Biology subjects

Mammoto, A.

Publications and source records attributed to Mammoto, A..

3 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↗

bioRxiv2019

Molecular mapping of transmembrane mechanotransduction through the β1 integrin-CD98hc-TRPV4 axis

One of the most rapid (< 4 msec) transmembrane cellular mechanotransduction events involves activation of Transient Receptor Potential Vanilloid 4 (TRPV4) ion channels by mechanical forces transmitted across {beta}1 integrin receptors in endothelial cells, and the transmembrane Solute Carrier family 3 member 2 (CD98hc) protein has been implicated in this response. Here, we show that {beta}1 integrin, CD98hc, and TRPV4 all tightly associate and co-localize in focal adhesions where mechanochemical conversion takes place. CD98hc knock down inhibits TRPV4-mediated calcium influx induced by mechanical forces, but not by chemical activators, thus confirming the mechanospecificity of this signaling response. Molecular analysis revealed that forces applied to {beta}1 integrin must be transmitted from its cytoplasmic C-terminus to the CD98hc cytoplasmic tail, and from there to the ankyrin repeat domain of TRPV4 in order to produce ultra-rapid, force-induced, channel activation within the focal adhesion.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=153 SRC=\"FIGDIR/small/617092v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (44K):\norg.highwire.dtl.DTLVardef@11bfb51org.highwire.dtl.DTLVardef@10bcdaorg.highwire.dtl.DTLVardef@debf89org.highwire.dtl.DTLVardef@1f0bee5_HPS_FORMAT_FIGEXP M_FIG Graphical abstract\n\nC_FIG SUMMARYA direct path of mechanical signal transfer between {beta}1 integrin, CD98hc, and TRPV4 channels is identified that mediates ultra-rapid transmembrane mechanochemical conversion within focal adhesions.

cell biology↗