Effects of combining tumor necrosis factor-α inhibitor with adenosine A2b receptor antagonist on asthmatic lung inflammation in mice

Abstract

Objective To explore the effects of combining tumor necrosis factor-α(TNF-α) inhibitor with adenosine A2b receptor antagonist CVT-6883 on asthmatic lung inflammation in mice. Methods A total of 40 female Balb/c mice were evenly randomized into 5 groups, including normal control group, asthma group, CVT-6883 group, CVT-6883 + etanercept group, and etanercept group.The pathological changes in the lungs were determined and the number of white blood cells(WBC) and eosinophil(EOS) in the bronchoalveolar lavage fluid(BALF) was counted by cell count in each group.The levels of TNF-α in BALF were evaluated by enzyme-linked immunosorbent assay (ELISA). The expression of adenosine A2b receptor mRNA in the lung tissues were measured by reverse transcription-polymerase chain reaction(RT-PCR). Results 1.The lung tissue in asthma group, dyed by HE, was found to have a large number of airway inflammatory cell infiltration, thickening of the bronchial mucosa, the alveolar septa widened and fracture.In the CVT-6883, CVT-6883 + etanercept and etanercept group, the pathological changes were relieved.2.The WBC and EOS counts in BALF of the asthma group[(413.8±5.8)/L, (139.3±1.4)/L] were higher than those of the normal control group[(24.0±1.3)/L, (1.8±0.1)/L, P<0.05]. The WBC and EOS counts of the CVT-6883 group[(111.5±3.8)/L, (3.3±0.1)/L], the etanercept group + the CVT-6883 group[(173.8±3.9)/L, (10.4±0.2)/L], and the etanercept group[(138.4±3.0)/L, (4.1±0.1)/L] were lower than those of the asthma group (P<0.05).3. Compared with the control group(100.4±5.7) ng/L, the TNF-α concentration of the asthma group(145.2±8.8) ng/L was significantly higher (P<0.05); the TNF-α concentration of CVT-6883 group(130.9±5.9) ng/L, CVT-6883 + etanercept group(115.7±8.2) ng/L and the etanercept group(122.0±8.7) ng/L, were significantly decreased compared with asthma group (P<0.05). 4. In asthma group(8.9±1.1)compared with the control group(0.6±0.2), the A2bAR(adenosine A2b receptor) mRNA expression was upregulated (P<0.05); CVT-6883 group(1.6±0.3), CVT-6883 + etanercept group(2.5±0.6)and the etanercept group(5.3±0.4), the A2bAR(adenosine A2b receptor) mRNA expression was significantly decreased compared with asthma group (all P<0.05). Conclusion Combination of TNF-α inhibitor with adenosine A2b receptor antagonist can reduce asthmatic lung inflammation. Key words: Tumor necrosis factor-α; Adenosine A2b receptor; Asthma; Etanercept