Identification of novel target genes in human lung tissue involved in chronic obstructive pulmonary disease

Abstract

Introduction

As part of a study aimed at illuminating at least some of the complex molecular events taking place in COPD, we screened tissues by means of transcriptome analyses.

Materials and methods

Tissues were subjected to transcriptome analysis. Candidate genes were identified and validated by immunohistochemistry. Primary human lung cells were subjected to stimulation with cigarette smoke extract for further validation by real time PCR.

Results

Six candidate genes were selected for further investigations: Aquaporin 3 (AQP3), extracellular matrix protein 1 (ECM1), four and a half LIM domain 1 (FHL1), milk fat globule epidermal growth factor 8 (MFGE8, lactadherin), phosphodiesterase 4D-interacting protein (PDE4DIP), and creatine transporter SLC6A8. All six proteins were allocated to distinct cell types by immunohistochemistry. Upon stimulation with cigarette smoke extract, human type II pneumocytes showed a dose-dependent down-regulation of MFGE8, while ECM1 and FHL1 also tended to be down-regulated. Although present, none of the candidates was regulated by cigarette smoke extract in primary human macrophages.

Discussion

MFGE8 turned out to be an interesting new candidate gene in COPD deserving further studies.

Keywords:

• COPD
• transcriptome
• MFGE8
• CSE
• cigarette smoke extract
• ETS2

Acknowledgments

The study was funded by the German Center for Lung Research (DZL), disease area COPD, Gen.2. Patient tissues were provided by the BioMaterialBank North, which is funded in part by the Airway Research Center North (ARCN), a member of the German Center for Lung Research (DZL), and is a member of popgen 2.0 network (P2N), which is supported by a grant from the German Ministry for Education and Research (01EY1103). The authors thank Bettina Baron-Lühr, Patricia Prilla, Stefanie Fox, Jasmin Tiebach, Kristin Wiczkowski, and Maria Lammers for their excellent technical assistance as well as Dr Klaas F. Franzen for providing the CSE.

Disclosure

The author Lena Heinbockel is supported by the Deutsche Forschungsgemeinschaft (DFG, project DR797/3-1 611672). The authors report no other conflicts of interest in this work.