The Expression Of Alpha Defensins In Bronchial Asthma And The Regulation Of P2Y2Receptor On Its

Background: Neutrophils are widely recognized in bronchial asthma, whichinvolved in airway inflammation by degranulation and the release of inflammatoryfactors, but the mechanism is still not entirely clear. Αlpha defensins is a class ofcationic antimicrobial peptide mainly present in the neutrophils. The study reportedthat effect on neutrophils surface of P2Y2receptor promoted neutrophildegranulation to participate in inflammation.Objective：To investigate expression of alpha defensins and effection of P2Y2receptor to it in the bronchial asthma．Methods：the experiment was divided into two parts．The part of Animal experiment：Seventy-two healthy adult male guinea pigs wererandomly divided into control group（C）and asthmatic group（A）；Asthmatic modelwas established by OVA sensitive method．saline instead of ovalbumin as a control；then the control group and asthmatic group was divided into saline group（C1/A1）、The intervention group of ATP（C2/A2）、The intervention group of suramin（C3/A3）and are given intraperitoneal injections of saline，the ATP25mg/kg andsuramin7.5mg/kg，we obtained specimens after20hours．To measure total cells andeosinophils，and neutrophil counts in Bronchoalveolar lavage fluid（BALF）；theprotein expression of IL-8、the mRNA expression of P2Y2and the mRNA andprotein expression of alpha defensin（sRNP）were detected in plasma and lung tissueof guinea pig．The part of Cell experiment：We selected neutrophils as a specimen fromattacking of bronchial asthma patients and healthy volunteers； respectivelyintervented and cultured（The P2Y2receptor inducer of ATP and the antagonists ofsuramin）；The protein expression of IL-8、HNP1-3and the mRNA and protein expression of P2Y2were detected in supernatants and neutrophils．Results：The results of animal experiments（1） The number of total cells、eosinophils and neutrophils in BALF from A1Group was significantly higher than C1group（P<0.05）；The count of total cells andneutrophils in BALF from A1group were more than A3group and less than A2group（P <0.05）；It was not significant difference to compare between the group C（P>0.05）．（2）The protein and mRNAexpression of RNP from A1group between that of A2and A3，but was higher than C1group（P<0.05）；the protein and mRNA expressionof RNP from C1group was less than C2group but more than C3group（P<0.05）．（3）The expression of IL-8from A1group between that of A2and A3，but washigher than C1group（P<0.05）；It was not significant difference to comparebetween the group C（P>0.05）．（4）The expression of P2Y2mRNA may be related to their intervention．Theexpression of P2Y2mRNA in lung tissue from C1and A1group between that oftheir intervention group of ATP and suramin（P<0.05）；Its expression from A1Group was significantly higher than C1group too（P<0.05）．（5）There was a positive correlation among the expression of RNP and RL、neutrophils、IL-8in lung tissue and blood from guinea pigs．The results of cell experiment（1）The protein and mRNA expression of HNP1-3of isolated and culturedneutrophils from asthmatic patients were higher than control and compared withATP intervention of asthma group that is reduced，but suramin that is increased inthe intervention group（P <0.05）；The control group also appeared in such results（P <0.05）．（2）The protein and mRNA expression of P2Y2and IL-8from asthmatic groupwas significantly higher than control group（P<0.05）．（3）The mRNA and protein expressions of P2Y2were correlated with inter- ference．The protein and mRNA expression of P2Y2in cultured neutrophils fromasthmatic and control were lower than their ATP intervention group but higher thanthose with suramin intervention group（P<0.05）．Conclusions:1．The expression of alpha defensins increased in bronchial asthma．2. Upregulation of expression of P2Y2receptor induced neutrophildegranulation，it prompted expression of αlpha defensin to participate in airwayinflammation of bronchial asthma．...