[A study on expressions of nerve growth factor and its receptor tyrosine kinase receptor A in lung bronchiolar epithelial cells of chronic obstructive pulmonary disease patients].

OBJECTIVE

To study the expressions of nerve growth factor (NGF) and tyrosine kinase receptor A (TrkA) in bronchiolar epithelial cells of patients with chronic obstructive pulmonary disease (COPD).

METHODS

Thirty-one patients admitted to Tongji Hospital from January to June in 2008 for incision of lung tissues were included in the study They were divided into 3 groups: (1) the control group: 9 patients (2 females and 7 males), average age (52 ± 10) years old, who did not smoke and did not have COPD; (2) the COPD group: 11 patients, all male, average age (61 ± 11) years old, who smoked and had a diagnosis of COPD; (3) the smoker group, 11 patients, all male, average age (56 ± 6) years old, who smoked but did not have COPD. The pathological changes were detected by HE staining. The localizations and the levels of NGF and TrkA expressions in bronchiolar epithelial cells were observed by immunohistochemical technology on bronchiolar biopsy sections. The analysis of variance (ANOVA), the student-Newman-Keuls (SNK) and the Pearson correlation coefficient were used for statistical analysis through SPSS13.0.

RESULTS

The COPD group exhibited significantly enhanced NGF and TrkA expression levels, and the positive cell numbers were (41 ± 11)/mm and (45 ± 4)/mm in bronchiolar epithelial cells respectively, as compared with the other 2 groups [(28 ± 9)/mm, (20 ± 3)/mm and (24 ± 6)/mm, (17 ± 6)/mm], q = 4.83 - 7.24, all P < 0.05. A significant positive correlation was found between the expressions of NGF and TrkA in bronchiolar epithelial cells (r = 0.655, all P < 0.05). A significant negative correlation was found between NGF and TrkA expressions and the levels of FEV(1)/FVC (r = -0.486, -0.665, all P < 0.05).

CONCLUSIONS

The expressions of both NGF and TrkA in bronchiolar epithelial cells were significantly increased in COPD patients. It suggested that NGF and TrkA might play an important role in the progress of COPD.