Pathway In Vascular Endothelial Cells Research Articles

Unlocking the secrets of NPSLE: the role of dendritic cell-secreted CCL2 in blood-brain barrier disruption.

This study employed RNA-seq technology and meta-analysis to unveil the molecular mechanisms of neuropsychiatric systemic lupus erythematosus (NPSLE) within the central nervous system. Downloaded transcriptomic data on systemic lupus erythematosus (SLE) from the Gene Expression Omnibus (GEO) and analyzed differential genes in peripheral blood samples of NPSLE patients and healthy individuals. Employed WGCNA to identify key genes related to cognitive impairment and validated findings via RNA-seq. Conducted GO, KEGG, and GSEA analyses, and integrated PPI networks to explore gene regulatory mechanisms. Assessed gene impacts on dendritic cells and blood-brain barrier using RT-qPCR, ELISA, and in vitro models. Public databases and RNA-seq data have revealed a significant upregulation of CCL2 (C-C motif chemokine ligand 2) in the peripheral blood of both SLE and NPSLE patients, primarily secreted by mature dendritic cells. Furthermore, the secretion of CCL2 by mature dendritic cells may act through the RSAD2-ISG15 axis and is associated with the activation of the NLRs (Nod Like Receptor Signaling Pathway) signaling pathway in vascular endothelial cells. Subsequent in vitro cell experiments confirmed the high expression of CCL2 in peripheral blood dendritic cells of NPSLE patients, with its secretion being regulated by the RSAD2-ISG15 axis and inducing vascular endothelial cell pyroptosis through the activation of the NLRs signaling pathway. Clinical trial results ultimately confirmed that NPSLE patients exhibiting elevated CCL2 expression also experienced cognitive decline. The secretion of CCL2 by dendritic cells induces pyroptosis in vascular endothelial cells, thereby promoting blood-brain barrier damage and triggering cognitive impairment in patients with systemic lupus erythematosus.

Uptake Pathway of Styrene Maleic Acid Copolymer-Coated Lipid Emulsions Under Acidic Tumor Microenvironment

The purpose of this study was to elucidate and compare styrene maleic acid copolymer (SMA)-coated lipid emulsions (SMA emulsions) uptake pathway in vascular endothelial cells and surrounding cancer cells under not only neutral but also acidic pH, which is often observed in tumor microenvironment. DiI-labeled SMA emulsions were prepared using 1-palmitoyl-2-oleoyl-sn‑glycero-3-phosphocholine and triolein. In murine melanoma B16-BL6 (B16) cells and human umbilical vein endothelial cells (HUVEC), DiI-labeled SMA emulsions uptake under near-neutral (pH 7.4) and acidic (pH 6.0) conditions was determined by fluorescent analysis. SMA emulsions were taken up more efficiently into HUVEC than B16 cells under acidic condition in a temperature-dependent manner. Uptake study using endocytosis inhibitors showed that SMA emulsions were taken up by macropinocytosis and clathrin-mediated endocytosis in B16 cells. In HUVEC, however, they were taken up by clathrin- and caveolae-independent, but dynamin-dependent pathway. SMA emulsions would be internalized efficiently into vascular endothelial cells as well as cancer cells under acidic microenvironment via different endocytosis pathways. SMA emulsions could be a promising drug delivery carrier for anti-angiogenic drugs.

Esculentoside A ameliorates BSCB destruction in SCI rat by attenuating the TLR4 pathway in vascular endothelial cells

Background and aimsOverexpressed MMP-9 in vascular endothelial cells is involved in blood spinal cord barrier (BSCB) dysfunction in spinal cord injury (SCI). Esculentoside A (EsA) has anti-inflammatory and cell protective effects. This study aimed to evaluate its effects on neuromotor function in SCI rats, as well as the potential mechanisms. MethodsThe therapeutic effect of EsA in SCI rats was investigated using Basso-Beattie-Bresnahan (BBB) scores, a grid walk test and histological analyses. To assess the protective role of EsA in the BSCB and in oxygen glucose deprivation/reoxygenation (OGD/R)-induced hBMECs, the BSCB function, tight junctions (TJ) protein (ZO-1 and claudin-5) expression, structure of the BSCB and Matrix metalloproteinase-9 (MMP-9) expression were observed via Evans blue (EB) detection, immunofluorescence analyses and western blotting. Molecular docking simulations and additional experiments were performed to explore the potential mechanisms by which EsA maintains the function of the BSCB in vivo and in vitro. ResultsEsA treatment improved BBB scores, reduced cavity formation and the loss of neuronal cells, demonstrating an improvement in motor function in SCI rats. In vivo experiments showed that EsA decreased the infiltration of blood cells and inflammatory mediators (IL-1β, IL-6 and TNF-α) and protected the structure of TJs in the rat spinal cord and in OGD/R-induced hBMECs. EsA inhibited the activation of Toll-like receptor 4 (TLR4) signalling, which may be related to the protective effect of EsA against MMP-9-induced BSCB damage. ConclusionsEsA downregulated MMP-9 expression in vascular endothelial cells, protected BSCB function in SCI rats and attenuated TLR4 signalling and thus provide new options for the treatment of SCI.

Identification and validation of G protein-coupled receptors modulating flow-dependent signaling pathways in vascular endothelial cells

Vascular endothelial cells are exposed to mechanical forces due to their presence at the interface between the vessel wall and flowing blood. The patterns of these mechanical forces (laminar vs. turbulent) regulate endothelial cell function and play an important role in determining endothelial phenotype and ultimately cardiovascular health. One of the key transcriptional mediators of the positive effects of laminar flow patterns on endothelial cell phenotype is the zinc-finger transcription factor, krüppel-like factor 2 (KLF2). Given its importance in maintaining a healthy endothelium, we sought to identify endothelial regulators of the KLF2 transcriptional program as potential new therapeutic approaches to treating cardiovascular disease. Using an approach that utilized both bioinformatics and targeted gene knockdown, we identified endothelial GPCRs capable of modulating KLF2 expression. Genetic screening using siRNAs directed to these GPCRs identified 12 potential GPCR targets that could modulate the KLF2 program, including a subset capable of regulating flow-induced KLF2 expression in primary endothelial cells. Among these targets, we describe the ability of several GPCRs (GPR116, SSTR3, GPR101, LGR4) to affect KLF2 transcriptional activation. We also identify these targets as potential validated targets for the development of novel treatments targeting the endothelium. Finally, we highlight the initiation of drug discovery efforts for LGR4 and report the identification of the first known synthetic ligands to this receptor as a proof-of-concept for pathway-directed phenotypic screening to identify novel drug targets.

Retraction Note: Calycosin-7-O-β-D-glucoside promotes oxidative stress-induced cytoskeleton reorganization through integrin-linked kinase signaling pathway in vascular endothelial cells

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12906-015-0839-5.

Angiogenic adipokine C1q-TNF-related protein 9 ameliorates myocardial infarction via histone deacetylase 7-mediated MEF2 activation.

C1q/tumor necrosis factor-related protein 9 (CTRP9) is an adipokine and has high potential as a therapeutic target. However, the role of CTRP9 in cardiovascular disease pathogenesis remains unclear. We found CTRP9 to induce HDAC7 and p38 MAPK phosphorylation via tight regulation of AMPK in vascular endothelial cells, leading to angiogenesis through increased MEF2 activity. The expression of CTRP9 and atheroprotective MEF2 was decreased in plaque tissue of atherosclerotic patients and the ventricle of post-infarction mice. CTRP9 treatment inhibited the formation of atherosclerotic plaques in ApoE KO and CTRP9 KO mice. In addition, CTRP9 induced significant ischemic injury prevention in the post-MI mice. Clinically, serum CTRP9 levels were reduced in patients with MI compared with healthy controls. In summary, CTRP9 induces a vasoprotective response via the AMPK/HDAC7/p38 MAPK pathway in vascular endothelial cells, whereas its absence can contribute to atherosclerosis and MI. Hence, CTRP9 may represent a valuable therapeutic target and biomarker in cardiovascular diseases.

HIF-1α promotes the expression of syndecan-1 and inhibits the NLRP3 inflammasome pathway in vascular endothelial cells under hemorrhagic shock

Hemorrhagic shock (HS) is a global life-threatening matter that causes massive mortality annually worldwide. Syndecan-1 (SDC1) is an important predictor and evaluation index for HS, but its mechanism involved in the HS development remain unclear. HS mice model and human umbilical vein endothelial cells (HUVECs) under hypoxia were applied to explore the relationship of SDC1 with HIF-1α and NLRP3 inflammasome in vascular ECs under HS. Transcriptome sequencing of isolated vascular ECs were conduct to search for hub genes. Dual luciferase assay was adopted to prove the binding effects of the HIF-1α on SDC1 promoter in HUVECs. Molecular expression was evaluated through routine experiments. Here, HS led to aggravated lung injury and inflammatory response with the shedding of SDC1 on the lung vascular ECs in mice. Circulatory SDC1 and proinflammatory cytokines were significantly increased after HS. HIF-1α and IL-1β were identified as hub genes in vascular ECs of HS mice. Meanwhile, HIF-1α-mediaed hypoxia and IL-1β-involved NLRP3 inflammasome pathways were activated following HS. The transcriptional factor HIF-1α promoted the expression of SDC1 through binding to the SDC1 promoter. SDC1 had an inhibitory effect on the NLRP3 inflammasome activity. An exogenous increase of HIF-1α upregulated SDC1 and restrained the activation of the NLRP3 inflammasome under hypoxia, while further interference of SDC1 weakened this effect. Hence, SDC1 is an intermediate connecting HIF-1α and NLRP3 inflammasome in the vascular ECs under hypoxia. HIF-1α promotes the expression of SDC1 and inhibits the NLRP3 inflammasome pathway in vascular ECs under HS.

Reciprocal regulation of NRF2 by autophagy and ubiquitin–proteasome modulates vascular endothelial injury induced by copper oxide nanoparticles

NRF2 is the key antioxidant molecule to maintain redox homeostasis, however the intrinsic mechanisms of NRF2 activation in the context of nanoparticles (NPs) exposure remain unclear. In this study, we revealed that copper oxide NPs (CuONPs) exposure activated NRF2 pathway in vascular endothelial cells. NRF2 knockout remarkably aggravated oxidative stress, which were remarkably mitigated by ROS scavenger. We also demonstrated that KEAP1 (the negative regulator of NRF2) was not primarily involved in NRF2 activation in that KEAP1 knockdown did not significantly affect CuONPs-induced NRF2 activation. Notably, we demonstrated that autophagy promoted NRF2 activation as evidenced by that ATG5 knockout or autophagy inhibitors significantly blocked NRF2 pathway. Mechanically, CuONPs disturbed ubiquitin–proteasome pathway and consequently inhibited the proteasome-dependent degradation of NRF2. However, autophagy deficiency reciprocally promoted proteasome activity, leading to the acceleration of degradation of NRF2 via ubiquitin–proteasome pathway. In addition, the notion that the reciprocal regulation of NRF2 by autophagy and ubiquitin–proteasome was further proven in a CuONPs pulmonary exposure mice model. Together, this study uncovers a novel regulatory mechanism of NRF2 activation by protein degradation machineries in response to CuONPs exposure, which opens a novel intriguing scenario to uncover therapeutic strategies against NPs-induced vascular injury and disease.Graphical

Network-Based Analysis Reveals Gene Signature in Tip Cells and Stalk Cells.

Angiogenesis occurs during various physiological or pathological processes such as wound healing and tumor growth. Differentiation of vascular endothelial cells into tip cells and stalk cells initiates the formation of new blood vessels. Tip cells and stalk cells are endothelial cells with different biological characteristics and functions. The aim of this study was to determine the mechanisms of angiogenesis by exploring differences in gene expression of tip cells and stalk cells. Raw data were retrieved from NCBI Gene Expression Omnibus (GSE19284). Data were reanalyzed using bioinformatics methods that employ robust statistical methods, including identification of differentially expressed genes (DEGs) between the stalk and tip cells, Weighted Gene Correlation Network Analysis (WGCNA), gene ontology and pathway enrichment analysis using DAVID tools, integration of Protein-Protein Interaction (PPI) networks and screening of hub genes. DEGs of stalk and tip cells were grouped as dataset A. Gene modules associated with differentiation of stalk and tip cells screened by WGCNA were named dataset B. Further, we retrieved existing markers of angiogenesis from previous experimental studies on tip and stalk cells which we called dataset C. Intersection of datasets A, B and C was used as a candidate gene. Subsequently, we verified the results applying Quantitative Polymerase Chain Reaction (Q-PCR) to our clinical specimen. In general, the Q-PCR results coincide with the majority of the expression profile. We identified five candidate genes, including ESM1, CXCR4, JAG1, FLT1 and PTK2, and two pathways, including Rap1 signaling pathway and PI3K-Akt signaling pathway in vascular endothelial cells that differentiate into tip cells and stalk cells using bioinformatics analysis. Bioinformatics approaches provide new avenues for basic research in different fields such as angiogenesis. The findings of this study provide new perspectives and a basis for the study of molecular mechanisms of vascular endothelial cell differentiation into stalk and tip cells. Genes and pathways identified in this study are potential biomarkers and therapeutic targets for angiogenesis in the tumor.

Dopamine 1 receptors inhibit apoptosis via activating CSE/H2 S pathway in high glucose-induced vascular endothelial cells.

High glucose (HG)-induced dysfunction of vascular endothelial cells plays a crucial role in the development of diabetic vascular complications. Inhibition of cystathionine γ-synthase/hydrogen sulfide (CSE/H2 S) pathway is one of the causes of vascular endothelial cellinjury induced by HG. Dopamine D1 receptors (DR1) are widely expressed and regulate important physiological functions in the vascular system. However, the effect of DR1 inhibition on HG-induced vascular endothelial apoptosis by regulating the CSE/H2 S pathway is unclear. Therefore, we aimed to determine if DR1 can regulate the CSE/H2 S pathway and regulate the effect of DR1 on HG-induced apoptosis in human umbilical vein endothelial cells. In this study, we found that HG treatment significantly decreased the expression of DR1 and CSE and the endogenous content of H2 S;DR1 agonist SKF 38393 reversed these effects, while sodium hydrosulfide(NaHS) only increased CSE expression and the endogenous H2 S production and had no effect on DR1 expression. Meanwhile, HG significantly increasedthe intracellular calcium concentration ([Ca2+ ]i ),and SKF 38393 further increased HG-induced [Ca2+ ]i . In addition, HG increased the lactate dehydrogenase activity, malondialdehyde and reactive oxygen species contents, apoptotic rate, the expression of cleaved caspase-3, caspase-9, and cytochrome c, and the activity of phosphorylated-inhibitor of nuclear factor-kappaBα (NF-κBα) (p-IκBα) and phosphorylated-NF-κB (p-NF-κB), and reduced cell viability, superoxide dismutase activity, and Bcl-2 expressions. SKF 38393 and NaHS markedly reversed the effect of HG. The effect of SKF 38393 was similar to N-acetyl- l-cysteine (an inhibitor of oxidative stress) or pyrrolidinedithiocarbamate ammonium (an NF-kB inhibitor). Taken together, DR1 upregulates the CSE/H2 S pathway by increasing the [Ca2+ ]i , which inhibits HG-induced apoptosis via downregulating NF-κB/IκBα pathway in vascular endothelial cells.

Dihydromyricetin induces mitophagy by regulating Prohibitin 2 pathway in vascular endothelial cells

Dihydromyricetin induces mitophagy by regulating Prohibitin 2 pathway in vascular endothelial cells

Anti-Inflammatory Effects of Heliangin from Jerusalem Artichoke (Helianthus tuberosus) Leaves Might Prevent Atherosclerosis.

Atherosclerosis is considered the major cause of cardiovascular and cerebrovascular diseases, which are the leading causes of death worldwide. Excessive nitric oxide production and inflammation result in dysfunctional vascular endothelial cells, which are critically involved in the initiation and progression of atherosclerosis. The present study aimed to identify a bioactive compound from Jerusalem artichoke leaves with anti-inflammatory activity that might prevent atherosclerosis. We isolated bioactive heliangin that inhibited NO production in LPS-induced macrophage-like RAW 264.7 cells. Heliangin suppressed ICAM-1, VCAM-1, E-selectin, and MCP-1 expression, as well as NF-κB and IκBα phosphorylation, in vascular endothelial cells stimulated with TNF-α. These results suggested that heliangin suppresses inflammation by inhibiting excessive NO production in macrophages and the expression of the factors leading to the development of atherosclerosis via the NF-κB signaling pathway in vascular endothelial cells. Therefore, heliangin in Jerusalem artichoke leaves could function in the prevention of atherosclerosis that is associated with heart attacks and strokes.

Up-regulation of caveolin 1 mediated by chitosan activates Wnt/ β-catenin pathway in chronic refractory wound diabetic rat model

ABSTRACT Diabetes mellitus (DM) can be implicated in the perturbations of vascular integrity and the dysfunction of angiogenesis. Chitosan has the advantage of promoting the vascular endothelial cell proliferation. However, the molecular mechanism of action in the promotion of wound healing by chitosan derivatives is still debated. In the current study, DM with chronic wound (CW) model rats were prepared and treated with chitosan. Vascular endothelial cells isolated from granulation tissues were conducted by RNA sequencing. Two thousand three hundred and sixteen genes were up-regulated, while 1,864 genes were down-regulated after chitosan treatment compared to CW group. Here, we observed that caveolin 1 (CAV1) was highly expressed induced by chitosan. Furthermore, we observed that CAV1 knockdown could compromise the activation of Wnt pathway by reduction of β-catenin in rat aortic endothelial cells (RAOECs) and brain endothelium four cells (RBE4s). Moreover, we determined a direct interaction between CAV1 and β-catenin by IP assay. The C-terminus of CAV1 and β-catenin (24 to 586 amino acids) contributed to the interaction of these two proteins. Finally, the protein docking analysis indicated that the fragments of β-catenin (253–261 ‘FYAITTLHN’ and 292–303 ‘KFLAITTDCLQI’) might have affected the structure by CAV1 and facilitated the resistance to degradation. Taken together, our study demonstrates that chitosan can up-regulate CAV1 expression, and CAV1 can interact with β-catenin for promotion of canonical Wnt signaling pathway activity. Our results deepens the molecular mechanism of the Wnt pathway in vascular endothelial cells and is beneficial to developing new targets to assist in enhancing the pharmacological effect of chitosan on wound healing and angiogenesis against DM.

Protective Effect of Flavonoids from a Deep-Sea-Derived Arthrinium sp. against ox-LDL-Induced Oxidative Injury through Activating the AKT/Nrf2/HO-1 Pathway in Vascular Endothelial Cells.

Oxidized low-density lipoprotein (ox-LDL)-induced oxidative injury in vascular endothelial cells is crucial for the progression of cardiovascular diseases, including atherosclerosis. Several flavonoids have been shown cardiovascular protective effects. Recently, our research group confirmed that the novel flavonoids isolated from the deep-sea-derived fungus Arthrinium sp., 2,3,4,6,8-pentahydroxy-1-methylxanthone (compound 1) and arthone C (compound 2) effectively scavenged ROS in vitro. In this study, we further investigated whether these compounds could protect against ox-LDL-induced oxidative injury in endothelial cells and the underlying mechanisms. Our results showed that compounds 1 and 2 inhibited ox-LDL-induced apoptosis and adhesion factors expression in human umbilical vein vascular endothelial cells (HUVECs). Mechanistic studies showed that these compounds significantly inhibited the ROS level increase and the NF-κB nuclear translocation induced by ox-LDL. Moreover, compounds 1 and 2 activated the Nrf2 to transfer into nuclei and increased the expression of its downstream antioxidant gene HO-1 by inducing the phosphorylation of AKT in HUVECs. Importantly, the AKT inhibitor MK-2206 2HCl or knockdown of Nrf2 by RNA interference attenuated the inhibition effects of these compounds on ox-LDL-induced apoptosis in HUVECs. Meanwhile, knockdown of Nrf2 abolished the effects of the compounds on ox-LDL-induced ROS level increase and the translocation of NF-κB to nuclei. Collectively, the data showed that compounds 1 and 2 protected endothelial cells against ox-LDL-induced oxidative stress through activating the AKT/Nrf2/HO-1 pathway. Our study provides new strategies for the design of lead compounds for related cardiovascular diseases treatment.

Bai-Hu-Tang regulates endothelin-1 and its signalling pathway in vascular endothelial cells

Ethnopharmacological relevanceBai-Hu-Tang (BHT) is traditionally used to treat human and animal fever syndrome with four symptoms: large and vigorous pulse, large thirst, high sweat, and high heat. Aim of the studyTo investigate the mechanism of vasodilation regulation of Bai-Hu-Tang in primary vascular endothelial cells stimulated by lipopolysaccharide (LPS). Materials and methodsA hydrophilic concentrate of BHT was prepared, and the main components of mangiferin and timosaponin BⅡ were determined by HLPC analysis. The rabbit fever model was constructed by intravenous injection of LPS (15 μg/kg body weight), and BHT was gavaged to treat febrile rabbits. After treatment for 6 h, animal peripheral blood was collected, and serum was isolated for endothelin-1 (ET-1) and nitric oxide (NO) assays. Rabbit vascular endothelial cells (RVECs) were isolated and stimulated with 1 μg/mL LPS, and then inflammatory cells were treated with 125 or 250 μg/mL BHT for 24 h. The supernatant cytokines TNF-ɑ, IL-1β, IL-6, and ET-1 were detected by ELISA kits. Gene expression levels of endothelin receptor type B (ETB receptor) were analysed by real-time polymerase chain reaction (RT-PCR), and protein expression levels of PI3K and Akt were detected by Western blot. A nitrite assay was used to measure intracellular nitric oxide (NO) production, and nitric oxide synthase (NOS) was measured by the T-NOS colorimetric method. ResultsAnimal experiments demonstrated that BHT significantly restored ET-1 and NO in animal peripheral blood, which were disordered in LPS-induced fever rabbits. Moreover, a cytotoxicity assay demonstrated that BHT ≤700 μg/mL is innoxious to RVECs. BHT significantly repressed cellular TNF-α, IL-1β, and ET-1, which were originally elevated by LPS in RVECs. Meanwhile, BHT elevated the gene expression level of the ETB receptor and promoted NOS and NO production in RVECs induced by LPS. ConclusionBHT can inhibit excessive ET-1 secretion induced by LPS in vascular endothelial cells and activate the classic ET-1 signalling pathway to promote NO production, which may facilitate vasodilation of smooth muscle cells.

Synthesis of Reactive Sulfur Species in Cultured Vascular Endothelial Cells after Exposure to TGF-β1: Induction of Cystathionine γ-Lyase and Cystathionine β-Synthase Expression Mediated by the ALK5-Smad2/3/4 and ALK5-Smad2/3-ATF4 Pathways.

Transforming growth factor-β1 (TGF-β1) occurs at high levels at damage sites of vascular endothelial cell layers and regulates the functions of vascular endothelial cells. Reactive sulfur species (RSS), such as cysteine persulfide, glutathione persulfide, and hydrogen persulfide, are cytoprotective factors against electrophiles such as reactive oxygen species and heavy metals. Previously, we reported that sodium trisulfide, a sulfane sulfur donor, promotes vascular endothelial cell proliferation. The objective of the present study was to clarify the regulation and significance of RSS synthesis in vascular endothelial cells after exposure to TGF-β1. Bovine aortic endothelial cells in a culture system were treated with TGF-β1 to assess the expression of intracellular RSS, the effect of RSS on cell proliferation in the presence of TGF-β1, induction of RSS-producing enzymes by TGF-β1, and intracellular signal pathways that mediate this induction. The results suggest that TGF-β1 increased intracellular RSS levels to modulate its inhibitory effect on proliferation. The increased production of RSS, probably high-molecular-mass RSS, was due to the induction of cystathionine γ-lyase and cystathionine β-synthase, which are RSS-producing enzymes, and the induction was mediated by the ALK5-Smad2/3/4 and ALK5-Smad2/3-ATF4 pathways in vascular endothelial cells. TGF-β1 regulates vascular endothelial cell functions such as proliferation and fibrinolytic activity; intracellular high-molecular-mass RSS, which are increased by TGF-β1, may modulate the regulation activity in vascular endothelial cells.

Bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signalling pathway

BackgroundAntiangiogenic therapy has increasingly become an important strategy for the treatment of colorectal cancer. Recent studies have shown that the tumour microenvironment (TME) promotes tumour angiogenesis. Bufalin is an active antitumour compound whose efficacy has been indicated by previous studies. However, there are very few studies on the antiangiogenic effects of bufalin.MethodsHerein, human umbilical vein endothelial cell (HUVEC) tube formation, migration and adhesion tests were used to assess angiogenesis in vitro. Western blotting and quantitative PCR were used to detect relevant protein levels and mRNA expression levels. A subcutaneous xenograft tumour model and a hepatic metastasis model were established in mice to investigate the influence of bufalin on angiogenesis mediated by the TME in vivo.ResultsWe found that angiogenesis mediated by cells in the TME was significantly inhibited in the presence of bufalin. The results demonstrated that the proangiogenic genes in HUVECs, such as VEGF, PDGFA, E-selectin and P-selectin, were downregulated by bufalin and that this downregulation was mediated by inhibition of the STAT3 pathway. Overexpression of STAT3 reversed the inhibitory effects of bufalin on angiogenesis. Furthermore, there was little reduction in angiogenesis when bufalin directly acted on the cells in the tumour microenvironment.ConclusionOur findings demonstrate that bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signalling pathway in vascular endothelial cells, revealing that bufalin may be used as a new antiangiogenic adjuvant therapy medicine to treat colorectal cancer.

Ezrin regulates synovial angiogenesis in rheumatoid arthritis through YAP and Akt signalling.

This study aimed to investigate the role and regulatory mechanisms of Ezrin in synovial vessels in rheumatoid arthritis (RA). Synovial tissues were obtained from people with osteoarthritis people and patients with RA patients. We also used an antigen‐induced arthritis (AIA) mice model by using Freund's adjuvant injections. Ezrin expression was analysed by immunofluorescence and immunohistochemical staining in synovial vessels of patients with RA and AIA mice. We investigated the role of Ezrin on vascular endothelial cells and its regulatory mechanism in vivo and in vitro by adenoviral transfection technology. Our results suggest a role for the Ezrin protein in proliferation, migration and angiogenesis of vascular endothelial cells in RA. We also demonstrate that Ezrin plays an important role in vascular endothelial cell migration and tube formation through regulation of the Hippo‐yes‐associated protein 1 (YAP) pathway. YAP, as a key protein, can further regulate the activity of PI3K/Akt signalling pathway in vascular endothelial cells. In AIA mice experiments, we observed that the inhibition of Ezrin or of its downstream YAP pathway can affect synovial angiogenesis and may lead to progression of RA. In conclusion, Ezrin plays an important role in angiogenesis in the RA synovium by regulating YAP nuclear translocation and interacting with the PI3K/Akt signalling pathway.

Anoikis resistant gastric cancer cells promote angiogenesis and peritoneal metastasis through C/EBPβ-mediated PDGFB autocrine and paracrine signaling

Anoikis is a type of programmed cell death induced by loss of anchorage to the extracellular matrix (ECM). Anoikis resistance (AR) is crucial for the survival of metastatic cancer cells in blood, lymphatic circulation and distant organs. Compared to ordinary cancer cells, anoikis resistant cancer cells undergo various cellular and molecular alterations, probably characterizing the cells with unique features not limited to anoikis resistance. However, the molecular mechanisms connecting anoikis resistance to other metastatic properties are still poorly understood. Here, the biological interaction between anoikis resistance and angiogenesis as well as their involvement into peritoneal metastasis of gastric cancer (GC) were investigated in vitro and in vivo. The prognostic value of key components involved in this interaction was evaluated in the GC cohort. Compared to ordinary GC cells, GCAR cells exhibited stronger metastatic and pro-angiogenic traits corresponding to elevated PDGFB secretion. Mechanistically, transcription factor C/EBPβ facilitated PDGFB transcription by directly binding to and interacting with PDGFB promoter elements, subsequently increasing PDGFB secretion. Secreted PDGFB promoted the survival of detached GC cells through a C/EBPβ-dependent self-feedback loop. Moreover, secreted PDGFB promoted angiogenesis in metastases via activation of the MAPK/ERK signaling pathway in vascular endothelial cells. Both C/EBPβ activation level and PDGFB expression were significantly elevated in GC and correlated with metastatic progression and poor prognosis of patients with GC. Overall, interaction between GCAR cells and vascular endothelial cells promotes angiogenesis and peritoneal metastasis of GC based on C/EBPβ-mediated PDGFB autocrine and paracrine signaling. C/EBPβ-PDGFB-PDGFRβ-MAPK axis promises to be potential prognostic biomarkers and therapeutic targets for peritoneal metastasis of GC.

Theaflavin alleviates oxidative injury and atherosclerosis progress via activating microRNA-24-mediated Nrf2/HO-1 signal.

Theaflavin (TF) in black tea has been shown to have significant antioxidant and anti-inflammatory capacity; however, the effects and the underlying mechanism of TF on atherosclerosis (AS) remain unclear. Herein, we investigated the effects and the potential mechanism of TF on AS progression in vivo and in vitro. ApoE-/- mice were administrated with high fat diet (HFD) or HFD + TF (5 or 10mg, i.g.) for 12 weeks. The results indicated that TF administration effectively decreases the serum lipid levels and the production of MDA in HFD-fed mice. Meanwhile, TF promotes the activities of antioxidant enzymes (SOD, CAT, and GSH-Px) and inhibits the formation of atherosclerotic plaque and the process of histological alterations in the aorta. In vitro, TF pretreatment could protect against cholesterol-induced oxidative injuries in HUVEC cells, decreasing the level of ROS and MDA, maintaining the activities of antioxidant enzymes. Further study revealed that TF upregulates Nrf2/HO-1 signaling pathway in vascular endothelial cells. Moreover, TF increases the level of microRNA-24 (miR-24), and miR-24 inhibition markedly compromises TF-induced Nrf2 activation and protective effects. In conclusion, the present study indicated that theaflavins may achieve the anti-atherosclerotic effect via activating miR-24-mediated Nrf2/HO-1 signaling pathway.