Immunological Aspects of Infertility-The Role of KIR Receptors and HLA-C Antigen

The mechanisms of immune tolerance of a mother against an antigenically foreign fetus without a concomitant loss of defense capabilities against pathogens are the factors underlying the success of a pregnancy. A significant role in human defense is played by killer immunoglobulin-like receptor (KIR) receptors, which regulate the function of the natural killer (NK) cells capable of destroying antigenically foreign cells, virus-infected cells, or tumor-lesioned cells. A special subpopulation of NK cells called uterine NK cells (uNK) is found in the uterus. Disruption of the tolerance process or overactivity of immune-competent cells can lead to immune infertility, a situation in which a woman's immune system attacks her own reproductive cells, making it impossible to conceive or maintain a pregnancy. Since the prominent role of the inflammatory response in infertility, including KIR receptors and NK cells, has been postulated, the process of antigen presentation involving major histocompatibility complex (MHC) molecules (HLA) appears to be crucial for a successful pregnancy. Proper interactions between KIR receptors on female uNK cells and HLA class I molecules, with a predominant role for HLA-C, found on the surface of germ cells, are strategically important during embryo implantation. In addition, maintaining a functional balance between activating and inhibitory KIR receptors is essential for proper placenta formation and embryo implantation in the uterus. A disruption of this balance can lead to complications during pregnancy. The discovery of links between KIR and HLA-C has provided valuable information about the complexity of maternal-fetal immune interactions that determine the success of a pregnancy. The great diversity of maternal KIR and fetal HLA-C ligands is associated with the occurrence of KIR/HLA-C combinations that are more or less favorable for reproductive success.

Neutrophil microRNAs

Neutrophils are considered 'first-line defence' cells as they can be rapidly recruited to the site of the immune response. As key components of non-specific immune mechanisms, neutrophils use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to fight pathogens. Recently, immunoregulatory abilities of neutrophils associated with the secretion of several mediators, including cytokines and extracellular vesicles (EVs) containing, among other components, microRNAs (miRNAs), have also been reported. EVs are small structures released by cells into the extracellular space and are present in all body fluids. Microvesicles show the composition and status of the releasing cell, its physiological state, and pathological changes. Currently, EVs have gained immense scientific interest as they act as transporters of epigenetic information in intercellular communication. This review summarises findings from recent scientific reports that have evaluated the utility of miRNA molecules as biomarkers for effective diagnostics or even as start-points for new therapeutic strategies in neutrophil-mediated immune reactions. In addition, this review describes the current state of knowledge on miRNA molecules, which are endogenous regulators of gene expression besides being involved in the regulation of the immune response.

Cadmium Toxicity and Health Effects-A Brief Summary

Cadmium (Cd) is a ductile metal in the form of a blueish or silvery-white powder. It is naturally found in soil (about 0.2 mg/kg), minerals, and water. Cd belongs to the group of toxic, carcinogenic, and stimulating elements. Its biological half-life in the human body ranges from 16 to even 30 years on average. Some lung diseases (such as emphysema, asthma, and bronchitis) and high blood pressure are thought to be related to slow poisoning. The symptoms of cadmium poisoning may vary depending on the time of exposure, the type of diet, and the age and health status of the exposed people. For non-smokers and non-occupational exposures, the only source of exposure is diet. The FAO/WHO recommends that the tolerable cadmium intake for an adult is approximately 0.4-0.5 mg/week (60-70 µg per day). Cadmium is primarily absorbed through the respiratory system (about 13-19% of Cd from the air), but it can also enter through the digestive system (about 10-44%), when dust is mixed and swallowed with saliva. The amount of accumulated Cd ranges from 0.14 to 3.2 ppm in muscles, 1.8 ppm in bones, and 0.0052 ppm in the blood. People who are most frequently exposed to heavy metals should be continuously monitored in order to maintain a healthy lifestyle, as well as to implement effective preventive measures and improve public health.

Immunoaging - the effect of age on serum levels of NET biomarkers in men: a pilot study

OBJECTIVES

The study aimed to evaluate the impact of aging on the formation of neutrophil extracellular traps (NETs). The impaired formation of NETs is the cause of an abnormal innate immune response.

MATERIAL AND METHODS

The study included a total of 45 healthy male subjects of different age groups. Whole blood was collected from the subjects, and the concentration of myeloperoxidase (MPO), the main biocidal protein in NETs, was determined in serum using ELISA. The serum levels of circulating free DNA (cfDNA), which are the structural basis of NETs, were also measured by fluorescence. In addition, the white blood cell count was determined, whole blood smear was evaluated, and the neutrophillymphocyte ratio was calculated. The variations in the levels of NET biomarkers were analyzed in different age groups.

RESULTS

The low levels of MPO (243.70 ng/ml) and cfDNA (6.24 ng/100 μl) in boys indicated neutrophil insufficiency for NETosis in children. A progressive increase in the levels of MPO and cfDNA with age was observed among adolescents (420.91, p = 0.04; 13.55, p = 0.03, respectively), with the highest level noted in the healthy adult group (466.58, p = 0.01; 14.07, p = 0.01, respectively). The levels of the studied parameters were comparable in adolescents and young adults, which proved that the NETosis process was appropriate and suggested the attainment of neutrophil maturity for the release of NETs in adolescence. The levels of MPO and cfDNA were low in older men (225.46, p < 0.01; 5.19, p < 0.01, respectively) indicating impaired NET formation.

CONCLUSIONS

Data on the generation of NETs in different age groups obtained in this study can allow a better understanding of the ontogenesis of the immune system in terms of the course of NETosis, and also indicate the need to support nonspecific responses in children and adults. Further research should be performed to determine the possibility of regulating the NETosis process. Int J Occup Med Environ Health. 2023;36(3):333-48.

Unobvious Neutrophil Extracellular Traps Signification in the Course of Oral Squamous Cell Carcinoma: Current Understanding and Future Perspectives

Background: The current standards of treatment for oral squamous cell carcinoma (OSCC) include surgery, radiotherapy, and chemotherapy. In recent years, research on the effectiveness of immunotherapy in the treatment of OSCC has also been conducted.Purpose: Studies indicate that nonspecific immune mechanisms involved in the course of the anticancer response also need to be taken into account.Research Design: This review summarizes the results of our research on the active participation of neutrophils, which are previously underestimated, in the antitumor response in the course of OSCC, taking into account the ability of these cells to generate neutrophil extracellular traps (NETs).Results: We proved that the formation of NETs accompanies not only inflammatory changes but also the neoplastic process and that lipopolysaccharide (LPS) or interleukin 17 (IL-17) plays a critical role in inducing the formation of NETs during the OSCC. The greatest achievement of our published findings was the demonstration of the formation and release of NETs from neutrophils cocultured with tumor cells, as well as after stimulation with supernatant from the SCC culture with a PI3K-independent Akt kinase activation mechanism. Moreover, the pioneering achievement of our studies was the localization of NET structures in the tumor tissue, as well as the observation of high concentrations of NET markers in the serum of OSCC patients with low concentrations in the saliva, indicating the differences in the course of immune response between the periphery and the local reactions.Conclusions: The data presented here provide surprising but important information on the role of NETs in the course of OSCC, thus pointing to a promising new direction in the development of management strategies for early noninvasive diagnosis and monitoring of the disease course, and perhaps immunotherapy. Furthermore, this review raises further questions and elaborates on the process of NETosis in cancer.

Investigation of estrogen-like effects of parabens on human neutrophils

This study investigated the estrogen-like effects and mechanism of action most commonly used parabens: methyl- (MeP), ethyl- (EtP), propyl- (PrP) and butylparaben (BuP) in human neutrophils. Neutrophils were isolated from 50 blood donors, pre-incubated with antagonists of estrogen receptor α (ERα), ERβ and G-protein coupled estrogen receptor 1 (GPER), then incubated with MeP, EtP, PrP, BuP and 17β-estradiol (E2; 10 nM). Cytotoxic effect was evaluated by MTT test. Neutrophils apoptosis, necrosis and NETs formation were assessed in flow cytometry and confocal microscopy. The ability of the neutrophils for chemotaxis, phagocytosis, NADPH oxidase activity and generation of superoxide anion was assessed in Boyden's chamber, Park's method with latex, the NBT test, and reduction of cytochrome C, respectively. The total nitric oxide concentration was measured in neutrophils supernatants by the Griess reaction. The expression of cathepsin G, neutrophil elastase, proteinase 3, ERα, ERβ and GPER was assessed in Western blot method. In our research, parabens did not cause a cytotoxic effect on human neutrophils nor affect their lifespan. Parabens exposure did not change neutrophils functions (chemotaxis, phagocytosis, NETs formation and oxygen-dependent killing mechanism) and expression of estrogen receptors. Our results suggest that parabens do not cause estrogen receptor-mediated neutrophils-related effects at concentrations measured in the plasma of individuals using products preserved with parabens.

Bisphenol A: Potential Factor of Miscarriage in Women in the Context of the Phenomenon of Neutrophil Extracellular Traps

Humans are exposed to a number of environmental pollutants every day. Among them, endocrine disruptors are particularly harmful to human health. Bisphenol A (BPA) is a xenoestrogen that has been shown to disrupt the endocrine system and cause reproductive toxicity. In this study, we aimed to verify the potential relationship between BPA and miscarriage involving the formation of neutrophil extracellular traps (NETs). Blood samples were collected from healthy women and women who had miscarriage in the first trimester of pregnancy. The serum levels of cytoplasmic anti-PR3 antibody and perinuclear anti-MPO antibody were determined using an immunoenzymatic method. The concentrations of key proinflammatory proteins TNF-α and MCP-1, as well as NADPH oxidase subunits NOX1 and NCF2, were also measured in the serum samples. The serum concentration of BPA was determined using gas chromatography. The results showed that the concentrations of BPA were significantly elevated in the serum of women who had miscarriage compared to the control group, with the highest concentration found in the “NETs-positive” group. The levels of MCP-1 and TNF-α were significantly higher in the “NETs-positive” group compared to the “NETs-negative” and control group. The levels of NOX1 and NCF2 were also higher in the “NETs-positive” group compared to the “NETs-negative” group. The study showed that BPA could play a role in the course of miscarriage through the formation of NETs. The results indicate the need to limit the exposure of women planning pregnancy to xenoestrogens, including BPA.

NETs biomarkers in saliva and serum OSCC patients: One hypothesis, two conclusions

PURPOSE

The actual role of neutrophils and neutrophil extracellular traps (NETs) in the course of cancer has not been clearly defined. The aim of this study was to determine the clinical usefulness of NETs biomarkers in saliva in confrontation with the blood serum and tumor tissue as a potential prognostic and therapeutic target in patients with oral squamous cell carcinoma (OSCC).

MATERIAL AND METHODS

Expression of myeloperoxidase (MPO), and histones H2A, H2B, H3 in the tumor tissue, was investigated using immunohistochemistry. The expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits: p47-phox, p67-phox (neutrophil cytosolic factor 2, NCF2) and panRac, as well as citrullinated histone H3 (CitH3) in peripheral blood neutrophil lysates, was assessed via Western blot. ELISA tests were employed to measure the concentrations of circulating free DNA (cfDNA) and MPO in saliva only, and NOX1, NCF2, DNASE1 in saliva and serum.

RESULTS

Extracellular expression of MPO and histones was localized within tumor tissue. Significantly lower expression of p67-phox, panRac, and CitH3 was determined in OSCC patients. Considerably lower concentrations of NOX1, NCF2, and DNASE1 in the saliva samples of cancer patients were observed. However, the levels of NOX1, NCF2, and DNASE1 in the serum of patients with cancer were substantially higher.

CONCLUSIONS

The results obtained from the saliva of cancer patients suggest an impairment of the immunological homeostasis within the oral cavity related to NET formation, the causes of which should be sought in deficient activation of NADPH oxidase.

The diagnostic potential of novel biomarkers of hypertension in men

INTRODUCTION

The present study aimed to evaluate the diagnostic usefulness of selected novel parameters as biomarkers of hypertension: miR-145-5p, miR-1-3p, miR-423-5p, PCSK9, MyBPC3, NOX1, and CYBb, and NCF2, DNase 1, anti-MPO and anti-PR3 antibodies.

METHODS

We present the data of men with normal blood pressure, diagnosed hypertension, confirmed hypertension, and hypertension and coexisting coronary artery disease.

RESULTS

Elevated levels of miR-145-5p, miR-1-3p, and miR-423-5p and high levels of PCSK9, MyBPC3, and DNase 1 were observed in all groups of hypertensive men. We showed decreased levels of NOX1 and CYBb, and an elevated level of NCF2.

CONCLUSIONS

PCSK9 shows the greatest potential as an early biomarker of screening-detected hypertension.

Methylparaben-induced regulation of estrogenic signaling in human neutrophils

Parabens, including the most common methylparaben (MeP), are popular preservatives, which possess estrogenic activity. The aims of this study were to assess the impact of MeP on estrogen receptors (ERs) and/or NF-κB-dependent generation of IL-8 and production of nitric oxide (NO), and also to verify the hypothesis about the crosstalk of ERs with NF-κB in xenoestrogen-exposed neutrophils. Human neutrophils were incubated for 20-h with MeP (0.06 μM) and/or ER antagonist (1 μM) and/or NF-κB inhibitor (100 μM). After the isolation of cell lysates and cytoplasmic and nuclear fraction, the expression of ERα, ERβ, p-IKKα/β, p65 NF-κB, and inducible nitric oxide synthase (iNOS) was measured by Western blot analysis, The concentration of NO was evaluated by Griess reaction, and that of IL-8 was measured by ELISA. The results showed that MeP modulated the expression of ERα, but not ERβ. Exposure to paraben activated iKKα/β-dependent NF-κB pathway, but translocation of p65 NF-κB into the cell nucleus was inhibited by ERs. MeP also decreased the iNOS-dependent production of NO, but did not influence the secretion of IL-8 by neutrophils. The study indicates that MeP may affect the functioning of human neutrophils by modulating intracellular signal transduction pathways, including ERs and NF-κB pathway.

Cancers Cells in Traps? The Pathways of NETs Formation in Response to OSCC in Humans-A Pilot Study

The aim of the experiment was to evaluate the process of neutrophil extracellular traps (NETs) formation in patients with oral squamous cell carcinoma (OSCC) in response to direct or indirect contact with SCC cells in comparison to results obtained in the cells of healthy subjects. To fulfill study objectives CAL 27 cell line and blood were obtained from cancer patients and control subjects. Parameters related to NETs formation were analyzed utilizing flow cytometry, fluorescence microscopy, and ELISA-type tests. The expression of selected phosphorylated proteins of the PI3K/Akt/PBK pathway in neutrophils was evaluated using the Western blot method. An increase in NETs formation was observed in a coculture of neutrophils with SCC cells, with the largest amount of NETs formed after stimulation with a supernatant obtained from the SCC culture. The enhanced process of NETs formation was accompanied by changes in the expression of proteins from the PI3K/Akt/PBK pathway. The obtained results prove the existence of interactions between neutrophils and cancer cells resulting in NETosis with the participation of the PI3K/Akt/PBK pathway in patients with OSCC.

Profile of new vascular damage biomarkers in middle-aged men with arterial hypertension

PURPOSE

Normal endothelial function is important for the homeostasis of the cardiovascular (CV) system. The aim of the present study was to determine the profile of key parameters of endothelial dysfunction in middle-aged men that play a significant role in the functioning of endothelial vessels, which seems to be crucial for the early diagnosis of cardiovascular disorders.

MATERIALS AND METHODS

The study included 53 men, 20 with hypertension (HTN), 18 with HTN and related diseases, 15 healthy controls Apart from general testing (BMI, biochemical analysis, SBP, DBP), we used the Griess reaction to assess the total amount of nitric oxide (NO), and used ELISA to verify the concentrations of malondialdehyde (MDA), nitrotyrosine (NT), asymmetric dimethylarginine (ADMA), tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1), and myeloperoxidase (MPO). Furthermore, we assessed the concentration of circulating free DNA (cfDNA) using the fluorescence method.

RESULTS

The values of MDA, ADMA, cfDNA, and MPO observed in samples from men with HTN were determined to be higher compared to those from men without HTN. In the group of men with HTN and other concomitant cardiovascular disorders, we observed low concentrations of NO, MDA, and ADMA with high concentrations of cfDNA.

CONCLUSIONS

The results obtained for parameters selected for the study, should be considered by cardiologists as a prompt to include in the diagnostic profile the assessment of NO and cfDNA concentrations for risk evaluation and/or diagnosis of endothelial dysfunction in patients suffering from HTN or related complications.

Significance of NETs Formation in COVID-19

Severe contagious respiratory disease—COVID-19—caused by the SARS-CoV-2 coronavirus, can lead to fatal respiratory failure associated with an excessive inflammatory response. Infiltration and spread of SARS-CoV-2 are based on the interaction between the virus’ structural protein S and the cell’s receptor–angiotensin-converting enzyme 2 (ACE2), with the simultaneous involvement of human trans-membrane protease, serine 2 (TMPRSS2). Many scientific reports stress the importance of elevated recruitment and activity of neutrophils, which can form extracellular neutrophil traps (NETs) playing a significant role in the mechanism of combating pathogens, in the pathogenesis of COVID-19. Excessive generation of NETs during prolonged periods of inflammation predisposes for the occurrence of undesirable reactions including thromboembolic complications and damage to surrounding tissues and organs. Within the present manuscript, we draw attention to the impact of NET generation on the severe course of COVID-19 in patients with concurrent cardiovascular and metabolic diseases. Additionally, we indicate the necessity to explore not only the cellular but also the molecular bases of COVID-19 pathogenesis, which may aid the development of dedicated therapies meant to improve chances for the successful treatment of patients. We also present new directions of research into medications that display NETs formation regulatory properties as potential significant therapeutic strategies in the progress of COVID-19.

Sex-dependent dysregulation of human neutrophil responses by bisphenol A

BACKGROUND

In the present study, we aimed to investigate selected functions of human neutrophils exposed to bisphenol A (BPA) under in vitro conditions. As BPA is classified among xenoestrogens, we compared its action and effects with those of 17β-estradiol (E2).

METHODS

Chemotaxis of neutrophils was examined using the Boyden chamber. Their phagocytosis and nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase activity were assessed via Park's method with latex beads and Park's test with nitroblue tetrazolium. To assess the total concentration of nitric oxide (NO), the Griess reaction was utilized. Flow cytometry was used to assess the expression of cluster of differentiation (CD) antigens. The formation of neutrophil extracellular traps (NETs) was analyzed using a microscope (IN Cell Analyzer 2200 system). Expression of the investigated proteins was determined using Western blot.

RESULTS

The analysis of results obtained for both sexes demonstrated that after exposure to BPA, the chemotactic capacity of neutrophils was reduced. In the presence of BPA, the phagocytic activity was found to be elevated in the cells obtained from women and reduced in the cells from men. Following exposure to BPA, the percentage of neutrophils with CD14 and CD284 (TLR4) expression, as well as the percentage of cells forming NETs, was increased in the cells from both sexes. The stimulatory role of BPA and E2 in the activation of NADPH oxidase was observed only in female cells. On the other hand, no influence of E2 on the expression of CD14 and CD284, chemotaxis, phagocytosis, and the amount of NET-positive neutrophils was found for both sexes. The study further showed that BPA intensified NO production and iNOS expression in the cells of both sexes. In addition, intensified expression of all tested PI3K-Akt pathway proteins was observed in male neutrophils.

CONCLUSIONS

The study demonstrated the influence of BPA on neutrophil functions associated with locomotion and pathogen elimination, which in turn may disturb the immune response of these cells in both women and men. Analysis of the obtained data showed that the effect of this xenoestrogen on the human neutrophils was more pronounced than E2.

A Proliferation-Inducing Ligand Regulation in Polymorphonuclear Neutrophils by Panax ginseng

A proliferation-inducing ligand (APRIL) is a member of the tumor necrosis factor superfamily that was first identified as a factor favoring tumorigenesis. APRIL is important fitness and survival factors for B cells and plasma cells in the periphery. Considering this, as well as the quantitative predominance of neutrophils among the peripheral blood leukocytes, we carried out the first study assessing the influence of the transforming growth factor (TGF)-β signaling pathway on APRIL expression in these cells. Furthermore, as the Rb1 ginsenoside is known to exhibit multiple pharmacological activities, we verified if the saponin is capable of modulating the process. The present study shows that TGF-β increased the expression of APRIL and the level of phospho-p38, phospho-Akt(T308), and phospho-Akt(S473) in the cytoplasmic fraction, as well as the expression of Fra1, c-Fos, and c-Jun in the nuclear fraction, of neutrophils. However, exposure of these cells to Rb1 reduced the expression and level of the investigated proteins. No changes were found in the expression of APRIL and the level of p-p38 in the cytoplasmic fraction of neutrophils following the application of Rb1 alone, as well as in the neutrophils incubated first with Rb1 and then with TGF-β, whereas a higher level of phosphorylation was observed for Akt and PI3 kinases in the cells. Moreover, a higher expression of all the studied transcription factors was observed in the nuclear fraction of neutrophils. Based on the observed changes, it may be assumed that the expression of APRIL molecule in TGF-β-induced neutrophils and its regulation by Rb1 are associated with PI3K/AKT signaling pathways and transcription factors Fra-1, Fra-2, c-Jun, and c-Fos. Rb1 appears to be a favorable factor that may be potentially used in the modulation of tumor-promoting APRIL expression.

LDGs versus NDGs in patients with oral squamous cell carcinoma (OSCC)

BACKGROUND

The significant role played by neutrophils in cancer biology is indisputable; yet, their subpopulations may exhibit a contrasting role. The phenomenon of polarization of neutrophils and signaling modulators in the course of a neoplastic process has gained increased attention in recent times. The present study's objective was to quantitatively assess low-density neutrophils (LDNs) and normal-density neutrophils (NDNs) populations including IL-17 expression in confrontation with Th17 lymphocytes in patients with oral squamous cell carcinoma (OSCC). The neutrophil to lymphocyte ratio (NLR) biomarker value was determined. Besides, the influence of rhIL-17 on the proliferation level of the squamous cell carcinoma (SCC) malignant line cells was tested.

METHODS

Leukocytes were isolated in the density gradient and the CD16+ population was magnetically sorted. The percentages of neutrophil subpopulations, lymphocyte Th17, and IL-17 expression in the studied cells were determined on a flow cytometer. Squamous cell carcinoma proliferation was assessed with the MTT test.

RESULT

The existence of two populations of human neutrophils was determined: LDNs and NDNs. A higher percentage of LDNs and Th17 was observed with the concomitant lower percentage of NDNs in patients with OSCC as compared with the control group. NLR was elevated in patients with cancer. The highest IL-17 expression was obtained in the LDNs population in these patients. However, no influence of IL-17 on SCC proliferation could be determined.

CONCLUSION

The present study demonstrated a strong relationship between IL-17 concentration and the count of LDNs or Th17 in the course of OSCC, which may serve as a reference point for new therapies. Moreover, the obtained LDNs/NDNs and NLR values in patients with cancer prove their usefulness in diagnostic and prognostic in patients with OSCC.

Neutrophil extracellular traps (NETs) formation induced by TGF-β in oral lichen planus - Possible implications for the development of oral cancer

Oral Potentially Malignant Disorders (OPMDs) including Oral Lichen Planus (OLP) are associated with risk of transformation to oral squamous cell carcinoma (OSCC). Available data show that innate immune cells involving polymorphonuclear neutrophils (PMNs) with their ability to neutrophil extracellular traps (NETs) formation are likely to be directly involved in development of cancer. Examination of NETs generation by TGF-β - induced neutrophils of OLP patients showed increased amounts of traps with MPO, H3Cit and cfDNA, known to be released with NETs. The presence of excessive amounts of NETs components may lead to numerous adverse consequences associated with potential transformation to OSCC. Bacterial-related infection may enhance the NETs formation and lead to consequences resulting from the excessive number of individual elements of these networks. It is likely that regulating NETs release by the flavonoids presented herein may be beneficial not only for inhibiting OLP development, but also in reducing risk of transformation to OSCC.

Expression of serine proteases in neutrophils from women and men: Regulation by endocrine disruptor bisphenol A

Bisphenol A (BPA) is a well-known endocrine disruptor. However, little information is available about its immunological effects. In the present study, we aimed to evaluate cytotoxic activity of BPA on human polymorphonuclear neutrophils (PMNs) according to gender and examine its effect on the expression of neutrophil serine proteases. Results indicated that exposure to BPA (above 16 μM) leads to a decrease in viability of PMNs and to morphological changes in these cells of both genders. The experiments showed different effects of BPA on the expression of proteinase 3, elastase, and cathepsin G in PMNs of both men and women, depending on the gender and concentration used. Thus, our findings suggest for the first time that through dysregulation of the expression of these enzymes, BPA may lead to disorders of the nonspecific cellular response in people exposed to this xenoestrogen.

N-nitrosodimethylamine (NDMA) induced apoptosis dependent on Fas/FasL complex in human leukocytes

Objective:

To investigate the mechanism of apoptosis dependent on the Fas/FasL (Fas ligand) complex in the presence of N-nitrosodimethylamine (NDMA) in human leukocytes.

Methods:

Polymorphonuclear neutrophils (PMNs) and peripheral blood mononuclear cells (PBMCs) were isolated form whole blood by density centrifugation. The concentration of NDMA was assessed by cellular toxicity assay. Apoptotic cells were assessed with flow cytometry and the expression of pro- and antiapoptotic proteins was investigated by Western blotting in PMNs and PBMCs treated with NDMA and/or FasL.

Results:

PMNs showed a higher ratio of apoptotic cells than PBMCs after exposure to NDMA and/or FasL. Enhanced apoptosis was related to the increased expression of proapoptotic proteins in neutrophils following exposure to either NDMA or FasL. In PBMCs, the relation was observed after exposure to FasL only. PMNs and PBMCs incubated with NDMA and FasL simultaneously demonstrated the highest increase in protein expression.

Conclusions:

NDMA shows a stronger proapoptotic effect with PMNs than with PBMCs. The Fas/FasL complex, along with other proapoptotic proteins of the receptor (Fas, FADD) and mitochondrial pathway (Noxa, Puma, Bim), plays a key role in the induction of neutrophil apoptosis. Synergic effects of NDMA and FasL which lead to higher induction of apoptosis in PMNs than in PBMCs indicates a multistage and varied regulation of apoptosis in different populations of leukocytes.

Many Ways-One Destination: Different Types of Neutrophils Death

Neutrophils constitute the most numerous populations of peripheral blood leukocytes, fulfilling the fundamental role in the development of the innate immune response. As the cells of the first line of defense, they guard the organism against the spread of pathogenic microorganisms. Neutrophils, similar to the other cells of the immune system, enter the path of death after fulfilling their biological function. Depending on the conditions that they are found in, they may undergo different types of cell death which requires the involvement of numerous signaling pathways. In this review article, we summarize the current state of knowledge regarding the different forms of neutrophil death, such as apoptosis, necrosis, necroptosis, autophagy, NETosis and pyroptosis.

Bone Metabolism Markers and Bone Mineral Density in Patients on Long-Term Acenocoumarol Treatment: A Cross-Sectional Study

The aim of this study was to evaluate levels of osteocalcin (OC), osteoprotegerin (OPG) and total soluble receptor activator of nuclear factor-κB ligand (RANKL), and bone mineral density (BMD) in patients on long-term acenocoumarol (AC) treatment. The cross-sectional study was carried out in 42 patients treated long-term with AC and 28 control subjects. Serum concentrations of OC, OPG, and sRANKL were measured using enzyme linked immunosorbent assay (ELISA) kits, and BMD at the femoral neck and lumbar spine were assessed by dual energy X-ray absorptiometry. A significantly decreased concentration of OC was found in AC users compared to control subjects (4.94 ± 2.22 vs. 10.68 ± 4.5; p < 0.001). Levels of OPG, sRANKL logarithm (log), sRANKL/OPG log ratio, and BMD were comparable between. In female AC users, positive correlations between OC and RANKL log, and between OC and RANKL/OPG log ratio (p = 0.017; p = 0.005, respectively), and a negative correlation between OC and OPG (p = 0.027) were found. Long-term AC anticoagulation significantly decreases OC concentration, but does not affect other bone metabolism markers or BMD. Our results also suggest the possibility that long-term treatment with AC may alleviate bone resorption in postmenopausal women.

Sex-specific differences in the regulation of inducible nitric oxide synthase by bisphenol A in neutrophils

The aim of the study was to evaluate the effect of bisphenol A (BPA) on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression by neutrophils with regard to sex and nuclear factor-κB (NF-κB) pathway participation in this process. This study demonstrated that BPA intensifies the production of NO and the expression of iNOS in the cytoplasmic fraction of neutrophils of women as well as men. In addition, an enhanced expression of NF-κB in the cytoplasmic and nuclear fraction of neutrophils exposed to BPA was observed in the cells of both sexes. The lipopolysaccharide (LPS) stimulation of neutrophils of both sexes led to an intensification of NO production and expression of all tested proteins. However, simultaneous stimulation of neutrophils of both men and women with LPS and BPA decreased the production of NO and expression of iNOS and NF-κB in both fractions compared to the cells exposed only to xenoestrogen. Moreover, expression of iNOS and NF-κB was higher in female neutrophils than in male cells. This study demonstrated that BPA affects the production of NO with the participation of iNOS by human polymorphonuclear neutrophils. This process is associated with the activation of the NF-κB pathway. In addition, different activity of NF-κB in neutrophils, observed with respect to sex, indicates a different role of this pathway in female and male cells.

The Phenomenon of Neutrophil Extracellular Traps in Vascular Diseases

Vascular diseases constitute a global health issue due to the increasing number of cases of patients with these diseases. The pathogenesis of the majority of these diseases, including atherosclerosis and thrombosis, is complex and not yet fully understood. One of the major causes for their occurrence can be immune disorders resulting in the development of a chronic inflammation within the vessels. In recent years, studies have placed emphasis on the role of neutrophils in the development of these diseases, i.e., the discovery of neutrophil extracellular traps (NETs) demonstrated that the structures released by the cells may contribute to the enhancement of inflammatory reactions and cell damage. This article summarizes current knowledge on the role of NETs during atherosclerosis, thrombosis and small-vessel vasculitis, especially in antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitis (AAV).

Differences and similarities in the phenomenon of NETs formation in oral inflammation and in oral squamous cell carcinoma

Taking into account the previously reported relationship between inflammation and carcinogenesis, and the scant amount of data concerning the role of neutrophil extracellular traps (NETs) in carcinogenesis, we decided to study the process of extracellular trap formation in patients with inflammation as well as in patients with cancer occurring in the same location. For preliminary isolation of neutrophils (PMNs), we used Polymorphprep™, then sorted with Microbeads. The cells were recorded in the incubation chamber with a BD Pathway 855 microscope system. Flow cytometric data (MPO+ neutrophils) were acquired on FACSCalibur flow cytometer. Amounts of cfDNA were determined by Abcam's Circulating DNA Quantification Kit. Neutrophils of patients with inflammation and of subjects with stage I/II oral squamous cell carcinoma (OSCC) produce increased amounts of NETs, while stage III/IV OSCC were comparable with the control group. In all of the studied groups of cells stimulation with LPS and rhIL-17 produced more NETs in relation to unstimulated cells. Neutrophil supernatant of inflammation patients and stage I/II cancer patients demonstrated the increased level of cfDNA, which decreased at stage III/IV. Patients with oral inflammations showed an increased rate of MPO+ neutrophils, which was lower than in stage I/II cancer patients and not significantly different than in Stage III/IV cancer patients and the control group. The direction of changes in NETs formation seems to be a new common element shared by inflammation and early stage cancer. Changes in the formation of NETs observed in patients with advanced cancer, other than an early phase or inflammation, indicate an alternative range of NETs involvement depending on different phases of this disease.

The effect of omeprazole treatment on the gut microflora and neutrophil function

BACKGROUND AND AIM

Proton pump inhibitors (PPIs) may increase the risk of Clostridium difficile infections. There are interactions between gut microbiota and innate immune cells including neutrophils. We evaluated the effect of treatment with omeprazole on the gut microflora and neutrophil function.

METHODS

In 50 patients, we evaluated the effect of 4-week omeprazole treatment (n=25 with 20mg per day and n=25 with 20mg twice daily) on intragastric pH, results of stool culture and lactulose hydrogen breath test (LHBT) and neutrophil function.

RESULTS

The treatment caused significant increase of the mean intragastric pH, especially in the group with 20mg omeprazole twice daily (from 2.05±0.59 to 5.06±1.6, P<0.001). In LHBT, the increase of hydrogen concentration was observed in higher percentage of patients with 20mg of omeprazole twice daily, compared to patients with the lower dose (42.1% vs 29.4%; ns). Four weeks of omeprazole treatment have caused considerable changes in stool culture results. Patients treated with higher dose of omeprazole have had some tendency to decrease diversity of colonic microflora in comparison with patients treated with the lower dose of omeprazole. Treatment with omeprazole did not result in C. difficile positive stool culture and had no significant effect on neutrophil function.

CONCLUSIONS

Omeprazole treatment have caused considerable changes in stool culture results. Patients treated with the higher dose had some tendency to decreased diversity of colonic microflora and towards changes in fermenting bacteria of the gut. The potential effect of omeprazole on gut microflora does not depend on neutrophil function deterioration.

Heterogeneity Among Neutrophils

Neutrophils (PMNs) play a key role in innate defence mechanisms. Generally, PMNs were considered to have a homogeneous population of mature and diversified cells. It seems, however, that their pleiotropic action results from the existence of different subpopulations in this group of cells. There are data that confirm the involvement of PMNs in the direct activation of other cells in non-specific response, as well as specialised cells in specific response. For example, there have been observations of PMNs with different levels of activity in relation to lymphocytes, and a population was identified which had characteristics similar to those of cells which are capable of presenting antigens. There are also reports of PMNs which demonstrate different survival time or capacity for chemotaxis. Other studies suggest that the neutrophil response to Staphylococcus aureus is diverse (not identical among all neutrophil). There are also reports of PMNs with varying activity during inflammation, which might explain many as yet unknown pathophysiological aspects of their hyperreactivity. The functional dualism of PMNs in the course of neoplastic disorders raises a lot of controversy. This paper presents the current state of knowledge of the heterogeneity of PMNs and their potential roles in different stages of disease.

New Aspects of the Biology of Neutrophil Extracellular Traps

The formation and release of neutrophil extracellular traps (NETs) discovered in 2004 by Volker Brinkmann and Arturo Zychlinsky cast a new light on the role of neutrophils in the non-specific immune response of the body. This discovery has resulted in the rapid development of neutrophil studies in different bacterial and autoimmune diseases as well as neoplasms. Research is also being performed on the role of different signalling pathways engaged in the induction of NETosis, a unique form of a programmed cell death leading to the creation of NETs. The literature provides information on the structure and composition of neutrophil extracellular traps. This review presents the latest data on NET formation and the role of their key components, as well as describing the intracellular signalling pathways leading to the generation of NETs that have been discovered.

The effect of short-term oral treatment with omeprazole or pantoprazole on the function of polymorphonuclear neutrophils

Recent studies report an increased risk of enteric infections in patients treated with proton pump inhibitors (PPIs). Polymorphonuclear neutrophils (PMNs) play a key role in host response to bacterial infection. We evaluated the effect of omeprazole and pantoprazole treatment on the PMN function. Fifteen patients were treated with omeprazole 20 mg daily and 15 patients with pantoprazole 40 mg daily for 7 days. Treatment with omeprazole or pantoprazole had no effect on spontaneous nitroblue tetrazolium (NBT) test results. Significant increase in the percentage of phagocytes in the omeprazole group in stimulated NBT test (by 69%) was found. Treatment with omeprazole or pantoprazole had no effect on nitric oxide (NO) concentration in the PMN culture supernatant and serum, cyclic guanosine monophosphate concentration in the PMN culture supernatant and serum, as well as inducible nitric oxide synthase (iNOS) protein expression and p38 mitogen-activated protein kinase activity in PMNs. In conclusion, treatment with PPI has no effect on NO production and p38 mitogen-activated protein kinase activity in PMNs. Interestingly, short-term treatment with omeprazole but not with pantoprazole enhances PMN reactive oxygen species production.

Cytokine Network & NETs

The process of forming and releasing neutrophil extracellular traps (NETs) can be regulated by exogenous and endogenous factors, including cytokines. The study aimed to assess the impact of proinflammatory cytokines, IL-15, IL-17, IL-18, and anti-inflammatory IL-10 on the formation of NETs, all in comparison to IL-8 and pathogenic factors: LPS, fMLP. Also, the expression of myeloperoxidase (MPO), one of the main elements of neutrophil traps, was evaluated. After isolating the neutrophils with Polymorphprep™, the cells were sorted using CD16 MACS® microbeads and incubated with selected factors. The formation of NETs was registered using a BD Pathway 855 microscope system and the expression of MPO was evaluated using flow cytometry. The amounts of circulating DNA in cell supernatants was fluorescently quantified. Microscopic photographs indicated that rhIL-15, rhIL-17, rhIL-18 and fMLP induce formation and release of NETs at a similar timespan, while in the presence of rhIL-10, the formation of the traps was delayed. The presence of the studied cytokines indicated two populations of neutrophils displaying differing MPO expression (MPOlow and MPOhigh). Moreover, stimulation of neutrophils with LPS and fMLP revealed two populations of these cells that differed not only in the expression of MPO, but also in size.

Expression of IL-1 and IL-6 and their natural regulators in leukocytes of B-cell chronic lymphocytic leukaemia patients

PURPOSE

The purpose of the study was the assessment of the expression of IL-1β and IL-6, and the proteins regulating their biological activity, namely IL-1RII, IL-1Ra, as well as sIL-6Rα, sgp-130 in leukemic lymphocytes and autologous neutrophils of B-CLL patients.

MATERIAL/METHODS

The study involved a group of B-cell chronic lymphocytic leukemia patients and healthy volunteer blood donors. The presence of chosen proteins and their natural regulators was confirmed by Western blot.

RESULTS

Western blot analysis showed a decreased expression of IL-1β and IL-6 in the leukocytes of B-CLL patients. Decreased expression of sIL-6Rα has been observed in lymphocytes, with a simultaneous increase of expression in PMNs. Lower expression of sgp-130 was found in B cells while its expression was elevated in the neutrophils of patients in early stages of the disease.

CONCLUSIONS

The changes observed in the expression of IL-1 and IL-6 seem to exclude their immediate involvement in the progress of B-CLL. However, the presented changes in the expression of proteins regulating IL-1β and IL-6 in PMNs indicate a potential role of early immune response cells also in advanced stages of the disease.

Expression of subtypes of interleukin-17 ligands and receptors in patients with B-cell chronic lymphocytic leukemia

BACKGROUND

The diversity of biological effects of cytokines from the IL-17 family, as well as the wide range of cells sensitive to their influence, suggests that these molecules might play a significant role in the malignant pro- cess.

METHODS

After the cells were initially isolated with Polymorphprep™, they were sorted with a MACS® magnetic separator, CD16 for neutrophils and CD19 for B lymphocytes. The presence of proteins: IL-17A, IL-17E, IL-17F, IL-17D, as well as receptors: IL-17R, IL-17BR, IL-17RC in cell lysates was confirmed by Western blot. The levels of IL-17A, IL-17E, and IL-17F in blood serum were determined with ELISA.

RESULTS

The results indicate a lower expression of IL-17A, IL-17E, and IL-17F in PMNs and B lymphocytes of pa- tients with B-cell chronic lymphocytic leukemia compared to cells of healthy subjects. Elevated expression of IL- 17D was observed in the PMNs of patients, with a simultaneous decrease in the expression of this cytokine in leukemic B cells, in comparison to the control group. In patients with B-CLL, there also were observations of decreased expression of IL-17R, IL-17BR, and IL-17RC in leukemic B lymphocytes, compared to their expressions in the cells of healthy subjects. The blood serum of B-CLL patients demonstrated a significantly increased level of IL-17A at stage 0/I, II, and IV of disease; IL-17E at stage 0/I and II; IL-17F at stage 0/I, III, and IV of disease advancement, compared to the data obtained from the control group.

CONCLUSIONS

The results clearly support the involvement of the studied proteins from the IL-17 family in the course of B-CLL and indicate that IL-17D may play a significant role in the course of this disease.

TNF superfamily proteins in the serum of patients with B-ALL--preliminary study

BACKGROUND

TNF superfamily ligands such as B cell-activating factor (BAFF), a proliferation inducing ligand (APRIL) and TNF-related apoptosis inducing ligand (TRAIL), can play an important role in the pathogenesis and development of various B cell malignancies involving B-ALL.

METHODS

The study group consisted of 25 children suffering from newly diagnosed B cell precursor ALL (B- ALL), involving immunophenotype pre-B and common-cALL. Peripheral blood samples were collected at the time of diagnosis, before any treatment, and after treatment. Soluble APRIL, soluble BAFF, and soluble TRAIL concentrations were assessed using ELISA kits.

RESULTS

The concentrations of sAPRIL and sBAFF in the sera of the patient group were higher compared to the values of the control specimens. Among all molecules examined, the highest concentrations were found for the sAPRIL molecule. Furthermore, sAPRIL and sBAFF concentrations were higher in patients with ALL-pre B than in patients with cALL. After the treatment, the sera of patients with ALL-pre B contained lower concentrations of sAPRIL, sBAFF, and sTRAIL than those of the same patients before therapy.

CONCLUSIONS

Contrary to earlier indications of the key function of BAFF in B-ALL, the quantitative dominance of APRIL in the serum suggests that this molecule can play an equivalent or even more significant role in this patient group than BAFF.

Expression of selected proteins of the extrinsic and intrinsic pathways of apoptosis in human leukocytes exposed to N-nitrosodimethylamine

N-nitrosodimethylamine (NDMA) is a xenobiotic widespread in human environment capable of regulating the lifespan of immune cells. In this study, we examined the roles of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/death receptor 5 (DR5) complex and the Fas molecule in the induction of the extrinsic apoptosis pathway in human neutrophils (polymorphonuclear neutrophils (PMNs)) and peripheral blood mononuclear cells (PBMCs) exposed to NDMA. Also we assessed these proteins ability to trigger the intrinsic apoptosis pathway in those cells. For this purpose, we examined the expression of Fas-associated protein with death domain, truncated Bid (tBid) proteins, and apoptogenic factors such as apoptosis-inducing factor, Smac/Diablo, Omi/HtrA2, and caspase-3 as an indication of accomplished apoptosis phenomenon. PMNs and PBMCs were isolated from whole blood by density gradient centrifugation using Polymorphrep. Apoptotic cells were assessed with flow cytometry using a ready-made kit. The expression of proapoptotic molecules was investigated by Western blot analysis of PMNs and PBMCs treated with NDMA and/or rhTRAIL. The obtained results confirm the proapoptotic effects of NDMA on the examined human leukocytes and indicate an active participation of the TRAIL/DR5 complex and Fas protein in the process of apoptosis. Moreover, the research revealed distinct mechanisms of intrinsic apoptosis pathway activation between PMNs and PBMCs exposed to NDMA, as confirmed by the different levels of tBid, Smac/Diablo, Omi/HtrA2, and caspase-3 expression in those cells.

PI3K-Akt/PKB signaling pathway in neutrophils and mononuclear cells exposed to N-nitrosodimethylamine

Neutrophils (PMN) play diverse regulatory and effector functions in the immune system through the release of reactive nitrogen species, including nitric oxide (NO). The enzyme responsible for NO synthesis in PMN is inducible nitric oxide synthase (iNOS) that is regulated by various signaling pathways, e.g. PI3K-Akt/PKB, and transcription factors. N-Nitrosodimethylamine (NDMA), a xenobiotic widespread in the human environment, affects immune cells. The study objective here was to examine the role of the PI3K-Akt/PKB pathway in induction of NO synthesis (with involvement of iNOS) in human PMN, as well as in autologous mononuclear cells (PBMC), exposed to NDMA. Isolated cells were incubated for 2 h with a sub-lethal dose of NDMA and then the expression of several select proteins in the cell cytoplasmic and nuclear fractions were determined by Western blot analyses. The results indicated that NDMA enhanced expression of iNOS, phospho-PI3K, and phospho-IκBα in the cytoplasmic fraction of the PMN and PBMC. The nuclear fraction of these cells also had a higher NF-κB expression. Moreover, in PMN, NDMA caused an increased expression of phospho-Akt (T308), phospho-Akt (S473), and phospho-IKKαβ in the cytoplasm, and c-Jun and FosB in the nuclear fraction. Blocking of PI3K caused a decrease in expression of all these proteins in NDMA-exposed PMN. However, inhibition of PI3K led to a drop in expression of iNOS, phospho-PI3K, and phospho-IκBα in the cytoplasm, and in NF-κB in the nuclear fraction, of PBMC. The results of these studies indicated to us that NDMA activates the PI3K-Akt/PKB pathway in human PMN and that this, in turn, contributes to the activation of transcription factors NF-κB, c-Jun, and FosB involved in NO production (through modulation of iNOS expression).

Role of ERK1/2 kinase in the expression of iNOS by NDMA in human neutrophils

Potential role of ERK1/2 kinase in conjunction with p38 in the regulation of inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production, and superoxide anion generation by human neutrophils (PMNs) exposed to N-nitrosodimethylamine (NDMA) was determined. Increased synthesis of NO due to the involvement of iNOS in neutrophils exposed to NDMA was observed. In addition, intensified activation of ERK1/2 and p38 kinases was determined in these cells. Inhibition of kinase regulated by extracellular signals (ERK1/2) pathway, in contrast to p38 pathway, led to an increased production of NO and expression of iNOS in PMNs. Moreover, as a result of inhibition of ERK1/2 pathway, a decreased activation of p38 kinase was observed in neutrophils, while inhibition of p38 kinase did not affect activation of ERK1/2 pathway in these cells. An increased ability to release superoxide anion by the studied PMNs was observed, which decreased after ERK1/2 pathway inhibition. In conclusion, in human neutrophils, ERK1/2 kinase is not directly involved in the regulation of iNOS and NO production induced by NDMA; however, the kinase participates in superoxide anion production in these cells.

TLR4 ligation induces expression of APRIL molecule in human neutrophils - a preliminary study

In the present study we investigate the consequences of TLR4 activation by LPS for the synthesis of a proliferation-inducing ligand (APRIL) by human neutrophils (PMNs), and the possible role of the ERK1/2 kinases signaling pathway. In order to make a comparison, the same examinations were carried out on autologous peripheral blood mononuclear cells (PBMCs). The levels of mRNA for APRIL and TLR4 were measured using the real-time PCR method. Western blot analysis was used to assay the expressions of APRIL and ERK1/2 in cell lysates. We discovered an increased expression of APRIL accompanying the increased expression of TLR4 in the LPS-stimulated PMNs and PBMCs. Furthermore, stimulation with LPS triggered similar changes in phospho-ERK1/2 proteins expression in those cells. The present study suggests that LPS plays a role in TLR4-ligation in APRIL induction through ERK1/2 pathway activation in human neutrophils and mononuclear cells of peripheral blood. The association between TLR4 activation and APRIL expression in examined leukocytes might have important implications for the immune response of the host exposed to TLR4 ligands such as LPS.

Role of AP-1 family proteins in regulation of inducible nitric oxide synthase (iNOS) in human neutrophils

The aim of the study was to assess the activity of AP-1 family proteins, e.g. Fra-1, Fra-2, JunB, JunD, and FosB, engaged in the regulation of inducible nitric oxide synthase (iNOS) expression and the production of NO by neutrophils (PMN) exposed to N-nitrosodimethylamine (NDMA) xenobiotic. Isolated human PMN were incubated in the presence of NDMA. iNOS mRNA expression was then analyzed using Northern blot and the expression of other proteins in the cytoplasmic and nuclear fractions were assessed using Western blot. The obtained results indicate that NDMA increased iNOS mRNA and protein expression in human PMN. Furthermore, it increased the expression of Fra-1, Fra-2, JunB, and JunD in the cytoplasmic fraction, and FosB expression in the fractions of analyzed cells. As a consequence of inhibiting p38 pathway and JNK, reduced iNOS expression and NO production was noted in PMN exposed to NDMA. Inhibition of the p38 pathway resulted in reduced expression of all analyzed proteins in the cytoplasmic fraction of PMN exposed to NDMA. Furthermore, increased Fra-2 expression and reduced FosB expression were found in the nuclear fraction of those cells. Inhibiting ERK5 pathway resulted in increased JunB expression in both fractions of the analyzed cells. Therefore, no changes in the expression of analyzed proteins in the presence of NDMA were observed in PMN pre-incubated with JNK pathway inhibitor. In conclusion, the results here indicate a role of Fra-1, Fra-2, JunB, JunD, and FosB transcription factors in the regulation of iNOS expression and NO production by human neutrophils exposed to NDMA.