Endothelial Adhesion Molecule Expression Research Articles

Angiogenic potential in periodontal stem cells from upper and lower jaw: A pilot study.

Teeth and supporting oral tissues are attractive and accessible sources of stem cells. Periodontal ligament stem cells (PDLSC) are readily isolated from extracted third molars, and exhibit the ability to self-renew and differentiate into multiple mesodermal cell fates. Clinical experience suggests that the exact location of periodontal defects affects the oral bone remodeling and wound healing. Compared to the mandible, the maxilla heals quicker and more efficiently. Angiogenesis is key in tissue regeneration including dental tissues, yet few studies focus on the angiogenic potential of PDLSC, none of which considered the differences between upper and lower jaw PDLSC (u-PDLSC and l-PDLSC, respectively). Here we studied the angiogenic potential of u-PDLSC and l-PDLSC and compared the results to well-established mesenchymal stem cells (MSC). Cells were characterized in terms of surface markers, proliferation, and vascular endothelial growth factor (VEGF) secretion, and angiogenic assays were performed. Newly formed capillaries were stained with CD31, and their expression of platelet endothelial cell adhesion molecule (PECAM-1), angiopoietin 2 (ANGPT2), and vascular endothelial growth factor receptor 1 and 2 (VEGFR-1, VEGFR-2) were measured. Periodontal stem cells from the upper jaw showed a higher proliferation capacity, secreted more VEGF, and formed capillary networks faster and denser than l-PDLSC. Gene expression of angiogenesis-related genes was significantly higher in u-PDLSC than in l-PDLSC or MSC, given that culture conditions were suitable. The oral cavity is a valuable source of stem cells, particularly PDLSC, which are promising for oral tissue engineering due to their robust growth, lifelong accessibility, low immunogenicity, and strong differentiation potential. Notably, u-PDLSC exhibit higher VEGF secretion and accelerate capillary formation compared to l-PDLSC or MSC. This study suggests a potential molecular mechanism in capillary formation, emphasizing the significance of precise location isolation of PDLSC.

Endothelial PTP1B Deletion Promotes VWF Exocytosis and Venous Thromboinflammation.

Endothelial activation promotes the release of procoagulant extracellular vesicles and inflammatory mediators from specialized storage granules. Endothelial membrane exocytosis is controlled by phosphorylation. We hypothesized that the absence of PTP1B (protein tyrosine phosphatase 1B) in endothelial cells promotes venous thromboinflammation by triggering endothelial membrane fusion and exocytosis. Mice with inducible endothelial deletion of PTP1B (End.PTP1B-KO) underwent inferior vena cava ligation to induce stenosis and venous thrombosis. Primary endothelial cells from transgenic mice and human umbilical vein endothelial cells were used for mechanistic studies. Vascular ultrasound and histology showed significantly larger venous thrombi containing higher numbers of Ly6G (lymphocyte antigen 6 family member G)-positive neutrophils in mice with endothelial PTP1B deletion, and intravital microscopy confirmed the more pronounced neutrophil recruitment following inferior vena cava ligation. RT2 PCR profiler array and immunocytochemistry analysis revealed increased endothelial activation and adhesion molecule expression in primary End.PTP1B-KO endothelial cells, including CD62P (P-selectin) and VWF (von Willebrand factor). Pretreatment with the NF-κB (nuclear factor kappa B) kinase inhibitor BAY11-7082, antibodies neutralizing CD162 (P-selectin glycoprotein ligand-1) or VWF, or arginylglycylaspartic acid integrin-blocking peptides abolished the neutrophil adhesion to End.PTP1B-KO endothelial cells in vitro. Circulating levels of annexin V+ procoagulant endothelial CD62E+ (E-selectin) and neutrophil (Ly6G+) extracellular vesicles were also elevated in End.PTP1B-KO mice after inferior vena cava ligation. Higher plasma MPO (myeloperoxidase) and Cit-H3 (citrullinated histone-3) levels and neutrophil elastase activity indicated neutrophil activation and extracellular trap formation. Infusion of End.PTP1B-KO extracellular vesicles into C57BL/6J wild-type mice most prominently enhanced the recruitment of endogenous neutrophils, and this response was blunted in VWF-deficient mice or by VWF-blocking antibodies. Reduced PTP1B binding and tyrosine dephosphorylation of SNAP23 (synaptosome-associated protein 23) resulting in increased VWF exocytosis and neutrophil adhesion were identified as mechanisms, all of which could be restored by NF-κB kinase inhibition using BAY11-7082. Our findings show that endothelial PTP1B deletion promotes venous thromboinflammation by enhancing SNAP23 phosphorylation, endothelial VWF exocytosis, and neutrophil recruitment.

The role and mechanism of RIPK1 in vascular endothelial dysfunction in chronic kidney disease.

Endothelial dysfunction is common in patients with chronic kidney disease (CKD) and cardiovascular events, but the mechanism is unclear. In our study, we found elevated levels of RIPK1 in patients with CKD and cardiovascular events through bioinformation analysis. Elevated RIPK1 levels were found in serum samples of CKD patients and were associated with vascular endothelial dysfunction and renal function. We constructed the five of six nephrectomy of CKD mice model, finding that RIPK1 expressions were elevated in abdominal aorta endothelial cells. After RIPK1 inhibition and overexpression, it was found that RIPK1 could regulate the expression of endothelial nitric oxide synthase (eNOS) and cell adhesion molecule 1 (ICAM-1), and activation of inflammatory responses and endoplasmic reticulum (ER) stress. In addition, uremic toxin induced abnormal expression of RIPK1 invitro. We observed RIPK1-mediating endothelial dysfunction and inflammation responses by ER stress pathways through gain and loss of function. In order to explore the specific mechanism, we conducted co-immunoprecipitation and expression regulation of RIPK1 and IKK, finding that RIPK1 formed complex with IKK and regulated IKK expression. In conclusion, we demonstrated that RIPK1 levels were closely associated with vascular endothelial dysfunction in patients with CKD. With uremic toxins, RIPK1 expression was elevated, which led to the activation of inflammation through the ER stress pathway, resulting in vascular endothelial injury. Besides, activation of RIPK1-IKK-NF-κB axis was a key driver of endothelial dysfunction in CKD. Our study provides a new perspective for the study of cardiovascular events in CKD.

A ring N(CH3)2-based derivative of resveratrol inhibits pulmonary vascular remodeling in hypoxia pulmonary hypertension

Pulmonary artery smooth muscle cells (PASMCs) phenotypic switching and pulmonary artery endothelial cells (PAECs) endothelial-mesenchymal transition (EndMT) are important in promoting pulmonary hypertension (PH)-pulmonary vascular remodeling (PVR). Resveratrol can efficiently inhibit the proliferation of PASMCs, but its application is limited due to its low bioavailability and solubility. In this study, we modified resveratrol to assess the role of A ring N(CH3)2-based derivatives of resveratrol (Res4) in PVR-PASMCs phenotypic switching and PVR-PAECs EndMT. Chemical methods were used for the preparation of Res4; NMRS and HPLC were used to authenticate Res4. Mice developed PVR after 4 weeks of hypoxia (10% O2). Res4 (50 mg/kg/d) attenuated right ventricular systolic pressure, right ventricular hypertrophy, and PVR. PASMCs developed phenotypic switching and PAECs developed EndMT after 2 days of hypoxia (3% O2). Res4 (10 μM) could inhibit PASMCs and PAECs viability. Res4 could decrease proliferating cell nuclear antigen (PCNA) and osteopontin (OPN) expression, and increase α-smooth muscle actin (α-SMA) and vimentin expression in PASMCs. It could also decrease PCNA, α-SMA, vimentin expression and increase platelet endothelial cell adhesion molecule (CD31) expression in PAECs. Notably, Res4 inhibited the phosphorylation levels of mitogen-activated protein kinase kinase (MEK), extracellular signal-regulated protein kinase (ERK), Jun-N-terminal kinase (JNK), and p38 kinase in hypoxia-treated PASMCs and PAECs, indicating MAPK pathway may be involved in Res4-induced inhibition of PASMCs phenotypic switching and PAECs EndMT. Our data demonstrated that Res4 exerts antiproliferative effects by regulating PASMCs phenotypic switching and PAECs EndMT. Res4 may be potentially used as a drug against PH-PVR.

CERCAM is a prognostic biomarker associated with immune infiltration of macrophage M2 polarization in head and neck squamous carcinoma

PurposeThis study aimed to investigate the relevance of cerebral endothelial cell adhesion molecule (CERCAM) expression to head and neck squamous cell carcinoma (HNSCC) prognosis and immune infiltration by macrophage M2 polarization.MethodsTimer, UALCAN and HPA databases was used to analyze the differences in mRNA and protein levels of CERCAM expression in HNSCC. The Timer database was also applied to analyze the correlation between CERCAM in HNSCC and immune infiltration. TCGA-HNSCC database was applied to analyze the correlation between CERCAM expression levels and clinicopathological features, and its diagnostic and prognostic value in HNSCC was also assessed. The cBioPortal and MethSurv databases were then applied to analyze the genetic variation and methylation status of CERCAM. In vitro cellular assays were performed to provide evidence that CERCAM promotes malignant biological behavior of tumors and promotes macrophage M2 polarization in tumors. Finally, underlying pathophysiological mechanisms of CERCAM involvement in the development of HNSCC were predicted using a bioinformatics approach.ResultsCERCAM is significantly overexpressed in HNSCC and correlates with poor prognostic levels and has good performance in predicting survival status in HNSCC patients. Cox regression analysis indicates that CERCAM expression levels are independent risk factors for predicting OS, DSS, and PFI. CERCAM promotes tumor malignant biological behavior and promotes macrophage M2 polarization immune infiltration in HNSCC. In addition, CERCAM promotes tumor cell adhesion in head and neck squamous carcinoma and promotes tumor progression through several oncogenic signaling pathways.ConclusionCERCAM may serve as a new diagnostic and prognostic biomarker in HNSCC and is a promising therapeutic target for HNSCC.

Epigenetic Mechanisms in Vascular Inflammation: Modulation of Endothelial Adhesion Molecules and Endothelium-Leukocyte Adhesion.

The endothelium, an essential component of the vascular system, plays a critical role in the inflammatory response. Under pro-inflammatory stimuli, endothelial cells undergo activation and dysfunction, leading to the release of inflammatory mediators and upregulation of cell adhesion molecules. These changes facilitate the adhesion, rolling, and transmigration of leukocytes into the subendothelial space. Emerging evidence suggests that epigenetic mechanisms, including nucleic acid methylation, post-translational histone modifications, and non-coding RNA, contribute significantly to the regulation of vascular inflammation and expression of cell adhesion molecules. Understanding the epigenetic molecular signatures that govern these processes may provide new insights into the development of therapeutic strategies to combat vascular inflammation and associated diseases. This review aims to summarize the current knowledge on the epigenetic mechanisms involved in modulating the intricate processes underlying vascular inflammation, with a specific focus on the expression of endothelial adhesion molecules and endothelium-leukocyte adhesion.

Endothelial RIPK1 protects artery bypass graft against arteriosclerosis by regulating SMC growth.

RIPK1 is crucial in the inflammatory response. The process of vascular graft remodeling is also involved in endothelial inflammation, which can influence the behavior of smooth muscle cells. However, the role of endothelial RIPK1 in arterial bypass grafts remains unknown. Here, we established an arterial isograft mouse model in wild-type and endothelial RIPK1 conditional knockout mice. Progressive vascular remodeling and neointima formation occurred in the graft artery, showing SMC accumulation together with endothelial inflammatory adhesion molecule and cytokine expression. Endothelial RIPK1 knockout exacerbated graft stenosis by increasing secretion of N-Shh. Mechanistically, RIPK1 directly phosphorylated EEF1AKMT3 at Ser26, inhibiting its methyltransferase activity and global protein synthesis, which further attenuated N-Shh translation and secretion. Consistently, treatment with the Hedgehog pathway inhibitor GDC0449 markedly alleviated RIPK1 knockout-induced graft stenosis. Our results demonstrated that endothelial RIPK1 played a protective role in arterial bypass graft vascular remodeling, highlighting that targeting Hedgehog pathway may be an attractive strategy for graft failure in the future.

Composite Hydrogel Dressings with Enhanced Mechanical Properties and Anti-Inflammatory Ability for Effectively Promoting Wound Repair.

Hydrogel dressings have been used as a crucial method to keep the wound wet and hasten the healing process. Due to safety concerns regarding the gel components, low mechanical adhesiveness, and unsatisfactory anti-inflammatory capacity qualities for practical uses in vivo, leading to the clinical translation of wound dressings is still difficult. A type of composite hydrogel (acrylamide/polyethylene glycol diacrylate/tannic acid, ie, AM/PEGDA/TA) by double bond crosslinking, Schiff base, and hydrogen bond interaction is proposed. The mechanical characteristics, adhesiveness, and biocompatibility of the hydrogel system were all thoroughly examined. Additionally, a full-thickness cutaneous wound model was employed to assess the in vivo wound healing capacity of resulting hydrogel dressings. Benefiting the mechanism of multiple crosslinking, the designed composite hydrogels showed significant mechanical strength, outstanding adhesive capability, and good cytocompatibility. Moreover, the hydrogel system also had excellent shape adaptability, and they can be perfectly integrated into the irregularly shaped wounds through a fast in situ forming approach. Additional in vivo tests supported the findings that the full-thickness wound treated with the composite hydrogels showed quicker epithelial tissue regeneration, fewer inflammatory cells, more collagen deposition, and greater levels of platelet endothelial cell adhesion molecule (CD31) expression. These above results might offer a practical and affordable product or method of skin wound therapy in a medical context.

Evaluation of the healing potential of Nile tilapia skin collagen in traumatic oral ulcers in male rats

ObjectiveTo evaluate the healing potential of Nile tilapia skin collagen using a rat model with experimentally induced traumatic oral ulcers. DesignMale Wistar rats were segregated into three experimental groups (n = 8/group/euthanasia day). Ulcers were induced using a dermatological punch on the left buccal mucosa. The rats were then euthanized on days 1, 5, 10, 15, and 20 (ntotal=120 rats). Each group received topical treatment, 2x/day, with 1 % Nile tilapia skin collagen orabase (experimental group), only orabase (negative control), or Oncilom-A® orabase (positive control). Ulcer area, closure percentage, and body mass variation were measured. Slides were prepared for histological analysis, which included Picrosirius red staining (collagen analysis), and immunohistochemistry (platelet endothelial cell adhesion molecule, alpha-smooth muscle actin, and transforming growth factor-beta). ResultsOn day 15, the experimental and positive control groups displayed smaller ulcer areas, a higher percentage of closure, complete re-epithelialization, superior histological repair scores, and a reduced count of polymorphonuclear cells in comparison to the negative control group (p < 0.05). Additionally, the experimental group exhibited an increased number of blood vessels, total collagen (types I and III) and expression of platelet endothelial cell adhesion molecule, alpha-smooth muscle actin, and transforming growth factor-beta relative to the negative and positive control groups (p < 0.05). By day 20, the experimental group showed a more significant weight gain compared to the other groups (p < 0.0001). ConclusionsNile tilapia skin collagen orabase optimizes the healing of traumatic ulcers by stimulating re-epithelialization, angiogenesis, and collagenesis. Transforming growth factor-beta plays a significant role in this process.

Abstract P2179: Endothelial-derived Extracellular Vesicles Communicate With Cardiomyocytes To Elicit Cancer Therapy-related Cardiac Dysfunction

Background: Treatment with the anthracycline, epirubicin, can result in cancer-therapy related cardiac dysfunction (CTRCD), a leading cause of non-malignant mortality in cancer survivors. Endothelial cells (ECs) lining the blood vessels are the first point of contact of epirubicin and secrete factors that are pivotal in regulating cardiac function. Of these factors, extracellular vesicles (EVs) are known to mediate intercellular communication. It remains unknown whether and how EC-EVs affect cardiomyocyte function in the context of CTRCD. Hypothesis: We hypothesize that epirubicin exposure leads to altered EC-EV cargo which mediates cardiomyocyte dysfunction. Methods: Human umbilical vein endothelial cells (HUVEC) were exposed to the peak and trough concentrations of epirubicin and endothelial function was assessed. EC-EVs were isolated via ultracentrifugation and EV size and concentration were measured through nanoparticle tracking analysis. The protein content of EC-EVs was determined using liquid chromatography with tandem mass spectrometry. Pluripotent stem cell-derived cardiomyocytes (iPSC-CM) were exposed to physiological concentrations of EVs (1x1010 particles/mL) and contractility was assessed in real-time. Results: Epirubicin exposure increased endothelial leak, apoptosis, and adhesion molecule expression. We observed an increase in size and concentration of EC-EVs and proteomic analysis revealed altered EV cargo including reduced cardiomyocyte protective factors, CNP and eNOS in EVs from epirubicin treated HUVEC in comparison to control. Treatment of iPSC-cardiomyocytes with EVs from epirubicin treated HUVECs resulted in reduced contractility compared to EVs from healthy ECs. Cleavage of EC-EV surface proteins via proteinase K abrogated the effects of EC-EVs on iPSC-cardiomyocytes. Cardiomyocyte-specific pathways targeted by EC-EVs from epirubicin- compared to control-treated cells are currently on-going. Conclusion: We demonstrate that epirubicin treatment leads to endothelial dysfunction and altered release of EVs capable of mediating cardiomyocyte dysfunction. Our results show the potential role of EC-EVs in CTRCD pathogenesis and highlight their influence on cardiomyocyte function.

Regulation of tumor angiogenesis by the crosstalk between innate immunity and endothelial cells.

Endothelial cells and immune cells are major regulators of cancer progression and prognosis. Endothelial cell proliferation and angiogenesis are required for providing nutrients and oxygen to the nascent tumor and infiltration of immune cells to the tumor is dependent on endothelial cell activation. Myeloid cells and innate lymphocytes have an important role in shaping the tumor microenvironment by crosstalking with cancer cells and structural cells, including endothelial cells. Innate immune cells can modulate the activation and functions of tumor endothelial cells, and, in turn, endothelial cell expression of adhesion molecules can affect immune cell extravasation. However, the mechanisms underlying this bidirectional crosstalk are not fully understood. In this review, we will provide an overview of the current knowledge on the pathways regulating the crosstalk between innate immune cells and endothelial cells during tumor progression and discuss their potential contribution to the development of novel anti-tumor therapeutic approaches.

Antigen loaded monocytes prime CD4+ T cell responses through Notch2 dependent cDC2

Abstract Cellular vaccines, primarily monocyte-derived dendritic cells (MoDC), have recently been realized as therapeutic cancer vaccines with modest clinical efficacy. Understanding the mechanism by which these vaccines lead to antigen presentation is key to improving their potency. A significant advancement was the discovery that MoDC vaccines do not directly present antigen, but instead rely on endogenous dendritic cells for their antigen presenting cell (APC) function. Subsequent research has also demonstrated that primary monocytes can be loaded with antigen and used as cellular vaccines, outperforming MoDC vaccines in mouse models of melanoma and glioblastoma. In this study, we characterized how monocyte vaccines generate CD4+ T cell responses. We utilized the CD11c-Cre RBPJfl/flmouse model, which lack a subset of Notch2 dependent cDC2 characterized by expression of Endothelial cell-selective adhesion molecule (ESAM hi). We demonstrate that the ESAM hicDC2 subset is required for effective CD4+ OT-II T cell priming after vaccination with ovalbumin (OVA) loaded monocytes. Interestingly, depletion of the ESAM hiDC population does not affect monocyte vaccine-induced CD8+ T cell priming, a process previously shown to be dependent on cDC1. This indicates that monocyte vaccines generate T cell responses by independently transferring antigen to both ESAM hiand CD8+ DCs, leveraging their APC function to prime CD4+ and CD8+ T cell responses, respectively. This work furthers the mechanistic understanding of monocyte vaccines, and will inform the design of future monocyte vaccines as they enter clinical trials as therapeutic cancer vaccines. Supported by NCI P50 CA 190991 and funding from the Stead Scholarship Program of the Duke University Department of Medicine.

PIMT is a novel and potent suppressor of endothelial activation.

Proinflammatory agonists provoke the expression of cell surface adhesion molecules on endothelium in order to facilitate leukocyte infiltration into tissues. Rigorous control over this process is important to prevent unwanted inflammation and organ damage. Protein L-isoaspartyl O-methyltransferase (PIMT) converts isoaspartyl residues to conventional methylated forms in cells undergoing stress-induced protein damage. The purpose of this study was to determine the role of PIMT in vascular homeostasis. PIMT is abundantly expressed in mouse lung endothelium and PIMT deficiency in mice exacerbated pulmonary inflammation and vascular leakage to LPS(lipopolysaccharide). Furthermore, we found that PIMT inhibited LPS-induced toll-like receptor signaling through its interaction with TNF receptor-associated factor 6 (TRAF6) and its ability to methylate asparagine residues in the coiled-coil domain. This interaction was found to inhibit TRAF6 oligomerization and autoubiquitination, which prevented NF-κB transactivation and subsequent expression of endothelial adhesion molecules. Separately, PIMT also suppressed ICAM-1 expression by inhibiting its N-glycosylation, causing effects on protein stability that ultimately translated into reduced EC(endothelial cell)-leukocyte interactions. Our study has identified PIMT as a novel and potent suppressor of endothelial activation. Taken together, these findings suggest that therapeutic targeting of PIMT may be effective in limiting organ injury in inflammatory vascular diseases.

5610845 A PHASE 1 STUDY OF CSL888 (HEMOPEXIN) IN ADULT PATIENTS WITH SICKLE CELL DISEASE

Background: Episodes of vaso-occlusive crisis (VOC) are the primary reason for hospitalization among patients with sickle cell disease (SCD). The release of heme from the breakdown of damaged red blood cells is thought to play an important role in contributing to vaso-occlusion in SCD. Free heme promotes activation of endothelium, expression of endothelial cell adhesion molecules and activation of blood cells (neutrophils, monocytes, and platelets) which “stick” to the blood vessel walls. The net result is blockage of blood circulation, resulting in the characteristic pain of VOC. Hemopexin is a 60 kilodalton (kDa) plasma glycoprotein that is mainly expressed in the liver and belongs to the family of acute-phase proteins whose synthesis is induced after an inflammatory event. Hemopexin binds extracellular heme with the highest known affinity (KD < 1pM) of all plasma proteins. In patients with SCD, hemopexin levels are significantly reduced (approximately 85%) compared to healthy controls due to increased consumption. CSL889 is human plasma-derived hemopexin. It is hypothesized that pharmacological administration of CSL889 may decrease heme toxicity, restore normal blood circulation and therefore have beneficial effects in the management of acute VOC in SCD patients. Translation to the clinic is supported by studies performed in vitro demonstrating protection of heme-mediated endothelial cell damage and in vivo using the Townes mouse model of SCD, in which hemopexin was shown ameliorate vaso-occlusion following hemoglobin or hypoxia/reperfusion challenges (Gentinetta et al. 2022). Preclinical repeat dose toxicity studies in animals have evidenced favorable tolerability up to the highest dose level tested. Methods: We describe the design of a Phase 1, first in human, multicenter, open-label study to evaluate the safety, tolerability, and pharmacokinetics (PK) of CSL889 in adult patients with SCD following single intravenous (IV) doses of CSL889 [NCT04285827]. The study will comprise 2 parts. Part A will include patients with SCD in their usual health (not in VOC) who will receive a single dose of CSL889 at one of up to 6 different dose levels. In Part B, patients with SCD who present in VOC requiring intravenous (IV) opioid injections and admission to hospital for further management, will receive a single dose of CSL889 at a level that has been shown to be safe and tolerable in Part A within 36 hours of in-patient admission. All subjects will be followed up for 32 days post-infusion of CSL889. The range of doses to be studied is based on a translational PK model based on data derived from the study of CSL889 in the Townes mouse model of SCD. Results: The primary objective is to determine the safety and tolerability of single doses of CSL889 given to patients with SCD both without (Part A) and with (Part B) active VOC. The secondary objectives are to determine the PK and immunogenicity of CSL889. Exploratory objectives are to determine changes in biomarkers of target engagement (including changes in cell-free heme) and pharmacodynamic biomarkers related to the mechanism of action. Change in pain scores (as measured by Numeric Rating Scale [NRS]) will be additionally evaluated in Part B. Conclusions: Enrollment is in progress. No serious adverse events considered related to the administration of CSL889 have been reported as of 01-Sep-2022. Disclosures: F Wilson, J Jochems, L Lindqvist, K Jung,T Gentinetta, S Costin and GJ Kato are employed by CSL Reference 1. Gentinetta et al, J Clin Med 2022, 11:630

The angiopoietin receptor Tie2 is atheroprotective in arterial endothelium

Leukocytes and resident cells in the arterial wall contribute to atherosclerosis, especially at sites of disturbed blood flow. Expression of endothelial Tie1 receptor tyrosine kinase is enhanced at these sites, and attenuation of its expression reduces atherosclerotic burden and decreases inflammation. However, Tie2 tyrosine kinase function in atherosclerosis is unknown. Here we provide genetic evidence from humans and from an atherosclerotic mouse model to show that TIE2 is associated with protection from coronary artery disease. We show that deletion of Tie2, or both Tie2 and Tie1, in the arterial endothelium promotes atherosclerosis by increasing Foxo1 nuclear localization, endothelial adhesion molecule expression and accumulation of immune cells. We also show that Tie2 is expressed in a subset of aortic fibroblasts, and its silencing in these cells increases expression of inflammation-related genes. Our findings indicate that unlike Tie1, the Tie2 receptor functions as the dominant endothelial angiopoietin receptor that protects from atherosclerosis.

Protective mechanism of salvianolic acid B on blood vessels

Salvianolic acid B(Sal B) is the main water-soluble component of Salvia miltiorrhiza Bunge. Studies have found that Sal B has a good protective effect on blood vessels. Sal B can protect endothelial cells by anti-oxidative stress, inducing autophagy, inhibiting endoplasmic reticulum stress(ERS), inhibiting endothelial inflammation and adhesion molecule expression, inhibiting endothelial cell permeability, anti-thrombosis, and other ways. In addition, Sal B can alleviate endothelial cell damage caused by high glucose(HG). For vascular smooth muscle cell(VSMC), Sal B can reduce the synthesis and secretion of inflammatory factors by inhibiting cyclooxygenase. It can also play a vasodilatory role by inhibiting Ca~(2+) influx. In addition, Sal B can inhibit VSMC proliferation and migration, thereby alleviating vascular stenosis. Sal B also inhibits lipid deposition in the subendothelium, inhibits macrophage conversion to foam cells, and reduces macrophage apoptosis, thereby reducing the volume of subendothelial lipid plaques. For some atherosclerosis(AS) complications, such as peripheral artery disease(PAD), Sal B can promote angiogenesis, thereby improving ischemia. It should be pointed out that the conclusions obtained from different experiments are not completely consistent, which needs further research. In addition, previous pharmacokinetics showed that Sal B was poorly absorbed by oral administration, and it was unstable in the stomach, with a large first-pass effect in the liver. Sal B had fast distribution and metabolism in vivo and short drug action time. These affect the bioavailability and biological effects of Sal B, and the development of clinically valuable Sal B non-injectable delivery systems remains a great challenge.

The Effects of Pregnancy on the Pulmonary Immune Response in a Mouse Model of LPS-Induced Acute Lung Injury.

This study evaluated the effect of pregnancy on the pulmonary innate immune response in a mouse model of acute lung injury (ALI) using nebulized lipopolysaccharide (LPS). Pregnant (day 14) C57BL/6NCRL mice and nonpregnant controls received nebulized LPS for 15 minutes. Twenty-four hours later, mice were euthanized for tissue harvest. Analysis included blood and bronchoalveolar lavage fluid (BALF) differential cell counts, whole-lung inflammatory cytokine transcription levels by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), and whole-lung vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and BALF albumin by western blot. Mature bone marrow neutrophils from uninjured pregnant and nonpregnant mice were examined for chemotactic response using a Boyden chamber and for cytokine response to LPS by RT-qPCR. In LPS-induced ALI, pregnant mice had higher BALF total cell (p < 0.001) and neutrophil counts (p < 0.001) as well as higher peripheral blood neutrophils (p < 0.01) than nonpregnant mice, but a similar increase (as compared with unexposed mice) in airspace albumin levels. Whole-lung expression of interleukin 6, tumor necrosis factor-α (TNF-α), and keratinocyte chemoattractant (CXCL1) was also similar. In vitro, marrow-derived neutrophils from pregnant and nonpregnant mice had similar chemotaxis to CXCL1 and N-formylmethionine-leucyl-phenylalanine, but neutrophils from pregnant mice expressed lower levels of TNF (p < 0.001) and CXCL1 (p < 0.01) after LPS stimulation. In uninjured mice, VCAM-1 was higher in lungs from pregnant versus nonpregnant mice (p < 0.05). In this model, pregnancy is associated with an augmented lung neutrophil response to ALI without increased capillary leak or whole-lung cytokine levels relative to the nonpregnant state. This may stem from increased peripheral blood neutrophil response and intrinsically increased expression of pulmonary vascular endothelial adhesion molecules. Differences in lung innate cell homeostasis may affect the response to inflammatory stimuli and explain severe lung disease in respiratory infection during pregnancy. · Inhalation of LPS in midgestation versus virgin mice is associated with increased neutrophilia.. · This occurs without a comparative increase in cytokine expression.. · This may be explained by pregnancy-enhanced pre-exposure expression of VCAM-1 and ICAM-1..

The role of oxylipins in NSAID-exacerbated respiratory disease (N-ERD).

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) is characterized by nasal polyp formation, adult-onset asthma, and hypersensitivity to all cyclooxygenase-1 (COX-1) inhibitors. Oxygenated lipids are collectively known as oxylipins and are polyunsaturated fatty acids (PUFA) oxidation products. The most extensively researched oxylipins being the eicosanoids formed from arachidonic acid (AA). There are four major classes of eicosanoids including leukotrienes, prostaglandins, thromboxanes, and lipoxins. In N-ERD, the underlying inflammatory process of the upper and lower respiratory systems begins and occurs independently of NSAID consumption and is due to the overproduction of cysteinyl leukotrienes. Leukotriene mediators all induce edema, bronchoconstriction, and airway mucous secretion. Thromboxane A2 is a potent bronchoconstrictor and induces endothelial adhesion molecule expression. Elevated Prostaglandin D2 metabolites lead to vasoconstriction, additionally impaired up-regulation of prostaglandin E2 leads to symptoms seen in N-ERD as it is essential for maintaining homeostasis of inflammatory responses in the airway and has bronchoprotective and anti-inflammatory effects. A characteristic feature of N-ERD is diminished lipoxin levels, this decreased capacity to form endogenous mediators with anti-inflammatory properties could facilitate local inflammatory response and expose bronchial smooth muscle to relatively unopposed actions of broncho-constricting substances. Treatment options, such as leukotriene modifying agents, aspirin desensitization, biologic agents and ESS, appear to influence eicosanoid pathways, however more studies need to be done to further understand the role of oxylipins. Besides AA-derived eicosanoids, other oxylipins may also pay a role but have not been sufficiently studied. Identifying pathogenic N-ERD mechanism is likely to define more effective treatment targets.

Anti-inflammatory effects and improved metabolic derangements in ob/ob mice by a newly synthesized prenylated benzopyran with pan-PPAR activity

Background and purposeSelective peroxisome proliferator-activated receptors (PPARs) are widely used to treat metabolic complications; however, the limited effect of PPARα agonists on glucose metabolism and the adverse effects associated with selective PPARγ activators have stimulated the development of novel pan-PPAR agonists to treat metabolic disorders. Here, we synthesized a new prenylated benzopyran (BP-2) and evaluated its PPAR-activating properties, anti-inflammatory effects and impact on metabolic derangements. Experimental approachBP-2 was used in transactivation assays to evaluate its agonism to PPARα, PPARβ/δ and PPARγ. A parallel-plate flow chamber was employed to investigate its effect on TNFα-induced leukocyte-endothelium interactions. Flow cytometry and immunofluorescence were used to determine its effects on the expression of endothelial cell adhesion molecules (CAMs) and chemokines and p38-MAPK/NF-κB activation. PPARs/RXRα interactions were determined using a gene silencing approach. Analysis of its impact on metabolic abnormalities and inflammation was performed in ob/ob mice. Key resultsBP-2 displayed strong PPARα activity, with moderate and weak activity against PPARβ/δ and PPARγ, respectively. In vitro, BP-2 reduced TNFα-induced endothelial ICAM-1, VCAM-1 and fractalkine/CX3CL1 expression, suppressed mononuclear cell arrest via PPARβ/δ-RXRα interactions and decreased p38-MAPK/NF-κB activation. In vivo, BP-2 improved the circulating levels of glucose and triglycerides in ob/ob mice, suppressed T-lymphocyte/macrophage infiltration and proinflammatory markers in the liver and white adipose tissue, but increased the expression of the M2-like macrophage marker CD206. Conclusion and implicationsBP-2 emerges as a novel pan-PPAR lead candidate to normalize glycemia/triglyceridemia and minimize inflammation in metabolic disorders, likely preventing the development of further cardiovascular complications.

MyD88-TLR4-dependent choroid plexus activation precedes perilesional inflammation and secondary brain edema in a mouse model of intracerebral hemorrhage.

The functional neurological outcome of patients with intracerebral hemorrhage (ICH) strongly relates to the degree of secondary brain injury (ICH-SBI) evolving within days after the initial bleeding. Different mechanisms including the incitement of inflammatory pathways, dysfunction of the blood-brain barrier (BBB), activation of resident microglia, and an influx of blood-borne immune cells, have been hypothesized to contribute to ICH-SBI. Yet, the spatiotemporal interplay of specific inflammatory processes within different brain compartments has not been sufficiently characterized, limiting potential therapeutic interventions to prevent and treat ICH-SBI. We used a whole-blood injection model in mice, to systematically characterized the spatial and temporal dynamics of inflammatory processes after ICH using 7-Tesla magnetic resonance imaging (MRI), spatial RNA sequencing (spRNAseq), functional BBB assessment, and immunofluorescence average-intensity-mapping. We identified a pronounced early response of the choroid plexus (CP) peaking at 12-24h that was characterized by inflammatory cytokine expression, epithelial and endothelial expression of leukocyte adhesion molecules, and the accumulation of leukocytes. In contrast, we observed a delayed secondary reaction pattern at the injection site (striatum) peaking at 96h, defined by gene expression corresponding to perilesional leukocyte infiltration and correlating to the delayed signal alteration seen on MRI. Pathway analysis revealed a dependence of the early inflammatory reaction in the CP on toll-like receptor 4 (TLR4) signaling via myeloid differentiation factor 88 (MyD88). TLR4 and MyD88 knockout mice corroborated this observation, lacking the early upregulation of adhesion molecules and leukocyte infiltration within the CP 24h after whole-blood injection. We report a biphasic brain reaction pattern after ICH with a MyD88-TLR4-dependent early inflammatory response of the CP, preceding inflammation, edema and leukocyte infiltration at the lesion site. Pharmacological targeting of the early CP activation might harbor the potential to modulate the development of ICH-SBI.