Contribution of PDGFRα-positive cells in maintenance and injury responses in mouse large vessels

AbstractThe maladaptive remodeling of vessel walls with neointima formation is a common feature of proliferative vascular diseases. It has been proposed that neointima formation is caused by the dedifferentiation of mature smooth muscle cells (SMCs). Recent evidence suggests that adventitial cells also participate in neointima formation; however, their cellular dynamics are not fully understood. In this study, we utilized a lineage tracing model of platelet-derived growth factor receptor alpha (PDGFRa) cells and examined cellular behavior during homeostasis and injury response. PDGFRa marked adventitial cells that were largely positive for Sca1 and a portion of medial SMCs, and both cell types were maintained for 2 years. Upon carotid artery ligation, PDGFRa-positive (+) cells were slowly recruited to the neointima and exhibited an immature SMC phenotype. In contrast, in a more severe wire denudation injury, PDGFRa+ cells were recruited to the neointima within 14 days and fully differentiated into SMCs. Under pressure overload induced by transverse aortic constriction, PDGFRa+ cells developed marked adventitial fibrosis. Taken together, our observations suggest that PDGFRa+ cells serve as a reservoir of adventitial cells and a subset of medial SMCs and underscore their context-dependent response to vascular injuries.

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Abstract 92: Platelet Derived Growth Factor Receptor Alpha Signaling is Required for Cardiac Fibroblast Survival and Proliferation

Circulation Research ◽

10.1161/res.119.suppl_1.92 ◽

2016 ◽

Vol 119 (suppl_1) ◽

Author(s):

Malina J Ivey ◽

Michelle D Tallquist

Keyword(s):

Preliminary Data ◽

Cardiac Fibrosis ◽

Heart Function ◽

Cardiac Fibroblasts ◽

Growth Factor Receptor ◽

Cell Types ◽

Fibroblast Proliferation ◽

Artery Ligation ◽

Developing Heart ◽

Factor Receptor Alpha

Cardiac fibrosis contributes significantly to heart disease and is a hallmark of decreased cardiac function. Currently, there are no treatments that attenuate fibrosis, but identification of signaling pathways required for fibroblast function would provide some potential targets. PDGFRα is a receptor tyrosine kinase that is required for fibroblast formation in the developing heart, and preliminary data indicates that it is also required for maintenance of resident fibroblasts and expansion of activated fibroblasts after injury. Preliminary experiments demonstrate that loss of PDGFRα expression in adult cardiac fibroblasts results in 50% reduction in the number of the resident fibroblasts by 4 days after gene deletion. This was further validated using an independent fibroblast marker, collagen1a1GFP. Based on the low basal level of fibroblast proliferation, we hypothesize that PDGFRα signaling is essential for fibroblast survival and that fibroblasts undergo rapid turnover in the absence of PDGFRα signaling. Future studies will determine the exact mechanism of this loss. We have also begun to elucidate which PDGFRα downstream signals promote fibroblast maintenance. Using a PDGFRα-dependent-PI3K-deficient mouse model, preliminary data indicates that PDGFRα-dependent PI3K signaling is essential for cell survival. We are also investigating the role of PDGFRα signaling after myocardial infarction. Using recently described genetic tools to follow fibroblasts after injury, we have determined that fibroblasts reach their peak of proliferation within a week after permanent left anterior descending artery ligation. This injury-induced proliferation is reduced by 50% after deletion of PDGFRα. Therefore, we have demonstrated that PDGFRα has a role in fibroblast maintenance in the healthy heart, as well as a role in fibroblast proliferation after injury. Our studies will continue to illuminate additional roles for PDGFRα in the fibroblast, as well as the implications of fibroblast loss on other cell types and overall heart function.

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Extracellular matrix protein CCN1 induced by disturbed flow in the carotid-artery-ligation mouse model promotes neointima formation through integrin A6B1

Atherosclerosis ◽

10.1016/j.atherosclerosis.2015.04.091 ◽

2015 ◽

Vol 241 (1) ◽

pp. e22-e23

Author(s):

P.L. Hsu ◽

J.S. Chen ◽

F.E. Mo

Keyword(s):

Extracellular Matrix ◽

Carotid Artery ◽

Mouse Model ◽

Matrix Protein ◽

Extracellular Matrix Protein ◽

Neointima Formation ◽

Artery Ligation ◽

Disturbed Flow ◽

Carotid Artery Ligation

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Inhibitory Effect of a Glutamine Antagonist on Proliferation and Migration of VSMCs via Simultaneous Attenuation of Glycolysis and Oxidative Phosphorylation

International Journal of Molecular Sciences ◽

10.3390/ijms22115602 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5602

Author(s):

Hyeon Young Park ◽

Mi-Jin Kim ◽

Seunghyeong Lee ◽

Jonghwa Jin ◽

Sungwoo Lee ◽

...

Keyword(s):

Mammalian Target Of Rapamycin ◽

Inhibitory Effect ◽

Metabolic Reprogramming ◽

Neointima Formation ◽

Artery Ligation ◽

Carotid Artery Ligation ◽

And Migration ◽

Proliferation And Migration

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to the development of atherosclerosis and restenosis. Glycolysis and glutaminolysis are increased in rapidly proliferating VSMCs to support their increased energy requirements and biomass production. Thus, it is essential to develop new pharmacological tools that regulate metabolic reprogramming in VSMCs for treatment of atherosclerosis. The effects of 6-diazo-5-oxo-L-norleucine (DON), a glutamine antagonist, have been broadly investigated in highly proliferative cells; however, it is unclear whether DON inhibits proliferation of VSMCs and neointima formation. Here, we investigated the effects of DON on neointima formation in vivo as well as proliferation and migration of VSMCs in vitro. DON simultaneously inhibited FBS- or PDGF-stimulated glycolysis and glutaminolysis as well as mammalian target of rapamycin complex I activity in growth factor-stimulated VSMCs, and thereby suppressed their proliferation and migration. Furthermore, a DON-derived prodrug, named JHU-083, significantly attenuated carotid artery ligation-induced neointima formation in mice. Our results suggest that treatment with a glutamine antagonist is a promising approach to prevent progression of atherosclerosis and restenosis.

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Cryo-Electron Microscopy Structure and Interactions of the Human Cytomegalovirus gHgLgO Trimer with Platelet-Derived Growth Factor Receptor Alpha

mBio ◽

10.1128/mbio.02625-21 ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

Jing Liu ◽

Adam Vanarsdall ◽

Dong-Hua Chen ◽

Andrea Chin ◽

David Johnson ◽

...

Keyword(s):

Birth Defects ◽

Adult Population ◽

Growth Factor Receptor ◽

Cell Types ◽

The Body ◽

Platelet Derived Growth Factor ◽

Cryo Electron Microscopy ◽

Factor Receptor Alpha ◽

Complex Protein ◽

Different Cell Types

HCMV is a herpesvirus that infects a large percentage of the adult population and causes significant levels of disease in immunocompromised individuals and birth defects in the developing fetus. The virus encodes a complex protein machinery that coordinates infection of different cell types in the body, including a trimer formed of gH, gL, and gO subunits.

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Pathogen at the Gates: Human Cytomegalovirus Entry and Cell Tropism

10.20944/preprints201811.0378.v2 ◽

2018 ◽

Cited By ~ 2

Author(s):

Christopher C. Nguyen ◽

Jeremy P. Kamil

Keyword(s):

Human Cytomegalovirus ◽

Wide Spectrum ◽

Growth Factor Receptor ◽

Cell Types ◽

Stable Complex ◽

Cell Tropism ◽

The Past ◽

Factor Receptor Alpha ◽

Glycoprotein H ◽

Substantial Progress

The past few years have brought substantial progress toward understanding how human cytomegalovirus (HCMV) enters the remarkably wide spectrum of cell types and tissues that the virus infects. Neuropilin-2 and platelet-derived growth factor receptor alpha (PDGFRa) were identified as receptors, respectively, for the trimeric and pentameric glycoprotein H/glycoprotein L (gH/gL) complexes that in large part govern HCMV cell tropism, while CD90 and CD147 were also found to play roles during entry. X-ray crystal structures for the proximal viral fusogen, glycoprotein B (gB), and for the pentameric gH/gL complex (pentamer) have been solved. A novel virion gH complex consisting of gH bound to UL116 instead of gL was described, and findings supporting the existence of a stable complex between gH/gL and gB were reported. Additional work indicates that the pentamer promotes a mode of cell-associated spread that resists antibody neutralization, as opposed to the trimeric gH/gL complex (trimer), which appears to be broadly required for the infectivity of cell-free virions. Finally, viral factors such as UL148 and US16 were identified that can influence the incorporation of the alternative gH/gL complexes into virions. We will review these advances and their implications for understanding HCMV entry and cell tropism.

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Pathogen at the Gates: HCMV Entry and Cell Tropism

10.20944/preprints201811.0378.v1 ◽

2018 ◽

Author(s):

Christopher C. Nguyen ◽

Jeremy P. Kamil

Keyword(s):

Wide Spectrum ◽

Growth Factor Receptor ◽

Cell Types ◽

Stable Complex ◽

Cell Tropism ◽

X Ray ◽

The Past ◽

Factor Receptor Alpha ◽

Glycoprotein H ◽

Substantial Progress

The past few years have brought substantial progress toward understanding how human cytomegalovirus (HCMV) enters the remarkably wide spectrum of cell types and tissues that the virus is observed to infect.  Neuropilin-2 and platelet-derived growth factor receptor alpha (PDGFRα) were identified as receptors, respectively, for the trimeric and pentameric glycoprotein H / glycoprotein L (gH/gL) complexes that in large part govern HCMV cell tropism, while CD90 and CD147 were also found to play roles during entry.  X-ray crystal structures for the proximal viral fusogen, glycoprotein B (gB), and for the pentameric gH/gL complex (pentamer) were solved.  A novel virion gH complex consisting of gH bound to UL116 instead of gL was described, and findings supporting the existence of a stable complex between gH/gL and gB were reported.  Additional work indicates that the pentamer promotes a mode of cell-associated spread that resists antibody neutralization, as opposed to the trimeric gH/gL complex (trimer), which appears to be broadly required for the infectivity of cell-free virions.  Finally, viral factors such as UL148 and US16 were identified that can influence the incorporation of the alternative gH/gL complexes into virions.  We will review these advances and their implications for understanding HCMV entry and cell tropism.

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Regenerating vascular mural cells in zebrafish fin blood vessels are not derived from pre-existing ones and differentially require pdgfrb signaling for their development

10.1101/2021.03.27.437334 ◽

2021 ◽

Author(s):

Arndt F Siekmann ◽

Elvin Vincent Leonard ◽

Ricardo Figueroa ◽

Jeroen Bussmann ◽

Julio D Amigo ◽

...

Keyword(s):

Endothelial Cells ◽

Smooth Muscle ◽

Tissue Regeneration ◽

Growth Factor Receptor ◽

Cell Types ◽

Lineage Tracing ◽

The Body ◽

Mural Cell ◽

Caudal Fin ◽

Mural Cells

Vascular networks are comprised of endothelial cells and mural cells, which include pericytes and smooth muscle cells. It is well established that new endothelial cells are derived from pre-existing ones during the angiogenic phase of blood vessel growth. By contrast, mural cell ontogeny is less clear with an ongoing debate whether mural cells possess mesenchymal stem cell properties. To elucidate the mechanisms controlling mural cell recruitment during development and tissue regeneration, we studied the formation of zebrafish caudal fin arteries. Mural cells showed morphological heterogeneity: cells colonizing arteries proximal to the body wrapped around them, while those in more distal regions extended protrusions along the proximo-distal vascular axis. Despite these differences, both cell populations expressed platelet-derived growth factor receptor beta (Pdgfrb) and the smooth muscle cell marker myosin heavy chain 11a (Myh11a). Loss of Pdgfrb signalling during development or tissue regeneration resulted in a substantial decrease in mural cells at the vascular front, while those proximal to the body were less affected. Using lineage tracing, we demonstrate that precursor cells located in periarterial regions of the caudal fin and expressing Pgdfrb can give rise to mural cells, while in regeneration newly formed mural cells were not derived from pre-existing ones. Together, our findings reveal conserved roles for pdgfrb signalling in development and regeneration, while at the same time illustrating a limited capacity of mural cells to self-renew or contribute to other cell types during tissue regeneration.

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Three-Dimensional Imaging Provides Detailed Atherosclerotic Plaque Morphology and Reveals Angiogenesis After Carotid Artery Ligation

Circulation Research ◽

10.1161/circresaha.119.315804 ◽

2020 ◽

Vol 126 (5) ◽

pp. 619-632 ◽

Cited By ~ 5

Author(s):

Tobias Becher ◽

Dario F. Riascos-Bernal ◽

Daniel J. Kramer ◽

Vanessa M. Almonte ◽

Jingy Chi ◽

...

Keyword(s):

Carotid Artery ◽

Mouse Models ◽

Light Sheet ◽

Volumetric Analysis ◽

Neointima Formation ◽

Plaque Volume ◽

Artery Ligation ◽

Light Sheet Microscopy ◽

Carotid Artery Ligation ◽

Brachiocephalic Arteries

Rationale: Remodeling of the vessel wall and the formation of vascular networks are dynamic processes that occur during mammalian embryonic development and in adulthood. Plaque development and excessive neointima formation are hallmarks of atherosclerosis and vascular injury. As our understanding of these complex processes evolves, there is a need to develop new imaging techniques to study underlying mechanisms. Objective: We used tissue clearing and light-sheet microscopy for 3-dimensional (3D) profiling of the vascular response to carotid artery ligation and induction of atherosclerosis in mouse models. Methods and Results: Adipo-Clear and immunolabeling in combination with light-sheet microscopy were applied to image carotid arteries and brachiocephalic arteries, allowing for 3D reconstruction of vessel architecture. Entire 3D neointima formations with different geometries were observed within the carotid artery and scored by volumetric analysis. Additionally, we identified a CD31-positive adventitial plexus after ligation of the carotid artery that evolved and matured over time. We also used this method to characterize plaque extent and composition in the brachiocephalic arteries of ApoE-deficient mice on high-fat diet. The plaques exhibited inter-animal differences in terms of plaque volume, geometry, and ratio of acellular core to plaque volume. A 3D reconstruction of the endothelium overlying the plaque was also generated. Conclusions: We present a novel approach to characterize vascular remodeling in adult mice using Adipo-Clear in combination with light-sheet microscopy. Our method reconstructs 3D neointima formation after arterial injury and allows for volumetric analysis of remodeling, in addition to revealing angiogenesis and maturation of a plexus surrounding the carotid artery. This method generates complete 3D reconstructions of atherosclerotic plaques and uncovers their volume, geometry, acellular component, surface, and spatial position within the brachiocephalic arteries. Our approach may be used in a number of mouse models of cardiovascular disease to assess vessel geometry and volume. Visual Overview: An online visual overview is available for this article.

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