Marker Of Macrophage Activation Research Articles

Eicosatetraynoic Acid Regulates Pro-Fibrotic Pathways in an Induced Pluripotent Stem Cell Derived Macrophage:Human Intestinal Organoid Model of Crohn's Disease.

We previously identified small molecules predicted to reverse an ileal gene signature for future Crohn's Disease (CD) strictures. Here we used a new human intestinal organoid (HIO) model system containing macrophages to test a lead candidate, eicosatetraynoic acid (ETYA). Induced pluripotent stem cell lines (iPSC) were derived from CD patients and differentiated into macrophages and HIOs. Macrophages and macrophage:HIO co-cultures were exposed to lipopolysaccharide (LPS) with and without ETYA pre-treatment. Cytospin and flow cytometry characterized macrophage morphology and activation markers, and RNA sequencing defined the global pattern of macrophage gene expression. TaqMan Low Density Array, Luminex multiplex assay, immunohistologic staining, and sirius red polarized light microscopy were performed to measure macrophage cytokine production and HIO pro-fibrotic gene expression and collagen content. iPSC-derived macrophages exhibited morphology similar to primary macrophages and expressed inflammatory macrophage cell surface markers including CD64 and CD68. LPS-stimulated macrophages expressed a global pattern of gene expression enriched in CD ileal inflammatory macrophages and matrisome secreted products, and produced cytokines and chemokines including CCL2, IL1B, and OSM implicated in refractory disease. ETYA suppressed CD64 abundance and pro-fibrotic gene expression pathways in LPS stimulated macrophages. Co-culture of LPS-primed macrophages with HIO led to up-regulation of fibroblast activation genes including ACTA2 and COL1A1, and an increase in HIO collagen content. ETYA pre-treatment prevented pro-fibrotic effects of LPS-primed macrophages. ETYA inhibits pro-fibrotic effects of LPS-primed macrophages upon co-cultured HIO. This model may be used in future untargeted screens for small molecules to treat refractory CD.

Sustained gut dysbiosis and intestinal inflammation show correlation with weight gain in person with chronic HIV infection on antiretroviral therapy

BackgroundPerson with human immunodeficiency virus type-1 (PWH) are prone to chronic inflammation due to residual viral production, even with antiretroviral therapy (ART), which increases the risk of age-related diseases. There is also limited information on changes in the intestinal environment of PWH during ART. In this longitudinal study, we investigated changes in the gut microbiota, persistence of chronic inflammation, interactions between the gut environment and inflammation, and metabolic changes in PWH using long-term ART.ResultsWe analyzed changes in clinical parameters and gut microbiota in 46 PWH over a mean period of 4 years to understand the influence of gut dysbiosis on inflammation. Overall, changes in the gut microbiota included a decrease in some bacteria, mainly involved in short-chain fatty acid (SCFA) production, and an increase in certain opportunistic bacteria. Throughout the study period, an increase in bacterial-specific metabolic activity was observed in the intestinal environment. Continued decline in certain bacteria belonging to the Clostridia class and metabolic changes in gut bacteria involved in glucose metabolism. Additionally, patients with a low abundance of Parabacteroides exhibited low bacterial alpha diversity and a significant increase in body mass index (BMI) during the study period. Monocyte chemoattractant protein 1, a marker of macrophage activation in the plasma, continued to increase from baseline (first stool collection timepoint) to follow-up (second stool collection timepoint), demonstrating a mild correlation with BMI. Elevated BMI was mild to moderately correlated with elevated levels of plasma interleukin 16 and chemokine ligand 13, both of which may play a role in intestinal inflammation and bacterial translocation within the gut microbiota. The rate of BMI increase correlated with the rate of decrease in certain SCFA-producing bacteria, such as Anaerostipes and Coprococcus 3.ConclusionOur data suggest that despite effective ART, PWH with chronic inflammation exhibit persistent dysbiosis associated with gut inflammation, resulting in a transition to an intestinal environment with metabolic consequences. Moreover, the loss of certain bacteria such as Parabacteroides in PWH correlates with weight gain and may contribute to the development of metabolic diseases.

Macrophage activation markers are associated with infection and mortality in patients with acute liver failure.

Acute liver failure is a multisystem disorder with a high mortality and frequent need for emergency liver transplantation. Following massive innate immune system activation, soluble markers of macrophage activation are released during liver damage and their association with disease severity and prognosis requires exploration. Patients ALF from the United States Acute Liver Failure Study Group (USALFSG, n = 224) and King's College Hospital (n = 40) together with healthy controls (HC, n = 50) were recruited. Serum from early (Days 1-3) and late (>Day 3) time points were analysed for MAMs by enzyme-linked immunosorbent assay correlated to markers of illness severity and 21-day spontaneous survival. Surface expression phenotyping was performed via Flow Cytometry on CD14+ monocytes. All MAMs serum concentrations were significantly higher in ALF compared to controls (p < .0001). sCD206 concentration was higher in early and late stages of the disease in patients with bacteraemia (p = .002) and infection in general (p = .006). In MELD-adjusted multivariate modelling, sCD206 and sCD163 were independently associated with mortality. CD14+ monocyte expression of CD206 (p < .001) was higher in patients with ALF compared with controls and correlated with SOFA score (p = .018). sCD206 was independently validated as a predictor of infection in an external cohort. sCD206 is increased in serum of ALF patients with infections and poor outcome and is upregulated on CD14+ monocytes. Later measurements of sCD163 and sCD206 during the evolution of ALF have potential as mechanistic predictors of mortality. sCD206 should be explored as a biomarker of sepsis and mortality in ALF.

Identification of hub genes within the CCL18 signaling pathway in hepatocellular carcinoma through bioinformatics analysis.

Hepatocellular carcinoma (HCC) is an aggressive malignancy, and CCL18, a marker of M2 macrophage activation, is often associated with tumor immune suppression. However, the role of CCL18 and its signaling pathway in HCC is still limited. Our study focuses on investigating the prognostic impact of CCL18 and its signaling pathway in HCC patients and biological functions in vitro. HCC-related RNA-seq data were obtained from TCGA, ICGC, and GEO. The 6 hub genes with the highest correlation to prognosis were identified using univariate Cox and LASSO regression analysis. Multivariate Cox regression analysis was performed to assess their independent prognostic potential and a nomogram was constructed. In vitro experiments, including CCK8, EdU, RT-qPCR, western blot, and transwell assays, were conducted to investigate the biological effects of exogenous CCL18 and 6 hub genes. A core network of highly expressed proteins in the high-risk group of tumors was constructed. Immune cell infiltration was evaluated using the ESTIMATE and CIBERSORT packages. Finally, potential treatments were explored using the OncoPredict package and CAMP database. We identified 6 survival-related genes (BMI1, CCR3, CDC25C, CFL1, LDHA, RAC1) within the CCL18 signaling pathway in HCC patients. A nomogram was constructed using the TCGA_LIHC cohort to predict patient survival probability. Exogenous CCL18, as well as overexpression of BMI1, CCR3, CDC25C, CFL1, LDHA, and RAC1, can promote proliferation, migration, invasion, stemness, and increased expression of PD-L1 protein in LM3 and MHCC-97H cell lines. In the high-risk group of patients from the TCGA_LIHC cohort, immune suppression was observed, with a strong correlation to 21 immune-related genes and suppressive immune cells. Exogenous CCL18 promotes LM3 and MHCC-97H cells proliferation, migration, invasion, stemness, and immune evasion. The high expression of BMI1, CCR3, CDC25C, CFL1, LDHA, and RAC1 can serve as a biomarkers for immune evasion in HCC.

Alleviating 3-MCPD-induced male reproductive toxicity: Mechanistic insights and resveratrol intervention

3-Monochloropropane-1, 2-diol (3-MCPD), a food-borne contaminant, is widely regarded as the primary cause of male infertility. At present, identifying a method to improve/reduce the male reproductive toxicity caused by 3-MCPD is important. In our study, we explored the potential application of resveratrol (RSV) in mitigating the adverse effects of 3-MCPD. Using 7-week-old Sprague-Dawley (SD) rats as animal models, we investigated the impacts and underlying mechanisms of 3-MCPD and RSV on reproductive function. The administration of 3-MCPD led to significant reductions in testicular and epididymal weights, as well as disruptions in spermatogenesis and histological abnormalities. However, co-treatment with RSV and 3-MCPD mitigated these adverse effects. In vitro study, RSV exhibited the ability to reverse the decline in Leydig and Sertoli cell populations inflicted by 3-MCPD treatment. Mechanistically, RSV reduced endoplasmic reticulum stress (PARP), inflammasome activation (NLRP3), and autophagy-mediated lysosome dysfunction (p62 and LC3BII) induced by 3-MCPD. In addition, 3-MCPD treatment increased the expression level of steroidogenesis-related proteins, steroidogenic acute regulatory (StAR) and CYP11A1, but RSV normalized StAR expression. Moreover, 3-MCPD-induced pro-inflammatory responses were counteracted by RSV treatment, with the cytokine reduction and modulation of CD206 expression, a marker of macrophage activation. These findings indicate that RSV attenuates 3-MCPD-induced reproductive toxicity, highlighting its application potential as an adjuvant agent for male reproductive health.

Translocator protein (TSPO) expression in neoplastic cells and tumor-associated macrophages in meningiomas.

Meningiomas are the most common primary intracranial tumors and show extensive infiltration of macrophages. The mitochondrial membrane protein translocator protein (TSPO) has been used as an in vivo marker of microglia and macrophage activation to visualize neuroinflammation. However, it is unknown which cell types express TSPO in meningiomas. Immunohistochemistry of 38 WHO grade 1-3 meningiomas was subjected to segmentation and deep learning classification of TSPO expression to either Iba1-positive tumor-associated macrophages (TAMs) or all other (mainly neoplastic) cells. A possible association between clinical data and TSPO expression intensities was also investigated. TAMs accounted for 15.9%-26% of all cells in the meningioma tissue. Mean fluorescence intensity of TSPO was significantly higher in TAMs (p < 0.0001), but the mass of neoplastic cells in the tumors exceeded that of TAMs. Thus, the summed fluorescence intensity of TSPO in meningioma cells was 64.1% higher than in TAMs (p = 0.0003). We observed no correlation between TSPO expression intensity and WHO grade. These results indicate that both macrophage-lineage and neoplastic cells in meningiomas express TSPO and that the SPECT-TSPO signal in meningiomas mainly reflects the latter; TSPO is expressed equally in parenchymal activated and resting macrophage/microglia lineage cells.

Dynamics of Docosahexaenoic Acid Utilization by Mouse Peritoneal Macrophages.

In this work, the incorporation of docosahexaenoic acid (DHA) in mouse resident peritoneal macrophages and its redistribution within the various phospholipid classes were investigated. Choline glycerophospholipids (PC) behaved as the major initial acceptors of DHA. Prolonged incubation with the fatty acid resulted in the transfer of DHA from PC to ethanolamine glycerophospholipids (PE), reflecting phospholipid remodeling. This process resulted in the cells containing similar amounts of DHA in PC and PE in the resting state. Mass spectrometry-based lipidomic analyses of phospholipid molecular species indicated a marked abundance of DHA in ether phospholipids. Stimulation of the macrophages with yeast-derived zymosan resulted in significant decreases in the levels of all DHA-containing PC and PI species; however, no PE or PS molecular species were found to decrease. In contrast, the levels of an unusual DHA-containing species, namely PI(20:4/22:6), which was barely present in resting cells, were found to markedly increase under zymosan stimulation. The levels of this phospholipid also significantly increased when the calcium-ionophore A23187 or platelet-activating factor were used instead of zymosan to stimulate the macrophages. The study of the route involved in the synthesis of PI(20:4/22:6) suggested that this species is produced through deacylation/reacylation reactions. These results define the increases in PI(20:4/22:6) as a novel lipid metabolic marker of mouse macrophage activation, and provide novel information to understand the regulation of phospholipid fatty acid turnover in activated macrophages.

SAT362 Low-dose DHT’s Effects On Gluconeogenesis And Energy Metabolism Are Ameliorated By Central Nervous System Knockout Of The Androgen Receptor

Abstract Disclosure: V. Ubba: None. S. joseph: None. R. Akbar: None. M. Dsilva: None. S. Wu: None. Polycystic ovarian syndrome (PCOS) is a leading cause of infertility in women of reproductive age. Mostly, the level of androgens are deviated from their physiological values in females, resulting in hyperandrogenemia. Androgen manifests its function in the cells via the Androgen Receptor (AR), making it a prime factor for studying PCOS pathophysiology. We generated central nervous system (CNS) specific AR knockout mouse (SynARKO), using synapsin promoter driven cre, to examine its role under normal and hyperandrogenemic conditions in female mice. Assessment of reproductive parameters under physiological levels of androgens, revealed no differences in the cyclicity and fertility of SynARKO mice when compared to Control (Con-veh) mice. These parameters were altered under hyperandrogenemia (induced using DHT) in Control mice (Con-DHT) mice and were not rescued in the SynARKO- DHT mice, suggesting CNS AR is dispensable to reproductive features in females. Evaluation of metabolic functions by Glucose tolerance test, we observed alleviated glucose intolerance in SynARKO-DHT (4 months). Energy expenditure and food intake were increased in Con-DHT mice compared to Con-veh, while showing no further differences in SynARKO-DHT mice compared to SynARKO-veh. At the molecular level, DHT treatment showed increased phosphorylated Akt in hypothalamus of control mice. Interestingly, it was restored in synARKO upon DHT treatment. Further, the inflammation marker, phosphorylated NF-kB p-65, was increased in the hypothalamus of Con-DHT mice. Additionally, IBA, a marker of macrophage activation was also increased upon DHT treatment in control mice. Taken together, our results suggest that while the reproductive functions are not mediated by the CNS AR, metabolic effects caused by hyperandrogenemia, is regulated by the central nervous system AR. Presentation Date: Saturday, June 17, 2023

Persistent sepsis-induced transcriptomic signatures in signaling pathways of peripheral blood leukocytes: A pilot study

Sepsis is a dysregulated immune response to infections that frequently precipitates multiple organ dysfunction and death despite intensive supportive therapy. The aim of the present study was to identify sepsis-induced alterations in the signaling transcriptome of peripheral blood leukocytes that might shed light on the elusive transition from proinflammatory to anti-inflammatory responses and underlie long-term post-sepsis immunosuppression.Peripheral blood leukocytes were collected from subjects (i) with systemic inflammation, (ii) with sepsis in the acute phase and (iii) 6 months after recovery from sepsis, corresponding to progressive stages of the disease. Transcriptomic analysis was performed with the QuantStudio 12K Flex OpenArray Human Signal Transduction Panel analyzing transcripts of 573 genes playing a significant role in signaling. Of them, 145 genes exhibited differential expression in sepsis as compared to systemic inflammation. Pathway analysis revealed enhanced expression levels of genes involved in primary immune responses (proinflammatory cytokines, neutrophil and macrophage activation markers) and signatures characteristic of immunosuppression (increased expression of anti-inflammatory cytokines and proapoptotic genes; diminished expression of T and B cell receptor dependent activating and survival pathways).Importantly, sepsis-induced expression patterns of 39 genes were not normalized by the end of the 6-month follow-up period, indicating expression aberrations persisting long after clinical recovery. Functional analysis of these transcripts revealed downregulation of the antiapoptotic Wnt and mTOR signaling pathways that might explain the post-sepsis immunosuppression commonly seen in sepsis survivors.

Inflammatory markers and neopterin levels in relation to mild COVID-19.

The immunopathology of acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection involves an excessive inflammatory response. Approximately 80% of patients with coronavirus disease 2019 (COVID-19) have a mild illness, 20% require hospitalization, and approximately 5% require intensive care. Neopterin is a macrophage activation marker produced by monocytes and macrophages following activation by interferon-gamma (IFN-γ). It is crucial to determine neopterin levels and evaluate them together with inflammatory, coagulation, and biochemical markers in moderate/mild SARS-CoV-2 infection. The present study compared plasma neopterin and inflammatory as well as biochemical markers of 50 patients with COVID-19 and 38 healthy volunteers without COVID-19. The data of 38 participants did not show statistically significant differences in serum neopterin levels between the mild/moderate COVID-19 and control groups (p=0.259). White blood cell (WBC), neutrophil, lymphocyte, platelet (PLT), hemoglobin (HGB), procalcitonin (PCT), ferritin, prothrombin time (PT), activated partial thromboplastin time (aPTT), international normalized ratio (INR) and lymphocyte CRP ratio (LCR) values were significantly different between the study groups (p<0.001, p=0.001, p=0.001, p<0.001, p=0.014, p<0.001, p=0.001, p<0.001, p=0.004, p<0.001, p<0.001, respectively). According to the ROC analysis, the WBC, PT, Na, and LCR values exceeding the cutoff values may be predictive of COVID-19. Although there were no significant differences in serum neopterin levels between the groups, there were high values in patients with severe SARS-CoV-2 infection in previous studies and these values were maintained for a long time. The present study found that neopterin levels were not elevated in mild/moderate COVID-19 patients.

SEVERE HEMATOLOGICAL TOXICITY FOLLOWING CD19 CAR‐T FOR RELAPSED/REFRACTORY LBCL IS ASSOCIATED WITH SUPPRESSIVE IMMUNE DYSREGULATION AND LIMITED CAR‐T EXPANSION

Background: Hematological toxicity represents the most frequent high-grade toxicity of CD19 CAR-T, but remains poorly understood. We recently proposed a classification system for CAR-T-related hematotoxicity, defining three unique phenotypes of neutrophil recovery: quick [“Q”] versus intermittent [“I”] versus aplastic [“A”]. Quick: sustained neutrophil recovery without a second dip below an ANC <1000/µL. Intermittent: neutrophil recovery (ANC > 1500/µL) followed by a second dip with an ANC < 1000/µL after day 21. Aplastic: continuous severe neutropenia (ANC < 500/µL) ≥14 days. Multivariable binary logistic regression was applied to analyze clinical metadata. CAR T-cell expansion dynamics were studied during the first 4 months post-CAR-T infusion. The plasma proteome was explored in 58 patients across four time points (day 0, 4, 14, 28) using a 92-protein multiplex proximity extension assay (Olink Bioscience). Progression-free (PFS) and overall survival (OS) were studied via Kaplan-Meier estimates. Results: The distribution of phenotypes was 18%, 42%, and 40% (A vs. I vs. Q). As expected, ‘aplastic’ patients displayed prolonged severe neutropenia (A vs. I vs. Q: 28 vs. 10 vs. 5 days, p < 0.001) and a higher rate of severe infections (40% vs. 22% vs. 18%). On multivariable regression of baseline risk factors (n = 344), the aplastic phenotype was independently associated with the presence of BM infiltration (p = 0.004), low ANC (p = 0.002), and increased ferritin (p = 0.039). When comparing CAR-T expansion among phenotypes, ‘intermittent’ patients displayed the greatest CAR T-cell expansion over time (Figure 1A). Conversely, ‘aplastic’ patients displayed low expansion with an unfavorable relationship between CAR-T expansion and baseline tumor burden (Figure 1B). Serum proteomics revealed higher markers of T-cell suppression, endothelial dysfunction, inflammatory cytokines, and macrophage activation in the ‘aplastic’ phenotype group (Figure 1C). Notably, both PFS and OS was poor in the ’aplastic’patients (1-yr PFS 26%, 1-yr OS 46%). On the other hand, the ‘intermittent’ phenotype, characterized by recurrent neutrophil dips, was associated with superior survival outcomes (1-yr PFS 51%, 1-yr OS 46%). Keywords: aggressive B-cell non-Hodgkin lymphoma, cellular therapies, basic and translational science – Basic and Translational Science - Other Conflicts of interests pertinent to the abstract K. Rejeski Consultant or advisory role: BMS/CELGENE Honoraria: Novartis, BMS/CELGENE Research funding: Kite/Gilead Travel grants: Kite/Gilead

Soluble CD163 is a predictor of fibrosis and hepatocellular carcinoma development in nonalcoholic steatohepatitis

BackgroundNonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. The serum level of soluble CD163 (sCD163), a macrophage activation marker, is associated with liver tissue changes; however, its prognostic value is unknown. Here, we determined the utility of sCD163 as a marker for hepatocellular carcinoma (HCC) and prognostic marker for NAFLD.MethodsThis retrospective study obtained data regarding serum sCD163 levels, liver histology, and background factors associated with NAFLD in 287 patients (men/women, 140/147; average age, 53 ± 14 years) with NAFLD who underwent liver biopsy. Repeated liver biopsies of 287 patients with NAFLD (5.0 ± 2.7 years) were compared regarding serum sCD163 levels and liver tissue changes (stage, grade, steatosis, and NAFLD activity score).ResultsSerum sCD163 levels increased with the progression of liver fibrosis and inflammation (both P < 0.05) and were particularly helpful in distinguishing cases of Grade 4 fibrosis (P < 0.001). Levels of sCD163 significantly decreased in patients with NAFLD exhibiting alleviated fibrosis and inflammation (P < 0.05). We could also predict the development of HCC and associated mortality based on serum sCD163 levels at the time of NAFLD diagnosis. Serum sCD163 levels were higher in patients with HCC than in patients without HCC (1074 ± 379 ng/ml vs. 669 ± 261 ng/ml; P < 0.0001), and the same trend was observed for mortality.ConclusionsThe serum sCD163 level reflects the progression of fibrosis and inflammation in liver tissues, showing much promise as a noninvasive biomarker for nonalcoholic steatohepatitis and NAFLD as well as a possible predictor of HCC development and patient prognosis.

TLR4 is one of the receptors for Chikungunya virus envelope protein E2 and regulates virus induced pro-inflammatory responses in host macrophages.

Toll like receptor 4 (TLR4), a pathogen-associated molecular pattern (PAMP) receptor, is known to exert inflammation in various cases of microbial infection, cancer and autoimmune disorders. However, any such involvement of TLR4 in Chikungunya virus (CHIKV) infection is yet to be explored. Accordingly, the role of TLR4 was investigated towards CHIKV infection and modulation of host immune responses in the current study using mice macrophage cell line RAW264.7, primary macrophage cells of different origins and in vivo mice model. The findings suggest that TLR4 inhibition using TAK-242 (a specific pharmacological inhibitor) reduces viral copy number as well as reduces the CHIKV-E2 protein level significantly using p38 and JNK-MAPK pathways. Moreover, this led to reduced expression of macrophage activation markers like CD14, CD86, MHC-II and pro-inflammatory cytokines (TNF, IL-6, MCP-1) significantly in both the mouse primary macrophages and RAW264.7 cell line, in vitro. Additionally, TAK-242-directed TLR4 inhibition demonstrated a significant reduction of percent E2-positive cells, viral titre and TNF expression in hPBMC-derived macrophages, in vitro. These observations were further validated in TLR4-knockout (KO) RAW cells. Furthermore, the interaction between CHIKV-E2 and TLR4 was demonstrated by immuno-precipitation studies, in vitro and supported by molecular docking analysis, in silico. TLR4-dependent viral entry was further validated by an anti-TLR4 antibody-mediated blocking experiment. It was noticed that TLR4 is necessary for the early events of viral infection, especially during the attachment and entry stages. Interestingly, it was also observed that TLR4 is not involved in the post-entry stages of CHIKV infection in host macrophages. The administration of TAK-242 decreased CHIKV infection significantly by reducing disease manifestations, improving survivability (around 75%) and reducing inflammation in mice model. Collectively, for the first time, this study reports TLR4 as one of the novel receptors to facilitate the attachment and entry of CHIKV in host macrophages, the TLR4-CHIKV-E2 interactions are essential for efficient viral entry and modulation of infection-induced pro-inflammatory responses in host macrophages, which might have translational implication for designing future therapeutics to regulate the CHIKV infection.

The association between soluble CD163, disease severity, and ursodiol treatment in patients with primary biliary cholangitis.

The macrophage activation marker soluble (s)CD163 is associated with disease severity and prognosis in patients with primary biliary cholangitis (PBC). Ursodeoxycholic acid (UDCA) treatment attenuates fibrosis progression in PBC patients, but its effect on macrophage activation is unclear. We examined the effect of UDCA on macrophage activation, as determined by sCD163 levels. We included 2 cohorts of PBC patients; 1 cohort with prevalent PBC patients, and 1 cohort of incident PBC patients before start of UDCA treatment and with follow-up after 4 weeks and 6 months. We measured sCD163 and liver stiffness in both cohorts. Further, we measured sCD163 and TNF-α shedding in vitro in monocyte-derived macrophages after UDCA and lipopolysaccharide incubation. We included 100 patients with prevalent PBC [93% women, median age 63y (interquartile range: 51-70)] and 47 patients with incident PBC [77% women, median age 60y (49-67)]. Prevalent PBC patients had a lower median sCD163 of 3.54mg/L (2.77-4.72) than incident PBC patients with a median sCD163 of 4.33mg/L (2.83-5.99) at inclusion. Patients with an incomplete response to UDCA and patients with cirrhosis had higher sCD163 than responders to UDCA and noncirrhosis patients. After 4 weeks and 6 months of UDCA treatment median sCD163 decreased by 4.6% and 9.0%, respectively. In in vitro experiments, UDCA attenuated shedding of TNF-α, but not sCD163, from monocyte-derived macrophages. In PBC patients, sCD163 levels correlated with liver disease severity and treatment response to UDCA. Further, after 6 months of UDCA treatment, we observed a decrease in sCD163, which may be related to the treatment.

Photobiomodulation activates undifferentiated macrophages and promotes M1/M2 macrophage polarization via PI3K/AKT/mTOR signaling pathway

Macrophages are the main mediators of the inflammatory response and play a major role in the onset and maintenance of periodontitis. Studies revealed that photobiomodulation (PBM) can change the polarization state of macrophages and inflammation reduction, although the cellular mechanisms are not fully elucidated. Here, the present study explored the effect of PBM (980 nm) on undifferentiated and M1-type macrophages and the underlying mechanism. RAW264.7 cells were exposed to laser irradiation under different laser parameters (0.5, 5.0, and 10.0 J/cm2) with or without LY294002 (an inhibitor of PI3K pathway). Then, confocal laser microscopy was used to observe cell differentiation; qPCR was performed to examine the gene expression and western blotting was used to detect the protein in the PI3K/AKT/mTOR pathway and activated macrophage markers. The obtained results revealed that 980 nm PBM increased the mRNA expression of iNOS, Il-10, Arg1, and Il-12 along with the inflammatory cytokines Tnfα, IL-1β, and Il-6 in M0-type macrophages in dose-dependent manner. More interestingly, PBM at 5 J/cm2 decreased the mRNA expression of iNOS, Il-12, Tnfα, IL-1β, and Il-6 and increased the expression of Arg1 and Il-10 by M1-type macrophages, along with the elevated expression of phosphorylation of AKT and mTOR. Moreover, PBM-induced M1-type macrophage polarization was significantly attenuated via LY294002 treatment. These suggest that 980 nm PBM could activate M0-type macrophages and increase M2/M1 ratio via the PI3K/AKT/mTOR pathway.

Hydrogel delivery of purinergic enzymes improves cardiac ischemia/reperfusion injury

RationaleThe innate immune response contributes to cardiac injury in myocardial ischemia/reperfusion (MI/R). Neutrophils are an important early part of the innate immune response to MI/R. Adenosine, an endogenous purine, is a known innate immune modulator and inhibitor of neutrophil activation. However, its delivery to the heart is limited by its short half-life (<30 s) and off-target side effects. CD39 and CD73 are anti-inflammatory homeostatic enzymes that can generate adenosine from phosphorylated adenosine substrate such as ATP released from injured tissue. ObjectiveWe hypothesize that hydrogel-delivered CD39 and CD73 target the local early innate immune response, reduce neutrophil activation, and preserve cardiac function in MI/R injury. Methods and resultsWe engineered a poly(ethylene) glycol (PEG) hydrogel loaded with the adenosine-generating enzymes CD39 and CD73. We incubated the hydrogels with neutrophils in vitro and showed a reduction in hydrogen peroxide production using Amplex Red. We demonstrated availability of substrate for the enzymes in the myocardium in MI/R by LC/MS, and tested release kinetics from the hydrogel. On echocardiography, global longitudinal strain (GLS) was preserved in MI/R hearts treated with the loaded hydrogel. Delivery of purinergic enzymes via this synthetic hydrogel resulted in lower innate immune infiltration into the myocardium post-MI/R, decreased markers of macrophage and neutrophil activation (NETosis), and decreased leukocyte-platelet complexes in circulation. ConclusionsIn a rat model of MI/R injury, CD39 and CD73 delivered via a hydrogel preserve cardiac function by modulating the innate immune response.

EICOSATETRAYNOIC ACID REGULATES PRO-FIBROTIC PATHWAYS IN AN INDUCED PLURIPOTENT STEM CELL DERIVED MACROPHAGE:HUMAN INTESTINAL ORGANOID MODEL OF ILEAL CROHN’S DISEASE

Abstract INTRODUCTION Biologics targeting TNF are the mainstay of therapy for children with Crohn’s Disease (CD). However, a subset of patients do not respond, progressing to intestinal fibrosis requiring surgical resection. Prior studies have defined an ileal gene expression module linked to future strictures, and identified small molecules which may reverse this gene signature and suppress fibroblast activation. In the current study we developed a pre-clinical model system and tested a lead candidate, eicosatetraynoic acid (ETYA), a Peroxisome Proliferator-Activated Receptor (PPAR) agonist and arachidonic acid metabolism inhibitor. METHODS Peripheral blood samples were collected from pediatric CD patients and induced pluripotent stem cell (iPSC) lines were generated. iPSC were differentiated into human intestinal organoids (HIOs) and macrophage-like cells. Macrophage:HIO co-cultures were exposed to lipopolysaccharide (LPS) with and without eicosatetraynoic acid (ETYA) pre-treatment. Flow cytometry and cytospin characterized macrophage activation markers and morphology. Co-culture populations were harvested, and RNA and conditioned media were isolated for downstream analysis. TaqMan Low Density Array, Luminex multiplex assay, immunohistologic staining, and sirius red polarized light microscopy were performed to quantify measures of inflammation and fibrosis, and to test whether introduction of ETYA abated any of these inflammatory or fibrotic changes. RESULTS iPSC-derived macrophages exhibited morphology similar to primary macrophages, and expressed inflammatory macrophage cell surface markers including CD68 (Fig. 1A). LPS-stimulated iPSC-derived macrophages expressed a global pattern of gene expression by RNA sequencing enriched in CD ileal inflammatory macrophages (ToppCell Atlas, p=4.397E-117), and produced cytokines and chemokines implicated in refractory disease (Fig. 1B). Co-culture of LPS-primed macrophages with HIO led to up-regulation of the fibroblast activation genes ACTA2 and COL1A1 (Fig. 2). Under these conditions, HIO collagen content measured by sirius red staining and polarized light microscopy was increased (Fig. 2). ETYA pre-treatment prevented these pro-fibrotic effects of LPS-primed macrophages upon HIO gene expression and collagen content. However, LPS induction of macrophage IL1B, TNF, and OSM production was not suppressed by ETYA, suggesting an alternative mechanism of action upon HIO fibroblast activation and collagen content in the co-culture system. CONCLUSIONS ETYA inhibits effects of LPS-primed macrophages upon HIO pro-fibrotic gene expression and collagen production. This was not associated with an effect of ETYA upon macrophage inflammatory cytokine production. Future studies will test alternate pathways including PPAR activation and arachidonic acid metabolism which may mediate this response.

Lung injury and oxidative stress induced by inhaled chlorine in mice is associated with proinflammatory activation of macrophages and altered bioenergetics

Chlorine (Cl2) gas is a highly toxic and oxidizing irritant that causes life-threatening lung injuries. Herein, we investigated the impact of Cl2-induced injury and oxidative stress on lung macrophage phenotype and function. Spontaneously breathing male C57BL/6J mice were exposed to air or Cl2 (300 ppm, 25 min) in a whole-body exposure chamber. Bronchoalveolar lavage (BAL) fluid and cells, and lung tissue were collected 24 h later and analyzed for markers of injury, oxidative stress and macrophage activation. Exposure of mice to Cl2 resulted in increases in numbers of BAL cells and levels of IgM, total protein, and fibrinogen, indicating alveolar epithelial barrier dysfunction and inflammation. BAL levels of inflammatory proteins including surfactant protein (SP)-D, soluble receptor for glycation end product (sRAGE) and matrix metalloproteinase (MMP)-9 were also increased. Cl2 inhalation resulted in upregulation of phospho-histone H2A.X, a marker of double-strand DNA breaks in the bronchiolar epithelium and alveolar cells; oxidative stress proteins, heme oxygenase (HO)-1 and catalase were also upregulated. Flow cytometric analysis of BAL cells revealed increases in proinflammatory macrophages following Cl2 exposure, whereas numbers of resident and antiinflammatory macrophages were not altered. This was associated with increases in numbers of macrophages expressing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), markers of proinflammatory activation, with no effect on mannose receptor (MR) or Ym-1 expression, markers of antiinflammatory activation. Metabolic analysis of lung cells showed increases in glycolytic activity following Cl2 exposure in line with proinflammatory macrophage activation. Mechanistic understanding of Cl2-induced injury will be useful in the identification of efficacious countermeasures for mitigating morbidity and mortality of this highly toxic gas.

STAT6 suppression prevents bleomycin-induced dermal fibrosis.

Fibrosis of the skin and internal organs is a hallmark of systemic sclerosis (SSc). Although the pathogenesis of SSc is poorly understood, increasing evidence suggests that interleukins (IL)-4 and - 13 contribute to the pathogenesis of skin fibrosis by promoting collagen production and myofibroblast differentiation. Signal transducers and activators of transcription 6 (STAT6) is one of the most important downstream transcription factors activated by both IL-4 and IL-13. However, it is not completely understood whether STAT6 plays a role during the pathogenesis of skin fibrosis in SSc. In this study, we observed increased STAT6 phosphorylation in fibrotic skin samples collected from SSc patients as well as bleomycin-injected murine mice. Knockout of Stat6 in mice significantly (1) suppressed the expression of fibrotic cytokines including Il13, Il17, Il22, Ccl2, and the alternatively activated macrophage marker Cd206; (2) reduced the production of collagen and fibronectin, and (3) attenuated late-stage skin fibrosis and inflammation induced by bleomycin. Consistently, mice treated with STAT6 inhibitor AS1517499 also attenuated skin fibrosis on day 28. In addition, a co-culture experiment demonstrated that skin epithelial cells with STAT6 knockdown had reduced cytokine expression in response to IL-4/IL-13, and subsequently attenuated fibrotic protein expression in skin fibroblasts. On the other side, STAT6 depletion in skin fibroblasts attenuated IL-4/IL-13-induced cytokine and fibrotic marker expression, and reduced CXCL2 expression in co-cultured keratinocytes. In summary, our study highlighted an important yet not fully understood role of STAT6 in skin fibrosis by driving innate inflammation and differentiation of alternatively activated macrophages in response to injury.

Circulating 18-Glycosyl Hydrolase Protein Chitiotriosidase-1 is Associated with Renal Dysfunction and Systemic Inflammation in Diabetic Kidney Disease.

Chitotriosidase-1 (CHIT-1) is a marker of macrophage activation and recently attributed to type 2 diabetes mellitus (T2DM). However, its role in the development and progression of diabetic kidney disease (DKD) has been sparsely discussed in the recent literature. In this cross-sectional exploratory study, 81 participants with T2DM were classified into two groups based on the presence of DKD. Their anthropometric, biochemical, and pathological profiles were estimated. Circulatory CHIT-1 concentration was determined using the enzyme-linked immuno-sorbent assay (ELISA) in plasma. CHIT-1 was significantly elevated in diabetic nephropathy, independent of age and gender. It is associated with severity of kidney disease, as assessed using urinary protein-creatinine ratio (uPCR) in a multiple linear regression model, independent of age, gender, diabetes duration, and insulin resistance. CHIT-1 positively predicted the likelihood of DKD in the study population (area under the curve = 0.724, P < 0.05). The duration of diabetes correlated positively with uPCR and negatively with estimated glomerular-filtration rate. Neutrophil-Lymphocyte ratio was elevated in participants with DKD. This well-established marker of systemic inflammation exhibited significant positive association with CHIT-1. Plasma CHIT-1 protein is elevated in DKD and associated with disease progression. It is capable of reflecting disease severity and is closely related to systemic inflammation possibly caused by pro-inflammatory circulatory immune cells.