Expression profiling of laser-microdissected intrapulmonary arteries in hypoxia-induced pulmonary hypertension

Kwapiszewska Grazyna, Wilhelm Jochen, Wolff Stephanie, Laumanns Isabel, Koenig, Ziegler Andreas, Seeger Werner, Bohle, Weissmann Norbert, Fink, Fink Ludger

Description

Chronic hypoxia influences gene expression in the lung resulting in pulmonary hypertension and vascular remodelling. For specific investigation of the vascular compartment, laser-microdissection of intrapulmonary arteries was combined with array profiling. Methods and Results Analysis was performed on mice subjected to 1, 7 and 21 days of hypoxia (FiO 2 = 0.1) using nylon filters (1176 spots). Changes in the expression of 29, 38, and 42 genes were observed at day 1, 7, and 21, respectively. Genes were grouped into 5 different classes based on their time course of response. Gene regulation obtained by array analysis was confirmed by real-time PCR. Additionally, the expression of the growth mediators PDGF-B, TGF-β, TSP-1, SRF, FGF-2, TIE-2 receptor, and VEGF-R1 were determined by real-time PCR. At day 1, transcription modulators and ion-related proteins were predominantly regulated. However, at day 7 and 21 differential expression of matrix producing and degrading genes was observed, indicating ongoing structural alterations. Among the 21 genes upregulated at day 1, 15 genes were identified carrying potential hypoxia response elements (HREs) for hypoxia-induced transcription factors. Three differentially expressed genes (S100A4, CD36 and FKBP1a) were examined by immunohistochemistry confirming the regulation on protein level. While FKBP1a was restricted to the vessel adventitia, S100A4 and CD36 were localised in the vascular tunica media. Conclusion Laser-microdissection and array profiling has revealed several new genes involved in lung vascular remodelling in response to hypoxia. Immunohistochemistry confirmed regulation of three proteins and specified their localisation in vascular smooth muscle cells and fibroblasts indicating involvement of different cells types in the remodelling process. The approach allows deeper insight into hypoxic regulatory pathways specifically in the vascular compartment of this complex organ.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2005
• Nombre de lectures: 1 757
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Respiratory Research

BioMedCentral

Open Access Research Expression profiling of laser-microdissected intrapulmonary arteries in hypoxia-induced pulmonary hypertension 1 1 1 Grazyna Kwapiszewska, Jochen Wilhelm, Stephanie Wolff, 1 22 3 Isabel Laumanns, Inke R Koenig, Andreas Ziegler, Werner Seeger, 1 31 Rainer M Bohle, Norbert Weissmannand Ludger Fink*

1 2 Address: Departmentof Pathology, JustusLiebigUniversity Giessen, Germany,Department of Medical Biometry and Statistics, University at 3 Luebeck, Germany andDepartment of Internal Medicine, JustusLiebigUniversity Giessen, Germany Email: Grazyna Kwapiszewska  [e-mail]giessen.de; Jochen Wilhelm  [e-mail] giessen.de; Stephanie Wolff  [e-mail]giessen.de; Isabel Laumanns  [e-mail]giessen.de; Inke R Koenig  [e-mail]luebeck.de; Andreas Ziegler  [e-mail]luebeck.de; Werner Seeger  [e-mail]giessen.de; Rainer M Bohle  [e-mail]giessen.de; Norbert Weissmann  [e-mail]giessen.de; Ludger Fink*  [e-mail]giessen.de * Corresponding author

Published: 19 September 2005Received: 05 January 2005 Accepted: 19 September 2005 Respiratory Research2005,6:109 doi:10.1186/1465-9921-6-109 This article is available from: http://respiratory-research.com/content/6/1/109 © 2005 Kwapiszewska et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract Background:Chronic hypoxia influences gene expression in the lung resulting in pulmonary hypertension and vascular remodelling. For specific investigation of the vascular compartment, laser-microdissection of intrapulmonary arteries was combined with array profiling.

Methods and Results:Analysis was performed on mice subjected to 1, 7 and 21 days of hypoxia (FiO =0.1) using nylon filters (1176 spots). Changes in the expression of 29, 38, and 42 genes were 2 observed at day 1, 7, and 21, respectively. Genes were grouped into 5 different classes based on their time course of response. Gene regulation obtained by array analysis was confirmed by real- time PCR. Additionally, the expression of the growth mediators PDGF-B, TGF-β, TSP-1, SRF, FGF- 2, TIE-2 receptor, and VEGF-R1 were determined by real-time PCR. At day 1, transcription modulators and ion-related proteins were predominantly regulated. However, at day 7 and 21 differential expression of matrix producing and degrading genes was observed, indicating ongoing structural alterations. Among the 21 genes upregulated at day 1, 15 genes were identified carrying potential hypoxia response elements (HREs) for hypoxia-induced transcription factors. Three differentially expressed genes (S100A4, CD36 and FKBP1a) were examined by immunohistochemistry confirming the regulation on protein level. While FKBP1a was restricted to the vessel adventitia, S100A4 and CD36 were localised in the vascular tunica media.

Conclusion:Laser-microdissection and array profiling has revealed several new genes involved in lung vascular remodelling in response to hypoxia. Immunohistochemistry confirmed regulation of three proteins and specified their localisation in vascular smooth muscle cells and fibroblasts indicating involvement of different cells types in the remodelling process. The approach allows deeper insight into hypoxic regulatory pathways specifically in the vascular compartment of this complex organ.

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