Effect of PPARgamma inhibition on pulmonary endothelial cell gene expression: gene profiling in pulmonary hypertension.
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.
Tian
Jing
J
Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912, USA.
Smith
Anita
A
Nechtman
John
J
Podolsky
Robert
R
Aggarwal
Saurabh
S
Snead
Connie
C
Kumar
Sanjiv
S
Elgaish
Manal
M
Oishi
Peter
P
Göerlach
Agnes
A
Fratz
Sohrab
S
Hess
John
J
Catravas
John D
JD
Verin
Alexander D
AD
Fineman
Jeffrey R
JR
She
Jin-Xiong
JX
Black
Stephen M
SM
D000813:Anilides / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000473:pathology; D015824:Blood-Air Barrier / Q000187:drug effects / Q000378:metabolism; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects / Q000235:genetics; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000235:genetics* / Q000473:pathology; D008168:Lung / Q000473:pathology*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics; D047495:PPAR gamma / Q000037:antagonists & inhibitors*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep; D025801:Ubiquitin / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D016335:Zinc Fingers / Q000235:genetics
C457499:2-chloro-5-nitrobenzanilide; D000813:Anilides; D047495:PPAR gamma; D025801:Ubiquitin; D042461:Vascular Endothelial Growth Factor A