Objective: To investigate the expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR-2/KDR) in lung tissues of emphysema patients.
Methods: The peripheral lung tissues were obtained from 35 patients undergoing pneumonectomy. They were divided into three groups: emphysema group (n = 16), control group (n = 14) and smoking group (n = 5). The level of VEGF protein in lung homogenates was measured by ELISA. The expression of KDR protein in lung was determined by immunohistochemistry, the expression of VEGF and KDR mRNA was detected by reverse transcription polymerase chain reaction, and the apoptosis in lung tissues was observed by terminal transferase dUTP nick end labeling (TUNEL).
Results: The level of VEGF protein of emphysema group [(2.77 +/- 1.0) pg/ml] was significantly decreased when compared with control group [(4.51 +/- 1.68) pg/ml, P < 0.01]. The expression of KDR protein, VEGF mRNA and KDR mRNA of emphysema group were lower than those of control group (P < 0.01). The number of TUNEL+ cells in the alveolar septa was significantly increased in the emphysema lungs when compared with the control (P < 0.01). There was no significant difference between smoking group and control group in the expression of VEGF and KDR (P > 0.05).
Conclusion: The decrease of VEGF and KDR and the increase of alveolar septal cell apoptosis may contribute to the pathogenesis of emphysema.