Flow-sensitive HEG1 controls eNOS activity to prevent endothelial dysfunction, hypertension, and atherosclerosis.

Hypertension (HTN), the chronic elevation of blood pressure, accounts for more atherosclerotic cardiovascular disease deaths than any other modifiable risk factor. In the arteries, stable blood flow (s-flow) drives healthy, atheroprotective endothelial cell (EC) functions including nitric oxide (NO) production, barrier function, and anti-inflammatory programs via the action of flow-sensitive proteins. We showed that s-flow stimulates Heart-of-Glass 1 (HEG1) protein expression, localization to cell-cell junctions, and secretion from ECs.

FAK activity exacerbates disturbed flow-mediated atherosclerosis via VEGFR2-CBL-NF-κB signaling.

Atherosclerosis develops at predictable sites in the vasculature where branch points and curvatures create non-laminar disturbed flow. This disturbed flow causes vascular inflammation by increased endothelial cell (EC) barrier permeability and the expression of inflammatory genes such as vascular cell adhesion molecule 1 (VCAM-1). Vascular endothelial growth factor receptor 2 (VEGFR2) regulates flow-induced EC inflammation; however, there are still some gaps in understanding the precise signaling mechanism or pathway.

Lysyl-tRNA synthetase 1 promotes atherogenesis via autophagy-related secretion and inflammation.

Lysyl-tRNA synthetase 1 (KARS1), an aminoacyl-tRNA synthetase, was recently identified as a secreted pro-inflammatory agent. However, the vascular secretion and functions of KARS1 have not been characterized. This study investigated the secretion mechanisms of KARS1 and explored its functional roles in vascular biology.

Disturbed Flow Induces Reprogramming of Endothelial Cells to Immune-like and Foam Cells under Hypercholesterolemia during Atherogenesis.

Background: Atherosclerosis occurs preferentially in the arteries exposed to disturbed flow (d-flow), while the stable flow (s-flow) regions are protected even under hypercholesterolemic conditions. We recently showed that d-flow alone initiates flow-induced reprogramming of endothelial cells (FIRE), including the novel concept of partial endothelial-to-immune-cell-like transition (partial EndIT), but was not validated using a genetic lineage-tracing model. Here, we tested and validated the two-hit hypothesis that d-flow is an initial instigator of partial FIRE but requires hypercholesterolemia to induce a full-blown FIRE and atherosclerotic plaque development.

Disturbed Flow Induces Reprogramming of Endothelial Cells to Immune-like and Foam Cells under Hypercholesterolemia during Atherogenesis.

Background: Atherosclerosis occurs preferentially in the arteries exposed to disturbed flow (d-flow), while the stable flow (s-flow) regions are protected even under hypercholesterolemic conditions. We recently showed that d-flow alone initiates flow-induced reprogramming of endothelial cells (FIRE), including the novel concept of partial endothelial-to-immune-cell-like transition (partial EndIT), but was not validated using a genetic lineage-tracing model. Here, we tested and validated the two-hit hypothesis that d-flow is an initial instigator of partial FIRE but requires hypercholesterolemia to induce a full-blown FIRE and atherosclerotic plaque development.

Inhibiting MiR-33a-3p Expression Fails to Enhance ApoAI-Mediated Cholesterol Efflux in Pro-Inflammatory Endothelial Cells.

: Atherosclerosis is an inflammatory condition that results in cholesterol accumulating within vessel wall cells. Atherosclerotic cardiovascular disease is the leading cause of mortality worldwide due to this disease being a major contributor to myocardial infarctions and cerebrovascular accidents. Research suggests that cholesterol accumulation occurring precisely within arterial endothelial cells triggers atherogenesis and exacerbates atherosclerosis.

Endothelial Cu Uptake Transporter CTR1 Senses Disturbed Flow to Promote Atherosclerosis through Cuproptosis.

Endothelial cells (ECs) lining blood vessels sense disturbed blood flow (D-flow), which drives mitochondrial dysfunction and atherosclerosis. Copper (Cu) is an essential micronutrient, and its disruption of homeostasis has been implicated in atherosclerosis. Cellular Cu levels are tightly controlled by Cu transport proteins including the Cu importer CTR1.

Endothelial cell (EC)-specific Ctgf/Ccn2 expression increases EC reprogramming and atherosclerosis.

Arterial endothelial cells (ECs) reside in a complex biomechanical environment. ECs sense and respond to wall shear stress. Low and oscillatory wall shear stress is characteristic of disturbed flow and commonly found at arterial bifurcations and around atherosclerotic plaques.

Endothelial IGFBP6 suppresses vascular inflammation and atherosclerosis.

Beyond dyslipidemia, inflammation contributes to the development of atherosclerosis. However, intrinsic factors that counteract vascular inflammation and atherosclerosis remain scarce. Here we identify insulin-like growth factor binding protein 6 (IGFBP6) as a homeostasis-associated molecule that restrains endothelial inflammation and atherosclerosis.

Side- and Disease-Dependent Changes in Human Aortic Valve Cell Population and Transcriptomic Heterogeneity Determined by Single-Cell RNA Sequencing.

Background: Calcific aortic valve disease (CAVD) is a highly prevalent disease, especially in the elderly population, but there are no effective drug therapies other than aortic valve repair or replacement. CAVD develops preferentially on the fibrosa side, while the ventricularis side remains relatively spared through unknown mechanisms. We hypothesized that the fibrosa is prone to the disease due to side-dependent differences in transcriptomic patterns and cell phenotypes.

FAK activity exacerbates disturbed flow-mediated atherosclerosis via VEGFR2-Cbl-NF-κB signaling.

Atherosclerosis develops at predictable sites in the vasculature where branch points and curvatures create non-laminar disturbed flow. This disturbed flow causes vascular inflammation by increased endothelial cell (EC) barrier permeability and the expression of inflammatory genes such as vascular cell adhesion molecule-1 (VCAM-1). Vascular endothelial growth factor receptor 2 (VEGFR2) is important for flow-induced EC inflammation; however, there are still some gaps in the signaling pathway.

Saving KLF2/4 from γ-protocadherin to reduce vascular inflammation and atherosclerosis.

Atherosclerosis occurs in arterial regions exposed to disturbed flow, where endothelial expression of flow-sensitive, atheroprotective genes such as and is reduced. Protecting the endothelial expression of KLF2 and KLF4 from inhibitory factors could be a therapeutic approach to prevent vascular inflammation and atherosclerosis.

A renaissance of cerebral cavernous malformation proteins in vascular physiology.

The discovery of the genes causing cerebral cavernous malformation (CCM) initially heralded a fruitful search for etiopathogenic molecular pathways in this rare cerebrovascular disease. Recent studies have identified the relevance of CCM proteins for much more common vascular biology and pathologies.

Hyperoxia impairs induced pluripotent stem cell-derived endothelial cells and drives an atherosclerosis-like transcriptional phenotype.

Background: Induced pluripotent stem cells (iPSCs) directed to endothelial identity (iPSC-ECs) are emerging as a potent tool for regenerative medicine in vascular disease. However, iPSC-ECs lose expression of key identity markers under standard in vitro conditions, limiting their clinical applications.

Methods: To model physiological in vivo conditions, we examined the bioenergetics, presence of key cell markers, and proliferative and angiogenic capacity in iPSC-ECs at late and early passage under hyperoxic (21%) and physiological (4%) oxygen concentrations.

A Biomimetic Leaflet Scaffold for Aortic Valve Remodeling.

Heart valve disease poses a significant clinical challenge, especially in pediatric populations, due to the inability of existing valve replacements to grow or respond biologically to their microenvironment. Tissue-engineered heart valves (TEHVs) provide a solution by facilitating patient-specific models for self-repair and remodeling. In this study, a 3D-bioprinted TEHV is designed to emulate the trilayer leaflet structure of an aortic valve.

Disturbed flow regulates protein disulfide isomerase A1 expression via microRNA-204.

Redox processes can modulate vascular pathophysiology. The endoplasmic reticulum redox chaperone protein disulfide isomerase A1 (PDIA1) is overexpressed during vascular proliferative diseases, regulating thrombus formation, endoplasmic reticulum stress adaptation, and structural remodeling. However, both protective and deleterious vascular effects have been reported for PDIA1, depending on the cell type and underlying vascular condition.

Simulated microgravity improves maturation of cardiomyocytes derived from human induced pluripotent stem cells.

Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) possess tremendous potential for basic research and translational application. However, these cells structurally and functionally resemble fetal cardiomyocytes, which is a major limitation of these cells. Microgravity can significantly alter cell behavior and function.

EMID2 is a novel biotherapeutic for aggressive cancers identified by in vivo screening.

Background: New drugs to tackle the next pathway or mutation fueling cancer are constantly proposed, but 97% of them are doomed to fail in clinical trials, largely because they are identified by cellular or in silico screens that cannot predict their in vivo effect.

Methods: We screened an Adeno-Associated Vector secretome library (> 1000 clones) directly in vivo in a mouse model of cancer and validated the therapeutic effect of the first hit, EMID2, in both orthotopic and genetic models of lung and pancreatic cancer.

Results: EMID2 overexpression inhibited both tumor growth and metastatic dissemination, consistent with prolonged survival of patients with high levels of EMID2 expression in the most aggressive human cancers.

Atherosclerotic three-layer nanomatrix vascular sheets for high-throughput therapeutic evaluation.

In vitro atherosclerosis models are essential to evaluate therapeutics before in vivo and clinical studies, but significant limitations remain, such as the lack of three-layer vascular architecture and limited atherosclerotic features. Moreover, no scalable 3D atherosclerosis model is available for making high-throughput assays for therapeutic evaluation. Herein, we report an in vitro 3D three-layer nanomatrix vascular sheet with critical atherosclerosis multi-features (VSA), including endothelial dysfunction, monocyte recruitment, macrophages, extracellular matrix remodeling, smooth muscle cell phenotype transition, inflammatory cytokine secretion, foam cells, and calcification initiation.

HEG1 Protects Against Atherosclerosis by Regulating Stable Flow-Induced KLF2/4 Expression in Endothelial Cells.

Background: Atherosclerosis preferentially occurs in arterial regions of disturbed blood flow, and stable flow (s-flow) protects against atherosclerosis by incompletely understood mechanisms.

Methods: Our single-cell RNA-sequencing data using the mouse partial carotid ligation model was reanalyzed, which identified Heart-of-glass 1 (HEG1) as an s-flow-induced gene. HEG1 expression was studied by immunostaining, quantitive polymerase chain reaction, hybridization chain reaction, and Western blot in mouse arteries, human aortic endothelial cells (HAECs), and human coronary arteries.

Blood flow patterns switch VEGFR2 activity through differential S-nitrosylation and S-oxidation.

Vascular endothelial growth factor receptor-2 (VEGFR2) plays a key role in maintaining vascular endothelial homeostasis. Here, we show that blood flows determine activation and inactivation of VEGFR2 through selective cysteine modifications. VEGFR2 activation is regulated by reversible oxidation at Cys residue.

Nanodiscoidal Nucleic Acids for Gene Regulation.

Therapeutic nucleic acids represent a powerful class of drug molecules to control gene expression and protein synthesis. A major challenge in this field is that soluble oligonucleotides have limited serum stability, and the majority of nucleic acids that enter the cells are trapped within endosomes. Delivery efficiency can be improved using lipid scaffolds.