Neutrophil-Lymphocyte Ratio and Lymphocyte-Monocyte Ratio correlate with Chronic Prosthetic Joint Infection but are not useful markers for diagnosis.

PURPOSE: To investigate reported correlations between Neutrophil-to-Lymphocyte (NLR) and Lymphocyte-to-Monocyte (LMR) ratios and their value in diagnosis of chronic prosthetic joint infection (PJI) in a large cohort of patients from a single specialist hospital. METHODS: Diagnostic aspirations of 362 patients under investigation for PJI were identified. Of the included patients 185 patients received a final diagnosis of PJI and 177 were classed as aseptic. Established criteria (ICM 2018) were employed to define PJI. Included in the analysis are differential white cell counts, C-Reactive Protein (CRP), Synovial Leukocyte Count, Synovial Alpha-defensin ELISA and Synovial Leukocyte esterase activity. Receiver-operator characteristic (ROC) curves were calculated for each of the available diagnostic tests together with the corresponding area under the curve values (AUC). Youden's index was utilized to identify the optimal diagnostic threshold point for the NLR and LMR. Other diagnostic tests were evaluated as per the threshold values previously defined in the literature and specified in the ICM criteria. RESULTS: Using Youden's Index to identify the optimal NLR cut-off within our cohort we established a value of 2.93. This yielded a sensitivity of 0.60 and specificity of 0.64. The area under the curve (AUC) of a receiving operator characteristics (ROC) curve was 0.625. Regarding the LMR the results demonstrate similar findings; a positive correlation with a diagnosis of infection but poor sensitivity and specificity. The AUC for LMR was 0.633 and was not superior to NLR (P = 0.753). CONCLUSIONS: There is a significant correlation between higher Neutrophil-Lymphocyte and Lymphocyte-Monocyte ratios, and a diagnosis of PJI. The sensitivity and specificity of this calculation is poor and the does not add value to the diagnostic algorithm for PJI. LEVEL OF EVIDENCE: Level III Retrospective Cohort analysis.

Association of C-reactive Protein/Albumin, Procalcitonin/Albumin, Platelet/Lymphocyte, and Lymphocyte/Monocyte Ratio with Mortality in Hospitalised COVID-19 Patients.

OBJECTIVE: To investigate and compare complete blood count and biochemistry parameters such as c-reactive protein/albumin (CRP/ALB) ratio, procalcitonin/albumin (PRO/ALB) ratio, lymphocyte/monocyte (LYM/MON) ratio, platelet/lymphocyte (PLT/LYM) ratio of the recovered/deceased, and ICU (intensive care unit) /ward patients with COVID-19. STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: Department of Internal Medicine, Sakarya University Training and Research Hospital, Turkey, from April 2020 to January 2021. METHODOLOGY: The study was conducted with 590 diagnosed patients with COVID-19. The patients were divided into 2 groups as deceased (n = 294) /survivor (n = 296) and those in need of ICU (n= 418) /ward (n = 172). The information was obtained from the hospital information system and analysed retrospectively. The relationships of crp/alb, pro/alb, lym/mon, and PLT/LYM ratios with patient groups were investigated. RESULTS: Of the total 590 patients in the study, 358 (60.6%) were males. The total mean age was 65.63 ±14.9 years. The mean age of survivor and deceased groups was 71.32±10.9 and 59.97±16.2 years, respectively (p.

Poor performance of monocyte-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, and fibrinogen when screening for occult infection among patients with sequelae of suppurative hip arthritis before total hip arthroplasty.

BACKGROUND: Total hip arthroplasty (THA) is considered the best treatment for sequelae of suppurative hip arthritis, but such patients are more likely to have occult infection and therefore to suffer post-operative periprosthetic joint infection. Our study examined (1) the occult infection rate among patients with sequelae of suppurative hip arthritis, and whether (2) neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), or fibrinogen levels can be used to screen such patients for occult infection before THA. METHODS: We retrospectively enrolled 428 patients who underwent primary THA at our hospital between 2010 and 2021, of whom 31 had occult infection and 397 did not. The maximum sensitivity and specificity were determined for the three indicators using receiver operating characteristic curves, and positive and negative predictive values were calculated. RESULTS: Patients with occult infection showed significantly higher erythrocyte sedimentation rate (ESR) and higher levels of C-reactive protein (CRP) and fibrinogen than those without occult infection. The various potential indicators gave the following areas under the receiver operating characteristic curves: ESR, 0.586; CRP, 0.599; interleukin-6, 0.651; NLR, 0.506; MLR, 0.600; and fibrinogen, 0.589. Sensitivity and specificity were as follows: ESR, 30.8% and 92.5%; CRP, 50.0% and 70.2%; interleukin-6, 57.7% and 67.5%; NLR, 46.7% and 62.9%; MLR, 60.0% and 61.7%; and fibrinogen, 43.3% and 81.7%. CONCLUSION: The rate of occult infection was 7.24% among our patients. ESR, NLR, MLR, and levels of CRP, interleukin-6, and fibrinogen may be unreliable for screening such patients for occult infection before THA according to sensitivity and specificity.

Usefulness of monocyte distribution width (MDW) as a sepsis biomarker.

Sepsis is one of the main causes of mortality in the emergency department (ED), due to the fact that signs and symptoms are common to other acute diseases, and this can result in delayed detection. This diagnostic complexity has a huge impact on an entity in which early recognition determined treatment, as wells as enhance the patient's prognosis. Therefore, it is crucial to improve early identification. Different analytical tools arise from this approach, such as biomarkers: procalcitonin, C-reactive protein or MR-proadrenomedullin. In this review we will focus on a newer biomarker, the monocyte distribution width. The main objectives are to evaluate the usefulness of monocyte distribution width (MDW) in sepsis identification in ED, its limitations, and to compare it with other biomarker.

Usefulness of peripheral blood monocyte count to predict relapse in patients with inflammatory bowel disease: a prospective longitudinal cohort study.

BACKGROUND: monocytes play an important role in the pathogenesis of inflammatory bowel disease but data are scarce regarding activity biomarkers, above all in patients under biologic therapies. OBJECTIVE: the aim of this study was to evaluate the value of monocyte measurements in predicting flares in inflammatory bowel disease patients under maintenance treatment with anti-TNF. METHODS: a prospective, observational cohort study was designed. Relapse was defined as a Harvey-Bradshaw score > 4 in Crohn's disease, and a partial Mayo score ≥ 2 in ulcerative colitis. Monocyte concentration was quantified at 4-month intervals for twelve months. A total of 95 consecutive patients were included. Median age was 42 years, 50.5 % were female, and 75 % had Crohn's disease. RESULTS: sixteen months after inclusion, 65 (68.4 %) patients remained in clinical remission. Mean monocyte count preceding a relapse was 563 (standard deviation: 144) compared to 405 (standard deviation: 177) in patients who remained in remission. Final monocyte count was significantly different between relapse and remission in Crohn's disease (0.82; 95 % CI: 0.71-0.90; p < 0.005). According to the multivariate analysis, only monocytes and fecal calprotectin were related to more relapses. CONCLUSION: in conclusion, in inflammatory bowel disease patients under anti-TNF therapy, repeat monocyte counts could help monitor patients, at least in Crohn's disease.

Differential response of immobile (pneumocytes) and mobile (monocytes) barriers against 2 types of metal oxide nanoparticles.

BACKGROUND: Inhaled nanoparticles (NPs) challenges mobile and immobile barriers in the respiratory tract, which can be represented by type II pneumocytes (immobile) and monocytes (mobile) but what is more important for biological effects, the cell linage, or the type of nanoparticle? Here, we addressed these questions and we demonstrated that the type of NPs exerts a higher influence on biological effects, but cell linages also respond differently against similar type of NPs. DESIGN: Type II pneumocytes and monocytes were exposed to tin dioxide (SnO2) NPs and titanium dioxide (TiO2) NPs (1, 10 and 50 µg/cm2) for 24 h and cell viability, ultrastructure, cell granularity, molecular spectra of lipids, proteins and nucleic acids and cytoskeleton architecture were evaluated. RESULTS: SnO2 NPs and TiO2 NPs are metal oxides with similar physicochemical properties. However, in the absence of cytotoxicity, SnO2 NPs uptake was low in monocytes and higher in type II pneumocytes, while TiO2 NPs were highly internalized by both types of cells. Monocytes exposed to both types of NPs displayed higher number of alterations in the molecular patterns of proteins and nuclei acids analyzed by Fourier-transform infrared spectroscopy (FTIR) than type II pneumocytes. In addition, cells exposed to TiO2 NPs showed more displacements in FTIR spectra of biomolecules than cells exposed to SnO2 NPs. Regarding cell architecture, microtubules were stable in type II pneumocytes exposed to both types of NPs but actin filaments displayed a higher number of alterations in type II pneumocytes and monocytes exposed to SnO2 NPs and TiO2 NPs. NPs exposure induced the formation of large vacuoles only in monocytes, which were not seen in type II pneumocytes. CONCLUSIONS: Most of the cellular effects are influenced by the NPs exposure rather than by the cell type. However, mobile, and immobile barriers in the respiratory tract displayed differential response against SnO2 NPs and TiO2 NPs in absence of cytotoxicity, in which monocytes were more susceptible than type II pneumocytes to NPs exposure.

Inflammation protein quantification by multiple reaction monitoring mass spectrometry in lipopolysaccharide-stimulated THP-1 cells.

RATIONALE: Inflammation is a cascade of events mediated by a cytokine network triggering the cellular response. In order to monitor the modulation of the crucial inflammatory proteins, e.g., Tumour Necrosis Factor-α (TNF-α), Interferon-γ (INF-γ), Interleukin-8 (IL-8) and Interleukin-10 (IL-10), upon stimulation with endotoxins, differentiated and undifferentiated THP-1 cells were treated with lipopolysaccharides (LPSs) from E. coli, key cell wall components of Gram-negative bacteria. METHODS: The multiple reaction monitoring mass spectrometry (MRM-MS) method was optimized by using the standard proteins to be quantified, in order to construct external calibration curves and define the analytical parameters. The developed method was used to quantify the above-mentioned inflammatory proteins in THP-1 differentiated cells upon stimulation with LPSs with high accuracy, sensitivity, and robustness. RESULTS: The analysis of such proteins in MRM mode allowed the kinetics of stimulation along the time up to 24 h to be followed and the MS results were found to be comparable with those obtained by Western-blotting. A significant increase in TNF-α release triggered a cascade mechanism leading to the production of INF-γ and IL-8. IL-10, instead, was found to be constant throughout the process. CONCLUSIONS: The developed MRM-MS method allowed the quantification of TNF-α, INF-γ, IL-8 and IL-10 along a time-course from 2 to 24 h. Hence, a trace of the kinetics of the inflammatory response in THP-1 cells upon stimulation with E. coli LPSs was obtained. Finally, the extensibility of the developed MRM method to serum samples and other matrices demonstrated the versatility of the approach and the possibility to quantify multiple target proteins in different biological samples by using a few microliters in a single analysis.

Can Routine Blood Biochemistry Parameters be Predictive Prognostic Marker(s) in Operated Patients with Meningioma WHO Grade 1?

Background Today, there is a need for new and independent additional advanced markers that can predict the prognosis of meningioma patients, postoperatively. The present study aimed to find out postoperative short-term prognostic markers in patients with meningioma using their demographic data and routine blood biochemistry findings evaluated preoperatively. Methods The Glasgow Coma Scale (GCS), and Glasgow Outcome Scale (GOS) scores of the patients were recorded. Additionally, preoperatively obtained serum glucose, Creactive protein (CRP), sodium, potassium, creatinine, blood urea nitrogen, aspartate aminotransferase (AST), alanine aminotransferase, and hemoglobin level values, platelet, leukocyte, neutrophil, lymphocyte, eosinophil, basophil, andmonocyte count results, erythrocyte sedimentation rate (ESR), neutrophil-lymphocyte ratio, plateletlymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR) values were evaluated. Results In the present study, 23 operated patients with meningioma World Health Organization (WHO) grade 1 (17 females, 6 males) were included. Correlation test results revealed that the GCS score, platelet count, and serum potassium level values could directly predict the short-term prognosis of these patients. Additionally, these test results suggested that the lymphocyte, monocyte, and eosinophil count values, PLR, LMR, ESR, serum glucose, CRP, and AST level values could be indirect markers in predicting the short-term prognosis. However, likelihood ratio test results revealed that only monocyte count value, LMR value, and serum CRP level value could be the markers for prediction of the short-term prognosis. Conclusion At the end of the present study, it was concluded that the monocyte count value, LMR value, and serum CRP level value could be the best markers in predicting the short-term prognosis of the operated meningioma patients.

Monocyte TREM-1 Levels Associate With Anti-TNF Responsiveness in IBD Through Autophagy and Fcγ-Receptor Signaling Pathways.

The expression of Triggering Receptor Expressed on Myeloid cells (TREM)-1 has been described as a predictive marker for anti-Tumor Necrosis Factor (TNF)-α monoclonal antibody (mAb) therapy responsiveness in patients with inflammatory bowel disease (IBD). Here we investigated expression of TREM-1 specifically in CD14+ monocytes in relation to anti-TNF response. The pretreatment TREM-1 expression levels of CD14+ monocytes of Crohn's disease (CD) patients were predictive of outcome to anti-TNF mAb therapy, with low TREM-1 expression associated with response to anti-TNF. FACSorting of CD14+ monocytes with different TREM-1 levels showed that differentiation towards regulatory CD206+ M2 type macrophages by anti-TNF was suppressed in CD14+ monocytes with high TREM-1 expression. Activity of the Fcγ-Receptor and autophagy pathway, both necessary for M2 type differentiation and the response to anti-TNF, were decreased in CD14+ monocytes with high expression of TREM-1. We confirmed that the activity of the Fcγ-Receptor pathway was decreased in the CD patients that did not respond to anti-TNF therapy and that it was negatively correlated with TREM-1 expression levels in the CD patient cohort. In conclusion, our results indicate that TREM-1 expression levels in CD14+ monocytes associate with decreased autophagy and FcγR activity resulting in decreased differentiation to M2 type regulatory macrophages upon anti-TNF mAb treatment, which may explain anti-TNF non-response in IBD patients with high expression levels of TREM-1.

Targeting Immune Cell Metabolism in the Treatment of Inflammatory Bowel Disease.

The cells of the immune system are highly dynamic, constantly sensing and adapting to changes in their surroundings. Complex metabolic pathways govern leukocytes' ability to fine-tune their responses to external threats. Mammalian target of rapamycin complex 1 and hypoxia inducible factor are important hubs of these pathways and play a critical role coordinating cell activation and proliferation and cytokine production. For this reason, these molecules are attractive therapeutic targets in inflammatory disease. Insight into perturbations in immune cell metabolic pathways and their impact on inflammatory bowel disease (IBD) progression are starting to emerge. However, it remains to be determined whether the aberrations in immune metabolism that occur in gut resident immune cells contribute to disease pathogenesis or are reflected in the peripheral blood of patients with IBD. In this review, we explore what is known about the metabolic profile of T cells, monocytes, macrophages, dendritic cells, and natural killer cells in IBD and discuss the potential of manipulating immune cell metabolism as a novel approach to treating IBD.

Elevated Cellular Oxidative Stress in Circulating Immune Cells in Otherwise Healthy Young People Who Use Electronic Cigarettes in a Cross-Sectional Single-Center Study: Implications for Future Cardiovascular Risk.

Background Tobacco cigarettes (TCs) increase oxidative stress and inflammation, both instigators of atherosclerotic cardiac disease. It is unknown if electronic cigarettes (ECs) also increase immune cell oxidative stress. We hypothesized an ordered, "dose-response" relationship, with tobacco-product type as "dose" (lowest in nonsmokers, intermediate in EC vapers, and highest in TC smokers), and the "response" being cellular oxidative stress (COS) in immune cell subtypes, in otherwise, healthy young people. Methods and Results Using flow cytometry and fluorescent probes, COS was determined in immune cell subtypes in 33 otherwise healthy young people: nonsmokers (n=12), EC vapers (n=12), and TC smokers (n=9). Study groups had similar baseline characteristics, including age, sex, race, and education level. A dose-response increase in proinflammatory monocytes and lymphocytes, and their COS content among the 3 study groups was found: lowest in nonsmokers, intermediate in EC vapers, and highest in TC smokers. These findings were most striking in CD14dimCD16+ and CD14++CD16+ proinflammatory monocytes and were reproduced with 2 independent fluorescent probes of COS. Conclusions These findings portend the development of premature cardiovascular disease in otherwise healthy young people who chronically vape ECs. On the other hand, that the COS is lower in EC vapers compared with TC smokers warrants additional investigation to determine if switching to ECs may form part of a harm-reduction strategy. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03823885.

CD14+ CD16+ monocytes are involved in daratumumab-mediated myeloma cells killing and in anti-CD47 therapeutic strategy.

A deep elucidation of the mechanisms of action of anti-CD38 monoclonal antibodies (mAbs), such as daratumumab (DARA), is required to identify patients with multiple myeloma (MM) who are more responsive to this treatment. In the present study, an autologous ex vivo approach was established, focussing on the role of the monocytes in the anti CD38-mediated killing of MM cells. In bone marrow (BM) samples from 29 patients with MM, we found that the ratio between monocytes (CD14+ ) and MM cells (CD138+ ) influences the response to DARA. Further, the exposure of the BM samples to DARA is followed by the formation of a CD138+ CD14+ double-positive (DP) population, that quantitatively correlates with the anti-MM cells killing. These effects were dependent on the presence of a CD14+ CD16+ monocyte subset and on high CD16 expression levels. Lastly, the addition of a mAb neutralising the CD47/signal-regulatory protein α (SIRPα) axis was able to increase the killing mediated by DARA. The effects were observed only in coincidence with high CD14+ :CD138+ ratio, with a significant presence of the DP population and were correlated with CD16 expression. In conclusion, the present study underlines the critical role of the CD16+ monocytes in DARA anti-MM killing effects and gives a rationale to test the combination of an anti-CD47 mAb with anti-CD38 mAbs.

Cross-kingdom mimicry of the receptor signaling and leukocyte recruitment activity of a human cytokine by its plant orthologs.

Human macrophage migration-inhibitory factor (MIF) is an evolutionarily-conserved protein that has both extracellular immune-modulating and intracellular cell-regulatory functions. MIF plays a role in various diseases, including inflammatory diseases, atherosclerosis, autoimmunity, and cancer. It serves as an inflammatory cytokine and chemokine, but also exhibits enzymatic activity. Secreted MIF binds to cell-surface immune receptors such as CD74 and CXCR4. Plants possess MIF orthologs but lack the associated receptors, suggesting functional diversification across kingdoms. Here, we characterized three MIF orthologs (termed MIF/d-dopachrome tautomerase-like proteins or MDLs) of the model plant Arabidopsis thaliana Recombinant Arabidopsis MDLs (AtMDLs) share similar secondary structure characteristics with human MIF, yet only have minimal residual tautomerase activity using either p-hydroxyphenylpyruvate or dopachrome methyl ester as substrate. Site-specific mutagenesis suggests that this is due to a distinct amino acid difference at the catalytic cavity-defining residue Asn-98. Surprisingly, AtMDLs bind to the human MIF receptors CD74 and CXCR4. Moreover, they activate CXCR4-dependent signaling in a receptor-specific yeast reporter system and in CXCR4-expressing human HEK293 transfectants. Notably, plant MDLs exert dose-dependent chemotactic activity toward human monocytes and T cells. A small molecule MIF inhibitor and an allosteric CXCR4 inhibitor counteract this function, revealing its specificity. Our results indicate cross-kingdom conservation of the receptor signaling and leukocyte recruitment capacities of human MIF by its plant orthologs. This may point toward a previously unrecognized interplay between plant proteins and the human innate immune system.

Down-regulation of lincRNA-EPS regulates apoptosis and autophagy in BCG-infected RAW264.7 macrophages via JNK/MAPK signaling pathway.

Macrophages play a major role in the control and elimination of invading Mycobacterium tuberculosis (Mtb). Long intergenic noncoding RNA erythroid prosurvival (lincRNA-EPS) plays an important role in regulating various biologic processes in macrophages, including inflammatory responses, cell apoptosis, and autophagy. Whereas the effect of lincRNA-EPS in regulating the immune response of macrophages to Mtb is little studied. This study aimed to explore lincRNA-EPS expression in monocytes from patients with active pulmonary tuberculosis (PTB) and from healthy individuals. We also sought to investigate the effect of lincRNA-EPS on Bacillus Calmette-Guérin (BCG)-infected macrophages apoptosis and autophagy. Our study found that lincRNA-EPS expression was down-regulated in the monocytes from patients with active PTB compared with healthy individuals, accompanied by significant attenuated monocyte apoptosis and enhanced autophagy. In vitro, knockdown of lincRNA-EPS inhibited apoptosis and promoted autophagy in BCG-infected RAW264.7 macrophages. Moreover, we revealed that lincRNA-EPS regulated apoptosis and autophagy of BCG-infected RAW264.7 macrophages via JNK/MAPK signaling pathway. In conclusion, our findings demonstrated that knockdown of lincRNA-EPS inhibits apoptosis and enhances autophagy by activating the JNK/MAPK signaling pathway in BCG-infected RAW264.7 macrophages. Suggesting that lincRNA-EPS could serve as a new potential therapeutic target for PTB.

Frailty in middle age is associated with frailty status and race-specific changes to the transcriptome.

Frailty is an aging-associated syndrome resulting from diminished capacity to respond to stressors and is a significant risk factor for disability and mortality. Although frailty is usually studied in old age, it is present in mid-life. Given the increases in mortality statistics among middle-aged Americans, understanding molecular drivers of frailty in a younger, diverse cohort may facilitate identifying pathways for early intervention. We analyzed frailty-associated, genome-wide transcriptional changes in middle-aged blacks and whites. Next generation RNA sequencing was completed using total RNA from peripheral blood mononuclear cells (n = 16). We analyzed differential gene expression patterns and completed a parametric analysis of gene set enrichment (PAGE). Differential gene expression was validated using RT-qPCR (n = 52). We identified 5,082 genes differentially expressed with frailty. Frailty altered gene expression patterns and biological pathways differently in blacks and whites, including pathways related to inflammation and immunity. The validation study showed a significant two-way interaction between frailty, race, and expression of the cytokine IL1B and the transcription factor EGR1. The glucose transporter, SLC2A6, the neutrophil receptor, FCGR3B, and the accessory protein, C17orf56, were decreased with frailty. These results suggest that there may be demographic dependent, divergent biological pathways underlying frailty in middle-aged adults.

Mutations found in cell-free DNAs of patients with malignant lymphoma at remission can derive from clonal hematopoiesis.

Cell-free DNA (cfDNA) analysis to detect circulating tumor DNA has been focused on monitoring malignant lymphomas. However, clonal hematopoiesis of indeterminate potential (CHIP)-associated mutations can also be detected by cfDNA analysis. Our aim is to investigate the origin of mutations detected in cfDNA among B-cell lymphoma patients. MYD88/CD79B, DNMT3A, and TP53 were chosen as genes of interest, representing each of the following categories: lymphoma driver genes, CHIP-related genes, and genes shared between lymphoma and CHIP. Seventy-five B-cell lymphoma patients were included in this retrospective study. Serum cfDNAs at time of complete metabolic response (CMR) were sequenced for TP53 (N = 75) and DNMT3A (N = 49). MYD88 p.L265P and CD79B p.Y196C/H mutations were analyzed in diffuse large B-cell lymphoma (DLBCL) patients whose tumor samples were available (N = 29). Two and seven mutations in TP53 and DNMT3A, respectively, were detected in cfDNA at CMR. These mutations were detected in either bone marrow mononuclear cells (BMMC) or PBMC. Although four DNMT3A mutations were also detected in tumors, median variant allele frequencies in the tumors (<1.0%) were significantly lower than those in both BMMC (6.1%) and serum (5.2%) obtained before the therapy. Conversely, five MYD88 and three CD79B mutations detected in tumors were confirmed in cfDNA before therapy, but not in BMMC nor in cfDNA at CMR. Thus, all TP53 and DNMT3A mutations detected in cfDNA at remission seemed to originate from CHIP rather than from residual disease. Results of liquid biopsy should be carefully interpreted, especially in genes shared between lymphomas and CHIP.

Comparative DNA methylomic analyses reveal potential origins of novel epigenetic biomarkers of insulin resistance in monocytes from virally suppressed HIV-infected adults.

BACKGROUND: Compared to healthy individuals, those with stably repressed HIV experience a higher risk of developing insulin resistance, a hallmark of pre-diabetes and a major determinant for cardiometabolic diseases. Although epigenetic processes, including in particular DNA methylation, appear to be dysregulated in individuals with insulin resistance, little is known about where these occur in the genomes of immune cells and the origins of these alterations in HIV-infected individuals. Here, we examined the genome-wide DNA methylation states of monocytes in HIV-infected individuals (n = 37) with varying levels of insulin sensitivity measured by the homeostatic model assessment of insulin resistance (HOMA-IR). RESULTS: By profiling DNA methylation at single-nucleotide resolution using the Illumina Infinium HumanMethylation450 BeadChip in monocytes from insulin-resistant (IR; HOMA-IR ≥ 2.0; n = 14) and insulin-sensitive (IS; HOMA-IR < 2.0; n = 23) individuals, we identified 123 CpGs with significantly different DNA methylation levels. These CpGs were enriched at genes involved in pathways relating to glucose metabolism, immune activation, and insulin-relevant signaling, with the majority (86.2%) being hypomethylated in IR relative to IS individuals. Using a stepwise multiple logistic regression analysis, we observed 4 CpGs (cg27655935, cg02000426, cg10184328, and cg23085143) whose methylation levels independently predicted the insulin-resistant state at a higher confidence than that of clinical risk factors typically associated with insulin resistance (i.e., fasting glucose, 120-min oral glucose tolerance test, Framingham Risk Score, and Total to HDL cholesterol ratio). Interestingly, 79 of the 123 CpGs (64%) exhibited remarkably similar levels of methylation as that of hematopoietic stem cells (HSC) in monocytes from IR individuals, implicating epigenetic defects in myeloid differentiation as a possible origin for the methylation landscape underlying the insulin resistance phenotype. In support of this, gene ontology analysis of these 79 CpGs revealed overrepresentation of these CpGs at genes relevant to HSC function, including involvement in stem cell pluripotency, differentiation, and Wnt signaling pathways. CONCLUSION: Altogether, our data suggests a possible role for DNA methylation in regulating monocyte activity that may associate with the insulin-resistant phenotype. The methylomic landscape of insulin resistance in monocytes could originate from epigenetic dysregulation during HSC differentiation through the myeloid lineage. Understanding the factors involved with changes in the myeloid trajectory may provide further insight into the development of insulin resistance. Furthermore, regulation of specific genes that were implicated in our analysis reveal possible targets for modulating immune activity to ameliorate insulin resistance.

Surface-Engineered Monocyte Inhibits Atherosclerotic Plaque Destabilization via Graphene Quantum Dot-Mediated MicroRNA Delivery.

Rupture-prone atherosclerotic plaque is the cause of the high mortality and morbidity rates that accompany atherosclerosis-associated diseases. MicroRNAs can regulate the expression of a variety of atherosclerotic inflammation-related genes in macrophages. There are currently no definitive methods for delivering microRNAs into the interior of plaque. Monocytes typically possess a pathological feature that allows them to be recruited to atherosclerotic plaque resulting in rupture-prone; however, whether monocytes can be modified to be gene carriers remains unclear. In this study, a novel monocyte surface-engineered gene-delivery system based on graphene quantum dots (GQDs) is developed. Briefly, GQDs-microRNA223 linked by disulfide bonds are grafted onto the monocyte membrane via a carefully designed C18-peptide (C18P) containing a hydrophobic end to afford the designed monocyte-C18P-GQDs-miR223 architecture. The system can reach and enter the interior of the plaque and release the GQDs-miRNA via C18P digestion. The released GQDs-miRNA are taken up by the macrophages in atherosclerotic plaques, and the disulfide linkages between the GQDs and the miRNA are cleaved through γ-interferon-inducible lysosomal thiol reductase (GILT) in the lysosome. Under the protection of GQDs, miRNA cargos are transfected into the cytosol and subsequently undergo nuclear translocation, allowing a significantly reduced plaque burden by regulating inflammatory response in vivo.

Efficient integration of heterogeneous single-cell transcriptomes using Scanorama.

Integration of single-cell RNA sequencing (scRNA-seq) data from multiple experiments, laboratories and technologies can uncover biological insights, but current methods for scRNA-seq data integration are limited by a requirement for datasets to derive from functionally similar cells. We present Scanorama, an algorithm that identifies and merges the shared cell types among all pairs of datasets and accurately integrates heterogeneous collections of scRNA-seq data. We applied Scanorama to integrate and remove batch effects across 105,476 cells from 26 diverse scRNA-seq experiments representing 9 different technologies. Scanorama is sensitive to subtle temporal changes within the same cell lineage, successfully integrating functionally similar cells across time series data of CD14+ monocytes at different stages of differentiation into macrophages. Finally, we show that Scanorama is orders of magnitude faster than existing techniques and can integrate a collection of 1,095,538 cells in just ~9 h.