Gene signature profiles in lung tisses of wild type mice or Has2 heterozygous deficient mice stimulated with ovalbumin

Background: HAS2 is a member of the gene family encoding hyaluronan synthase 2 (HAS2) which can generate high molecular weight hyaluronan (HMW-HA). Although we previously reported that HAS2 is a novel candidate gene for susceptibility to adult asthma., little is known about whether HAS2 dysfunction affect eosinophilic airway inflammation. Objective: We therefore hypothesized that attenuation of HAS2 will enhance eosinophilic airway inflammation. Methods: C57BL/6 wild type (WT) mice, Has2 heterozygous deficient (Has2+/-) mice were used in eosinophilic airway inflammation model which induced by ovalbumin (OVA). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to detect Has2 and HA binding protein mRNA expression levels. Lung tissue and lavage fluid (BALF) were analyzed for inflammation and various cytokines and chemokines. Airway resistance was measured using forced oscillation technique. gene expression analyses were also performed to elucidate further pathogenesis. Results: The expression levels of Has2 mRNA was significantly decreased in OVA stimulated Has2+/- (Has2+/--OVA) mice. Has2+/--OVA mice also displayed significant reduce of CD44, and TGF-beta1 mRNA expression. BALF eosinophil number, levels of various Th2 cytokines and chemokines in BALF, and airway responsiveness were significantly increased in Has2+/--OVA mice compared with similarly treated WT mice. ILK Signaling and PKA signaling were downregulated significantly more in Has2+/--OVA mice compared with similarly treated WT mice. Conclusions: Has2 dysfunction induce more intense allergic eosinophilic airway inflammation and increase of airway hyper responsiveness with impairment of HAS2-CD44-TGF-beta signaling. Modulating HAS2 signaling might provide novel therapeutic targets for intractable bronchial asthma patients. Overall design: 12 strand-specific RNA libraries for high-throughput sequencing were prepared (3 from the lungs of the wild type mice treated with saline, 3 from the lungs of the Has2+/- mice treated with saline, 3 from the lungs of the wild type mice sensitized and interanasaly stimulated with ovalbumin, and 3 from the lungs of the Has2+/- mice stimulated with ovalbumin using the Illumina Stranded mRNA Sample Preparation Kit with 500ng of total RNA according to manufacturer's instructions.