BACKGROUND: Great progress has been made in the understanding of inflammatory processes in psoriasis. However, clarifying the role of genetic variability in processes regulating inflammation, including post-transcriptional regulation by microRNA (miRNA), remains a challenge. OBJECTIVES: We therefore investigated single nucleotide polymorphisms (SNPs) with a predicted change in the miRNA/mRNA interaction of genes involved in the psoriasis inflammatory processes. METHODS: Studied SNPs rs2910164 C/G-miR-146a, rs4597342 T/C-ITGAM, rs1368439 G/T-IL12B, rs1468488 C/T-IL17RA were selected using a bioinformatics analysis of psoriasis inflammation-associated genes. These SNPs were then genotyped using a large cohort of women with psoriasis (n = 241) and healthy controls (n = 516). RESULTS: No significant association with psoriasis was observed for rs2910164, rs1368439, and rs1468488 genotypes. However, the major allele T of rs4597342 -ITGAM was associated with approximately 28% higher risk for psoriasis in comparison to the patients with the C allele (OR = 1.28, 95% CI 1.01-1.61, p = 0.037). In case of genotypes, the effect of the T allele indicates the dominant model of disease penetrance as the CT and TT genotypes increase the chance of psoriasis up to 42% in comparison to CC homozygotes of rs4597342 (OR = 1.42, 95% CI = 1.05-1.94, p = 0.025). CONCLUSION: SNP rs4597342 in 3'UTR of ITGAM influencing miR-21 binding may be considered a risk factor for psoriasis development. Upregulated miR-21 in psoriasis is likely to inhibit CD11b production in the case of the rs4597342 T allele which may lead to Mac-1 dysfunction, resulting in an aberrant function of innate immune cells and leading to the production of cytokines involved in psoriasis pathogenesis.
- MeSH
- 3' nepřekládaná oblast genetika MeSH
- alely MeSH
- antigeny CD11b genetika MeSH
- Asijci MeSH
- genetická predispozice k nemoci MeSH
- genetické asociační studie MeSH
- genotyp MeSH
- jednonukleotidový polymorfismus genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- mikro RNA genetika MeSH
- psoriáza genetika patologie MeSH
- rizikové faktory MeSH
- vazebná místa genetika MeSH
- zánět genetika patologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Adenylate cyclase toxin-hemolysin (CyaA, ACT or AC-Hly) of the whooping cough agent Bordetella pertussis penetrates phagocytes expressing the integrin complement receptor 3 (CR3, CD11b/CD18, α(M)β(2) or Mac-1). CyaA translocates its adenylate cyclase (AC) enzyme domain into cell cytosol and catalyzes unregulated conversion of ATP to cAMP, thereby subverting cellular signaling. In parallel, CyaA forms small cation-selective membrane pores that permeabilize cells for potassium efflux, contributing to cytotoxicity of CyaA and eventually provoking colloid-osmotic cell lysis. To investigate whether the single-pass α-helical transmembrane segments of CR3 subunits CD11b and CD18 do directly participate in AC domain translocation and/or pore formation by the toxin, we expressed in CHO cells variants of CR3 that contained artificial transmembrane segments, or lacked the transmembrane segment(s) at all. The results demonstrate that the transmembrane segments of CR3 are not directly involved in the cytotoxic activities of CyaA but serve for maintaining CR3 in a conformation that is required for efficient toxin binding and action.
- MeSH
- adenosintrifosfát chemie MeSH
- adenylátcyklasový toxin metabolismus MeSH
- AMP cyklický biosyntéza MeSH
- antigeny CD11b genetika metabolismus MeSH
- antigeny CD18 genetika metabolismus MeSH
- biologický transport fyziologie MeSH
- Bordetella pertussis metabolismus MeSH
- buněčné linie MeSH
- CHO buňky MeSH
- Cricetulus MeSH
- fagocyty metabolismus MeSH
- lidé MeSH
- makrofágový antigen 1 biosyntéza genetika metabolismus MeSH
- signální transdukce fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We performed a genome-wide association study (GWAS) of IgA nephropathy (IgAN), the most common form of glomerulonephritis, with discovery and follow-up in 20,612 individuals of European and East Asian ancestry. We identified six new genome-wide significant associations, four in ITGAM-ITGAX, VAV3 and CARD9 and two new independent signals at HLA-DQB1 and DEFA. We replicated the nine previously reported signals, including known SNPs in the HLA-DQB1 and DEFA loci. The cumulative burden of risk alleles is strongly associated with age at disease onset. Most loci are either directly associated with risk of inflammatory bowel disease (IBD) or maintenance of the intestinal epithelial barrier and response to mucosal pathogens. The geospatial distribution of risk alleles is highly suggestive of multi-locus adaptation, and genetic risk correlates strongly with variation in local pathogens, particularly helminth diversity, suggesting a possible role for host-intestinal pathogen interactions in shaping the genetic landscape of IgAN.
- MeSH
- antigeny CD11b genetika MeSH
- celogenomová asociační studie MeSH
- genetická pleiotropie genetika MeSH
- genetické lokusy genetika MeSH
- HLA-D antigeny genetika MeSH
- IgA nefropatie genetika MeSH
- imunita genetika MeSH
- interakce hostitele a patogenu genetika MeSH
- jednonukleotidový polymorfismus genetika MeSH
- lidé MeSH
- protoonkogenní proteiny c-vav genetika MeSH
- signální adaptorové proteiny CARD genetika MeSH
- střeva imunologie parazitologie MeSH
- věk při počátku nemoci MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
The aim of this study was to compare two methods for quantification of changes in intracellular potassium concentration (decrease from ∼140 to ∼20mM) due to the action of a pore-forming toxin, the adenylate cyclase toxin (CyaA) from the pathogenic bacterium Bordetella pertussis. CyaA was incubated with stably transfected K1 Chinese hamster ovary cells expressing the toxin receptor CD11b/CD18 and the decrease in potassium concentration in the cells was followed by inductively coupled plasma mass spectrometry (ICP-MS). It is shown that this method is superior in terms of sensitivity, accuracy, and temporal resolution over the method employing the potassium-binding benzofuran isophthalate-acetoxymethyl ester fluorescent indicator. The ICP-MS procedure was found to be a reliable and straightforward analytical approach enabling kinetic studies of CyaA action at physiologically relevant toxin concentrations (<1000ng/ml) in biological microsamples.
- MeSH
- adenylátcyklasový toxin toxicita MeSH
- antigeny CD11b genetika MeSH
- antigeny CD18 genetika MeSH
- Bordetella pertussis enzymologie MeSH
- CHO buňky MeSH
- Cricetulus MeSH
- draslík chemie metabolismus MeSH
- fluorescenční barviva chemie MeSH
- hmotnostní spektrometrie metody MeSH
- intracelulární prostor účinky léků metabolismus MeSH
- křečci praví MeSH
- lidé MeSH
- transfekce MeSH
- zvířata MeSH
- Check Tag
- křečci praví MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- antigeny CD11b genetika MeSH
- celogenomová asociační studie * MeSH
- chronické selhání ledvin MeSH
- genetická pleiotropie genetika MeSH
- genetické lokusy genetika MeSH
- HLA-D antigeny genetika MeSH
- IgA nefropatie * genetika MeSH
- imunita genetika MeSH
- interakce hostitele a patogenu genetika MeSH
- jednonukleotidový polymorfismus genetika MeSH
- lidé MeSH
- protoonkogenní proteiny c-vav genetika MeSH
- signální adaptorové proteiny CARD genetika MeSH
- střeva imunologie MeSH
- věk při počátku nemoci MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- komentáře MeSH
One of the promising approaches in the therapy of ulcerative colitis is administration of butyrate, an energy source for colonocytes, into the lumen of the colon. This study investigates the effect of butyrate producing bacterium Clostridium tyrobutyricum on dextran sodium sulphate (DSS)-induced colitis in mice. Immunocompetent BALB/c and immunodeficient severe combined immunodeficiency (SCID) mice reared in specific-pathogen-free (SPF) conditions were treated intrarectally with C. tyrobutyricum 1 week prior to the induction of DSS colitis and during oral DSS treatment. Administration of DSS without C. tyrobutyricum treatment led to an appearance of clinical symptoms - bleeding, rectal prolapses and colitis-induced increase in the antigen CD11b, a marker of infiltrating inflammatory cells in the lamina propria. The severity of colitis was similar in BALB/c and SCID mice as judged by the histological damage score and colon shortening after 7 days of DSS treatment. Both strains of mice also showed a similar reduction in tight junction (TJ) protein zonula occludens (ZO)-1 expression and of MUC-2 mucin depression. Highly elevated levels of cytokine tumour necrosis factor (TNF)-α in the colon of SCID mice and of interleukin (IL)-18 in BALB/c mice were observed. Intrarectal administration of C. tyrobutyricum prevented appearance of clinical symptoms of DSS-colitis, restored normal MUC-2 production, unaltered expression of TJ protein ZO-1 and decreased levels of TNF-α and IL-18 in the descending colon of SCID and BALB/c mice, respectively. Some of these features can be ascribed to the increased production of butyrate in the lumen of the colon and its role in protection of barrier functions and regulation of IL-18 expression.
- MeSH
- akutní nemoc MeSH
- antigeny CD11b biosyntéza genetika MeSH
- aplikace rektální MeSH
- bakteriální translokace MeSH
- butyráty metabolismus MeSH
- Clostridium tyrobutyricum fyziologie MeSH
- fosfoproteiny biosyntéza genetika MeSH
- imunokompetence MeSH
- interleukin-18 biosyntéza genetika MeSH
- kolon metabolismus mikrobiologie patologie MeSH
- mastné kyseliny metabolismus MeSH
- membránové proteiny biosyntéza genetika MeSH
- mucin 2 biosyntéza genetika MeSH
- muciny biosyntéza MeSH
- myši inbrední BALB C MeSH
- myši SCID MeSH
- myši MeSH
- organismy bez specifických patogenů MeSH
- probiotika terapeutické užití MeSH
- síran dextranu toxicita MeSH
- těžká kombinovaná imunodeficience genetika imunologie MeSH
- TNF-alfa biosyntéza genetika MeSH
- ulcerózní kolitida chemicky indukované genetika imunologie mikrobiologie patologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Adenylate cyclase toxin (CyaA or ACT) is a key virulence factor of pathogenic Bordetellae. It penetrates phagocytes expressing the alpha(M)beta(2) integrin (CD11b/CD18, Mac-1 or CR3) and paralyzes their bactericidal capacities by uncontrolled conversion of ATP into a key signaling molecule, cAMP. Using pull-down activity assays and transfections with mutant Rho family GTPases, we show that cAMP signaling of CyaA causes transient and selective inactivation of RhoA in mouse macrophages in the absence of detectable activation of Rac1, Rac2, or RhoG. This CyaA/cAMP-induced drop of RhoA activity yielded dephosphorylation of the actin filament severing protein cofilin and massive actin cytoskeleton rearrangements, which were paralleled by rapidly manifested macrophage ruffling and a rapid and unexpected loss of macropinocytic fluid phase uptake. As shown in this study for the first time, CyaA/cAMP signaling further caused a rapid and near-complete block of complement-mediated phagocytosis. Induction of unproductive membrane ruffling, hence, represents a novel sophisticated mechanism of down-modulation of bactericidal activities of macrophages and a new paradigm for action of bacterial toxins that hijack host cell signaling by manipulating cellular cAMP levels.
- MeSH
- adenylátcyklasový toxin imunologie metabolismus MeSH
- AMP cyklický imunologie MeSH
- antigeny CD11b genetika imunologie MeSH
- antigeny CD18 genetika imunologie MeSH
- Bordetella pertussis enzymologie imunologie MeSH
- buněčná membrána imunologie metabolismus MeSH
- buněčné linie MeSH
- faktory depolymerizující aktin imunologie metabolismus MeSH
- financování organizované MeSH
- GTP-fosfohydrolasy imunologie metabolismus MeSH
- makrofágový antigen 1 imunologie metabolismus MeSH
- makrofágy imunologie metabolismus MeSH
- mikrofilamenta imunologie metabolismus MeSH
- myši MeSH
- neuropeptidy imunologie metabolismus MeSH
- pertuse enzymologie imunologie MeSH
- rac proteiny vázající GTP imunologie metabolismus MeSH
- rho proteiny vázající GTP imunologie metabolismus MeSH
- signální transdukce imunologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH