Increased Pyruvate Dehydrogenase Kinase 4 Expression in Lung Pericytes Is Associated with Reduced Endothelial-Pericyte Interactions and Small Vessel Loss in Pulmonary Arterial Hypertension

TY - JOUR

T1 - Increased Pyruvate Dehydrogenase Kinase 4 Expression in Lung Pericytes Is Associated with Reduced Endothelial-Pericyte Interactions and Small Vessel Loss in Pulmonary Arterial Hypertension

AU - Yuan, Ke

AU - Shao, Ning-Yi

AU - Hennigs, Jan K

AU - Discipulo, Marielle

AU - Orcholski, Mark E

AU - Shamskhou, Elya

AU - Richter, Alice

AU - Hu, Xinqian

AU - Wu, Joseph C

AU - de Jesus Perez, Vinicio

N1 - Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

PY - 2016/9

Y1 - 2016/9

N2 - Reduced endothelial-pericyte interactions are linked to progressive small vessel loss in pulmonary arterial hypertension (PAH), but the molecular mechanisms underlying this disease remain poorly understood. To identify relevant gene candidates associated with aberrant pericyte behavior, we performed a transcriptome analysis of patient-derived donor control and PAH lung pericytes followed by functional genomics analysis. Compared with donor control cells, PAH pericytes had significant enrichment of genes involved in various metabolic processes, the top hit being PDK4, a gene coding for an enzyme that suppresses mitochondrial activity in favor of glycolysis. Given reports that link reduced mitochondrial activity with increased PAH cell proliferation, we hypothesized that increased PDK4 is associated with PAH pericyte hyperproliferation and reduced endothelial-pericyte interactions. We found that PDK4 gene and protein expression was significantly elevated in PAH pericytes and correlated with reduced mitochondrial metabolism, higher rates of glycolysis, and hyperproliferation. Importantly, reducing PDK4 levels restored mitochondrial metabolism, reduced cell proliferation, and improved endothelial-pericyte interactions. To our knowledge, this is the first study that documents significant differences in gene expression between human donor control and PAH lung pericytes and the link between mitochondrial dysfunction and aberrant endothelial-pericyte interactions in PAH. Comprehensive characterization of these candidate genes could provide novel therapeutic targets to improve endothelial-pericyte interactions and prevent small vessel loss in PAH.

AB - Reduced endothelial-pericyte interactions are linked to progressive small vessel loss in pulmonary arterial hypertension (PAH), but the molecular mechanisms underlying this disease remain poorly understood. To identify relevant gene candidates associated with aberrant pericyte behavior, we performed a transcriptome analysis of patient-derived donor control and PAH lung pericytes followed by functional genomics analysis. Compared with donor control cells, PAH pericytes had significant enrichment of genes involved in various metabolic processes, the top hit being PDK4, a gene coding for an enzyme that suppresses mitochondrial activity in favor of glycolysis. Given reports that link reduced mitochondrial activity with increased PAH cell proliferation, we hypothesized that increased PDK4 is associated with PAH pericyte hyperproliferation and reduced endothelial-pericyte interactions. We found that PDK4 gene and protein expression was significantly elevated in PAH pericytes and correlated with reduced mitochondrial metabolism, higher rates of glycolysis, and hyperproliferation. Importantly, reducing PDK4 levels restored mitochondrial metabolism, reduced cell proliferation, and improved endothelial-pericyte interactions. To our knowledge, this is the first study that documents significant differences in gene expression between human donor control and PAH lung pericytes and the link between mitochondrial dysfunction and aberrant endothelial-pericyte interactions in PAH. Comprehensive characterization of these candidate genes could provide novel therapeutic targets to improve endothelial-pericyte interactions and prevent small vessel loss in PAH.

U2 - 10.1016/j.ajpath.2016.05.016

DO - 10.1016/j.ajpath.2016.05.016

M3 - SCORING: Journal article

C2 - 27456128

VL - 186

SP - 2500

EP - 2514

JO - AM J PATHOL

JF - AM J PATHOL

SN - 0002-9440

IS - 9

ER -