The expression and meaning of HE4 in chronic obstructive pulmonary disease

Abstract

Objective To study the expression level of human epididymis protein 4 (HE4) in chronic obstructive pulmonary disease (COPD), so as to find a new biological marker for COPD. Methods According to the obtained parameters of forced expiratory volume in the first second/forced vital capacity, 12 patients who received surgical treatment for lung diseases were included and divided into the control group (6 cases) and the COPD group (6 cases). The distribution and expression of HE4 in human lung tissues were detected by immunohistochemistry.In the animal model, 24 male C57BL/6 mice at 6 weeks were randomly divided into control group and COPD group by random number table method, 12 mice in each group.The COPD group was exposed to ozone at 3 ppm twice a week for 3 hours each time, and the control group was exposed to air under the same conditions.1 week and 3 weeks later, 6 mice were killed 24 hours after the last exposure in each group.Enzyme-linked immunosorbent assay was used to detect HE4 expression in bronchoalveolar lavage fluid in mice.In cell experiments, human bronchial epithelial cells were pretreated with 1%, 2.5%, and 5% concentrations of cigarette smoke extract for 24 hours, and the expression level of HE4 mRNA was detected by real-time quantitative reverse transcript-polymerase chain reaction. Results There was less HE4 expression in bronchial epithelial cells of COPD group than the control group (t=2.267, P<0.05). After 1 and 3 weeks, the HE4 expression levels in bronchoalveolar lavage fluid of ozone model mice were less than the control group (t=2.423, 2.987, both P<0.05). After pretreatment with 2.5%, 5% cigarette smoke extract, the expression levels of HE4 mRNA in human bronchial epithelial cells were less than the control group (t=3.895, 4.060, both P<0.05). Conclusions The decreased expression level of HE4 in COPD bronchial epithelial cells indicates that HE4 may be involved in the occurrence and development of COPD and it may be a potential biomarker of COPD. Key words: Pulmonary disease, chronic obstructive; Human epididymis protein 4