spatial-quantification-drugs-pulmonary-tuberculosis-lesions-laser

Spatial Quantification of Drugs in Pulmonary Tuberculosis Lesions by Laser Capture Microdissection Liquid Chromatography Mass Spectrometry (LCM-LC/MS)

Tuberculosis is still a leading cause of morbidity and mortality worldwide. Improvements to existing drug regimens and the development of novel ...

imaging-analysis-oil-red-o-stained-whole-aorta-lesions-an-aneurysm

Imaging and Analysis of Oil Red O-Stained Whole Aorta Lesions in an Aneurysm Hyperlipidemia Mouse Model

Apolipoprotein E (Apoe)- or low density lipoprotein receptor (Ldlr)-deficient hyperlipidemic mice are the two most commonly used models for ...

multiple-intravenous-bolus-dosing-invasive-hemodynamic-assessment

Multiple Intravenous Bolus Dosing and Invasive Hemodynamic Assessment in a Hypoxia-Induced Mouse Pulmonary Artery Hypertension Model

Pulmonary arterial hypertension (PAH) is a progressive life-threatening disease, primarily affecting small pulmonary arterioles of the lung. Currently, ...

Rutgers, the State University of New Jersey

Yale University School of Medicine

Atherosclerosis is a progressive vascular disease triggered by interplay between abnormal shear stress and endothelial lipid retention. A combination of these and, potentially, other factors leads to a chronic inflammatory response in the vessel wall, which is thought to be responsible for disease progression characterized by a buildup of atherosclerotic plaques. Yet molecular events responsible for maintenance of plaque inflammation and plaque growth have not been fully defined. Here we show that endothelial TGFβ signaling is one of the primary drivers of atherosclerosis-associated vascular inflammation. Inhibition of endothelial TGFβ signaling in hyperlipidemic mice reduces vessel wall inflammation and vascular permeability and leads to arrest of disease progression and regression of established lesions. These pro-inflammatory effects of endothelial TGFβ signaling are in stark contrast with its effects in other cell types and identify it as an important driver of atherosclerotic plaque growth and show the potential of cell-type specific therapeutic intervention aimed at control of this disease.

Endothelial TGF-β signalling drives vascular inflammation and atherosclerosis.

Vascular smooth muscle cells (VSMC) exhibit phenotypic plasticity and change from a quiescent contractile phenotype to a proliferative synthetic phenotype during physiological arteriogenesis and pathological conditions such as atherosclerosis and restenosis. Platelet-derived growth factor (PDGF)-BB is a potent inducer of the VSMC synthetic phenotype; however, much less is known about the role of fibroblast growth factor-2 (FGF2) in this process. Here, we show using signal transduction mutants of FGF receptor 1 (FGFR1) expressed in rat VSMC that the adaptor protein FRS2 is essential for FGFR1-mediated phenotypic modulation and down-regulation of VSMC smooth muscle alpha-actin (SMA) gene expression. In addition, we show that PDGF-BB and FGF2 act synergistically to induce cell proliferation and down-regulate SMA and SM22alpha in VSMC. Furthermore, we show that PDGF-BB induces tyrosine phosphorylation of FGFR1 and that this phosphorylation is mediated by PDGF receptor-beta (PDGFRbeta), but not c-Src. We demonstrate that FRS2 co-immunoprecipitates with PDGFRbeta in a complex that requires FGFR1 and that both the extracellular and the intracellular domains of FGFR1 are required for association with PDGFRbeta, whereas the cytoplasmic domain of FGFR1 is required for FRS2 association with the FGFR1-PDGFRbeta complex. Knockdown of FRS2 in VSMC by RNA interference inhibited PDGF-BB-mediated down-regulation of SMA and SM22alpha without affecting PDGF-BB mediated cell proliferation or ERK activation. Together, these data support the notion that PDGFRbeta down-regulates SMA and SM22alpha through formation of a complex that requires FGFR1 and FRS2 and prove novel insight into VSMC phenotypic plasticity.

FRS2 via fibroblast growth factor receptor 1 is required for platelet-derived growth factor receptor beta-mediated regulation of vascular smooth muscle marker gene expression.

Numerous studies have suggested a link between the angiogenic FGF and VEGF signaling pathways; however, the nature of this link has not been established. To evaluate this relationship, we investigated VEGF signaling in ECs with disrupted FGF signaling in vitro and in vivo. ECs lacking FGF signaling became unresponsive to VEGF, caused by downregulation of VEGF receptor 2 (VEGFR2) expression after reduced Vegfr2 enhancer activation. FGF mediated VEGFR2 expression via activation of Erk1/2. Transcriptional analysis revealed that Ets transcription factors controlled VEGFR2 expression in an FGF- and Erk1/2-dependent manner. Mice with defective FGF signaling exhibited loss of vascular integrity and reduced vascular morphogenesis. Thus, basal FGF stimulation of the endothelium is required for maintenance of VEGFR2 expression and the ability to respond to VEGF stimulation and accounts for the hierarchic control of vascular formation by FGFs and VEGF.

FGF-dependent regulation of VEGF receptor 2 expression in mice.

Mantenimento della normale funzione endoteliale &egrave; fondamentale per vari aspetti della funzione dei vasi sanguigni, ma il regolamento &egrave; capita male. In questo studio, mostriamo che interruzioni di baseline fibroblast growth factor (FGF) segnalazione per l&#39;endotelio porta ad una drammatica riduzione dei livelli di miRNA let-7 che, a sua volta, aumenta l&#39;espressione del transforming growth factor (TGF)-&beta; ligandi e recettori e attivazione del TGF-&beta;, di segnalazione, che conduce alla transizione endoteliali mesenchimali (Endo-MT). Troviamo anche che Endo-MT &egrave; un driver importante della formazione di neointima in un modello di arteriopatia murino trapianto e rigetto dei trapianti umani lesioni. Il declino di FGF endoteliali segnalazione ingresso &egrave; dovuto l&#39;aspetto di uno stato di resistenza di FGF &egrave; caratterizzato da infiammazione-dipendente riduzione nell&#39;espressione e l&#39;attivazione dei componenti chiave di FGF cascata di segnalazione. Questi risultati stabilire FGF segnalando come un fattore critico nel mantenimento dell&#39;omeostasi endoteliale e puntare a un ruolo inatteso di Endo-MT in patologia vascolare.

FGF regola la transizione endotelio mesenchimale e segnalazione di TGF-&beta; tramite controllo di espressione di miRNA let-7.

Maintenance of normal endothelial function is critical to various aspects of blood vessel function, but its regulation is poorly understood. In this study, we show that disruption of baseline fibroblast growth factor (FGF) signaling to the endothelium leads to a dramatic reduction in let-7 miRNA levels that, in turn, increases expression of transforming growth factor (TGF)-Î² ligands and receptors and activation of TGF-Î² signaling, leading to endothelial-to-mesenchymal transition (Endo-MT). We also find that Endo-MT is an important driver of neointima formation in a murine transplant arteriopathy model and in rejection of human transplant lesions. The decline in endothelial FGF signaling input is due to the appearance of an FGF resistance state that is characterized by inflammation-dependent reduction in expression and activation of key components of the FGF signaling cascade. These results establish FGF signaling as a critical factor in maintenance of endothelial homeostasis and point to an unexpected role of Endo-MT in vascular pathology.

FGF regulates TGF-Î² signaling and endothelial-to-mesenchymal transition via control of let-7 miRNA expression.

Entretien de la fonction endoth&eacute;liale normale est critique &agrave; divers aspects de la fonction des vaisseaux sanguins, mais son r&egrave;glement est mal comprise. Dans cette &eacute;tude, nous montrons que perturbation de base fibroblast growth factor (FGF) de signalisation pour l&#39;endoth&eacute;lium m&egrave;ne &agrave; une r&eacute;duction spectaculaire des niveaux de miRNA let-7 qui, &agrave; son tour, augmente l&#39;expression du facteur de croissance (TGF) transformant-&beta; ligands et les r&eacute;cepteurs et activation du TGF-&beta;, signalisation, conduisant &agrave; la transition endoth&eacute;liale &agrave; m&eacute;senchymateuse (Endo-MT). Nous trouvons aussi que Endo-MT est un important moteur de formation n&eacute;o-intimale dans un mod&egrave;le d&#39;art&eacute;riopathie de transplantation murin et rejet des l&eacute;sions de la transplantation humaine. La baisse de FGF endoth&eacute;lial signalisation entr&eacute;e est due &agrave; l&#39;apparition d&#39;un &eacute;tat de r&eacute;sistance de FGF qui se caract&eacute;rise par la r&eacute;duction de l&#39;inflammation-d&eacute;pendante dans l&#39;expression et l&#39;activation des composants cl&eacute;s du FGF cascade de signalisation. Ces r&eacute;sultats &eacute;tablissent FGF signalisation un facteur essentiel dans le maintien de l&#39;hom&eacute;ostasie endoth&eacute;liale et pointent sur un r&ocirc;le inattendu de l&#39;Endo-MT en pathologie vasculaire.

FGF r&eacute;glemente transition signalisation et endoth&eacute;liale &agrave; m&eacute;senchymateuse au TGF-&beta; moyen de contr&ocirc;le de l&#39;expression de la d&eacute;cision no let-7 miRNA.

Vascular endothelial growth factors (VEGFs) signal via their cognate receptor tyrosine kinases designated VEGFR1-3. We report that the docking protein fibroblast growth factor receptor substrate 2 (FRS2α) plays a critical role in cell signaling via these receptors. In vitro FRS2α regulates VEGF-A and VEGF-C-dependent activation of extracellular signal-regulated receptor kinase signaling and blood and lymphatic endothelial cells migration and proliferation. In vivo endothelial-specific deletion of FRS2α results in the profound impairment of postnatal vascular development and adult angiogenesis, lymphangiogenesis, and arteriogenesis. We conclude that FRS2α is a previously unidentified component of VEGF receptors signaling. 

The docking protein FRS2α is a critical regulator of VEGF receptors signaling.

Abnormal vascular homeostasis can lead to increased proliferation of smooth muscle cells and deposition of extracellular matrix, resulting in neointima formation, which contributes to vascular lumen narrowing, a pathology that underlies diseases including transplant vasculopathy, the recurrence of stenosis, and atherosclerosis. Growth of neointima is in part due to endothelial-to-mesenchymal transition (EndMT), a transforming growth factor-β (TGFβ)-driven process, which leads to increased numbers of smooth muscle cells and fibroblasts and deposition of extracellular matrix. We reported that endothelial cell-specific knockout of fibroblast growth factor receptor 1 (FGFR1) led to activation of TGFβ signaling and development of EndMT in vitro and in vivo. Furthermore, EndMT in human diseased vasculature correlated with decreased abundance of FGFR1. These findings identify FGFR1 as the key regulator of TGFβ signaling and EndMT development. 

Fibroblast growth factor receptor 1 is a key inhibitor of TGFβ signaling in the endothelium.

The molecular mechanisms responsible for the development and progression of atherosclerotic lesions have not been fully established. Here, we investigated the role played by endothelial-to-mesenchymal transition (EndMT) and its key regulator FGF receptor 1 (FGFR1) in atherosclerosis. In cultured human endothelial cells, both inflammatory cytokines and oscillatory shear stress reduced endothelial FGFR1 expression and activated TGF-β signaling. We further explored the link between disrupted FGF endothelial signaling and progression of atherosclerosis by introducing endothelial-specific deletion of FGF receptor substrate 2 α (Frs2a) in atherosclerotic (Apoe(-/-)) mice. When placed on a high-fat diet, these double-knockout mice developed atherosclerosis at a much earlier time point compared with that their Apoe(-/-) counterparts, eventually demonstrating an 84% increase in total plaque burden. Moreover, these animals exhibited extensive development of EndMT, deposition of fibronectin, and increased neointima formation. Additionally, we conducted a molecular and morphometric examination of left main coronary arteries from 43 patients with various levels of coronary disease to assess the clinical relevance of these findings. The extent of coronary atherosclerosis in this patient set strongly correlated with loss of endothelial FGFR1 expression, activation of endothelial TGF-β signaling, and the extent of EndMT. These data demonstrate a link between loss of protective endothelial FGFR signaling, development of EndMT, and progression of atherosclerosis.

Endothelial-to-mesenchymal transition drives atherosclerosis progression.

When endothelial cells go rogue.

The conversion of vascular smooth muscle cells (SMCs) from contractile to proliferative phenotype is thought to play an important role in atherosclerosis. However, the contribution of this process to plaque growth has never been fully defined. In this study, we show that activation of SMC TGFβ signaling, achieved by suppression of SMC fibroblast growth factor (FGF) signaling input, induces their conversion to a contractile phenotype and dramatically reduces atherosclerotic plaque size. The FGF/TGFβ signaling cross talk was observed in vitro and in vivo In vitro, inhibition of FGF signaling increased TGFβ activity, thereby promoting smooth muscle differentiation and decreasing proliferation. In vivo, smooth muscle-specific knockout of an FGF receptor adaptor Frs2α led to a profound inhibition of atherosclerotic plaque growth when these animals were crossed on Apoe(-/-) background and subjected to a high-fat diet. In particular, there was a significant reduction in plaque cellularity, increase in fibrous cap area, and decrease in necrotic core size. In agreement with these findings, examination of human coronary arteries with various degrees of atherosclerosis revealed a strong correlation between the activation of FGF signaling, loss of TGFβ activity, and increased disease severity. These results identify SMC FGF/TGFβ signaling cross talk as an important regulator of SMC phenotype switch and document a major contribution of medial SMC proliferation to atherosclerotic plaque growth.

Smooth muscle FGF/TGFβ cross talk regulates atherosclerosis progression.

Smooth muscle cells (SMCs) in normal blood vessels exist in a highly differentiate state characterized by expression of SMC-specific contractile proteins ("contractile phenotype"). Following blood vessel injury in vivo or when cultured in vitro in the presence of multiple growth factors, SMC undergo a phenotype switch characterized by the loss of contractile markers and appearance of expression of non-muscle proteins ("proliferative phenotype"). While a number of factors have been reported to modulate this process, its regulation remains uncertain. Here we show that induction of SMC FGF signaling inhibits TGFβ signaling and converts contractile SMCs to the proliferative phenotype. Conversely, inhibition of SMC FGF signaling induces TGFβ signaling converting proliferating SMCs to the contractile phenotype, even in the presence of various growth factors in vitro or vascular injury in vivo. The importance of this signaling cross-talk is supported by in vivo data that show that an SMC deletion of a pan-FGF receptor adaptor Frs2α (fibroblast growth factor receptor substrate 2 alpha) in mice profoundly reduces neointima formation and vascular remodelling following carotid artery ligation. These results demonstrate that FGF-TGFβ signaling antagonism is the primary regulator of the SMC phenotype switch. Manipulation of this cross-talk may be an effective strategy for treatment of SMC-proliferation related diseases.

Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation.

The development of effective pharmacological treatment of abdominal aortic aneurysm (AAA) potentially offers great benefit to patients with preaneurysmal aortic dilation by slowing the expansion of aneurysms and reducing the need for surgery. To date, therapeutic targets for slowing aortic dilation have had low efficacy. Thus, in this study, we aim to elucidate possible mechanisms driving aneurysm progression to identify potential targets for pharmacological intervention. We demonstrate that mechanistic target of rapamycin (mTOR) signaling is overactivated in aortic smooth muscle cells (SMCs), which contributes to murine AAA. Rapamycin, a typical mTOR pathway inhibitor, dramatically limits the expansion of the abdominal aorta following intraluminal elastase perfusion. Furthermore, reduction of aortic diameter is achieved by inhibition of the mTOR pathway, which preserves and/or restores the contractile phenotype of SMCs and downregulates macrophage infiltration, matrix metalloproteinase expression, and inflammatory cytokine production. Taken together, these results highlight the important role of the mTOR cascade in aneurysm progression and the potential application of rapamycin as a therapeutic candidate for AAA. This study provides novel observations that mechanistic target of rapamycin (mTOR) signaling is overactivated in aortic smooth muscle cells and contributes to mouse abdominal aortic aneurysm (AAA) and that rapamycin protects against aneurysm development. Our data highlight the importance of preservation and/or restoration of the smooth muscle cell contractile phenotype and reduction of inflammation by mTOR inhibition in AAA.

Inhibition of the mTOR pathway in abdominal aortic aneurysm: implications of smooth muscle cell contractile phenotype, inflammation, and aneurysm expansion.

Despite much effort, atherosclerosis remains an important public health problem, leading to substantial morbidity and mortality worldwide. The purpose of this review is to provide an understanding of the role of endothelial cell fate change in atherosclerosis process.

Fibroblast growth factor-transforming growth factor beta dialogues, endothelial cell to mesenchymal transition, and atherosclerosis.

Resilience, disease and the age of single cell science.

The etiology of aortic aneurysms is poorly understood, but it is associated with atherosclerosis, hypercholesterolemia, and abnormal transforming growth factor β (TGF-β) signaling in smooth muscle. Here, we investigated the interactions between these different factors in aortic aneurysm development and identified a key role for smooth muscle cell (SMC) reprogramming into a mesenchymal stem cell (MSC)-like state. SMC-specific ablation of TGF-β signaling in Apoe mice on a hypercholesterolemic diet led to development of aortic aneurysms exhibiting all the features of human disease, which was associated with transdifferentiation of a subset of contractile SMCs into an MSC-like intermediate state that generated osteoblasts, chondrocytes, adipocytes, and macrophages. This combination of medial SMC loss with marked increases in non-SMC aortic cell mass induced exuberant growth and dilation of the aorta, calcification and ossification of the aortic wall, and inflammation, resulting in aneurysm development.

Smooth Muscle Cell Reprogramming in Aortic Aneurysms.

Atherosclerosis is a chronic progressive disease characterized by vascular inflammation and growth of atherosclerotic plaque that eventually lead to compromise of blood flow. The disease has proven to be remarkably resistant to multiple attempts at meaningful reversal including recent strategies targeting selective inflammatory mediators. Endothelial-to-mesenchymal transition (EndMT) has emerged as a key driver of both vascular inflammation and plaque growth. A deeper understanding of EndMT provides new insights into the underlying biology of atherosclerosis, suggests likely molecular mechanism of atherosclerotic resistance, and identifies potential new therapeutic targets.

ArticleTotal : 3	Year
Publication title Cited by 42	2018
Publication title Cited by 7	2022
Publication title Cited by 1	2022

Article	Year
Endothelial TGF-β signalling drives vascular inflammation and atherosclerosis. Nature metabolism\| PubMed ID: 31572976	2019
FRS2 via fibroblast growth factor receptor 1 is required for platelet-derived growth factor receptor beta-mediated regulation of vascular smooth muscle marker gene expression. The Journal of biological chemistry\| PubMed ID: 19339244	2009
FGF-dependent regulation of VEGF receptor 2 expression in mice. The Journal of clinical investigation\| PubMed ID: 21633168	2011
FGF regulates TGF-Î² signaling and endothelial-to-mesenchymal transition via control of let-7 miRNA expression. Cell reports\| PubMed ID: 23200853	2012
The docking protein FRS2α is a critical regulator of VEGF receptors signaling. Proceedings of the National Academy of Sciences of the United States of America\| PubMed ID: 24706887	2014
Fibroblast growth factor receptor 1 is a key inhibitor of TGFβ signaling in the endothelium. Science signaling\| PubMed ID: 25249657	2014
Endothelial-to-mesenchymal transition drives atherosclerosis progression. The Journal of clinical investigation\| PubMed ID: 26517696	2015
When endothelial cells go rogue. EMBO molecular medicine\| PubMed ID: 26613939	2016
Smooth muscle FGF/TGFβ cross talk regulates atherosclerosis progression. EMBO molecular medicine\| PubMed ID: 27189169	2016
Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation. Scientific reports\| PubMed ID: 27634335	2016
Inhibition of the mTOR pathway in abdominal aortic aneurysm: implications of smooth muscle cell contractile phenotype, inflammation, and aneurysm expansion. American journal of physiology. Heart and circulatory physiology\| PubMed ID: 28213405	2017
Fibroblast growth factor-transforming growth factor beta dialogues, endothelial cell to mesenchymal transition, and atherosclerosis. Current opinion in lipidology\| PubMed ID: 30080704	2018
Resilience, disease and the age of single cell science. Aging\| PubMed ID: 32039835	2020
Smooth Muscle Cell Reprogramming in Aortic Aneurysms. Cell stem cell\| PubMed ID: 32243809	2020
Endothelial-to-Mesenchymal Transition, Vascular Inflammation, and Atherosclerosis. Frontiers in cardiovascular medicine\| PubMed ID: 32478094	2020

Pei-Yu Chen

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