Endothelial Inflammatory Activation Research Articles

Sepsis induces heterogeneous transcription of coagulation- and inflammation-associated genes in renal microvasculature

BackgroundAcute kidney injury (AKI) in sepsis patients increases patient mortality. Endothelial cells are important players in the pathophysiology of sepsis-associated AKI (SA-AKI), yet knowledge regarding their spatiotemporal involvement in coagulation disbalance and leukocyte recruitment is lacking. This study investigated the identity and kinetics of responses of different microvascular compartments in kidney cortex in response to SA-AKI. MethodsLaser microdissected arterioles, glomeruli, peritubular capillaries, and postcapillary venules from kidneys of mice subjected to cecal ligation and puncture (CLP) were analyzed using RNA sequencing. Differential expression and pathway enrichment analyses identified genes involved in coagulation and inflammation. A selection of these genes was evaluated by RT-qPCR in microvascular compartments of renal biopsies from patients with SA-AKI. The role of two identified genes in lipopolysaccharide-induced endothelial coagulation and inflammatory activation were determined in vitro in HUVEC using siRNA-based gene silencing. ResultsCLP-sepsis in mice induced altered expression of approximately 400 genes in the renal microvasculature, with microvascular compartments exhibiting unique spatiotemporal responses. In mice, changes in gene expression related to coagulation and inflammation were most extensive in glomeruli at early and intermediate time points, with high induction of Plat, Serpine1, Thbd, Icam1, Stat3, and Ifitm3. In human SA-AKI, PROCR and STAT3 were induced in postcapillary venules, while SERPINE1 expression was diminished. IFITM3 was increased in arterioles and glomeruli. In vitro studies revealed that STAT3 and IFITM3 partly control endothelial coagulation and inflammatory activation. ConclusionRenal microvascular compartments in mice and humans exhibited heterogeneous changes in coagulation- and inflammation-related gene expression in response to SA-AKI. Additional research should aim at understanding the functional consequences of the here described heterogeneous microvascular responses to establish the usefulness of identified genes as therapeutic targets in SA-AKI.

Integrated analysis of the lncRNA-associated competing endogenous RNA network in salt sensitivity of blood pressure

Accumulating evidence showed that competing endogenous RNA (ceRNA) mechanism plays a pivotal role in salt sensitivity of blood pressure (SSBP). We constructed a ceRNA network based on SSBP-related differently expressed lncRNAs (2), mRNAs (73) and miRNAs (18). Bioinformatic analyses were utilized to analyze network and found network genes participate in biological pathways related to SSBP pathogenesis such as regulation of nitric oxide biosynthetic process (GO:0045,428) and cellular response to cytokine stimulus (GO:0071,345). Fourteen candidate ceRNA pathways were selected from network to perform qRT-PCR validation and found nine RNAs (KCNQ1OT1, SLC8A1-AS1, IL1B, BCL2L11, KCNJ15, CX3CR1, KLF2, hsa-miR-362–5p and hsa-miR-423–5p) differently expressed between salt-sensitive (SS) and salt-resistant (SR) groups (P < 0.05). Four ceRNA pathways were further validated by luciferase reporter assay and found KCNQ1OT1→hsa-miR-362–5p/hsa-miR-423–5p→IL1B pathways may influence the pathogenic mechanism of SS. Our findings suggested the ceRNA pathway and network may affect SS occurrence mainly through endothelial dysfunction and inflammatory activation.

Amphipathic Helical Peptide L37pA Protects against Lung Vascular Endothelial Dysfunction Caused by Truncated Oxidized Phospholipids via Antagonism with CD36 Receptor.

The generation of bioactive truncated oxidized phospholipids (Tr-OxPLs) from oxidation of cell-membrane or circulating lipoproteins is a common feature of various pathological states. Scavenger receptor CD36 is involved in lipid transport and acts as a receptor for Tr-OxPLs. Interestingly, Tr-OxPLs and CD36 are involved in endothelial dysfunction-derived acute lung injury, but the precise mechanistic connections remain unexplored. In the present study, we investigated the role of CD36 in mediating pulmonary endothelial cell (EC) dysfunction caused by Tr-OxPLs. Our results demonstrated that the Tr-OxPLs KOdia-PC, Paz-PC, PGPC, PON-PC, POV-PC, and lysophosphocholine caused an acute EC barrier disruption as revealed by measurements of transendothelial electrical resistance and VE-cadherin immunostaining. More importantly, a synthetic amphipathic helical peptide, L37pA, targeting human CD36 strongly attenuated Tr-OxPL-induced EC permeability. L37pA also suppressed Tr-OxPL-induced endothelial inflammatory activation monitored by mRNA expression of inflammatory cytokines/chemokines and adhesion molecules. In addition, L37pA blocked Tr-OxPL-induced NF-κB activation and tyrosine phosphorylation of Src kinase and VE-cadherin. The Src inhibitor SU6656 attenuated KOdia-PC-induced EC permeability and inflammation, but inhibition of the Toll-like receptors (TLRs) TLR1, TLR2, TLR4, and TLR6 had no such protective effects. CD36-knockout mice were more resistant to Tr-OxPL-induced lung injury. Treatment with L37pA was equally effective in ameliorating Tr-OxPL-induced vascular leak and lung inflammation as determined by an Evans blue extravasation assay and total cell and protein content in BAL fluid. Altogether, these results demonstrate an essential role of CD36 in mediating Tr-OxPL-induced EC dysfunction and suggest a strong therapeutic potential of CD36 inhibitory peptides in mitigating lung injury and inflammation.

Changes in Adenosine Deaminase Activity and Endothelial Dysfunction after Mild Coronavirus Disease-2019.

Endothelial cells are a preferential target for SARS-CoV-2 infection. Previously, we have reported that vascular adenosine deaminase 1 (ADA1) may serve as a biomarker of endothelial activation and vascular inflammation, while ADA2 plays a critical role in monocyte and macrophage function. In this study, we investigated the activities of circulating ADA isoenzymes in patients 8 weeks after mild COVID-19 and related them to the parameters of inflammation and microvascular/endothelial function. Post-COVID patients revealed microvascular dysfunction associated with the changes in circulating parameters of endothelial dysfunction and inflammatory activation. Interestingly, serum total ADA and ADA2 activities were diminished in post-COVID patients, while ADA1 remained unchanged in comparison to healthy controls without a prior diagnosis of SARS-CoV-2 infection. While serum ADA1 activity tended to positively correspond with the parameters of endothelial activation and inflammation, sICAM-1 and TNFα, serum ADA2 activity correlated with IL-10. Simultaneously, post-COVID patients had lower circulating levels of ADA1-anchoring protein, CD26, that may serve as an alternative receptor for virus binding. This suggests that after the infection CD26 is rather maintained in cell-attached form, enabling ADA1 complexing. This study points to the possible role of ADA isoenzymes in cardiovascular complications after mild COVID-19.

MC3/SAINT-O-Somes, a novel liposomal delivery system for efficient and safe delivery of siRNA into endothelial cells

Increased understanding of chronic inflammatory diseases and the role of endothelial cell (EC) activation herein, have urged interest in sophisticated strategies to therapeutically intervene in activated EC to treat these diseases. Liposome-mediated delivery of therapeutic siRNA in inflammation-activated EC is such a strategy. In this study, we describe the design and characterisation of two liposomal siRNA delivery systems formulated with the cationic MC3 lipid or MC3/SAINT mixed lipids, referred to as MC3-O-Somes (MOS) and MC3/SAINT-O-Somes (MSS). The two formulations showed comparable physicochemical properties, except for better siRNA encapsulation efficiency in the MSS formulation. Antibody-mediated VCAM-1 targeting (AbVCAM-1) increased the association of the targeted MOS and MSS with activated EC, although the targeted MOS showed a significantly higher VCAM-1 specific association than the targeted MSS. AbVCAM-1 MSS containing RelA siRNA achieved significant downregulation of RelA expression, while AbVCAM-1 MOS containing RelA siRNA did not downregulate RelA expression in activated EC. Additionally, AbVCAM-1 MSS containing RelA siRNA showed low cytotoxicity in EC and at the same time prohibited endothelial inflammatory activation by reducing expression of cell adhesion molecules. The AbVCAM-1 MSS formulation is a novel siRNA delivery system based on a combination of the cationic lipids MC3 and SAINT, that shows good physicochemical characteristics, enhanced endothelial cell association, improved transfection activity, low toxicity and significant anti-inflammatory effect, thereby complying with the requirements for future in vivo investigations.

Correction to: EVA1A (Eva-1 Homolog A) Promotes Endothelial Apoptosis and Inflammatory Activation Under Disturbed Flow Via Regulation of Autophagy.

HomeArteriosclerosis, Thrombosis, and Vascular BiologyVol. 43, No. 6Correction to: EVA1A (Eva-1 Homolog A) Promotes Endothelial Apoptosis and Inflammatory Activation Under Disturbed Flow Via Regulation of Autophagy Free AccessCorrectionPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessCorrectionPDF/EPUBCorrection to: EVA1A (Eva-1 Homolog A) Promotes Endothelial Apoptosis and Inflammatory Activation Under Disturbed Flow Via Regulation of Autophagy Originally published24 May 2023https://doi.org/10.1161/ATV.0000000000000163Arteriosclerosis, Thrombosis, and Vascular Biology. 2023;43:e230This article corrects the followingEVA1A (Eva-1 Homolog A) Promotes Endothelial Apoptosis and Inflammatory Activation Under Disturbed Flow Via Regulation of AutophagyIn the article by Canham et al, “EVA1A (Eva-1 Homolog A) Promotes Endothelial Apoptosis and Inflammatory Activation Under Disturbed Flow Via Regulation of Autophagy,” which published in the April 2023 issue of the journal (Arterioscler Thromb Vasc Biol. 2023;43:547–561. doi: 10.1161/ATVBAHA.122.318110), a correction was needed.An additional affiliation was added for Paul C. Evans: William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom.This correction has been made to the current online version of the article, which is available at www.ahajournals.org/doi/10.1161/ATVBAHA.122.318110. Previous Back to top Next FiguresReferencesRelatedDetailsRelated articlesEVA1A (Eva-1 Homolog A) Promotes Endothelial Apoptosis and Inflammatory Activation Under Disturbed Flow Via Regulation of AutophagyLindsay Canham, et al. Arteriosclerosis, Thrombosis, and Vascular Biology. 2023;43:547-561 June 2023Vol 43, Issue 6 Advertisement Article InformationMetrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/ATV.0000000000000163 Originally publishedMay 24, 2023 PDF download Advertisement

Abstract 251: Regulation Of Endotheliopathy By Chromatin-associated Long Non-coding RNA

Lining the critical interface between circulating blood and vascular wall, endothelial cells (ECs) play vital functions in health and disease. The optimal gene expression in ECs is essential to maintain endothelial homeostasis, and its dysregulation can lead to EC dysfunction or endotheliopathy, a common mechanism underlying many metabolic and cardiovascular diseases. Through chromatin-RNA contact profiling, we have identified several chromatin-associated long non-coding RNA (lncRNAs) that play essential roles in the regulation of endothelial function, including endothelial nitric oxide production, angiogenesis, endothelial-mesenchymal transition, and inflammatory activation. These include nuclear genome-transcribed lncRNAs, e.g. lncRNA-enhancing endothelial nitric oxide synthase (LEENE) and LINC00607 that promotes expression of fibronectin and plasminogen activator inhibitor-1. Our recent study has also revealed that mitochondria transcribed RNAs (mtRNA) are pervasively attached to nuclear chromatin and such mtRNA-association with chromatin is increased by pro-inflammatory, diabetes-mimicking stimuli. Suppression of a mitochondrial lncRNA in ECs attenuates nascent RNA transcription from the nuclear genome, including that of critical genes promoting pro-inflammatory activation. Finally, we show increased nuclear localization of multiple mtRNAs in the ECs of human diabetic donors. Together, these data highlight an emerging role of chromatin-associated lncRNAs in regulating endothelial biology.

Intravenous iron supplementation in heart failure patients induces temporary endothelial dysfunction with release of endothelial microvesicles.

Intravenous iron supplementation is an established therapy for patients with heart failure (HF) and concomitant iron deficiency reducing the risk of HF hospitalization. However, concerns persist regarding potential adverse vascular effects, since iron may induce oxidative stress, inflammation, and apoptosis of endothelial cells. To assess endothelial health following ferric carboxymaltose (FCM) administration, we analyzed the profile of circulating endothelial microvesicles (EMVs) and endothelial progenitor cells (EPCs) in a cohort of 23 HF patients using flow cytometry. Compared to healthy subjects, baseline levels of CD31+/CD41- EMVs were higher and EMVs featured a more apoptotic phenotype in HF patients. Following FCM administration, EMV levels showed a rapid but transient increase and displayed an altered phenotype profile with dominant augmentation of EMVs expressing inducible markers CD62E and CD54, indicating endothelial inflammatory activation and injury. Levels of circulating vasoregenerative CD45lowCD34+KDR+ EPCs were lower in HF patients and FCM application resulted in an early decrease of EPCs followed by substantial mobilization into the circulation after one week. Levels of EMVs and EPCs returned to baseline values within two and four weeks, respectively. HF patients with additional chronic kidney disease showed an elevated EMV/EPC ratio and diminished EPC mobilization, suggesting impaired vascular repair capacity. Providing a mechanistic link, in vitro experiments with cultured endothelial cells revealed that FCM dose-dependently promotes endothelial apoptosis, increases expression of adhesion molecules and CXCL12, and triggers generation of EMVs. Intravenous iron supplementation with FCM in HF patients induces a biphasic response with initial increased release of CD62E+ and CD54+ enriched EMVs and subsequent mobilization of EPCs, indicating endothelial dysfunction upon FCM and suggesting consecutive engagement of a defense program aimed to reconstitute vascular health.

Pharmacological inhibition of protein tyrosine kinases axl and fyn reduces TNF-α-induced endothelial inflammatory activation in vitro.

Major surgery induces systemic inflammation leading to pro-inflammatory activation of endothelial cells. Endothelial inflammation is one of the drivers of postoperative organ damage, including acute kidney injury Tumour Necrosis Factor alpha (TNF-α) is an important component of surgery-induced pro-inflammatory activation of endothelial cells. Kinases, the backbone of signalling cascades, can be targeted by pharmacological inhibition. This is a promising treatment option to interfere with excessive endothelial inflammation. In this study, we identified activated kinases as potential therapeutic targets. These targets were pharmacologically inhibited to reduce TNF-α-induced pro-inflammatory signalling in endothelial cells. Kinome profiling using PamChip arrays identified 64 protein tyrosine kinases and 88 serine-threonine kinases, the activity of which was determined at various timepoints (5-240min) following stimulation with 10ng/ml TNF-α in Human umbilical vein endothelial cells in vitro. The PTKs Axl and Fyn were selected based on high kinase activity profiles. Co-localisation experiments with the endothelial-specific protein CD31 showed Axl expression in endothelial cells of glomeruli and Fyn in arterioles and glomeruli of both control and TNF-α-exposed mice. Pharmacological inhibition with Axl inhibitor BMS-777607 and Fyn inhibitor PP2 significantly reduced TNF-α-induced pro-inflammatory activation of E-selectin, VCAM-1, ICAM-1, IL-6 and IL-8 at mRNA and VCAM-1, ICAM-1, and IL-6 at protein level in HUVEC in vitro. Upon pharmacological inhibition with each inhibitor, leukocyte adhesion to HUVEC was also significantly reduced, however to a minor extent. In conclusion, pre-treatment of endothelial cells with kinase inhibitors BMS-777607 and PP2 reduces TNF-α-induced endothelial inflammation in vitro.

Endothelial inflammatory activation is related to myocardial perfusion disturbance in experimental chronic Chagas disease

Abstract Background Microvascular myocardial perfusion defect (MPD) is frequent in chronic Chagas cardiomyopathy (CCC) and may be involved in the pathophysiologic process that leads to left ventricular systolic dysfunction (LVSD). However, there is scarcity of studies addressing the histopathological meaning of MPD in CCC and its correlation with endothelial activation. Purpose To investigate the correlations between MPD detected in vivo with functional and histopathological changes in the experimental model of CCC in hamsters. Methods 24 female Sirius hamsters were investigated 8-months after intraperitoneal infection with 3.5x104 trypomastigote forms of Y-strain of T. cruzi. All animals were submitted to rest high-resolution 99mTc-Sestamibi-SPECT myocardial perfusion scintigraphy and echocardiography in vivo. The area of MPD was assessed through the calculation of polar maps by using a dedicated software (MunichHeart®) and a 13-segments model of LV. After euthanasia, we performed a histopathological study of cardiac inflammation and fibrosis and mRNA expression for TNF-α and ICAM, for assessment of inflammation and endothelial activation, respectively. Results Most of the animals presented MPD, n=17 (71%), its extension ranging from 1.4 to 30.3% of LV surface. We observed lower values of LVEF in animals with MPD (38.5±11.2%) when compared with animals without MPD 48.4±9.1%, p=0.04) and a trend to higher intensity of myocardial inflammation (estimated by the number of mononuclear cells) in animals with MPD (540.4±153.6 cell/mm2) vs. without MPD (409.6±130.3 cell/mm2), p=0.09. In addition, animals with MPD presented a higher ICAM (0.02±0.01) expression when compared with animals without MPD (0.01±0.01, p=0.02). There was no difference between groups regarding the extent of fibrosis. The results of the regression and correlation analysis showed that individual values of MPD area presented negative correlation with LVEF (R=−0.6, p=0.001), with echocardiographic wall motion score index (WMSi, R=0.5, p=0.007), and with the number of mononuclear cells (R=0.5, p=0.01). Moreover, an analysis based on myocardial segments (n=312), showed that segments with MPD (n=54) in comparison to those without MPD (n=258) presented higher number of mononuclear cells (608±299.9 cell/mm2 and 478.3±201.1 cell/mm, respectively, p&amp;lt;0.0001) and higher WMSi (1.8±0.9 and 1.2±0.4, respectively, p&amp;lt;0.0001. Conclusions MPD is a common finding in experimental model of CCC in hamsters and is correlated with inflammation, endothelial inflammatory activation, and systolic ventricular dysfunction. These results suggest that perfusion defects may be an in vivo surrogate marker for inflammation with potential translational implication for monitoring disease activity. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Fundação de Amparo à Pesquisa do Estado de São Paulo

Regulation of Atherosclerosis by Toll-Like Receptor 4 Induced by Serum Amyloid 1: A Systematic In Vitro Study.

The objective of this study was to investigate the effects of serum amyloid 1 (SAA1) on activation of endothelial cells, formation of foam cells, platelet aggregation, and monocyte/platelet adhesion to endothelial cells. The effect of SAA1 on the inflammatory activation of endothelial cells was investigated by detecting the expression of inflammatory factors and adhesion molecules. The role of SAA1 in formation of foam cells was verified by detecting lipid deposition and expression of molecules related to the formation of foam cells. After platelets were stimulated by SAA1, the aggregation rate was evaluated to determine the effect of SAA1 on platelet aggregation. Monocytes/platelets were cocultured with human umbilical vein endothelial cells (HUVECs) pretreated with or without SAA1 to determine whether SAA1 affected monocyte/platelet adhesion to endothelial cells. By inhibiting toll-like receptor 4 (TLR4) function, we further identified the role of TLR4 signaling in SAA1-mediated endothelial inflammatory activation, foam-cell formation, and monocyte/platelet adhesion to HUVECs. SAA1 significantly increased the expression of adhesion molecules and inflammatory factors in HUVECs. Moreover, SAA1 also promoted lipid deposition and the expression of inflammatory factors and low-density lipoprotein receptor-1 (LOX-1) in THP-1-derived macrophages. In addition, SAA1 induced platelet aggregation and enhanced monocyte/platelet adhesion to HUVECs. However, the TLR4 antagonist significantly inhibited SAA1-induced endothelial cell activation, foam-cell formation, and monocyte/platelet adhesion to HUVECs and downregulated the expression of myeloid differentiation factor 88 (MyD88), phosphor-inhibitor of nuclear factor κB kinase subunit α/β (P-IKKα/β), phospho-inhibitor of nuclear factor κB subunit α (P-IKBα), and phosphorylation of nuclear transcription factor-κB p65 (P-p65) in SAA1-induced HUVECs and THP-1 cells. Conclusively, it is speculated that SAA1 promotes atherosclerosis through enhancing endothelial cell activation, platelet aggregation, foam-cell formation, and monocyte/platelet adhesion to endothelial cells. These biological functions of SAA1 may depend on the activation of TLR4-related nuclear factor-kappa B (NF-κB) signaling pathway.

Abstract 285: Organ chip culture of vascularized triple negative breast cancer explant tissues with validated pathological and clinically-targetable properties of tumor vasculature

Abstract Triple negative breast cancer (TNBC) is an aggressive subtype characterized by a lack of the classic targetable receptors. Targeting the TNBC microenvironment via the biophysical properties of the tumor vasculature is a promising approach. The objective of this study was to engineer a microphysiological model of vascularized TNBC with validated pathological properties of tumor vasculature for in vitro modeling of selective drug delivery via the enhanced permeability and retention effect. We engineered a method for standardized production of milliscale tissues housed in fluidic culture devices that are accessible only via a fully anastomosed and perfusable internal vasculature comprised of endothelial cells and organ specific fibroblasts. We first established a baseline of vascular morphometry, endothelial barrier function, inflammatory activation, and perivascular extracellular matrix (ECM) composition in vascularized tissues devoid of cancer cells. In parallel, we developed a novel approach for processing patient-derived TNBC tissues into injectable explants of disaggregated tumor imbibed in ECM hydrogel in less than one hour. These explant tissues cultured in our devices consistently maintain high viability and a Ki67 index around 70%, on par with the Ki67 indexes of source TNBC tumors. We hypothesized that TNBC derivatives would induce the formation of a pathological vasculature in our model. The TNBC derivatives were mixed with exogenous fibroblasts and endothelial cells at optimized ratios and the same workflow described above was used to form vascularized TNBC explant tissues. TNBC-associated vasculature exhibited a significantly altered vascular morphometry relative to cancer-free control tissues across multiple quantitative metrics including vessel length, vessel diameter, and network branch points. These morphological changes were consistent with known dysmorphic features of tumor vasculature. Twofold or greater increases in endothelial ICAM-1 expression in TNBC-associated vasculature was measured by multiple methods of analysis. Increased inflammatory adhesion molecule expression was accompanied by disorganized VE-cadherin junctions and disrupted patterns of perivascular cell coverage that suggested TNBC-associated vasculature should be significantly more permeable. FITC-dextran perfusion studies revealed widespread macromolecular leakage from TNBC-associated vasculature into the TNBC explant tissue interstitium by 5 minutes, whereas no leakage was observed from control vasculature for the duration of perfusion up to one hour. Ongoing work to be presented is focused on validating our model as a platform for studying drug delivery via the enhanced permeability and retention effect using Abraxane nanoparticles. Citation Format: Kevin M. Conrad, Charles E. Byrne, Matthew R. Burow, Mark Mondrinos. Organ chip culture of vascularized triple negative breast cancer explant tissues with validated pathological and clinically-targetable properties of tumor vasculature [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 285.

Unlocking the Untapped Potential of Endothelial Kinase and Phosphatase Involvement in Sepsis for Drug Treatment Design.

Sepsis is a devastating clinical condition that can lead to multiple organ failure and death. Despite advancements in our understanding of molecular mechanisms underlying sepsis and sepsis-associated multiple organ failure, no effective therapeutic treatment to directly counteract it has yet been established. The endothelium is considered to play an important role in sepsis. This review highlights a number of signal transduction pathways involved in endothelial inflammatory activation and dysregulated endothelial barrier function in response to sepsis conditions. Within these pathways – NF-κB, Rac1/RhoA GTPases, AP-1, APC/S1P, Angpt/Tie2, and VEGF/VEGFR2 – we focus on the role of kinases and phosphatases as potential druggable targets for therapeutic intervention. Animal studies and clinical trials that have been conducted for this purpose are discussed, highlighting reasons why they might not have resulted in the expected outcomes, and which lessons can be learned from this. Lastly, opportunities and challenges that sepsis and sepsis-associated multiple organ failure research are currently facing are presented, including recommendations on improved experimental design to increase the translational power of preclinical research to the clinic.

Uterine Microvascular Dysfunction After Plastic Particle Inhalation

Adverse cardiovascular and inflammatory outcomes after airborne particulate matter (PM) inhalation have long been a topic of epidemiological studies. Previous studies have identified, the microcirculation as particularly vulnerable to this insult. However, the mechanisms of microvascular dysfunction are complex and vary with each specific aerosol. Variations in neurohormonal and inflammatory status contribute to the complexity of defining mechanisms of microvascular dysfunction caused by aerosols. Given the recent identification and toxicological concerns surrounding micro‐ and nanoplastic exposures, we aimed to evaluate microvascular reactivity after acute plastic particle inhalation in this study. Virgin female Sprague Dawley rats in estrus were exposed to filtered air or aerosolized polyamide (i.e., nylon) particles in a whole‐body inhalation chamber. We hypothesized the uterine microvascular reactivity would achieve a vasoconstrictive state due to plastic particle inhalation. Exposure only during estrus served to control for neurohormonal differences within groups. 24h later, the radial arteriole of the uterus was selected as a representative vessel for the microcirculation. Ex vivouterine radial arteriole reactivity was assessed using pressure myography Living Systems Instrumentation, St. Albans, VT). Vascular reactivity was assessed based on responses to endothelium‐dependent (methacholine, MCh, 10‐9‐10‐4 M), –independent (sodium nitroprusside, SNP, 10‐9‐10‐4 M), and smooth muscle contractility (phenylephrine, PE, 10‐9‐10‐4 M). Inflammatory cytokines (IL‐4, IL‐6, MCP‐1, CXCL1; Sigma, St. Louis, MO and IL 5; Abcam, Cambridge, UK) were quantified in plasma with ELISA. Acute inhalation exposure to polyamide MNPs led to significantly impaired vascular reactivity through endothelium‐dependent and vascular smooth muscle mechanisms. Percent maximum dilation in response to 10‐9 M MCh was significantly reduced in exposed animals when compared to controls (‐9.44% ± 3.65 vs. 7.26% ± 4.61). Smooth muscle contraction was also impaired with percent maximum dilation in response to 10‐8 M PE being significantly increased in exposed animals compared to controls (‐9.56%±7.28 vs. ‐59.7±17.4). The levels of IL‐6 were not significant between groups which suggests systemic inflammation may not be a key component of plastic aerosol induced vascular dysfunction. In summary, exposure to polyamide MNPs resulted in less vascular reactivity to pharmacologic stimuli during estrus. However, the mechanisms attributing to disrupted microvascular function remain elusive. An important consideration for future studies will be the proper time point in which various cytokines can be assessed and the reproductive ramifications of these findings. Future studies should examine the impact of plastic particulate inhalation on endothelial inflammatory activation, metabolism, or apoptotic mechanisms. Altogether this information may give insight into how plastic particle inhalation could impair distal tissue health, including endometrial perfusion and ability to sustain pregnancy.

High circulating levels of CD62E+ and CD31+/Annexin V+ endothelium-derived microparticles in children with overweight/obesity: Evidence of early vascular damage

BackgroundObesity perturbs endothelium integrity, leading to endothelial activation, which predisposes the release of endothelium-derived microparticles (EMP). We measured the CD31+/annexin V+ and CD62E+ EMP levels to improve our understanding of their contribution to endothelial damage in children with overweight/obesity. Subject and methodsIn this cross-sectional study, 107 children with normal weight and 35 children with overweight/obesity were evaluated. Anthropometric measurement, blood pressure, biochemical profile was performed. Standardized flow cytometry methods were used to identify and quantify circulating CD31+/annexin V+ and CD62E+ EMP. ResultsChildren with overweight/obesity had significantly higher circulating levels of CD31+/annexin V+ (750 [600]) and CD62E+ (1400 [700]) EMP than those with normal weight (P < 0.001 for both). We found that EMP levels were positively correlated with body mass index (BMI), waist circumference, blood pressure, total cholesterol, low-density lipoprotein cholesterol (LDLc), and triglycerides. The multivariable logistic regression model revealed that the risks of having high EMP levels (> 75th percentile) were high in children with both large waist circumference and elevated LDLc level. Receiver operating characteristic (ROC) curves demonstrated that the LDLc levels showed significantly greater discrimination than waist circumference for both CD31+/annexin V+ (P = 0.031) as CD62E+ EMPs (P = 0.041). ConclusionsChildren with overweight/obesity have high circulating CD31+/annexin V+ and CD62E+ EMP levels, which may be an early sign of endothelial apoptosis and inflammatory activation in response to injury. These EMP levels were positively associated with several cardiometabolic risk factors. Our data underscore the negative influence of high-risk metabolic profiles on endothelial integrity in the early stages of childhood obesity.

Cooperation between CYB5R3 and NOX4 via coenzyme Q mitigates endothelial inflammation

NADPH oxidase 4 (NOX4) regulates endothelial inflammation by producing hydrogen peroxide (H2O2) and to a lesser extent O2•-. The ratio of NOX4-derived H2O2 and O2•- can be altered by coenzyme Q (CoQ) mimics. Therefore, we hypothesize that cytochrome b5 reductase 3 (CYB5R3), a CoQ reductase abundant in vascular endothelial cells, regulates inflammatory activation. To examine endothelial CYB5R3 in vivo, we created tamoxifen-inducible endothelium-specific Cyb5r3 knockout mice (R3 KO). Radiotelemetry measurements of systolic blood pressure showed systemic hypotension in lipopolysaccharides (LPS) challenged mice, which was exacerbated in R3 KO mice. Meanwhile, LPS treatment caused greater endothelial dysfunction in R3 KO mice, evaluated by acetylcholine-induced vasodilation in the isolated aorta, accompanied by elevated mRNA expression of vascular adhesion molecule 1 (Vcam-1). Similarly, in cultured human aortic endothelial cells (HAEC), LPS and tumor necrosis factor α (TNF-α) induced VCAM-1 protein expression was enhanced by Cyb5r3 siRNA, which was ablated by silencing the Nox4 gene simultaneously. Moreover, super-resolution confocal microscopy indicated mitochondrial co-localization of CYB5R3 and NOX4 in HAECs. APEX2-based electron microscopy and proximity biotinylation also demonstrated CYB5R3's localization on the mitochondrial outer membrane and its interaction with NOX4, which was further confirmed by the proximity ligation assay. Notably, Cyb5r3 knockdown HAECs showed less total H2O2 but more mitochondrial O2•-. Using inactive or non-membrane bound active CYB5R3, we found that CYB5R3 activity and membrane translocation are needed for optimal generation of H2O2 by NOX4. Lastly, cells lacking the CoQ synthesizing enzyme COQ6 showed decreased NOX4-derived H2O2, indicating a requirement for endogenous CoQ in NOX4 activity. In conclusion, CYB5R3 mitigates endothelial inflammatory activation by assisting in NOX4-dependent H2O2 generation via CoQ.

Vascular and metabolic effects of SGLT2i and GLP-1 in heart failure patients.

Alterations of endothelial function, inflammatory activation, and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway are involved in the pathophysiology of heart failure. Metabolic alterations have been studied in the myocardium of heart failure (HF) patients; alterations in ketone body and amino acid/protein metabolism have been described in patients affected by HF, as well as mitochondrial dysfunction and other modified metabolic signaling. However, their possible contributions toward cardiac function impairment in HF patients are not completely known. Recently, sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) have emerged as a new class of drugs designed to treat patients with type 2 diabetes (T2D), but have also been shown to be protective against HF-related events and CV mortality. To date, the protective cardiovascular effects of these drugs in patients with and without T2D are not completely understood and several mechanisms have been proposed. In this review, we discuss on vascular and metabolic effects of SGLT2i and GLP-1 in HF patients.

HA and HS Changes in Endothelial Inflammatory Activation.

Cardiovascular diseases are a group of disorders caused by the presence of a combination of risk factors, such as tobacco use, unhealthy diet and obesity, physical inactivity, etc., which cause the modification of the composition of the vessel’s matrix and lead to the alteration of blood flow, matched with an inflammation condition. Nevertheless, it is not clear if the inflammation is a permissive condition or a consequent one. In order to investigate the effect of inflammation on the onset of vascular disease, we treated endothelial cells with the cytokine TNF-α that is increased in obese patients and is reported to induce cardiometabolic diseases. The inflammation induced a large change in the extracellular matrix, increasing the pericellular hyaluronan and altering the heparan sulfate Syndecans sets, which seems to be related to layer permeability but does not influence cell proliferation or migration nor induce blood cell recruitment or activation.

The Endothelium as a Target for Anti-Atherogenic Therapy: A Focus on the Epigenetic Enzymes EZH2 and SIRT1.

Endothelial cell inflammatory activation and dysfunction are key events in the pathophysiology of atherosclerosis, and are associated with an elevated risk of cardiovascular events. Yet, therapies specifically targeting the endothelium and atherosclerosis are lacking. Here, we review how endothelial behaviour affects atherogenesis and pose that the endothelium may be an efficacious cellular target for antiatherogenic therapies. We discuss the contribution of endothelial inflammatory activation and dysfunction to atherogenesis and postulate that the dysregulation of specific epigenetic enzymes, EZH2 and SIRT1, aggravate endothelial dysfunction in a pleiotropic fashion. Moreover, we propose that commercially available drugs are available to clinically explore this postulation.

COVID-19-induced endotheliitis: emerging evidence and possible therapeutic strategies.

The coronavirus disease 2019 (COVID‐19) pandemic, a viral illness caused by the severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), 1 has produced at the time of this writing nearly 33 million cases of infection, with over a million deaths in 235 countries, 2 causing an unprecedented burden on healthcare systems and a severe global socioeconomic crisis. As the pandemic spreads, knowledge on the disease course, as well as potential risk factors and predictors of severity is increasing daily, and initial data from randomised controlled studies have allowed care providers to refine therapeutic strategies. Nonetheless, mortality is markedly elevated among those presenting with severe disease, long‐term sequelae among survivors are unknown, and vaccine‐based therapies currently remain at early stages of development. Most reported cases are asymptomatic or present with mild symptoms; however, 7–26% of hospitalised patients experience severe disease, often requiring admission to intensive care units (ICUs), with progressive multiple organ dysfunction and high mortality. 3 , 4 , 5 Such differences in clinical outcomes have led physicians to initiate diverse pharmacological therapies at various stages of the disease, generating challenges as to the most appropriate therapeutic choice for COVID‐19. In this context, the use of dexamethasone has significantly reduced mortality rates in critically ill patients requiring supplemental oxygen or mechanical ventilation, 6 and remdesivir has demonstrated clinical benefit in hospitalised patients, but with unknown survival benefit to date 7 ; additional effective treatment options are therefore urgently needed. In an initial attempt to provide a uniform and widely reproducible methodology to guide systematic treatment strategies, a three‐stage classification of COVID‐19 has been proposed. 8 The Stage I or ‘early infection’ occurs at the initial establishment of disease with high viral replication, and commonly presents with a range of complaints that can include mild and often non‐specific influenza‐like signs and symptoms. Stage II is the ‘pulmonary phase’, with preferential viral‐mediated injury of the lung parenchyma and this is characterised by shortness of breath, hypoxia and pulmonary infiltrates with some degree of lung inflammation. Stage III is characterised by an exaggerated host immune‐inflammatory response to the virus, leading to acute respiratory distress syndrome (ARDS) and multi‐organ failure (MOF).