The expressions and meanings of BMP-7 and TGF-β in idiopathic pulmonary fibrosis and idiopathic nonspecific interstitial pneumonia

Abstract

To investigate the expressions of cytokines in idiopathic pulmonary fibrosis (IPF) and in idiopathic nonspecific interstitial pneumonia (INSIP); To discuss expressions and meanings of bone morphogenetic protein 7 (BMP-7) and transforming growth factor beta (TGF-β) in IPF and IPF. Selected 47 cases of idiopathic interstitial pneumonia (IIP), which were diagnosed by clinical-radiologic-pathologic (CRP), and classified into two groups which were group IPF (25 IPF) and group INSIP (22 INSIP, including 6 cellular pattern and 16 fibrosing pattern). The normal lung tissues were collected as the control group: The fresh tissues were made to detect more than 114 kinds of cytokines' expressions via Oligo GEArray gene microarray technology. Made a tissue microarray which applied EnVision immunohistochemistry technology to detect the expressions of BMP-7 and TGF-β in both kinds of IIPs. The two groups of patients were followed-up visited around 5 to 8 years and the survival curves were evaluated by Kaplan-Meier method. According to gene microarray results, these two groups were up-expression in TGF family,IL family and TNF family. Most of BMP members were down-expression, in comparison with the control group, except BMP-5,BMP-8B and BMP-15. As the tissue microarray results demonstrated, compared with normal lung tissues,BMP-7 expressed decreasingly in IPF and INSIP groups (t1 = 27.618, P < 0.001; t2 = -12.404, P < 0.001). The expression of IPF were lower than INSIP (t = 5.387, P < 0.05); In INSIP group, patients of cellular pattern expressed BMP-7 more than fibrosing pattern's (t = -5.341, P < 0.001). There were dramatically increasing expressions of TGF-β in IPF and INSIP, when compared with the control group (t1 = 23.393, P < 0.001; t2 = -13.445, P < 0.001) and it presented negative correlation with BMP-7(group IPF: r = -0.771, P < 0.001; group INSIP: r = -0.729, P < 0.001). (3) Clinical follow-up data showed, the stability(improvement), deterioration and death rates of the group IPF and the group INSIP were, respectively, 0(0%), 2 (8%), 23 (92%) and 15 (68.1%), 3 (13.6%), 4 (18.2%). The results were statistically significant (all P < 0.05). The median survival time of the part with higher BMP-7 expression and the part with relatively lower BMP-7 expression, in the group IPF, were 110.8 and 66.4 months (t = -2.686, P < 0.05); In the group INSIP, were 146.4 and 74.9 months (t = -3.037, P < 0.05). Cellular cytokines presented different expression profiles in IPF and INSIP patients. Differently with highly activated TGF-β, BMP-7 was inhibited in IIP patients, which would remind the degree of fibrosis and prognosis of IIP. BMP-7 would be expected to be a novel target for IIP pathogenesis and prognostic research.