Biology subjects

Abello, J.

Publications and source records attributed to Abello, J..

5 recordsLinked to original sources

bioRxiv2024

Endothelial cell Piezo1 promotes vascular smooth muscle cell differentiation on large arteries

Vascular stabilization is a mechanosensitive process, in part driven by blood flow. Here, we demonstrate the involvement of the mechanosensitive ion channel, Piezo1, in promoting arterial accumulation of vascular smooth muscle cells (vSMCs) during zebrafish development. Using a series of small molecule antagonists or agonists to temporally regulate Piezo1 activity, we identified a role for the Piezo1 channel in regulating klf2a levels and altered targeting of vSMCs between arteries and veins. Increasing Piezo1 activity suppressed klf2a and increased vSMC association with the cardinal vein, while inhibition of Piezo1 activity increased klf2a levels and decreased vSMC association with arteries. We supported the small molecule data with in vivo genetic suppression of piezo1 and 2 in zebrafish, resulting in loss of transgelin+ vSMCs on the dorsal aorta. Further, endothelial cell (EC)-specific Piezo1 knockout in mice was sufficient to decrease vSMC accumulation along the descending dorsal aorta during development, thus phenocopying our zebrafish data, and supporting functional conservation of Piezo1 in mammals. To determine mechanism, we used in vitro modeling assays to demonstrate that differential sensing of pulsatile versus laminar flow forces across endothelial cells changes the expression of mural cell differentiation genes. Together, our findings suggest a crucial role for EC Piezo1 in sensing force within large arteries to mediate mural cell differentiation and stabilization of the arterial vasculature.

developmental biology↗

bioRxiv2023

Hemodynamics regulate spatiotemporal artery muscularization in the developing circle of Willis

Vascular smooth muscle cells (VSMCs) envelop vertebrate brain arteries, playing a crucial role in regulating cerebral blood flow and neurovascular coupling. The dedifferentiation of VSMCs is implicated in cerebrovascular diseases and neurodegeneration. Despite its importance, the process of VSMC differentiation on brain arteries during development remains inadequately characterized. Understanding this process could aid in reprogramming and regenerating differentiated VSMCs in cerebrovascular diseases. In this study, we investigated VSMC differentiation on the zebrafish circle of Willis (CoW), comprising major arteries that supply blood to the vertebrate brain. We observed that the arterial expression of CoW endothelial cells (ECs) occurs after their migration from the cranial venous plexus to form CoW arteries. Subsequently, acta2+ VSMCs differentiate from pdgfrb+ mural cell progenitors upon recruitment to CoW arteries. The progression of VSMC differentiation exhibits a spatiotemporal pattern, advancing from anterior to posterior CoW arteries. Analysis of blood flow suggests that earlier VSMC differentiation in anterior CoW arteries correlates with higher red blood cell velocity wall shear stress. Furthermore, pulsatile blood flow is required for differentiation of human brain pdgfrb+ mural cells into VSMCs as well as VSMC differentiation on zebrafish CoW arteries. Consistently, the flow-responsive transcription factor klf2a is activated in ECs of CoW arteries prior to VSMC differentiation, and klf2a knockdown delays VSMC differentiation on anterior CoW arteries. In summary, our findings highlight the role of blood flow activation of endothelial klf2a as a mechanism regulating the initial VSMC differentiation on vertebrate brain arteries.

developmental biology↗

bioRxiv2023

CXCR3-CXCL11 signaling restricts angiogenesis and promotes pericyte recruitment

Endothelial cell (EC)-pericyte interactions are known to remodel in response to hemodynamic forces, yet there is a lack of mechanistic understanding of the signaling pathways that underlie these events. Here, we have identified a novel signaling network regulated by blood flow in ECs--the chemokine receptor, CXCR3, and one of its ligands, CXCL11--that delimits EC angiogenic potential and suppresses pericyte recruitment during development through regulation of pdgfb expression in ECs. In vitro modeling of EC-pericyte interactions demonstrates that suppression of EC-specific CXCR3 signaling leads to loss of pericyte association with EC tubes. In vivo, phenotypic defects are particularly noted in the cranial vasculature, where we see a loss of pericyte association with and expansion of the vasculature in zebrafish treated with the Cxcr3 inhibitor AMG487. We also demonstrate using flow modeling platforms that CXCR3-deficient ECs are more elongated, move more slowly, and have impaired EC-EC junctions compared to their control counterparts. Together these data suggest that CXCR3 signaling in ECs drives vascular stabilization events during development.

developmental biology↗

bioRxiv2021

Adaptation of peristaltic pumps for laminar flow experiments

Endothelial cells (ECs) are the primary cellular constituent of blood vessels that are in direct contact with hemodynamic forces over the course of a lifetime. Throughout the body, vessels experience different types of blood flow patterns and rates that alter vascular architecture and cellular behavior. Because of the complexities of studying blood flow in an intact organism, particularly during development, modeling of blood flow in vitro has become a powerful technique for studying hemodynamic dependent signaling mechanisms in ECs. While commercial flow systems that recirculate fluids exist, many commercially available pumps are peristaltic and best model pulsatile flow conditions. However, there are many important in vivo situations in which ECs experience laminar flow conditions, such as along long, straight stretches of the vasculature. To understand EC function under these situations, it is important to be able to consistently model laminar flow conditions in vitro. Here, we outline a method to reliably adapt commercially available peristaltic pumps to reproducibly study laminar flow conditions. Our proof of concept study focuses on 2-dimensional (2D) models but could be further adapted to 3-dimensional (3D) environments to better model in vivo scenarios such as organ development. Our studies make significant inroads into solving technical challenges associated with flow modeling, and allow us to conduct functional studies towards understanding the mechanistic role of flow forces on vascular architecture, cellular behavior, and remodeling during a variety of physiological contexts.

cell biology↗

bioRxiv2020

The SWELL1-LRRC8 complex regulates endothelial AKT-eNOS-mTOR signaling and vascular function

The endothelium responds to a multitude of chemical and mechanical factors in regulating vascular tone, angiogenesis, blood pressure and blood flow. The endothelial volume regulatory anion channel (VRAC) has been proposed to be mechano-sensitive, to activate in response to fluid flow/hydrostatic pressure and putatively regulate vascular reactivity and angiogenesis. Here, we show that the Leucine Rich Repeat Containing Protein 8a, LRRC8a (SWELL1) functionally encodes VRAC in human umbilical vein endothelial cells (HUVECs). Endothelial SWELL1 (SWELL1) expression positively regulates AKT-eNOS signaling while negatively regulating mTOR signaling, via a SWELL1-GRB2-Cav1-eNOS signaling complex. Endothelium-restricted SWELL1 KO (SWELL1 KO) mice exhibit enhanced tube formation from ex-vivo aortic ring explants in matrigel angiogenesis assays, develop hypertension in response to chronic angiotensin II infusion and have impaired retinal blood flow with both diffuse and focal blood vessel narrowing in the setting of Type 2 diabetes (T2D). These data demonstrate that SWELL1 antithetically regulates AKT-eNOS and mTOR signaling in endothelium and is required for maintaining vascular function, particularly in the setting of T2D.

cell biology↗