotting. As a result, treatment with A20 siRNA enhanced activations of IκB-α and STAT-1, leading to increases in expressions of maturation markers and cytokine productions as well as migration of TgPRP-treated pDCs, while mature CD11bDCs produced at higher levels of TNF-α and IL-6 only. In addition, functions of CD8DCs remained unaltered following A20 silencing. The effects of A20 on pDC maturation and activation were completely abolished by IKK inhibitor and partially blunted by fludarabine. In conclusion, the inhibitory effects of A20 on pDC functions are expected to affect the immune response in T. gondii infection.