Endothelial cells overexpressing interleukin-8 receptors reduce inflammatory and neointimal responses to arterial injury

Regulation of MMP-2 by IL-8 in Vascular Endothelial Cells: Probable Mechanism for Endothelial Dysfunction in Women with Preeclampsia

Endothelial dysfunction (ED) in preeclampsia (PE) results from the convergence of oxidative stress, inflammation, and alterations in extracellular matrix components, affecting vascular tone and permeability. The molecular network leading to ED includes IL-8 and MMP-2. In vitro, IL-8 regulates the concentration and activity of MMP-2 in the trophoblast; this interaction has not been studied in endothelial cells during PE. We isolated human umbilical vein endothelial cells (HUVECs) from women with healthy pregnancies (NP, n = 15) and PE (n = 15). We quantified the intracellular concentration of nitric oxide and reactive oxygen species with colorimetric assays, IL-8 with ELISA, and MMP-2 with zymography and using an ELISA-type system. An IL-8 inhibition assay was used to study the influence of this cytokine on MMP-2 concentration and activity. HUVECs from women with PE showed significantly higher oxidative stress than NP. IL-8 and MMP-2 were found to be significantly elevated in PE HUVECs compared to NP. Inhibition of IL-8 in HUVECs from women with PE significantly decreased the concentration of MMP-2. We demonstrate that IL-8 is involved in the mechanisms of MMP-2 expression in HUVECs from women with PE. Our findings provide new insights into the molecular mechanisms regulating the ED distinctive of PE.

Cytokines and their role in cardiovascular diseases

The evaluation of diagnostic and prognostic biomarkers has always been a hot topic in various diseases. Considering that cardiovascular diseases (CVDs) have the highest mortality and morbidity rates in the world, various studies have been conducted so far to find CVD associated biomarkers, including cardiac troponin (cTn) and NT-proBNP. Cytokines are components of the immune system that are involved in the pathogenesis of CVD due to their contribution to the inflammation process. The level of cytokines varies in many cardiovascular diseases. For instance, the plasma level of IL-1α, IL-18, IL-33, IL-6 and IL-8 is positively correlated with atherosclerosis and that of some other interleukins such as IL-35 is negatively correlated with acute myocardial infarction or cardiac angina. Due to its pivotal role in the inflammation process, IL-1 super family is involved in many CVDs, including atherosclerosis. IL-20 among the interleukins of IL-10 family has a pro-atherogenic role, while others, such as IL-10 and IL-19, play an anti-atherogenic role. In the present review, we have collected the latest published evidence in this respect to discuss valuable cytokines from the diagnostic and prognostic stand point in CVDs.

Endothelial cells overexpressing CXCR1/2 are renoprotective in rats with acute kidney injury

Inflammation that develops with the release of chemokines and cytokines during acute kidney injury (AKI) has been shown to participate in functional renal recovery. Although a major research focus has been on the role of macrophages, the family of C-X-C motif chemokines that promote neutrophil adherence and activation also increases with kidney ischemia-reperfusion (I/R) injury. This study tested the hypothesis that intravenous delivery of endothelial cells (ECs) that overexpress (C-X-C motif) chemokine receptors 1 and 2 (CXCR1 and CXCR2, respectively) improves outcomes in kidney I/R injury. Overexpression of CXCR1/2 enhanced homing of endothelial cells to I/R-injured kidneys and limited interstitial fibrosis, capillary rarefaction, and tissue injury biomarkers (serum creatinine concentration and urinary kidney injury molecule-1) following AKI and also reduced expression of P-selectin and the rodent (C-X-C motif) chemokine cytokine-induced neutrophil chemoattractant (CINC)-2β as well as the number of myeloperoxidase-positive cells in the postischemic kidney. The serum chemokine/cytokine profile, including CINC-1, showed similar reductions. These findings were not observed in rats given endothelial cells transduced with an empty adenoviral vector (null-ECs) or a vehicle alone. These data indicate that extrarenal endothelial cells that overexpress CXCR1 and CXCR2, but not null-ECs or vehicle alone, reduce I/R kidney injury and preserve kidney function in a rat model of AKI.NEW & NOTEWORTHY Inflammation facilitates kidney ischemia-reperfusion (I/R) injury. Endothelial cells (ECs) that were modified to overexpress (C-X-C motif) chemokine receptor (CXCR)1/2 (CXCR1/2-ECs) were injected immediately following kidney I/R injury. The interaction of CXCR1/2-ECs, but not ECs transduced with an empty adenoviral vector, with injured kidney tissue preserved kidney function and reduced production of inflammatory markers, capillary rarefaction, and interstitial fibrosis. The study highlights a functional role for the C-X-C chemokine pathway in kidney damage following I/R injury.

Pharmacological inhibition of the lipid phosphatase PTEN ameliorates heart damage and adipose tissue inflammation in stressed rats with metabolic syndrome

Phosphatidylinositol 3-kinase (PI3K) signaling promotes the differentiation and proliferation of regulatory B (Breg) cells, and the lipid phosphatase phosphatase and tensin homolog deleted on chromosome 10 (PTEN) antagonizes the PI3K-Akt signaling pathway. We previously demonstrated that cardiac Akt activity is increased and that restraint stress exacerbates hypertension and both heart and adipose tissue (AT) inflammation in DS/obese rats, an animal model of metabolic syndrome (MetS). We here examined the effects of restraint stress and pharmacological inhibition of PTEN on heart and AT pathology in such rats. Nine-week-old animals were treated with the PTEN inhibitor bisperoxovanadium-pic [bpV(pic)] or vehicle in the absence or presence of restraint stress for 4 weeks. BpV(pic) treatment had no effect on body weight or fat mass but attenuated hypertension in DS/obese rats subjected to restraint stress. BpV(pic) ameliorated left ventricular (LV) inflammation, fibrosis, and diastolic dysfunction as well as AT inflammation in the stressed rats. Restraint stress reduced myocardial capillary density, and this effect was prevented by bpV(pic). In addition, bpV(pic) increased the proportions of Breg and B-1 cells as well as reduced those of CD8+ T and B-2 cells in AT of stressed rats. Our results indicate that inhibition of PTEN by bpV(pic) alleviated heart and AT inflammation in stressed rats with MetS. These positive effects of bpV(pic) are likely due, at least in part, to a reduction in blood pressure, an increase in myocardial capillary formation, and an altered distribution of immune cells in fat tissue that result from the activation of PI3K-Akt signaling.

Carbon Nanodots Inhibit Oxidized Low Density Lipoprotein-Induced Injury and Monocyte Adhesion to Endothelial Cells Through Scavenging Reactive Oxygen Species

Oxidized low density lipoprotein (Ox-LDL) is a known biomarker of inflammation and atherosclerosis, a leading cause of death worldwide. As a new class of nanomaterials, carbon nanodots (CNDs) are widely used in bioimaging, diagnostics, and drug delivery. However, there is no current report on how these CNDs affect the cardiovascular system, particularly their potential in mediating endothelial inflammatory dysfunction. This study examined effects of CNDs on Ox-LDL-mediated endothelial dysfunction. CNDs significantly inhibited Ox-LDL-mediated adhesion of monocytes to human microvascular endothelial cells (HMEC-1), in human microvascular endothelial cells (HMEC-1). CNDs significantly inhibited Ox-LDL-mediated adhesion of monocytes to endothelial cells, which is an essential step in the development of atherosclerosis. Further, CNDs significantly inhibited OxLDL-induced expression of interleukin-8 (IL-8), a vital cytokine on monocyte adhesion to the endothelial cells. These results demonstrate CNDs possess anti-inflammatory properties. CNDs also protect cells against Ox-LDL-induced cytotoxicity. Electron paramagnetic resonance (EPR) spectroscopy studies demonstrated direct reactive oxygen species-scavenging by CNDs. This result indicates that the anti-inflammatory properties of CNDs are most likely due to their direct scavenging of reactive oxygen species. Animal studies involving mice did not show any morphological or physical changes between the CNDs and control groups. Our study provides evidence of potential of CNDs in reducing Ox-LDL-mediated inflammation and cytotoxicity in HMEC-1.

Eva1a ameliorates atherosclerosis by promoting re-endothelialization of injured arteries via Rac1/Cdc42/Arpc1b

AIMS

Eva-1 homologue 1 (Eva1a) is a novel protein involved in the regulation of cardiac remodelling and plaque stability, but little is known about its role in re-endothelialization and the development of atherosclerosis (AS). Thus, in the present study, we aimed to elucidate the function of Eva1a in re-endothelialization and AS.

METHODS AND RESULTS

Wire injuries of carotid and femoral arteries were established in Eva1a-/- mice. Eva1a-deficient mice were crossed with apolipoprotein E-/- (ApoE-/-) mice to evaluate AS development and re-endothelialization of carotid artery injuries. Denudation of the carotid artery at 3, 5, and 7 days was significantly aggravated in Eva1a-/- mice. The neointima of the femoral artery at 14 and 28 days was consequently exacerbated in Eva1a-/- mice. The area of atherosclerotic lesions was increased in Eva1a-/-ApoE-/- mice. To explore the underlying mechanisms, we performed transwell, scratch migration, cell counting kit-8, and bromodeoxyuridine assays using cultured human aorta endothelial cells (HAECs), which demonstrated that EVA1A promoted HAEC migration and proliferation. Proteomics revealed that the level of actin-related protein 2/3 complex subunit 1B (Arpc1b) was decreased, while Eva1a expression was absent. Arpc1b was found to be a downstream molecule of EVA1A by small interfering RNA transfection assay. Activation of Rac1 and Cdc42 GTPases was also regulated by EVA1A.

CONCLUSION

This study provides insights into anti-atherogenesis effects of Eva1a by promoting endothelium repair. Thus, Eva1a is a promising therapeutic target for AS.

Induced pluripotent stem cells attenuate chronic allogeneic vasculopathy in an integrin beta-1-dependent manner

This study aimed to determine the mechanism of isogeneic-induced pluripotent stem cells (iPSCs) homing to vascular transplants and their therapeutic effect on chronic allogeneic vasculopathy. We found that integrin β1 (Intgβ1) was the dominant integrin β unit in iPSCs that mediates the adhesion of circulatory and endothelial cells (ECs). Intgβ1 knockout or Intgβ1-siRNAs inhibit iPSC adhesion and migration across activated endothelial monolayers. The therapeutic effects of the following were examined: iPSCs, Intgβ1-knockout iPSCs, iPSCs transfected with Intgβ1-siRNAs or nontargeting siRNAs, iPSC-derived ECs, iPSC-derived ECs simultaneously overexpressing Intgα4 and Intgβ1, iPSCs precultured in endothelial medium for 3 days (endothelial-prone stem cells), primary aortic ECs, mouse embryonic fibroblasts, and phosphate-buffered saline (control). The cells were administered every 3 days for a period of 8 weeks. iPSCs, iPSCs transfected with nontargeting siRNAs, and endothelial-prone stem cells selectively homed on the luminal surface of the allografts, differentiated into ECs, and decreased neointimal proliferation. Through a single administration, we found that iPSCs trafficked to allograft lesions, differentiated into ECs within 1 week, and survived for 4-8 weeks. The therapeutic effect of a single administration was moderate. Thus, Intgβ1 and pluripotency are essential for iPSCs to treat allogeneic vasculopathy.

Ischemic Stroke among the Symptoms Caused by the COVID-19 Infection

The 2019 global pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been declared a public health emergency of international concern by the World Health Organization (WHO). The WHO recognized the spread of COVID-19 as a pandemic on 11 March 2020. Based on statistics from 10 August 2020, more than 20.2 million cases of COVID-19 have been reported resulting in more than 738,000 deaths. This completely new coronavirus has spread worldwide in a short period, causing economic crises and healthcare system failures worldwide. Initially, it was thought that the main health threat was associated with respiratory system failures, but since then, SARS-CoV-2 has been linked to a broad spectrum of symptoms indicating neurological manifestations, including ischemic stroke. Current knowledge about SARS-CoV-2 and its complications is very limited because of its rapidly evolving character. However, further research is undoubtedly necessary to understand the causes of neurological abnormalities, including acute cerebrovascular disease. The viral infection is inextricably associated with the activation of the immune system and the release of pro-inflammatory factors, that can stimulate the host organism to defend itself. However, the body’s immune response is a double-edged sword that on one hand, destroys the virus but also disrupts the homeostasis leading to serious complications, including thrombosis. Numerous studies have linked coagulopathies with COVID-19, however, there is great uncertainty regarding it functions on the molecular level. In this review, a detailed insight into the biological processes associated with ischemic stroke in COVID-19 patients and suggest a possible explanation for this phenomenon is provided.

Endothelial cells and angiogenesis in the horse in health and disease-A review

The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progenitor cells; equine endothelial cells and angiogenesis (heterogeneity, markers and assessment); endothelial regulatory molecules in equine angiogenesis; angiogenesis research in equine reproduction (ovary, uterus, placenta and conceptus, testis); angiogenesis research in pathological conditions (tumours, ocular pathologies, equine wound healing, musculoskeletal system and laminitis). The review also includes a table that summarizes in vitro studies on equine endothelial cells, either describing the isolation procedure or using previously isolated endothelial cells. A particular challenge of the review was that results published are fragmentary and sometimes even contradictory, raising more questions than they answer. In conclusion, angiogenesis is a major factor in several diseases frequently occurring in horses, but relatively few studies focus on angiogenesis in the horse. The challenge for the future is therefore to continue exploring new therapeutic angiogenesis strategies for horses to fill in the missing pieces of the puzzle.

Induced pluripotent stem cell-derived endothelial cells attenuate lipopolysaccharide-induced acute lung injury

The chemokine receptors CXCR1/2 and CCR2/5 play a critical role in neutrophil and monocyte recruitment to sites of injury and/or inflammation. Neutrophil-mediated inflammation and endothelial cell (EC) injury are unifying factors in the pathogenesis of the acute respiratory distress syndrome. This study tested the hypothesis that systemic administration of rat-induced pluripotent stem cell (iPS)-derived ECs (iPS-ECs) overexpressing CXCR1/2 or CCR2/5 attenuates lipopolysaccharide (LPS)-induced acute lung injury. Rat iPS-ECs were transduced with adenovirus containing cDNA of CXCR1/2 or CCR2/5. Ovariectomized Sprague-Dawley rats (10 wk old) received intraperitoneal injection of LPS and intravenous infusion of 1) saline vehicle, 2) AdNull-iPS-ECs (iPS-ECs transduced with empty adenoviral vector), 3) CXCR1/2-iPS-ECs (iPS-ECs overexpressing CXCR1/2), or 4) CCR2/5-iPS-ECs (iPS-ECs overexpressing CCR2/5) at 2 h post-LPS. Rats receiving intraperitoneal injection of saline served as sham controls. Later (4 h), proinflammatory cytokine/chemokine mRNA and protein levels were measured in total lung homogenates by real-time RT-PCR and Luminex multiplex assays, and neutrophil and macrophage infiltration in alveoli was measured by immunohistochemical staining. Pulmonary microvascular permeability was assessed by the Evans blue technique, and pulmonary edema was estimated by wet-to-dry lung weight ratios. Albumin levels and neutrophil counts were assessed in bronchoalveolar lavage fluid at 24 h post-LPS. Both CXCR1/2-iPS-ECs and CCR2/5-iPS-ECs significantly reduced LPS-induced proinflammatory mediator expression, neutrophil and macrophage infiltration, pulmonary edema, and vascular permeability compared with controls. These provocative findings provide strong evidence that targeted delivery of iPS-ECs overexpressing CXCR1/2 or CCR2/5 prevents LPS-induced acute lung injury.NEW & NOTEWORTHY We have developed a novel approach to address neutrophil-mediated inflammation and endothelial damage by targeted delivery of rat-induced pluripotent stem cell (iPS)-derived endothelial cell (ECs)overexpressing chemokine receptors CXCR1/2 and CCR2/5 in injured lung tissue in a model of acute lung injury. We have demonstrated that intravenously transfused CXCR1/2-iPS-ECs and CCR2/5-iPS-ECs are recruited to lipopolysaccharide-injured lungs and attenuate lipopolysaccharide-induced parenchymal lung injury responses, including inflammatory mediator expression, inflammatory cell infiltration, and vascular leakage compared with controls.

T helper type cytokines in sepsis: time-shared variance and correlation with organ dysfunction and hospital mortality

Objective

We evaluated the kinetics of cytokines belonging to the T helper1 (Th1), Th2, and Th17 profiles in septic patients, and their correlations with organ dysfunction and hospital mortality.

Methods

This was a prospective observational study in a cohort of septic patients admitted to the intensive care units (ICU) of three Brazilian general hospitals. A total of 104 septic patients and 53 health volunteers (controls) were included. Plasma samples were collected within the first 48 h of organ dysfunction or septic shock (0D), after seven (D7) and 14 days (D14) of follow-up. The following cytokines were measured by flow cytometry: Interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-10, IL-12/23p40, IL-17, IL-21, tumor necrosis factor-α (TNF-α), granulocyte-macrophage colony stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF).

Results

IL-6, IL-8, G-CSF and IL-10 concentrations were higher in septic patients than in controls (p < 0.001), while IL-12/23p40 presented higher levels in the controls (p = 0.003). IL-6, IL-8 and IL-17 correlated with Sequential [Sepsis-related] Organ Failure Assessment (SOFA) D0, D1 and D3 (except for IL-6 at D0). IL-8 was associated with renal and cardiovascular dysfunction. In a mixed model analysis, IL-10 estimated means were lower in survivors than in deceased (p = 0.014), while IL-21 had an estimated mean of 195.8 pg/mL for survivors and 98.5 for deceased (p = 0.03). Cytokines were grouped in four factors according to their kinetics over the three dosages (D0, D7, D14). Group 1 encompassed IL-6, IL-8, IL-10, IL-1β, and G-CSF while Group 3 encompassed IL-17 and IL-12/23p40. Both correlated with SOFA (D0) (p = 0.039 and p = 0.003, respectively). IL-21 (Group 4) was higher in those who survived. IL-2, TNF-α and GM-CSF (Group 2) showed no correlation with outcomes.

Conclusion

Inflammatory and anti-inflammatory cytokines shared co-variance in septic patients and were related to organ dysfunctions and hospital mortality.

Blocking the REDD1/TXNIP axis ameliorates LPS-induced vascular endothelial cell injury through repressing oxidative stress and apoptosis

The aim of the present study was to investigate the potential role of regulated in development and DNA damage response 1 (REDD1) in LPS-induced vascular endothelial injury by using human umbilical vein endothelial cells (HUVECs). We observed that REDD1 expression was apparently elevated in HUVECs after exposure to LPS. Additionally, elimination of REDD1 strikingly attenuated the secretion of the proinflammatory cytokines TNF-α, IL-6, IL-1β, and monocyte chemotactic protein-1 and the endothelial cell adhesion markers ICAM-1 and VCAM-1 that was induced by LPS stimulation. Subsequently, knockdown of REDD1 augmented cell viability but ameliorated lactate dehydrogenase release in HUVECs stimulated with LPS. Meanwhile, depletion of REDD1 effectively restricted LPS-induced HUVEC apoptosis, as exemplified by reduced DNA fragmentation, and it also elevated antiapoptotic Bcl-2 protein, concomitant with reduced levels of proapoptotic proteins Bax and cleaved caspase-3. Furthermore, repression of REDD1 remarkably alleviated LPS-triggered intracellular reactive oxygen species generation accompanied by decreased malondialdehyde content and increased the activity of the endogenous antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase. Most important, depletion of REDD1 protected HUVECs against inflammation-mediated apoptosis and oxidative damage partly through thioredoxin-interacting protein (TXNIP). Collectively, these findings indicate that blocking the REDD1/TXNIP axis repressed the inflammation-mediated vascular injury process, which may be closely related to oxidative stress and apoptosis in HUVECs, implying that the REDD1/TXNIP axis may be a new target for preventing the endothelial cell injury process.

Interferon-induced protein 35 inhibits endothelial cell proliferation, migration and re-endothelialization of injured arteries by inhibiting the nuclear factor-kappa B pathway

AIM

Endothelial recovery, or re-endothelialization, plays an important role in intimal hyperplasia and atherosclerosis after endothelial injury. Studying the mechanisms of re-endothelialization and strategies to promote efficient endothelial recovery are still needed. Interferon-induced protein 35 (IFI35) is an IFN-γ-induced protein that plays important roles in the antivirus-related immune-inflammatory response. In this study, we tested whether overexpression IFI35 affects the proliferation and migration of endothelial cells (ECs) and re-endothelialization.

METHODS

Wire injury of the carotid artery was induced in C57BL/6 mice, which was followed by IFI35 or null adenovirus transduction. Evans blue staining and HE staining were performed to evaluate the re-endothelialization rate and neointima formation. In vitro studies, primary human umbilical vein endothelial cells (HUVECs) were transfected with Ad-IFI35 or siRNA-IFI35 to evaluate its potential roles in cell proliferation and migration. Furthermore, the potential mechanism relating inhibition of NF-κB/p65 pathway was elaborated by luciferase assay and IFI35 domain deletion assay.

RESULTS

In IFI35 adenovirus-transduced mice, the re-endothelialization rates at days 3, 7 were significantly reduced compared to those in null adenovirus-transduced mice (5% and 35%, vs 20% and 50%, respectively). Meanwhile, subsequent neointimal hyperplasia was obviously increased in IFI35 adenovirus-transduced mice. In vitro studies further indicated that IFI35 inhibits both EC proliferation and migration by inhibiting the NF-κB/p65 pathway. Subsequent studies demonstrated that IFI35 functionally interacted with Nmi through its NID1 domain and that knock-down of Nmi significantly mitigated the inhibitory effect of IFI35 on EC proliferation and migration.

CONCLUSION

Our study revealed a novel mechanism through which IFI35 affects the proliferation and migration of ECs as well as neointima formation, specifically through inhibition of the NF-κB/p65 pathway. Thus, IFI35 is a promising target for the prevention and treatment of post-injury vascular intimal hyperplasia.

Analysis of Combined Transcriptomes Identifies Gene Modules that Differentially Respond to Pathogenic Stimulation of Vascular Smooth Muscle and Endothelial Cells

Smooth muscle cells (SMCs) and endothelial cells (ECs) are vital cell types composing the vascular medial wall and the atheroprotective inner lining, respectively. Current treatments for cardiovascular disease inhibit SMC hyperplasia but compromise EC integrity, predisposing patients to thrombosis. Therapeutics targeting SMCs without collateral damage to ECs are highly desirable. However, differential (SMC versus EC) disease-associated regulations remain poorly defined. We conducted RNA-seq experiments to investigate SMC-versus-EC differential transcriptomic dynamics, following treatment of human primary SMCs and ECs with TNFα or IL-1β, both established inducers of SMC hyperplasia and EC dysfunction. As revealed by combined SMC/EC transcriptomes, after TNFα or IL-1β induction, 174 and 213 genes respectively showed greater up-regulation in SMCs than in ECs (SMC-enriched), while 117 and 138 genes showed greater up-regulation in ECs over SMCs (EC-enriched). Analysis of gene interaction networks identified central genes shared in the two SMC-enriched gene sets, and a distinct group of central genes common in the two EC-enriched gene sets. Significantly, four gene modules (subnetworks) were identified from these central genes, including SMC-enriched JUN and FYN modules and EC-enriched SMAD3 and XPO1 modules. These modules may inform potential intervention targets for selective blockage of SMC hyperplasia without endothelial damage.

Inhibition of p110δ PI3K prevents inflammatory response and restenosis after artery injury

Inflammatory cells play key roles in restenosis upon vascular surgical procedures such as bypass grafts, angioplasty and stent deployment but the molecular mechanisms by which these cells affect restenosis remain unclear. The p110δ isoform of phosphoinositide 3-kinase (PI3K) is mainly expressed in white blood cells. Here, we have investigated whether p110δ PI3K is involved in the pathogenesis of restenosis in a mouse model of carotid injury, which mimics the damage following arterial grafts. We used mice in which p110δ kinase activity has been disabled by a knockin (KI) point mutation in its ATP-binding site (p110δD910A/D910A PI3K mice). Wild-type (WT) and p110δD910A/D910A mice were subjected to longitudinal carotid injury. At 14 and 30 days after carotid injury, mice with inactive p110δ showed strongly decreased infiltration of inflammatory cells (including T lymphocytes and macrophages) and vascular smooth muscle cells (VSMCs), compared with WT mice. Likewise, PI-3065, a p110δ-selective PI3K inhibitor, almost completely prevented restenosis after artery injury. Our data showed that p110δ PI3K plays a main role in promoting neointimal thickening and inflammatory processes during vascular stenosis, with its inhibition providing significant reduction in restenosis following carotid injury. p110δ-selective inhibitors, recently approved for the treatment of human B-cell malignancies, therefore, present a new therapeutic opportunity to prevent the restenosis upon artery injury.

Induced Pluripotent Stem Cell-Derived Endothelial Cells Overexpressing Interleukin-8 Receptors A/B and/or C-C Chemokine Receptors 2/5 Inhibit Vascular Injury Response

Recruitment of neutrophils and monocytes/macrophages to the site of vascular injury is mediated by binding of chemoattractants to interleukin (IL) 8 receptors RA and RB (IL8RA/B) C‐C chemokine receptors (CCR) 2 and 5 expressed on neutrophil and monocyte/macrophage membranes. Endothelial cells (ECs) derived from rat‐induced pluripotent stem cells (RiPS) were transduced with adenovirus containing cDNA of IL8RA/B and/or CCR2/5. We hypothesized that RiPS‐ECs overexpressing IL8RA/B (RiPS‐IL8RA/B‐ECs), CCR2/5 (RiPS‐CCR2/5‐ECs), or both receptors (RiPS‐IL8RA/B+CCR2/5‐ECs) will inhibit inflammatory responses and neointima formation in balloon‐injured rat carotid artery. Twelve‐week‐old male Sprague‐Dawley rats underwent balloon injury of the right carotid artery and intravenous infusion of (a) saline vehicle, (b) control RiPS‐Null‐ECs (ECs transduced with empty virus), (c) RiPS‐IL8RA/B‐ECs, (d) RiPS‐CCR2/5‐ECs, or (e) RiPS‐IL8RA/B+CCR2/5‐ECs. Inflammatory mediator expression and leukocyte infiltration were measured in injured and uninjured arteries at 24 hours postinjury by enzyme‐linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. Neointima formation was assessed at 14 days postinjury. RiPS‐ECs expressing the IL8RA/B or CCR2/5 homing device targeted the injured arteries and decreased injury‐induced inflammatory cytokine expression, neutrophil/macrophage infiltration, and neointima formation. Transfused RiPS‐ECs overexpressing IL8RA/B and/or CCR2/5 prevented inflammatory responses and neointima formation after vascular injury. Targeted delivery of iPS‐ECs with a homing device to inflammatory mediators in injured arteries provides a novel strategy for the treatment of cardiovascular diseases. Stem Cells Translational Medicine2017;6:1168–1177

RhoA determines lineage fate of mesenchymal stem cells by modulating CTGF-VEGF complex in extracellular matrix

Mesenchymal stem cells (MSCs) participate in the repair/remodelling of many tissues, where MSCs commit to different lineages dependent on the cues in the local microenvironment. Here we show that TGFβ-activated RhoA/ROCK signalling functions as a molecular switch regarding the fate of MSCs in arterial repair/remodelling after injury. MSCs differentiate into myofibroblasts when RhoA/ROCK is turned on, endothelial cells when turned off. The former is pathophysiologic resulting in intimal hyperplasia, whereas the latter is physiological leading to endothelial repair. Further analysis revealed that MSC RhoA activation promotes formation of an extracellular matrix (ECM) complex consisting of connective tissue growth factor (CTGF) and vascular endothelial growth factor (VEGF). Inactivation of RhoA/ROCK in MSCs induces matrix metalloproteinase-3-mediated CTGF cleavage, resulting in VEGF release and MSC endothelial differentiation. Our findings uncover a novel mechanism by which cell–ECM interactions determine stem cell lineage specificity and offer additional molecular targets to manipulate MSC-involved tissue repair/regeneration.

It is unclear what regulates the fate of mesenchymal stem cells (MSCs) in arterial repair following injury. Here, the authors show that MSC differentiation following injury is triggered by RhoA which in turn stimulates the release of connective tissue growth factor and vascular endothelial growth factor.

Targeted delivery of human iPS-ECs overexpressing IL-8 receptors inhibits neointimal and inflammatory responses to vascular injury in the rat

Interleukin-8 (IL8) is highly expressed by injured arteries in a variety of diseases and is a chemoattractant for neutrophils which express IL8 receptors IL8RA and RB (IL8RA/B) on their membranes. Neutrophils interact with the damaged endothelium and initiate an inflammatory cascade at the site of injury. We have generated a novel translational targeted cell therapy for acute vascular injury using adenoviral vectors to overexpress IL8RA/B and green fluorescent protein (GFP) on the surface of endothelial cells (ECs) derived from human induced pluripotent stem cells (HiPS-IL8RA/B-ECs). We hypothesize that HiPS-IL8RA/B-ECs transfused intravenously into rats with balloon injury of the carotid artery will target to the injured site and compete with neutrophils, thus inhibiting inflammation and neointima formation. Young adult male Sprague-Dawley rats underwent balloon injury of the right carotid artery and received intravenous transfusion of saline vehicle, 1.5 × 10(6) HiPS-ECs, 1.5 × 10(6) HiPS-Null-ECs, or 1.5 × 10(6) HiPS-IL8RA/B-ECs immediately after endoluminal injury. Tissue distribution of HiPS-IL8RA/B-ECs was analyzed by a novel GFP DNA qPCR method. Cytokine and chemokine expression and leukocyte infiltration were measured in injured and uninjured arteries at 24 h postinjury by ELISA and immunohistochemistry, respectively. Neointimal, medial areas, and reendothelialization were measured 14 days postinjury. HiPS-IL8RA/B-ECs homed to injured arteries, inhibited inflammatory mediator expression and inflammatory cell infiltration, accelerated reendothelialization, and attenuated neointima formation after endoluminal injury while control HiPS-ECs and HiPS-Null-ECs did not. HiPS-IL8RA/B-ECs transfused into rats with endoluminal carotid artery injury target to the injured artery and provide a novel strategy to treat vascular injury.

Brugia malayi Asparaginyl-tRNA Synthetase Stimulates Endothelial Cell Proliferation, Vasodilation and Angiogenesis

A hallmark of chronic infection with lymphatic filarial parasites is the development of lymphatic disease which often results in permanent vasodilation and lymphedema, but all of the mechanisms by which filarial parasites induce pathology are not known. Prior work showed that the asparaginyl-tRNA synthetase (BmAsnRS) of Brugia malayi, an etiological agent of lymphatic filariasis, acts as a physiocrine that binds specifically to interleukin-8 (IL-8) chemokine receptors. Endothelial cells are one of the many cell types that express IL-8 receptors. IL-8 also has been reported previously to induce angiogenesis and vasodilation, however, the effect of BmAsnRS on endothelial cells has not been reported. Therefore, we tested the hypothesis that BmAsnRS might produce physiological changes in endothelial by studying the in vitro effects of BmAsnRS using a human umbilical vein cell line EA.hy926 and six different endothelial cell assays. Our results demonstrated that BmAsnRS produces consistent and statistically significant effects on endothelial cells that are identical to the effects of VEGF, vascular endothelial growth factor. This study supports the idea that new drugs or immunotherapies that counteract the adverse effects of parasite-derived physiocrines may prevent or ameliorate the vascular pathology observed in patients with lymphatic filariasis.

Serum CD121a (Interleukin 1 Receptor, Type I): A Potential Novel Inflammatory Marker for Coronary Heart Disease

Inflammation is now believed to be responsible for coronary heart disease (CHD). This belief has stimulated the evaluation of various inflammatory markers for predicting CHD. This study was designed to investigate the association between four inflammatory cytokines (CD121a, interleukin [IL]-1β, IL-8, and IL-11) and CHD. Here, we evaluated 443 patients with CHD and 160 CHD-free controls who underwent coronary angiography. Cytokines were evaluated using flow cytometry, and statistical analyses were performed to investigate the association between cytokine levels and the risk of CHD. Patients with CHD had significantly higher levels of CD121a. The odds ratios for CHD according to increasing CD121a quartiles were 1.00, 1.47 [95% confidence interval (CI): 0.79–2.72], 2.67 (95% CI: 1.47–4.84), and 4.71 (95% CI: 2.65–8.37) in an age- and sex-adjusted model, compared to 1.00, 1.48 (95% CI: 0.70–3.14), 2.25 (95% CI: 1.10–4.62), and 4.39 (95% CI: 2.19–8.79) in a model that was adjusted for multiple covariates. A comparison of the stable angina, unstable angina, and acute myocardial infarction (AMI) subgroups revealed that patients with AMI had the highest CD121a levels, although IL-1β levels were similar across all groups. IL-8 levels were also increased in AMI patients, and IL-11 levels were higher in CHD patients than in non-CHD patients. Correlation analysis revealed a positive association between CD121a, IL-8, and the Gensini score. Together, the significant increase in CD121a levels among CHD patients suggests that it may be a novel inflammatory marker for predicting CHD.

Hydroxysafflor yellow A inhibits lipopolysaccharide-induced proliferation and migration of vascular smooth muscle cells via Toll-like receptor-4 pathway

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) is closely associated with early vascular hyperplasic lesions. Toll-like receptor (TLR)-4 is a pathogen pattern recognition receptor expressed on VSMCs, and can be activated by lipopolysaccharide. Activated TLR-4 plays a promoting role in VSMCs proliferation and migration through the downstream signaling pathways including Rac1/Akt. Hydroxysafflor yellow A (HSYA) is the main component of the safflower yellow pigments, which has long been used for the treatment of cardiovascular diseases in traditional Chinese medicine. However, the effect of HSYA on VSMC proliferation and migration remains unknown. In the present study, we showed that HYSA could inhibit LPS-induced VSMCs proliferation and migration, accompanied by the downregulated levels of several key pro-inflammatory cytokines, including TNF-α, IL-6, and IL-8. We further showed that HYSA inhibited LPS-induced upregulation of TLR-4 expression as well as the activation of Rac1/Akt pathway, suggesting that HSYA inhibits LPS-induced VSMCs proliferation and migration, partly at least, via inhibition of TLR-4/Rac1/Akt pathway. Accordingly, HSYA may be used as a promising agent for prevention and treatment of vascular hyperplasic disorders.

Targeted delivery of pulmonary arterial endothelial cells overexpressing interleukin-8 receptors attenuates monocrotaline-induced pulmonary vascular remodeling

OBJECTIVE

Interleukin-8 (IL-8) receptors IL8RA and IL8RB (IL8RA/B) on neutrophil membranes bind to IL-8 with high affinity and play a critical role in neutrophil recruitment to sites of injury and inflammation. This study tested the hypothesis that administration of rat pulmonary arterial endothelial cells (ECs) overexpressing IL8RA/B can accelerate the adhesion of ECs to the injured lung and inhibit monocrotaline-induced pulmonary inflammation, arterial thickening and hypertension, and right ventricular hypertrophy.

APPROACH AND RESULTS

The treatment groups included 10-week-old ovariectomized Sprague-Dawley rats that received subcutaneous injection of PBS (vehicle), a single injection of monocrotaline (monocrotaline alone, 60 mg/kg, SC), monocrotaline followed by intravenous transfusion of ECs transduced with the empty adenoviral vector (null-EC), and monocrotaline followed by intravenous transfusion of ECs overexpressing IL8RA/B (1.5 × 10(6) cells/rat). Two days or 4 weeks after monocrotaline treatment, endothelial nitric oxide synthase, inducible nitric oxide synthase, cytokine-induced neutrophil chemoattractant-2β (IL-8 equivalent in rat), and monocyte chemoattractant protein-1 expression, neutrophil and macrophage infiltration into pulmonary arterioles, and arteriolar and alveolar morphology were measured by histological and immunohistochemical techniques. Proinflammatory cytokine/chemokine protein levels were measured by Multiplex rat-specific magnetic bead-based sandwich immunoassay in total lung homogenates. Transfusion of ECs overexpressing IL8RA/B significantly reduced monocrotaline-induced neutrophil infiltration and proinflammatory mediator (IL-8, monocyte chemoattractant protein-1, inducible nitric oxide synthase, cytokine-induced neutrophil chemoattractant, and macrophage inflammatory protein-2) expression in lungs and pulmonary arterioles and alveoli, pulmonary arterial pressure, and pulmonary arterial and right ventricular hypertrophy and remodeling.

CONCLUSIONS

These provocative findings suggest that targeted delivery of ECs overexpressing IL8RA/B is effective in repairing the injured pulmonary vasculature.

The effect of bone marrow mononuclear stem cell therapy on left ventricular function and myocardial perfusion

BACKGROUND

Bone marrow stem cell (BMC) transfer is an emerging therapy with potential to salvage cardiomyocytes during acute myocardial infarction and promote regeneration and endogenous repair of damaged myocardium in patients with left ventricular (LV) dysfunction. We performed a meta-analysis to examine the association between administration of BMC and LV functional recovery as assessed by imaging.

METHODS AND RESULTS

Our meta-analysis included data from 32 trials comprising information on 1,300 patients in the treatment arm and 1,006 patients in the control arm. Overall, BMC therapy was associated with a significant increase in LV ejection fraction by 4.6% ± 0.7% (P < .001) (control-adjusted increase of 2.8% ± 0.9%, P = .001), and a significant decrease in perfusion defect size by 9.5% ± 1.4% (P < .001) (control-adjusted decrease of 3.8% ± 1.2%, P = .002). The effect of BMC therapy was similar whether the cells were administered via intra-coronary or intra-myocardial routes and was not influenced by baseline ejection fraction or perfusion defect size.

CONCLUSIONS

BMC transfer appears to have a positive impact on LV recovery in patients with acute coronary syndrome and those with stable coronary disease with or without heart failure. Most studies were small and a minority used a core laboratory for image analysis.

Pathophysiological role of neutrophils in acute myocardial infarction

The pathogenesis of acute myocardial infarction is known to be mediated by systemic, intraplaque and myocardial inflammatory processes. Among different immune cell subsets, compelling evidence now indicates a pivotal role for neutrophils in acute coronary syndromes. Neutrophils infiltrate coronary plaques and the infarcted myocardium and mediate tissue damage by releasing matrix-degrading enzymes and reactive oxygen species. In addition, neutrophils are also involved in post-infarction adverse cardiac remodelling and neointima formation after angioplasty. The promising results obtained in preclinical modelswith pharmacological approaches interfering with neutrophil recruitment or function have confirmed the pathophysiological relevance of these immune cells in acute coronary syndromes and prompted further studies of these therapeutic interventions. This narrative review will provide an update on the role of neutrophils in acute myocardial infarction and on the pharmacological means that were devised to prevent neutrophil-mediated tissue damage and to reduce post-ischaemic outcomes.

Endothelial cell transfusion ameliorates endothelial dysfunction in 5/6 nephrectomized rats

Endothelial dysfunction is prevalent in chronic kidney disease. This study tested the hypothesis that transfusion of rat aortic endothelial cells (ECs) ameliorates endothelial dysfunction in a rat model of chronic kidney disease. Male Sprague-Dawley rats underwent sham surgery or 5/6 nephrectomy (Nx). Five weeks after Nx, EC (1.5 × 10(6) cells/rat) or vehicle were transfused intravenously. One week later, vascular reactivity of mesenteric artery was assessed on a wire myograph. Sensitivity of endothelium-dependent relaxation to acetylcholine and maximum vasodilation were impaired by Nx and improved by EC transfusion. Using selective pharmacological nitric oxide synthase isoform inhibitors, we demonstrated that the negative effect of Nx on endothelial function and rescue by EC transfusion are, at least in part, endothelial nitric oxide synthase mediated. Plasma asymmetric dimethylarginine was increased by Nx and decreased by EC transfusion, whereas mRNA expression of dimethylarginine dimethylaminohydrolases 1 (DDAH1) was decreased by Nx and restored by EC transfusion. Immunohistochemical staining confirmed that local expression of DDAH1 is decreased by Nx and increased by EC transfusion. In conclusion, EC transfusion attenuates Nx-induced endothelium-dependent vascular dysfunction by regulating DDAH1 expression and enhancing endothelial nitric oxide synthase activity. These results suggest that EC-based therapy could provide a novel therapeutic strategy to improve vascular function in chronic kidney disease.

Endothelial cells overexpressing IL-8 receptor reduce cardiac remodeling and dysfunction following myocardial infarction

The endothelium is a dynamic component of the cardiovascular system that plays an important role in health and disease. This study tested the hypothesis that targeted delivery of endothelial cells (ECs) overexpressing neutrophil membrane IL-8 receptors IL8RA and IL8RB reduces acute myocardial infarction (MI)-induced left ventricular (LV) remodeling and dysfunction and increases neovascularization in the area at risk surrounding the infarcted tissue. MI was created by ligating the left anterior descending coronary artery in 12-wk-old male Sprague-Dawley rats. Four groups of rats were studied: group 1: sham-operated rats without MI or EC transfusion; group 2: MI rats with intravenous vehicle; group 3: MI rats with transfused ECs transduced with empty adenoviral vector (Null-EC); and group 4: MI rats with transfused ECs overexpressing IL8RA/RB (1.5 × 10⁶ cells post-MI). Two weeks after MI, LV function was assessed by echocardiography; infarct size was assessed by triphenyltetrazolium chloride (live tissue) and picrosirus red (collagen) staining, and capillary density and neutrophil infiltration in the area at risk were measured by CD31 and MPO immunohistochemical staining, respectively. When compared with the MI + vehicle and MI-Null-EC groups, transfusion of IL8RA/RB-ECs decreased neutrophil infiltration and pro-inflammatory cytokine expression and increased capillary density in the area at risk, decreased infarct size, and reduced MI-induced LV dysfunction. These findings provide proof of principle that targeted delivery of ECs is effective in repairing injured cardiac tissue. Targeted delivery of ECs to infarcted hearts provides a potential novel strategy for the treatment of acute MI in humans.