Interleukin-33 Primes Mast Cells for Activation by IgG Immune Complexes

Mast cells (MCs) are heterogeneous cells whose phenotype is modulated by signals received from the local microenvironment. Recent studies have identified the mesenchymal-derived cytokine IL-33 as a potent direct activator of MCs, as well as regulator of their effector phenotype, and have implicated this activity in the ability of mast cells to contribute to murine experimental arthritis. We explored the hypothesis that IL-33 enables participation of synovial MCs in murine K/BxN arthritis by promoting their activation by IgG immune complexes. Compared to wild-type (WT) control mice, transgenic animals lacking the IL-33 receptor ST2 exhibited impaired MC-dependent immune complex-induced vascular permeability (flare) and attenuated K/BxN arthritis. Whereas participation of MCs in this model is mediated by the activating IgG receptor FcγRIII, we pre-incubated bone marrow-derived MCs with IL-33 and found not only direct induction of cytokine release but also a marked increase in FcγRIII-driven production of critical arthritogenic mediators including IL-1β and CXCL2. This “priming” effect was associated with mRNA accumulation rather than altered expression of Fcγ receptors, could be mimicked by co-culture of WT but not ST2^−/− MCs with synovial fibroblasts, and was blocked by antibodies against IL-33. In turn, WT but not ST2^−/− MCs augmented fibroblast expression of IL-33, forming a positive feedback circuit. Together, these findings confirm a novel role for IL-33 as an amplifier of IgG immune complex-mediated inflammation and identify a potential MC-fibroblast amplification loop dependent on IL-33 and ST2.     

Cellulases of Penicillium verruculosum

Nine major cellulolytic enzymes were isolated from a culture broth of a mutant strain of the fungus Penicillium verruculosum: five endo-1, 4-β-glucanases (EGs) having molecular masses 25, 33, 39, 52, and 70 kDa, and four cellobiohydrolases (CBHs: 50, 55, 60, and 66 kDa). Based on amino acid similarities of short sequenced fragments and peptide mass fingerprinting, the isolated enzymes were preliminary classified into different families of glycoside hydrolases: Cel5A (EG IIa, 39 kDa), Cel5B (EG IIb, 33 kDa), Cel6A (CBH II, two forms: 50 and 60 kDa), Cel7A (CBH I: 55 and 66 kDa), Cel7B (EG I: 52 and 70 kDa). The 25 kDa enzyme was identical to the previously isolated Cel12A (EG III). The family assignment was further confirmed by the studies of the substrate specificity of the purified enzymes. High-molecular-weight forms of the Cel6A, Cel7A, and Cel7B were found to possess a cellulose-binding module (CBM), while the catalytically active low-molecular-weight forms of the enzymes, as well as other cellulases, lacked the CBM. Properties of the isolated enzymes, such as substrate specificity toward different polysaccharides and synthetic glycosides, effect of pH and temperature on the enzyme activity and stability, adsorption on Avicel cellulose and kinetics of its hydrolysis, were investigated.     

Health Risk of PCBs and DDTs in Seafood from Southern Iran

Levels of polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane and its metabolites (DDTs) were measured in 18 species of fish, crab, shrimp, and bivalve samples collected from the northern region of the Persian Gulf in Iran. The levels of ∑PCBs varied from 259.92 ± 31.04 ng/g to 1648.88 ± 176.96 ng/g in lipid weight. CB118 showed the highest concentration. ∑DDT variations ranged from ND to 570.45 ± 806.74 ng/g in lipid weight. Health risk was assessed by estimating both dietary intakes and screening values (SVs). Daily intake levels were much lower than the Food and Agriculture Organization (FAO)/World Health Organization (WHO) standards for PCBs and DDTs. Based on an average bodyweight of 73 kg and consumption rates of 0.055 kg/person. day, the SVs for the carcinogen and non-carcinogen effects of PCB and DDT were calculated. Average concentrations of PCBs and DDTs showed that the levels of PCBs exceeded the established SV for carcinogens. This finding suggests the need to enhance risk management regarding seafood consumption through public advisory.     

Dynamic changes in the copy number of pluripotency and cell proliferation genes in human ESCs and iPSCs during reprogramming and time in culture

Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions. The distribution of these variations differed between hESCs and hiPSCs, characterized by large numbers of duplications found in a few hESC samples and moderate numbers of deletions distributed across many hiPSC samples. For hiPSCs, the reprogramming process was associated with deletions of tumor-suppressor genes, whereas time in culture was associated with duplications of oncogenic genes. We also observed duplications that arose during a differentiation protocol. Our results illustrate the dynamic nature of genomic abnormalities in pluripotent stem cells and the need for frequent genomic monitoring to assure phenotypic stability and clinical safety.     

The molecular basis and genotype–phenotype correlations of congenital adrenal hyperplasia (CAH) in Anatolian population

Molecular Biology Reports - Congenital adrenal hyperplasia (CAH) is an autosomal recessive genetic disorder due to presence of mutations in the genes involved in the metabolism of steroid hormones...     

HIV Testing and Diagnosis Rates in Kiev,Ukraine: April 2013 - March 2014

Objective

Data from Ukraine on risk factors for HIV acquisition are limited. We describe the characteristics of individuals testing for HIV in the main testing centres of the Ukrainian capital Kiev, including HIV risk factors, testing rates, and positivity rates.

Methods

As part of a larger study to estimate HIV incidence within Kiev City, we included questions on possible risk factors for HIV acquisition and testing history to existing systems in 4 infectious disease clinics. Data were provided by the person requesting an HIV test using a handheld electronic tablet. All persons (≥16yrs) presenting for an HIV test April 2013–March 2014 were included. Rates per 100,000 were calculated using region-specific denominators for Kiev.

Results

During the study period 6370 individuals tested for HIV, equivalent to a testing rate of 293.2 per 100,000. Of these, 467 (7.8%) were HIV-positive, with the highest proportion positive among 31–35 year olds (11.2%), males (9.4%), people who inject drugs (PWID) (17.9%) and men who have sex with men (MSM) (24.1%). Using published population size estimates of MSM, diagnosis rates for MSM ranged from 490.6to 1548.3/100,000. A higher proportion of heterosexual women compared to heterosexual men reported contact with PWID, (16% vs. 4.7%) suggesting a bridging in risk between PWID and their sexual partners.

Conclusion

Collection of HIV risk factor information in Kiev, essential for the purposes of developing effective HIV prevention and response tools, is feasible. The high percentage of MSM among those testing positive for HIV, may indicate a significant level of undisclosed sex between men in national figures.     

Allele-specific binding of ZFP57 in the epigenetic regulation of imprinted and non-imprinted monoallelic expression

BackgroundSelective maintenance of genomic epigenetic imprints during pre-implantation development is required for parental origin-specific expression of imprinted genes. The Kruppel-like zinc finger protein ZFP57 acts as a factor necessary for maintaining the DNA methylation memory at multiple imprinting control regions in early mouse embryos and embryonic stem (ES) cells. Maternal-zygotic deletion of ZFP57 in mice presents a highly penetrant phenotype with no animals surviving to birth. Additionally, several cases of human transient neonatal diabetes are associated with somatic mutations in the ZFP57 coding sequence.ResultsHere, we comprehensively map sequence-specific ZFP57 binding sites in an allele-specific manner using hybrid ES cell lines from reciprocal crosses between C57BL/6J and Cast/EiJ mice, assigning allele specificity to approximately two-thirds of all binding sites. While half of these are biallelic and include endogenous retrovirus (ERV) targets, the rest show monoallelic binding based either on parental origin or on genetic background of the allele. Parental-origin allele-specific binding is methylation-dependent and maps only to imprinting control differentially methylated regions (DMRs) established in the germline. We identify a novel imprinted gene, Fkbp6, which has a critical function in mouse male germ cell development. Genetic background-specific sequence differences also influence ZFP57 binding, as genetic variation that disrupts the consensus binding motif and its methylation is often associated with monoallelic expression of neighboring genes.ConclusionsThe work described here uncovers further roles for ZFP57-mediated regulation of genomic imprinting and identifies a novel mechanism for genetically determined monoallelic gene expression.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0672-7) contains supplementary material, which is available to authorized users.     

An underground burst of diversity – a new look at the phylogeny and taxonomy of the genus Talpa Linnaeus, 1758 (Mammalia: Talpidae) as revealed by nuclear and mitochondrial genes

Using both nuclear and mitochondrial sequences, we demonstrate high genetic differentiation in the genus Talpa and confirm the existence of cryptic species in the Caucasus and Anatolia, namely, T. talyschensis Vereschagin, 1945, T. ognevi Stroganov, 1948, and Talpa ex gr. levantis. Our data support four clades in the genus Talpa that showed strong geographical associations. The ‘europaea’ group includes six species from the western portion of the genus' range (T. europaea, T. occidentalis, T. romana, T. caeca, T. stankovici, and T. levantis s.l.); another three groups are distributed further east: the ‘caucasica’ group (Caucasus), the ‘davidiana’ group (eastern Anatolia and Elburz) and T. altaica (Siberia). The phylogenetic position of T. davidiana was highlighted for the first time. The order of basal branching remains controversial, which can be attributed to rapid diversification events. The molecular time estimates based on nuclear concatenation estimated the basal divergence of the crown Talpa during the latest Miocene. A putative scenario of Talpa radiation and issues of species delimitation are discussed. © 2015 The Linnean Society of London