Ana M Figueiredo1, Pilar Villacampa1, Rodrigo Diéguez-Hurtado2, Juan José Lozano3, Piotr Kobialka1, Ana Rosa Cortazar4, Anabel Martinez-Romero5, Ana Angulo-Urarte1, Claudio A Franco6, Marc Claret7, Ana María Aransay8, Ralf H Adams2, Arkaitz Carracedo9, Mariona Graupera5. 1. Vascular Biology and Signalling Group, ProCURE, Oncobell Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Gran Via de l'Hospitalet 199, 08908 L'Hospitalet de Llobregat, Barcelona, Spain. 2. Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, and Faculty of Medicine, University of Münster, Münster, Germany. 3. Bioinformatics Platform, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain. 4. Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain; CIBERONC, Instituto de Salud Carlos III, Av. de Monforte de Lemos, 5, 28029, Madrid, Spain. 5. Vascular Biology and Signalling Group, ProCURE, Oncobell Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Gran Via de l'Hospitalet 199, 08908 L'Hospitalet de Llobregat, Barcelona, Spain; CIBERONC, Instituto de Salud Carlos III, Av. de Monforte de Lemos, 5, 28029, Madrid, Spain. 6. Instituto de Medicina Molecular - João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal. 7. Neuronal Control of Metabolism Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; CIBERDEM, 08036 Barcelona, Spain. 8. Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain; CIBERehd, Instituto de Salud Carlos III, Av. de Monforte de Lemos, 5, 28029, Madrid, Spain. 9. Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain; CIBERONC, Instituto de Salud Carlos III, Av. de Monforte de Lemos, 5, 28029, Madrid, Spain; Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), P. O. Box 644, E-48080 Bilbao, Spain; Ikerbasque.
Abstract
Background: Pericytes regulate vessel stabilization and function and their loss is associated with diseases such as diabetic retinopathy or cancer. Despite their physiological importance, pericyte function and molecular regulation during angiogenesis remain poorly understood. Methods: To decipher the transcriptomic programs of pericytes during angiogenesis, we crossed the Pdgfrb(BAC)-CreERT2 into the RiboTagflox/flox mice. Pericyte morphological changes were assessed in mural cell-specific R26-mTmG reporter mice, in which low doses of tamoxifen allowed labeling of single cell pericytes at high resolution. To study the role of phosphoinositide 3-kinase (PI3K) signaling in pericyte biology during angiogenesis, we used genetic mouse models which allow selective inactivation of PI3Kα and PI3Kβ isoforms and their negative regulator PTEN (phosphate and tensin homologue deleted on chromosome ten, PTEN) in mural cells. Results: At the onset of angiogenesis, pericytes exhibit molecular traits of cell proliferation and activated PI3K signaling, whereas during vascular remodeling pericytes upregulate genes involved in mature pericyte cell function, together with a remarkable decrease in PI3K signaling. Immature pericytes showed stellate shape and high proliferation, and mature pericytes were quiescent and elongated. Unexpectedly, we demonstrate that the PI3Kβ, but not PI3Kα, regulates pericyte proliferation and maturation during vessel formation. Genetic PI3Kβ inactivation in pericytes triggered early pericyte maturation. Conversely, unleashing PI3K signaling by means of PTEN deletion delayed pericyte maturation. Pericyte maturation was necessary to undergo vessel remodeling during angiogenesis. Conclusions: Our results identify new molecular and morphological traits associated to pericyte maturation and uncover PI3Kβ activity as a checkpoint to ensure appropriate vessel formation. In turn, our results may open new therapeutic opportunities to regulate angiogenesis in pathological processes through the manipulation of pericyte PI3Kβ activity.
Background: Pericytes regulate vessel stabilization and function and their loss is associated with diseases such as diabetic retinopathy or cancer. Despite their physiological importance, pericyte function and molecular regulation during angiogenesis remain poorly understood. Methods: To decipher the transcriptomic programs of pericytes during angiogenesis, we crossed the Pdgfrb(BAC)-CreERT2 into the RiboTagflox/flox mice. Pericyte morphological changes were assessed in mural cell-specific R26-mTmG reporter mice, in which low doses of tamoxifen allowed labeling of single cell pericytes at high resolution. To study the role of phosphoinositide 3-kinase (PI3K) signaling in pericyte biology during angiogenesis, we used genetic mouse models which allow selective inactivation of PI3Kα and PI3Kβ isoforms and their negative regulator PTEN (phosphate and tensin homologue deleted on chromosome ten, PTEN) in mural cells. Results: At the onset of angiogenesis, pericytes exhibit molecular traits of cell proliferation and activated PI3K signaling, whereas during vascular remodeling pericytes upregulate genes involved in mature pericyte cell function, together with a remarkable decrease in PI3K signaling. Immature pericytes showed stellate shape and high proliferation, and mature pericytes were quiescent and elongated. Unexpectedly, we demonstrate that the PI3Kβ, but not PI3Kα, regulates pericyte proliferation and maturation during vessel formation. Genetic PI3Kβ inactivation in pericytes triggered early pericyte maturation. Conversely, unleashing PI3K signaling by means of PTEN deletion delayed pericyte maturation. Pericyte maturation was necessary to undergo vessel remodeling during angiogenesis. Conclusions: Our results identify new molecular and morphological traits associated to pericyte maturation and uncover PI3Kβ activity as a checkpoint to ensure appropriate vessel formation. In turn, our results may open new therapeutic opportunities to regulate angiogenesis in pathological processes through the manipulation of pericyte PI3Kβ activity.
Authors: Amanda Krajnik; Joseph A Brazzo; Kalyanaraman Vaidyanathan; Tuhin Das; Javier Redondo-Muñoz; Yongho Bae Journal: Front Cell Dev Biol Date: 2020-12-14