Augmented Inflammation Research Articles

Fibrin lysability is associated with central obesity and inflammation in women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is characterized by increased central fat mass (CFM), hyper-inflammation, and hemostatic alterations; the risk of cardiovascular disease may also be increased. Reduced fibrin lysability is a risk factor for cardiovascular disease. The present study assessed fibrin lysability in women with PCOS and controls of similar age and body mass index. Ninety women with PCOS and 35 controls of comparable age and body mass index were included. Hemostatic markers (fibrin lysability, fibrinogen, coagulation factor XIII, plasminogen, plasminogen activator inhibitor 1 [PAI-1], plasmin inhibitor, thrombin activatable fibrinolysis inhibitor (TAFI), D-dimer), C-reactive protein (CRP), body mass index, waist-to-hip ratio, CFM determined by Dual-energy X-ray absorptiometry scan, and sex hormones (testosterone estradiol, and sex hormone binding globulin) were determined. TAFI and CRP were higher in women with PCOS, than controls. In women with PCOS, fibrin lysability correlated with CFM, waist-to-hip ratio, CRP, fibrinogen, and all hemostatic variables (P≤.004) except TAFI and D-dimer. CFM correlated with fibrinogen, CRP, coagulation factor XIII, waist-to-hip ratio, plasminogen, PAI-1, plasmin inhibitor, and TAFI (P<.02). In controls, fibrin lysability correlated with CFM, fibrinogen, coagulation factor XIII, and plasmin inhibitor (P≤.02). CFM correlated with PAI-1, plasmin inhibitor, coagulation factor XIII, fibrinogen, and CRP (P≤.05). Stepwise regression analysis revealed that fibrin lysability was associated with CFM, fibrinogen and CRP in women with PCOS (r2 =.46, P≤.001), but only with CFM in controls (r2 =.28, P<.001). Fibrin lysability was comparable in women with PCOS and controls. Fibrin lysability was associated with CFM and hyper-inflammation in women with PCOS, but only with CFM in controls. These findings suggest that obese women with PCOS and augmented inflammation could have an increased risk of cardiovascular disease.

Soluble Uric Acid Promotes Atherosclerosis via AMPK (AMP-Activated Protein Kinase)-Mediated Inflammation

Uric acid is supposed but not yet determined to be associated with atherosclerosis. Uric acid is released from damaged cells to form urate crystal, which is recognized by the immune system to produce IL (interleukin)-1. Danger signals and IL-1 have been shown to play an important role in atherosclerosis. We determined whether the physiological level of soluble uric acid promotes inflammation and develops atherosclerosis. Approach and Results: The secretion of IL-1β from human peripheral blood mononuclear cells mediated by NLRP3 (NACHT, LRR, and PYD domain-containing protein 3) inflammasome was promoted by physiological levels in serum uric acid. This augmentation of inflammation was mediated by the regulation of the AMPK (AMP-activated protein kinase)-mTOR (mammalian target of rapamycin) mitochondrial reactive oxygen species and HIF-1α (hypoxia-inducible factor-1α) pathway. In both of uricase transgenic and xanthine oxidase inhibitor-treated mice, decreased levels of uric acid resulted in the activation of AMPK and attenuation of the development of atherosclerotic plaques. Further, acute uric acid reduction by the administration of benzbromarone in healthy humans for 2 weeks significantly decreased plasma IL-18-an inflammasome-dependent cytokine. The data indicate that the development of atherosclerosis and inflammation is promoted by uric acid in vivo. Moreover, the lowering of uric acid levels attenuated inflammation via the activation of the AMPK pathway. This study provides mechanistic evidence of uric acid-lowering therapies for atherosclerosis.

The impact of rehabilitation frequency on the risk of stroke in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis are at higher risk of developing stroke due to augmented systemic inflammation. While regular exercise has been shown to reduce inflammation in human subjects, the purpose of our study is to determine whether increased frequency of rehabilitation is protective against stroke or not. A total of 16,224 rheumatoid arthritis patients with a catastrophic illness certificate were identified in our database from 2000 to 2006, and 663 of them developed stroke before the end of 2013. After statistically matching for age, sex, and the time interval between the diagnosis of rheumatoid arthritis and stroke, 642 patients without stroke were identified as the control group. Analyses with Student's t test and Chi-square test were done to compare the clinical characteristics of patients with and without stroke, and logistic regression analysis was then performed to evaluate the odds ratio of stroke. Higher odds ratio of stroke was revealed in patients with hypertension, diabetes mellitus, and moderate degree of rheumatoid arthritis disease severity. Furthermore, more than 40 rehabilitation sessions per year reduced the risk of developing stroke in patients with moderate disease severity. Physical activities brought by more rehabilitation sessions are beneficial and should be encouraged in patients with rheumatoid arthritis, particularly for those with higher disease activity but not taking biologic agents.

Refractory neutrophil activation in type 2 diabetics with chronic periodontitis.

Inflammation increases diabetes mellitus type 2 (T2DM) progression and severity. T2DM patients are at high risk of the rapid development of chronic periodontitis (CP). Topical presence, high numbers, and bactericidal effects of immune cells are challenged by augmented antigen-induced inflammation, which promotes both diseases. To investigate gingival cellular inflammatory responses in individuals with previously undiagnosed T2DM with CP or CP alone and in systemically and periodontally healthy controls (H) in vivo and to establish an ex vivo technique permitting quantitative and qualitative assessments of gingival crevicular immune cells. T2DM+CP, CP, and H individuals (n=10, each) received a 2-week oral hygiene regimen (OHR). Afterwards, a noninvasive sampling technique was performed to evaluate gingival inflammation induced under standardized conditions in vivo, that is, in the absence of severe periodontal destruction and inflammation at clinically healthy sites. Stimuli (casein/test or phosphate-buffered saline w/o. Ca2+ or Mg2+ , PBS(-/-) /control) were randomly applied contralaterally in the gingival sulci of participants' upper dentes canini. One day after completion of the OHR, gingival crevicular fluid (GCF) was kinetically assayed between the time of the baseline (BL) measurement and 55minutes. Polymorphonuclear leukocyte (PMN) content (PMNGCF ) was quantitated at an optimum time of 35minutes. PMNGCF counts reflect local inflammation. Ex vivo samples were fluorimetrically labeled, gated according to the donor's peripheral blood polymorphonuclear neutrophils (PMNPB ), and then counted, employing flow cytometry. PMNGCF counts in unstimulated gingival crevices (at BL) in the T2DM+CP group were higher than those in the CP and H groups. PMNGCF counts were elevated in casein vs PBS(-/-) -stimulated gingival crevices in all groups. Patients with T2DM+CP showed increased PMNGCF counts compared to those with CP (P=.035) according to scatter plots. CD45+ counts in the stimulated sites in T2DM+CP patients were higher than those in CP and H patients (P=.041). Under stimulation conditions, the CD45+ counts differed from those under placebo conditions (P=.019), indicating augmented, inducible inflammatory leukocyte infiltrate in T2DM+CP patients. This noninvasive technique permits quantitative assessment of (experimental) gingival inflammation in vivo, revealing an influence of T2DM+CP on the number of primary immune cells in the gingival crevice. Patients who are challenged with (local) leukocytosis are likely at risk of collateral damage to the gingival crevice neighboring tissues, favoring the severity and progression of CP and consequently T2DM (www.clinicaltrials.gov NCT01848379).

P1937Deficiency of PI 3-kinase isoform p110alpha in smooth muscle cells impairs vascular integrity and promotes aortic aneurysm formation

Abstract Background The pathobiology of aortic aneurysms is characterized by vascular inflammation, extracellular matrix degeneration, and particularly by loss and dedifferentiation of vascular smooth muscle cells (SMCs). In SMCs, the PI 3-kinase isoform p110α mediates receptor tyrosine kinase dependent proliferation, chemotaxis, and survival. Smooth muscle specific p110α deficient mice (SM-p110α−/− mice) display reduced medial wall thickness, substantially reduced neointima formation and media hypertrophy after balloon injury of the carotid artery. Objective We hypothesized that loss of p110α signaling impairs vascular integrity and promotes development and progression of abdominal aortic aneurysms (AAA). We aimed to elucidate the impact of p110α deficiency on vascular integrity, SMC phenotypic modulation, vascular inflammation, and AAA formation. Methods and results Ultra-structural characterization of aortic wall morphology in abdominal aortas from SM-p110α−/− mice by transmission electron microscopy (TEM) revealed disarranged structure of tunica media as indicated by disorganized elastic fibers, detached SMCs, and elastic fiber breaks. Western blots showed reduced elastin and fibrillin expression in SMCs from p110α−/− mice. Media thickness was significantly reduced in abdominal aortas from SM-p110α−/− mice compared to wild type (WT) controls (29.0±3.1 vs. 42.5±4.1 μm). Lack of p110α decreased expression of differentiation markers SM-α-actin and SM-MHC. p110α deficiency significantly diminished responsiveness of aortic rings to vasodilator acetylcholine. These data indicate loss of differentiation and impaired contractility of p110α−/− SMCs. We subjected SM-p110α−/− mice and WT littermate controls to the porcine pancreatic elastase (PPE) model of AAA. PPE was infused into the infrarenal aorta, respectively, to induce AAA formation. Ultrasonic examination of abdominal aortas demonstrated an enlarged aortic diameter in PPE challenged mice. AAA formation was significantly (p&lt;0.01) enhanced in SM-p110α−/− (0.46±0.12 mm, n=8) compared to SM-p110α+/+ mice (0.18±0.03 mm, n=4). These data indicate a protective function of p110α in AAA formation. Immunocytochemistry of the aortic medial compartment from PPE-perfused SM-p110α−/− mice revealed significantly increased MOMA-2+ monocyte/macrophage content indicating augmented aortic inflammation during AAA formation compared to WT controls. Furthermore, SMCs from SM-p110α−/− mice expressed reduced amounts of anti-inflammatory angiopoietin1 compared to p110α+/+ SMCs. Moreover, frequent apoptotic/necrotic SMCs were found in the aortic media of SM-p110α−/− mice by TEM, potentially contributing to vascular inflammation in a critical fashion. Conclusion These data indicate that p110α signaling critically contributes to vascular integrity via maintaining SMC plasticity, elastic fiber homeostasis, and anti-inflammatory processes. Consequently, lack of proper p110α signaling promotes progression of AAA formation.

Angiotensin II type 2 receptor and angiotensin-converting enzyme 2 mediate ischemic renal injury in diabetic and non-diabetic rats

AimDepressor arm of the renin-angiotensin system (RAS) exerts reno-protective effects in chronic kidney diseases like diabetic nephropathy. However, same is still elusive under AKI and hyperglycaemia comorbidity. Hence, the present study delineates the role of angiotensin-II type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2) in AKI under normal and hyperglycaemia condition. MethodsNon-diabetic (ND) and Streptozotocin-induced diabetes mellitus (DM) rats were subjected to ischemic renal injury (IRI). Rats underwent IRI were treated with an AT2R agonist, C21 (0.3 mg/kg/day, i.p.) or ACE2 activator, Dize, (5 mg/kg/day, p.o.) either alone or as combination therapy. Renal histopathology and immunohistochemistry, proximal tubular fraction isolation, ELISA, immunoblotting and qRT-PCR were performed for subsequent analysis. Key findingsRats subjected to IRI displayed an increase in plasma ACE, AT1R, AT2R, Ang II, and reduction in ACE2, Ang-(1–7) expressions, with augmented renal inflammation and apoptosis. These changes were more prominent in diabetic rats with IRI. Co-administration of C21 and Dize augmented ACE2, Ang-(1–7), AT2R and MasR expressions, and attenuated tubular injury in both DM and ND rats. ConclusionWe demonstrated that pharmacological activation of AT2R and ACE2 protects DM and ND rats from IRI by preventing oxidative stress, inflammation and apoptosis-mediated tubular damage.

An interaction between MKL1, BRG1, and C/EBPβ mediates palmitate induced CRP transcription in hepatocytes

Non-alcoholic steatohepatitis (NASH) is one of the most predominant disorders in metabolic syndrome. Induction of pro-inflammatory mediators in hepatocytes exposed to free fatty acids represents a hallmark event during NASH pathogenesis. C-reactive protein (CRP) is a prototypical pro-inflammatory mediator. In the present study, we investigated the mechanism by which megakaryocytic leukemia 1 (MKL1) mediates palmitate (PA) induced CRP transcription in hepatocytes. We report that over-expression of MKL1, but not MKL2, activated the CRP promoter whereas depletion or inhibition of MKL1 repressed the CRP promoter. MKL1 potentiated the induction of the CRP promoter activity by PA treatment. Importantly, MKL1 knockdown by siRNA or pharmaceutical inhibition by CCG-1423 attenuated the induction of endogenous CRP expression in hepatocytes. Similarly, primary hepatocytes isolated from wild type (WT) mice produced more CRP than those isolated from MKL1 deficient (KO) mice when stimulated with PA. Mechanistically, the sequence-specific transcription factor CCAAT-enhancer-binding protein (C/EBPβ) interacted with MKL1 and recruited MKL1 to activate CRP transcription. Reciprocally, MKL1 modulated C/EBPβ activity by recruiting the chromatin remodeling protein BRG1 to the CRP promoter to alter histone modifications. In conclusion, our data delineate a novel epigenetic mechanism underlying augmented hepatic inflammation during NASH pathogenesis.

Exosomes containing HIV protein Nef reorganize lipid rafts potentiating inflammatory response in bystander cells.

HIV infection has a profound effect on “bystander” cells causing metabolic co-morbidities. This may be mediated by exosomes secreted by HIV-infected cells and containing viral factors. Here we show that exosomes containing HIV-1 protein Nef (exNef) are rapidly taken up by macrophages releasing Nef into the cell interior. This caused down-regulation of ABCA1, reduction of cholesterol efflux and sharp elevation of the abundance of lipid rafts through reduced activation of small GTPase Cdc42 and decreased actin polymerization. Changes in rafts led to re-localization of TLR4 and TREM-1 to rafts, phosphorylation of ERK1/2, activation of NLRP3 inflammasome, and increased secretion of pro-inflammatory cytokines. The effects of exNef on lipid rafts and on inflammation were reversed by overexpression of a constitutively active mutant of Cdc42. Similar effects were observed in macrophages treated with exosomes produced by HIV-infected cells or isolated from plasma of HIV-infected subjects, but not with exosomes from cells and subjects infected with ΔNef-HIV or uninfected subjects. Mice injected with exNef exhibited monocytosis, reduced ABCA1 in macrophages, increased raft abundance in monocytes and augmented inflammation. Thus, Nef-containing exosomes potentiated pro-inflammatory response by inducing changes in cholesterol metabolism and reorganizing lipid rafts. These mechanisms may contribute to HIV-associated metabolic co-morbidities.

Acetylcholine-producing T cells augment innate immune-driven colitis but are redundant in T cell-driven colitis.

Clinical trials suggest that vagus nerve stimulation presents an alternative approach to classical immune suppression in Crohn's disease. T cells capable of producing acetylcholine (ChAT+ T cells) in the spleen are essential mediators of the anti-inflammatory effect of vagus nerve stimulation. Besides the spleen, ChAT+ T cells are found abundantly in Peyer's patches of the small intestine. However, the role of ChAT+ T cells in colitis pathogenesis is unknown. Here, we made use of CD4creChATfl/fl mice (CD4ChAT-/- mice) lacking ChAT expression specifically in CD4+ T cells. Littermates (ChATfl/fl mice) served as controls. In acute dextran sulfate sodium (DSS)-induced colitis (7 days of 2% DSS in drinking water), CD4ChAT-/- mice showed attenuated colitis and lower intestinal inflammatory cytokine levels compared with ChATfl/fl mice. In contrast, in a resolution model of DSS-induced colitis (5 days of 2% DSS followed by 7 days without DSS), CD4ChAT-/- mice demonstrated a worsened colitis recovery and augmented colonic histological inflammation scores and inflammatory cytokine levels as compared with ChATfl/fl mice. In a transfer colitis model using CD4+CD45RBhigh T cells, T cells from CD4ChAT-/- mice induced a similar level of colitis compared with ChATfl/fl T cells. Together, our results indicate that ChAT+ T cells aggravate the acute innate immune response upon mucosal barrier disruption in an acute DSS-induced colitis model, whereas they are supporting the later resolution process of this innate immune-driven colitis. Surprisingly, ChAT expression in T cells seems redundant in the context of T cell-driven colitis.NEW & NOTEWORTHY By using different mouse models of experimental colitis, we provide evidence that in dextran sulfate sodium-induced colitis, ChAT+ T cells capable of producing acetylcholine worsen the acute immune response, whereas they support the later healing phase of this innate immune-driven colitis.

SAT-211 SERUM ADIPOCYTE FATTY ACID BINDING PROTEIN LEVEL IS POSITIVELY ASSOCIATED WITH AORTIC ARTERIAL STIFFNESS IN CHRONIC KIDNEY DISEASE PATIENTS

The adipocyte-fatty-acid-binding protein (A-FABP) plays a crucial role in development of insulin resistance and atherosclerosis by the interaction of metabolic and inflammatory pathways in adipocytes and macrophages. Chronic kidney disease (CKD) accelerates atherosclerosis via augmentation of inflammation, perturbation of lipid metabolism, and other mechanisms. The aim of this study was to evaluate the relationship between serum A-FABP levels and carotid-femoral pulse wave velocity (cfPWV) values in patients with CKD. Fasting blood samples and baseline characteristics were obtained from 270 patients with CKD (stage 1-5). Serum A-FABP concentrations were determined by enzyme immunoassay kit. High aortic stiffness was defined as carotid-femoral pulse wave velocity (cfPWV) values >10 m/s according to the ESH-ESC 2013 guidelines. Among 270 CKD patients, 92 patients (34.1%) were in the high aortic stiffness group. When compared to those in the low aortic stiffness group, the high aortic stiffness group had high prevalence of diabetes mellitus (P = 0.004), older age (P < 0.001), higher waist circumference (P = 0.004), body fat mass (P = 0.010), systolic blood pressure (P < 0.001), fasting glucose (P = 0.014), blood urea nitrogen (P = 0.009), creatinine (P = 0.004), and higher serum A-FABP level (P < 0.001), while lower estimated glomerular filtration rate (P = 0.001). Multivariable logistic regression analysis of the factors significantly associated with aortic stiffness revealed that A-FABP levels (odds ratio (OR): 1.174, 95% confidence interval (CI): 1.047–1.317, P = 0.006), age (OR: 1.062, 95% CI: 1.033–1.092, P = 0.001), and systolic blood pressure (OR: 1.017, 95% CI: 1.003–1.031, P = 0.015) were the independent predictors of aortic stiffness in CKD patients. Multivariable forward stepwise linear regression analysis also showed that A-FABP level (β = 0.178, P = 0.001) was an independent predictor of cfPWV values in CKD patients. There were significant increases in cfPWV values (P = 0.001) and serum A-FABP levels (P < 0.001) across increasing CKD stages. Elevated A-FABP concentration could be a predictor for aortic stiffness in patients with CKD. Increased CKD stages will elevate in cfPWV values and serum A-FABP levels.

Myeloid-Related Protein 8/14 Participates in the Progression of Experimental Pneumococcal Meningitis by Augmentation of Inflammation.

It has been reported that myeloid-related protein 8/14 (MRP8/14) participates in the progression of inflammation after release from neutrophils and monocytes. This study aimed to clarify the mechanism(s) of the MRP8/14-augmented inflammatory response in mice with pneumococcal meningitis. Streptococcus pneumoniae (SP) meningitis was established by intracerebral injection of SP suspension. Balb/c mice were randomly divided into four groups and received the following injections: phosphate-buffer saline (PBS), MRP8/14 alone, SP alone, and SP plus MRP8/14. At 6h, 24h and 48h postinfection, the clinical disease status was measured by the modified neurological severity score test, body weight loss and degree of cerebral edema; mice were anaesthetized, blood samples and brain samples were collected and brain inflammation was detected by haematoxylin and eosin (HE) staining; tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP) and monocyte chemoattractant protein-1 (MCP-1) levels in serum and brain homogenates were assessed by an enzyme-linked immunosorbent assay (ELISA), and the mRNA levels of the above cytokines in brain homogenates were measured by polymerase chain reaction (PCR); and the expression of nuclear factor-kappa B (NF-κB) p65 in brain tissues was determined by immunohistochemical assay. In this study, we identified that MRP8/14 substantially augmented the SP-stimulated inflammatory response, aggravated clinical disease status and exacerbated SP-induced brain edema in a murine model of pneumococcal meningitis. Exogenous administration of MRP8/14 significantly enhanced mRNA and protein expression of the proinflammatory cytokines and chemokines TNF-α, CRP, IL-6 and MCP-1 in brain homogenates and serum from mice with pneumococcal meningitis, which may be related to the NF-κB signalling pathway. We further found that MRP8/14 strongly augmented SP-induced phosphorylation of NF-κB p65 in brain tissue slices from the same model. In conclusion, our results indicated that MRP8/14 augmented the inflammatory response in mice with pneumococcal meningitis and contributed to the development of disease, which was probably through NF-κB signalling pathway activation.

MAP kinase phosphatase (Mkp)-1 Controls Program Death-Ligand (PD-L)1 Expression during Sepsis

Abstract Mkp-1 is a critical negative regulator of the inflammatory response, and plays a crucial role for bacterial clearance in an animal model of sepsis. Mkp-1−/− mice exhibit augmented inflammation, increased bacterial burden, elevated organ damage, and increase mortality relative to Mkp-1+/+ mice following E. coli infection. To understand the functions of Mkp-1, we performed RNA-seq with mouse livers. Under normal conditions, 357 genes were differentially expressed between Mkp-1+/+ and Mkp-1−/− mice. However, following E. coli infection &amp;gt; 5,400 genes displayed differential expression between the two groups. Among genes upregulated by E. coli infection and exacerbated by Mkp-1−/− are PD-L1 and CTLA-4, two key immune checkpoint proteins. Interestingly, the expression of PD-L1 and CTLA-4 were highly correlated with the expression of IL-6, IL-10, and STAT3. qRT-PCR and Western blot analyses verified E. coli infection-induced PD-L1 expression and further exacerbation in Mkp-1−/− mice. Examination of the RNA-seq dataset revealed a clear interferon signature. ELISA analyses on the serum revealed low IFN-β levels in uninfected Mkp-1+/+ and Mkp-1−/− mice, increased IFN-β levels in E. coli-infected Mkp-1+/+ mice, and further augmented IFN-β levels in E. coli-infected Mkp-1−/− mice. Similarly, Mkp-1−/− bone marrow-derived macrophages also produced more IFN-β following stimulation with either LPS or heat-killed E. coli than Mkp-1+/+ macrophages. Our studies indicate that expression of immune check point proteins, PD-L1 and CTLA-4, are controlled by Mkp-1 during microbial infection. Our studies also suggest that exaggerated expression of type I interferons and PD-L1 contribute to the phenotypes of Mkp-1−/− mice in the model of sepsis.

LAIR-1 Limits Neutrophilic Airway Inflammation.

Neutrophils are crucial to antimicrobial defense, but excessive neutrophilic inflammation induces immune pathology. The mechanisms by which neutrophils are regulated to prevent injury and preserve tissue homeostasis are not completely understood. We recently identified the collagen receptor leukocyte-associated immunoglobulin-like receptor (LAIR)-1 as a functional inhibitory receptor on airway-infiltrated neutrophils in viral bronchiolitis patients. In the current study, we sought to examine the role of LAIR-1 in regulating airway neutrophil responses in vivo. LAIR-1-deficient (Lair1−/−) and wild-type mice were infected with respiratory syncytial virus (RSV) or exposed to cigarette smoke as commonly accepted models of neutrophil-driven lung inflammation. Mice were monitored for cellular airway influx, weight loss, cytokine production, and viral loads. After RSV infection, Lair1−/− mice show enhanced airway inflammation accompanied by increased neutrophil and lymphocyte recruitment to the airways, without effects on viral loads or cytokine production. LAIR-1-Fc administration in wild type mice, which blocks ligand induced LAIR-1 activation, augmented airway inflammation recapitulating the observations in Lair1−/− mice. Likewise, in the smoke-exposure model, LAIR-1 deficiency enhanced neutrophil recruitment to the airways and worsened disease severity. Intranasal CXCL1–mediated neutrophil recruitment to the airways was enhanced in mice lacking LAIR-1, supporting an intrinsic function of LAIR-1 on neutrophils. In conclusion, the immune inhibitory receptor LAIR-1 suppresses neutrophil tissue migration and acts as a negative regulator of neutrophil-driven airway inflammation during lung diseases. Following our recent observations in humans, this study provides crucial in-vivo evidence that LAIR-1 is a promising target for pharmacological intervention in such pathologies.

Sphingosine 1-phosphate and inflammation.

AbstractSphingosine 1-phosphate (S1P), a sphingolipid mediator, regulates various cellular functions via high-affinity G protein-coupled receptors, S1P1-5. The S1P-S1P receptor signaling system plays important roles in lymphocyte trafficking and maintenance of vascular integrity, thus contributing to the regulation of complex inflammatory processes. S1P is enriched in blood and lymph while maintained low in intracellular or interstitial fluids, creating a steep S1P gradient that is utilized to facilitate efficient egress of lymphocytes from lymphoid organs. Blockage of the S1P-S1P receptor signaling system results in a marked decrease in circulating lymphocytes because of a failure of lymphocyte egress from lymphoid organs. This provides a basis of immunomodulatory drugs targeting S1P1 receptor such as FTY720, an immunosuppressive drug approved in 2010 as the first oral treatment for relapsing-remitting multiple sclerosis. The S1P-S1P receptor signaling system also plays important roles in maintenance of vascular integrity since it suppresses sprouting angiogenesis and regulates vascular permeability. Dysfunction of the S1P-S1P receptor signaling system results in various vascular defects, such as exaggerated angiogenesis in developing retina and augmented inflammation due to increased permeability. Endothelial-specific deletion of S1P1 receptor in mice fed high-fat diet leads to increased formation of atherosclerotic lesions. This review highlights the importance of the S1P-S1P receptor signaling system in inflammatory processes. We also describe our recent findings regarding a specific S1P chaperone, apolipoprotein M, that anchors to high-density lipoprotein and contributes to shaping the endothelial-protective and anti-inflammatory properties of high-density lipoprotein.

Progressive Hemodynamic and Cardiac Autonomic Impairment as a Function of Metabolic State: Local Adipose vs. Systemic Inflammation

Cardiac autonomic neuropathy (CAN) commonly occurs early in the course of diabetes with significant cardiovascular mortality and morbidity. CAN development is linked to hyperglycemia; however, current understanding extends cardiovascular risk to pre‐diabetic patients without glycemic changes. Recent evidence suggests that anti‐diabetic drugs reduce the risk of cardiovascular complications in pre‐diabetes. The mechanism leading to early CAN development, its temporal evolution from pre‐diabetes to diabetes, and the response to therapeutic interventions were not previously described. To address these questions, we developed a rat model of mildly increased caloric intake (HC‐rat) with delayed development of hyperglycemia. Twelve weeks of feeding were not associated with an increase in neither body weight, blood pressure, nor blood glucose levels. These rats only showed an elevated serum insulin level indicative of insulin resistance. Type 2 diabetes was induced by the injection of low‐dose streptozotocin (STZ, 40 mg/kg). Echocadiography and invasive hemodynamic recording were used to assess cardiac autonomic function. Western blotting, PCR, and immunohistochemistry were employed to investigate different changes on the structural and molecular levels. Pre‐diabetic rats showed localized perivascular adipose inflammation together with parasympathetic dysfunction (suppression of baroreflex sensitivity in response to vasopressors), with no signs of cardiac structural or functional impairment. These abnormalities were reversed by non‐hypoglycemic doses of Metformin (Met, 100 mg/Kg) and Pioglitazone (Pio, 2.5 mg/Kg). On the other hand, rats with overt hyperglycemia developed systemic inflammation, with increased IL‐1b levels in serum, brainstem, and heart apex. Augmentation of inflammation in diabetic rats was associated with worsening cardiac autonomic function extending to sympathetic function (suppression of baroreflex sensitivity in response to vasodilators). While control of hyperglycemia through insulin treatment reversed the sympathetic deficit, parasympathetic function was only restored by combined treatment with Insulin+Met or Insulin+Pio producing the highest decrease in systemic inflammation in diabetic rats. As well, diabetic rats showed signs of focal ischemia in ventricular tissues together with an impaired systolic function apparent as &gt;50% decrease in maximal rate of rise of left ventricular pressure. Our present results outline a framework for sequential involvement of disparate detrimental mechanisms in the course of metabolic disease leading to a differential impact on cardiac autonomic control. Furthermore, our findings emphasize the value of early intervention with antidiabetic drugs with potential pleotropic effects.Support or Funding InformationSupported by AUB‐FM MPP grant # 320148This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The effects of lycopene on alloxan induced diabetic optic neuropathy

Aim To determine the effects of lycopene treatment in prevention of diabetes associated inflammatory response and oxidative stress in an experimental model. With this aim we investigated the levels of oxidative stress markers including Malondialdehyde (MDA), and total oxidative status (TOS)together with inflammatory markers including nuclear factor- kappa B (NFKB) and tumor necrosis factor α (TNF-α) and antioxidants including total glutathione (TGSH), total oxidative status (TOS) and total anti-oxidative status (TAS) levels on eye tissue. Material and methods Totally 18 albino Wistar male rats (250–280 grams) assigned into three groups, with six rats in each group as follows: healthy group (HG), control group (CG), and lycopene group (LG). The diabetes was induced with alloxan administration in rats of CG and LG. Lycopene (4 mg/kg) was administered to the rats in LG once a day for 3 months. At the end of this period, the animals were sacrificed and their eyes were enucleated for histopathological evaluations. From the tissues, MDA, GSH, TOS, TAS, TNF-α and NF-κB levels were analyzed. Results MDA, TOS, OSI, NFKB and TNF-α levels were significantly higher, while TGSH and TAS levels were significantly lower in CG compared with HG (p < 0.001). On the other hand in LG; MDA, TOS, OSI, NFKB and TNF-α levels were significantly lower, while TGSH and TAS levels were significantly higher compared with CG (p < 0.001). Regarding histopathological findings, although there was severe damage on optic nerve of rats in CG; there was only a slight damage in lycopene administered group. Conclusion For the first time in literature we determined that, lycopene was significantly effective in prevention of augmented inflammation and oxidative stress on eye tissue associated with diabetes, as well as the tissue damage on optic nerve. However, studies investigating the long-term clinical effects of lycopene on diabetic individuals are warranted.

Roles of mitochondrial ROS and NLRP3 inflammasome in multiple ozone-induced lung inflammation and emphysema

BackgroundMitochondrial damage leading to oxidant stress may play an important role in the pathogenesis of airflow obstruction and emphysema. NLPR3 inflammasome can be activated by mitochondrial ROS (mtROS) and other stimuli. We examined the importance of mtROS and NLRP3 inflammasome and their interactions in multiple ozone-induced lung inflammation and emphysema.MethodsC57/BL6 mice were exposed to ozone (2.5 ppm, 3 h) or filtered air twice a week over 6 weeks. MitoTEMPO (20 mg/kg), an inhibitor of mtROS, and VX765 (100 mg/kg), an inhibitor of caspase-1 activity, were administered by intraperitoneal or intragastric injection respectively 1 h prior to each ozone exposure for 6 weeks.ResultsOzone-exposed mice had increased bronchoalveolar lavage (BAL) total cells and levels of IL-1β, KC and IL-6, augmented lung tissue inflammation scores, enhanced oxidative stress with higher serum 8-OHdG concentrations, emphysema with greater mean linear intercept (Lm), airway remodeling with increased airway smooth muscle mass and airflow limitation as indicated by a reduction in the ratio of forced expiratory volume at 25 and 50 milliseconds to forced vital capacity (FEV25/FVC, FEV50/FVC). Both MitoTEMPO and VX765 reduced lung inflammation scores, cytokine levels, oxidative stress and increased mitochondrial fission proteins. VX765 also attenuated emphysema, airway remodeling and airflow limitation. MitoTEMPO inhibited the increased expression of mitochondrial complex II and IV and of NLPR3 while VX765 inhibited the expression and activity of NLRP3 and caspase-1 pathway in the lung.ConclusionsBoth mtROS and NLRP3 inflammasome play a role in ozone-induced lung inflammation while only NLRP3 is involved in ozone-induced emphysema.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Blood Electrolytes and Metabolites-A Randomized Controlled Trial.

Cardiac surgery with cardiopulmonary bypass (CPB) causes an acute lung ischemia-reperfusion injury, which can develop to pulmonary dysfunction postoperatively. This sub-study of the Pulmonary Protection Trial aimed to elucidate changes in arterial blood gas analyses, inflammatory protein interleukin-6, and metabolites of 90 chronic obstructive pulmonary disease patients following two lung protective regimens of pulmonary artery perfusion with either hypothermic histidine-tryptophan-ketoglutarate (HTK) solution or normothermic oxygenated blood during CPB, compared to the standard CPB with no pulmonary perfusion. Blood was collected at six time points before, during, and up to 20 h post-CPB. Blood gas analysis, enzyme-linked immunosorbent assay, and nuclear magnetic resonance spectroscopy were used, and multivariate and univariate statistical analyses were performed. All patients had decreased gas exchange, augmented inflammation, and metabolite alteration during and after CPB. While no difference was observed between patients receiving oxygenated blood and standard CPB, patients receiving HTK solution had an excess of metabolites involved in energy production and detoxification of reactive oxygen species. Also, patients receiving HTK suffered a transient isotonic hyponatremia that resolved within 20 h post-CPB. Additional studies are needed to further elucidate how to diminish lung ischemia-reperfusion injury during CPB, and thereby, reduce the risk of developing severe postoperative pulmonary dysfunction.

A Novel Brain Injury Biomarker Correlates with Cyanosis in Infants with Congenital Heart Disease.

Cyanotic heart lesions are a complex subset of congenital heart disease (CHD) in which patients are desaturated until surgical repair or palliation. We hypothesized that a direct relationship would exist between degree of desaturation and presence of systemic inflammation and brain injury in unrepaired patients less than 1year of age. The pre-operative desaturation with augmented systemic inflammation would predict a more complex post-operative course. Fifty patients with CHD were enrolled in this study and classified as cyanotic (O2 ≤ 90%) or acyanotic (O2 > 90%) based on SpO2. Serum inflammatory mediators measured included interleukins (IL)-6, IL-8, IL-12p70, IL-10, IL-1β, tumor necrosis factor (TNF)-α, interferon (INF)-γ; macrophage inhibitory factor (MIF) and a novel brain biomarker, phosphorylated neurofilament heavy subunit (pNF-H). Twenty-two cyanotic and 28 acyanotic subjects were enrolled with SpO2 of 78 ± 18% and 98 ± 2% (p < 0.001), respectively, and mean age of 72days (range 2-303) and 102days (range 1-274), respectively. Cyanotic vs acyanotic subjects had elevated serum IL-6 (6.6 ± 7.6 vs 2.9 ± 2.9pg/ml, p = 0.019) and pNF-H (222 ± 637 vs 57 ± 121pg/ml, p = 0.046), and both biomarkers correlated with degree of desaturation (Spearman rank-order correlation ρ = - 0.30, p = 0.037 and ρ = - 0.29 p = 0.049, respectively). Post-operative inotrope scores at 24h and duration of mechanical ventilation correlated inversely with pre-operative oxygen saturation (ρ = - 0.380, p = 0.014 and ρ = - 0.362, p = 0.020, respectively). The degree of pre-operative desaturation correlated with a more complicated post-operative course supporting the need for advanced peri-operative therapy in this population.

Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model

In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E2 (PGE2), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE2 synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE2 concentration that was completely abrogated in mPGES-1-deficient mice. PGE2 is known to inhibit TNF-α synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-α expression. Due to the impaired PGE2 production, TNF-α expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-α resulted in an enhanced IL-1β production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE2 production by mPGES-1 ablation enhanced the TNF-α-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.