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Tumors can induce systemic disturbances in distant organs, leading to physiological changes that enhance host morbidity. In Drosophila cancer models, tumors have been known for decades to cause hypervolemic "bloating" of the abdominal cavity. Here we use allograft and transgenic tumors to show that hosts display fluid retention associated with autonomously defective secretory capacity of fly renal tubules, which function analogous to those of the human kidney. Excretion from these organs is blocked by abnormal cells that originate from inappropriate activation of normally quiescent renal stem cells (RSCs). Blockage is initiated by IL-6-like oncokines that perturb renal water-transporting cells and trigger a damage response in RSCs that proceeds pathologically. Thus, a chronic inflammatory state produced by the tumor causes paraneoplastic fluid dysregulation by altering cellular homeostasis of host renal units.

Inflammation appears to be a critical mechanism in the development of alcohol use disorder (AUD) and a consequence of chronic alcohol use. The potential anti-inflammatory properties of cannabis may modulate the proinflammatory effects of alcohol. This study sought to extend previous work investigating the relationship between alcohol consumption, cannabis use and circulating interleukin (IL)-6 levels in a sample with AUD. One hundred and thirty-three individuals with an AUD provided blood samples to assess IL-6 and answered questions regarding alcohol and cannabis use. An ordinary least squares multiple regression analysis was conducted to assess the effect of alcohol and cannabis use on IL-6. A moderation analysis examined cannabis use as a potential moderator of the relationship between alcohol use and circulating IL-6 levels. Alcohol use was predictive of higher log IL-6 levels (standardized β = 0.16, p = 0.03), while cannabis use was not predictive of log IL-6 levels (p = 0.36). Days of cannabis use moderated the relationship between alcohol use and IL-6 levels, such that the relationship between alcohol use and IL-6 levels was only significant in individuals with AUD without recent cannabis use. This study extends previous work to a clinical sample with an AUD and underscores the importance of considering cannabis use in studies on alcohol use and inflammation. This study also indicates the need for in-depth analyses on cannabinoids and inflammation and the interaction between cannabinoids and alcohol use on inflammation.

Acute disseminated encephalomyelitis (ADEM) is one characteristic manifestation of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). A previously healthy man presented with retro-orbital headache and urinary retention 14 days after Tdap vaccination. Brain and spine MRI suggested a CNS demyelinating process. Despite treatment with IV steroids, he deteriorated, manifesting hemiparesis and later impaired consciousness, requiring intubation. A repeat brain MRI demonstrated new bilateral supratentorial lesions associated with venous sinus thrombosis, hemorrhage, and midline shift. Anti-MOG antibody was present at a high titer. CSF IL-6 protein was >2,000 times above the upper limits of normal. He improved after plasma exchange, then began monthly treatment alone with anti-IL-6 receptor antibody, tocilizumab, and has remained stable. This case highlights how adult-onset MOGAD, like childhood ADEM, can rapidly become life-threatening. The markedly elevated CSF IL-6 observed here supports consideration for evaluating CSF cytokines more broadly in patients with acute MOGAD.

The Phenome-Wide Association Study (PheWAS) is increasingly used to broadly screen for potential treatment effects, e.g., IL6R variant as a proxy for IL6R antagonists. This approach offers an opportunity to address the limited power in clinical trials to study differential treatment effects across patient subgroups. However, limited methods exist to efficiently test for differences across subgroups in the thousands of multiple comparisons generated as part of a PheWAS. In this study, we developed an approach that maximizes the power to test for heterogeneous genotype-phenotype associations and applied this approach to an IL6R PheWAS among individuals of African (AFR) and European (EUR) ancestries. We identified 29 traits with differences in IL6R variant-phenotype associations, including a lower risk of type 2 diabetes in AFR (OR 0.96) vs EUR (OR 1.0, p-value for heterogeneity = 8.5 × 10-3), and higher white blood cell count (p-value for heterogeneity = 8.5 × 10-131). These data suggest a more salutary effect of IL6R blockade for T2D among individuals of AFR vs EUR ancestry and provide data to inform ongoing clinical trials targeting IL6 for an expanding number of conditions. Moreover, the method to test for heterogeneity of associations can be applied broadly to other large-scale genotype-phenotype screens in diverse populations.

BACKGROUND: Oxidized phospholipids play a key role in the atherogenic potential of lipoprotein(a) (Lp[a]); however, Lp(a) is a complex particle that warrants research into additional proinflammatory mediators. We hypothesized that additional Lp(a)-associated lipids contribute to the atherogenicity of Lp(a). METHODS: Untargeted lipidomics was performed on plasma and isolated lipoprotein fractions. The atherogenicity of the observed Lp(a)-associated lipids was tested ex vivo in primary human monocytes by RNA sequencing, ELISA, Western blot, and transendothelial migratory assays. Using immunofluorescence staining and single-cell RNA sequencing, the phenotype of macrophages was investigated in human atherosclerotic lesions. RESULTS: Compared with healthy individuals with low/normal Lp(a) levels (median, 7 mg/dL [18 nmol/L]; n=13), individuals with elevated Lp(a) levels (median, 87 mg/dL [218 nmol/L]; n=12) demonstrated an increase in lipid species, particularly diacylglycerols (DGs) and lysophosphatidic acid (LPA). DG and the LPA precursor lysophosphatidylcholine were enriched in the Lp(a) fraction. Ex vivo stimulation with DG(40:6) demonstrated a significant upregulation in proinflammatory pathways related to leukocyte migration, chemotaxis, NF-κB (nuclear factor kappa B) signaling, and cytokine production. Functional assessment showed a dose-dependent increase in the secretion of IL (interleukin)-6, IL-8, and IL-1β after DG(40:6) and DG(38:4) stimulation, which was, in part, mediated via the NLRP3 (NOD [nucleotide-binding oligomerization domain]-like receptor family pyrin domain containing 3) inflammasome. Conversely, LPA-stimulated monocytes did not exhibit an inflammatory phenotype. Furthermore, activation of monocytes by DGs and LPA increased their transendothelial migratory capacity. Human atherosclerotic plaques from patients with high Lp(a) levels demonstrated colocalization of Lp(a) with M1 macrophages, and an enrichment of CD68+IL-18+TLR4+ (toll-like receptor) TREM2+ (triggering receptor expressed on myeloid cells) resident macrophages and CD68+CASP1+ (caspase) IL-1B+SELL+ (selectin L) inflammatory macrophages compared with patients with low Lp(a). Finally, potent Lp(a)-lowering treatment (pelacarsen) resulted in a reduction in specific circulating DG lipid subspecies in patients with cardiovascular disease with elevated Lp(a) levels (median, 82 mg/dL [205 nmol/L]). CONCLUSIONS: Lp(a)-associated DGs and LPA have a potential role in Lp(a)-induced monocyte inflammation by increasing cytokine secretion and monocyte transendothelial migration. This DG-induced inflammation is, in part, NLRP3 inflammasome dependent.

BACKGROUND: Suicide is the second leading cause of death in 12- to 17-year-old adolescents in the USA. Research on biological mechanisms contributing to self-harm risk that could be targeted in treatment could help to prevent suicide and self-harm episodes. AIMS: We aimed to evaluate whether markers of inflammation, interleukin-6 (IL-6) and C-reactive protein (CRP), predict self-harm over 3 months within a sample selected for elevated suicide/self-harm risk at project entry. METHOD: Fifty-one adolescents aged 12-19 years selected for elevated suicide/self-harm risk completed three clinical interviews about suicide attempts and non-suicidal self-injury, 3 months apart. At baseline and 3 months, youth also provided blood samples, from which we assayed levels of IL-6 and CRP. RESULTS: Using generalised mixed models, we found that greater levels of IL-6 predicted more self-harm episodes (odds ratio [OR] = 3.3, 95% CI: 1.1, 10.0) and specifically, non-suicidal self-injury (OR = 3.5, 95% CI: 1.1, 11.2), over 3 months. CONCLUSIONS: The study findings increase our understanding of whether and how inflammation may be implicated in risk of self-harm. IL-6 may be a viable biological marker of short-term risk for self-harm.

BACKGROUND: In contrast to fine particles, less is known of the inflammatory and coagulation impacts of coarse particulate matter (PM10-2.5, particulate matter with aerodynamic diameter ≤10μm and>2.5μm). Toxicological research suggests that these pathways might be important processes by which PM10-2.5 impacts health, but there are relatively few epidemiological studies due to a lack of a national PM10-2.5 monitoring network. OBJECTIVES: We used new spatiotemporal exposure models to examine associations of both 1-y and 1-month average PM10-2.5 concentrations with markers of inflammation and coagulation. METHODS: We leveraged data from 7,071 Multi-Ethnic Study of Atherosclerosis and ancillary study participants 45-84 y of age who had repeated plasma measures of inflammatory and coagulation biomarkers. We estimated PM10-2.5 at participant addresses 1 y and 1 month before each of up to four exams (2000-2012) using spatiotemporal models that incorporated satellite, regulatory monitoring, and local geographic data and accounted for spatial correlation. We used random effects models to estimate associations with interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and D-dimer, controlling for potential confounders. RESULTS: Increases in PM10-2.5 were not associated with greater levels of inflammation or coagulation. A 10-μg/m3 increase in annual average PM10-2.5 was associated with a 2.5% decrease in CRP [95% confidence interval (CI): -5.5, 0.6]. We saw no association between annual average PM10-2.5 and the other markers (IL-6: -0.7%, 95% CI: -2.6, 1.2; fibrinogen: -0.3%, 95% CI: -0.9, 0.3; D-dimer: -0.2%, 95% CI: -2.6, 2.4). Associations consistently showed that a 10-μg/m3 increase in 1-month average PM10-2.5 was associated with reduced inflammation and coagulation, though none were distinguishable from no association (IL-6: -1.2%, 95% CI: -3.0 , 0.5; CRP: -2.5%, 95% CI: -5.3, 0.4; fibrinogen: -0.4%, 95% CI: -1.0, 0.1; D-dimer: -2.0%, 95% CI: -4.3, 0.3). DISCUSSION: We found no evidence that PM10-2.5 is associated with higher inflammation or coagulation levels. More research is needed to determine whether the inflammation and coagulation pathways are as important in explaining observed PM10-2.5 health impacts in humans as they have been shown to be in toxicology studies or whether PM10-2.5 might impact human health through alternative biological mechanisms. https://doi.org/10.1289/EHP12972.

This study examined the role that cytokines may have played in the beneficial outcomes found when outpatient individuals infected with SARS-CoV-2 were transfused with COVID-19 convalescent plasma (CCP) early in their infection. We found that the pro-inflammatory cytokine IL-6 decreased significantly faster in patients treated early with CCP. Participants with COVID-19 treated with CCP later in the infection did not have the same effect. This decrease in IL-6 levels after early CCP treatment suggests a possible role of inflammation in COVID-19 progression. The evidence of IL-6 involvement brings insight into the possible mechanisms involved in CCP treatment mitigating SARS-CoV-2 severity.

Considering the lack of consensus related to the impact of selective IL-6 receptor inhibition on bone remodeling and the scarcity of reports, especially on large bone defects, this study proposed to evaluate the biological impact of the selective inhibitor of interleukin-6 receptor (tocilizumab) in an experimental model of critical calvarial defect in rats. In this preclinical and in vivo study, 24 male Wistar rats were randomly divided into two groups (n=12/group): defect treated with collagen sponge (CG) and defect treated with collagen sponge associated with 2 mg/kg tocilizumab (TCZ). The defect in the parietal bone was created using an 8-mm diameter trephine drill. After 90 days, the animals were euthanized, and tissue samples (skull caps) were evaluated through micro-CT, histological, immunohistochemistry, cytokines, and RT-qPCR analyses. Tocilizumab reduced mononuclear inflammatory infiltration (P0.05). The bone cells (osteoblasts, osteoclasts, and osteocytes) in the defect area were similar in both groups (P>0.05). Tocilizumab reduced inflammatory cytokines, decreased osteogenic protein, and increased proteases in a critical bone defect in rats. Ninety days after the local application of tocilizumab in the cranial defect, we did not find a significant formation of bone tissue compared with a collagen sponge.

INTRODUCTION: IL6 signaling plays an important role in triggering labor and IL6 is an established biomarker of intrauterine infection/inflammation (IUI) driven preterm labor (PTL). The biology of IL6 during IUI at the maternal-fetal interface was investigated in samples from human subjects and non-human primates (NHP). METHODS: Pregnant women with histologic chorioamnionitis diagnosed by placenta histology were recruited (n=28 term, n=43 for preterm pregnancies from 26-36 completed weeks of gestation). IUI was induced in Rhesus macaque by intraamniotic injection of lipopolysachharide (LPS, n=23). IL1 signaling was blocked using Anakinra (human IL-1 receptor antagonist, n=13), and Tumor necrosis factor (TNF) signaling was blocked by anti TNF-antibody (Adalimumab n=14). The blockers were given before LPS. All animals including controls (intraamniotic injection of saline n=27), were delivered 16h after LPS/saline exposure at about 80% gestation. RESULTS: IUI induced a robust expression of IL6 mRNAs in the fetal membranes (chorion-amnion-decidua tissue) both in humans (term and preterm) and NHP. The major sources of IL6 mRNA expression were the amnion mesenchymal cells (AMC) and decidua stroma cells. Additionally, during IUI in the NHP, ADAM17 (a protease that cleaves membrane bound IL6 receptor (IL6R) to release a soluble form) and IL6R mRNA increased in the fetal membranes, and the ratio of IL6 and soluble forms of IL6R, gp130 increased in the amniotic fluid signifying upregulation of IL6 trans-signaling. Both IL1 and TNF blockade suppressed LPS-induced IL6 mRNAs in the AMC and variably decreased elements of IL6 trans-signaling. DISCUSSION: These data suggest that IL1 and TNF blockers may be useful anti-inflammatory agents via suppression of IL6 signaling at the maternal-fetal interface.

ObjectiveMany persons with opioid use disorders (OUDs) have HIV disease and experience clinically significant stress after they enroll in abstinence-based treatment and undergo medically assisted withdrawal. We examined whether opioid withdrawal affects virologic control, inflammatory markers, cognition, and mood in persons with an OUD and HIV, and explored whether measures of withdrawal stress, such as activation of the HPA axis, contribute to alterations in immune function, cognition, and mood.Method and participantsStudy participants were 53 persons with HIV who were admitted for OUD treatment at the City Addiction Hospital in Saint Petersburg, Russian Federation. Participants were examined at admission, at the anticipated peak of withdrawal 3 to 7 days after the last day of a clonidine-based withdrawal process lasting 7 to 14 days, and 3 to 4 weeks after completing withdrawal. At these times, participants received medical exams and were evaluated for symptoms of withdrawal, as well as cognition and mood. Viral load, plasma cortisol, DHEA sulfate ester (DHEA-S), interleukin-6 (IL-6), and soluble CD14 (sCD14) were determined. Multivariable models examined the relationships between markers of HPA activation and the other parameters over time.ResultsHPA activation as indexed by cortisol/DHEA-S ratio increased during withdrawal, as did markers of immune activation, IL-6 and sCD14. There were no significant associations between viral load and indicators of HPA activation. In longitudinal analyses, higher cortisol/DHEA sulfate was related to worse cognition overall, and more mood disturbance. Increase in IL-6 was associated with worse cognitive performance on a learning task. There were no significant associations with sCD14.ConclusionsWorsening of cognition and measures of mood disturbance during withdrawal were associated with activation of the HPA axis and some measures of inflammation. Whether repeated episodes of opioid withdrawal have a cumulative impact on long-term HIV outcomes and neurocognition is a topic for further investigation.

BACKGRUOUND: Phospholipase C-γ (PLC-γ) plays a crucial role in immune responses and is related to the pathogenesis of various inflammatory disorders. In this study, we investigated the role of PLC-γ and the therapeutic effect of the PLC-specific inhibitor U73122 using orbital fibroblasts from patients with Graves orbitopathy (GO). METHODS: The expression of phospholipase C gamma 1 (PLCG1) and phospholipase C gamma 2 (PLCG2) was evaluated using polymerase chain reaction in GO and normal orbital tissues/fibroblasts. The primary cultures of orbital fibroblasts were treated with non-toxic concentrations of U73122 with or without interleukin (IL)-1β to determine its therapeutic efficacy. The proinflammatory cytokine levels and activation of downstream signaling molecules were determined using Western blotting. RESULTS: PLCG1 and PLCG2 mRNA expression was significantly higher in GO orbital tissues than in controls (P

G protein-coupled receptors (GPCRs) are highly druggable and implicated in numerous diseases, including vascular inflammation. GPCR signals are transduced from the plasma membrane as well as from endosomes and controlled by posttranslational modifications. The thrombin-activated GPCR protease-activated receptor-1 is modified by ubiquitin. Ubiquitination of protease-activated receptor-1 drives recruitment of transforming growth factor-β-activated kinase-1-binding protein 2 (TAB2) and coassociation of TAB1 on endosomes, which triggers p38 mitogen-activated protein kinase-dependent inflammatory responses in endothelial cells. Other endothelial GPCRs also induce p38 activation via a noncanonical TAB1-TAB2-dependent pathway. However, the regulatory processes that control GPCR ubiquitin-driven p38 inflammatory signaling remains poorly understood. We discovered mechanisms that turn on GPCR ubiquitin-dependent p38 signaling, however, the mechanisms that turn off the pathway are not known. We hypothesize that deubiquitination is an important step in regulating ubiquitin-driven p38 signaling. To identify specific deubiquitinating enzymes (DUBs) that control GPCR-p38 mitogen-activated protein kinase signaling, we conducted a siRNA library screen targeting 96 DUBs in endothelial cells and HeLa cells. We identified nine DUBs and validated the function two DUBs including cylindromatosis and ubiquitin-specific protease-34 that specifically regulate thrombin-induced p38 phosphorylation. Depletion of cylindromatosis expression by siRNA enhanced thrombin-stimulated p38 signaling, endothelial barrier permeability, and increased interleukin-6 cytokine expression. Conversely, siRNA knockdown of ubiquitin-specific protease-34 expression decreased thrombin-promoted interleukin-6 expression and had no effect on thrombin-induced endothelial barrier permeability. These studies suggest that specific DUBs distinctly regulate GPCR-induced p38-mediated inflammatory responses.

Post-COVID conditions (PCCs) are common and have significant morbidity. Risk factors for PCC include advancing age, female sex, obesity, and diabetes mellitus. Little is known about treatment, inflammation, and PCC. Among 882 individuals with confirmed SARS-CoV-2 infection participating in a randomized trial of COVID-19 convalescent plasma (CCP) vs control plasma with available biospecimens and symptom data, the association between early CCP treatment, cytokine levels, and PCC was evaluated. Cytokine and chemokine levels were assessed at baseline, day 14, and day 90 using a multiplexed sandwich immunoassay (Meso Scale Discovery). Presence of any self-reported PCC symptoms was assessed at day 90. Associations between CCP treatment, cytokine levels, and PCC were examined using multivariate logistic regression models. One third of the 882 participants had day 90 PCC symptoms, with fatigue (14.5%) and anosmia (14.5%) being most common. Cytokine levels decreased from baseline to day 90. In a multivariable analysis, female sex (adjusted odds ratio [AOR] = 2.69 [1.93-3.81]), older age (AOR = 1.32 [1.17-1.50]), and elevated baseline levels of IL-6 (AOR = 1.59 [1.02-2.47]) were independently associated with development of PCC. Those who received early CCP treatment (≤5 days after symptom onset) compared to late CCP treatment had statistically significant lower odds of PCC. IMPORTANCE Approximately 20% of individuals infected with SARS-CoV-2 experienced long-term health effects, as defined PCC. However, it is unknown if there are any early biomarkers associated with PCC or whether early intervention treatments may decrease the risk of PCC. In a secondary analysis of a randomized clinical trial, this study demonstrates that among outpatients with SARS-CoV-2, increased IL-6 at time of infection is associated with increased odds of PCC. In addition, among individuals treated early, within 5 days of symptom onset, with COVID-19 convalescent plasma, there was a trend for decreased odds of PCC after adjusting for other demographic and clinical characteristics. Future treatment studies should be considered to evaluate the effect of early treatment and anti-IL-6 therapies on PCC development.

BACKGROUND: In the demyelinating disease multiple sclerosis (MS), chronic-active brain inflammation, remyelination failure and neurodegeneration remain major issues despite immunotherapy. While B cell depletion and blockade/sequestration of T and B cells potently reduces episodic relapses, they act peripherally to allow persistence of chronic-active brain inflammation and progressive neurological dysfunction. N-acetyglucosamine (GlcNAc) is a triple modulator of inflammation, myelination and neurodegeneration. GlcNAc promotes biosynthesis of Asn (N)-linked-glycans, which interact with galectins to co-regulate the clustering/signaling/endocytosis of multiple glycoproteins simultaneously. In mice, GlcNAc crosses the blood brain barrier to raise N-glycan branching, suppress inflammatory demyelination by T and B cells and trigger stem/progenitor cell mediated myelin repair. MS clinical severity, demyelination lesion size and neurodegeneration inversely associate with a marker of endogenous GlcNAc, while in healthy humans, age-associated increases in endogenous GlcNAc promote T cell senescence. OBJECTIVES AND METHODS: An open label dose-escalation mechanistic trial of oral GlcNAc at 6 g (n = 18) and 12 g (n = 16) for 4 weeks was performed in MS patients on glatiramer acetate and not in relapse from March 2016 to December 2019 to assess changes in serum GlcNAc, lymphocyte N-glycosylation and inflammatory markers. Post-hoc analysis examined changes in serum neurofilament light chain (sNfL) as well as neurological disability via the Expanded Disability Status Scale (EDSS). RESULTS: Prior to GlcNAc therapy, high serum levels of the inflammatory cytokines IFNγ, IL-17 and IL-6 associated with reduced baseline levels of a marker of endogenous serum GlcNAc. Oral GlcNAc therapy was safe, raised serum levels and modulated N-glycan branching in lymphocytes. Glatiramer acetate reduces TH1, TH17 and B cell activity as well as sNfL, yet the addition of oral GlcNAc dose-dependently lowered serum IFNγ, IL-17, IL-6 and NfL. Oral GlcANc also dose-dependently reduced serum levels of the anti-inflammatory cytokine IL-10, which is increased in the brain of MS patients. 30% of treated patients displayed confirmed improvement in neurological disability, with an average EDSS score decrease of 0.52 points. CONCLUSIONS: Oral GlcNAc inhibits inflammation and neurodegeneration markers in MS patients despite concurrent immunomodulation by glatiramer acetate. Blinded studies are required to investigate GlcNAcs potential to control residual brain inflammation, myelin repair and neurodegeneration in MS.

BACKGROUND: On the basis of the mounting evidence that type 17 T (T17) cells and increased IL-17 play a key role in driving hidradenitis suppurativa (HS) lesion development, biologic agents used previously in psoriasis that block signaling of IL-17A and/or IL-17F isoforms have been repurposed to treat HS. OBJECTIVE: Our research aimed to characterize the transcriptome of HS T17 cells compared to the transcriptome of psoriasis T17 cells, along with their ligand-receptor interactions with neighborhood immune cell subsets. METHODS: Single-cell data of 12,300 cutaneous immune cells from 8 deroofing surgical HS skin samples including dermal tunnels were compared to single-cell data of psoriasis skin (19,525 cells from 11 samples) and control skin (11,920 cells from 10 samples). All single-cell data were generated by the same protocol. RESULTS: HS T17 cells expressed lower levels of IL23R and higher levels of IL1R1 and IL17F compared to psoriasis T17 cells (P < .05). HS Treg cells expressed higher levels of IL1R1 and IL17F compared to psoriasis Treg cells (P < .05). Semimature dendritic cells were the major immune cell subsets expressing IL1B in HS, and IL-1β ligand-receptor interactions between semimature dendritic cells and T17 cells were increased in HS compared to psoriasis (P < .05). HS dermal tunnel keratinocytes expressed inflammatory cytokines (IL17C, IL1A, IL1B, and IL6) that differed from the HS epidermis keratinocytes (IL36G) (P < .05). IL6, which synergizes with IL1B to maintain cytokine expression in T17 cells, was mainly expressed by fibroblasts in HS, which also expressed IL11+ inflammatory fibroblast genes (IL11, IL24, IL6, and POSTN) involved in the paracrine IL-1/IL-6 loop. CONCLUSION: The IL-1β-T17 cell cytokine axis is likely a dominant pathway in HS with HS T17 cells activated by IL-1β signaling, unlike psoriasis T17 cells, which are activated by IL-23 signaling.

Many factors outside of cardiovascular health can impact the structure of white matter. Identification of reliable and clinically meaningful biomarkers of the neural effects of systemic and cardiovascular health are needed to refine etiologic predictions. We examined whether the corpus callosum demonstrates regional vulnerability to systemic cardiovascular risk factors. Three hundred and ninety-four older adults without dementia completed brain MRI, neurobehavioral evaluations, and blood draws. A subset (n = 126, n = 128) of individuals had blood plasma analyzed for inflammatory markers of interest (IL-6 and TNF-alpha). Considering diffusion tensor imaging (DTI) is a particularly reliable measure of white matter integrity, we utilized DTI to examine fractional anisotropy (FA) of anterior and posterior regions of the corpus callosum. Using multiple linear regression models, we simultaneously examined FA of the genu and the splenium to compare their associations with systemic and cardiovascular risk factors. Lower FA of the genu but not splenium was associated with greater systemic and cardiovascular risk, including higher systolic blood pressure (β = -0.17, p = .020), hemoglobin A1C (β = -0.21, p = .016) and IL-6 (β = -0.34, p = .005). FA of the genu was uniquely associated with cognitive processing speed (β = 0.20, p = .0015) and executive functioning (β = 0.15, p = .012), but not memory performances (β = 0.05, p = .357). Our results demonstrated differential vulnerability of the corpus callosum, such that frontal regions showed stronger, independent associations with biomarkers of systemic and cardiovascular health in comparison to posterior regions. Posterior white matter integrity may not reflect cardiovascular health. Clinically, these findings support the utility of examining the anterior corpus callosum as an indicator of cerebrovascular health.

ObjectiveResearch has established links between social isolation and heightened levels of proinflammatory cytokines (e.g., interleukin-6 [IL-6], tumour necrosis factor alpha [TNF-α]). Recent advances allow for the examination of cytokines that may also play a role in antiviral immunity (interferon-gamma [IFN-γ]). The present work explored how various features of social experience relate to circulating cytokines in breast cancer survivors, as inflammation has been tied to cancer recurrence and mortality.DesignFemale breast cancer survivors (N = 43) completed a blood draw to assess circulating levels of proinflammatory cytokines (IL-6, TNF-α) and levels of a cytokine that also relates to antiviral immunity (IFN-γ).Main outcome measuresWe examined associations between cytokines and different aspects of social experience, including household size, psychosocial well-being, and social threat anxiety.ResultsCirculating levels of IFN-γ were associated with larger household size (r = 0.32, p = 0.04) and higher levels of psychosocial well-being (r = 0.33, p = 0.04). Additionally, heightened levels of IL-6 were associated with social threat anxiety (r = 0.38, p = 0.01). Heightened IL-6 was also associated with household size (r = 0.33, p = 0.03).ConclusionThese findings are consistent with work suggesting that antiviral immunity and inflammation may have distinct contributions to the links between social experience and health, particularly for those previously diagnosed with breast cancer.

ContextEarlier studies have investigated the role of obesity-related inflammation and endogenous sex hormones in men. The role of interleukin-6 (IL-6) and C-reactive protein (CRP) with testosterone and sex hormone binding globulin (SHBG) levels in men is still debated.ObjectiveTo investigate the independent association between levels of high sensitivity CRP (hsCRP) and IL-6 with endogenous sex hormones in men.DesignCross-sectional observational study using data from the Multi-Ethnic Study of Atherosclerosis.Patients or other participantsA community-based sample of 3212 men aged 45-84 years was included. After exclusions, 3041 men remained for the analyses.Main outcome measure(s)Serum concentrations of testosterone, SHBG, hsCRP, IL-6, and sTNFR were measured from the baseline exam. Multivariable linear regressions were used to examine the association of inflammatory markers with sex hormones.ResultsAn inverse association was found between levels of hsCRP and levels of testosterone and SHBG, even after adjustment for confounders and IL-6 (Total Testosterone; B = -0.14, Bioavailable Testosterone; B = -0.06, and SHBG; B = -0.66). Similar results were found for IL-6, although a positive association was found for SHBG (B = 0.95). Notably, an inverse association was found for IL-6 with bioavailable testosterone in African Americans and Hispanic Americans aged 45-54 years. No associations were found for sTNFR and endogenous sex hormones.ConclusionOur results indicate that inflammatory markers have independent associations with levels of testosterone (total and bioavailable) and furthermore, appear to associate differently with SHBG levels.

BACKGROUND: Immune activation/inflammation markers (immune markers) were tested to explain differences in neurocognition among older breast cancer survivors versus noncancer controls. METHODS: Women >60 years old with primary breast cancer (stages 0-III) (n = 400) were assessed before systemic therapy with frequency-matched controls (n = 329) and followed annually to 60 months; blood was collected during annual assessments from 2016 to 2020. Neurocognition was measured by tests of attention, processing speed, and executive function (APE). Plasma levels of interleukin-6 (IL-6), IL-8, IL-10, tumor necrosis factor α (TNF-α), and interferon γ were determined using multiplex testing. Mixed linear models were used to compare results of immune marker levels by survivor/control group by time and by controlling for age, racial/ethnic group, cognitive reserve, and study site. Covariate-adjusted multilevel mediation analyses tested whether survivor/control group effects on cognition were explained by immune markers; secondary analyses examined the impact of additional covariates (e.g., comorbidity and obesity) on mediation effects. RESULTS: Participants were aged 60-90 years (mean, 67.7 years). Most survivors had stage I (60.9%) estrogen receptor-positive tumors (87.6%). Survivors had significantly higher IL-6 levels than controls before systemic therapy and at 12, 24, and 60 months (p ≤ .001-.014) but there were no differences for other markers. Survivors had lower adjusted APE scores than controls (p

BackgroundHIV infection leads to endothelial activation, promoting platelet adhesion, and accelerating atherosclerosis. Our goal was to determine whether biomarkers of endothelial activation and hemostasis/thrombosis were elevated in people with treated HIV (PWH) before myocardial infarction (MI).MethodsIn a case-control study nested within the CFAR Network of Integrated Clinical Systems (CNICS) cohort, we compared 69 adjudicated cases with type 1 MI with 138 controls matched for antiretroviral therapy regimen. We measured angiopoietin-1, angiopoietin-2 (ANG-2), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), von Willebrand factor, C-reactive protein (CRP), interleukin-6 (IL-6), plasminogen activation inhibitor-1, P-selectin, serum amyloid-A, soluble CD14, and apolipoprotein A1 in stored plasma. Conditional logistic regression identified associations with subsequent MI, with and without adjustment for Atherosclerotic Cardiovascular Disease (ASCVD) and Veterans Aging Cohort Study (VACS) scores.ResultsHigher IL-6 was associated with MI after adjustment for ASCVD score (adjusted odds ratio [AOR] 1.51, 95% confidence interval [95% CI]: 1.05 to 2.17 per standard-deviation-scaled log 2 increment). In a separate model adjusting for VACS score, higher ANG-2 (AOR 1.49, 95% CI: 1.04 to 2.14), higher CRP (AOR 1.45, 95% CI: 1.06 to 2.00), and higher IL-6 (AOR 1.68, 95% CI: 1.17 to 2.41) were associated with MI. In a sensitivity analysis excluding PWH with viral load ≥400 copies/mL, higher IL-6 remained associated with MI after adjustment for ASCVD score and after adjustment for VACS score.ConclusionsAmong PWH, higher levels of plasma IL-6, CRP, and ANG-2 predict subsequent type 1 MI, independent of conventional risk scores. IL-6 had the most consistent associations with type 1 MI, regardless of viral load suppression.

Study objectivesThe coexistence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) in a single individual, also known as overlap syndrome (OVS), is associated with higher cardiovascular risk and mortality than either OSA or COPD alone. However, the underlying mechanisms remain unclear. We hypothesized that patients with OVS have elevated systemic inflammatory biomarkers relative to patients with either disease alone, which could explain greater cardiovascular risk observed in OVS.MethodsWe included 255 participants in the study, 55 with COPD alone, 100 with OSA alone, 50 with OVS, and 50 healthy controls. All participants underwent a home sleep study, spirometry, and a blood draw for high-sensitivity C-reactive protein and total blood count analysis. In a randomly selected subset of 186 participants, inflammatory protein profiling was performed using Bio-Rad Bio-Plex Pro Human Cytokine 27-Plex Assays. Biomarker level differences across groups were identified using a mixed linear model.ResultsLevels of interleukin 6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), and granulocyte colony stimulating factor (G-CSF) were higher in participants with OVS and COPD compared with healthy controls and participants with OSA. Furthermore, participants with OVS had higher circulating levels of leukocytes and neutrophils than those with COPD, OSA, and controls.ConclusionsCOPD and OVS are associated with higher systemic inflammation relative to OSA and healthy controls. This work proposes the potential utilization of interleukin 6, granulocyte colony stimulating factor, and high-sensitivity C-reactive protein as screening biomarkers for COPD in patients with OSA. Inflammatory pathways may not fully explain the higher cardiovascular risk observed in OVS, indicating the need for further investigation.CitationSanchez-Azofra A, Gu W, Masso-Silva JA, et al. Inflammation biomarkers in OSA, chronic obstructive pulmonary disease, and chronic obstructive pulmonary disease/OSA overlap syndrome. J Clin Sleep Med. 2023;19(8):1447-1456.

PURPOSE: Graves orbitopathy (GO) is an orbital manifestation of autoimmune Graves disease, and orbital fibroblast is considered a target cell, producing pro-inflammatory cytokines and/or differentiating into adipocytes. Adipose tissue has been focused on as an endocrine and inflammatory organ secreting adipokines. We investigated the pathogenic role of a specific adipokine, adipsin, known as complement factor D in Graves orbital fibroblasts. METHODS: The messenger RNA (mRNA) expression of multiple adipokines was investigated in adipose tissues harvested from GO and healthy subjects. Adipsin protein production was analyzed in primary cultured orbital fibroblasts under insulin growth factor (IGF)-1, CD40 ligand (CD40L) stimulation, and adipogenesis. The effect of blocking adipsin with small interfering RNA (siRNA) on pro-inflammatory cytokine production and adipogenesis was evaluated using quantitative real-time PCR, Western blot, and ELISA. Adipogenic differentiation was identified using Oil Red O staining. RESULTS: Adipsin gene expression was significantly elevated in GO tissue and increased after the stimulation of IGF-1 and CD40L, as well as adipocyte differentiation in GO cells. Silencing of adipsin suppressed IGF-1-induced IL-6, IL-8, COX2, ICAM-1, CCL2 gene expression, and IL-6 protein secretion. Adipsin suppression also attenuated adipocyte differentiation. Exogenous treatment of recombinant adipsin resulted in the activation of the Akt, ERK, p-38, and JNK signaling pathways. CONCLUSIONS: Adipsin, secreted by orbital fibroblasts, may play a distinct role in the pathogenesis of GO. Inhibition of adipsin ameliorated the production of pro-inflammatory cytokines and adipogenesis in orbital fibroblasts. Our study provides an in vitro basis suggesting adipsin as a potential therapeutic target for GO treatment.

Studies have shown ketogenic diets (KD) started from early middle-age improved health span and longevity in mice. KDs started later in life or administered intermittently may be more feasible and promote compliance. Therefore, this study sought to test if continuous or intermittent KDs started in late-middle-aged mice would improve cognition and motor function at advanced age. Eighteen-month-old male C57BL/6JN mice were assigned to an isocaloric control (CD), KD, or intermittent ketogenic (IKD, 3-day KD/week) diet. A panel of behavior tests were performed to assess cognitive and motor functions with aging. Y-maze alternation rate was higher for both IKD and KD mice at 23 months of age and for KD mice at 26 months indicating an improved spatial working memory. Twenty-six-month-old KD mice also showed better spatial learning memory in Barnes maze when compared to the CD. Improved grid wire hang performance was observed in aged IKD and KD versus CD mice indicating better muscle endurance under isometric contraction. A reduced level of circulating proinflammatory cytokines in aged KD (IL-6 and TNF-α) and IKD (IL-6) mice may contribute to the phenotypic improvements observed with these interventions. This study demonstrates that when initiated at late-middle age, the KD improved measures of spatial memory and grid wire hang performance in aged male mice, with IKD showing results intermediate to the CD and KD groups.

BACKGROUND: Measuring systemic inflammatory markers may improve clinical prognosis and help identify targetable pathways for treatment in patients with autosomal dominant forms of frontotemporal lobar degeneration (FTLD). METHODS: We measured plasma concentrations of IL-6, TNFα and YKL-40 in pathogenic variant carriers (MAPT, C9orf72, GRN) and non-carrier family members enrolled in the ARTFL-LEFFTDS Longitudinal Frontotemporal Lobar Degeneration consortium. We evaluated associations between baseline plasma inflammation and rate of clinical and neuroimaging changes (linear mixed effects models with standardised (z) outcomes). We compared inflammation between asymptomatic carriers who remained clinically normal (asymptomatic non-converters) and those who became symptomatic (asymptomatic converters) using area under the curve analyses. Discrimination accuracy was compared with that of plasma neurofilament light chain (NfL). RESULTS: We studied 394 participants (non-carriers=143, C9orf72=117, GRN=62, MAPT=72). In MAPT, higher TNFα was associated with faster functional decline (B=0.12 (0.02, 0.22), p=0.02) and temporal lobe atrophy. In C9orf72, higher TNFα was associated with faster functional decline (B=0.09 (0.03, 0.16), p=0.006) and cognitive decline (B=-0.16 (-0.22, -0.10), p

Adolescents' suicidal behavior frequently is preceded by interpersonal stress, but not all who experience distress attempt to end their lives. Recent theories have posited individual differences in stress-related inflammatory reactivity may be associated with psychopathology risk; this study examined inflammatory reactivity as a moderator of the prospective association between interpersonal stress and adolescents' suicidal behavior. Participants included 157 at-risk adolescent females (ages 12 to 16 years) and assessed individual differences in proinflammatory cytokine responses to a brief laboratory-based social stressor, both interpersonal and non-interpersonal life events, and suicidal behavior over an 18-month follow-up period. Measuring levels of the key proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) before and after an experimentally-induced social stressor, results revealed that blunted cytokine reactivity heightened the effect of high interpersonal stress exposure on risk for suicidal behaviors over the subsequent 9 months. Significant effects were not revealed for non-interpersonally themed stress. Finding highlight the urgent need for more research examining inflammation reactivity among adolescents.

BackgroundWe established a novel diethylnitrosamine (DEN) -induced mouse model that reflected the progression of cholangiocarcinoma (CCA) from atypical cystic hyperplasia.MethodsBALB/c mice were administered DEN by oral gavage. Cells isolated from livers were analyzed for expression of CSNK2A1, MAX and MAX-interacting proteins. Human CCA cell lines (MzChA-1, HuCCT1), normal human cholangiocyte (H69), human hepatic stellate cells (LX-2), macrophages (RAW 264.7), and primary hepatic cells were used for cellular and molecular biology assays.ResultsExpression of MAX, CSNK2A1, C-MYC, β-catenin, HMGB1, and IL-6 was upregulated in hepatic cells from CCA liver tissue. The half-life of MAX is higher in CCA cells, and this favors their proliferation. Overexpression of MAX increased growth, migration, and invasion of MzChA-1, whereas silencing of MAX had the opposite effect. MAX positively regulated IL-6 and HMGB1 through paracrine signaling in HepG2, LX2, and RAW cells and autocrine signaling in MzChA-1 cells. CSNK2A1-mediated MAX phosphorylation shifts MAX-MAX homodimer to C-MYC-MAX and β-catenin-MAX heterodimers and increases the HMGB1 and IL-6 promoter activities. Increase of MAX phosphorylation promotes cell proliferation, migration, invasion, and cholangiocarcinogenesis. The casein kinase 2 inhibitor CX-4945 induces cell cycle arrest and inhibits cell proliferation, migration, invasion, and carcinogenesis in MzChA-1 cells through the downregulation of CSNK2A1, MAX, and MAX-interaction proteins.ConclusionC-MYC-MAX and β-catenin-MAX binding to E-box site or β-catenin-MAX bound to TCFs/LEF1 enhanced HMGB1 or IL-6 promoter activities, respectively. IL-6 and HMGB1 secreted by hepatocytes, HSCs, and KCs exert paracrine effects on cholangiocytes to promote cell growth, migration, and invasion and lead to the progression of cholangiocarcinogenesis. CX-4945 provides perspectives on therapeutic strategies to attenuate progression from atypical cystic hyperplasia to cholangiocarcinogenesis.

BackgroundWe previously reported an association between household chemical exposures and an increased risk of paediatric-onset multiple sclerosis.MethodsUsing a case-control paediatric multiple sclerosis study, gene-environment interaction between exposure to household chemicals and genotypes for risk of paediatric-onset multiple sclerosis was estimated.Genetic risk factors of interest included the two major HLA multiple sclerosis risk factors, the presence of DRB1*15 and the absence of A*02, and multiple sclerosis risk variants within the metabolic pathways of common household toxic chemicals, including IL-6 (rs2069852), BCL-2 (rs2187163) and NFKB1 (rs7665090).Results490 paediatric-onset multiple sclerosis cases and 716 controls were included in the analyses. Exposures to insect repellent for ticks or mosquitos (OR 1.47, 95% CI 1.06 to 2.04, p=0.019), weed control products (OR 2.15, 95% CI 1.51 to 3.07, p

ObjectiveChronic stress adversely affects cognition, in part due to stress-induced inflammation. Rodent models suggest females are more resilient against stress-related cognitive dysfunction than males; however, few studies have examined this in humans. We examined sex differences in the relationship between perceived stress, cognitive functioning, and peripheral inflammation over time among cognitively normal older adults.DesignLongitudinal observational study.SettingUniversity research center.Participants274 community-dwelling older adults (baseline age: M=70.7, SD=7.2; 58% women; Clinical Dementia Rating=0) who completed at least two study visits.MeasurementsNeurocognitive functioning and perceived stress (Perceived Stress Scale [PSS]) were assessed at each visit. Plasma was analyzed for interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in a subset of 147 participants. Linear mixed effects models examined the interaction between average PSS (i.e., averaged within persons across visits), sex, and time on cognitive domains and on inflammatory markers.ResultsThe interaction between stress, sex, and time predicted executive functioning (β = 0.26, SE = 0.10, p = 0.01) such that higher average PSS related to steeper declines in men, but not in women. Among the 147 participants with inflammatory data, higher average PSS was associated with steeper increases in IL-6 over time in men, but not in women.ConclusionConsistent with animal models, results showed older men were more vulnerable to negative effects of stress on cognitive aging, with domain-specific declines in executive function. Findings also suggest systemic immunological mechanisms may underlie increased risk for cognitive decline in men with higher levels of stress. Future work is needed to examine the potential efficacy of person-specific stress interventions.

BACKGROUND: The role of the hypothalamic-pituitary-adrenal (HPA) axis in human aggressive behavior is poorly characterized, though some studies report that, unlike depression, circulating or salivary levels of cortisol are low compared with controls. METHODS: In this study, we collected three salivary cortisol levels (two in the morning and one in the evening) on three separate days in 78 adult study participants with (n = 28) and without (n = 52) prominent histories of impulsive aggressive behavior. Plasma C-Reactive Protein (CRP) and Interleukin-6 (IL-6) were also collected in most study participants. Aggressive study participants meet DSM-5 criteria for Intermittent Explosive Disorder (IED) while non-aggressive participants either had a history of a psychiatric disorder or no such history (Controls). RESULTS: Morning, but not evening, salivary cortisol levels were significantly lower in IED (p

AbstractSleep loss heightens pain sensitivity, but the pathways underlying this association are not known. Given that experimental sleep disruption induces increases in cellular inflammation as well as selective loss of slow wave, N3 sleep, this study examined whether these mechanisms contribute to pain sensitivity following sleep loss in healthy adults. This assessor-blinded, cross-over sleep condition, single-site, randomized clinical trial enrolled 95 healthy adults (mean [SD] age, 27.8 [6.4]; female, 44 [53.7%]). The 2 sleep conditions were 2 nights of undisturbed sleep (US) and 2 nights of sleep disruption or forced awakening (FA, 8 pseudorandomly distributed awakenings and 200 minutes wake time during the 8-hour sleep opportunity), administered in a cross-over design after 2 weeks of washout and in a random order (FA-US; US-FA). Primary outcome was heat pain threshold (hPTH). Sleep architecture was assessed by polysomnography, and morning levels of cellular inflammation were evaluated by Toll-like receptor-4 stimulated monocyte intracellular proinflammatory cytokine production. As compared with US, FA was associated with decreases in the amount of slow wave or N3 sleep ( P < 0.001), increases in Toll-like receptor-4 stimulated production of interleukin-6 and tumor necrosis factor-α ( P = 0.03), and decreases in hPTH ( P = 0.02). A comprehensive causal mediation analysis found that FA had an indirect effect on hPTH by decreases in N3 sleep and subsequent increases in inflammation (estimate=-0.15; 95% confidence interval, -0.30 to -0.03; P < 0.05) with the proportion mediated 34.9%. Differential loss of slow wave, N3 sleep, and increases in cellular inflammation are important drivers of pain sensitivity after sleep disruption.Clinical Trials Registration: NCT01794689.

BackgroundMethamphetamine (MA) use is associated with sexual risk behavior as well as systemic and mucosal inflammation, suggesting parallel biological and behavioral mechanisms of HIV transmission among men who have sex with men (MSM) who use MA. Data evaluating the combined biological effects of MA use with concomitant rectal gonococcal and/or chlamydial (GC/CT) infection on inflammation are limited.SettingSecondary analysis of stored rectal and plasma specimens from 100 MSM participating in an NIDA-funded longitudinal cohort in Los Angeles, CA.MethodsThis cross-sectional analysis evaluated systemic and rectal inflammatory markers under 2 conditions: (1) recent MA use (by urine drug screen) and (2) rectal GC/CT infection. We evaluated 50 participants with recent MA use (25 with and 25 without rectal GC/CT) and 50 MSM without MA use (25 with and 25 without rectal GC/CT). Log-transformed plasma and rectal immune markers were regressed on MA exposure and rectal GC/CT, controlling for HIV status and age.ResultsMedian age was 32 (range 19-45) years, and 58% of participants were living with HIV. Plasma tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, IL-1ß, and rectal IL-6 were associated with rectal GC/CT and MA use, independent of HIV status. Higher levels of rectal TNF-α, IL-1ß, and IL-17a were associated with rectal GC/CT.ConclusionsSystemic and rectal inflammation was positively associated with rectal GC/CT and MA use. Condomless sex in the setting of GC/CT- and MA-induced immune activation may provide a basis for synergistic biobehavioral mechanisms that promote HIV/STI transmission among MSM who use MA.

INTRODUCTION: Individuals with greater affect variability (i.e., moment-to-moment fluctuations possibly reflecting emotional dysregulation) are at risk for greater systemic inflammation, which is associated with cardiovascular disease. Some evidence suggests that affect variability is linked with poorer health indicators only among those with higher average levels of affect, particularly for positive affect (PA), and that associations may be non-linear. The present study sought to examine whether links between both PA and negative affect (NA) variability and inflammation are moderated by average level of affect. METHODS: Participants (N = 300, 50 % female, ages 21-70, 60 % non-Hispanic White, 19 % Hispanic, 15 % non-Hispanic Black) completed a lab assessment and provided a blood sample to measure systemic inflammation (i.e., TNF-α, IL-6, CRP). Affect was collected via a two-day ecological momentary assessment protocol where reports were collected about every 45-min during waking hours. Momentary affect ratings were averaged across both days (i.e., iM), separately for PA and NA, for each participant. Affect variability was calculated as the person-specific SD (i.e., iSD) of affect reports, separately for PA and NA. Linear and quadratic interactions were tested. Models included covariates for sex, race, and body mass index. RESULTS: There were significant interactions between NA iM and NA iSD predicting TNF-α (b = 6.54; p

BACKGROUND: Early life adversity (ELA) has long been associated with increased risk for stress-related psychopathology, particularly depression. The neuroimmune network hypothesis posits that ELA increases sensitivity to psychosocial stress, moderating the association between increases in peripheral markers of inflammation and decreases in reward outcomes linked to anhedonia and risk-taking behaviors. The present study examined this hypothesis in a sample of adolescents by using acute psychosocial stress to probe the role of inflammatory signaling in behavioral measures of reward and risk processing. METHOD: 80 adolescents [13.86 years (SD = 1.54); 45 % female], oversampled for ELA, underwent the Trier Social Stress Test for Children while providing blood samples immediately before and 60-minutes after stress onset. Blood samples were assayed for plasma IL-6. One hour before stress onset, and then 60 min after, participants completed computer-administered behavioral tasks measuring reward (Pirate Task) and risk (Balloon Analog Risk Task). RESULTS: ELA moderated the association between increases in IL-6 and decreases in risk tolerance in pursuit of rewards (p = 0.003) and reward response bias (p = 0.04). Stress-induced increases in IL-6 were associated with decreases in pumps for rewards among adolescents exposed to high, relative to little or no, ELA. Further, greater IL-6 increases were associated with increases in bias toward high relative to low value rewards among adolescents with low adversity exposure but not among those exposed to higher adversity. CONCLUSIONS: The present study provides the first evidence in a pediatric sample that ELA may alter the role of stress-induced inflammation in reward and risk processing, and may extend our understanding of why stress leads to depression in this high-risk population.

Complex bidirectional cross talk between adipocytes and adipose tissue immune cells plays an important role in regulating adipose function, inflammation, and insulin responsiveness. Adipocytes secrete the pleiotropic cytokine IL-6 in response to both inflammatory and catabolic stimuli. Previous studies have suggested that IL-6 secretion from adipocytes in obesity may promote adipose tissue inflammation. Here, we investigated catabolic stimulation of adipocyte IL-6 secretion and its impact on adipose tissue immune cells. In obesity, catecholamine resistance reduces cAMP-driven adipocyte IL-6 secretion in response to catabolic signals. By restoring adipocyte catecholamine sensitivity in obese adipocytes, amlexanox stimulates adipocyte-specific IL-6 secretion. We report that in this context, adipocyte-secreted IL-6 activates local macrophage STAT3 to promote Il4ra expression, thereby sensitizing them to IL-4 signaling and promoting an anti-inflammatory gene expression pattern. Supporting a paracrine adipocyte to macrophage mechanism, these effects could be recapitulated using adipocyte conditioned media to pretreat bone marrow-derived macrophages prior to polarization with IL-4. The effects of IL-6 signaling in adipose tissue are complex and context specific. These results suggest that cAMP-driven IL-6 secretion from adipocytes sensitizes adipose tissue macrophages to IL-4 signaling.

The impact of tobacco cigarette (TCIG) smoking and electronic cigarette (ECIG) vaping on the risk of development of severe COVID-19 is controversial. The present study investigated levels of proteins important for SARS-CoV-2 pathogenesis present in plasma because of ectodomain shedding in smokers, ECIG vapers, and non-smokers (NSs). Protein levels of soluble angiotensin-converting enzyme 2 (ACE2), angiotensin (Ang) II (the ligand of ACE2), Ang 1-7 (the main peptide generated from Ang II by ACE2 activity), furin (a protease that increases the affinity of the SARS-CoV-2 spike protein for ACE2), and products of ADAM17 shedding activity that predict morbidity in COVID-19 (IL-6/IL-6R alpha (IL-6/IL-6Rα) complex, soluble CD163 (sCD163), L-selectin) were determined in plasma from 45 NSs, 30 ECIG vapers, and 29 TCIG smokers using ELISA. Baseline characteristics of study participants did not differ among groups. TCIG smokers had increased sCD163, L-selectin compared to NSs and ECIG vapers (p  0.1 for all comparisons). Further studies are needed to determine if increased furin activity and ADAM17 shedding activity that is associated with increased plasma levels of sCD163 and L-selectin in healthy young TCIG smokers may contribute to the future development of severe COVID-19 and cardiovascular complications of post-acute COVID-19 syndrome.

BackgroundPotassium channels (KCa3.1; Kv1.3; Kir2.1) are necessary for microglial activation, a pivotal requirement for the development of Perioperative Neurocognitive Disorders (PNDs). We previously reported on the role of microglial Kv1.3 for PNDs; the present study sought to determine whether inhibiting KCa3.1 channel activity affects neuroinflammation and prevents development of PND.MethodsMice (wild-type [WT] and KCa3.1-/-) underwent aseptic tibial fracture trauma under isoflurane anesthesia or received anesthesia alone. WT mice received either TRAM34 (a specific KCa3.1 channel inhibitor) dissolved in its vehicle (miglyol) or miglyol alone. Spatial memory was assessed in the Y-maze paradigm 6 h post-surgery/anesthesia. Circulating interleukin-6 (IL-6) and high mobility group box-1 protein (HMGB1) were assessed by ELISA, and microglial activitation Iba-1 staining.ResultsIn WT mice surgery induced significant cognitive decline in the Y-maze test, p = 0.019), microgliosis (p = 0.001), and increases in plasma IL-6 (p = 0.002) and HMGB1 (p = 0.001) when compared to anesthesia alone. TRAM34 administration attenuated the surgery-induced changes in cognition, microglial activation, and HMGB1 but not circulating IL-6 levels. In KCa3.1-/- mice surgery neither affected cognition nor microgliosis, although circulating IL-6 levels did increase (p

ObjectivesTo determine in patients with acute respiratory distress syndrome (ARDS) on venovenous extracorporeal membrane oxygenation (VV ECMO) whether reducing driving pressure (ΔP) would decrease plasma biomarkers of inflammation and lung injury (interleukin-6 [IL-6], IL-8, and the soluble receptor for advanced glycation end-products sRAGE).DesignA single-center prospective physiologic study.SettingAt a single university medical center.ParticipantsAdult patients with severe COVID-19 ARDS on VV ECMO.InterventionsParticipants on VV ECMO had the following biomarkers measured: (1) pre-ECMO with low-tidal-volume ventilation (LTVV), (2) post-ECMO with LTVV, (3) during low-driving-pressure ventilation (LDPV), (4) after 2 hours of very low driving-pressure ventilation (V-LDPV, main intervention ΔP = 1 cmH2O), and (5) 2 hours after returning to LDPV.Main measurements and resultsTwenty-six participants were enrolled; 21 underwent V-LDPV. There was no significant change in IL-6, IL-8, and sRAGE from LDPV to V-LDPV and from V-LDPV to LDPV. Only participants (9 of 21) with nonspontaneous breaths had significant change (p < 0.001) in their tidal volumes (Vt) (mean ± SD), 1.9 ± 0.5, 0.1 ± 0.2, and 2.0 ± 0.7 mL/kg predicted body weight (PBW). Participants with spontaneous breathing, Vt were unchanged-4.5 ± 3.1, 4.7 ± 3.1, and 5.6 ± 2.9 mL/kg PBW (p = 0.481 and p = 0.065, respectively). There was no relationship found when accounting for Vt changes and biomarkers.ConclusionsBiomarkers did not significantly change with decreased ΔPs or Vt changes during the first 24 hours post-ECMO. Despite deep sedation, reductions in Vt during V-LDPV were not reliably achieved due to spontaneous breaths. Thus, patients on VV ECMO for ARDS may have higher Vt (ie, transpulmonary pressure) than desired despite low ΔPs or Vt.

PurposeProstate cancer (PCa) is the most commonly diagnosed cancer in men, resulting in a large cancer burden given a relatively higher 5-year survival rate of patients after cancer diagnosis. The underlying etiology of prostate cancer is not well understood. Chronic inflammation plays a significant role in carcinogenesis overall and may be involved in the development of PCa, but immune-related biomarker studies in prostate cancer are limited.MethodsThe associations of serum concentrations of cytokines, systemic immune biomarkers, with risk of PCa were assessed in a randomly selected sub-cohort (n = 798, mean age = 73 years) of the Osteoporotic Fractures in Men (MrOS) study, a prospective cohort of older men. At baseline, we measured serum interleukin (IL)-6, C-reactive protein (CRP), tumor necrosis factor alpha (TNFα), soluble receptors (SR) of IL-6 (IL-6SR) and TNF (TNFαSR1 and TNFαSR2), and IL-10. The risk of PCa was calculated for higher tertile levels of measured individual cytokines relative to the lowest tertile using Cox proportional hazards regression models.ResultsAfter an average 6 years of follow-up, 59 men developed incident PCa. Men in the middle or highest tertile of IL-10 had a statistically significant 50% lower risk of PCa compared to the lowest tertile (hazard ratio = 0.50, 95% confidence interval = 0.30-0.84). There was no significant association between any of the other cytokines measured and PCa risk.ConclusionIL-10, an anti-inflammatory cytokine, was associated with lower risk of PCa. Further research of IL-10 and inflammation in relation to PCa development is warranted.

IntroductionPeriodontitis-related oral microbial dysbiosis is thought to contribute to Alzheimer's disease (AD) neuroinflammation and brain amyloid production. Since probiotics can modulate periodontitis/oral dysbiosis, this study examined the effects of a probiotic/lantibiotic, nisin, in modulating brain pathology triggered by periodontitis.MethodsA polymicrobial mouse model of periodontal disease was used to evaluate the effects of this disease on brain microbiome dysbiosis, neuroinflammation, Alzheimer's-related changes, and nisin's therapeutic potential in this context.Results16S sequencing and real-time PCR data revealed that Nisin treatment mitigated the changes in the brain microbiome composition, diversity, and community structure, and reduced the levels of periodontal pathogen DNA in the brain induced by periodontal disease. Nisin treatment significantly decreased the mRNA expression of pro-inflammatory cytokines (Interleukin-1β/IL-1 β, Interleukin 6/IL-6, and Tumor Necrosis Factor α/TNF-α) in the brain that were elevated by periodontal infection. In addition, the concentrations of amyloid-β 42 (Aβ42), total Tau, and Tau (pS199) (445.69 ± 120.03, 1420.85 ± 331.40, 137.20 ± 36.01) were significantly higher in the infection group compared to the control group (193.01 ± 31.82, 384.27 ± 363.93, 6.09 ± 10.85), respectively. Nisin treatment markedly reduced the Aβ42 (261.80 ± 52.50), total Tau (865.37 ± 304.93), and phosphorylated Tau (82.53 ± 15.77) deposition in the brain of the infection group.DiscussionNisin abrogation of brain microbiome dysbiosis induces beneficial effects on AD-like pathogenic changes and neuroinflammation, and thereby may serve as a potential therapeutic for periodontal-dysbiosis-related AD.

Kaposi sarcoma-associated herpesvirus (KSHV) inflammatory cytokine syndrome (KICS) is a newly described chronic inflammatory disease condition caused by KSHV infection and is characterized by high KSHV viral load and sustained elevations of serum KSHV-encoded IL-6 (vIL-6) and human IL-6 (hIL-6). KICS has significant immortality and greater risks of other complications, including malignancies. Although prolonged inflammatory vIL-6 exposure by persistent KSHV infection is expected to have key roles in subsequent disease development, the biological effects of prolonged vIL-6 exposure remain elusive. Using thiol(SH)-linked alkylation for the metabolic (SLAM) sequencing and Cleavage Under Target & Release Using Nuclease analysis (CUT&RUN), we studied the effect of prolonged vIL-6 exposure in chromatin landscape and resulting cytokine production. The studies showed that prolonged vIL-6 exposure increased Bromodomain containing 4 (BRD4) and histone H3 lysine 27 acetylation co-occupancies on chromatin, and the recruitment sites were frequently co-localized with poised RNA polymerase II with associated enzymes. Increased BRD4 recruitment on promoters was associated with increased and prolonged NF-κB p65 binding after the lipopolysaccharide stimulation. The p65 binding resulted in quicker and sustained transcription bursts from the promoters; this mechanism increased total amounts of hIL-6 and IL-10 in tissue culture. Pretreatment with the BRD4 inhibitors, OTX015 and MZ1, eliminated the enhanced inflammatory cytokine production. These findings suggest that persistent vIL-6 exposure may establish a chromatin landscape favorable for the reactivation of inflammatory responses in monocytes. This epigenetic memory may explain the greater risk of chronic inflammatory disease development in KSHV-infected individuals.

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic double-stranded DNA virus and the etiologic agent of Kaposi's sarcoma and hyperinflammatory lymphoproliferative disorders. Understanding the mechanism by which KSHV increases the infected cell population is crucial for curing KSHV-associated diseases. Using scRNA-seq, we demonstrate that KSHV preferentially infects CD14+ monocytes, sustains viral lytic replication through the viral interleukin-6 (vIL-6), which activates STAT1 and 3, and induces an inflammatory gene expression program. To study the role of vIL-6 in monocytes upon KSHV infection, we generated recombinant KSHV with premature stop codon (vIL-6(-)) and its revertant viruses (vIL-6(+)). Infection of the recombinant viruses shows that both vIL-6(+) and vIL-6(-) KSHV infection induced indistinguishable host anti-viral response with STAT1 and 3 activations in monocytes; however, vIL-6(+), but not vIL-6(-), KSHV infection promoted the proliferation and differentiation of KSHV-infected monocytes into macrophages. The macrophages derived from vIL-6(+) KSHV infection showed a distinct transcriptional profile of elevated IFN-pathway activation with immune suppression and were compromised in T-cell stimulation function compared to those from vIL-6(-) KSHV infection or uninfected control. Notably, a viral nuclear long noncoding RNA (PAN RNA), which is required for sustaining KSHV gene expression, was substantially reduced in infected primary monocytes upon vIL-6(-) KSHV infection. These results highlight the critical role of vIL-6 in sustaining KSHV transcription in primary monocytes. Our findings also imply a clever strategy in which KSHV utilizes vIL-6 to secure its viral pool by expanding infected monocytes via differentiating into longer-lived dysfunctional macrophages. This mechanism may facilitate KSHV to escape from host immune surveillance and to support a lifelong infection.

INTRODUCTION: Extracts and compounds isolated from hemp (Cannabis sativa) are increasingly gaining popularity in the treatment of a number of diseases, with topical formulations for dermatological conditions leading the way. Phytocannabinoids such as ( )-cannabidiol, ( )-cannabinol and ( )-Δ9-tetrahydrocannabivarin (CBD, CBN, and THCV, respectively), are present in variable amounts in the plant, and have been shown to have mostly anti-inflammatory effects both in vitro and in vivo, albeit dominantly in murine models. The role of phytocannabinoids in regulating responses of dendritic cells (DCs) remains unclear. METHODS: Our research aimed to investigate the effects of CBD, CBN, and THCV on human DCs differentiated from monocytes (moDCs). moDCs were treated with up to 10 μM of each phytocannabinoid, and their effects on viability, differentiation, and maturation were assessed both alone, and in conjunction with TLR agonists. The effects of CBD on cytokine production, T cell activation and polarization as well as the transcriptome of moDCs was also determined. RESULTS: Phytocannabinoids did not influence the viability of moDCs up to 10 μM, and only CBD had effects on maturational markers of moDCs, and neither compound influenced LPS-induced activation at 10 μM. Since only CBD had measurable effects on moDCs, in our subsequent experiments we tested the effect only of that pCB. On moDCs differentiated in the presence of CBD subsequent activation by LPS induced a markedly different, much more tolerogenic response. CBD-treated moDCs also produced significantly more interleukin (IL)-6, TNFα and, importantly, IL-10 in response to LPS, which shows a shift toward anti-inflammatory signaling, as well as a more robust secretory response in general. To rule out the possibility that these effects of CBD are specific to TLR4 signaling, we determined the effect of CBD on TLR7/8-induced maturation as well, and saw similar, although less marked responses. CBD-treated moDCs were also less efficient at activating naïve T cells after LPS stimulation, further supporting the tolerogenic effect of this phytocannabinoid on moDCs. Reactome pathway analysis showed an inflammatory response to LPS in moDCs, and to a lesser extent to CBD as well. In contrast CBD-treated moDCs responded to LPS with a shift towards a more tolerogenic phenotype, as IL-10 signaling was the most prominently induced pathway in this group. DISCUSSION: Our results show that CBD achieves an anti-inflammatory effect on adaptive immune responses only in the presence of an activating stimuli on moDCs by reprogramming cells during long-term treatment, and not through acute, short-term effects.

Host immune responses play a key role in COVID-19 pathogenesis. The underlying phenomena are orchestrated by signaling molecules such as cytokines/chemokines and lipid mediators. These immune molecules, including anti-SARS-CoV-2 antibodies, interact with immune cells and regulate host responses, contributing to inflammation that drives the disease. We investigated 48 plasma cytokines/chemokines, 21 lipid mediators, and anti-S protein (RBD) antibodies in COVID-19 patients (n = 56) and non-COVID-19 respiratory disease controls (n = 49), to identify immune-biomarker profiles. Cytokines/chemokines (IL-6, CXCL-10 (IP-10), HGF, MIG, MCP-1, and G-CSF) and lipid mediators (TxB2, 11-HETE, 9-HODE, 13-HODE, 5-HETE, 12-HETE, 15-HETE, 14S-HDHA, 17S-HDHA, and 5-oxo ETE) were significantly elevated in COVID-19 patients compared to controls. In patients exhibiting severe disease, pro-inflammatory cytokines/chemokines (IL-6, CXCL-10, and HGF) and anti-SARS-CoV-2 antibodies were significantly elevated. In contrast, lipid mediators involved in the reduction/resolution of inflammation, in particular, 5-HETE, 11-HETE, and 5-oxoETE, were significantly elevated in mild/moderate disease. Taken together, these immune-biomarker profiles provide insight into immune responses related to COVID-19 pathogenesis. Importantly, our findings suggest that elevation in plasma concentrations of IL-6, CXCL-10, HGF, and anti-SARS-CoV-2 antibodies can predict severe disease, whereas elevation in lipid mediators peaks early (compared to cytokines) and includes induction of mechanisms leading to reduction of inflammation, associated complications, and maintenance of homeostasis.

BackgroundSurgery is accompanied by a systemic inflammatory response that may presage delirium in susceptible individuals. Little is known about the trajectory of plasma proinflammatory cytokines and their potential associations with postoperative delirium (POD). The current study longitudinally assessed both pro and anti-inflammatory plasma cytokine response and development of POD in older surgical patients to investigate associations with individual and/or clusters of cytokines that may indicate pathogenic mechanisms.MethodsA prospective longitudinal study sought to enroll patients >60 years old who were scheduled for major lower limb surgery under general anesthesia. Blood was obtained preoperatively and postoperatively from day 1 through postoperative day 4 for measurement of plasma interleukin-1β (IL-1β), IL-2, IL-4, IL-6, soluble IL-6 receptor (sIL-6R), IL-10, and tumor necrosis factor-α (TNF-α). Participants were assessed for POD twice daily for 4 days using the confusion assessment method. Trajectory of postoperative changes in plasma cytokines was determined by a group-based trajectory modeling analysis that was informed by distinct cytokines identified by time-dependent Cox regression model.ResultsOne hundred eighty-eight patients were assessed for eligibility of whom 129 underwent major surgery and 126 had complete datasets for final analysis. POD was diagnosed in 31 of 126 patients (24.6%). Time-dependent Cox regression model identified that higher IL-6 and sIL-6R levels were associated with higher risk of developing POD. A two-cluster model (stable lower and fluctuating higher levels) was considered to be the most statistically appropriate model for IL-6 and sIL-6R trajectory. More participants with fluctuating higher IL-6 were delirious (73.3% vs 18.0%, P = .001) as were those with fluctuating higher sIL-6R (81.3% vs 16.4%, P = .001).ConclusionsAs higher IL-6 and sIL-6R levels were significantly associated with higher risk of POD and the combination is required for IL-6 trans-signaling, it is possible that activation of this pathway may be associated with POD. Furthermore, it will be important to determine whether high levels of the combination of IL-6 and sIL-6R can be an early biomarker for the subsequent development of POD.

BackgroundInflammatory responses play key roles in the development and progression of many pathological conditions, including neurodegenerative diseases. Accurate quantification of inflammatory factors in saliva would be highly advantageous, given its convenience and non-invasive nature, especially in elderly populations.MethodsIn this study, we measured levels of 10 cytokines, and the pro-inflammatory factor, YKL-40, in plasma and saliva samples from a cohort of nondemented older adults (n = 71; 62% female; 70.3 ± 6.4 years) using sensitive electrochemiluminescence-based immunoassays.ResultsWe found that the mean levels of all cytokines were higher in saliva compared to plasma and that strong sex differences were observed for both saliva and plasma cytokines in this population. Comparing each cytokine between the two biofluids, we found that levels of interferon-gamma (IFNγ), interleukin (IL)-6 and tumor necrosis factor-alpha (TNFα) in blood were significantly correlated with their respective levels in saliva. We further observed that levels of these cytokines in blood were significantly correlated with additional cytokines in saliva, including IL-1β, IL-10, IL-8, IL12p70 and IL-13.ConclusionsThese findings show that inflammatory markers in saliva are associated with those found in circulation, suggesting shared inflammatory mechanisms between these two fluids. The higher levels of cytokines measured in saliva suggest that it might represent a better peripheral fluid to gauge inflammatory processes. Finally, our findings of robust sex differences in several salivary cytokines could have important implications for their potential use as disease biomarkers in the elderly and might be related to sex differences in the prevalence of age-related conditions.

BackgroundHTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is an incapacitating neuroinflammatory disorder for which no disease-modifying therapy is available, but corticosteroids provide some clinical benefit. Although HAM/TSP pathogenesis is not fully elucidated, older age, female sex and higher proviral load are established risk factors. We investigated systemic cytokines and a novel chronic inflammatory marker, GlycA, as possible biomarkers of immunopathogenesis and therapeutic response in HAM/TSP, and examined their interaction with established risk factors.Patients and methodsWe recruited 110 People living with HTLV-1 (PLHTLV-1, 67 asymptomatic individuals and 43 HAM/TSP patients) with a total of 946 person-years of clinical follow-up. Plasma cytokine levels (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-γ, TNF) and GlycA were quantified by Cytometric Bead Array and 1NMR, respectively. Cytokine signaling and prednisolone response were validated in an independent cohort by nCounter digital transcriptomics. We used multivariable regression, machine learning algorithms and Bayesian network learning for biomarker identification.ResultsWe found that systemic IL-6 was positively correlated with both age (r = 0.50, p

BackgroundInterleukin-6 (IL-6), a pleiotropic cytokine with both degenerative and regenerative properties, is necessary and sufficient to provoke perioperative neurocognitive disorders after aseptic trauma in mice. IL-6 initiates its actions after binding to either membrane-bound IL-6 receptor α (mIL-6Rα) through classical signalling, or soluble IL-6 receptor (IL-6R) through trans-signalling; both signalling pathways require the transducer gp130. We investigated the site and type of IL-6 signalling that pertains in a tibial fracture aseptic trauma model of perioperative neurocognitive disorder.MethodsWild-type or genetically altered adult mice that lacked molecules unique to either classical or trans-IL-6 signalling underwent tibial fracture under isoflurane anaesthesia. In separate cohorts, we assessed postoperative memory using a trace fear conditioning paradigm (72 h postoperatively), and post-receptor IL-6 signalling (24 h postoperatively) using phosphorylation of signal transducer and activator of transcription 3 (pSTAT3) in CA1 hippocampal neurones. Fracture healing was assessed at postoperative day 15 after inhibiting either both forms of IL-6 signalling with BE0047 or only trans-signalling with sgp130Fc.ResultsThe surgical phenotype of memory decline (decrease in freezing in trace fear conditioning) and upregulated IL-6 signalling (pSTAT3) did not occur after pretreatment before surgery with either BE0047 or sgp130Fc, or after depleting gp130 from CA1 neurones. The surgical phenotype still occurred when IL-6Rα was depleted in either CA1 hippocampal neurones (freezing time, 38.9% [11.5%] vs 58.4% [12.3%]; pSTAT+ CA1 neurones, 31.7 [4.9] vs 7.0 [3.1]) or microglia (freezing time, 40.1% [13.9%] vs 65.2% [12.6%]; pSTAT+ CA1 neurones, 30.1 [5.5] vs 7.9 [3.2]). In global IL-6Rα-/- mice, hyper-IL-6, the trans-signalling agonist, produced the surgical phenotype when administered i.c.v. (freezing time, 42.4% [8.8%] vs 59.7% [10.4%]; pSTAT+ cells, 29.3 [4.3] vs 10.0 [4.4]). Bone-fracture healing (% of fracture callus comprised of new collagen) was significantly greater with sgp130Fc than with BE0047 (52.2% [8.3%] vs 39.7% [7.9%]).ConclusionsAfter orthopaedic trauma, IL-6 produces perioperative neurocognitive disorders through IL-6 trans-signalling in mouse CA1 neurones. Druggable targets of the trans-signalling pathway should be sought to reduce perioperative neurocognitive disorders while allowing the healing properties of classical IL-6 signalling.

Mechanisms underlying anti-diabetic effects of GLP1 analogs remain incompletely understood. We observed that in prediabetic humans exenatide treatment acutely induces interleukin-6 (IL-6) secretion by monocytes and IL-6 in systemic circulation. We hypothesized that GLP1 analogs signal through IL-6 in adipose tissue (AT) and used the mouse model to test if IL-6 receptor (IL-6R) signaling underlies the effects of the GLP1-IL-6 axis. We show that liraglutide transiently increases IL-6 in mouse circulation and IL-6R signaling in AT. Metronomic liraglutide treatment resulted in AT browning and thermogenesis linked with STAT3 activation. IL-6-blocking antibody treatment inhibited STAT3 activation in AT and suppressed liraglutide-induced increase in thermogenesis and glucose utilization. We show that adipose IL-6R knockout mice still display liraglutide-induced weight loss but lack thermogenic adipocyte browning and metabolism activation. We conclude that the anti-diabetic effects of GLP1 analogs are mediated by transient upregulation of IL-6, which activates canonical IL-6R signaling and thermogenesis.

BackgroundPeople with HIV (PWH) are more likely to experience depression, a highly morbid disease. More evidence is needed to better understand mechanisms of depression in PWH. We evaluated a panel of blood biomarkers in relation to depression symptoms in the Multicenter AIDS Cohort Study (MACS).SettingFour sites in the United States.MethodsA cross-sectional analysis was performed within the MACS, a prospective study of cisgender men with and without HIV. Depression was assessed with the Center for Epidemiological Studies-Depression Scale, and six blood biomarkers were measured: GlycA, high sensitivity C-reactive protein (CRP), interleukin-6, CCL2, soluble CD14 (sCD14), and soluble CD163 (sCD163). Using univariable and multivariable logistic regression, the biomarkers and other factors were evaluated in relation to significant depression symptoms (SDS) by Center for Epidemiological Studies-Depression score ≥16.Results784 men were analyzed; most of whom (63%) were PWH. PWH were more likely to have SDS (32% vs. 21%). In univariable analysis, higher GlycA, CRP, and sCD163 concentrations were associated with SDS. In multivariable analysis, however, only higher sCD163 concentration was associated with SDS (odds ratio = 2.30, 95% CI = 1.11 to 4.76). This relationship was driven by the PWH group (odds ratio = 2.72, 95% CI = 1.12 to 6.58) and remained significant when controlling for antidepressant use. Lack of college education was also associated with SDS.ConclusionsHigher sCD163, a marker of macrophage activation, was significantly associated with significant depression symptoms in the MACS. Further research on this biomarker and macrophage activation in general is warranted to better understand and treat depression in PWH.