Influence of galectin-3 on apoptosis of eosinophils and expression of Bcl-2 protein in lung tissue of asthmatic guinea pigs

Objective:To study the influence of galectin-3 on apoptosis of eosinophils and Bcl-2 protein expression in lung tissue of asthmatic guinea pigs. Methods: Thirty-six guinea pigs were randomly divided into saline group, asthma group and galectin-3 group (n=12). Asthma model was created with ovalbumin (OVA). Galectin-3 (0.5 mg/kg) was injected intraperitoneally daily 1 hour before stimulation during the 15th to 21st day of sensitization in galectin-3 group. Interleukin 5 (IL-5) level and eosinophil counts in bronchoalveolar lavage fluid (BALF) were determined. Pulmonary pathological change was observed. Apoptosis of eosinophils and expression of Bcl-2 protein in lung tissue were detected by TUNEL method and immunohistochemistry, respectively. Results:Compared with asthma group, IL-5 level and eosinophil counts in BALF were significantly lower in galectin-3 group (P0.05). Furthermore, significantly milder inflammatory reaction was observed in lung tissue in galectin-3 group than that in asthma group, with higher eosinophilic apoptosis index and lower expression level of Bcl-2 protein (P0.05). Conclusion:Galectin-3 can reduce the eosinophil counts in BALF and inflammation in lung tissue of asthmatic guinea pigs via reducing IL-5 level in BALF, inhibiting Bcl-2 protein expression and promoting eosinophilic apoptosis.