Basal Inflammation Research Articles

A30 INHIBITION OF NF-KB SIGNALING IN DCLK1+ CELLS PROMOTES COLONIC INFLAMMATION AND COLITIS-ASSOCIATED CANCER

Abstract Background Colorectal cancer (CRC) is the 2nd leading cause of cancer death in Canada. A major risk factor for this disease is chronic inflammation. Despite the clear link between inflammation and cancer, the exact mechanism by which colitis leads to cancer is unknown. Our group has previously shown that a rare cell type in the gut marked by the expression of doublecortin-like kinase-1 (Dclk1) and known as a tuft cell, is quiescent, long-lived, and resistant to proliferation even upon mutation of the tumor suppressor APC. Interestingly, in the setting of colitis, these APC-mutated tuft cells become powerful cancer-initiating cells, but the mechanism by which this occurs is not known. NF-kB signaling is a major inflammatory pathway active in colitis and that has been linked to colorectal cancer. Inhibition of the NF-kB pathway in intestinal epithelial cells has also been shown to inhibit tumor initiation in a mouse model of colitis-associated cancer (Greten et al., 2004). Aims In the present study, we aim to examine the effect of NF-kB inhibition in tuft cells on colitis-associated cancer. Methods Dclk1CreERT2/APCf/f mice were crossed to IKK-β f/f mice and administered tamoxifen to conditionally knockout the function of both APC and IKK-β in tuft cells. Mice were then exposed to the colitis-inducing agent dextran sodium sulfate (DSS) to induce tumorigenesis. Approximately 16 weeks post-tamoxifen, colonic tumor number and size were analyzed to determine the effect of NF-kB pathway inhibition on tumor initiation and growth, respectively. Extent of inflammation was assessed by myeloperoxidase (MPO) activity and histological damage, and colonic tissue was collected for measurement of inflammatory mediators by qRT-PCR at both acute and long-term time points. Results Interestingly, at baseline we detected increased MPO activity in Dclk1CreERT2/APCf/f/IKK-β f/f mice compared to control mice, suggesting that inhibition of NF-kB in Dclk1+ cells may increase basal colonic inflammation. Consistent with this observation, inhibition of the NF-kB pathway also resulted in an increased number of tuft cell-derived tumors, with no observed change in tumor size. Acutely, we also observed an exacerbation of DSS-colitis in Dclk1CreERT2/APCf/f/IKK-β f/f mice, as detected by elevated MPO activity, increased histological damage, and reduced colon length compared to wildtype (IKK-β +/+) controls. Conclusions These data suggest that Dclk1+ cell-specific NF-kB signaling plays a key protective role against colitis and colitis-associated tumorigenesis. Targeting the NF-kB pathway may reduce the severity of colitis and the incidence of colitis-associated cancer. Funding Agencies CIHR

Structural and ultrastructural renal lesions in rats fed high-fat and high-phosphorus diets.

BackgroundFoods prone to deteriorate renal function are rich in fat and in phosphorus (P), but the interaction between these two factors is not well studied.MethodDetailed structural and ultrastructural histopathological studies were performed on the kidneys of rats fed different amounts of fat and P: low (4%) fat (LF) and normal (0.6%) P (NP), LF and high (1.2%) P (HP), high (35%) fat (HF) and NP, HF and HP, and HF with low (0.2%) P (LP) for 28 weeks.ResultsGlomeruli of the HF groups showed segmental areas of retraction, sclerosis and thickening of the Bowman’s capsule and basal membranes, which were more accentuated in the HF–HP group. Ultrastructural lesions in the glomeruli also were prominent in rats fed HF, particularly in the HF–HP group, and included thickening of the capillary membrane, endothelial damage, mesangial matrix hypercellularity and podocyte effacement. P restriction reduced the severity of endothelial damage, mesangial matrix hypercellularity, thickening of capillary basement membrane and podocyte effacement. The kidneys of rats fed HP showed significant tubular atrophy and dilatation, focal tubular hyperplasia, thickening of the tubular basal membrane, interstitial edema, inflammation and calcification. All groups fed HF also showed tubular lesions that were more prominent in the HF–HP group. P restriction had a beneficial effect on inflammation and calcification.ConclusionsIntake of both HF and HP damages the kidneys and their noxious effects are additive. HF intake was preferentially associated with glomerular lesions, while lesions related to HP intake were located mainly in the tubuli and in the interstitium.

HIV antiretroviral drugs, dolutegravir, maraviroc and ritonavir-boosted atazanavir use different pathways to affect inflammation, senescence and insulin sensitivity in human coronary endothelial cells.

ObjectivesAging HIV-infected antiretroviral-treatment (ART)-controlled patients often present cardiovascular and metabolic comorbidities. Thus, it is mandatory that life-long used ART has no cardiometabolic toxicity. Protease inhibitors have been associated with cardiometabolic risk, integrase-strand-transfer-inhibitors (INSTI) with weight gain and the CCR5 inhibitor maraviroc with improved vascular function. We have previously reported that the INSTI dolutegravir and maraviroc improved, and ritonavir-boosted atazanavir(atazanavir/r) worsened, inflammation and senescence in human coronary artery endothelial cells (HCAEC)s from adult controls. Here, we analyzed the pathways involved in the drugs’ effects on inflammation, senescence and also insulin resistance.MethodsWe analyzed the involvement of the anti-inflammatory SIRT-1 pathway in HCAECs. Then, we performed a transcriptomic analysis of the effect of dolutegravir, maraviroc and atazanavir/r and used siRNA-silencing to address ubiquitin-specific-peptidase-18 (USP18) involvement into ART effects.ResultsDolutegravir reduced inflammation by decreasing NFκB activation and IL-6/IL-8/sICAM-1/sVCAM-1 secretion, as did maraviroc with a milder effect. However, when SIRT-1 was inhibited by splitomicin, the drugs anti-inflammatory effects were maintained, indicating that they were SIRT-1-independant.From the transcriptomic analysis we selected USP18, previously shown to decrease inflammation and insulin-resistance. USP18-silencing enhanced basal inflammation and senescence. Maraviroc still inhibited NFκB activation, cytokine/adhesion molecules secretion and senescence but the effects of dolutegravir and atazanavir/r were lost, suggesting that they involved USP18. Otherwise, in HCAECs, dolutegravir improved and atazanavir/r worsened insulin resistance while maraviroc had no effect. In USP18-silenced cells, basal insulin resistance was increased, but dolutegravir and atazanavir/r kept their effect on insulin sensitivity, indicating that USP18 was dispensable.ConclusionUSP18 reduced basal inflammation, senescence and insulin resistance in coronary endothelial cells. Dolutegravir and atazanavir/r, but not maraviroc, exerted opposite effects on inflammation and senescence that involved USP18. Otherwise, dolutegravir improved and atazanavir/r worsened insulin resistance independently of USP18. Thus, in endothelial cells, dolutegravir and atazanavir/r oppositely affected pathways leading to inflammation, senescence and insulin resistance.

Identification of predictors of cerebrovascular infarcts in patients with tuberculous meningitis.

Tuberculous meningitis (TBM) remains common in developing countries. Cerebrovascular infarct (CI) in TBM occurs in 15%-57% of patients. Literature regarding the predictors of central nervous system (CNS) infarct in patients with TBM is scanty, and the outcome of these events is unknown. The aim of this study is to evaluate the predictors of CI among patients with TBM at a tertiary care center in South India and to compare the impact of CI on the prognosis and outcomes in terms of mortality and morbidity. All patients who were confirmed to have TBM and CNS infarcts/stroke were included in this study retrospectively. Forty-six patients had appropriate imaging, and they were enrolled in the study as cases. Patients without infarct were matched with age and sex as controls. Details of the course of the disease, the extent of CNS involvement, and treatment were compared between the two arms. The mean age of patients with and without infarct was similar. The presence of basal meningeal inflammation, hydrocephalus, focal neurological deficit, and cranial nerve palsy, was higher in patients with infarct. Independent predictors of infarcts in a patient with TBM were Medical Research Council (MRC) staging of II or more, presence of focal neurological deficit, cranial nerve palsy, and presence of hydrocephalus, meningeal enhancement on neuroimaging. Presences of infarcts were independently associated with a higher odds ratio of 2.58 for poor outcome, 4.48 for a longer duration of hospital stay, and odds ratio of 8.85 for the requirement of multiple hospitalizations. CI involvement in TBM has higher morbidity, with longer stay, recurrent admission.

Macrophage Immunometabolism and Inflammaging: Roles of Mitochondrial Dysfunction, Cellular Senescence, CD38, and NAD.

Aging is a complex process that involves dysfunction on multiple levels, all of which seem to converge on inflammation. Macrophages are intimately involved in initiating and resolving inflammation, and their dysregulation with age is a primary contributor to inflammaging—a state of chronic, low-grade inflammation that develops during aging. Among the age-related changes that occur to macrophages are a heightened state of basal inflammation and diminished or hyperactive inflammatory responses, which seem to be driven by metabolic-dependent epigenetic changes. In this review article we provide a brief overview of mitochondrial functions and age-related changes that occur to macrophages, with an emphasis on how the inflammaging environment, senescence, and NAD decline can affect their metabolism, promote dysregulation, and contribute to inflammaging and age-related pathologies.

Histological Markers of Clinical Relapse in Endoscopically Quiescent Ulcerative Colitis.

In ulcerative colitis (UC) patients who have achieved mucosal healing, active microscopic colonic mucosal inflammation is commonly observed. We aimed to assess the association between histological activity and disease relapse in endoscopically quiescent UC. Ulcerative colitis patients with endoscopically quiescent disease and ≥12 months of follow-up were included. Biopsies were reviewed for the presence of basal plasmacytosis (BPC) and active histological inflammation, defined as a Geboes score (GS) ≥3.2. Primary outcome measures were disease relapse at 18 months and time to first relapse after index colonoscopy. Seventy-six UC patients (51% male; mean age, 38.6 years; median follow-up [range], 75.2 [2-118] months) were included. Sixty-two percent had an endoscopic Mayo score of 0 at index colonoscopy. Basal plasmacytosis was present in 46% and active histological inflammation in 30% of subjects. Presence of BPC was associated with a significantly shorter time to disease relapse (P = 0.01). Active histological inflammation was significantly associated with clinical relapse at 18 months (P = 0.0005) and shorter time to clinical relapse (P = 0.0006). Multivariate analysis demonstrated active histological inflammation to be independently associated with clinical relapse at 18 months and time to clinical relapse. In endoscopically quiescent UC, active histological inflammation and the presence of BPC are adjunctive histological markers associated with increased likelihood of disease relapse. Although prospective studies are required, the presence of these histological markers should be a factor considered when making therapeutic decisions in UC.

Intense Physical Exercise Induces an Anti-inflammatory Change in IgG N-Glycosylation Profile.

Exercise is known to improve many aspects of human health, including modulation of the immune system and inflammatory status. It is generally understood that exercise reduces inflammation, but there are missing links in terms of understanding the mechanisms as well as the differences between exercise modalities. N-glycosylation of immunoglobulin G (IgG) and total plasma proteins was previously shown to reflect changes in inflammatory pathways, which could provide valuable information to further clarify exercise effects. In order to further expand the understanding of the relationship between physical activity and inflammation, we examined the effect of intense exercise, in the form of repeated sprint training (RST), on IgG and total plasma proteins N-glycosylation in combination with traditionally used inflammation markers: C-reactive protein (CRP), interleukin 6 (IL-6), and leukocyte count. Twenty-nine male physical education students were separated into treatment (RST, N = 15) and control (N = 14) groups. The RST group completed a 6-week exercise protocol while the control group was instructed to refrain from organized physical activity for the duration of the study. Three blood samples were taken at different time points: prior to start of the training program, the final week of the exercise intervention (EXC), and at the end of the 4-week recovery period (REC). Following the end of the recovery period IgG N-glycosylation profiles showed anti-inflammatory changes in RST group compared to the control group, which manifested as a decrease in agalactosylated (p = 0.0473) and an increase in digalactosylated (p = 0.0473), and monosialylated (p = 0.0339) N-glycans. Plasma protein N-glycans didn’t change significantly, while traditional inflammatory markers also didn’t show significant change in inflammatory status. Observed results demonstrate the potential of intense physical exercise to reduce levels of systemic basal inflammation as well as the potential for IgG N-glycosylation to serve as a sensitive longitudinal systemic inflammation marker.

Effects of aging and lifelong aerobic exercise on basal and exercise-induced inflammation.

Age-associated chronic basal inflammation compromises muscle mass and adaptability, but exercise training may exert an anti-inflammatory effect. This investigation assessed basal and exercise-induced inflammation in three cohorts of men: young exercisers [YE; n = 10 men; 25 ± 1 yr; maximal oxygen consumption (V̇o2max), 53 ± 3 mL·kg-1·min-1; quadriceps area, 78 ± 3 cm2; means ± SE], old healthy nonexercisers (OH; n = 10; 75 ± 1 yr; V̇o2max, 22 ± 1 mL·kg-1·min-1; quadriceps area, 56 ± 3 cm2), and lifelong exercisers with an aerobic training history of 53 ± 1 yr (LLE; n = 21; 74 ± 1 yr; V̇o2max, 34 ± 1 mL·kg-1·min-1; quadriceps area, 67 ± 2 cm2). Resting serum IL-6, TNF-α, C-reactive protein, and IGF-1 levels were measured. Vastus lateralis muscle biopsies were obtained at rest (basal) and 4 h after an acute exercise challenge (3 × 10 repetitions, 70% 1-repetition maximum) to assess gene expression of cytokines [IL-6, TNF-α, IL-1β, IL-10, IL-4, interleukin-1 receptor antagonist (IL-1Ra), and transforming growth factor-β (TGF-β)], chemokines [IL-8 and monocyte chemoattractant protein-1 (MCP-1)], cyclooxygenase enzymes [cyclooxygenase-1 and -2 (COX-1 and COX-2, respectively), prostaglandin E2 synthases [microsomal prostaglandin E synthase 1 (mPGES-1) and cytosolic prostaglandin E2 synthase (cPGES)] and receptors [prostaglandin E2 receptor EP3 and EP4 subtypes (EP3 and EP4, respectively), and macrophage markers [cluster of differentiation 16b (CD16b) and CD163], as well as basal macrophage abundance (CD68+ cells). Aging led to higher (P ≤ 0.05) circulating IL-6 and skeletal muscle COX-1, mPGES-1, and CD163 expression. However, LLE had significantly lower serum IL-6 levels (P ≤ 0.05 vs. OH) and a predominantly anti-inflammatory muscle profile [higher IL-10 (P ≤ 0.05 vs. YE), TNF-α, TGF-β, and EP4 levels (P ≤ 0.05 vs. OH)]. In OH only, acute exercise increased expression of proinflammatory factors TNF-α, TGF-β, and IL-8 (P ≤ 0.05). LLE had postexercise gene expression similar to YE, except lower IL-10 (P ≤ 0.10), mPGES-1, and EP3 expression (P ≤ 0.05). Thus, although aging led to a proinflammatory profile within blood and muscle, lifelong exercise partially prevented this and generally preserved the acute inflammatory response to exercise seen in young exercising men. Lifelong exercise may positively impact muscle health throughout aging by promoting anti-inflammation in skeletal muscle.NEW & NOTEWORTHY This study assessed a unique population of lifelong aerobic exercising men and demonstrated that their activity status exerts an anti-inflammatory effect in skeletal muscle and circulation. Furthermore, we provide evidence that the inflammatory response to acute exercise is dysregulated by aging but preserved with lifelong exercise, which might improve skeletal muscle resilience to unaccustomed loading and adaptability into late life.

Defined neuronal populations drive fatal phenotype in a mouse model of Leigh syndrome.

Mitochondrial deficits in energy production cause untreatable and fatal pathologies known as mitochondrial disease (MD). Central nervous system affectation is critical in Leigh Syndrome (LS), a common MD presentation, leading to motor and respiratory deficits, seizures and premature death. However, only specific neuronal populations are affected. Furthermore, their molecular identity and their contribution to the disease remains unknown. Here, using a mouse model of LS lacking the mitochondrial complex I subunit Ndufs4, we dissect the critical role of genetically-defined neuronal populations in LS progression. Ndufs4 inactivation in Vglut2-expressing glutamatergic neurons leads to decreased neuronal firing, brainstem inflammation, motor and respiratory deficits, and early death. In contrast, Ndufs4 deletion in GABAergic neurons causes basal ganglia inflammation without motor or respiratory involvement, but accompanied by hypothermia and severe epileptic seizures preceding death. These results provide novel insight in the cell type-specific contribution to the pathology, dissecting the underlying cellular mechanisms of MD.

The association between insomnia, c-reactive protein, and chronic low back pain: cross-sectional analysis of the HUNT study, Norway.

Chronic low back pain (chronic LBP) is the number one cause for years lived with disability among 301 diseases and injuries analyzed by The Global Burden of Disease study 2013. Insomnia is highly prevalent among people with chronic LBP. To explain the sleep-pain relationship, theoretical models propose that insomnia symptoms may be associated with increased basal inflammation, operationalized as c-reactive protein (CRP) and lead to further pain and disrupted sleep. We aimed to determine the associations between insomnia, chronic LBP, and inflammation (operationalized as CRP), whilst controlling for age, body mass index, smoking, physical activity, depression, anxiety and osteoarthritis. A cross-sectional analysis of the third Nord-Trøndelag Health Study (2006-2008), a rural population survey of 50,666 participants in Norway aged 20-96 years. Insomnia (dichotomous) was defined according to the Diagnostic and Statistical Manual of Mental Disorders 5th Edition, and chronic LBP (dichotomous) as low back pain or stiffness lasting at least 3 months. Data for CRP were obtained from non-fasting serum samples and assessed via latex immunoassay methodology. We excluded participants with the following self-reported chronic somatic diseases: chronic heart failure, chronic obstructive pulmonary disease, rheumatoid arthritis, fibromyalgia or ankylosing spondylosis. Possible associations between presence of insomnia and presence of chronic LBP (dependent), and the level of CRP and presence of chronic LBP (dependent), were assessed using logistic regression models. The possible association between insomnia and CRP (dependent) was assessed using linear regression. Multivariable analyses were conducted adjusting for confounders stated in our aim that achieved p ≤ 0.2 in univariate regressions. We performed stratified analyses for participants with "Normal" (<3 mg/L) "Elevated" (3-10 mg/L) and "Very High" (>10 mg/L) levels of CRP. In our total included sample (n = 30,669, median age 52.6, 54% female), 6.1% had insomnia (n = 1,871), 21.4% had chronic LBP (n = 6,559), and 2.4% had both (n = 719). Twenty four thousand two hundred eighty-eight (79%) participants had "Normal" CRP, 5,275 (17%) had "Elevated" CRP, and 1,136 (4%) had "Very High" CRP. For participants with "Normal" levels of CRP, insomnia was associated with higher levels of CRP (adjusted B = 0.04, 95%CI [0.00-0.08], p = 0.046), but not for people with "Elevated" or "Very High" levels of CRP. There was an association between CRP and presence of chronic LBP in the total sample (adjusted OR = 1.01, [1.00-1.01], p = 0.013) and for people with "Normal" CRP (1.05, [1.00-1.10, p = 0.034]. Insomnia was associated with the presence of chronic LBP in the total sample (adjusted OR = 1.99, 95%CI [1.79-2.21], <0.001) and for people with "Normal", "Elevated" and "Very High". Individuals with insomnia have twice the odds of reporting chronic LBP. Insomnia, CRP and chronic LBP appear to be linked but the role of CRP appears to be limited. Longitudinal studies may help further explore the causal inference between insomnia chronic LBP, and inflammation. Given the strong relationship between insomnia and chronic LBP, screening and management of comorbid insomnia and chronic LBP should be considered in clinical practice. Further longitudinal studies are required to explore whether the presence of insomnia and increased inflammation affects the development of chronic LBP.

Development of lacrimal gland inflammation in the mouse model of herpes stromal keratitis

Herpes stromal keratitis (HSK) is a chronic immunoinflammatory condition which develops in response to recurrent herpes simplex virus-1 (HSV-1) infection of the cornea. Patients with HSK often demonstrate the concurrence of corneal desiccation and the loss of blink reflex. However, the relationship between severity of HSK, level of basal tears and inflammation of the lacrimal gland is mostly unexplored. In this study, we compared these variables in extraorbital lacrimal gland (EoLG) after corneal HSV-1 infection in the C57BL/6J mouse model. Our results showed a significant reduction in the volume of tears in infected eyes during the development of HSK. Extensive architectural damage to EoLG, presumably caused by a massive influx of interferon-gamma secreting T cells, was observed during clinical disease period of HSK. A positive correlation between the decrease in tear volume, severity of HSK and the damage to EoLG were evident in infected mice. The presence of infectious virus measured in EoLG during pre-clinical, but not clinical disease period of HSK, suggested that viral cytopathic effects are not the major contributors of extensive damage seen in EoLG. Furthermore, topical administration of lacritin peptide delayed but did not prevent the decrease in tears in HSV-1 infected mice, and had no significant effect in either reducing the severity of HSK or T cell infiltration in EoLG of infected mice. Together, our results showed an interplay between the severity of HSK, inflammation of EoLG, and the reduced level of tears after corneal HSV-1 infection.

Sphingosine kinase 1-interacting protein is a dual regulator of insulin and incretin secretion.

Our previous study demonstrated that sphingosine kinase 1-interacting protein (SKIP, or Sphkap) is expressed in pancreatic β-cells, and depletion of SKIP enhances glucose-stimulated insulin secretion. We find here that SKIP is also expressed in intestinal K- and L-cells and that secretion of gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) as well as insulin are significantly increased, and blood glucose levels are decreased in SKIP-deficient (SKIP-/-) mice compared with those in wild-type mice. Plasma triglyceride (Tg), LDL cholesterol, and mRNA levels of proinflammatory cytokines in adipose tissues, livers, and intestines were found to be significantly decreased in SKIP-/- mice. The phenotypic characteristics of SKIP-/- mice, including adiposity and attenuation of basal inflammation, were abolished by genetic depletion of GIP. The improvement of glucose tolerance and lipid profiles in SKIP-/- mice were cancelled by GLP-1 receptor antagonist exendin-(9-39) treatment. In summary, depletion of SKIP ameliorates glucose tolerance by enhancing secretion of insulin and incretins, improves lipid metabolism, and reduces basal inflammation levels. Thus, inhibition of SKIP action may emerge as a new option for treatment of type 2 diabetes mellitus with metabolic dysfunction.-Liu, Y., Harashima, S., Wang, Y., Suzuki, K., Tokumoto, S., Usui, R., Tatsuoka, H., Tanaka, D., Yabe, D., Harada, N., Hayashi, Y., Inagaki, N. Sphingosine kinase 1-interacting protein is a dual regulator of insulin and incretin secretion.

Decreased Erythrocyte Binding Capability for Neutrophil Siglec-9 Is a Source of Oxidative Stress in Sickle Cell Disease

IntroductionOxidative stress and inflammation promote hemolysis and vaso-occlusion in sickle cell disease (SCD). Erythrocytes can play a pro-oxidative and anti-oxidative role in disease-associated inflammation through iron-driven free radical production and endogenous anti-oxidants. In SCD, HbS accelerated auto-oxidation, iron de-compartmentalization, and inflammatory cell-derived oxidants drive this oxidative stress. CD33-related Sialic acid-binding immunoglobulin-type lectins (CD33rSiglecs) are cell surface proteins that recognize sialic acids in “Self-Associated Molecular Patterns” (SAMPs) and typically inhibit innate immune cell functions via cytosolic signaling. Recent studies have shown that Siglec-9 on human neutrophils in circulating blood interact with erythrocyte sialic acids (prominently glycophorin-A (GYPA) to suppress neutrophil reactivity, including reactive oxygen species (ROS) production. Modification of erythrocyte membrane sialic acids interferes with their ability to inhibit neutrophil activation and oxidative burst. As erythrocytes age and undergo cellular damage there is a loss of membrane bound sialoglycoproteins. Several studies have indicated that this reduction in the sialome is accelerated on the sickle erythrocyte. We hypothesize that altered sickle erythrocyte membrane sialic acid leads to decreased Siglec-9 binding capability, and that decreased binding of neutrophil Siglec-9 to sickle erythrocyte sialic acid enhances neutrophil activation and oxidative burst.Methods & ResultsBinding of recombinant Siglec-9-Fc protein to AA (n=9) and SS erythrocytes (n=7) was measured using flow cytometry. SS erythrocytes displayed significantly less Siglec-9-Fc binding 45% ± 11.9 (mean ± SEM) compared to AA erythrocytes 82% ± 5.4 (p=.03). Treatment of AA erythrocytes with neuraminidase to remove sialic acid decreased binding to 4% ± 7.9.Neutrophil ROS production was measured by flow cytometry using dihydrorhodamine 123 (DHR123). Neutrophils were purified from AA donors (n=5) and SS (n=11) or AA erythrocytes (n=5) were added to the neutrophils at a ratio of 50 erythrocytes to 1 neutrophil. Oxidative burst was stimulated using phorbol 12-myristate 13-acetate (PMA). AA erythrocytes decreased PMA-stimulated neutrophil ROS production by 84% ± 6.7. In contrast, SS erythrocytes decreased PMA-stimulated neutrophil ROS production by 53% ± 6.8 (p=0.03,).Recent studies have shown that neutrophil extracellular trap (NET) formation is pathogenic in SCD. We added AA and SS erythrocytes (50:1) to neutrophils stimulated with PMA and NET formation was assessed using Syto Orange, Syto Green and confocal microscopy. PMA-stimulated neutrophils incubated with AA erythrocytes showed minimal NET formation. In contrast, AA erythrocytes treated with neuraminidase to remove sialic acid had increased NET formation. PMA-stimulated neutrophils incubated with SS erythrocytes showed increased NET formation.ConclusionsA constant disease state of oxidative stress and inflammation underlies SCD pathophysiology. These data demonstrate that SS erythrocytes with decreased membrane sialic acid are deficient in binding to neutrophil Siglec-9. The decreased binding of SS erythrocytes to neutrophil Siglec-9 diminishes the ability of SS erythrocytes to properly modulate neutrophil activation, which may contribute to the oxidative stress and increased state of basal inflammation inherent to SCD. The overall reduction in number of RBCs in SS may also be a factor? [Display omitted] DisclosuresBelcher:CSL Behring: Research Funding. Vercellotti:CSL Behring: Research Funding.

Association between baseline pro-inflammatory cytokines and brain activation during social exclusion in patients with vulnerability to suicide and depressive disorder

BackgroundNeuroimaging studies suggest that social distress and suicidal vulnerability share common cerebral bases. Moreover, increased peripheral inflammatory activity is involved in both social distress and suicidal behavior. ObjectiveTo evaluate, in suicidal and non-suicidal individuals, the association between the activation of specific cerebral regions (anterior cingulate, insula and orbitofrontal cortex) during experimental social exclusion and the baseline blood levels of the pro-inflammatory cytokines interleukin-6 (IL-6), interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) and of the anti-inflammatory cytokine interleukin-2 (IL-2). MethodsIn total, 101 euthymic women were recruited: 42 suicide attempters (SA), 40 affective controls (AC), and 19 healthy controls (HC). During functional MRI (fMRI), they performed the Cyberball game, a validated social exclusion task. Blood levels of IL-1β, IL-6, TNF-α and IL-2 were measured prior to fMRI. The activation of insula, orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC) during the explicit social exclusion (ESE) vs social inclusion (INC) conditions of the Cyberball game was analyzed in function of the baseline cytokine levels. ResultsIL-1β was negatively associated with right OFC activation (p = 0.01) in ESE vs. INC, whereas IL-2 was positively associated with activation of the right ACC (p = 0.02), insula (p = 0.002) and OFC (p = 0.004) in ESE vs. INC. These associations remained significant after controlling for group, indicating that they were independent of the suicidal status. ConclusionBaseline IL-1β and IL-2 blood levels are differentially associated with cerebral activation involved in the perception of social exclusion, independently of suicidal behavior. Our results may help to better understand the role of basal inflammation in social distress and its link with mood disorder pathophysiology.

Chronic Family Stress and Adolescent Health: The Moderating Role of Emotion Regulation.

The aim of the study was to assess whether the association between chronic family stress and physiological measures is moderated by emotion regulation strategies in an adolescent sample. Chronic family stress was assessed via a semistructured interview and emotion regulation strategies (cognitive reappraisal and suppression) via questionnaire among 261 adolescents (14.57 (1.07) years). Several metabolic (waist-hip ratio, systolic and diastolic blood pressure) and inflammatory markers (basal and stimulated proinflammatory cytokine production in response to bacterial challenge) as well as glucocorticoid sensitivity were assessed. There were no main effects of chronic family stress, cognitive reappraisal, or suppression on physiological measures (all p's > .10). Emotion regulation moderated the association between chronic family stress and physiological measures. As chronic family stress increased, adolescents higher in cognitive reappraisal had smaller waist-hip ratios (B = -.003, SE = .001, p = .015) and lower systolic blood pressure (B = -.303, SE = .143, p = .035), although no moderation was found with respect to inflammatory markers and glucocorticoid sensitivity (all p's > .30). In addition, as chronic family stress increased, adolescents higher in suppression showed evidence of higher stimulated proinflammatory cytokine production (B = .046, SE = .020, p = .021) and lower glucocorticoid sensitivity (B = .051, SE = .021, p = .015), although basal inflammation and metabolic measures were not moderated by suppression (all p's > .50). This study suggests that the types of emotion regulation strategies used by adolescents may affect the extent to which chronic family stress affects important metabolic and immune processes.

Behavioral immune system activity predicts downregulation of chronic basal inflammation.

Here, we present a mechanistically grounded theory detailing a novel function of the behavioral immune system (BIS), the psychological system that prompts pathogen avoidance behaviors. We propose that BIS activity allows the body to downregulate basal inflammation, preventing resultant oxidative damage to DNA and promoting longevity. Study 1 investigated the relationship between a trait measure of pathogen avoidance motivation and in vitro and in vivo proinflammatory cytokine production. Study 2 examined the relationship between this same predictor and DNA damage often associated with prolonged inflammation. Results revealed that greater trait pathogen avoidance motivation predicts a) lower levels of spontaneous (but not stimulated) proinflammatory cytokine release by peripheral blood mononuclear cells (PBMCs), b) lower plasma levels of the proinflammatory cytokine interleukin-6 (IL-6), and c) lower levels of oxidative DNA damage. Thus, the BIS may promote health by protecting the body from the deleterious effects of inflammation and oxidative stress.

Proinflammatory Cytokine and Adipokine Levels in Adult Unrelated Marrow Donors Are Not Associated with Hematopoietic Cell Transplantation Outcomes

Graft-versus-host disease (GVHD) is a frequent cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HCT). GVHD occurs when donor lymphocytes are activated by inflammatory cytokines and alloantigens. The role of donor biologic characteristics, such as basal inflammation, has not been investigated as a risk factor for GVHD but is theoretically transferrable to the recipient. We evaluated donor serum and plasma concentrations of cytokines and adipokines (IL-1β, IL-6, tumor necrosis factor [TNF]-α, leptin, suppression of tumorigenicity-2, and adiponectin) from test (n = 210) and replication (n = 250) cohorts of matched, unrelated transplant peripheral blood stem cell recipients identified through the Center for International Blood and Marrow Transplantation Research between 2000 and 2011 for hematologic malignancies. Hazard ratios were estimated for acute (grades II to IV and III to IV) and chronic GVHD, overall survival, disease-free survival, transplant-related mortality, and relapse for each cytokine or adipokine, adjusting for significant covariates. The lowest cytokine quartile was considered as the reference group for each model. To account for multiple testing P < .01 was considered the threshold for significance. In the test cohort a borderline significant association was identified between donor serum IL-1β concentrations and grades III to IV acute GVHD in the recipient (P = .01), and a significant inverse association was identified between donor TNF-α concentrations and chronic GVHD (P = .006). These findings were not validated in the replication cohort. Although the initial associations between cytokine levels and allo-HCT outcomes were not validated, the idea that donor characteristics may be transferable to the recipient remains an exciting area for future research.

Modulation of epigenetic bet proteins with RVX-208 in inflammatory monocytes from diabetic subjects

Aim: Bromodomain and extraterminal (BET) proteins are important mediators of inflammation through epigenetic remodelling. Diabetic patients have an increased risk of developing atherosclerosis and present basal inflammation in monocytes. The RVX-208 compound is an epigenetic BET inhibitor with anti-inflammatory properties, shown with in vivo and in vitro studies. We aimed to determine whether using RVX-208 can have ex vivo anti-inflammatory properties on monocytes from diabetic patients, challenged with lipopolysaccharide (LPS).

The prognostic factors of HIV-negative adult cryptococcal meningitis with a focus on cranial MRI-based neuroimaging findings

The prognostic significance of clinical characteristics and neuroimaging features, especially cranial magnetic resonance imaging (MRI)-based neuroimaging features, in patients with human immunodeficiency virus (HIV)-negative cryptococcal meningitis (CM) has rarely been examined in the literature. We analyzed the clinical characteristics and MRI findings of 65 HIV-negative patients (43 men, 22 women, age 19–86 years) collected during a study period of 15 years (January 2001–December 2015). Their underlying conditions included diabetes mellitus, liver cirrhosis, hematologic disorders, autoimmune disorders, malignancy, chronic obstructive pulmonary disease, adrenal insufficiency and organ transplantation, and their clinical presentations included headache, altered consciousness, fever, seizure, visual disturbance and hearing impairment. The main cranial MRI findings were basal meningeal enhancement (44.6%, 29/65), dilated Virchow-Robin space/pseudocyst (43.1%, 28/65), “dirty” cerebrospinal fluid sign (38.5%, 25/65), hydrocephalus (36.9%, 21/65), acute/subacute cerebral infarct (ASCI, 21.5%, 14/65), cryptococcoma (9.2%, 6/65), and hazy brain base (1.5%, 1/65). The therapeutic results of the 65 patients were evaluated using the Glasgow Outcome Scale (GOS). A comparison of the good outcome group (GOS score = 4–5, n = 37) and poor outcome group (GOS score = 1–3, n = 28) revealed that both the presence of seizures and ASCI were significantly associated with the prognosis. A comparison of the groups with ASCI (n = 14) and without ASCI (n = 51) revealed that the presence of basal meningeal enhancement was a significant factor for the development of ASCI, and that this correlation may be associated with intense basal meningeal inflammation in adjacent small vessels.

Arachidonic acid supplementation transiently augments the acute inflammatory response to resistance exercise in trained men.

Strenuous exercise can result in skeletal muscle damage, leading to the systemic mobilization, activation, and intramuscular accumulation of blood leukocytes. Eicosanoid metabolites of arachidonic acid (ARA) are potent inflammatory mediators, but whether changes in dietary ARA intake influence exercise-induced inflammation is not known. This study investigated the effect of 4 wk of dietary supplementation with 1.5 g/day ARA ( n = 9, 24 ± 1.5 yr) or corn-soy oil placebo ( n = 10, 26 ± 1.3 yr) on systemic and intramuscular inflammatory responses to an acute bout of resistance exercise (8 sets each of leg press and extension at 80% one-repetition maximum) in previously trained men. Whole EDTA blood, serum, peripheral blood mononuclear cells (PMBCs), and skeletal muscle biopsies were collected before exercise, immediately postexercise, and at 2, 4, and 48 h of recovery. ARA supplementation resulted in higher exercise-stimulated serum creatine kinase activity [incremental area under the curve (iAUC) P = 0.046] and blood leukocyte counts (iAUC for total white cells, P < 0.001; neutrophils: P = 0.007; monocytes: P = 0.015). The exercise-induced fold change in peripheral blood mononuclear cell mRNA expression of interleukin-1β ( IL1B), CD11b ( ITGAM), and neutrophil elastase ( ELANE), as well as muscle mRNA expression of the chemokines interleukin-8 ( CXCL8) and monocyte chemoattractant protein 1 ( CCL2) was also greater in the ARA group than placebo. Despite this, ARA supplementation did not influence the histological presence of leukocytes within muscle, perceived muscle soreness, or the extent and duration of muscle force loss. These data show that ARA supplementation transiently increased the inflammatory response to acute resistance exercise but did not impair recovery. NEW & NOTEWORTHY Daily arachidonic acid supplementation for 4 wk in trained men augmented the acute systemic and intramuscular inflammatory response to a subsequent bout of resistance exercise. Greater exercise-induced inflammatory responses in men receiving arachidonic acid supplementation were not accompanied by increased symptoms of exercise-induced muscle damage. Although increased dietary arachidonic acid intake does not appear to influence basal inflammation in humans, the acute inflammatory response to exercise stress is transiently increased following arachidonic acid supplementation.