Induction Of Adhesion Molecules Research Articles

Serum IgA augments adhesiveness of cultured lung microvascular endothelial cells and suppresses angiogenesis

Immunoglobulin A (IgA) is important in local immunity and is also abundant in the blood. This study aimed to evaluate the effects of serum IgA on cultured lung microvascular endothelial cells (HMVEC-Ls), which are involved in the pathogenesis of inflammatory lung diseases. Serum IgA induced adhesion molecules and inflammatory cytokine production from HMVEC-Ls, and enhanced adhesion of peripheral blood mononuclear cells to HMVEC-Ls. In contrast, migration, proliferation, and tube formation of HMVEC-Ls were significantly suppressed by serum IgA. Experiments with siRNAs and western blotting revealed that two known IgA receptors, β1,4-galactosyltransferase 1 (b4GALT1) and asialoglycoprotein receptor 1 (ASGR1), and mitogen-activated protein kinase and nuclear factor-kappa B pathways were partly involved in serum IgA-induced cytokine production by HMVEC-Ls. Collectively, serum IgA enhanced cytokine production and adhesiveness of HMVEC-L, with b4GALT1 and ASGR1 partially being involved, and suppressed angiogenesis. Thus, serum IgA may be targeted to treat inflammatory lung diseases.

TNFα increases the degradation of pyruvate dehydrogenase kinase 4 by the Lon protease to support proinflammatory genes

The endothelium is a major target of the proinflammatory cytokine, tumor necrosis factor alpha (TNFα). Exposure of endothelial cells (EC) to proinflammatory stimuli leads to an increase in mitochondrial metabolism; however, the function and regulation of elevated mitochondrial metabolism in EC in response to proinflammatory cytokines remain unclear. Studies using high-resolution metabolomics and 13C-glucose and 13C-glutamine labeling flux techniques showed that pyruvate dehydrogenase activity (PDH) and oxidative tricarboxylic acid cycle (TCA) flux are elevated in human umbilical vein ECs in response to overnight (16 h) treatment with TNFα (10 ng/mL). Mechanistic studies indicated that TNFα mediated these metabolic changes via mitochondrial-specific protein degradation of pyruvate dehydrogenase kinase 4 (PDK4, inhibitor of PDH) by the Lon protease via an NF-κB-dependent mechanism. Using RNA sequencing following siRNA-mediated knockdown of the catalytically active subunit of PDH, PDHE1α (PDHA1 gene), we show that PDH flux controls the transcription of approximately one-third of the genes that are up-regulated by TNFα stimulation. Notably, TNFα-induced PDH flux regulates a unique signature of proinflammatory mediators (cytokines and chemokines) but not inducible adhesion molecules. Metabolomics and ChIP sequencing for acetylated modification on lysine 27 of histone 3 (H3K27ac) showed that TNFα-induced PDH flux promotes histone acetylation of specific gene loci via citrate accumulation and ATP-citrate lyase-mediated generation of acetyl CoA. Together, these results uncover a mechanism by which TNFα signaling increases oxidative TCA flux of glucose to support TNFα-induced gene transcription through extramitochondrial acetyl CoA generation and histone acetylation.

Neflamapimod inhibits endothelial cell activation, adhesion molecule expression, leukocyte attachment and vascular inflammation by inhibiting p38 MAPKα and NF-κB signaling

Neflamapimod, a selective inhibitor of the alpha isoform of p38 mitogen-activated protein kinase (MAPKα), was investigated for its potential to inhibit lipopolysaccharide (LPS)-induced activation of endothelial cells (ECs), adhesion molecule induction, and subsequent leukocyte attachment to EC monolayers. These events are known to contribute to vascular inflammation and cardiovascular dysfunction. Our results demonstrate that LPS treatment of cultured ECs and rats leads to significant upregulation of adhesion molecules, both in vitro and in vivo, which can be effectively inhibited by neflamapimod treatment. Western blotting data further reveals that neflamapimod inhibits LPS-induced phosphorylation of p38 MAPKα and the activation of NF-κB signaling in ECs. Additionally, leukocyte adhesion assays demonstrate a substantial reduction in leukocyte attachment to cultured ECs and the aorta lumen of rats treated with neflamapimod. Consistent with vascular inflammation, LPS-treated rat arteries exhibit significantly diminished vasodilation response to acetylcholine, however, arteries from rats treated with neflamapimod maintain their vasodilation capacity, demonstrating its ability to limit LPS-induced vascular inflammation. Overall, our data demonstrate that neflamapimod effectively inhibits endothelium activation, adhesion molecule expression, and leukocyte attachment, thereby reducing vascular inflammation.

PtCu Nanosonosensitizers with Inflammatory Microenvironment Regulation for Enhanced Sonodynamic Bacterial Elimination and Tissue Repair

AbstractSonodynamic therapy (SDT) is considered a reliable replacement therapy to overcome the resistance to antibiotics and the limited tissue penetration of traditional photo‐induced therapy. Herein, ultrasmall platinum‐copper alloy nanoparticles (PtCu NPs) modified with poly (maleic anhydridealt‐1‐octadecene)‐polyethylene glycol (C18PMH‐PEG) with high sonodynamic activity, strong catalytic ability, and good glutathione (GSH) depletion performance are synthesized for highly efficient bacterial elimination. PtCu NPs obtained through a thermal decomposition approach can generate high toxic singlet oxygen (1O2) under ultrasound (US) irradiation, showing good sonodynamic performance. Meanwhile, the partial oxygenation formed on the surface of PtCu NPs endows them with good Fenton‐like catalytic performance and superior GSH‐depleting ability, thus enhancing reactive oxygen species (ROS) generation. In vitro experiments confirm that the synthesized PtCu‐ NPs can not only efficiently kill both gram‐positive and gram‐negative bacteria but also eliminate staphylococcus aureus (S. aureus) infection through ROS generation and then accelerate wound healing in the S. aureus‐infected wound model. Meanwhile, the copper ions released from PtCu NPs can promote cell migration and angiogenesis through the up‐regulation of hypoxia inducible factor (HIF‐1α) and platelet endothelial cell adhesion molecule (CD31). Finally, the S. aureus‐induced deep‐seated osteomyelitis infection and bone destruction were successfully inhibited by the PtCu‐mediated combination therapy. Our work highlights a novel SDT strategy for enhanced sonodynamic bacteria elimination and tissue repair.

Relation between macrophage inflammatory protein-1 and intercellular adhesion molecule-1 and computed tomography findings in critically-ill saudi covid-19 patients

BackgroundSeveral, clinical and biochemical factors were suggested as risk factors for more severe forms of Covid-19. Macrophage inflammatory protein-1 alpha (MIP-1α, CCL3) is a chemokine mainly involved in cell adhesion and migration. Intracellular adhesion molecule 1 (ICAM-1) is an inducible cell adhesion molecule involved in multiple immune processes. The present study aimed to assess the relationship between baseline serum MIP-1α and ICAM-1 level in critically-ill Covid-19 patients and the severity of computed tomography (CT) findings. MethodsThe study included 100 consecutive critically-ill patients with Covid-19 infection. Diagnosis of infection was established on the basis of RT-PCR tests. Serum MIP-1α and ICAM-1 levels were assessed using commercially available ELISA kits. All patients were subjected to a high-resolution computed tomography assessment. ResultsAccording to the computed tomography severity score, patients were classified into those with moderate/severe (n=49) and mild (n = 51) pulmonary involvement. Severe involvement was associated with significantly higher MIP-1α and ICAM-1 level. Correlation analysis identified significant positive correlations between MIP-1α and age, D-dimer, IL6, in contrast, there was an inverse correlation with INF-alpha. Additionally, ICAM-1 showed significant positive correlations with age, D‐Dimer,- TNF—α, IL6,while an inverse correlation with INF-alpha was observed. ConclusionsMIP-1α and ICAM-1 level are related to CT radiological severity in Covid-19 patients. Moreover, these markers are well-correlated with other inflammatory markers suggesting that they can be used as reliable prognostic markers in Covid-19 patients.

Solvent extraction optimisation and validation of the HPLC-DAD method for quantification of 5-hydroxyindolin-2-one inProtaetia brevitarsis seulensis larvae extracts

Recent studies on the composition of edible insects have placed more emphasis on the quantity and quality of macro- and micronutrients and less emphasis on their bioactive components. This study aimed to assess the effect of 0-100% ethanol solvent ratio considering 5-hydroxyindolin-2-one (5-HI) content on the extraction efficiency inProtaetia brevitarsis seulensis larvae (PBSL) extract and to investigate the effect of PBSL on the induction of cell adhesion molecules (CAMs) in tumour necrosis factor (TNF)-α-activated human umbilical vein endothelial cells (HUVECs). A reversed-phase high-performance liquid chromatography method coupled to a diode array detector (HPLC-DAD) was validated for the quantification of 5-HI. The HPLC-DAD method was validated for its specificity, linearity, precision, accuracy, limit of detection, and limits of quantitation. The calibration curve of 5-HI showed significant linearity (R2>1). The limits of detection and quantitation were 0.016 μg/ml and 0.048 μg/ml, respectively. The relative standard deviation of the precision and intraday tests was less than 0.5%. In the recovery test, the accuracy ranged from 94.48-105.5% and the relative standard deviation value was less than 0.13%. The method validation parameters indicate the applicability of the HPLC method for quality control of food or pharmaceutical formulations containing PBSL. Comparative analysis of the 5-HI content by extraction solvent revealed that it was the highest at 357.7 μg/ml in 70% ethanol. Additionally, the analysis result of 5-HI content according to the growth conditions was the highest at 439 μg/ml at 31 °C for 30 days. Furthermore, in the condition where PBSL was at 31 °C for 30 days inhibition of the TNF-α-induced upregulation of protein expression of vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), and endothelial-leukocyte adhesion molecule-1 (E-selectin) was observed. Therefore, PBSL may interfere with early atherosclerotic events involving endothelial CAM induction.

SARS-CoV-2 Infection of Airway Epithelium Triggers Pulmonary Endothelial Cell Activation and Senescence Associated with Type I IFN Production.

Airway epithelial cells represent the main target of SARS-CoV-2 replication but several pieces of evidence suggest that endothelial cells (ECs), lining pulmonary blood vessels, are key players in lung injury in COVID-19 patients. Although in vivo evidence of SARS-CoV-2 affecting the vascular endothelium exists, in vitro data are limited. In the present study, we set up an organotypic model to dissect the crosstalk between airway epithelium and pulmonary endothelial cells during SARS-CoV-2 infection. We showed that SARS-CoV-2 infected airway epithelium triggers the induction of endothelial adhesion molecules in ECs, suggesting a bystander effect of dangerous soluble signals from the infected epithelium. The endothelial activation was correlated with inflammatory cytokines (IL-1β, IL-6, IL-8) and with the viral replication in the airway epithelium. Interestingly, SARS-CoV-2 infection determined a modulation of endothelial p21, which could be partially reversed by inhibiting IFN-β production from ECs when co-cultured with HAE. Altogether, we demonstrated that SARS-CoV-2 infected epithelium triggers activation/senescence processes in ECs involving type I IFN-β production, suggesting possible antiviral/damage mechanisms occurring in the endothelium.

Mediators of Obesity Do Not Influence SARS-CoV-2 Infection or Activation of Primary Human Lung Microvascular Endothelial Cells In Vitro.

Clinical observations have shown that obesity is associated with the severe outcome of SARS-CoV-2 infection hallmarked by microvascular dysfunction in the lungs and other organs. Excess visceral fat and high systemic levels of adipose tissue (AT) derived mediators such as leptin and other adipokines have also been linked to endothelial dysfunction. Consequently, we hypothesized that AT-derived mediators may exacerbate microvascular dysfunction during of SARS-CoV-2 infection and tested this in a primary human lung microvascular endothelial (HLMVEC) cell model. Our results indicate that HLMVEC are not susceptible to SARS-CoV-2 infection since no expression of viral proteins and no newly produced virus was detected. In addition, exposure to the virus did not induce endothelial activation as evidenced by a lack of adhesion molecule, E-selectin, VCAM-1, ICAM-1, and inflammatory cytokine IL-6 induction. Incubation of endothelial cells with the pro-inflammatory AT-derived mediator, leptin, prior to virus inoculation, did not alter the expression of endothelial SARS-CoV-2 entry receptors and did not alter their susceptibility to infection. Furthermore, it did not induce inflammatory activation of endothelial cells. To verify if the lack of activated phenotype in the presence of adipokines was not leptin-specific, we exposed endothelial cells to plasma obtained from critically ill obese COVID-19 patients. Plasma exposure did not result in E-selectin, VCAM-1, ICAM-1, or IL-6 induction. Together our results strongly suggest that aberrant inflammatory endothelial responses are not mounted by direct SARS-CoV-2 infection of endothelial cells, even in the presence of leptin and other mediators of obesity. Instead, endothelial activation associated with COVID-19 is likely a result of inflammatory responses initiated by other cells. Further studies are required to investigate the mechanisms regulating endothelial behavior in COVID-19 and the mechanisms driving severe disease in obese individuals.

SARS-CoV-2 productively infects human brain microvascular endothelial cells

BackgroundThe emergence of the novel, pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global health emergency. SARS-CoV-2 is highly contagious and has a high mortality rate in severe patients. However, there is very limited information on the effect of SARS-CoV-2 infection on the integrity of the blood–brain barrier (BBB).MethodsRNA-sequencing profiling was performed to analyze the transcriptomic changes in human brain microvascular endothelial cells (hBMECs) after SARS-CoV-2 infection. Bioinformatic tools were used for differential analysis. Immunofluorescence, real-time quantitative PCR, and Western blotting analysis were used to explore biological phenotypes.ResultsA total of 927 differentially expressed genes were identified, 610 of which were significantly upregulated while the remaining 317 were downregulated. We verified the significant induction of cytokines, chemokines, and adhesion molecules in hBMECs by SARS-CoV-2, suggesting an activation of the vascular endothelium in brain. Moreover, we demonstrated that SARS-CoV-2 infection could increase the BBB permeability, by downregulating as well as remodeling the intercellular tight junction proteins.ConclusionsOur findings demonstrated that SARS-CoV-2 infection can cause BBB dysfunction, providing novel insights into the understanding of SARS-CoV-2 neuropathogenesis. Moreover, this finding shall constitute a new approach for future prevention and treatment of SARS-CoV-2-induced CNS infection.

Vascular E-selectin Expression Detected in Formalin-fixed, Paraffin-embedded Sections With an E-selectin Monoclonal Antibody Correlates With Ulcerative Colitis Activity.

It is widely accepted that E-selectin, an inducible endothelial cell adhesion molecule, plays a critical role in the initial step of neutrophil recruitment to sites of acute inflammation. However, immunohistological analysis of E-selectin has been hampered by lack of E-selectin-specific monoclonal antibodies that can stain formalin-fixed, paraffin-embedded (FFPE) tissue sections. Here, we employed E-selectin•IgM (a soluble form of E-selectin) as immunogen, and then, after negative selection with L-selectin•IgM and P-selectin•IgM and screening of FFPE sections of both COS-1 cells overexpressing E-selectin and acute appendicitis tissues, we successfully generated an E-selectin-specific monoclonal antibody capable of staining FFPE tissue sections. We used this antibody, designated U12-12, to perform quantitative immunohistological analysis of 390 colonic mucosal biopsy specimens representing ulcerative colitis. We found that the higher the histological disease activity, the greater the number of vessels expressing E-selectin, an observation consistent with previous analyses of frozen tissue sections. Furthermore, in active ulcerative colitis, E-selectin-expressing vessels contained neutrophils attached to endothelial cells, presumably in the process of extravasation, which eventually could cause epithelial damage. These results overall indicate that U12-12 is effective for E-selectin immunohistochemistry in archived FFPE samples representing various human diseases.

Deletion of BACH1 Attenuates Atherosclerosis by Reducing Endothelial Inflammation.

The transcription factor BACH1 (BTB and CNC homology 1) suppressed endothelial cells (ECs) proliferation and migration and impaired angiogenesis in the ischemic hindlimbs of adult mice. However, the role and underlying mechanisms of BACH1 in atherosclerosis remain unclear. Mouse models of atherosclerosis in endothelial cell (EC)-specific-Bach1 knockout mice were used to study the role of BACH1 in the regulation of atherogenesis and the underlying mechanisms. Genetic analyses revealed that coronary artery disease-associated risk variant rs2832227 was associated with BACH1 gene expression in carotid plaques from patients. BACH1 was upregulated in ECs of human and mouse atherosclerotic plaques. Endothelial Bach1 deficiency decreased turbulent blood flow- or western diet-induced atherosclerotic lesions, macrophage content in plaques, expression of endothelial adhesion molecules (ICAM1 [intercellular cell adhesion molecule-1] and VCAM1 [vascular cell adhesion molecule-1]), and reduced plasma TNF-α (tumor necrosis factor-α) and IL-1β levels in atherosclerotic mice. BACH1 deletion or knockdown inhibited monocyte-endothelial adhesion and reduced oscillatory shear stress or TNF-α-mediated induction of endothelial adhesion molecules and/or proinflammatory cytokines in mouse ECs, human umbilical vein ECs, and human aortic ECs. Mechanistic studies showed that upon oscillatory shear stress or TNF-α stimulation, BACH1 and YAP (yes-associated protein) were induced and translocated into the nucleus in ECs. BACH1 upregulated YAP expression by binding to the YAP promoter. BACH1 formed a complex with YAP inducing the transcription of adhesion molecules. YAP overexpression in ECs counteracted the antiatherosclerotic effect mediated by Bach1-deletion in mice. Rosuvastatin inhibited BACH1 expression by upregulating microRNA let-7a in ECs, and decreased Bach1 expression in the vascular endothelium of hyperlipidemic mice. BACH1 was colocalized with YAP, and the expression of BACH1 was positively correlated with YAP and proinflammatory genes, as well as adhesion molecules in human atherosclerotic plaques. These data identify BACH1 as a mechanosensor of hemodynamic stress and reveal that the BACH1-YAP transcriptional network is essential to vascular inflammation and atherogenesis. BACH1 shows potential as a novel therapeutic target in atherosclerosis.

Polystyrene microplastic particles induce endothelial activation.

Due to its increasing production, durability and multiple applications, plastic is a material we encounter every day. Small plastic particles from the μm to the mm range are classified as microplastics and produced for cosmetic and medical products, but are also a result of natural erosion and decomposition of macroplastics. Although being omnipresent in our environment and already detected in various organisms, less is known about the effects of microplastics on humans in general, or on vascular biology in particular. Here we investigated the effects of carboxylated polystyrene microplastic particles (PS, 1 μm) on murine endothelial and immune cells, which are both crucially involved in vascular inflammation, using in vitro and in vivo approaches. In vitro, PS induced adhesion molecule expression in endothelial cells with subsequent adhesion of leukocytes both under static and flow conditions. In monocytic cells, PS enhanced pro-inflammatory cytokine expression and release. Accordingly, administering mice with PS led to enhanced aortic expression of cytokines and adhesion molecules. Furthermore, we identified neutrophils as the PS-clearing blood leukocyte population. The findings from this study for the first time indicate polystyrene microplastic as a new environmental risk factor for endothelial inflammation.

HIV-infected patients display increased proatherogenic anti-apolipoprotein A1 autoantibodies, inflammatory and metabolomic markers

Abstract Background HIV-infected patients display an increased risk of cardiovascular events. HIV and antiretroviral therapy (ART) have both been suggested to increase this risk but their specific role remains unclear. Autoantibodies against apolipoprotein A1 (anti-apoA1 IgG) are also associated with cardiovascular risk. The aim of this study was to analyse anti-apoA1 IgG levels and inflammatory markers as well as the metabolomic profile in a cohort of HIV-free, ART-experienced and naïve HIV-infected patients. Methods 144 participants from a South African cohort were categorised into HIV-free (n=50), HIV-infected/ART-experienced (n=50) and HIV-infected/ART-naïve (n=44) groups. The levels of anti-apoA1 IgG were assessed by homemade ELISA assays. We performed targeted metabolomic analyses using standard operating procedures and measured inflammatory biomarkers using the Meso Scale Discovery® platform. Additionally, we conducted in vitro experiments on human aortic endothelial cells treated with anti-apoA1 IgG and assessed levels of adhesion molecules. Results Inflammatory markers (IFNg, IL-6, IL-10, TNFa, CRP all p<0.05), circulating adhesion molecules (ICAM-1 and VCAM-1, p<0.05), anti-apoA1 IgG levels were increased in HIV-infected patients compared to HIV-free participants. While ART treatment significantly reduced IFNg, IL-10, TNFa, VCAM-1, anti-apoA1 IgG levels, no significant differences were observed in other biomarkers between ART-experienced and naïve participants. Treatment of human aortic endothelial cells with anti-apoA1 IgG (40μg/ml) induced a significant increase in these adhesion molecules compared to cells treated with control IgG (40μg/ml). Metabolomic analyses identified 257 endogenous circulating metabolites in plasma. Among these metabolites, we found that in HIV-free and infected patients 14 and 17 metabolites were significantly correlated with anti-apoA1 IgG levels, respectively. Among these 17 metabolites, 2 were positively correlated with the tryptophan pathway; kynurenine (r=0.292, p=0.0069) and 5-hydroxyindolacetate (r=0.316, p=0.0019). Interestingly, kynurenine was not significantly correlated with anti-apoA1 IgG levels in HIV-free patients. Conclusion HIV-infected patients displayed a more proatherogenic profile compared to HIV-free subjects. Anti-apoA1 IgG induced adhesion molecules expression. Metabolomics identified metabolites that were significantly associated with anti-apoA1 IgG levels and inflammatory biomarkers known to underlie atherosclerosis burden. Funding Acknowledgement Type of funding sources: None.

Poldip2 controls leukocyte infiltration into the ischemic brain by regulating focal adhesion kinase-mediated VCAM-1 induction

Stroke is a multiphasic process involving a direct ischemic brain injury which is then exacerbated by the influx of immune cells into the brain tissue. Activation of brain endothelial cells leads to the expression of adhesion molecules such vascular cell adhesion molecule 1 (VCAM-1) on endothelial cells, further increasing leukocyte recruitment. Polymerase δ-interacting protein 2 (Poldip2) promotes brain vascular inflammation and leukocyte recruitment via unknown mechanisms. This study aimed to define the role of Poldip2 in mediating vascular inflammation and leukocyte recruitment following cerebral ischemia. Cerebral ischemia was induced in Poldip2+/+ and Poldip2+/− mice and brains were isolated and processed for flow cytometry or RT-PCR. Cultured rat brain microvascular endothelial cells were used to investigate the effect of Poldip2 depletion on focal adhesion kinase (FAK)-mediated VCAM-1 induction. Poldip2 depletion in vivo attenuated the infiltration of myeloid cells, inflammatory monocytes/macrophages and decreased the induction of adhesion molecules. Focusing on VCAM-1, we demonstrated mechanistically that FAK activation was a critical intermediary in Poldip2-mediated VCAM-1 induction. In conclusion, Poldip2 is an important mediator of endothelial dysfunction and leukocyte recruitment. Thus, Poldip2 could be a therapeutic target to improve morbidity following ischemic stroke.

Effects of Nicorandil on Inflammation, Apoptosis and Atherosclerotic Plaque Progression.

Nicorandil, a balanced vasodilator, is used in the second-line therapy of angina pectoris. In this study, we aimed to illuminate the effects of nicorandil on inflammation, apoptosis, and atherosclerotic plaque progression. Twenty-five LDL-R -/- mice were fed a high-fat diet for 14 weeks. After 6 weeks mice were randomly allocated to treatment with nicorandil (10 mg/kg/day) or tap water. Nicorandil treatment led to a more stable plaque phenotype, displaying an increased thickness of the fibrous cap (p = 0.014), a significant reduction in cholesterol clefts (p = 0.045), and enhanced smooth muscle cell content (p = 0.009). In endothelial cells nicorandil did not reduce the induction of adhesion molecules or proinflammatory cytokines. In H2O2 challenged endothelial cells, pretreatment with nicorandil significantly reduced the percentage of late apoptotic/necrotic cells (p = 0.016) and the ratio of apoptotic to living cells (p = 0.036). Atherosclerotic lesions of animals treated with nicorandil exhibited a significantly decreased content of cleaved caspase-3 (p = 0.034), lower numbers of apoptotic nuclei (p = 0.040), and reduced 8-oxogunanine staining (p = 0.039), demonstrating a stabilizing effect of nicorandil in established atherosclerotic lesions. We suggest that nicorandil has a positive effect on atherosclerotic plaque stabilization by reducing apoptosis.

IPSC-derived endothelial cells from high-risk cad patients demonstrate increased inducible adhesion molecule upregulation by inflammatory stimulation and gap closure delay compared to healthy controls

Background and Aims: Atherosclerosis remains a leading cause of death worldwide. Thus, it is imperative to not only illuminate the general pathomechanism but also investigate the underlying mechanisms in genetically predisposed patients. Here, induced pluripotent stem cells (iPSC) are an ideal tool to experimentally separate the impact of a donor´s genetic background from their lifestyle on cardiovascular disease risk in pathomechanistic studies.

ESM-1 Overexpression is Involved in Increased Tumorigenesis of Radiotherapy-Resistant Breast Cancer Cells.

The key barrier to the effectiveness of radiotherapy remains the radioresistance of breast cancer cells, resulting in increased tumor recurrence and metastasis. Thus, in this study, we aimed to clarify the difference between radiotherapy-resistant (RT-R) breast cancer (BC) and BC, and accordingly, analyzed gene expression levels between radiotherapy-resistant (RT-R) MDA-MB-231 cells and MDA-MB-231 cells. Gene expression array showed that ESM-1 was the most upregulated in RT-R-MDA-MB-231 cells compared to MDA-MB-231 cells. Then, we aimed to investigate the role of ESM-1 in the increased tumorigenesis of RT-R-BC cells. RT-R-MDA-MB-231, which showed an increased expression level of ESM1, exhibited significantly enhanced proliferation, colony forming ability, migration, and invasion compared to MDA-MB-231 cells, and ESM-1 knockdown effectively reversed these effects. In addition, compared to MDA-MB-231 cells, RT-R-MDA-MB-231 cells displayed improved adhesion to endothelial cells (ECs) due to the induction of adhesion molecules and increased MMP-9 activity and VEGF-A production, which were decreased by ESM-1 knockdown. Moreover, the expression of HIF-1α and activation of NF-κB and STAT-3 were increased in RT-R-MDA-MB-231 cells compared to MDA-MB-231 cells, and these effects were abolished by the knockdown of ESM-1. Finally, we confirmed the role of ESM-1 in tumorigenesis in an in vivo mouse model. Tumor volume, lung metastasis, and tumorigenic molecules (VEGF-A, HIF-1α, MMP-9, ICAM-1, VCAM-1, and phospho-NF-κB and phospho-STAT-3) were significantly induced in mice injected with ESM-1-overexpressing 4T1 cells and greatly enhanced in those injected with ESM-1-overexpressing RT-R-4T1 cells. Taken together, these results suggest for the first time that ESM-1 plays a critical role in tumorigenesis of breast cancer cells, especially RT-R-breast cancer cells, through the induction of cell proliferation and invasion.

Chronic Peripheral Inflammation Causes a Region-Specific Myeloid Response in the Central Nervous System

Systemic immune dysregulation contributes to the development of neuropsychiatric and neurodegenerative diseases. The precise effect of chronic peripheral immune stimulation on myeloid cells across anatomical brain regions is unclear. Here, we demonstrate brain-region-specific differences in myeloid responses induced by chronic peripheral inflammation. This shift in the myeloid compartment is associated with the appearance of an inflammatory myeloid subpopulation in the cortex, striatum, and thalamus accompanied by regional transcriptomic fingerprints that include induction of chemokines, complement factors, and endothelial adhesion molecules. In contrast, myeloid immune responses within the hippocampus and cerebellum are subtle or absent. Treatment with the anti-tumor necrosis factor α (anti-TNF-α) antibody infliximab ablates the region-specific inflammatory response. A region-specific myeloid cell response to chronic peripheral inflammation is observed in postmortem brains from individuals with rheumatoid arthritis. Our data suggest that chronic peripheral inflammation has heterogeneous effects on the brain, as evidenced by the spectrum of myeloid cell responses observed across brain regions.

Attenuation of neutrophil-mediated liver injury in mice by drug-free E-selectin binding polymer

Inflammation with neutrophils infiltration is a prominent feature of alcohol-related liver disease (ARLD) and contributes to the severity of liver injury. Although an array of potential treatments has been studied, the standard treatment regimen is controversial and can induce severe side effects and infection-related complications. E-selectin, a cytokine inducible cell adhesion molecule, mediates the initial interaction of leucocytes with endothelial cells, and facilitates their further adhesion and extravasation into inflamed tissues. Given the important role of E-selectin in leukocytes trafficking, we hypothesized that a synthetic polymer presenting multiple copies of E-selectin binding peptide in a polyvalent manner (P-Esbp) may block the “roads” that facilitate neutrophil infiltration, inhibit the recruitment of neutrophils to the inflamed sites and reduce the extent of liver injury. We now demonstrate in vitro that P-Esbp reduced the recruitment of neutrophils (collected from blood of donors) on activated human umbilical vein endothelial cells (HUVEC) under flow conditions. Pre-treatment of mice with P-Esbp prior to alcohol binge attenuated alcohol-induced serum transaminase (ALT, AST) elevation, reduced pro-inflammatory cytokines (TNFα and IL-1ẞ) and chemokines (MIP-2/CXCL2 and MCP-1/CCL2) in National Institute on Alcohol Abuse and Alcoholism (NIAAA) model. Also, the up-regulation of neutrophil marker Ly6G and the number of MPO positive cells in the injured tissue was significantly reduced by the treatment, indicating diminished neutrophil infiltration. Moreover, as a result of P-Esbp treatment, E-selectin expression in the liver (mRNA and protein level) was downregulated, suggesting a potential to decrease ongoing local inflammatory response. Overall, our findings highlight the anti-inflammatory properties of the “drug-free” P-Esbp and its therapeutic potential to attenuate an excessive inflammation where infiltrating neutrophils can damage tissues and organs.

Innate Immune Dysfunction in Rosacea Promotes Photosensitivity and Vascular Adhesion Molecule Expression

Rosacea is a chronic skin disease characterized by photosensitivity, abnormal dermal vascular behavior, inflammation, and enhanced expression of the antimicrobial peptide LL-37. We observed that dermal endothelial cells in rosacea had an increased expression of VCAM1 and hypothesized that LL-37 could be responsible for this response. The digestion of double-stranded RNA from keratinocytes exposed to UVB blocked the capacity of these cells to induce adhesion molecules on dermal microvascular endothelial cells. However, a synthetic noncoding snoU1RNA was only capable of increasing adhesion molecules on endothelial cells in the presence of LL-37, suggesting that the capacity of UVB exposure to promote both double-stranded RNA and LL-37 was responsible for the endothelial response to keratinocytes. Sequencing of RNA from the endothelial cells uncovered the activation of Gene Ontology (GO) pathways relevant to the human disease, such as type I and II interferon signaling, cell-cell adhesion, leukocyte chemotaxis, and angiogenesis. Functional relevance was demonstrated as double-stranded RNA and LL-37 promoted adhesion and transmigration of monocytes across the endothelial cell monolayers. Gene knockdown of TLR3, RIGI, or IRF1 decreased monocyte adhesion in endothelial cells, confirming the role of the double-stranded RNA recognition pathways. These observations show how the expression of LL-37 can lead to enhanced sensitivity to UVB radiation in rosacea.