Biology subjects

Serbanovic-Canic, J.

Publications and source records attributed to Serbanovic-Canic, J..

5 recordsLinked to original sources

bioRxiv2025

TWIST1 drives endothelial-to-mesenchymal-transition to stabilize atherosclerotic plaques

Atherosclerosis progresses from fatty streaks to complex plaques, with rupture leading to life-threatening complications. Endothelial-to-mesenchymal transition (EndMT) is associated with advanced atherosclerotic plaques, but its role in plaque progression remains unclear. To investigate this, we analyzed the role of TWIST1, a key EndMT-driving transcription factor, in plaque development. Using single-cell RNA sequencing of atherosclerotic plaques from hypercholesterolemic mice with inducible deletion of Twist1 from endothelial cells (Twist1ECKO ApoE-/-) we demonstrate that Twist1 regulates endothelial cell heterogeneity by promoting cell states expressing EndMT markers. Cell tracking confirmed that Twist1 induces EndMT in advanced plaques. Mechanistically, we found that TWIST1 contributes to EndMT by promoting endothelial migration and proliferation through the transcriptional coactivator PELP1. Additionally, TWIST1 induces AEBP1 transcription, which upregulates COL4A1 to drive endothelial proliferation. Analyses of murine brachiocephalic plaques show that endothelial Twist1 promotes plaque growth, collagen deposition, and ACTA2-positive cell accumulation, hallmarks of plaque stability, while reducing necrosis and macrophage infiltration, features of plaque instability. Moreover, TWIST1 expression was associated with asymptomatic human carotid atherosclerosis and predicts favourable clinical outcomes. These findings challenge the prevailing view that EndMT destabilizes plaques, by suggesting that TWIST1-driven EndMT can promote plaque stability, offering new insights into atherosclerosis pathophysiology and therapeutic potential.

pathology↗

bioRxiv2023

EPAS1 Attenuates Atherosclerosis Initiation at Disturbed Flow Sites through Endothelial Fatty Acid Uptake

BackgroundAtherosclerotic plaques form unevenly due to disturbed blood flow, causing localized endothelial cell (EC) dysfunction. Obesity exacerbates this process, but the underlying molecular mechanisms are unclear. The transcription factor EPAS1 (HIF2A) has regulatory roles in endothelium, but its involvement in atherosclerosis remains unexplored. This study investigates the potential interplay between EPAS1, obesity, and atherosclerosis. MethodsResponses to shear stress were analysed using cultured porcine aortic EC exposed to flow in vitro coupled with metabolic and molecular analyses, and by en face immunostaining of murine aortic EC exposed to disturbed flow in vivo. Obesity and dyslipidemia were induced in mice via exposure to high-fat diet or through Leptin gene deletion. The role of Epas1 in atherosclerosis was evaluated by inducible endothelial Epas1 deletion, followed by hypercholesterolemia induction (AAV-PCSK9; high-fat diet). ResultsEn face staining revealed EPAS1 enrichment at sites of disturbed blood flow that are prone to atherosclerosis initiation. Obese mice exhibited substantial reduction in endothelial EPAS1 expression, correlating with hyperlipidaemia. Sulforaphane, a compound with known atheroprotective effects, restored EPAS1 expression and concurrently reduced plasma triglyceride levels in obese mice. Consistently, triglyceride derivatives (free fatty acids) suppressed EPAS1 in cultured EC by upregulating the negative regulator PHD3. Clinical observations revealed that reduced plasma EPAS1 correlated with increased endothelial PHD3 in obese individuals. Functionally, endothelial EPAS1 deletion increased lesion formation in hypercholesterolemic mice, indicating an atheroprotective function. Mechanistic insights revealed that EPAS1 protects arteries by maintaining endothelial proliferation by positively regulating CD36 and LIPG expression to increase fatty acid beta-oxidation. ConclusionsEndothelial EPAS1 attenuates atherosclerosis at sites of disturbed flow by maintaining EC proliferative via fatty acid uptake and metabolism. This endothelial repair pathway is inhibited in obesity, suggesting a novel triglyceride-PHD3 modulation pathway suppressing EPAS1 expression. These findings have implications for therapeutic strategies addressing vascular dysfunction in obesity.

physiology↗

bioRxiv2020

The effect of absent blood flow on the zebrafish cerebral and trunk vasculature

The role of blood flow is complex and context-dependent. In this study, we quantify the effect of the lack of blood flow on vascular development and compare its impact in two vascular beds, namely the cerebral and trunk vasculature, using zebrafish as preclinical model. We performed this by analysing vascular topology, endothelial cell number, apoptosis, and inflammatory response in animals with normal blood flow or absent blood flow. We find that absent blood flow reduced vascular area and endothelial cell number significantly in both examined vascular beds, but the effect is more severe in the cerebral vasculature. Similarly, while stereotypic vascular patterning in the trunk is maintained, intra-cerebral vessels show altered patterning. Absent blood flow lead to an increase in non-EC-specific apoptosis without increasing tissue inflammation, as quantified by cerebral immune cell numbers and nitric oxide. In conclusion, blood flow is essential for cellular survival in both the trunk and cerebral vasculature, but particularly intra-cerebral vessels are affected by the lack of blood flow, suggesting that responses to blood flow differ between these two vascular beds. Key pointsO_LIWe here use zebrafish as a model to quantitatively assess the impact of the lack of blood flow in development and compare its impact in two vascular beds, namely the cerebral to trunk vasculature. C_LIO_LIIn both vascular beds, vascular growth and endothelial cell number are reduced by lack of blood flow, with increasing effect size from 2-5 days post fertilisation. C_LIO_LIExamination of vascular patterning shows that while stereotypic patterning in the trunk is preserved, the intra-cerebral vasculature patterning is altered. C_LIO_LIWe found non-EC-specific cell death to be increased in both vascular beds, with a larger effect size in the brain, but that this cell death occurs without triggering tissue inflammation. C_LI

developmental biology↗

bioRxiv2020

JAG1-NOTCH4 MECHANOSENSING DRIVES ATHEROSCLEROSIS

Endothelial cell (EC) sensing of fluid shear stress regulates atherosclerosis, a disease of arteries that causes heart attack and stroke. Atherosclerosis preferentially develops at regions of arteries exposed to low oscillatory shear stress (LOSS), whereas high shear regions are protected. We show using inducible EC-specific genetic deletion in hyperlipidaemic mice that the Notch ligands JAG1 and DLL4 have opposing roles in atherosclerosis. While endothelial Jag1 promoted atherosclerosis at sites of LOSS, endothelial Dll4 was atheroprotective. Analysis of porcine and murine arteries and cultured human coronary artery EC exposed to experimental flow revealed that JAG1 and its receptor NOTCH4 are strongly upregulated by LOSS. Functional studies in cultured cells and in mice with EC-specific deletion of Jag1 show that JAG1-NOTCH4 signalling drives vascular dysfunction by repressing endothelial repair. These data demonstrate a fundamental role for JAG1-NOTCH4 in sensing LOSS during disease, and suggest therapeutic targeting of this pathway to treat atherosclerosis.Competing Interest StatementThe authors have declared no competing interest.View Full Text

pathology↗

bioRxiv2019

β1 integrin is a sensor of blood flow direction

The ability of endothelial cells (EC) to sense blood flow direction is a critical determinant of vascular health and disease. Unidirectional flow induces EC alignment and vascular homeostasis, whereas bidirectional flow has pathophysiological effects. EC express several mechanoreceptors that can respond to fluid flow (shear stress) but the mechanism for sensing the direction of shearing force is poorly understood. We observed using in vitro flow systems and magnetic tweezers that {beta}1 integrin is a key sensor of force direction because it is activated by unidirectional but not bidirectional shearing forces. Consistently, {beta}1 integrin was essential for Ca2+ signalling and cell alignment in response to unidirectional but not bidirectional shear stress. {beta}1 integrin activation by unidirectional force was amplified in EC that were pre-sheared in the same direction, indicating that alignment and {beta}1 integrin activity has a feedforward interaction which is a hallmark of system stability. En face staining and EC-specific genetic deletion studies of the murine aorta revealed that {beta}1 integrin is activated and is essential for EC alignment at sites of unidirectional flow but is not activated at sites of bidirectional flow. In summary, {beta}1 integrin sensing of unidirectional force is a key mechanism for decoding blood flow mechanics to promote vascular homeostasis.\n\nSUMMARY STATEMENTWe demonstrate using flow systems, magnetic tweezers and knockout mice that {beta}1 integrin is a sensor of shear stress direction in endothelial cells. {beta}1 integrin is activated by unidirectional hemodynamic shear force leading to calcium signalling and cell alignment, but it is not activated by bidirectional force.

cell biology↗