title: Control of endothelial function and angiogenesis by PGC-1α relies on ROS control of vascular stability.
abstract: Peroxisome proliferator activated receptor g co-activator 1alpha (PGC-1α) is a regulator of oxidative metabolism and reactive oxygen species (ROS) homeostasis that has been show to play a relevant role in angiogenesis. PGC-1α KO mice show reduced vascular density in the retinas and KO primary vascular endothelial cells (ECs) migrate faster than the wild type, an effect that can be rescued by antioxidants, suggesting that excessive ROS levels might be relevant in PGC-1 α role in angiogenesis. This study aims to investigate the role of ROS homeostasis on the regulation by PGC-1 α of angiogenesis. We found that endothelial cells (ECs) from mice deleted for PGC-1 α display attenuated adhesion to the extracellular matrix, together with slower spreading, reduced formation of cellular junctions, a disorganized cytoskeleton and random motility, and a enhanced tip phenotype. Aditionally, PGC-1 α -deleted ECs exhibit an altered response to vascular endothelial growth factor-A (VEGF-A). In vivo, deletion of PGC-1 α results in addition to reduced retinal vascular density, sparse pericyte coverage. Exposure of PGC-1 α deleted mice to hyperoxia during retinal vascular development exacerbates these vascular abnormalities and mice show extensive retinal hemorrhaging, with highly unstructured areas and very poor perfusion, compared with wild-type mice. Structural analysis demonstrates a reduction of endothelial VE-cadherin, suggesting defective inter-cellular junctions. Interestingly, this hyperoxia-induced phenotype is partially reversed by antioxidant administration, indicating that elevated production of mitochondrial reactive oxygen species (ROS) in the absence of PGC-1 α is functionally important. Finally, in vitro studies show that antioxidant treatment improves VEGF-A signaling, suggesting that toxic effect of ROS may be caused by the alteration of the VEGF-A signaling pathway. In summary, our findings indicate that PGC-1 α control of ROS homeostasis plays an important role in the control of de novo angiogenesis, and is required for vascular stability.
authors.affiliation: Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM). Arturo Duperier 4. 28029-Madrid (Spain).
authors.forename: Nieves
authors.initials: N
authors.lastname: García-Quintans
authors.affiliation: Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM). Arturo Duperier 4. 28029-Madrid (Spain).
authors.forename: Cristina
authors.initials: C
authors.lastname: Sánchez-Ramos
authors.affiliation: Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro 3, 28029-Madrid (Spain).
authors.forename: Alberto
authors.initials: A
authors.lastname: Tierrez
authors.affiliation: Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro 3, 28029-Madrid (Spain).
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Olmo
authors.affiliation: Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro 3, 28029-Madrid (Spain).
authors.forename: Alfonso
authors.initials: A
authors.lastname: Luque
authors.affiliation: Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro 3, 28029-Madrid (Spain).
authors.forename: Elvira
authors.initials: E
authors.lastname: Arza
authors.affiliation: Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro 3, 28029-Madrid (Spain).
authors.forename: Arantzazu
authors.initials: A
authors.lastname: Alfranca
authors.affiliation: Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernández Almagro 3, 28029-Madrid (Spain).
authors.forename: Juan
authors.initials: J
authors.lastname: Miguel Redondo
authors.affiliation: Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM). Arturo Duperier 4. 28029-Madrid (Spain).
authors.forename: María
authors.initials: M
authors.lastname: Monsalve
keywords: PGC-1 α; ROS; angiogenesis; vascular endothelium