Methylated miRNAs may serve as potential biomarkers and therapeutic targets for hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease influenced by genetics, non-genetic and environmental factors that modulate miRNA expression. Currently, no miRNA data are available for HS. In this study, we profiled DNA methylation patterns of miRNA genes associated with HS susceptibility. OBJECTIVES: Identify miRNA gene methylation profiles associated with HS susceptibility. This study examined the methylation patterns of DNAs from 24 healthy controls and 24 patients with HS using Illumina Infinium MethylationEPIC BeadChip array analysis. Methylation patterns of miRNA genes were analysed using KEGG pathway analysis to explore the inversely correlated pathways regulated by miRNAs. RESULTS: We identified 60 CpG sites representing 65 unique microRNA genes including 54 hypomethylated and 6 hypermethylated CpGs as potentially associated with HS. Some of these CpGs were found to be critical for skin function, such as miR-29, miR-200, miR-205, miR-548 and miR-132. The miR-192 is implicated in non-alcoholic fatty liver disease. The miR-200c gene was identified as a vital determinant in regulating skin repair after injury and may contribute to age-associated alterations in wound repair. miR-132 was significantly upregulated during the inflammation phase of wound repair, enhancing the activity of STAT3 and ERK pathways that promote keratinocyte proliferation. CONCLUSIONS: Epigenetically altered microRNA genes are implicated in wound healing, inflammation, keratinocyte proliferation and wound modulation. This is the first study to analyse methylation profiles of miRNA genes in the HS population, highlighting the unique role that miRNAs might play in diagnosing and treating HS.

Chemical components of shredded paper insulation: a preliminary study.

We conducted an evaluation of shredded paper insulation to identify potentially toxic components. The study was to provide a preliminary characterization of a few samples of insulation currently in use. The following samples were analyzed: previously produced insulation (PPI) containing fire retardants, shredded recycled paper (PPI feedstock), freshly produced insulation (FPI), and insulation which had been installed in a residence (II). Volatile constituents were analyzed by GC-MS from headspace air of samples held at room temperature or heated to 90 degrees C. Extractable constituents were sampled by extracting with methylene chloride, and analyzing by GC-MS. Formaldehyde analysis was done according to EPA Method TO11. Headspace air at room temperature contained no detectable quantities of volatile constituents for any sample measured. In headspace air at 90 degrees C, only PPI contained traces of aliphatic and aromatic hydrocarbons and higher aldehydes, and FPI traces of toluene. Extracts of PPI contained traces of octadecadienoic acid methyl ester and aliphatic and aromatic hydrocarbons and higher aldehydes. Extracts of PPI feedstock contained traces of a substituted cyclohexenecarboxylic acid. FPI contained extractable diethyl phthalate (30-50 micrograms/g). Extracts of II contained traces of methyl palmitate, an octadecenoic acid methyl ester, and a phthalate plasticizer. No formaldehyde was detected. PPI was composed of approximately 98 percent paper fiber and 2 percent pre-gelatinized starch. PPI samples agglomerated together with less than 0.01 percent separating from clumps as fine dust. Boron and sodium were expected and confirmed because they were added to PPI and FPI as fire retardants. Chromium, copper, iron, potassium, magnesium, manganese, phosphorus, and silicon were present at detectable concentrations. Study calculations indicate that an occupant would have to completely consume all the fine particles produced from 3.3 kg of insulation per day to have an intake of boron equivalent to the EPA RfD. No other constituent appeared to be present even close to toxicologically relevant amounts.