Perspectives for Monocyte/Macrophage-Based Diagnostics of Chronic Inflammation

Partial recovery of peripheral blood monocyte subsets in head and neck squamous cell carcinoma patients upon radio(chemo)therapy is associated with decreased plasma CXCL11

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) represents a common and heterogeneous malignancy of the oral cavity, pharynx and larynx. Surgery and radio(chemo)therapy are the standard treatment options and also have great influence on the composition of the tumor microenvironment and immune cell functions. However, the impact of radio(chemo)therapy on the distribution and characteristics of circulating monocyte subsets in HNSCC are not fully understood.

METHODS

Expression patterns of adhesion molecules and chemokine receptors CD11a (integrin-α L; LFA-1), CD11b (integrin-α M; Mac-1), CD11c (integrin-α X), CX3CR1 (CX3CL1 receptor) and checkpoint molecule PD-L1 (programmed cell death ligand-1) were investigated upon radio(chemo)therapeutic treatment using flow cytometry. Furthermore, comprehensive analysis of plasma cytokines was performed before and after treatment using ELISA measurements.

RESULTS

Our data reveal a partial recovery of circulating monocytes in HNSCC patients upon radio(chemo)therapeutic treatment, with differential effects of the individual therapy regimen. PD-L1 expression on non-classical monocytes significantly correlates with the individual plasma levels of chemokine CXCL11 (C-X-C motif chemokine 11).

CONCLUSIONS

Further comprehensive investigations on larger patient cohorts are required to elucidate the meaningfulness of peripheral blood monocyte subsets and chemokine CXCL11 as potential bioliquid indicators in HNSCC with regard to therapy response and the individual immunological situation.

Specific changes in amino acid profiles in monocytes of patients with breast, lung, colorectal and ovarian cancers

Introduction

Immunometabolism is essential factor of tumor progression, and tumor-associated macrophages are characterized by substantial changes in their metabolic status. In this study for the first time, we applied targeted amino acid LC-MS/MS analysis to compare amino acid metabolism of circulating monocytes isolated from patients with breast, ovarian, lung, and colorectal cancer.

Methods

Monocyte metabolomics was analyzed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/ MS) analysis of amino acid extracts. The targeted analysis of 26 amino acids was conducted by LCMS/MS on an Agilent 6460 triple quadrupole mass spectrometer equipped with an electrospray ionization source and an Agilent 1260 II liquid chromatograph.

Results

Comparison of monocytes of cancer patients with monocytes of healthy control individuals demonstrated that in breast cancer most pronounced changes were identified for tryptophan (AUC = 0.76); for ovarian cancer, aminobutyric acid was significantly elevated (AUC= 1.00); for lung cancer significant changes we indented for citrulline (AUC = 0.70). In order to identify key amino acids that are characteristic for monocytes in specific cancer types, we compared each individual cancer with other 3 types of cancer. We found, that aspartic acid and citrulline are specific for monocytes of patients with colorectal cancer (p<0.001, FC = 1.40 and p=0.003, FC = 1.42 respectively). Citrulline, sarcosine and glutamic acid are ovarian cancer-specific amino acids (p = 0.003, FC = 0.78, p = 0.003, FC = 0.62, p = 0.02, FC = 0.78 respectively). Glutamine, methionine and phenylalanine (p = 0.048, FC = 1.39. p = 0.03, FC = 1.27 and p = 0.02, FC = 1.41) are lung cancer-specific amino acids. Ornithine in monocytes demonstrated strong positive correlation (r = 0.63) with lymph node metastasis incidence in breast cancer patients. Methyl histidine and cysteine in monocytes had strong negative correlation with lymph node metastasis in ovarian cancer patients (r = -0.95 and r = -0.95 respectively). Arginine, citrulline and ornithine have strong negative correlation with tumor size (r = -0.78, citrulline) and lymph node metastasis (r = -0.63 for arginine and r = -0.66 for ornithine).

Discussion

These alterations in monocyte amino acid metabolism can reflect the reaction of systemic innate immunity on the growing tumor. Our data indicate that this metabolic programming is cancer specific and can be inhibiting cancer progression. Cancer-specific differences in citrulline, as molecular link between metabolic pathways and epigenetic programing, provide new option for the development and validation of anti-cancer therapies using inhibitors of enzymes catalyzing citrullination.

Interaction of Ceramic Implant Materials with Immune System

The immuno-compatibility of implant materials is a key issue for both initial and long-term implant integration. Ceramic implants have several advantages that make them highly promising for long-term medical solutions. These beneficial characteristics include such things as the material availability, possibility to manufacture various shapes and surface structures, osteo-inductivity and osteo-conductivity, low level of corrosion and general biocompatibility. The immuno-compatibility of an implant essentially depends on the interaction with local resident immune cells and, first of all, macrophages. However, in the case of ceramics, these interactions are insufficiently understood and require intensive experimental examinations. Our review summarizes the state of the art in variants of ceramic implants: mechanical properties, different chemical modifications of the basic material, surface structures and modifications, implant shapes and porosity. We collected the available information about the interaction of ceramics with the immune system and highlighted the studies that reported ceramic-specific local or systemic effects on the immune system. We disclosed the gaps in knowledge and outlined the perspectives for the identification to ceramic-specific interactions with the immune system using advanced quantitative technologies. We discussed the approaches for ceramic implant modification and pointed out the need for data integration using mathematic modelling of the multiple ceramic implant characteristics and their contribution for long-term implant bio- and immuno-compatibility.

PFKFB3 overexpression in monocytes of patients with colon but not rectal cancer programs pro-tumor macrophages and is indicative for higher risk of tumor relapse

Introduction

Circulating monocytes are main source for tumor-associated macrophages (TAMs) that control tumor growth, angiogenesis, metastasis and therapy resistance. We raised the questions how monocyte programming is affected by growing tumors localized in colon and rectal sections, and how treatment onsets affect monocyte programming in the circulation.

Methods

Patients with rectal cancer and colon cancer were enrolled in the study. Peripheral blood monocytes were characterized by phenotypic analysis using flow cytometry, by transcriptomic analysis using RNA sequencing and by gene expression analysis using real-time RT-PCR. Phenotypic analysis was performed with IF/confocal microscopy. Spatial transcriptomic analysis was applied using GeoMX DSP-NGS.

Results

In patients with rectal cancer, increased amount of CCR2+ monocytes was indicative for the absence of both lymphatic and hematogenous metastasis. In contrast, in patients with colon cancer CD163+ monocytes were indicative for LN metastasis. NGS analysis identified tumor-specific transcriptional programming of monocytes in all CRC patients compared to healthy individuals. The key transcriptional difference between monocytes of patients with colon and rectal cancer was increased expression of PFKFB3, activator of glycolysis that is currently considered as therapy target for major solid cancers. PFKFB3-expressing monocyte-derived macrophages massively infiltrated tumor in colon. Nanostring technology identified correlation of PFKFB3 with amount and tumor-promoting properties of TAMs in colon but not in rectal cancer. PFKFB3 was indicative for tumor relapse specifically in colon cancer.

Discussion

Our findings provide essential argument towards CRC definition to cover two clinically distinct cancers - colon cancer and rectal cancer, that differentially interact with innate immunity.

Peculiarities of amino acid profile in monocytes in breast cancer

Monocytes are large circulating white blood cells that are the main precursors of tissue macrophages as well as tumor-associated macrophages in the adult body. Different types of monocytes have multidirectional effects on the growth and metastatic spread of cancer cells, both activating and inhibiting these processes. Tumor progression is associated with the triggering of a whole cascade of inflammatory and immune reactions. These pathological processes are associated with changes in the amino acid content of monocytes, which can lead to disruption of their function, in particular their migration, division and maturation. The aim of the work was to profile the amino acids of monocytes, followed by a study of the amino acid composition of monocytes from patients with breast cancer using liquid chromatography with mass spectrometric detection. Significant differences in metabolite levels in monocytes of breast cancer patients and monocytes of healthy donors were found for glycine (p-value = 0.0127), asparagine (p-value = 0.0197), proline (p-value = 0.0159), methionine (p-value = 0.0357), tryptophan (p-value = 0.0028), tyrosine (p-value = 0.0127). In the study, we identified biological networks that could potentially be involved in altering the phenotype of monocytes affected by breast cancer (BC), using bioinformatic analysis of metabolic pathways involving the discovered amino acids. Mathematical models based on amino acid combinations with 100% sensitivity and specificity have been developed. Features of immune system cell metabolism in BC have been identified and potential diagnostic biomarkers have been proposed.

Intermediate monocytes expansion and homing markers expression in COVID-19 patients associate with kidney dysfunction

Patients with severe SARS-CoV-2 infection have an overwhelming inflammatory response characterized by remarkable organs monocyte infiltration. We performed an immunophenotypic analysis on circulating monocytes in 19 COVID-19 patients in comparison with 11 naïve HIV-1 patients and 10 healthy subjects. Reduced frequency of classical monocytes and increased frequency of intermediate monocytes characterized COVID-19 patients with respect to both HIV naïve patients and healthy subjects. Intensity of C-C motif chemokine receptor 2 (CCR2) monocyte expression highly correlated with parameters of kidney dysfunction. Our data indicate that highly activated monocytes of COVID-19 patients may be pathogenically associated with the development of renal disease.

Monocyte programming by cancer therapy

Monocytes in peripheral blood circulation are the precursor of essential cells that control tumor progression, that include tumor-associated macrophages (TAMs), dendritic cells (DCs) and myeloid-derive suppressor cells (MDSC). Monocytes-derived cells orchestrate immune reactions in tumor microenvironment that control disease outcome and efficiency of cancer therapy. Four major types of anti-cancer therapy, surgery, radiotherapy, chemotherapy, and most recent immunotherapy, affect tumor-associated macrophage (TAM) polarization and functions. TAMs can also decrease the efficiency of therapy in a tumor-specific way. Monocytes is a major source of TAMs, and are recruited to tumor mass from the blood circulation. However, the mechanisms of monocyte programming in circulation by different therapeutic onsets are only emerging. In our review, we present the state-of-the art about the effects of anti-cancer therapy on monocyte progenitors and their dedifferentiation, on the content of monocyte subpopulations and their transcriptional programs in the circulation, on their recruitment into tumor mass and their potential to give origin for TAMs in tumor-specific microenvironment. We have also summarized very limited available knowledge about genetics that can affect monocyte interaction with cancer therapy, and highlighted the perspectives for the therapeutic targeting of circulating monocytes in cancer patients. We summarized the knowledge about the mediators that affect monocytes fate in all four types of therapies, and we highlighted the perspectives for targeting monocytes to develop combined and minimally invasive anti-cancer therapeutic approaches.

Effect of Early-Stage Human Breast Carcinoma on Monocyte Programming

Circulating monocytes are a major source of tumor-associated macrophages (TAMs). TAMs in human breast cancer (BC) support primary tumor growth and metastasis. Neoadjuvant chemotherapy (NAC) is a commonly used treatment for BC patients. The absence of the response to NAC has major negative consequences for the patient: increase of tumor mass, delayed surgery, and unnecessary toxicity. We aimed to identify the effect of BC on the subpopulation content and transcriptome of circulating monocytes. We examined how monocyte phenotypes correlate with the response to NAC. The percentage of CD14-, CD16-, CD163-, and HLA-DR-expressing monocytes was quantified by flow cytometry for patients with T1-4N0-3M0 before NAC. The clinical efficacy of NAC was assessed by RECIST criteria of RECIST 1.1 and by the pathological complete response (pCR). The percentage of CD14+ and СD16+ monocytes did not differ between healthy women and BC patients and did not differ between NAC responders and non-responders. The percentage of CD163-expressing CD14^lowCD16+ and CD14+CD16+ monocytes was increased in BC patients compared to healthy women (99.08% vs. 60.00%, p = 0.039, and 98.08% vs. 86.96%, p = 0.046, respectively). Quantitative immunohistology and confocal microscopy demonstrated that increased levels of CD163+ monocytes are recruited in the tumor after NAC. The percentage of CD14^lowCD16+ in the total monocyte population positively correlated with the response to NAC assessed by pCR: 8.3% patients with pCR versus 2.5% without pCR (p = 0.018). Search for the specific monocyte surface markers correlating with NAC response evaluated by RECIST 1.1 revealed that patients with no response to NAC had a significantly lower amount of CD14^lowCD16+HLA-DR+ cells compared to the patients with clinical response to NAC (55.12% vs. 84.62%, p = 0.005). NGS identified significant changes in the whole transcriptome of monocytes of BC patients. Regulators of inflammation and monocyte migration were upregulated, and genes responsible for the chromatin remodeling were suppressed in monocyte BC patients. In summary, our study demonstrated that presence of BC before distant metastasis is detectable, significantly effects on both monocyte phenotype and transcriptome. The most striking surface markers were CD163 for the presence of BC, and HLA-DR (CD14^lowCD16+HLA-DR+) for the response to NAC.

Modulation of the inflammatory response to decellularized collagen matrix for cartilage regeneration

Decellularized extracellular matrices (DECM) are among the most common types of materials used in tissue engineering due to their cell instructive properties, biodegradability, and accessibility. Particularly in cartilage, a natural collagen type II matrix can be a promising means to provide the necessary cues and support for chondrogenic stem and progenitor cells (CSPCs). However, efficient remodeling of the transplanted DECM is largely dependent on the host immune response, with macrophages playing the central role in orchestrating both inflammatory and regenerative processes. Here we assessed the reaction of human primary macrophages to the cartilage DECM. Our findings show that the xenogeneic collagen matrix can elicit a mixed response in human macrophages, whereby the inflammatory response (M1) and the activation of remodeling (M2) type of macrophages are both present. Additionally, we demonstrate the inhibitory effect of macrophage response on the migratory capacity of human CSPCs. We further show that the inflammatory reaction of macrophages to the cartilage DECM, as well as the resulting inhibitory effects on CSPC migration, can be attenuated by interleukin-4 (IL-4). Finally, we demonstrate that IL-4 can effectively bind the matrix, thereby modulating macrophage response by reducing the inflammatory reaction and inducing the M2 phenotype.

Predictive potential of macrophage population phenotyping in malignization of H. pylori-associated chronic gastritis

Tumor-associated macrophages are able to regulate the tumor cell proliferation and to affect the tumor cell dissemination. The study was aimed to assess the predictive potential of the macrophage population immunohistochemical phenotyping in early malignization of H. pylori-associated chronic gastritis. Gastic biopsy samples of male and female patients aged 48 ± 7.2 infected with Helicobacter pylori were used as the research material. The patients were divided into three groups: non-atrophic chronic gastritis (NACG, n = 10), atrophic chronic gastritis (ACG, n = 10), G1/G2 gastric adenocarcinoma (GAC, n = 10). The macrophage population was visualized using the CD68 pan-macrophage marker and the type 2 monocyte/macrophage marker CD163. Intensity of neoangiogenesis was defined using the CD31 endothelial marker by assessing the total cross sectional area of blood vessels. It was found that chronic gastritis was accompanied by the dynamic increase in the size of the general macrophage population with the progression of atrophic and metaplastic processes. According to immunohistochemical study of biopsies obtained from patients with NCG, the CD163 : CD68 ratio was 0.67 ± 0.02, and the total cross sectional area of blood vessels was 3590.92 ± 356.27 µm2. Atrophic gastritis and adenocarcinoma were characterized by vector redistribution of monocytes/macrophages into the 2nd functional phenotype. The CD163 : CD68 expression index in the group with ACG was 0.81 ± 0.04, and in the group with GAC it was 0.88 ± 0.03. Microvascular area was significantly increased in the groups with ACG and GAC, which reflected tumor neoangiogenesis intensification under the influence of М2 monocytes/macrophages. The increased expression of CD163 can serve as a predictor of chronic gastritis malignization together with evaluation of the glandular epithelium atrophy and metaplasia degree.

Elevated Plasma Fractalkine Level Is Associated with the Severity of Hemorrhagic Fever with Renal Syndrome in Humans

Hantaan virus infection may cause severe lethal hemorrhagic fever with renal syndrome (HFRS) in humans. The chemokine fractalkine (CX3CL1) acts as a proinflammatory cytokine, and it is elevated in several infectious diseases. However, little is known about the contributions of CX3CL1 to HFRS pathogenesis. Present study detected plasma CX3CL1 levels and expression of the receptor CX3CR1 in HFRS patients and discussed the possible effects of CX3CL1 on pathogenesis of HFRS. Plasma CX3CL1 in acute phase and Critical/Severe groups of HFRS patients were significantly increased compared to that in normal controls (p < 0.001 and p < 0.01, respectively). High plasma CX3CL1 was negatively correlated with platelet count (r = -0.5844, p < 0.0001) and positively correlated with blood urea nitrogen (r = 0.3668, p = 0.0039), creatinine (r = 0.42, p = 0.0008), and white blood cells (r = 0.2646, p = 0.0411). Expression of CX3CR1 on nonclassical and intermediate monocytes was also increased in the acute phase (p < 0.01 for both the cells) and Critical/Severe groups (p < 0.05 and p < 0.01, respectively) of HFRS patients compared to that in normal controls. Taken together, elevation of plasma CX3CL1 in HFRS patients and expression of CX3CR1 on nonclassical and intermediate monocyte subsets might provide new insights into the potential role of CX3CL1/CX3CR1 in pathogenesis of HFRS.

Immunophenotype-associated gene signature in ductal breast tumors varies by receptor subtype, but the expression of individual signature genes remains consistent

BACKGROUND

In silico deconvolution of invasive immune cell infiltration in bulk breast tumors helps characterize immunophenotype, expands treatment options, and influences survival endpoints. In this study, we identify the differential expression (DE) of the LM22 signature to classify immune-rich and -poor breast tumors and evaluate immune infiltration by receptor subtype and lymph node metastasis.

METHODS

Using publicly available data, we applied the CIBERSORT algorithm to estimate immune cells infiltrating the tumor into immune-rich and immune-poor groups. We then tested the association of receptor subtype and nodal status with immune-rich/poor phenotype. We used DE to test individual signature genes and over-representation analysis for related pathways.

RESULTS

CCL19 and CXCL9 expression differed between rich/poor signature groups regardless of subtype. Overexpression of CHI3L2 and FES was observed in triple negative breast cancers (TNBCs) relative to other subtypes in immune-rich tumors. Non-signature genes, LYZ, C1QB, CORO1A, EVI2B, GBP1, PSMB9, and CD52 were consistently overexpressed in immune-rich tumors, and SCUBE2 and GRIA2 were associated with immune-poor tumors. Immune-rich tumors had significant upregulation of genes/pathways while none were identified in immune-poor tumors.

CONCLUSIONS

Overall, the proportion of immune-rich/poor tumors differed by subtype; however, a subset of 10 LM22 genes that marked immune-rich status remained the same across subtype. Non-LM22 genes differentially expressed between the phenotypes suggest that the biologic processes responsible for immune-poor phenotype are not yet well characterized.

Pathogenesis of Coronaviruses Through Human Monocytes and Tissue Macrophages

Coronaviruses (CoVs) contribute significantly to the burden of respiratory diseases, frequently as upper respiratory tract infections. Recent emergence of novel coronaviruses in the last few decades has highlighted the potential transmission, disease, and mortality related to these viruses. In this literature review, we shall explore the disease-causing mechanism of the virus through human monocytes and macrophages. Common strains will be discussed; however, this review will center around coronaviruses responsible for epidemics, namely severe acute respiratory syndrome coronavirus (SARS-CoV)-1 and -2 and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Macrophages are key players in the immune system and have been found to play a role in the pathogenesis of lethal coronaviruses. In physiology, they are white blood cells that engulf and digest cellular debris, foreign substances, and microbes. They play a critical role in innate immunity and help initiate adaptive immunity. Human coronaviruses utilize various mechanisms to undermine the innate immune response through its interaction with macrophages and monocytes. It is capable of entering immune cells through DPP4 (dipeptidyl-peptidase 4) receptors and antibody-dependent enhancement, delaying initial interferon response which supports robust viral replication. Pathogenesis includes triggering the production of overwhelming pro-inflammatory cytokines that attract other immune cells to the site of infection, which propagate prolonged pro-inflammatory response. The virus has also been found to suppress the release of anti-inflammatory mediators such as IL-10, leading to an aberrant inflammatory response. Elevated serum cytokines are also believed to contribute to pathological features seen in severe disease such as coagulopathy, acute lung injury, and multiorgan failure.

Time-Resolved and Comprehensive Analysis of Surface Glycoproteins Reveals Distinct Responses of Monocytes and Macrophages to Bacterial Infection

Glycoproteins on the surface of immune cells play extremely important roles in response to pathogens. Yet, a systematic and time-resolved investigation of surface glycoproteins during the immune response remains to be explored. Integrating selective enrichment of surface glycoproteins with multiplexed proteomics, we globally and site-specifically quantified the dynamics of surface glycoproteins on THP-1 monocytes and macrophages in response to bacterial infection and during the monocyte-to-macrophage differentiation. The time-resolved analysis reveals transient changes and differential remodeling of surface glycoproteins on both cell types, and potential upstream regulators and downstream effects of the regulated glycoproteins. Besides, we identified novel surface glycoproteins participating in the immune response such as APMAP, and site-specific changes of glycoproteins. This study provides unprecedented information to deepen our understanding of glycoproteins and cellular activities.

Time-Resolved and Comprehensive Analysis of Surface Glycoproteins Reveals Distinct Responses of Monocytes and Macrophages to Bacterial Infection

Glycoproteins on the surface of immune cells play extremely important roles in response to pathogens. Yet, a systematic and time-resolved investigation of surface glycoproteins during the immune response remains to be explored. Integrating selective enrichment of surface glycoproteins with multiplexed proteomics, we globally and site-specifically quantified the dynamics of surface glycoproteins on THP-1 monocytes and macrophages in response to bacterial infection and during the monocyte-to-macrophage differentiation. The time-resolved analysis reveals transient changes and differential remodeling of surface glycoproteins on both cell types, and potential upstream regulators and downstream effects of the regulated glycoproteins. Besides, we identified novel surface glycoproteins participating in the immune response such as APMAP, and site-specific changes of glycoproteins. This study provides unprecedented information to deepen our understanding of glycoproteins and cellular activities.

The Monocyte to High-Density Lipoprotein Cholesterol Ratio in the Prediction for Atherosclerosis: A Retrospective Study in Adult Chinese Participants

The ratio of monocyte to high-density lipoprotein cholesterol level (MHR) was a newly proposed inflammatory and oxidative stress marker. This study aimed to explore the association between MHR and Brachial-ankle pulse wave velocity (Ba-PWV) in adult Chinese participants. A total of 2029 participants were divided into two groups according to the Ba-PWV: a high Ba-PWV group (Ba-PWV ≥1400 cm/s) and a low Ba-PWV group (Ba-PWV < 1400 cm/s). According to the cut-off points of quartile of MHR, the participants were divided into four groups. The relationship between MHR and Ba-PWV was analyzed. After adjusting for potential confounders, a non-linear relationship between MHR and Ba-PWV was found in the participants, and the inflection point was 7.78 in the non-linear curve. On the left of the inflection point, MHR had a positive correlation with Ba-PWV (OR = 1.17, 95% confidence interval (CI): 1.08 to 1.28, p < 0.01). However, there was no obvious relationship between MHR and Ba-PWV on the right of the inflection point (OR = 0.96, 95% CI: 0.90 to 1.01, p = 0.117). Further demographic analysis demonstrated that the positive relationship between MHR and Ba-PWV was found in the female participants with hypertension family history, but without a current history of hypertension, smoking, or drinking (p < 0.05). An increased MHR is a risk factor of atherosclerosis, which may predict the potential development of atherosclerosis. When the MHR is close to 7.78, it has the highest predictive value for the risk of atherosclerosis occurrence.

Sonodynamic therapy in atherosclerosis by curcumin nanosuspensions: Preparation design, efficacy evaluation, and mechanisms analysis

Previous studies have shown that curcumin (Cur) induced by ultrasound has protective effects on atherosclerosis even if low bioavailability of the Cur. The enhancement of bioavailability of the Cur further improved the curative effect of sonodynamic therapy (SDT) on atherosclerosis through nanotechnology. Nanosuspensions as a good drug delivery system had obvious advantages in increasing the solubility and improving the effectiveness of insoluble drugs. The aim of this study was to develop curcumin nanosuspensions (Cur-ns) which used polyvinylpyrrolidone (PVPK30) and sodium dodecyl sulfate (SDS) as stabilizers to improve poor water solubility and bioavailability of the Cur. And then the therapeutic effects of Cur-ns-SDT on atherosclerotic plaques and its possible mechanisms would be investigated and elucidated. Cur-ns with a small particle size has been successfully prepared and the data have confirmed that Cur-ns could be more easily engulfed into RAW264.7 cells than free Cur and accumulated more under the stimulation of the ultrasound. Reactive oxygen species (ROS) inside RAW264.7 cells after SDT led to the decrease of mitochondrial membrane potential (MMP) and the higher expression of cleaved caspase-9/3. The results of in vivo experiments showed that Cur-ns-SDT reduced the level of total cholesterol (TC) and low density lipoprotein (LDL) and promoted the transformation from M1 to M2 macrophages, relieved atherosclerosis syndrome. Therefore, Cur-ns-SDT was a potential treatment of anti-atherosclerosis by enhancing macrophages apoptosis through mitochondrial pathway and inhibiting the progression of plaques by interfering with macrophages polarization.

[Dynamics of brain CD68+ and stabilin-1+ macrophage infiltration in patients with myocardial infarction]

Te aim of the study was to evaluate the temporal dynamics of brain CD68+ and stabilin-1+ macrophage infltration in patients with fatal myocardial infarction (MI) type 1.

MATERIALS AND METHODS

Te study included 31 patients with fatal MI type I. Te control group comprised 10 patients of 18-40 age group who died from injuries incompatible with life. Patients with MI were divided into two groups. Group 1 comprised patients who died during the frst 72 hours of MI, group 2 comprised patients who died on days 4‒28. Macrophage infltration in the brain was assessed by immunohistochemical analysis. We used CD68 as a marker for the cells of the macrophage lineage and stabilin-1 as an M2-like macrophage biomarker.

RESULTS

In group 1 the number of brain CD68+ macrophages was signifcantly higher than in the control group. In group 2 the intensity of brain CD68+ cells infltration was lower than in group 1 and higher than in the control group. Tere was a small amount of stabilin-1+ macrophages in the brain of healthy people, as well as of patients who died from MI. Tere were no signifcant differences in the number of stabilin-1+ cells between group 1 and group 2. Correlation analysis revealed the presence of positive correlation between the number of CD68 + macrophages in the infarct, peri-infarct, and non-infarct areas of the myocardium and the number of CD68+ macrophages in the brain in patients with MI. Tere were not correlations between the number of CD68 + and stabilin-1+ cells and the presence of diabetes mellitus, history of stroke, history of MI, and pre-infarction angina.

CONCLUSION

Te number of brain CD68+ macrophages signifcantly increased during the frst three days of MI. Te number of brain stabilin-1+ macrophages did not increase and did not differ from the control values. We observed a positive correlation between the number of CD68+ macrophages in the brain and myocardium.

Potential injurious effects of the fine particulate PM2.5 on the progression of atherosclerosis in apoE-deficient mice by activating platelets and leukocytes

INTRODUCTION

Exposure to the fine particulate matter PM2.5 is strongly associated with atherosclerotic diseases, creating considerable public concern. Nevertheless, the mechanisms have not been fully elucidated. We exposed atherosclerosis-prone apoE-deficient mice to PM2.5 to begin investigating these mechanisms.

MATERIAL AND METHODS

Thirty-two 8-week-old male apoE^-/- mice were divided to two groups fed with high-fat diet: a control group instilled with 0.9% saline, and an experimental group instilled with PM2.5 (30 mg/kg/day) for 8 weeks. We measured PM2.5 in whole blood by the ICP-MS method, and lipids and inflammatory factors by standard methods. The whole descending arteries were stained with oil red O; Aortic roots were stained with Movat, Sirius Red and immunohistochemical stains for pathological analysis; Brachiocephalic arteries for scanning electron microscopy, the descending arteries for Q-PCR. Echocardiography was used to evaluate cardiac function.

RESULTS

In PM2.5 group, we observed elevated heavy metal components, consistent with higher amounts of platelets in total blood. The PM2.5 group also had elevated serum inflammatory factor levels. Finally, the PM2.5 group showed larger atherosclerotic plaques (p = 0.0231), higher numbers of lesion macrophages (p = 0.0183), greater injury to endothelial layers with greater adherence of platelets and leukocytes, elevated inflammatory factor levels, the NAD(P)H oxidase subunits p22phox and p47phox (p = 0.0079 and p = 0.0294), the M1/M2 associated markers IL-6, TNF-α (p = 0.0291, p = 0.0286), iNOS, IL-12 (p = 0.0122 and p = 0.0280) and arginase-1, and CD206 (p = 0.0216 and p = 0.0317).

CONCLUSIONS

PM2.5 exposure activated circulating leukocytes, platelets and associated inflammatory factors, contributing to the progression of atherosclerosis in apoE^-/- mice.

BLTR1 and CD36 Expressing Microvesicles in Atherosclerotic Patients and Healthy Individuals

Aims: Monocytes/macrophages play a crucial role in the development, progression, and complication of atherosclerosis. In particular, foam cell formation driven by CD36 mediated internalization of oxLDL leads to activation of monocytes and subsequent release of microvesicles (MVs) derived from monocytes (MMVs). Further, pro-inflammatory leukotriene B4 (LTB4) derived from arachidonic acid promotes atherosclerosis through the high-affinity receptor BLTR1. Thus, we aimed to investigate the correlation between different MMV phenotypes (CD14⁺ MVs) on the one hand, and arachidonic acid and eicosapentaenoic acid contents in different compartments including atherosclerotic plaques, plasma, and granulocytes on the other.

Methods and Results: Samples from patients with femoral atherosclerosis and healthy controls were analyzed on an Apogee A60 Micro-PLUS flow cytometer. Platelet-poor plasma was labeled with lactadherin-FITC, anti-CD14-APC, anti-CD36-PE, and anti-BLTR1-AF700. Eicosapentaenoic acid and arachidonic acid content in different compartments in patients were analyzed using gas chromatography. Compared to controls, patients had lower levels of BLTR1⁺ MVs (p = 0.007), CD14⁺BLTR1⁺ MVs (p = 0.007), and CD14⁺BLTR1⁺CD36⁺ MVs (p = 0.001). Further, in patients CD14⁺ MVs and CD14⁺CD36⁺ MVs correlated inversely with arachidonic acid in granulocytes (r = −0.302, p = 0.039 and r = −0.322, p = 0.028, respectively). Moreover, CD14⁺CD36⁺ MVs correlated inversely with arachidonic acid in plasma phospholipids in patients (r = −0.315, p = 0.029), and positively with triglyceride in both patients (r = 0.33, p = 0.019) and controls (r = 0.46, p = 0.022).

Conclusion: This is the first study of its kind and thus the results are explorative and only indicative. BLTR1⁺ MVs and CD14⁺CD36⁺ MVs has potential as markers of atherosclerosis pathophysiology, but this needs further investigation.

Monocytes and Macrophages as Viral Targets and Reservoirs

Viruses manipulate cell biology to utilize monocytes/macrophages as vessels for dissemination, long-term persistence within tissues and virus replication. Viruses enter cells through endocytosis, phagocytosis, macropinocytosis or membrane fusion. These processes play important roles in the mechanisms contributing to the pathogenesis of these agents and in establishing viral genome persistence and latency. Upon viral infection, monocytes respond with an elevated expression of proinflammatory signalling molecules and antiviral responses, as is shown in the case of the influenza, Chikungunya, human herpes and Zika viruses. Human immunodeficiency virus initiates acute inflammation on site during the early stages of infection but there is a shift of M1 to M2 at the later stages of infection. Cytomegalovirus creates a balance between pro- and anti-inflammatory processes by inducing a specific phenotype within the M1/M2 continuum. Despite facilitating inflammation, infected macrophages generally display abolished apoptosis and restricted cytopathic effect, which sustains the virus production. The majority of viruses discussed in this review employ monocytes/macrophages as a repository but certain viruses use these cells for productive replication. This review focuses on viral adaptations to enter monocytes/macrophages, immune escape, reprogramming of infected cells and the response of the host cells.

Hemodialysis-related changes in phenotypical features of monocytes

Hemodialysis (HD) patients exhibit chronic inflammation and leukocyte activation. We investigated the surface-marker profile of monocytes by flow cytometry to assess the chronic effect of uremia and the acute effect of dialysis on their phenotypical and functional features in 16 healthy controls (CON) and 15 HD patients before and after a polysulfone-based dialysis session. Median fluorescence intensities were analyzed indicating expression of CD14, CD16, integrins (CD11b, CD18), chemokine receptors (CCR2, CX3CR1), scavenger receptors (CD36, CD163) and Toll-like receptor-2 (TLR2). Before and after dialysis, HD patients harbour 0.9-fold less CD14⁺⁺CD16^- (Mo1), 1.8-fold more CD14⁺⁺CD16⁺ (Mo2) and CD14⁺CD16⁺⁺ (Mo3) monocytes than CON. HD patients' Mo1 showed elevated expression of CD11b (1.7-fold), CD18 (1.2-fold) and CD36 (2.1-fold), whereas CD163 expression was reduced in Mo1 and Mo2 (0.6-fold) compared to CON. These markers remained unaffected by dialysis. CX3CR1 expression on Mo2 and Mo3 was lower in HD patients before (0.8-fold) and further diminished after dialysis (0.6-fold). Stimulation of monocytes resulted in diminished responses in HD patients compared to CON. In conclusion, a systematic analysis of the expression of particular surface markers on distinct monocyte subsets may help to distinguish between uremia and/or dialysis induced effects and to evaluate the functionality of monocytes and biocompatibility of HD.

Increased ROS production and DNA damage in monocytes are biomarkers of aging and atherosclerosis

Background

New evidence demonstrates that aging and dyslipidemia are closely associated with oxidative stress, DNA damage and apoptosis in some cells and extravascular tissues. However, in monocytes, which are naturally involved in progression and/or resolution of plaque in atherosclerosis, this concurrence has not yet been fully investigated. In this study, we evaluated the influence of aging and hypercholesterolemia on serum pro-inflammatory cytokines, oxidative stress, DNA damage and apoptosis in monocytes from apolipoprotein E-deficient (apoE^−/−) mice compared with age-matched wild-type C57BL/6 (WT) mice. Experiments were performed in young (2-months) and in old (18-months) male wild-type (WT) and apoE^−/− mice.

Results

Besides the expected differences in serum lipid profile and plaque formation, we observed that atherosclerotic mice exhibited a significant increase in monocytosis and in serum levels of pro-inflammatory cytokines compared to WT mice. Moreover, it was observed that the overproduction of ROS, led to an increased DNA fragmentation and, consequently, apoptosis in monocytes from normocholesterolemic old mice, which was aggravated in age-matched atherosclerotic mice.

Conclusions

In this study, we demonstrate that a pro-inflammatory systemic status is associated with an impairment of functionality of monocytes during aging and that these parameters are fundamental extra-arterial contributors to the aggravation of atherosclerosis. The present data open new avenues for the development of future strategies with the purpose of treating atherosclerosis.

Metabolomic characterization of hypertension and dyslipidemia

BACKGROUND

Hypertension and dyslipidemia are two main risk factors for cardiovascular diseases (CVD). Moreover, their coexistence predisposes individuals to a considerably increased risk of CVD. However, the regulatory mechanisms involved in hypertension and dyslipidemia as well as their interactions are incompletely understood.

OBJECTIVES

The aims of our study were to identify metabolic biomarkers and pathways for hypertension and dyslipidemia, and compare the metabolic patterns between hypertension and dyslipidemia.

METHODS

In this study, we performed metabolomic investigations into hypertension and dyslipidemia based on a "healthy" UK population. Metabolomic data from the Husermet project were acquired by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-mass spectrometry. Both univariate and multivariate statistical methods were used to facilitate biomarker selection and pathway analysis.

RESULTS

Serum metabolic signatures between individuals with and without hypertension or dyslipidemia exhibited considerable differences. Using rigorous selection criteria, 26 and 46 metabolites were identified as potential biomarkers of hypertension and dyslipidemia respectively. These metabolites, mainly involved in fatty acid metabolism, glycerophospholipid metabolism, alanine, aspartate and glutamate metabolism, are implicated in insulin resistance, vascular remodeling, macrophage activation and oxidised LDL formation. Remarkably, hypertension and dyslipidemia exhibit both common and distinct metabolic patterns, revealing their independent and synergetic biological implications.

CONCLUSION

This study identified valuable biomarkers and pathways for hypertension and dyslipidemia, and revealed common and different metabolic patterns between hypertension and dyslipidemia. The information provided in this study could shed new light on the pathologic mechanisms and offer potential intervention targets for hypertension and dyslipidemia as well as their related diseases.

Mucosal Chemokines

Several chemokines have important functions in mucosal immunity. While there are many chemokines, 4 of them (CCL25, CCL28, CXCL14, and CXCL17) are especially important in mucosal immunity because they are homeostatically expressed in mucosal tissues. Of these, only CCL25 and CCL28 have been widely recognized as mucosal chemokines. In this study, we review the physiology of these chemokines with specific emphasis on their function in mucosal immunity. CCL25 recruits certain important subsets of T cells that express CCR9 to the small intestine. These CCR9⁺ T cells also express the integrin α4β7 and have been shown to play important roles in the control of intestinal inflammation. CCL28 recruits CCR10⁺ IgA plasmablasts to the lactating mammary gland. The role of CXCL14 in mucosal immunity is less well defined, but a Cxcl14^-/- mouse exhibits significant metabolic abnormalities. Finally, CXCL17 was the last chemokine to be described and signals through a new chemokine receptor (GPR35/CXCR8), which is expressed in a subset of macrophages that are recruited to mucosal tissues by this chemokine. We conclude that these 4 chemokines play very important roles in mucosal immunity and their continued functional characterization will likely identify novel therapeutic targets.

Cardiac CD68+ and stabilin-1+ macrophages in wound healing following myocardial infarction: From experiment to clinic

Myocardial infarction (MI) remains the leading cause of mortality and morbidity throughout the world. Macrophages are key innate immune cells that play a significant role in transition from the inflammatory to the regenerative phase during wound healing following MI. The scavenger receptor stabilin-1 is one of the most interesting macrophage biomarkers. This receptor contributes to wound healing, angiogenesis, and tissue remodeling. We suggested a research protocol using macrophage biomarkers to study the cellular basis of cardiac remodeling and healing in patients with acute MI. The purpose of the research was to translate experimental knowledge regarding macrophage subsets and their biomarkers in post-infarction myocardial regeneration into results observed in clinical settings. The study included 41 patients with fatal MI type 1. All patients were divided into four groups according to the timeline of MI histopathology. In addition to routine histopathological analysis, macrophage infiltration was assessed by immunohistochemistry. We used CD68 as a marker for the cells of the macrophage lineage and stabilin-1 as an M2-like macrophage biomarker. The number of CD68+ and stabilin-1+ macrophages in the infarct area increased and peaked in the regenerative phase and did not decrease in the late stage of MI. In the peri-infarct area, the number of CD68+ macrophages increased in the inflammatory phase, peaked during the reparative phase, and did not decrease in the late phase, while the number of stabilin-1+ macrophages increased in the regenerative phase and remained unchanged. Additionally, in the reparative phase, we observed increase in the number of CD68+ and stabilin-1+ macrophages in the non-infarct area. The research protocol suggested allowed us to translate experimental knowledge regarding macrophage subsets and their biomarkers in post-infarction myocardial regeneration into clinical data. Taken together, these results demonstrated biphasic cardiac macrophage response following acute MI somewhat similar to that in a murine model. The increase in stabilin-1+ macrophage infiltration noticed in the myocardium during the regenerative phase and the strong positive correlation between the number of these cells and timeline of MI histopathology enabled us to propose stabilin-1 as a diagnostic macrophage biomarker in myocardium wound healing in patients with acute MI.

Broadleaf Mahonia attenuates granulomatous lobular mastitis‑associated inflammation by inhibiting CCL‑5 expression in macrophages

Granulomatous lobular mastitis (GLM) is a type of chronic mammary inflammation with unclear etiology. Currently systematic corticosteroids and methitrexate are considered as the main drugs for GLM treatment, but a high toxicity and risk of recurrence greatly limit their application. It is therefore an urgent requirement that safe and efficient natural drugs are found to improve the GLM prognosis. Broadleaf Mahonia (BM) is a traditional Chinese herb that is believed to have anti-inflammatory properties according to ancient records of traditional Chinese medicine. The present study investigated this belief and demonstrated that BM significantly inhibited the expression of interleukin-1β (IL-1β), IL-6, cyclooxygenase-2 and inducible nitric oxide synthase in RAW264.7 cells, but had little influence on the cell viability, cell cycle and apoptosis. Meanwhile, the lipopolysaccharide-induced elevation of reactive oxygen species and nitric oxide was also blocked following BM treatment, accompanied with decreased activity of nuclear factor-κB and MAPK signaling. A cytokine array further validated that BM exhibited significant inhibitory effects on several chemoattractants, including chemokine (C-C motif) ligand (CCL)-2, CCL-3, CCL-5 and secreted tumor necrosis factor receptor 1, among which CCL-5 exhibited the highest inhibition ratio in cell and clinical GLM specimens. Collectively, the results show that BM is a novel effective anti-inflammatory herb in vitro and ex vivo, and that CCL-5 may be closely associated with GLM pathogenesis.

Monocytes from patients with Primary Ciliary Dyskinesia show enhanced inflammatory properties and produce higher levels of pro-inflammatory cytokines

Patients with Primary Ciliary Dyskinesia (PCD) suffer from recurrent upper and lower airway infections due to defects in the cilia present on the respiratory epithelium. Since chronic inflammatory conditions can cause changes in innate immune responses, we investigated whether monocytes isolated from the peripheral blood of pediatric PCD patients respond differently to inflammatory stimuli, compared to monocytes from healthy children and adults. The receptor for C5a (C5aR) was upregulated in PCD, whereas expression levels of the leukocyte chemoattractant receptors CCR1, CCR2, CCR5, BLT1 and FPR1 on PCD monocytes were similar to those on monocytes from healthy individuals. Also in vitro migration of PCD monocytes towards the ligands of those receptors (CCL2, fMLP, C5a and LTB4) was normal. Compared to healthy children, PCD patients had a higher percentage of the non-classic monocyte subset (CD14+CD16++) in circulation. Finally, PCD monocytes produced higher levels of pro-inflammatory cytokines (IL-1β and TNF-α) and chemokines (CCL3, CCL5, CCL18 and CCL22) in response to LPS, peptidoglycan and/or dsRNA stimulation. These data suggest that monocytes might exacerbate inflammatory reactions in PCD patients and might maintain a positive feedback-loop feeding the inflammatory process.

Gene expression analysis of whole blood RNA from pigs infected with low and high pathogenic African swine fever viruses

African swine fever virus (ASFV) is a macrophage-tropic virus responsible for ASF, a transboundary disease that threatens swine production world-wide. Since there are no vaccines available to control ASF after an outbreak, obtaining an understanding of the virus-host interaction is important for developing new intervention strategies. In this study, a whole transcriptomic RNA-Seq method was used to characterize differentially expressed genes in pigs infected with a low pathogenic ASFV isolate, OUR T88/3 (OURT), or the highly pathogenic Georgia 2007/1 (GRG). After infection, pigs infected with OURT showed no or few clinical signs; whereas, GRG produced clinical signs consistent with acute ASF. RNA-Seq detected the expression of ASFV genes from the whole blood of the GRG, but not the OURT pigs, consistent with the pathotypes of these strains and the replication of GRG in circulating monocytes. Even though GRG and OURT possess different pathogenic properties, there was significant overlap in the most upregulated host genes. A small number of differentially expressed microRNAs were also detected in GRG and OURT pigs. These data confirm previous studies describing the response of macrophages and lymphocytes to ASFV infection, as well as reveal unique gene pathways upregulated in response to infection with GRG.

Change in gut microbiota is correlated with alterations in the surface molecule expression of monocytes after Roux-en-Y gastric bypass surgery in obese type 2 diabetic patients

Objectives: Persistent low-grade chronic inflammation is common in type 2 diabetes (T2D) and obesity. To date, the underlying molecular mechanism is not well understood. In this study, we aimed to investigate gut microbiota and the expression of monocyte surface molecules in obese T2D subjects who underwent Roux-en-Y gastric bypass (RYGB) surgery. Methods: Twenty-four T2D patients were enrolled. Gut microbiota was assessed by measuring bacterial DNA. The phenotypes and biological functions of monocytes, and the expression of monocyte surface molecules were examined by flow cytometry. Results: RYGB led to significant alterations in the phenotypes of monocytes. Moreover, the ability of monocyte migration was significantly decreased after RYGB (P<0.05), which was consistent with reduced Chemokine-receptors CCR2 expression of CD14⁺CD16⁺ monocytes (P<0.05) and CX3CR1 expression of the three monocytes subsets (P<0.05). RYGB also resulted in a shift of gut microbiota in the obese T2D patients. Spearman's rank correlation coefficient showed a link between gut microbiota and monocyte subsets where the increased Bacteroidetes was negatively correlated with the variation of CD14^dimCD16⁺ monocyte percentage (r=-0.477, P<0.05). Furthermore, the decreased counts of Escherichia were positively correlated with the variation of TNF-α secretion (r=0.442, P<0.05) and TLR4 (r=0.425, P<0.05) expression onCD14⁺CD16⁺ monocytes. Conclusions: This study, for the first time, demonstrated a link between the changes in gut microbiota and alterations in both phenotypes and functions of monocytes after RYGB, which may contribute significantly to the low-grade chronic inflammation in obese T2D patients.

Hyperglycemia induces mixed M1/M2 cytokine profile in primary human monocyte-derived macrophages

Hyperglycaemia is a key factor in diabetic pathology. Macrophages are essential regulators of inflammation which can be classified into two major vectors of polarisation: classically activated macrophages (M1) and alternatively activated macrophages (M2). Both types of macrophages play a role in diabetes, where M1 and M2-produced cytokines can have detrimental effects in development of diabetes-associated inflammation and diabetic vascular complications. However, the effect of hyperglycaemia on differentiation and programming of primary human macrophages was not systematically studied. We established a unique model to assess the influence of hyperglycaemia on M1 and M2 differentiation based on primary human monocyte-derived macrophages. The effects of hyperglycaemia on the gene expression and secretion of prototype M1 cytokines TNF-alpha and IL-1beta, and prototype M2 cytokines IL-1Ra and CCL18 were quantified by RT-PCR and ELISA. Hyperglycaemia stimulated production of TNF-alpha, IL-1beta and IL-1Ra during macrophage differentiation. The effect of hyperglycaemia on TNF-alpha was acute, while the stimulating effect on IL-1beta and IL-1Ra was constitutive. Expression of CCL18 was supressed in M2 macrophages by hyperglycaemia. However the secreted levels remained to be biologically significant. Our data indicate that hyperglycaemia itself, without additional metabolic factors induces mixed M1/M2 cytokine profile that can support of diabetes-associated inflammation and development of vascular complications.