Effects of glucocorticoid on Eotaxin,CCR3 and interleukin-5 in experimental asthmatic geinea pig models

Abstract

Objective To observe the percentage of eosinophil(EOS) in peripheral blood,bone marrow and lung tissue and the expressions of Eotaxin,CCR3 and IL-5 in lung tissue in geinea pig asthmatic models and the effects of glucocortieoid, to explore the roles of regulating EOS in signal transmission between lung tissue and bone marrow in guinea pig asthmatics models and to explore the mechanisms of glucocorticoid interventions for asthma. Methods Forty guinea pigs were randomly divided into control group(group A), asthma group(group B), dexamathasone intervention group (group C), budesonide intervention group (group D) (10 in each group). The asthmatic models were established by ovalbumin(OVA) sensitizing and challenging. The animals were sacrificed six hours after the final OVA ehalhnging. Slides were prepared from the specimens of peripheral blood, bone marrow and lung tissue respectively. The specimens of peripheral blood and bone marrow on slides were stained with Wright. Then the total number and percentage of EOS were counted. The specimens of lung tissue on slides were stained with HE. Then the total number of the percentage of eosinophil were counted. The lung tissue slides were stained immunochemically with anti-Eotaxin polyclonal antibody,anti-CCR3 polyclonal antibody and anti-IL-5 polyclonal antibody respectively.The immunoactive ceils were counted and represented as percentages in total cells. The protein expression of Eotaxin in the lung tissue was assayed by Western blot. Results The percentage of EOS in peripheral blood,bone marrow and lung tissue in each group was as follows:group A was (1.33±0.52)%, (1.17±0.41) %,(1.67±0.5)%. Group B was (4.83±0.98)%, (3.17±0.75)%, (4.00±0.89)%. Group C was (2.68±1.03)%,(1.67±0.82)%,(2.83±0.75)%.Group D was (2.67±0.52)%,(1.83±0.75)%,(2.67±0.52)%. Group B was significantly higher than group A,C,D ( P<0.05),and group A was significantly lower than group C, D ( P<0.05), there was not significant difference between group C and group D, but the percentage of EOS in bone marrow seemly decreased more in group C than in group D. The percentages of immunoactive cells of Eotaxin,CCR3 and IL-5 in lung tissue in each group were as follows: group A was (2.29±0.35)%, (2.07±0.15) %, (1.92±0. 09)%. Group B was (3.27±0.42) %, (3.66±0.47)%, (3.03±0.33)%. Group C was (2.80±0.22)%, (2.98±0.45)%, (2.54±0.32)%. Group D was (2.75±0.31) %,(2.65±0.25 ) %, ( 2.32±0.12) %. Group B was significantly higher than group A, C, D ( P <0.05 ), and group A was significantly lower than group C, D (P<0.05), but there was not significant difference between group C and group D. There was positive correlation between the expression of Eotaxin,CCR3 and IL-5 and the percentages of EOS in lung tissue ( r=0.852, P<0.001), ( r=0.671, P<0.001), ( r=0.663, P<0.001). Conclusions The percentage of EOS in peripheral blood, bone marrow and lung tissue increases and supplies a cooperation between the expression of Eotaxin, CCR3 and IL-5 in lung tissue of guinea pig asthmatic models. Glucocorticoids are demonstrated anti-inflammatory effects by inhibiting the expressions and activities of Eotaxin,CCR3 and IL-5 and suppressed EOS inflammation by down-regulated them. Key words: Asthma; Eotaxin; CCR3; Interleukin-5