A biomimetic platelet based on assembling peptides initiates artificial coagulation

Platelets play a critical role in the regulation of coagulation, one of the essential processes in life, attracting great attention. However, mimicking platelets for in vivo artificial coagulation is still a great challenge due to the complexity of the process. Here, we design platelet-like nanoparticles (pNPs) based on self-assembled peptides that initiate coagulation and form clots in blood vessels. The pNPs first bind specifically to a membrane glycoprotein (i.e., CD105) overexpressed on angiogenetic endothelial cells in the tumor site and simultaneously transform into activated platelet-like nanofibers (apNFs) through ligand-receptor interactions. Next, the apNFs expose more binding sites and recruit and activate additional pNPs, forming artificial clots in both phantom and animal models. The pNPs are proven to be safe in mice without systemic coagulation. The self-assembling peptides mimic platelets and achieve artificial coagulation in vivo, thus providing a promising therapeutic strategy for tumors.

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Prrx1 promotes stemness and angiogenesis via activating TGF-β/smad pathway and upregulating proangiogenic factors in glioma

Cell Death and Disease ◽

10.1038/s41419-021-03882-7 ◽

2021 ◽

Vol 12 (6) ◽

Author(s):

Zetao Chen ◽

Yihong Chen ◽

Yan Li ◽

Weidong Lian ◽

Kehong Zheng ◽

...

Keyword(s):

Stem Cells ◽

Therapeutic Strategy ◽

Critical Role ◽

Glioma Stem Cells ◽

Promoter Regions ◽

Aberrant Expression ◽

Smad Pathway ◽

Tgf Β1

AbstractGlioma is one of the most lethal cancers with highly vascularized networks and growing evidences have identified glioma stem cells (GSCs) to account for excessive angiogenesis in glioma. Aberrant expression of paired-related homeobox1 (Prrx1) has been functionally associated with cancer stem cells including GSCs. In this study, Prrx1 was found to be markedly upregulated in glioma specimens and elevated Prrx1 expression was inversely correlated with prognosis of glioma patients. Prrx1 potentiated stemness acquisition in non-stem tumor cells (NSTCs) and stemness maintenance in GSCs, accompanied with increased expression of stemness markers such as SOX2. Prrx1 also promoted glioma angiogenesis by upregulating proangiogenic factors such as VEGF. Consistently, silencing Prrx1 markedly inhibited glioma proliferation, stemness, and angiogenesis in vivo. Using a combination of subcellular proteomics and in vitro analyses, we revealed that Prrx1 directly bound to the promoter regions of TGF-β1 gene, upregulated TGF-β1 expression, and ultimately activated the TGF-β/smad pathway. Silencing TGF-β1 mitigated the malignant behaviors induced by Prrx1. Activation of this pathway cooperates with Prrx1 to upregulate the expression of stemness-related genes and proangiogenic factors. In summary, our findings revealed that Prrx1/TGF-β/smad signal axis exerted a critical role in glioma stemness and angiogeneis. Disrupting the function of this signal axis might represent a new therapeutic strategy in glioma patients.

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Dual oxidase 1 limits the IFNγ-associated antitumor effect of macrophages

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-000622 ◽

2020 ◽

Vol 8 (1) ◽

pp. e000622

Author(s):

Lydia Meziani ◽

Marine Gerbé de Thoré ◽

Pauline Hamon ◽

Sophie Bockel ◽

Ruy Andrade Louzada ◽

...

Keyword(s):

Antitumor Effect ◽

Therapeutic Strategy ◽

Critical Role ◽

Tumor Development ◽

Intratumoral Injection ◽

Histocompatibility Complex ◽

Dual Oxidase

BackgroundMacrophages play pivotal roles in tumor progression and the response to anticancer therapies, including radiotherapy (RT). Dual oxidase (DUOX) 1 is a transmembrane enzyme that plays a critical role in oxidant generation.MethodsSince we found DUOX1 expression in macrophages from human lung samples exposed to ionizing radiation, we aimed to assess the involvement of DUOX1 in macrophage activation and the role of these macrophages in tumor development.ResultsUsing Duox1−/− mice, we demonstrated that the lack of DUOX1 in proinflammatory macrophages improved the antitumor effect of these cells. Furthermore, intratumoral injection of Duox1−/− proinflammatory macrophages significantly enhanced the antitumor effect of RT. Mechanistically, DUOX1 deficiency increased the production of proinflammatory cytokines (IFNγ, CXCL9, CCL3 and TNFα) by activated macrophages in vitro and the expression of major histocompatibility complex class II in the membranes of macrophages. We also demonstrated that DUOX1 was involved in the phagocytotic function of macrophages in vitro and in vivo. The antitumor effect of Duox1−/− macrophages was associated with a significant increase in IFNγ production by both lymphoid and myeloid immune cells.ConclusionsOur data indicate that DUOX1 is a new target for macrophage reprogramming and suggest that DUOX1 inhibition in macrophages combined with RT is a new therapeutic strategy for the management of cancers.

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My D88-Dependent Interplay Between Myeloid and Endothelial Cells in the Initiation and Progression of Obesity-Associated Inflammatory Diseases

Blood ◽

10.1182/blood.v128.22.sci-44.sci-44 ◽

2016 ◽

Vol 128 (22) ◽

pp. SCI-44-SCI-44

Author(s):

Xiaoxia Li

Keyword(s):

Insulin Resistance ◽

Endothelial Cells ◽

Adipose Tissue ◽

Systemic Inflammation ◽

Conflicts Of Interest ◽

Ex Vivo ◽

Inflammatory Diseases ◽

Critical Role ◽

Low Grade

Abstract Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases. Disclosures No relevant conflicts of interest to declare.

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Disruption of endothelial Pfkfb3 ameliorates diet-induced murine insulin resistance

Journal of Endocrinology ◽

10.1530/joe-20-0524 ◽

2021 ◽

Author(s):

Qiuhua Yang ◽

Jiean Xu ◽

Qian Ma ◽

Zhiping Liu ◽

Yaqi Zhou ◽

...

Keyword(s):

Insulin Resistance ◽

Endothelial Cells ◽

High Fat Diet ◽

Inflammatory Responses ◽

Critical Role ◽

Endothelial Inflammation ◽

Glucose Clearance ◽

Deficient Mice

Overnutrition-induced endothelial inflammation plays a crucial role in high fat diet (HFD)-induced insulin resistance in animals. Endothelial glycolysis plays a critical role in endothelial inflammation and proliferation, but its role in diet-induced endothelial inflammation and subsequent insulin resistance has not been elucidated. PFKFB3 is a critical glycolytic regulator, and its increased expression has been observed in adipose vascular endothelium of C57BL/6J mice fed with HFD in vivo, and in palmitate (PA)-treated primary human adipose microvascular endothelial cells (HAMECs) in vitro. We generated mice with Pfkfb3 deficiency selective for endothelial cells to examine the effect of endothelial Pfkfb3 in endothelial inflammation in metabolic organs and in the development of HFD-induced insulin resistance. EC Pfkfb3-deficient mice exhibited mitigated HFD-induced insulin resistance, including decreased body weight and fat mass, improved glucose clearance and insulin sensitivity, and alleviated adiposity and hepatic steatosis. Mechanistically, cultured PFKFB3 knockdown HAMECs showed decreased NF-κB activation induced by PA, and consequent suppressed adhesion molecule expression and monocyte adhesion. Taken together, these results demonstrate that increased endothelial PFKFB3 expression promotes diet-induced inflammatory responses and subsequent insulin resistance, suggesting that endothelial metabolic alteration plays an important role in the development of insulin resistance.

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Functional neurokinin 1 receptors for substance P are expressed by human vascular endothelium.

Journal of Experimental Medicine ◽

10.1084/jem.177.5.1269 ◽

1993 ◽

Vol 177 (5) ◽

pp. 1269-1276 ◽

Cited By ~ 51

Author(s):

E W Greeno ◽

P Mantyh ◽

G M Vercellotti ◽

C F Moldow

Keyword(s):

Endothelial Cells ◽

Substance P ◽

Binding Sites ◽

Critical Role ◽

Calcium Flux ◽

Human Umbilical Cord ◽

Aortic Endothelial Cells ◽

Neurokinin 1 ◽

Human Endothelium

Substance P (SP), a neurotachykinin, is important in a number of inflammatory processes in which the endothelial cell also plays a critical role. SP receptors have previously been identified only on arterial endothelium, and the scant in vitro evidence for direct effects of SP on human endothelium is based on studies using nonarterial cells. To better understand SP's role in inflammation, we sought to identify functional SP receptors on human endothelium in situ and in culture. Autoradiographic ligand binding to human umbilical cord sections demonstrates the presence of SP binding sites with characteristics of the neurokinin 1 (NK-1) receptor (displacement by GTP analogues and the NK-1 specific antagonist CP-96,345) on human umbilical arterial, but not venous, endothelium. In culture, human umbilical venous endothelial cells (HUVECs) and human aortic endothelial cells express low levels of available SP binding sites. However, HUVECs, which are serum starved and refed, undergo a dramatic increase in SP binding. SP binding to starved/refed HUVECs induces a transient increase in intracellular calcium. This calcium flux is dose dependent over appropriate SP concentrations and can be blocked by NK-1 specific antagonists. The proinflammatory effects of SP may be mediated in part through the NK-1 receptor on endothelium.

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Impaired angiogenesis and altered Notch signaling in mice overexpressing endothelial Egfl7

Blood ◽

10.1182/blood-2010-03-274860 ◽

2010 ◽

Vol 116 (26) ◽

pp. 6133-6143 ◽

Cited By ~ 71

Author(s):

Donna Nichol ◽

Carrie Shawber ◽

Michael J. Fitch ◽

Kathryn Bambino ◽

Anshula Sharma ◽

...

Keyword(s):

Endothelial Cells ◽

Notch Signaling ◽

Target Genes ◽

Critical Role ◽

Endothelial Cell Proliferation ◽

Vascular Patterning ◽

Cardiac Morphogenesis ◽

Epidermal Growth ◽

And Migration

Abstract Epidermal growth factor-like domain 7 (Egfl7) is important for regulating tubulogenesis in zebrafish, but its role in mammals remains unresolved. We show here that endothelial overexpression of Egfl7 in transgenic mice leads to partial lethality, hemorrhaging, and altered cardiac morphogenesis. These defects are accompanied by abnormal vascular patterning and remodeling in both the embryonic and postnatal vasculature. Egfl7 overexpression in the neonatal retina results in a hyperangiogenic response, and EGFL7 knockdown in human primary endothelial cells suppresses endothelial cell proliferation, sprouting, and migration. These phenotypes are reminiscent of Notch inhibition. In addition, our results show that EGFL7 and endothelial-specific NOTCH physically interact in vivo and strongly suggest that Egfl7 antagonizes Notch in both the postnatal retina and in primary endothelial cells. Specifically, Egfl7 inhibits Notch reporter activity and down-regulates the level of Notch target genes when overexpressed. In conclusion, we have uncovered a critical role for Egfl7 in vascular development and have shown that some of these functions are mediated through modulation of Notch signaling.

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The Mechanism and Feasibility of Self-Assembly with Capillary Force

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.339.234 ◽

2007 ◽

Vol 339 ◽

pp. 234-239 ◽

Cited By ~ 1

Author(s):

D.P. Zhao ◽

D. Wu ◽

K. Chen

Keyword(s):

Self Assembly ◽

Binding Sites ◽

Capillary Force ◽

Capillary Forces ◽

Interfacial Free Energy ◽

The Self ◽

Material System ◽

Self Assembling ◽

Hydrophilic Material ◽

Micro Parts

This paper introduces a fluidic technique based on patterned shapes of hydrophobic self-assembly monolayers (SAMs) and capillary forces to self-assemble micro-parts onto substrates. Self-assembly is defined as a spontaneous process that occurs in a statistical, non-guided fashion. More specifically, the fluidic self-assembly with capillary force is driven by the gradient in interfacial free energy when a micro-part approaches a substrate binding site. In this paper, the mechanism of self-assembly with capillary forces is proposed. The hydrophobic-hydrophilic material system between the binding sites and micro-parts is then simulated. Finally, the surface energy of a self-assembling system in the liquid phase under different conditions is calculated. The results show that shift, twist, lift and tilts displacements are detected to be rather uncritical and the system turns out to be rather stiff with respect to such displacements. The theoretical result is supported by the experiments and gives quantitive explanations why and how the capillary force works in the self-assembly process.

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Endothelial cells respond to hyperglycemia by increasing the LPL transporter GPIHBP1

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00007.2014 ◽

2014 ◽

Vol 306 (11) ◽

pp. E1274-E1283 ◽

Cited By ~ 12

Author(s):

Amy Pei-Ling Chiu ◽

Fulong Wang ◽

Nathaniel Lal ◽

Ying Wang ◽

Dahai Zhang ◽

...

Keyword(s):

Endothelial Cells ◽

Protein Expression ◽

Binding Sites ◽

Therapeutic Strategy ◽

Density Lipoprotein ◽

Streptozotocin Diabetes ◽

Gene And Protein Expression ◽

Lipoprotein Binding ◽

Rate Limiting

In diabetes, when glucose uptake and oxidation are impaired, the heart is compelled to use fatty acid (FA) almost exclusively for ATP. The vascular content of lipoprotein lipase (LPL), the rate-limiting enzyme that determines circulating triglyceride clearance, is largely responsible for this FA delivery and increases following diabetes. Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein [GPIHBP1; a protein expressed abundantly in the heart in endothelial cells (EC)] collects LPL from the interstitial space and transfers it across ECs onto the luminal binding sites of these cells, where the enzyme is functional. We tested whether ECs respond to hyperglycemia by increasing GPIHBP1. Streptozotocin diabetes increased cardiac LPL activity and GPIHBP1 gene and protein expression. The increased LPL and GPIHBP1 were located at the capillary lumen. In vitro, passaging EC caused a loss of GPIHBP1, which could be induced on exposure to increasing concentrations of glucose. The high-glucose-induced GPIHBP1 increased LPL shuttling across EC monolayers. GPIHBP1 expression was linked to the EC content of heparanase. Moreover, active heparanase increased GPIHBP1 gene and protein expression. Both ECs and myocyte heparan sulfate proteoglycan-bound platelet-derived growth factor (PDGF) released by heparanase caused augmentation of GPIHBP1. Overall, our data suggest that this protein “ensemble” (heparanase-PDGF-GPIHBP1) cooperates in the diabetic heart to regulate FA delivery and utilization by the cardiomyocytes. Interrupting this axis may be a novel therapeutic strategy to restore metabolic equilibrium, curb lipotoxicity, and help prevent or delay heart dysfunction that is characteristic of diabetes.

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PPARs and angiogenesis

Biochemical Society Transactions ◽

10.1042/bst20110643 ◽

2011 ◽

Vol 39 (6) ◽

pp. 1601-1605 ◽

Cited By ~ 51

Author(s):

David Bishop-Bailey

Keyword(s):

Endothelial Cells ◽

Critical Role ◽

Molecular Target ◽

Experimental Models ◽

Peroxisome Proliferator ◽

Peroxisome Proliferator Activated Receptor ◽

Angiogenic Switch ◽

Receptor Family

The PPAR (peroxisome-proliferator-activated receptor) family consists of three ligand-activated nuclear receptors: PPARα, PPARβ/δ and PPARγ. These PPARs have important roles in the regulation of glucose and fatty acid metabolism, cell differentiation and immune function, but were also found to be expressed in endothelial cells in the late 1990s. The early endothelial focus of PPARs was PPARγ, the molecular target for the insulin-sensitizing thiazolidinedione/glitazone class of drugs. Activation of PPARγ was shown to inhibit angiogenesis in vitro and in models of retinopathy and cancer, whereas more recent data point to a critical role in the development of the vasculature in the placenta. Similarly, PPARα, the molecular target for the fibrate class of drugs, also has anti-angiogenic properties in experimental models. In contrast, unlike PPARα or PPARγ, activation of PPARβ/δ induces angiogenesis, in vitro and in vivo, and has been suggested to be a critical component of the angiogenic switch in pancreatic cancer. Moreover, PPARβ/δ is an exercise mimetic and appears to contribute to the angiogenic remodelling of cardiac and skeletal muscle induced by exercise. This evidence and the emerging mechanisms by which PPARs act in endothelial cells are discussed in more detail.

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Abstract 3662: Involvement Of The Small Gtpase Rap1 In Integrin Signaling In Endothelial Cells And Postnatal Neovascularization

Circulation ◽

10.1161/circ.118.suppl_18.s_461-a ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Guillaume Carmona ◽

Alessia Orlandi ◽

Henschler Reinhard ◽

Andreas. M Zeiher ◽

Stefanie Dimmeler ◽

...

Keyword(s):

Endothelial Cells ◽

Microvessel Density ◽

Umbilical Vein ◽

Critical Role ◽

Significant Inhibition ◽

Small Gtpase ◽

Integrin Signaling ◽

Wild Type

Ras associated protein 1 (Rap1), a small GTPase of the Ras family, has attracted much attention because of its involvement in several aspects of cell adhesion, including integrin- and cadherin-mediated adhesion. Yet, the role of Rap1 genes for integrin signaling in endothelial cells (EC) and angiogenesis has not been investigated. Human umbilical vein endothelial cells (HUVEC) express Rap1a and Rap1b mRNA as assessed by RT-PCR. In order to determine the contribution of Rap1 activity for angiogenesis, we overexpressed Rap1GAP1, a GTPase activating protein, which specifically inhibits the activity of both Rap1a and Rap1b. Overexpression of Rap1GAP1 led to a significant inhibition of angiogenic sprouting of HUVEC under basal conditions and bFGF stimulation by 44 ± 5 % in a 3-dimensional spheroidal system and blocked tube formation in a matrigel assay, migration and adhesion. In order to separately investigate the role of Rap1a and Rap1b genes in angiogenesis, we performed gene silencing with siRNA. Silencing of either Rap1a or Rap1b significantly and additively blocked the sprouting of HUVEC under basal and bFGF-stimulated conditions (Rap1a-siRNA: 55 ± 5 %, Rap1b-siRNA: 61 ± 9 % and Rap1a+Rap1b siRNA: 73 ± 5% inhibition) and significantly reduced HUVEC migration and adhesion on fibronectin and collagen. Moreover, silencing of Rap1a and Rap1b reduced beta1-integrin affinity in HUVEC, suggesting the importance of Rap1a and Rap1b for inside-out integrin activation in EC. In addition, silencing of Rap1a and Rap1b prevented VEGF-induced PKB/Akt1 activation. These data prompted us to investigate the in vivo role of Rap1a using Rap1a-deficient mice. Interestingly, Rap1a −/− mice are born with a substantially reduced mendelian ratio. Rap1a +/− heterozygote mice displayed decreased microvessel density in comparison to wild-type mice (Rap1a +/+ ) in a matrigel plug assay. Moreover Rap1a +/− and Rap1a −/− displayed significantly reduced microvessel density in ischemic muscles in the model of hind limb ischemia in comparison to wild-type mice (Rap1a +/− : 32 ± 3 % ; Rap1a −/− : 43 ± 3 % inhibition). Thus, our data demonstrated a critical role of Rap1 in the regulation of β1-integrin signaling in endothelial cells and for postnatal neovascularization.

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