1. Effect of PPARgamma inhibition on pulmonary endothelial cell gene expression: gene profiling in pulmonary hypertension.
- Author
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Tian J, Smith A, Nechtman J, Podolsky R, Aggarwal S, Snead C, Kumar S, Elgaish M, Oishi P, Göerlach A, Fratz S, Hess J, Catravas JD, Verin AD, Fineman JR, She JX, and Black SM
- Subjects
- Animals, Arteries drug effects, Arteries pathology, Blood-Air Barrier drug effects, Blood-Air Barrier metabolism, Cattle, Cell Adhesion drug effects, Cell Adhesion genetics, Cell Cycle drug effects, Cell Cycle genetics, Cell Proliferation drug effects, Disease Models, Animal, Endothelial Cells drug effects, Endothelial Cells pathology, Humans, Hypertension, Pulmonary pathology, Neovascularization, Physiologic drug effects, Neovascularization, Physiologic genetics, Reproducibility of Results, Reverse Transcriptase Polymerase Chain Reaction, Sheep, Ubiquitin genetics, Vascular Endothelial Growth Factor A pharmacology, Zinc Fingers genetics, Anilides pharmacology, Endothelial Cells metabolism, Gene Expression Profiling, Gene Expression Regulation drug effects, Hypertension, Pulmonary genetics, Lung pathology, PPAR gamma antagonists & inhibitors
- Abstract
Peroxisome proliferator-activated receptor type gamma (PPARgamma) is a subgroup of the PPAR transcription factor family. Recent studies indicate that loss of PPARgamma is associated with the development of pulmonary hypertension (PH). We hypothesized that the endothelial dysfunction associated with PPARgamma inhibition may play an important role in the disease process by altering cellular gene expression and signaling cascades. We utilized microarray analysis to determine if PPARgamma inhibition induced changes in gene expression in pulmonary arterial endothelial cells (PAEC). We identified 100 genes and expressed sequence tags (ESTs) that were upregulated by >1.5-fold and 21 genes and ESTs that were downregulated by >1.3-fold (P < 0.05) by PPARgamma inhibition. The upregulated genes can be broadly classified into four functional groups: cell cycle, angiogenesis, ubiquitin system, and zinc finger proteins. The genes with the highest fold change in expression: hyaluronan-mediated motility receptor (HMMR), VEGF receptor 2 (Flk-1), endothelial PAS domain protein 1 (EPAS1), basic fibroblast growth factor (FGF-2), and caveolin-1 in PAEC were validated by real time RT-PCR. We further validated the upregulation of HMMR, Flk-1, FGF2, and caveolin-1 by Western blot analysis. In keeping with the microarray results, PPARgamma inhibition led to re-entry of cell cycle at G(1)/S phase and cyclin C upregulation. PPARgamma inhibition also exacerbated VEGF-induced endothelial barrier disruption. Finally we confirmed the downregulation of PPARgamma and the upregulation of HMMR, Flk-1, FGF2, and Cav-1 proteins in the peripheral lung tissues of an ovine model of PH. In conclusion, we have identified an array of endothelial genes modulated by attenuated PPARgamma signaling that may play important roles in the development of PH.
- Published
- 2009
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