Hyphae fragments from A. fumigatus sensitize lung cells to silica particles (Min-U-Sil): Increased release of IL-1ß.

Exposure to particulate matter (PM), such as mineral particles and biological particles/components may be linked to aggravation of respiratory diseases, including asthma. Here we report that exposure to Aspergillus fumigatus hyphae fragments (AFH) and lipopolysaccharide (LPS) induced both mRNA synthesis and release of pro-inflammatory interleukin-1 beta (IL-1ß) in both human THP-1 monocytes (THP-1 Mo) and phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 monocytes (THP-1 macrophages; THP-1 Ma); while Min-U-Sil alone enhanced the release of IL-1ß only in THP-1 Ma. Co-exposure to LPS or AFH with Min-U-Sil caused a synergistic release of IL-1ß when compared to single exposures. In contrast, Min-U-Sil did not markedly change LPS- and AFH-induced release of tumor necrosis factor alpha (TNF-α). The combined exposures did not increase the LPS- and AFH-induced expression of IL-1ß mRNA. Notably, the AFH- and LPS-induced IL-1ß responses with and without co-exposure to Min-U-Sil in THP-1 Mo were found to be caspase-dependent as shown by inhibition with zYVAD-fmk. Furthermore, co-exposure with AFH and Min-U-Sil resulted in similar synergistic releases of IL-1ß in primary human airway macrophages (AM; sputum), peripheral blood monocyte-derived macrophages (MDM) and in the human bronchial epithelial cell line (BEAS-2B). In conclusion, AFH induce both the synthesis and release of IL-1ß. However, Min-U-Sil further enhanced the cleavage of the induced pro-IL-1ß.

Characterization and pro-inflammatory responses of spore and hyphae samples from various mold species.

Mold particles from Aspergillus fumigatus, Penicillium chrysogenum, Aspergillus versicolor, and Stachybotrys chartarum have been linked to respiratory-related diseases. We characterized X-ray-inactivated spores and hyphae fragments from these species by number of particles, morphology, and mycotoxin, ß-glucan and protease content/activity. The pro-inflammatory properties of mold particles were examined in human bronchial epithelial cells (BEAS-2B) and THP-1 monocytes and phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1. Spores from P. chrysogenum and S. chartarum contained some hyphae fragments, whereas the other preparations contained either spores or hyphae. Each mold species produced mainly one gelatin-degrading protease that was either of the metallo- or serine type, while one remains unclassified. Mycotoxin levels were generally low. Detectable levels of ß-glucans were found mainly in hyphae particle preparations. PMA-differentiated THP-1 macrophages were by far the most sensitive model with effects in the order of 10 ng/cm2 . Hyphae preparations of A. fumigatus and P. chrysogenum were more potent than respective spore preparations, whereas the opposite seems to be true for A. versicolor and S. chartarum. Hyphae fragments of A. fumigatus, P. chrysogenum, and A. versicolor enhanced the release of metalloprotease (proMMP-9) most markedly. In conclusion, species, growth stage, and characteristics are all important factors for pro-inflammatory potential.

Differential effects of nitro-PAHs and amino-PAHs on cytokine and chemokine responses in human bronchial epithelial BEAS-2B cells.

Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are found in diesel exhaust and air pollution particles. Along with other PAHs, many nitro-PAHs possess mutagenic and carcinogenic properties, but their effects on pro-inflammatory processes and cell death are less known. In the present study we examined the effects of 1-nitropyrene (1-NP), 3-nitrofluoranthene (3-NF) and 3-nitrobenzanthrone (3-NBA) and their corresponding amino forms, 1-AP, 3-AF and 3-ABA, in human bronchial epithelial BEAS-2B cells. The effects of the different nitro- and amino-PAHs were compared to the well-characterized PAH benzo[a]pyrene (B[a]P). Expression of 17 cytokine and chemokine genes, measured by real-time PCR, showed that 1-NP and 3-NF induced a completely different cytokine/chemokine gene expression pattern to that of their amino analogues. 1-NP/3-NF-induced responses were dominated by maximum effects on CXCL8 (IL-8) and TNF-alpha expression, while 1-AP-/3-AF-induced responses were dominated by CCL5 (RANTES) and CXCL10 (IP-10) expression. 3-NBA and 3-ABA induced only marginal cytokine/chemokine responses. However, 3-NBA exposure induced considerable DNA damage resulting in accumulation of cells in S-phase and a marked increase in apoptosis. B[a]P was the only compound to induce expression of aryl hydrocarbon receptor (AhR)-regulated genes, such as CYP1A1 and CYP1B1, but did not induce cytokine/chemokine responses in BEAS-2B cells. Importantly, nitro-PAHs and amino-PAHs induced both qualitatively and quantitatively different effects on cytokine/chemokine expression, DNA damage, cell cycle alterations and cytotoxicity. The cytokine/chemokine responses appeared to be triggered, at least partly, through mechanisms separate from the other examined endpoints. These results confirm and extend previous studies indicating that certain nitro-PAHs have a considerable pro-inflammatory potential.

In silico analysis of microRNAS targeting the HLA-G 3' untranslated region alleles and haplotypes.

It has been reported that microRNAs (miRNA) may have allele-specific targeting for the 3' untranslated region (3' UTR) of the HLA-G locus. In a previous study, we reported 11 3'UTR haplotypes encompassing the 14-bp insertion/deletion polymorphism and seven SNPs (+3003 T/C, +3010 C/G, +3027 C/A, +3035 C/T, +3142 C/G, +3187 A/G, and +3196 C/G), of which only the +3142 C/G SNP has been reported to influence the binding of miRNAs. Using bioinformatics analyses, we identified putative miRNA-binding sites considering the haplotypes encompassing these eight polymorphic sites, and we ranked the lowest free energies that could potentially lead to an mRNA degradation or translational repression. When a specific haplotype or a particular SNP was associated with a miRNA-binding site, we defined a free energy difference of 4 kcal/mol between alleles to classify them energetically distant. The best results were obtained for the miR-513a-5p, miR-518c*, miR-1262 and miR-92a-1*, miR-92a-2*, miR-661, miR-1224-5p, and miR-433 miRNAs, all influencing one or more of the +3003, +3010, +3027, and +3035 SNPs. The miR-2110, miR-93, miR-508-5p, miR-331-5p, miR-616, miR-513b, and miR-589* miRNAs targeted the 14-bp fragment region, and miR-148a, miR-19a*, miR-152, mir-148b, and miR-218-2 also influenced the +3142 C/G polymorphism. These results suggest that these miRNAs might play a relevant role on the HLA-G expression pattern.