Blood Vessel Angiogenesis Research Articles

Exosomes derived from BMSCs in osteogenic differentiation promote type H blood vessel angiogenesis through miR-150-5p mediated metabolic reprogramming of endothelial cells

Osteogenesis is tightly coupled with angiogenesis spatiotemporally. Previous studies have demonstrated that type H blood vessel formed by endothelial cells with high expression of CD31 and Emcn (CD31hi Emcnhi ECs) play a crucial role in bone regeneration. The mechanism of the molecular communication around CD31hi Emcnhi ECs and bone mesenchymal stem cells (BMSCs) in the osteogenic microenvironment is unclear. This study indicates that exosomes from bone mesenchymal stem cells with 7 days osteogenic differentiation (7D-BMSCs-exo) may promote CD31hi Emcnhi ECs angiogenesis, which was verified by tube formation assay, qRT-PCR, Western blot, immunofluorescence staining and µCT assays etc. in vitro and in vivo. Furthermore, by exosomal miRNA microarray and WGCNA assays, we identified downregulated miR-150-5p as the most relative hub gene coupling osteogenic differentiation and type H blood vessel angiogenesis. With bioinformatics assays, dual luciferase reporter experiments, qRT-PCR and Western blot assays, SOX2(SRY-Box Transcription Factor 2) was confirmed as a novel downstream target gene of miR-150-5p in exosomes, which might be a pivotal mechanism regulating CD31hi Emcnhi ECs formation. Additionally, JC-1 immunofluorescence staining, Western blot and seahorse assay results showed that the overexpression of SOX2 could shift metabolic reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis to enhance the CD31hi Emcnhi ECs formation. The PI3k/Akt signaling pathway might play a key role in this process. In summary, BMSCs in osteogenic differentiation might secrete exosomes with low miR-150-5p expression to induce type H blood vessel formation by mediating SOX2 overexpression in ECs. These findings might reveal a molecular mechanism of osteogenesis coupled with type H blood vessel angiogenesis in the osteogenic microenvironment and provide a new therapeutic target or cell-free remedy for osteogenesis impaired diseases.

Bone marrow cells contribute to seven different endothelial cell populations in the heart

Understanding the mechanisms underlying vascular regeneration in the heart is crucial for developing novel therapeutic strategies for myocardial ischemia. This study investigates the contribution of bone marrow-derived cells to endothelial cell populations in the heart, and their role in cardiac function and coronary circulation following repetitive ischemia (RI). Chimeric rats were created by transplanting BM cells from GFP female rats into irradiated male recipients. After engraftment chimeras were subjected to RI for 17 days. Vascular growth was assessed from recovery of cardiac function and increases in myocardial blood flow during LAD occlusion. After sorting GFP+ BM cells from heart and bone of Control and RI rats, single-cell RNA sequencing was implemented to determine the fate of BM cells. Our in vivo RI model demonstrated an improvement in cardiac function and myocardial blood flow after 17 days of RI with increased capillary density in the rats subjected to RI compared to Controls. Single-cell RNA sequencing of bone marrow cells isolated from rats' hearts identified distinct endothelial cell (EC) subpopulations. These ECs exhibited heterogeneous gene expression profiles and were enriched for markers of capillary, artery, lymphatic, venous, and immune ECs. Furthermore, BM-derived ECs in the RI group showed an angiogenic profile, characterized by upregulated genes associated with blood vessel development and angiogenesis. This study elucidates the heterogeneity of bone marrow-derived endothelial cells in the heart and their response to repetitive ischemia, laying the groundwork for targeting specific subpopulations for therapeutic angiogenesis in myocardial ischemia.

Experimental study of Pruthvisara taila in excised wound model in Wistar albino rats

Pruthvisara taila is a formulation indicated in the chikitsa of vrana as topical medicine in classical text Chakradatta. It contains Shuddha chitrakamoola, Shuddha vatsanabha, Shuddha karaveera, Nirgundi moola, Nadibeeja, Kanji and Karanja taila as the base. Aims and Objectives: Evaluation of wound healing property of Pruthvisara taila through experimental study. Methodology: Wound healing property in albino rats by excision wound healing model and its histopathology study. Results: Results of the study on the parameters assessed like percentage of wound contraction and histopathology study; percentage of wound closure was observed in Control group was 94.92%, in standard it was 93.73% and in test drug the percentage of wound contraction was 95.73%.The test drug, Pruthvisara taila showed more angiogenesis and formation of new blood vessels than standard group and in control group there was absence of formation of new blood vessels and proliferation of fibroblast cells. The control group did not show any collagen formation and scab formation the test drug Pruthvisara taila showed moderate formation and deposition compared to standard drug. Compared to control and standard group, the test drug, Pruthvisara taila selected in this study showed remarkable wound healing property in excised wound.

Isolation and characterization of ZK002, a novel dual function snake venom protein from Deinagkistrodon acutus with anti-angiogenic and anti-inflammatory properties.

Introduction: Pathological angiogenesis, the abnormal or excessive generation of blood vessels, plays an important role in many diseases including cancer, diabetic retinopathy, psoriasis, and arthritis. Additionally, increasing evidence supports the close linkage between angiogenesis and inflammation. Snake venoms are a rich natural source of biologically active molecules and carry rich potential for the discovery of anti-angiogenic and anti-inflammatory modulators. Methods: Here, we isolated and purified a novel protein, ZK002, from the venom of the snake Deinagkistrodon acutus, and investigated its anti-angiogenic and anti-inflammatory activities and mechanisms. Results: ZK002 was identified as a 30kDa heterodimeric protein of α and β chains, which exhibited anti-angiogenic activity in various in vitro assays. Mechanistically, ZK002 inhibited activation of VEGF signaling and related mediators including eNOS, p38, LIMK, and HSP27. ZK002 also upregulated the metalloproteinase inhibitor TIMP3 and inhibited components of the VEGF-induced signaling cascade, PPP3R2 and SH2D2A. The anti-angiogenic activity of ZK002 was confirmed in multiple in vivo models. ZK002 could also inhibit the in vitro expression of pro-inflammatory cytokines, as well as in vivo inflammation in the carrageenin-induced edema rat model. Conclusion: Our findings highlight the potential for further development of ZK002 as a dual function therapeutic against diseases with involvement of pathogenic angiogenesis and chronic inflammation.

T-Cadherin Deficiency Is Associated with Increased Blood Pressure after Physical Activity.

T-cadherin is a regulator of blood vessel remodeling and angiogenesis, involved in adiponectin-mediated protective effects in the cardiovascular system and in skeletal muscles. GWAS study has previously demonstrated a SNP in the Cdh13 gene to be associated with hypertension. However, the role of T-cadherin in regulating blood pressure has not been experimentally elucidated. Herein, we generated Cdh13∆Exon3 mice lacking exon 3 in the Cdh13 gene and described their phenotype. Cdh13∆Exon3 mice exhibited normal gross morphology, life expectancy, and breeding capacity. Meanwhile, their body weight was considerably lower than of WT mice. When running on a treadmill, the time spent running and the distance covered by Cdh13∆Exon3 mice was similar to that of WT. The resting blood pressure in Cdh13∆Exon3 mice was slightly higher than in WT, however, upon intensive physical training their systolic blood pressure was significantly elevated. While adiponectin content in the myocardium of Cdh13∆Exon3 and WT mice was within the same range, adiponectin plasma level was 4.37-fold higher in Cdh13∆Exon3 mice. Moreover, intensive physical training augmented the AMPK phosphorylation in the skeletal muscles and myocardium of Cdh13∆Exon3 mice as compared to WT. Our data highlight a critically important role of T-cadherin in regulation of blood pressure and stamina in mice, and may shed light on the pathogenesis of hypertension.

Vasculature cells control neuroglial co-localization and synaptic connection in a central nervous system tissue mimic system.

Despite the development of neural tissue differentiation methods using a wide variety of stem cells and compartments, there is no standardized strategy for establishing synapses. As the neuronal network is developed in parallel with blood vessel angiogenesis in the central nervous system (CNS) from the embryonic period, we examined neuron-astrocyte-vasculature interactions to understand the effect of the vasculature on the development and stabilization of neurological morphogenesis. We generated a cellular co-culture module targeting the CNS that was embedded in a collagen-based extracellular matrix (ECM) gel. Our neuron-astrocyte-vascular complex module identified the neurological co-localization effect by endothelial cells, as well as the pericyte-induced improvement of synaptic connections. Furthermore, it was suggested that the PDGF, BDNF, IGF, and WNT/BMP pathways were upregulated in synaptic connections enhanced conditions, which are composed of neurexin. These results suggest that the integrity of the vasculature cells in the CNS is important for the establishment of neuronal networks and for synapse connection.

Enhanced external counterpulsation improves dysfunction of forearm muscle caused by radial artery occlusion.

This study aimed to investigate the therapeutic effect of enhanced external counterpulsation (EECP) on radial artery occlusion (RAO) through the oscillatory shear (OS) and pulsatile shear (PS) models of human umbilical vein endothelial cells (HUVECs) and RAO dog models. We used high-throughput sequencing data GSE92506 in GEO database to conduct time-series analysis of functional molecules on OS intervened HUVECs, and then compared the different molecules and their functions between PS and OS. Additionally, we studied the effect of EECP on the radial artery hemodynamics in Labrador dogs through multi-channel physiological monitor. Finally, we studied the therapeutic effect of EECP on RAO at the histological level through Hematoxylin-Eosin staining, Masson staining, ATPase staining and immunofluorescence in nine Labrador dogs. With the extension of OS intervention, the cell cycle decreased, blood vessel endothelial cell proliferation and angiogenesis responses of HUVECs were down-regulated. By contrast, the inflammation and oxidative stress responses and the related pathways of anaerobic metabolism of HUVECs were up-regulated. Additionally, we found that compared with OS, PS can significantly up-regulate muscle synthesis, angiogenesis, and NO production related molecules. Meanwhile, PS can significantly down-regulate inflammation and oxidative stress related molecules. The invasive arterial pressure monitoring showed that 30Kpa EECP treatment could significantly increase the radial artery peak pressure (p = 0.030, 95%CI, 7.236-82.524). Masson staining showed that RAO significantly increased muscle interstitial fibrosis (p = 0.002, 95%CI, 0.748-2.128), and EECP treatment can reduce this change (p = 0.011, 95%CI, -1.676 to -0.296). ATPase staining showed that RAO significantly increased the area of type II muscle fibers (p = 0.004, 95%CI, 7.181-25.326), and EECP treatment could reduce this change (p = 0.001, 95%CI, -29.213 to -11.069). In addition, immunofluorescence showed that EECP increased angiogenesis in muscle tissue (p = 0.035, 95%CI, 0.024-0.528). EECP improves interstitial fibrosis and hypoxia, and increases angiogenesis of muscle tissue around radial artery induced by RAO.

Eyesight to the Blind-Pharmacotherapy for Retinopathy of Prematurity.

Retinopathy of prematurity (ROP) places preterm infants at significant risk for blindness. Angiogenesis of retinal blood vessels relies on vascular endothelial growth factor (VEGF) released in response to physiologic in utero hypoxia. Relative hyperoxia and disruption in the supply of growth factors after preterm birth lead to cessation of normal vascular growth. Recovery of VEGF production after 32 weeks' postmenstrual age results in aberrant vascular growth, including the formation of fibrous scars with the potential to detach the retina. Ablation of aberrant vessels by mechanical or pharmacologic methods relies on timely diagnosis in the early stages of ROP. Mydriatic medications dilate the pupil to allow examination of the retina. Mydriasis is typically accomplished using a combination of topical phenylephrine, a potent alpha-receptor agonist, and cyclopentolate, an anticholinergic. Systemic absorption of these agents results in a high incidence of cardiovascular, gastrointestinal, and respiratory adverse effects. Procedural analgesia should include the topical anesthetic proparacaine, oral sucrose, and nonpharmacologic interventions like non-nutritive sucking. Analgesia is often incomplete, leading to investigation of systemic agents like oral acetaminophen. If ROP threatens retinal detachment, laser photocoagulation is utilized to arrest vascular growth. More recently, the VEGF-antagonists, bevacizumab and ranibizumab, have emerged as treatment options. Systemic absorption of intraocular bevacizumab and the profound consequences of diffuse disruption of VEGF in the setting of rapid, neonatal organogenesis require dose optimization and careful evaluation of long-term outcomes in clinical trials. Intraocular ranibizumab is likely a safer alternative; however, outstanding questions remain regarding efficacy. Optimal patient outcomes rely on a combination of risk management throughout neonatal intensive care, timely diagnosis through careful ophthalmologic examinations, and treatment when indicated with laser therapy and/or anti-VEGF intravitreal injection.

Insight on the cellular and molecular basis of blood vessel formation: A specific focus on tumor targets and therapy

AbstractThe cellular and molecular switches that govern angiogenesis are considered therapeutic targets for several diseases like tumors and atherosclerosis. Thus, understanding the detailed molecular mechanisms underlying the formation of the new blood vessel is essential for developing novel therapeutic strategies. The formation of a new blood vessel (angiogenesis) is tightly regulated by balancing pro‐ and antiangiogenic molecules. Dysregulated angiogenesis contributes to the pathogenicity of several diseases, including tumors associated with uncontrolled vessel growth. Experimental and clinical studies emphasize that angiogenesis is a critical step for the transition of the tumor to a life‐threatening malignancy. In recent years, angiogenesis has been targeted as one of the primary therapeutic goals for treating tumors, and rapid progress has been made by modulating its molecular regulators. Hence, the mechanisms of how blood vessel formation occurs could provide molecular insight into future angiogenic therapy. This review summarizes briefly the molecular players of blood vessel formation comprising vasculogenesis and angiogenesis and their role in tumor progression alongside antiangiogenic therapy.

An Alpha-fetoprotein derived Peptide Suppresses Growth in Breast Cancer and Other Malignancies: A Review and Prospectus

Growth Inhibitory Peptide (GIP) is an alpha-fetoprotein (AFP) derived peptide found during human pregnancy, which gradually disappears following childbirth in both the woman and the newborn. Following a stress-induced conformational change in the AFP molecule, GIP is exposed on the protein surface from a concealed occult site on the unfolded full-length AFP. The exposed 34-amino acid GIP peptide then targets, blocks, and suppresses malignant growth in the mammalian body. In the present report, GIP has been demonstrated to inhibit cell growth in vitro in nine different types of cancers including breast, prostate, and ovarian among others. GIP can further assist in preventing blood clotting, arresting growth via the cytoplasmic growth cycle, suppressing tumor blood vessel angiogenesis, and inhibiting circulating cancer cell metastasis. In further studies, GIP has been reported to suppress cancer growth in 38 of 60 different cancer cell culture lines. The growth suppressed human breast cancer cell lines included MCF-7, T-47D, Bt-547, MDA-MB-231, MDA-MB-435, in addition to mouse mammary tumor implants and xenografts. Thus, GIP was found to suppress and inhibit cancer growth in both in vitro and in vivo preclinical studies.

Analysis of Preeclampsia in Pregnant Women Reviewing from Vascular Disorders due to Endothelial Dysfunction

Preeclampsia is a multisythemic disorder in pregnancy. Some theories reveal that PE is a result of imuune and hormonal response disorders during pregnancy. In the preeclampsia there is a endothelial dysfunction in the controlling vascular function to respond to blood composition and function disorder as a physical barrier to the exchange of fluid, ion proteins and cells from the blood through the vasculer wall. In addition, there is a decrease in angiogenesis and vasodilatation of blood vessels in response to oxygen pressure and mechanical stress like shear stress. Analyzing the incidence of preeclampsia in pregnant women in terms of vascular disorders doe to endothelial dysfunction. Design : observational, a cross sectional approach. Probability sampling using random sampling. Statistical analysis logistic regression. Data processing Hosmer and Lemeshow Test. Assumption of the amount of influence a summary model. PE incidence of pregnant woman 94 (6.15%), 53 people (56.4%) PE, 41 (43.6%) PEB.

Microvasculopathy in spinal muscular atrophy is driven by a reversible autonomous endothelial cell defect.

Spinal muscular atrophy (SMA) is a neuromuscular disorder due to degeneration of spinal cord motor neurons caused by deficiency of the ubiquitously expressed SMN protein. Here, we present a retinal vascular defect in patients, recapitulated in SMA transgenic mice, driven by failure of angiogenesis and maturation of blood vessels. Importantly, the retinal vascular phenotype was rescued by early, systemic SMN restoration therapy in SMA mice. We also demonstrate in patients an unfavorable imbalance between endothelial injury and repair, as indicated by increased circulating endothelial cell counts and decreased endothelial progenitor cell counts in blood circulation. The cellular markers of endothelial injury were associated with disease severity and improved following SMN restoration treatment in cultured endothelial cells from patients. Finally, we demonstrated autonomous defects in angiogenesis and blood vessel formation, secondary to SMN deficiency in cultured human and mouse endothelial cells, as the underlying cellular mechanism of microvascular pathology. Our cellular and vascular biomarker findings indicate microvasculopathy as a fundamental feature of SMA. Our findings provide mechanistic insights into previously described SMA microvascular complications, and highlight the functional role of SMN in the periphery, including the vascular system, where deficiency of SMN can be addressed by systemic SMN-restoring treatment.

Biomimetic injectable hydrogel based on silk fibroin/hyaluronic acid embedded with methylprednisolone for cartilage regeneration

Articular cartilage injury is characterized by limited self-repair capacity due to the shortage of blood vessels, lymphatics, and nerves. Hence, this study aims to exploit a classic injectable hydrogel platform that can restore the cartilage defects with minimally invasive surgery, which is similar to the natural extracellular microenvironment, and highly porous network for cell adhesion and proliferation. In this study, an injectable scaffold system comprised of silk fibroin (SF) and hyaluronic acid (HA) was developed to adapt the above requirements. Besides, methylprednisolone (MP) was encapsulated by SF/HA scaffold for alleviating inflammation. The SF/HA hydrogel scaffold was prepared by chemical cross-linking between the lysine residues of SF via Schiff base formation, and pore diameter of the obtained hydrogels was 100.47 ± 32.09 µm. The highly porous nature of hydrogel could further benefit the soft tissue regeneration. Compared with HA-free hydrogels, SF/HA hydrogel showed more controlled release on MP. In ovo experiment of chick embryo chorioallantoic membrane (CAM) demonstrated that SF/HA hydrogels not altered the angiogenesis and formation of blood vessels, thus making it suitable for cartilage regeneration. Furthermore, in vivo gel formation was validated in mice model, suggesting in situ gel formation of SF/HA hydrogels. More importantly, SF/HA hydrogels exhibited the controlled biodegradation. Overall, SF/HA hydrogels provide further insights to the preparation of effective scaffold for tissue regeneration and pave the way to improve the articular cartilage injury treatment.

Supercritical Impregnation of Mango Leaf Extract into PLA 3D-Printed Devices and Evaluation of Their Biocompatibility with Endothelial Cell Cultures.

The addition of natural substances with pharmacoactive properties to polymeric biomedical devices would provide beneficial regarding the assimilation of these endoprostheses when implanted into a patient’s body. The added drug would facilitate endothelization by regulating the inflammatory processes that such interventions entail, preventing contamination hazards and favoring the angiogenesis or formation of blood vessels in the tissue. The present work used mango leaf extract (MLE) obtained through pressurized ethanol for this purpose. Polylactic acid (PLA) in the form of filaments or 3D-printed disks was impregnated by means of supercritical technology with MLE for the culture essays. The release kinetics has been studied and the polymer matrices have been examined by scanning electron microscopy (SEM). The impregnated devices were subjected to in vitro culture of colony-forming endothelial cells. The influence of the different impregnation conditions used for the production of the MLE impregnated polymeric devices on the development of the cell culture was determined by fluorescence microscopy. The best results were obtained from the calcein cultures on 35 °C MLE impregnated into 3D-printed polymer disks.

Abstract 6139: GPR4 promotes the development of colitis-associated colorectal cancer in an experimental mouse model

Abstract GPR4 is a proton-sensing G protein-coupled receptor expressed in endothelial cells as well as other cell types. Endothelial cell adhesion, blood vessel permeability, leukocyte infiltration, and angiogenesis are regulated by the proinflammatory functions of GPR4. Inhibition of GPR4 ameliorates inflammatory bowel disease (IBD) in mouse models. GPR4 expression is upregulated in the intestinal tissues of IBD and colorectal cancer patients and is associated with a worse prognosis. Herein, we studied the role of GPR4 in colitis-associated colorectal cancer (CAC) by inducing CAC in GPR4 knockout (KO) and wild-type (WT) mice using azoxymethane (AOM)/dextran sulfate sodium (DSS). The severity of CAC development was higher in WT mice than GPR4 KO mice when treated with AOM/DSS. Blood vessel density was significantly higher within the tumors of WT mouse colons compared to GPR4 KO mice. GPR4 KO tumors showed a significant increase in tumor necrosis in comparison to WT tumors. Fecal blood/diarrhea score, colon shortening, and mesenteric lymph node size were aggravated in WT mice compared to GPR4 KO mice treated with AOM/DSS. Our data demonstrate that GPR4 increases intestinal inflammation and angiogenesis, enhancing tumor development in the CAC mouse model, suggesting that GPR4 inhibition may reduce the risk of developing colitis-associated colorectal cancer. Citation Format: Mona A. Marie, Edward J. Sanderlin, Alexander Hoffman, Li V. Yang. GPR4 promotes the development of colitis-associated colorectal cancer in an experimental mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6139.

Reactive Oxygen Species are Essential for Placental Angiogenesis During Early Gestation.

Background Preeclampsia (PE) is associated with insufficient placental perfusion attributed to maldevelopment of the placental vasculature. Reactive oxygen species (ROS) are implicated in angiogenesis, but their regulatory effects and mechanisms in placental vascular development remain unclear. Methods Placental oxidative stress was determined throughout gestation by measuring 4-hydroxynonenal (4HNE) and malondialdehyde (MDA). The antioxidant MitoQ was administered to pregnant mice from GDs 7.5 to 11.5; placental morphology and angiogenesis pathways were examined on GDs 11.5 and 18.5. Moreover, we established a mouse mFlt-1-induced PE model and assessed blood pressure, urine protein levels, and placental vascular development on GDs 11.5 and 18.5. Human umbilical vein endothelial cells (HUVECs) were treated with various H2O2 concentrations to evaluate cell viability, intracellular ROS levels, and tube formation capability. MitoQ, an AKT inhibitor and an ERK1/2 inhibitor were applied to validate the ROS-mediated mechanism regulating placental angiogenesis. Results First-trimester placentas presented significantly higher MDA and 4HNE levels. MitoQ significantly reduced the blood vessel density and angiogenesis pathway activity in the placenta on GDs 11.5 and 18.5. Serum sFlt-1 levels were elevated, and we observed poor placental angiogenesis and PE-like symptoms in cases with mFlt-1 overexpression. Moderate H2O2 treatment promoted HUVEC proliferation and angiogenesis, whereas these improvements were abolished by MitoQ, AKT inhibitor, or ERK1/2 inhibitor treatment. Conclusions Moderate ROS levels are essential for placental angiogenesis; diminishing ROS with potent antioxidants during placentation decreases placental angiogenesis and increases PE risk. Therefore, antioxidant therapy should be considered carefully for normal pregnant women during early gestation.

Retinal Pathophysiological Evaluation in a Rat Model.

A posterior segment eye disease like diabetic retinopathy alters the physiology of the retina. Diabetic retinopathy is characterized by a retinal detachment, breakdown of the blood-retinal barrier (BRB), and retinal angiogenesis. An in vivo rat model is a valuable experimental tool to examine the changes in the structure and function of the retina. We propose three different experimental techniques in the rat model to identify morphological changes of retinal cells, retinal vasculature, and compromised BRB. Retinal histology is used to study the morphology of various retinal cells. Also, quantitative measurement is performed by retinal cell count and thickness measurement of different retinal layers. A BRB breakdown assay is used to determine the leakage of extraocular proteins from the plasma to vitreous tissue due to the breakdown of BRB. Fluorescence angiography is used to study angiogenesis and leakage of blood vessels by visualizing retinal vasculature using FITC-dextran dye.

The Role of Amino Acids in Endothelial Biology and Function.

The vascular endothelium acts as an important component of the vascular system. It is a barrier between the blood and vessel wall. It plays an important role in regulating blood vessel tone, permeability, angiogenesis, and platelet functions. Several studies have shown that amino acids (AA) are key regulators in maintaining vascular homeostasis by modulating endothelial cell (EC) proliferation, migration, survival, and function. This review summarizes the metabolic and signaling pathways of AAs in ECs and discusses the importance of AA homeostasis in the functioning of ECs and vascular homeostasis. It also discusses the challenges in understanding the role of AA in the development of cardiovascular pathophysiology and possible directions for future research.

ETS-Related Gene Activation Preserves Adherens Junctions and Permeability in Microvascular Endothelial Cells.

ERG (ETS-related gene) is a member of the ETS (Erythroblast-transformation specific) family of transcription factors abundantly present in vascular endothelial cells. Recent studies demonstrate that ERG has important roles in blood vessel stability and angiogenesis. However, it is unclear how ERG is potentially involved in microvascular barrier functions and permeability. A wide variety of diseases and clinical conditions including trauma-hemorrhagic shock and burn injury are associated with microvascular dysfunctions, which causes excessive microvascular permeability, tissue edema and eventually, multiple organ dysfunction and death. The main purpose of this study was to determine the specific role of ERG in regulating microvascular permeability in human lung microvascular endothelial cells (HLMEC) and to evaluate if exogenous ERG will protect the barrier. The HLMECs were grown on Transwell inserts as monolayers and were transfected with ERG CRISPR/cas9 knockdown plasmid, ERG CRISPR activation plasmid, recombinant ERG protein or their respective controls. Recombinant vascular endothelial growth factor (VEGF) was used as an inducer of permeability for evaluating the effect of ERG activation on permeability. Changes in barrier integrity and permeability were studied using monolayer permeability assay and immunofluorescence of adherens junction proteins (VE-cadherin and β-catenin) respectively. CRISPR/cas9-based ERG knockdown as well as VEGF treatment induced monolayer hyperpermeability, VE-cadherin, and β-catenin junctional relocation and cytoskeletal F-actin stress fiber formation. CRISPR based ERG activation and recombinant ERG transfection attenuated VEGF-induced monolayer hyperpermeability. ERG activation preserved the adherens junctions and cytoskeleton. These results demonstrate that ERG is a potent regulator of barrier integrity and permeability in human lung microvascular endothelial cells and endogenously or exogenously enhancing ERG provides protection against barrier dysfunction and hyperpermeability.

Piezo1 mediates endothelial atherogenic inflammatory responses via regulation of YAP/TAZ activation

The vascular endothelium plays a key role in the pathobiology of atherosclerotic cardiovascular disease. Endothelial cell Piezo1 mediates blood vessel formation, angiogenesis and regulation of blood pressure. However, changes of Piezo1 expression in atherosclerosis (AS) and the role of Piezo1 in the progression of atherosclerotic diseases remains obscure. Thus, the current study is to elucidate the role and mechanism of which Piezo1 mediates vascular inflammation in atherosclerotic mice and vascular endothelial inflammation induced by oxidized low density lipoprotein (ox-LDL) in vitro. Here, we have shown that the expression of Piezo1 was significantly increased in the stenotic carotid artery of ApoE-/- mice fed by high-fat diet (HFD). Pharmacological inhibition of Piezo1 (GsMTx-4) attenuated plaque formation, decreased the level of inflammation related factors (JNK, TNF-α, NF-κB, VCAM-1) of carotid plaque in atherosclerotic mice. Meanwhile, ox-LDL also upregulates Piezo1 and inflammation proteins (NF-κB, JNK and TNF-α) in endothelium cells (ECs). YAP/TAZ is activated accompanied by the enhanced Piezo1 activity in ECs induced by ox-LDL. Interference by siRNA of Piezo1 abolished the expression of YAP/TAZ and inflammation proteins (JNK, NF-κB and TNF-α). In addition, Ca2+ influx in ECs induced by ox-LDL was increased than control group, Piezo1 siRNA can reduce the calcium content. Piezo1 agonist Yoda1 increased Ca2+ influx and promote YAP nucleus translocation in ECs, genetic deletion of Piezo1 reversed it. Our results indicate that Piezo1 could mediate endothelial atherogenic inflammatory responses via regulation of YAP/TAZ activation and nuclear localization. Piezo1 may be a potential therapeutic target for atherosclerotic diseases in the future.