Vein Endothelial Cells Research Articles

Hepatic sinusoids versus central veins: Structures, markers, angiocrines, and roles in liver regeneration and homeostasis.

The blood circulates through the hepatic sinusoids delivering nutrients and oxygen to the liver parenchyma and drains into the hepatic central vein, yet the structures and phenotypes of these vessels are distinctively different. Sinusoidal endothelial cells are uniquely fenestrated, lack basal lamina and possess organelles involved in endocytosis, pinocytosis, degradation, synthesis and secretion. Hepatic central veins are nonfenestrated but are also active in synthesis and secretion. Endothelial cells of sinusoids and central veins secrete angiocrines that play respective roles in hepatic regeneration and metabolic homeostasis. The list of markers for identifying sinusoidal endothelial cells is long and their terminologies are complex. Further, their uses vary in different investigations and, in some instances, could be confusing. Central vein markers are fewer but more distinctive. Here we analyze and categorize the molecular pathways/modules associated with the sinusoid-mediated liver regeneration in response to partial hepatectomy and chemical-induced acute or chronic injury. Similarly, we highlight the findings that central vein-derived angiocrines interact with Wnt/β-catenin in perivenous hepatocytes to direct gene expression and maintain pericentral metabolic zonation. The proposal that perivenous hepatocytes behave as stem/progenitor cells to provoke hepatic homeostatic cell renewal is reevaluated and newer concepts of broad zonal distribution of hepatocyte proliferation in liver homeostasis and regeneration are updated. Thus, this review integrates the structures, biology and physiology of liver sinusoids and central veins in mediating hepatic regeneration and metabolic homeostasis.

Abstract 15183: Thrombopoietin Has a Protective Effect Against Apoptosis of Endothelial Cells Through Activating Pi3k/akt Pathway

Introduction: Thrombopoietin (TPO) is a hematopoietic growth factor for platelet lineage. TPO was found to be neuroprotective in hypoxic-ischemic neonatal rat brain models and treatment with TPO reduced brain damage and improved sensorimotor functions (Li L et al, Aging-US, 2020). However, the underlying mechanism of TPO in this model, and its role in neural cells and endothelial cells were still unclear. Methods: C17.2 cells were divided into control (0.5% FCS), Normal (10% FCS), TPO and TPO + LY294002 groups. Human umbilical vein endothelial (HUVEC) cells were divided in to normal, CoCl 2 , TPO and TPO + CoCl2 groups. The expressed of TPO and c-mpl was tested by RT-PCR. The cell viability and apoptosis of each group were tested by Cell Counter Kit 8 (CCK-8) assay and flow cytometry. The expression of Caspase-3 and mitochondrial membrane potential (MMP) were then determined by flow cytometry with Caspase-3-PE and JC-1. The effect of TPO in PI3K/AKT pathway was detected by using Western blot. Results: Both TPO and c-mpl are expressed in the neurons of the human CNS. TPO was also detected in human cerebrospinal fluid. TPO promoted C17.2 cell proliferation through activation of the PI3K/Akt signaling pathway. Via the Bcl-2/BAX signaling pathway, TPO exerted an anti-apoptotic effect by suppressing mitochondria membrane potentials. We also investigated the protective effect of TPO on human endothelial cells. CoCl 2 significantly inhibited the growth of HUVECs. The cell viability of HUVECs decreased gradually with the enhancement of CoCl2 at a gradient of chemical concentrations (r= -0.997). CoCl 2 dramatically increased apoptosis of HUVECs, whereas pre-treatment with TPO rescued cell apoptosis induced by CoCl 2 (P<0.001). Further investigation found that TPO decreased the expression of Caspase-3 and inhibited the reduction of MMP induced by CoCl 2 (P<0.05). TPO increased the activation of PI3K/AKT pathway in HUVECs. Conclusions: TPO has a protective effect against apoptosis of neural cells and endothelial cells through activating the PI3K/AKT pathway, thus decreasing the expression of apoptosis protease Caspase-3 and inhibiting the reduction of MMP.

C-C Motif Chemokine 8 promotes angiogenesis in vascular endothelial cells.

Angiogenesis is an important progress associated with several pathological situations. Several chemokines have been reported to act as regulators of angiogenesis. The current study aimed to find whether C-C Motif Chemokine 8 is involved in angiogenesis regulation. To verify whether C-C Motif Chemokine 8 is related to angiogenesis in plaques, carotid plaques were collected from patients with severe carotid stenosis and analysed using CD31 immunohistochemistry and real-time PCR. To further clarify the relation between C-C Motif Chemokine 8 and angiogenesis, human umbilical vein endothelium cells and human dermal microvascular endothelial cells were treated with C-C Motif Chemokine 8 in the presence or absence of C-C motif chemokine receptor 2-Ab and extracellular regulated MAP kinase 1/2 inhibition (FR180204). Proliferation and migration of human umbilical vein endothelium cells and human dermal microvascular endothelial cells were examined with Cell Counting Kit-8 and Transwell chamber assay, respectively. In vitro angiogenesis stimulated by C-C Motif Chemokine 8 was examined using tube formation assay. Ex vivo and in vivo angiogenesis were assessed by mice aortic ring assay and Matrigel plug assay, respectively. C-C motif chemokine receptors of human umbilical vein endothelium cells were examined with real-time PCR, and C-C motif chemokine receptor 1, C-C motif chemokine receptor 2, extracellular regulated MAP kinase 1/2 and phosphorylation-extracellular regulated MAP kinase 1/2 were examined with western blotting assay. C-C Motif Chemokine 8 was increased in carotid plaques with severe angiogenesis in both RNA and protein level. C-C Motif Chemokine 8 (5 ng/ml) weakly increased human umbilical vein endothelium cell proliferation, but not on human dermal microvascular endothelial cells. Migration and tube formation could be induced by C-C Motif Chemokine 8 in both human umbilical vein endothelium cells and human dermal microvascular endothelial cells. In mice aortic ring assay and Matrigel plug assay, C-C Motif Chemokine 8 could promote angiogenesis compared to vehicle groups. Phosphorylation of extracellular regulated MAP kinase 1/2 was increased with C-C Motif Chemokine 8 stimulation. The migration and tube formation promoted by C-C Motif Chemokine 8 could be largely blocked by C-C motif chemokine receptor 2-Ab or extracellular regulated MAP kinase 1/2 inhibition (FR180204). C-C Motif Chemokine 8 could promote both in vitro and in vivo angiogenesis. C-C motif chemokine receptor 2 played an important role in the activation of C-C Motif Chemokine 8 and extracellular regulated MAP kinase 1/2 signalling pathway was involved in this mechanism.

Protein Adsorption on Biomaterial Surfaces: Subsequent Conformational and Biological Consequences – A Review

Protein adsorption on solid surfaces is an immensely complex event comprising versatile biological and physico-chemical factors. This review focuses to ascertain the nature and biocompatibility of solid matrices essential for the medical needs during prosthetic implantations. It deals with number of important factors; nature of the biomaterial surfaces, the native protein structure, and induced configurational changes during the adsorbed state, andphysico-chemical influences liable for the event. The adsorption process demonstrates that solid surfaces are enabling to alter the protein structure. The conversion of neutral zymogens factor XII, and factor VII (FXII and FVII) to active enzymatic state (FXIIa and FVIIa) initiating the blood coagulation cascade following intrinsic or extrinsic pathway is a prime example regarding the configuration alteration during adsorbed state compared to its nativestate. Additionally, the activation of the complement cascade arises as a result of immune activation due to the adsorbed proteins on solid matrices. It is well known that interfacial tension compels the protein molecules to alter their structure, and is the prime factor behind the configuration transformation. Influences like contact angle, wettability, zeta potential and hydrophobicity along with other inter-aligned forces are involved. It is found that hydrophobic surfaces allow more proteins to bind but fail to activate the coagulation cascade. Contrarily, hydrophilic surfaces despite the feeble adsorption ability impose adequate changes to induce the enzymatic action. The nature of adsorption at the stationary state has been explained following the Gibbs' model of surface excess, Langmuir or any of the equivalent paradigms. But uniqueness in adsorption behavior is noticed in the ‘Vroman effect' while undergoing multiple protein interaction on the solid surfaces. Additionally, the property of cell adhesion heavily relies on the surface matter. Hydrophobicity, surface charge, chemical composition, and topography concertedly play crucial role. Further, prior adsorption of proteins on the adsorbent imposes profound effect on the cell and microbial adhesions which obviously depends on the character of proteins, and cells including the surface chemical composition of the adsorbents. The incident of bio-fouling which often enforces harmful effect arising from various implants is primarily instigated by the adsorption of proteins leading to subsequent invasion prompted by the immune cells. For avoidance, special categories of biomaterials are in the process of manufacturing. Despite having numerous adverse effects, cellular adhesion also shows few beneficial roles, like enhancing the growth of human vein endothelium cells and neurons. The adhesion of bacteria or microorganisms on many solid surfaces induces significantly different effects maintaining their longer survival period.

RETRACTED ARTICLE: M2 macrophage-derived extracellular vesicles promote gastric cancer progression via a microRNA-130b-3p/MLL3/GRHL2 signaling cascade

BackgroundTransfer of noncoding microRNAs (miRNAs) by extracellular vesicles (EVs) promotes the development of chemoresistance in many tumor types. Additionally, restoration or depletion of several miRNAs has been observed in multiple cancer types including gastric cancer (GC). In this present study, we aimed to investigate the mechanism of miR-130b-3p in M2 macrophage-derived EVs in the development of GC through regulation of mixed lineage leukemia 3 (MLL3) and grainyhead-like 2 (GRHL2).MethodsExpression of miR-130b-3p and GRHL2 was quantified in 63 pairs of cancerous and noncancerous gastric tissues. The predicted binding between miR-130b-3p and MLL3, together with the enrichment of MLL3, H3K4me1, and H3K27ac in gene enhancer region, was verified by luciferase activity assay and chromatin immunoprecipitation. Effects of miR-130b-3p on GC cell proliferation, apoptosis, migration and invasion, as well as tube formation of human umbilical endothelial vein cells (HUEVCs) were further determined by gain- and loss-of function assays in vitro.ResultsmiR-130b-3p was upregulated in GC tissues, and miR-130b-3p promoted survival, metastasis and angiogenesis of GC cells as well as enhanced tumor formation and angiogenesis in GC in vivo. Additionally, miR-130b-3p delivered in M2 macrophage-derived EVs promoted survival, migration, invasion, and angiogenesis of GC cells. Notably, MLL3 inhibited GC cell proliferation, migration, invasion, and vessel-like tube formation of HUEVCs by increasing GRHL2. Furthermore, downregulation of miR-130b-3p in M2 macrophage-derived EVs or upregulation of GRHL2 inhibited tumor formation and angiogenesis in GC.ConclusionThis study highlights that EVs loaded with the specific miRNA cargo miR-130b-3p mediate communication between M2 macrophages and cancer cells in the tumor microenvironment through the modulation of MLL3 and GRHL2 in GC.

Novel fibrin-fibronectin matrix accelerates mice skin wound healing

Plasma fibrinogen (F1) and fibronectin (pFN) polymerize to form a fibrin clot that is both a hemostatic and provisional matrix for wound healing. About 90% of plasma F1 has a homodimeric pair of γ chains (γγF1), and 10% has a heterodimeric pair of γ and more acidic γ′ chains (γγ′F1). We have synthesized a novel fibrin matrix exclusively from a 1:1 (molar ratio) complex of γγ′F1 and pFN in the presence of highly active thrombin and recombinant Factor XIII (rFXIIIa). In this matrix, the fibrin nanofibers were decorated with pFN nanoclusters (termed γγ′F1:pFN fibrin). In contrast, fibrin made from 1:1 mixture of γγF1 and pFN formed a sporadic distribution of “pFN droplets” (termed γγF1+pFN fibrin). The γγ′F1:pFN fibrin enhanced the adhesion of primary human umbilical vein endothelium cells (HUVECs) relative to the γγF1+FN fibrin. Three dimensional (3D) culturing showed that the γγ′F1:pFN complex fibrin matrix enhanced the proliferation of both HUVECs and primary human fibroblasts. HUVECs in the 3D γγ′F1:pFN fibrin exhibited a starkly enhanced vascular morphogenesis while an apoptotic growth profile was observed in the γγF1+pFN fibrin. Relative to γγF1+pFN fibrin, mouse dermal wounds that were sealed by γγ′F1:pFN fibrin exhibited accelerated and enhanced healing. This study suggests that a 3D pFN presentation on a fibrin matrix promotes wound healing.

Toward understanding the prolonged circulation and elimination mechanism of crosslinked polymeric micelles in zebrafish model

Understanding the behaviors of nanomedicines in vivo is one of the most important prerequisites for the design and optimization of nanomedicines. However, the in vivo tracking of nanomedicines in rodents is severely limited by the restricted imaging possibilities within these animals. To meet these needs, the FRET (fluorescence or Förster resonance energy transfer) imaging combined with visual zebrafish larvae model (7 dpf) was used to study the behaviors of polymeric micelles in vivo at high spatiotemporal resolution. Firstly, the FRET ordinary Pluronic micelles (OPMs) and disulfide bond crosslinked Pluronic micelles (CPMs) were synthesized to quantify their integrity in vitro and in vivo by FRET ratio. The behaviors and integrity of OPMs and CPMs in vivo were visually investigated in zebrafish larvae across the entire living organism and at cellular molecular level after intravenous microinjection. Results showed that OPMs were rapidly disassociated in circulation, then largely sequestrated by the endothelial cells (ECs) of caudal vein (CV) and liver in zebrafish larvae, which resulted in quick elimination from blood circulation. While the CPMs were more stable and escaped the sequestration by ECs of CV and liver, which prolonged their circulation in blood. Moreover, we pioneered to use the zebrafish model to reveal that polymeric micelles were eliminated through hepatobiliary pathway after disassociation. While the intact micelles were relatively difficult to eliminate. We further verified that the scavenger receptors of ECs but not the macrophages mainly mediated the elimination of polymeric micelles in CV and liver of zebrafish larvae. These finding on behaviors and elimination mechanisms of polymeric micelles in zebrafish model could contribute to the rational design and optimization of nanomedicines, further guide their studies in rodents.

Epigallocatechin-3-gallate (EGCG) Alters Histone Acetylation and Methylation and Impacts Chromatin Architecture Profile in Human Endothelial Cells.

Epigallocatechin gallate (EGCG), the main green tea polyphenol, exerts a wide variety of biological actions. Epigenetically, the catechin has been classified as a DNMTs inhibitor, however, its impact on histone modifications and chromatin structure is still poorly understood. The purpose of this study was to find the impact of EGCG on the histone posttranslational modifications machinery and chromatin remodeling in human endothelial cells of both microvascular (HMEC-1) and vein (HUVECs) origin. We analyzed the methylation and acetylation status of histones (Western blotting), as well as assessed the activity (fluorometric assay kit) and gene expression (qPCR) of the enzymes playing a prominent role in shaping the human epigenome. The performed analyses showed that EGCG increases histone acetylation (H3K9/14ac, H3ac), and methylation of both active (H3K4me3) and repressive (H3K9me3) chromatin marks. We also found that the catechin acts as an HDAC inhibitor in cellular and cell-free models. Additionally, we observed that EGCG affects chromatin architecture by reducing the expression of heterochromatin binding proteins: HP1α, HP1γ. Our results indicate that EGCG promotes chromatin relaxation in human endothelial cells and presents a broad epigenetic potential affecting expression and activity of epigenome modulators including HDAC5 and 7, p300, CREBP, LSD1 or KMT2A.

Expression of vascular endothelial growth factor and its receptors in infertile men with varicocele

ObjectivesAn enlargement of the spermatic vein is known as a varicocele. Research studies suggest that immune system mediators such as vascular endothelial growth factor (VEGF) and its receptors including VEGFR1, VEGFR2, and VEGFR3 can play a role in angiogenesis and inhibition of endothelial cell apoptosis and correspondingly suppress spermatogenesis. Thus, the purpose of this study was to measure the expression of VEGF and its receptors in infertile men with varicocele. Materials & MethodsTo meet the research objectives, a total number of 30 infertile male patients affected with varicocele (Grade 3) and 30 healthy fertile male subjects without any varicocele or urogenital tract disorder were enrolled in the study. The varicose and normal veins were obtained from the patients along with the blood flowing in these spermatic veins during surgery. Also, peripheral blood samples were collected from the mentioned patients and healthy subjects. The serum levels of VEGF were also measured via enzyme-linked immunosorbent assay (ELISA) and subsequently mRNA level of VEGFR1, VEGFR2, VEGFR3, B Cell Lymphoma-Associated X (Bax), and B-cell lymphoma 2 (Bcl2) genes were measured using the real-time polymerase chain reaction (RT-PCR) technique. ResultsThe findings of this study revealed that VEGFR2 gene expression in varicose veins was significantly increased compared with normal veins in varicocele patients (P < 0.001) and Bax/Bcl2 ratio reduced in varicose veins when compared to normal veins of the patients (P < 0.05). Our findings also showed a significant rise in the serum levels of VEGF in the peripheral blood and varicose vein bloodstream compared with those in healthy subjects (P < 0.0001). Moreover, a significant difference was observed in the serum levels of VEGF in the peripheral blood and varicose vein blood of patients suffering from varicocele (P < 0.001). ConclusionAccording to the results of this study, VEGF/VEGFR2 axis might act in the survival of endothelial cells of varicocele vein through inhibition of apoptosis and stimulation of angiogenesis. Additionally, increased VEGF in the testis can probably play a role in suppressing spermatogenesis and varicocele-based infertility.

Effects of early pregnancy on expression of interferon-stimulated gene 15, STAT1, OAS1, MX1, and IP-10 in ovine liver.

Interferon-tau (IFNT) regulates maternal recognition during early pregnancy in ruminants. The liver can serve as a hematopoietic organ, and it has immune functions. This study hypothesized whether mRNA and proteins of interferon-stimulated genes (ISGs) induced by early pregnancy are upregulated in maternal liver. Therefore, we determined the expression of interferon-stimulated gene 15-kDa protein (ISG15), 2',5'-oligoadenylate synthetase 1 (OAS1), myxovirus resistance protein 1 (MX1), interferon-gamma-inducible protein 10 (IP-10), and signal transducer and activator of transcription 1 (STAT1) in maternal livers during early pregnancy in sheep. Ovine livers were sampled on day 16 of the estrous cycle, and days 13, 16, and 25 of pregnancy, and expression of ISGs was detected by quantitative real-time PCR, Western blot, and immunohistochemistry analysis. Our results showed that there were increases in expression of the mRNA and proteins of ISG15, OAS1, IP-10, STAT1, and MX1 during early pregnancy. STAT1 protein was limited to the hepatocytes, and endothelial cells of proper hepatic arteries and hepatic portal veins. In conclusion, the upregulation of ISG15, OAS1, IP-10, STAT1, and MX1 proteins may be implicated in maternal hepatic immune adjustment and other functions during early pregnancy in sheep.

Quantitative morphological evaluation of structural reconstruction in endothelial cells of arteries and veins of testes in the conditions at postresection pulmonary arterial hypertension

Removal of the right or left lung can lead to postresection pulmonary arterial hypertension, venous stasis in the organs of the great circle of blood circulation and structural and functional changes in them. Morphological reconstruction of endotheliocytes of arteries and veins of testes at postresection pulmonary arterial hypertension are insufficiently studied. The purpose of our study was to conduct a quantitative morphological evaluation of structural changes of endothelial cells of the arteries and veins of the testes at postresection pulmonary arterial hypertension. The testes of 46 white male rats, which were divided into 3 groups, were morphological examined. The 1st group consisted of 14 intact animals, 2st – 22 rats with postresection pulmonary arterial hypertension and compensated cor pulmonale, 3st – 10 animals with postresection pulmonary hypertension and decompensated cor pulmonale. Postresection pulmonary arterial hypertension and cor pulmonale were modeled by performing right pulmonectomy in rats. Euthanasia of rats was performed by bloodletting under conditions of thiopental anesthesia one month after the start of the experiment. From the testes were made micropreparations, which morphometrically determined the height of endothelial cells of arteries and veins, the diameter of their nuclei, nuclear-cytoplasmic ratios in these cells, the relative volumes of damaged endotheliocytes. Quantitative indicators were processed statistically. In the conditions of postresection pulmonary arterial hypertension and decompensated pulmonary heart, the studied morphometric parameters changed most markedly. The height of endothelial cells of the arteries of the left testis was reduced by 2.9 % (p˂0.05), and the right – by 2.3 %. Nuclear-cytoplasmic ratios in the endotheliocytes of these vessels increased by 7.6 % and 4.7 %, respectively (p˂0.05), and the relative volume of damaged endotheliocytes increased by 11.7 and 9.3 times (p˂0.001). The studied morphometric parameters in the testicular veins increased to a greater extent compared with the arteries. Thus, the height of endothelial cells of the left testis in the 3rd group of observations was statistically significant (p˂0.001) decreased by 5.8 %, and in the right – by 5.4 %. Nuclear-cytoplasmic ratios in the studied structures increased by 8.2 % (p˂0.001) and 6.5 % (p˂0.01), respectively, which indicated a pronounced violation of structural cellular homeostasis. The relative volume of damaged endothelial cells in the veins of the left testis in postresection pulmonary arterial hypertension combined with decompensated heart increased by 17.6, in the right – by 13.0 times (p˂0.001). Optical on histological preparations of testes showed plethora and dilation of venous vessels, which was complicated by hypoxia, dystrophy, necrobiosis of cells and tissues of the studied organ, and in the long term – infiltrative and sclerotic processes. Venous vessels of the microhemocirculatory bed are unevenly dilated, tortuous, full-blooded, with numerous varicose veins and sacculations. Stasis, thrombosis, diapedetic hemorrhages, plasmorrhagia of the walls of venous vessels and paravasal tissues were found in these vessels. Elastic structures in vessels with the phenomena of multiplication, fragmentation and destruction. Endotheliocytes with signs of edema, dystrophically and necrobiotically altered, sometimes desquamated. Analysis of the obtained data revealed that postresection pulmonary arterial hypertension leads to violations of cellular structural homeostasis, an increase in the relative volumes of damaged endotheliocytes in the vascular bed of the testes. The revealed processes dominate in the venous bed of the left testis and in the decompensated cor pulmonale.

Synthesis of AuNPs using plant polyphenols and their potential treatment for age-related macular degeneration

The primary idea behind this study is to synthesize Saudi Origanum vulgare L. extract mediated AuNPs and to investigate their efficacy in significantly treating AMD. The biocompatible AuNPs were tested for their radical scavenging efficiency in vitro. Also, The effects of AuNPs in suppressing the angiogenic protein expression and inflammatory cytokine levels were analyzed in ARPE-19 (human retinal pigment epithelium-19) as well as and human umbilical vein endothelium cell lines in vitro. From the ORAC findings, it was evident that the bio synthesized AuNPs have presented momentous anti-oxidative activity in reducing the apoptosis in H2O2 treated ARPE-19 cell lines. In addition, the biocompatible AuNPs exhibited significant potential in suppressing the LPS stimulated inflammatory reaction in ARPE-19 cell lines while demonstrating inhibitory expression of growth factor in ARPE-19 as well as in umbilical vein endothelium cell lines. The experimental findings in this study have suggested that the synthesized AuNPs are biocompatible with significant potential in defending against angiogenesis, apoptosis, and generation of pro-inflammatory cytokines in AMD disease.

Epigallocatechin-3-gallate inhibits tumor angiogenesis: involvement of endoglin/Smad1 signaling in human umbilical vein endothelium cells

Strategies targeting endoglin are currently being investigated in clinical trials as an anti-angiogenic therapy. The redundancy between endoglin and vascular endothelial growth factor (VEGF) signaling in angiogenesis was verified. Increased endoglin signaling after an anti-VEGF treatment was observed in patients. Treatment with an endoglin-neutralizing antibody increased VEGF signaling in endothelial cells. Therefore, strategies targeting both the endoglin and VEGF pathways were applied to determine whether the anti-angiogenic effects were increased in vitro. Five possible hits for endoglin were identified from 2000 compounds in the Traditional Chinese Medicine Database using Discovery Studio 4.5 Epigallocatechin-3-gallate (EGCG) attenuates angiogenesis by downregulating VEGF; however, researchers have not determined whether its anti-angiogenic effects are mediated by endoglin/Smad1 signaling. A major contribution of this study is that EGCG significantly inhibited the upregulation of endoglin in semaxanib-treated human umbilical vein endothelial cell. Thus, a combination treatment with EGCG and a VEGF tyrosine kinase inhibitor would be appropriate to reverse drug resistance. EGCG alone significantly decreased endoglin/pSmad1 levels in HUVECs. In the angiogenesis assay, the migration, invasion, and tube formation of HUVECs were markedly suppressed by higher concentrations of EGCG. A combination treatment with EGCG and semaxanib further produced increased anti-angiogenic effects. The main contribution of the study indicated that EGCG significantly decreased the semaxanib-induced overexpression of endoglin. Therefore, a combination treatment including EGCG will probably solve the drug resistance to anti-VEGF treatments.

Research of antioxidant and anti-inflammatory activity of rutine complex with bivalent iron

Studies using cell-free systems have shown that chelation of ferrous iron by rutin and formation of the complex (Rt – Fe) resulted in the appearance of site-specific pseudo-peroxidase activity against hydrogen peroxide, but does not affect the ligand’s ability to interact with peroxynitrite. Anti-inflammatory properties of rutin (Rt) and its complex with ferrous iron were studied in vitro under conditions of bacterial lipopolysaccharide (LPS)-induced inflammation in endothelial cells of the human umbilical vein (HUVEC). The Rt – Fe complex at a dose of 50 µmol/L was found to significantly reduce the level of LPS-induced mRNA expression of inflammatory mediators IL-6, IL-1B, IL-8, MCP1 and COX-2 and the level of secretion of IL-6 and IL-8 in the culture medium, while Rt under the same concentration was ineffective. Experiments performed in vivo indicate that prior administration of the Rt – Fe complex in a dose of 12.5 µmol/kg dramatically eliminated LPS-induced pyrogenic reaction of in Wistar rats. From the above data, it can be concluded that complexation with bivalent iron enhances of antioxidant properties of Rt, leads to appearance of anti-inflammatory activity and expands the area of its possible pharmacological use.

OxHDL controls LOX-1 expression and plasma membrane localization through a mechanism dependent on NOX/ROS/NF-κB pathway on endothelial cells

Systemic inflammatory diseases enhance circulating oxidative stress levels, which results in the oxidation of circulating high-density lipoprotein (oxHDL). Endothelial cell function can be negatively impacted by oxHDL, but the underlying mechanisms for this remain unclear. Some reports indicate that the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is also a receptor for oxHDL. However, it is unknown if oxHDL induces increased LOX-1 expression at the plasma membrane, as an event that supports endothelial dysfunction. Therefore, the aims of this study were to determine if oxHDL induces plasma-membrane level changes in LOX-1 and, if so, to describe the underlying mechanisms in endothelial cells. Our results demonstrate that the incubation of arterial or vein endothelial cells with oxHDL (and not HDL) induces the increase of LOX-1 expression at the plasma membrane; effect prevented by LOX-1 inhibition. Importantly, same results were observed in endothelial cells from oxHDL-treated rats. Furthermore, the observed oxHDL-induced LOX-1 expression is abolished by the down-regulation of NOX-2 expression with siRNA (and no others NOX isoforms), by the pharmacological inhibition of NAD(P)H oxidase (with DPI or apocynin) or by the inhibition of NF-κB transcription factor. Coherently, LOX-1 expression is augmented by the incubation of endothelial cells with H2O2 or GSSG even in absence of oxHDL, indicating that the NOX-2/ROS/ NF-κB axis is involved. Interestingly, oxHDL incubation also increases TNF-α expression, cytokine that induces LOX-1 expression. Thus, our results suggest a positive feedback mechanism for LOX-1 receptor during inflammatory condition where an oxidative burst will generate oxHDL from native HDL, activating LOX-1 receptor which in turn will increase the expression of NOX-2, TNF-α and LOX-1 receptor at the plasma membrane. In conclusion, oxHDL-induced translocation of LOX-1 to the plasma membrane could constitute an induction mechanism of endothelial dysfunction in systemic inflammatory diseases.

Resveratrol attenuates hydrogen peroxide-induced aging through upregulation of autophagy in human umbilical vein endothelial cells.

PurposeResveratrol (RESV; trans-3,5,4′-trihydroxystilbene) has emerged as a potential new therapeutic for age-related atherosclerotic diseases. However, the effect of RESV on cellular aging and its underlying mechanisms remain unknown. Therefore, the aim of this study was to examine whether RESV can delay cellular aging through upregulation of autophagy.Materials and methodsHuman umbilical endothelial vein cells (HUVECs) were divided into four groups: the control group, and the hydrogen peroxide (H2O2) alone, H2O2 + RESV pretreatment, and H2O2 + 3-methyladenine (3-MA) + RESV pretreatment intervention groups. The cell viability was evaluated by a cell counting kit-8 assay. Superoxide dismutase (SOD) activity and intracellular reactive oxygen species (ROS) levels were tested using commercial kits. Senescence-related β-galactosidase activities were detected by immunohistochemical staining. The expression levels of aging-related and autophagy-related markers, including phosphorylated Rb (p-Rb), LC3, and p62, with or without RESV were measured by Western blotting.ResultsPretreatment with 10 µM RESV increased the cell viability and SOD levels. The remarkably higher positive rate of senescence-associated β-galactosidase and increased intracellular ROS levels in the H2O2 treatment group were reversed by treatment with 10 µM RESV. As compared to the H2O2 treatment group, 10 µM RESV could upregulate autophagy through the regulation of p-Rb, LC3, and p62 levels. The anti-aging effect of RESV via an autophagy regulation mechanism was further confirmed by the suppression of these effects with 3-MA treatment.ConclusionRESV may reverse and delay the aging process of HUVECs via upregulation of autophagy and could be a candidate therapeutic for age-related atherosclerotic diseases.

Chemerin promotes angiogenesis invivo.

Chemerin acts as a chemotactic factor for leukocyte populations expressing the G protein‐coupled receptor CMKLR1 (ChemR23). It is also an adipocytokine involved in obesity and metabolic syndromes. Previous studies have demonstrated that chemerin promotes angiogenesis in vitro, although the precise mechanism has not been elucidated. In this study, we have investigated whether chemerin regulates angiogenic processes and validated the associated mechanisms. In this study, chemerin stimulated angiogenesis in mice, which was demonstrated using Matrigel plug implantation assay, mouse corneal models of angiogenesis, and ex vivo rat aortic ring assay. To explore the mechanisms by which chemerin induced angiogenesis, we examined the effects of chemerin in human umbilical vein endothelium cells (HUVECs). Chemerin stimulated the differentiation of HUVECs into capillary‐like structures, promoted the proliferation of HUVECs, and functioned as a chemoattractant in migration assays. Chemerin induced the phosphorylation of Akt and p42/44 extracellular signal‐regulated kinase (ERK) in HUVECs and chemerin promotes angiogenesis via Akt and ERK. SiRNA against the chemerin receptor CMKLR1 but not that against another chemerin receptor, CCRL2, completely inhibited the chemerin‐induced migration and angiogenesis of HUVECs, which indicates that chemerin promotes the migration and angiogenic activities of HUVECs mainly through CMKLR1.

Astaxanthin ameliorates cardiomyocyte apoptosis after coronary microembolization by inhibiting oxidative stress via Nrf2/HO-1 pathway in rats.

Coronary microembolization (CME) caused by physical obstruction in coronary microcirculation induces myocardial apoptosis and cardiac dysfunction, and it was reported that the inactivation of the Nrf2/HO-1 signaling was involved in this process. Astaxanthin (AST) is a reddish pigment that belongs to keto-carotenoids. It is also a potent antioxidant and has been reported to activate Nrf2/HO-1 signaling in vein endothelial cells. However, it is still unknown whether AST is able to activate Nrf2/HO-1 signaling pathway to protect cardiac functions from CME in vivo. To address this question, rats were orally administrated with AST or AST plus Zinc protoporphyrin IX (ZnPP, a HO-1 inhibitor), followed by CME modeling operation. Then, cardiac function was evaluated by echocardiographic measurement. Myocardial infarction was measured by HBFP staining, and apoptosis was assessed by TUNEL staining. The protein levels and mRNA expressions of Bax and Bcl-2 were measured by Western blot and qRT-PCR, respectively. ELISA was performed to measure the activity of enzymes related to oxidative stress. AST pretreatment dramatically attenuated CME-induced cardiac dysfunction, myocardial infarction, and cardiomyocyte apoptosis. Mechanistically, AST suppressed CME-induced oxidative stress by re-activating Nrf2/HO-1 signaling. HO-1 inhibitor ZnPP completely eliminated the benefits of AST in CEM, supporting the critical role of Nrf2/HO-1 signaling in mediating the cardioprotective function of AST in CME. Conclusion: AST suppresses oxidative stress via activating Nrf2/HO-1 pathway and thus prevents CME-induced cardiomyocyte apoptosis and ameliorates cardiac dysfunction in rats.

CIZ1 Expression Is Upregulated in Hemangioma of the Tongue.

Hemangioma is a vascular neoplasm and one of the most common benign tumors. The pathogenesis of hemangioma has not been fully understood. CIZ1 (Cip1-interacting zinc finger protein 1) is a nuclear protein and the binding partner of p21. Dysregulation of CIZ1 expression has been reported in various types of cancerous tissues. In this study, we examined CIZ1 expression in hemangioma of the tongue and explored its function in vascular endothelial cells, the proliferative cell type in hemangioma. Immunohistochemistry showed that CIZ1 was highly expressed in hemangioma of the tongue while its expression is minimal in the normal tongue tissues. In vitro, knockdown of CIZ1 expression by shRNA transfection significantly reduced the proliferation and migration of human umbilical vein endothelium cells (HUVECs), suggesting a positive role of CIZ1 in endothelial cell proliferation and migration. Therefore, CIZ1 might involve in pathogenesis of hemangioma of the tongue by regulation of endothelial cell functions.

Erbin plays a critical role in human umbilical vein endothelial cell migration and tubular structure formation via the Smad1/5 pathway.

Angiogenesis is an important process in atherosclerosis. ErbB2 was proved to have an important role in vascular development, but it is still unclear whether Erbin expresses in vessels as well as its location and function in the vessels. In the current study, we investigated the location and function of Erbin in human umbilical veins. The human umbilical veins were prepared, and immunofluorescent analysis was performed to determine the expression of Erbin. Human umbilical vein endothelial cells (HUVECs) were cultured and the lentivirus (LV) containing Erbin RNAi was also prepared. After transfection with the lentivirus, CCK-8 assay and Annexin V-PI assay were used for cell proliferation and apoptosis, respectively. Cell migration was studied using the scratch wound healing assay and the transwell assay. The capillary-like tube formation assay was performed to illustrate the effect of Erbin on HUVEC tube formation. Expression of signaling pathway molecules was assessed with Western blot. The immunofluorescent analysis suggested that Erbin expressed in human umbilical veins and the majority of the Erbin is strongly colocalized in endothelial cells. Although knockdown of Erbin did not affect HUVEC proliferation and apoptosis, it significantly suppressed HUVEC migration and tubular structure formation. Erbin knockdown showed no effect on the ERK1/2 and Smad2/3 signaling pathways but significantly promoted Smad1/5 phosphorylation and nuclear translocation. Ablation of the Smad1/5 pathway decreased the effects of Erbin on endothelial cells. Erbin is mainly localized in endothelial cells in human umbilical veins and plays a critical role in endothelial cell migration and tubular formation via the Smad1/5 pathway.