The Role of NOX2-Derived Reactive Oxygen Species in the Induction of Endothelin-Converting Enzyme-1 by Angiotensin II

Endothelin-1 is a key regulator of vascular tone and blood pressure in health and disease. We have recently found that ET-1 production in human microvascular endothelial cells (HMECs) can be promoted by angiotensin II (Ang II) through a novel mechanism involving octamer-binding transcription factor-1 (Oct-1), NADPH oxidase-2 (NOX2), and superoxide anions. As the formation of bioactive ET-1 also depends on endothelin-converting enzyme-1 (ECE-1), we investigated the transcriptional regulation of the ECE1 gene. We found that exposure of HMECs to Ang II resulted in a concentration- and time-dependent increase in ECE1 mRNA expression. Pharmacological inhibition of ECE-1 reduced Ang II-stimulated ET-1 release to baseline values. The effect of Ang II on ECE1 mRNA expression was associated with Oct-1 binding to the ECE1 promoter, resulting in its increased activity. Consequently, the Ang II-stimulated increase in ECE1 mRNA expression could be prevented by siRNA-mediated Oct-1 inhibition. It could also be abolished by silencing the NOX2 gene and neutralizing superoxide anions with superoxide dismutase. In mice fed a high-fat diet, cardiac expression of Ece1 mRNA increased in wild-type mice but not in Nox2-deficient animals. It can be concluded that Ang II engages Oct-1, NOX2, and superoxide anions to stimulate ECE1 expression in the endothelium.

Treatment regimens and disease activity could alter salivary myeloperoxidase levels in patients with inflammatory bowel diseases

INTRODUCTION

Inflammatory bowel diseases (IBDs) present with alternating periods of exacerbation and remission; therefore, it is necessary to develop noninvasive diagnostic tools to control the disease activity and improve therapeutic effectiveness. Recently, we have found that patients with ulcerative colitis (UC) who qualified for biologic therapy had significantly lower salivary myeloperoxidase (MPO) levels.

OBJECTIVES

This cross‑sectional study aimed to assess the impact of IBD activity and applied treatment on salivary antioxidant system as reflected by the levels of catalase, total antioxidant status, and MPO.

PATIENTS AND METHODS

The study group comprised 99 patients diagnosed with Crohn disease (CD) and 61 patients with UC. The Crohn Disease Activity Index and modified Mayo scale were used to estimate the clinical activity of CD and UC, respectively. Unstimulated whole mixed saliva was collected. Salivary levels of selected markers were measured with enzyme‑linked immunosorbent assays and colorimetric assays.

RESULTS

The patients with clinically active UC showed significantly decreased median (interquartile range) salivary MPO levels (79.4 [30.1-157.5] vs 94.8 [58.2-274.7] ng/ml) with significant correlations with the endoscopic stage on the Mayo scale (R = 0.423; P = 0.02). Receiver operating characteristic analysis confirmed a potential usefulness of MPO concentrations in predicting clinically active UC (area under the curve = 0.654; P = 0.03; cutoff <210.4 ng/ml). Moreover, in the patients treated with biologics and without steroid therapy, salivary MPO concentrations negatively correlated with neutrophil counts in the individuals with UC and positively with C‑reactive protein level in the patients with CD.

CONCLUSIONS

Salivary MPO levels changed depending on the disease activity in the patients with UC. Decreased MPO concentration in the saliva could be a predictor of clinically active UC.

Seasonal Influence on Salivary Myeloperoxidase Diurnal Variations in Young Healthy Subjects: A Preliminary Study

BACKGROUND

The interaction between oxidative status markers and biological rhythms is considered particularly important in the pathogenesis of many diseases and more effective therapies. We aimed to determine if the salivary secretion of myeloperoxidase exhibits diurnal variations, and if the potential daily variability differs seasonally.

METHODS

The study was performed in Poznan, Poland (52,25°N, 16,58°E) in 10 healthy male volunteers (age median 23.5 years). Whole mixed unstimulated saliva was collected in summer (August) and winter (December) during 36 h at 2-h intervals starting at 6 a.m. on Saturday and ending at 6 p.m. on Sunday, in the domestic setting. The samples were analysed for myeloperoxidase (MPO) and cortisol by immunoassays. The presence of the circadian rhythm of cortisol secretion in saliva confirmed the rhythmicity of the volunteers.

RESULTS

For salivary MPO, significantly higher concentrations compared to midnight and noon were observed for 4 a.m. in both summer and winter. Using the cosinor analysis, the variations in salivary MPO levels showed a moderate fit for the 12-h period rhythm (acrophases: in summer 05:37/17:37, in winter 06:16/18:16), without significant differences in the rhythm parameters in summer and winter. However, higher self-reported Global Seasonal Score (which may predispose to seasonal affective disorder) was associated with significantly stronger relative amplitude (RS = 0.811) in winter season only.

CONCLUSIONS

In conclusion, our findings suggest the possible ultradian rhythm for MPO in saliva, with two peaks during the day, regardless of the season.

Autoantibodies from patients with kidney allograft vasculopathy stimulate a proinflammatory switch in endothelial cells and monocytes mediated via GPCR-directed PAR1-TNF-α signaling

Non-HLA-directed regulatory autoantibodies (RABs) are known to target G-protein coupled receptors (GPCRs) and thereby contribute to kidney transplant vasculopathy and failure. However, the detailed underlying signaling mechanisms in human microvascular endothelial cells (HMECs) and immune cells need to be clarified in more detail. In this study, we compared the immune stimulatory effects and concomitant intracellular and extracellular signaling mechanisms of immunoglobulin G (IgG)-fractions from kidney transplant patients with allograft vasculopathy (KTx-IgG), to that from patients without vasculopathy, or matched healthy controls (Con-IgG). We found that KTx-IgG from patients with vasculopathy, but not KTx-IgG from patients without vasculopathy or Con-IgG, elicits HMEC activation and subsequent upregulation and secretion of tumor necrosis factor alpha (TNF-α) from HMECs, which was amplified in the presence of the protease-activated thrombin receptor 1 (PAR1) activator thrombin, but could be omitted by selectively blocking the PAR1 receptor. The amount and activity of the TNF-α secreted by HMECs stimulated with KTx-IgG from patients with vasculopathy was sufficient to induce subsequent THP-1 monocytic cell activation. Furthermore, AP-1/c-FOS, was identified as crucial transcription factor complex controlling the KTx-IgG-induced endothelial TNF-α synthesis, and mircoRNA-let-7f-5p as a regulatory element in modulating the underlying signaling cascade. In conclusion, exposure of HMECs to KTx-IgG from patients with allograft vasculopathy, but not KTx-IgG from patients without vasculopathy or healthy Con-IgG, triggers signaling through the PAR1-AP-1/c-FOS-miRNA-let7-axis, to control TNF-α gene transcription and TNF-α-induced monocyte activation. These observations offer a greater mechanistic understanding of endothelial cells and subsequent immune cell activation in the clinical setting of transplant vasculopathy that can eventually lead to transplant failure, irrespective of alloantigen-directed responses.

Expanded Hemodialysis ameliorates uremia-induced impairment of vasculoprotective KLF2 and concomitant proinflammatory priming of endothelial cells through an ERK/AP1/cFOS-dependent mechanism

Aims

Expanded hemodialysis (HDx) therapy with improved molecular cut-off dialyzers exerts beneficial effects on lowering uremia-associated chronic systemic microinflammation, a driver of endothelial dysfunction and cardiovascular disease (CVD) in hemodialysis (HD) patients with end-stage renal disease (ESRD). However, studies on the underlying molecular mechanisms are still at an early stage. Here, we identify the (endothelial) transcription factor Krüppel-like factor 2 (KLF2) and its associated molecular signalling pathways as key targets and regulators of uremia-induced endothelial micro-inflammation in the HD/ESRD setting, which is crucial for vascular homeostasis and controlling detrimental vascular inflammation.

Methods and results

First, we found that human microvascular endothelial cells (HMECs) and other typical endothelial and kidney model cell lines (e.g. HUVECs, HREC, and HEK) exposed to uremic serum from patients treated with two different hemodialysis regimens in the Permeability Enhancement to Reduce Chronic Inflammation II (PERCI-II) crossover clinical trial - comparing High-Flux (HF) and Medium Cut-Off (MCO) membranes - exhibited strongly reduced expression of vasculoprotective KLF2 with HF dialyzers, while dialysis with MCO dialyzers led to the maintenance and restoration of physiological KLF2 levels in HMECs. Mechanistic follow-up revealed that the strong downmodulation of KLF2 in HMECs exposed to uremic serum was mediated by a dominant engagement of detrimental ERK instead of beneficial AKT signalling, with subsequent AP1-/c-FOS binding in the KLF2 promoter region, followed by the detrimental triggering of pleiotropic inflammatory mediators, while the introduction of a KLF2 overexpression plasmid could restore physiological KLF2 levels and downmodulate the detrimental vascular inflammation in a mechanistic rescue approach.

Conclusion

Uremia downmodulates vasculoprotective KLF2 in endothelium, leading to detrimental vascular inflammation, while MCO dialysis with the novel improved HDx therapy approach can maintain physiological levels of vasculoprotective KLF2.

Increased Myeloperoxidase Concentrations in Saliva could Reflect Increased Body Mass and Oral Microinflammation

BACKGROUND

Increased myeloperoxidase (MPO) levels in saliva are thought to reflect ongoing periodontal inflammation. Less clear is whether and to what extent salivary MPO is increased as a result of systemic inflammation.

METHODS

In the present study, we aimed to determine which demographic, anthropometric, biochemical, and dental parameters affect the level of MPO in whole mixed saliva in healthy adults with no apparent inflammatory lesions in the oral cavity. Thus, 113 individuals, aged 20-61 years (including 30.1% men and 23.9% smokers), were examined.

RESULTS

In the univariate analysis, higher levels of MPO in saliva were found to be associated with age, an increased body mass index (BMI), higher levels of cytokines tumour necrosis factor-α and interleukin-6, as well as poorer oral hygiene, gingival status, and lower saliva flow. Multivariate logistic regression analysis determined that the main predictors of MPO concentration in saliva were BMI and stimulated saliva flow rate.

CONCLUSIONS

Overall, an increase in MPO in saliva could be related to an increase in BMI, possibly as a result of subclinical chronic microinflammation, which also involves the gingiva.

Ang II Promotes ET-1 Production by Regulating NOX2 Activity Through Transcription Factor Oct-1

BACKGROUND

Increasing evidence suggests that superoxide ions produced by NOX (nicotinamide adenine dinucleotide phosphate oxidases) mediate vascular effects of Ang II (angiotensin II) evoked by atherogenic diets. Here, we analyzed the mechanism by which NOX2 contributes to Ang II-induced ET-1 (endothelin 1) production in human microvascular endothelial cells.

METHODS

The effects of high-fat diet were compared between WT (wild type) and Nox2 (mouse NOX2 gene)-deficient mice. ET-1 production and NOX2 expression by human microvascular endothelial cells in vitro were analyzed by ELISA, reverse transcription quantitative polymerase chain reaction, electrophoretic mobility shift assay, promoter deletions, RNA interference, and pharmacological inhibition. Production of superoxide anions was visualized by fluorescent cell labeling.

RESULTS

Feeding mice high-fat diet for 10 weeks increased cardiac expression and plasma levels of Ang II and ET-1 in WT but not in Nox2-deficient animals. Exposure of human microvascular endothelial cells to Ang II resulted in increased ET-1 production, which could be blocked by silencing NOX2 (human NOX2 gene). Ang II promoted NOX2 expression through induction of the Oct-1 (human/mouse octamer binding transcription factor 1 protein) and activation of the NOX2 promoter region containing Oct-1-binding sites. Stimulation of NOX2 expression by Ang II was associated with increased production of superoxide anions. Inhibition of Oct-1 by small interfering RNA reduced Ang II-induced NOX2 expression and superoxide anion production, and neutralization of superoxide by SOD (superoxide dismutase) abolished Ang II-stimulated ET1 (human ET-1 gene) promoter activity, ET1 mRNA expression, and ET-1 release.

CONCLUSIONS

Ang II may promote ET-1 production in the endothelium in response to atherogenic diets through a mechanism that involves the transcription factor Oct-1 and the increased formation of superoxide anions by NOX2.

Effect of the one-day fasting on cortisol and DHEA daily rhythm regarding sex, chronotype, and age among obese adults

Introduction

Physiological and biochemical processes in the human body occur in a specific order and show rhythmic variability. Time dependence characterizes the secretion of cortisol and dehydroepiandrosterone (DHEA). One-day fasting implies alternating fasting days and eating days. The study aimed to determine how 24-h fasting affects the daily rhythm of cortisol and DHEA levels in obese people while taking into account gender and chronotype.

Methods

Forty-nine obese patients (BMI 32.2-67.1 kg/m²; 25 women and 24 men) underwent a 3-week hospital-controlled calorie restriction diet to reduce body weight. During hospitalization, patients fasted for 1 day, during which only water could be consumed. Samples of whole mixed unstimulated saliva were collected at 2-3-h intervals over a 64-h period and analyzed for cortisol and DHEA by immunoassays. The individual chronotypes were assessed by the morning and evening questionnaire, according to Horne and Östberg. Three components of daily rhythm were evaluated: amplitude, acrophase, and the so-called MESOR.

Results

Cortisol rhythm showed differences in amplitude (p = 0.0127) and acrophase (p = 0.0005). The amplitude on the fasting day was 11% higher (p = 0.224) than the day after. The acrophase advanced on the day of fasting, 48 min earlier than the day before (p = 0.0064), and by 39 min to the day after fasting (p = 0.0005). In the rhythm of DHEA, differences were found in the MESOR (p = 0.0381). The MESOR on the fasting day increased.

Discussion

Our results obtained during 64 consecutive hours of saliva sampling suggest that one-day fasting may affect three components of cortisol and DHEA daily rhythm. Additionally, no differences were found in the daily rhythm between the morning and evening chronotypes and between females and males. Although aging did not influence daily cortisol rhythm, DHEA amplitude, MESOR, and acrophase changed with age. To the best of our knowledge, this is the first presentation of changes in DHEA rhythm during one-day fasting.

Soluble receptor for advanced glycation end products (sRAGE) correlates with obesity-related parameters, and it is not easy to be modified by moderate caloric restriction in obese humans

Deficiency of a soluble form of the advanced glycation end products receptor (sRAGE) is implicated in obesity-induced complications. Serum sRAGE is inclined to be modified by changes in body weight. We analysed serum sRAGE concentrations in patients with obesity undergoing moderate calorie restriction, which mimics the real-life situation and is not harmful to obese humans. Serum sRAGE was measured by immunoassay in 50 patients with obesity who underwent calorie restriction by 300-500 kcal/day for 8 weeks. In effect calorie restriction resulted in an expected decrease in body weight (by 2.1 kg for an 8-week intervention, p<0.0001), as well as reduced systolic blood pressure, modified dyslipidemia (cholesterol, triglycerides), reduced obesity-related inflammation (tumor necrosis factor-alfa, interleukin-6, C-reactive protein), improved insulin sensitivity. However, it was not accompanied by any significant change in sRAGE concentration. There was a strong negative correlation between BMI and the sRAGE level. Accordingly, the levels of sRAGE were the highest in lean control. In conclusion: a modest weight reduction is unlikely to improve decreased sRAGE levels.

Angiogenic Role of Mesothelium-Derived Chemokine CXCL1 During Unfavorable Peritoneal Tissue Remodeling in Patients Receiving Peritoneal Dialysis as Renal Replacement Therapy

Peritoneal dialysis (PD) is a valuable ‘home treatment’ option, even more so during the ongoing Coronavirus pandemic. However, the long-term use of PD is limited by unfavourable tissue remodelling in the peritoneal membrane, which is associated with inflammation-induced angiogenesis. This appears to be driven primarily through vascular endothelial growth factor (VEGF), while the involvement of other angiogenic signaling pathways is still poorly understood. Here, we have identified the crucial contribution of mesothelial cell-derived angiogenic CXC chemokine ligand 1 (CXCL1) to peritoneal angiogenesis in PD. CXCL1 expression and peritoneal microvessel density were analysed in biopsies obtained by the International Peritoneal Biobank (NCT01893710 at www.clinicaltrials.gov), comparing 13 children with end-stage kidney disease before initiating PD to 43 children on chronic PD. The angiogenic potential of mesothelial cell-derived CXCL1 was assessed in vitro by measuring endothelial tube formation of human microvascular endothelial cells (HMECs) treated with conditioned medium from human peritoneal mesothelial cells (HPMCs) stimulated to release CXCL1 by treatment with either recombinant IL-17 or PD effluent. We found that the capillary density in the human peritoneum correlated with local CXCL1 expression. Both CXCL1 expression and microvessel density were higher in PD patients than in the age-matched patients prior to initiation of PD. Exposure of HMECs to recombinant CXCL1 or conditioned medium from IL-17-stimulated HPMCs resulted in increased endothelial tube formation, while selective inhibition of mesothelial CXCL1 production by specific antibodies or through silencing of relevant transcription factors abolished the proangiogenic effect of HPMC-conditioned medium. In conclusion, peritoneal mesothelium-derived CXCL1 promotes endothelial tube formation in vitro and associates with peritoneal microvessel density in uremic patients undergoing PD, thus providing novel targets for therapeutic intervention to prolong PD therapy.

Changes in Salivary Parameters of Oral Immunity after Biologic Therapy for Inflammatory Bowel Disease

We previously observed that inflammatory bowel disease (IBD) may compromise oral host defense, as assessed by decreased salivary levels of immunoglobulin A (IgA) and myeloperoxidase (MPO). Biologic therapy with inhibitors of cytokines or adhesion molecules is increasingly used for patients with IBD. Little is known, however, about how this treatment modality affects the release and properties of saliva. Here, we aimed to determine how biologic therapy in patients who had not responded to previous standard treatment with conventional drugs affected the salivary concentration of IgA and MPO. To this end, unstimulated whole mixed saliva was collected before treatment or after 10-12 weeks of therapy from 27 patients with Crohn's disease (CD) and 24 patients with ulcerative colitis (UC). After the induction phase of therapy with biologics, salivary levels of IgA and MPO increased significantly in UC, but not in CD patients. These increases were approximately 8-fold and 6-fold, for IgA and MPO, respectively. Moreover, these effects occurred in UC patients who responded successfully to therapy, but not in those who failed to improve. Furthermore, the relative increases in salivary IgA and MPO correlated with the relative decrease in UC severity, as assessed by the Mayo scale. These data indicate that the successful therapy with biologics in UC patients results also in improved oral host defense. However, it remains to be determined why such an effect does not occur during therapy for CD.

Expanded Hemodialysis Therapy Ameliorates Uremia-Induced Systemic Microinflammation and Endothelial Dysfunction by Modulating VEGF, TNF-α and AP-1 Signaling

Abstract

Systemic chronic microinflammation and altered cytokine signaling, with adjunct cardiovascular disease (CVD), endothelial maladaptation and dysfunction is common in dialysis patients suffering from end-stage renal disease and associated with increased morbidity and mortality. New hemodialysis filters might offer improvements. We here studied the impact of novel improved molecular cut-off hemodialysis filters on systemic microinflammation, uremia and endothelial dysfunction. Human endothelial cells (ECs) were incubated with uremic serum obtained from patients treated with two different hemodialysis regimens in the Permeability Enhancement to Reduce Chronic Inflammation (PERCI-II) crossover clinical trial, comparing High-Flux (HF) and Medium Cut-Off (MCO) membranes, and then assessed for their vascular endothelial growth factor (VEGF) production and angiogenesis. Compared to HF membranes, dialysis with MCO membranes lead to a reduction in proinflammatory mediators and reduced endothelial VEGF production and angiogenesis. Cytokine multiplex screening identified tumor necrosis factor (TNF) superfamily members as promising targets. The influence of TNF-α and its soluble receptors (sTNF-R1 and sTNF-R2) on endothelial VEGF promoter activation, protein release, and the involved signaling pathways was analyzed, revealing that this detrimental signaling was indeed induced by TNF-α and mediated by AP-1/c-FOS signaling. In conclusion, uremic toxins, in particular TNF-signaling, promote endothelial maladaptation, VEGF expression and aberrant angiogenesis, which can be positively modulated by dialysis with novel MCO membranes.

Translational Perspective and Graphical Abstract

Systemic microinflammation, altered cytokine signaling, cardiovascular disease, and endothelial maladaptation/dysfunction are common clinical complications in dialysis patients suffering from end-stage renal disease. We studied the impact of novel improved medium-cut-off hemodialysis filters on uremia and endothelial dysfunction. We can show that uremic toxins, especially TNF-signaling, promote endothelial maladaptation, VEGF expression and aberrant angiogenesis, which can be positively modulated by dialysis with novel improved medium-cut-off membranes.

Autoantibodies from Patients with Scleroderma Renal Crisis Promote PAR-1 Receptor Activation and IL-6 Production in Endothelial Cells

BACKGROUND

Scleroderma renal crisis (SRC) is a life-threatening complication of systemic sclerosis (SSc). Autoantibodies (Abs) against endothelial cell antigens have been implicated in SSc and SRC. However, their detailed roles remain poorly defined. Pro-inflammatory cytokine interleukin-6 (IL-6) has been found to be increased in SSc, but its role in SRC is unclear. Here, we aimed to determine how the autoantibodies from patients with SSc and SRC affect IL-6 secretion by micro-vascular endothelial cells (HMECs).

METHODS

Serum IgG fractions were isolated from either SSc patients with SRC (n = 4) or healthy individuals (n = 4) and then each experiment with HMECs was performed with SSc-IgG from a separate patient or separate healthy control. IL-6 expression and release by HMECs was assessed by quantitative reverse transcription and quantitative PCR (RT-qPCR) and immunoassays, respectively. The mechanisms underlying the production of IL-6 were analyzed by transient HMEC transfections with IL-6 promoter constructs, electrophoretic mobility shift assays, Western blots and flow cytometry.

RESULTS

Exposure of HMECs to IgG from SSc patients, but not from healthy controls, resulted in a time- and dose-dependent increase in IL-6 secretion, which was associated with increased AKT, p70S6K, and ERK1/2 signalling, as well as increased c-FOS/AP-1 transcriptional activity. All these effects could be reduced by the blockade of the endothelial PAR-1 receptor and/or c-FOS/AP-1silencing.

CONCLUSIONS

Autoantibodies against PAR-1 found in patients with SSc and SRC induce IL-6 production by endothelial cells through signalling pathways controlled by the AP-1 transcription factor. These observations offer a greater understanding of adverse endothelial cell responses to autoantibodies present in patients with SRC.

Moderate Caloric Restriction Partially Improved Oxidative Stress Markers in Obese Humans

Oxidative stress and inflammation are implicated in obesity. Therefore, we investigated whether moderate and short-term calorie restriction (CR) reflects a real-life situation, mediates weight loss, and improves oxidative stress markers. We analyzed oxidative stress markers in patients with obesity undergoing moderate CR. Serum oxidative stress markers (myeloperoxidase (MPO), superoxide dismutase (SOD), catalase, total antioxidant status (TAS), and reactive oxygen species (ROS) (generation by endothelial cells in vitro)) were measured in 53 subjects (mean BMI 37.8 ± 5.9 kg/m²) who underwent 8 weeks of CR, which included a reduction of 300-500 kcal/day. MPO was the most CR-sensitive parameter. The mean level of serum MPO in patients with obesity was 20% higher than that in post CR intervention (p < 0.001). SOD increased by 12% after CR (p < 0.05), which was largely due to the improvement in glucose tolerance and the reduction in insulin resistance after CR. Other tested parameters were not modified during the treatment. CR resulted in an expected decrease in body weight (by 5.9 ± 4.6 kg, p < 0.0001) and other anthropometric parameters. Additionally, it was accompanied by a significant change in hsCRP, hsTNF alpha, hsIL-6, leptin (all p < 0.0001), and HOMA-IR (p < 0.05). Cardiovascular and metabolic parameters were also partially improved. Short-term, moderate CR partially improves antioxidant capacity but is enough to substantially change anthropometric parameters in obese patients. Our observations indicate that mimicking real-life situations and low-cost dietary intervention can be successfully implemented in obesity treatment with a simultaneous moderate effect on antioxidant status.

Mixed reality interactive visualization of cardiovascular anatomy in interventional lab – clinical implementation in transvascular patent ductus arteriosus closure

Aim

Three-dimensional (3D) noninvasively acquired datasets containing anatomical information about the heart are a modern option for procedural support during percutaneous cardiac interventions. We present initial experience of patent ductus arteriosus (PDA) closure with workflow integrated with innovative mixed reality display (MRD) to improve 3D perception and navigation in 3D computed tomography angiographic (CTA) datasets.

Methods

We report incorporation of intraprocedural mixed-reality display of segmented CTA (computed tomography angiography) data using a voice- and gesture controlled head-mounted display during routine percutaneous occlusions of PDA in adults. A dedicated software pathway was used for files conversion, real-time Wi-Fi streaming of 3D rendering from PC to device and manipulation of spatial data during the procedures.

Results

Pre-recorded CTA studies of aorta and ductus were manually segmented and uploaded into custom designed 3D DICOM for realtime export to MRD device. 3D holograms were successfully displayed during the procedure by commercially available head-mounted display allowing touchless control and image sharing within cath-lab. Wiring of PDA aortic orifice was assisted by 3D hologram controlled by the imaging specialist and shared by the operator. Thus, MRD using evolving versions of custom software was successfully executed with segmented data presented as a semitransparent cubic hologram positioned in a convenient part of visual field allowing real-world action and with touchless control by medical team. Operator appreciated the use of MRD hologram realistically visualizing spatial relationships as practical aid to establish anatomical relationships and facilitate entry into ductus orifice. Procedures were successfully completed using arteriovenous guidewire loop to implant vascular occluders.

Conclusions

We demonstrate the methodology and software evolution (segmentation, data fusion) allowing practical implementation of intraprocedural mixed reality display of 3D CTA data, with sterile, touchless control of holographic image shared by interventional and imaging team to support percutaneous PDA closure.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): MEDAPP

Control of neutrophil influx during peritonitis by transcriptional cross-regulation of chemokine CXCL1 by IL-17 and IFN-γ

Neutrophil infiltration is a hallmark of peritoneal inflammation, but mechanisms regulating neutrophil recruitment in patients with peritoneal dialysis (PD)-related peritonitis are not fully defined. We examined 104 samples of PD effluent collected during acute peritonitis for correspondence between a broad range of soluble parameters and neutrophil counts. We observed an association between peritoneal IL-17 and neutrophil levels. This relationship was evident in effluent samples with low but not high IFN-γ levels, suggesting a differential effect of IFN-γ concentration on neutrophil infiltration. Surprisingly, there was no association of neutrophil numbers with the level of CXCL1, a key IL-17-induced neutrophil chemoattractant. We investigated therefore the production of CXCL1 by human peritoneal mesothelial cells (HPMCs) under in vitro conditions mimicking clinical peritonitis. Stimulation of HPMCs with IL-17 increased CXCL1 production through induction of transcription factor SP1 and activation of the SP1-binding region of the CXCL1 promoter. These effects were amplified by TNFα. In contrast, IFN-γ dose-dependently suppressed IL-17-induced SP1 activation and CXCL1 production through a transcriptional mechanism involving STAT1. The SP1-mediated induction of CXCL1 was also observed in HPMCs exposed to PD effluent collected during peritonitis and containing IL-17 and TNFα, but not IFN-γ. Supplementation of the effluent with IFN-γ led to a dose-dependent activation of STAT1 and a resultant inhibition of SP1-induced CXCL1 expression. Transmesothelial migration of neutrophils in vitro increased upon stimulation of HPMCs with IL-17 and was reduced by IFN-γ. In addition, HPMCs were capable of binding CXCL1 at their apical cell surface. These observations indicate that changes in relative peritoneal concentrations of IL-17 and IFN-γ can differently engage SP1-STAT1, impacting on mesothelial cell transcription of CXCL1, whose release and binding to HPMC surface may determine optimal neutrophil recruitment and retention during peritonitis. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Glucose Degradation Products and Peritoneal Membrane Function

Background

The bioincompatibility of peritoneal dialysis fluids (PDF) in current use has been partially attributed to the presence of glucose degradation products (GDPs), which are generated during heat sterilization of PDF. Several of the GDPs have been identified and we have recently demonstrated that these GDPs per se may impair the viability and function of human peritoneal mesothelial cells (HPMC) in vitro. It is also possible that GDP-related toxicity is further exacerbated by the milieu of PDF. We review the current literature on GDP and present the results of experiments comparing the impact of heat- and filter-sterilized PDF on the viability and function of HPMC.

Methods

Peritoneal dialysis fluids with low (1.5%) and high (4.25%) glucose concentrations were laboratory prepared according to the standard formula and sterilized either by heat (H-PDF; 121°C, 0.2 MPa, 20 minutes) or filtration (F-PDF; 0.2 μ). The buildup of GDP was confirmed by UV absorbance at 284 nm. Confluent HPMC monolayers were exposed to these solutions mixed 1:1 with standard M199 culture medium. After 24 hours, cell viability was assessed with the MTT assay, and interleukin-1β–stimulated monocyte chemotactic protein-1 (MCP-1) release with specific immunoassay.

Results

Exposure of HPMC to H-PDF resulted in a significant decrease in cell viability, with solutions containing 4.25% glucose being more toxic than 1.5% glucose-based PDF (27.4% ± 3.4% and 53.4% ± 11.0% of control values, respectively). In contrast, viability of HPMC exposed to F-PDF was not different from that of control cells. Moreover, treatment with H-PDF impaired the release of MCP-1 from HPMC to a significantly greater degree compared to F-PDF (17.4% and 24.9% difference for low and high glucose PDF, respectively).

Conclusions

Exposure of HPMC to H-PDF significantly impairs cell viability and the capacity for generating MCP-1 compared to F-PDF. This effect is likely to be mediated by GDPs present in H-PDF but not in F-PDF.

Influence of Neutral-Ph Dialysis Solutions on the Peritoneal Membrane: A Long-Term Investigation in Rats

♦ Objective

Glucose degradation products (GDPs) and low pH are potential causes of bioincompatibility of peritoneal dialysis fluids (PDFs). The aim of the present study was to compare the effect of 6 weeks’ exposure of the peritoneum in rats to two different PDFs: a standard PDF with a low pH and high level of GDPs (CAPD 3: Fresenius Medical Care, Bad Homburg, Germany), and a modified PDF with a low level of GDPs and a physiologic pH (CAPD 3 Balance: Fresenius Medical Care).

♦ Methods

After catheter implantation, rats were exposed twice daily for 6 weeks to CAPD 3 fluid or to CAPD 3 Balance. At the beginning and at the end of the study, a 4-hour dwell was performed in every rat to evaluate intraperitoneal inflammation and its effect on total collagen synthesis in the in vitro cultured rat mesothelial cells ( ex vivo study). Additionally, after 6 weeks’ exposure, the peritoneal cavity was opened, and macroscopic changes were evaluated according to a semiquantitative scale. Peritoneal samples were also taken for morphology study.

♦ Results

In rats treated with CAPD 3 fluid, intraperitoneal inflammation was comparable at the beginning and at the end of the experiment. In animals exposed to CAPD 3 Balance, the intensity of the intraperitoneal inflammation decreased during the study (cell count, p = 0.0781; neutrophil:macrophage ratio, p < 0.01; nitrite concentration, p < 0.05; hyaluronan level, p < 0.05). The capacity of effluent dialysate from CAPD 3 rats to activate collagen synthesis in in vitro–cultured mesothelial cells was the same at the beginning and at the end of the study. In the CAPD 3 Balance group, this capacity was statistically significantly lower at the end of the study than at the beginning ( p < 0.05). The mean thickness of the visceral peritoneum was comparable in both groups of animals, but, macroscopically, more severe fibrosis was found in the peritoneum of rats exposed to CAPD 3 as compared with animals treated with CAPD 3 Balance ( p < 0.05).

♦ Conclusion

We showed that, in the rat model of peritoneal dialysis, chronic exposure of the peritoneum to PDFs with low GDPs and a physiologic pH diminished the intraperitoneal inflammatory reaction induced by dialysis, and reduced peritoneal fibrosis.

Lessons from Basic Research for Pd Treatment

Over the past 30 years, the focus of peritoneal dialysis research has changed from the technical issues related to the establishment of clinical peritoneal dialysis to complex problems of peritoneal membrane biology. Here, we present how these research topics developed, discuss their significance for clinical science, and outline future challenges for peritoneal dialysis research.

In Vitro Study of the Mechanism of Potassium Transport into Human Mesothelial Cells. I: Effect of Hyperosmolality

Objective

To study the mechanism(s) of potassium transport into human mesothelial cells (HMC) exposed to osmotic solutes.

Design

Using potassium analog 86Rb, we evaluated its intracellular transport through three pathways: 1. blocked by ouabain; 2. blocked by furosemide but not by ouabain; 3. blocked by neither furosemide nor ouabain. Experiments were performed in a normotonic medium (control) or in a medium supplemented with osmotic solutes (glucose, glycerol, mannitol). Both the acute and chronic effects of osmotic solutes on potassium transport were studied.

Results

The acute exposure of mesothelial cells to osmotic solutes modifies the intracellular transport of potassium through all studied channels, and the effect is specific for every solute. In mesothelial cells exposed over 7 days to glucose (90 mM), the intracellular transport via ouabain and furosemide-blocked channels is decreased, whereas it is increased through the third pathway. Total intracellular accumulation of 86Rb (potassium) ions in mesothelial cells cultured in a medium supplemented with various concentrations of glucose is decreased, and this effect is proportional to the concentration of glucose in the medium.

Conclusions

The intracellular transport of potassium in mesothelial cells is regulated through at least three independent mechanisms. Acute or chronic exposure of mesothelial cells to a hypertonic medium affects the intracellular accumulation of potassium, an d this effect is specific for the various osmotic solutes.

Insulin Stimulates the Activity of Na+/K+-Atpase in Human Peritoneal Mesothelial Cells

Objective

To assess the effect of insulin on the Na+/ K+-ATPase expression and activity in human peritoneal mesothelial cells (HPMC).

Methods

HPMC were isolated from the omental tissue of non-uremic patients, grown to confluence and rendered quiescent by serum deprivation for 24 hours. The activity of Na+/K+-ATPase was determined by measuring the ouabain-sensitive86Rb uptake. To assess whether the effect of insulin was related to changes in [Na+]i the sodium influx was measured with 22Na and the activity of Na+/K+ -A TPase was assessed in the presence of amiloride. Expression of Na+/K+ -A TPaseα1’ α2 and β1-subunit mRNAs was determined by RT/PCR.

Results

Exposure of HPMC to insulin resulted in a time and dose-dependent increase in the Na+/K+-ATPase activity. After 60 minutes the ouabain-sensitive 86Rb up take (cpm/104 cells) was increased from 6650±796 in control cells to 9763±1212 in HPMC exposed to 100 mU/ mL insulin (1.5-fold increase; n=4, P<0.05). In addition, incubation of HPMC with 100 mU/mL insulin resulted in a time-dependent increase in the 22Na influx. Pre-exposure of HPMC to 1 mM amiloride reduced the activity of Na+/K+-A TPase but did not block the stimulatory effect of insulin. RT/PCR analysis revealed that HPMC constitutively expressed α1 and β1-subunit mRNAs while the α2-subunit mRNA was barely detectable. Exposure of HPMC to insulin for up to 24 hours was not associated with any changes in the expression of either α1’ α2 or B1-subunit.

Conclusion

Insulin stimulates the Na+/K+-ATPase activity in HPMC in a time and dose-dependent manner. This effect appears to mediated by an increase in [Na+]i and is not related to alterations in Na+/K+-ATPase subunit mRNAs expression.

Glucose Degradation Products and the Peritoneal Mesothelium

Conventional heat-sterilized, glucose-based peritoneal dialysis (PD) fluids contain significant amounts of glucose degradation products (GDPs) such as aldehydes and dicarbonyl compounds (glyoxal, methylglyoxal). These GDPs have been shown to impair cell functions in various in vitro experimental models. In peritoneal mesothelial cells, GDPs dose-dependently inhibit cell proliferation and mediator synthesis. In addition, some GDPs potently promote generation of advanced glycation end-products (AGEs). Immunohistochemistry finds AGEs in the peritoneal membrane of chronic continuous ambulatory peritoneal dialysis (CAPD) patients, suggesting that peritoneal AGE accumulation may be involved in chronic peritoneal fibrosis.

The formation of GDPs might be prevented by filter-sterilization of PD fluids. Another option is to separate the glucose and the buffer system in dual-chambered or multi-chambered containers. In these systems, the glucose is kept in a separate compartment at high concentration and very low pH—both conditions being known to minimize the degree of glucose decomposition during autoclaving. Initial experimental evidence suggests that these novel, multi-chambered fluids significantly improve in vitro biocompatibility; however, the clinical relevance of these results remains to be established in clinical trials.

Evidence for Less Irritation to the Peritoneal Membrane in Rats Dialyzed with Solutions Low in Glucose Degradation Products

Background

Acidic pH and the presence of glucose degradation products (GDP) are believed to compromise the biocompatibility of peritoneal dialysis fluids (PDF). The present study examines the effects of long-term exposure to GDP and low pH by comparing conventional PDF and a new, neutral pH, low GDP solution.

Methods

All experiments were performed using a chronic infusion model of dialysis in nonuremic rats. The animals were treated for 6 weeks with 2 daily injections of 4.25% glucose-containing PDF. The following PDF were tested: CAPD3 (single-chamber bag, low pH, high GDP), CAPD3 pH 7.4 (single-chamber bag, neutral pH, high GDP), CAPD3-Balance (double-chamber bag, neutral pH, low GDP). All test solutions were obtained from Fresenius Medical Care, Bad Homburg, Germany.

Results

After 6 weeks of exposure, peritoneal permeability to water, urea, creatinine, glucose, and sodium, assessed by peritoneal equilibration test, was similar in all groups. However, compared to other PDF, dialysis with CAPD3-Balance was associated with reduced concentrations of protein and hyaluronan in the dialysate, decreased peritoneal eosinophilia, and reduced dialysate levels of chemokines CCL2/MCP-1 and CCL5/RANTES. Morphologic changes in the peritoneal membrane of CAPD3-Balance-treated animals were much less pronounced and included reduced vascular density, preservation of the mesothelial monolayer and intercellular junction, and no reduplication of the submesothelial basement membrane.

Conclusions

A new generation of PDF with physiologic pH and low GDP level produce less irritation to the peritoneal membrane and better preserve its structural integrity. This effect seems to be related predominantly to minimized GDP concentrations.

Effects of Peritoneal Dialysis Solutions on the Peritoneal Membrane: Clinical Consequences

This review provides an overview of recent studies that show the clinical significance of biocompatibility of peritoneal dialysis fluids.

Technological Advances in Peritoneal Dialysis Research Peritoneal Cell Culture: Fibroblasts

Fibroblasts have been traditionally viewed as providing little more than a structural lattice for other cell types. However, recent data indicate that fibroblasts play a key and early role in many pathophysiological processes, including inflammation, fibrosis, and neoplasia. Moreover, depending on the anatomical location, fibroblasts display significant functional heterogeneity. Therefore, it is important to study the subpopulation of fibroblasts derived exactly from the organ of interest rather than to extrapolate the observations made in other fibroblast subsets. Cell culture provides a powerful tool for studying the role of fibroblasts in various contexts. In this review, we describe procedures for establishing and identifying primary cultures of human peritoneal fibroblasts. We also briefly discuss the potential involvement of peritoneal fibroblasts in peritoneal pathology.

The Role of the Glyoxalase Pathway in Reducing Mesothelial Toxicity of Glucose Degradation Products

Background

The glucose degradation products (GDP) present in conventional peritoneal dialysis fluids (PDF) may exert adverse effects toward human peritoneal mesothelial cells (HPMC). Some GDP can be detoxified by the glyoxalase/glutathione pathway. It has been shown that the addition of glyoxalase I (GLO-I) and reduced glutathione (GSH) to PDF effectively eliminates GDP. We have therefore examined the GLO-I/GSH system in HPMC and assessed the impact of GLO-I/GSH-treated PDF on the viability and function of HPMC.

Methods

Heat-sterilized PDF (H-PDF) was incubated in the presence or absence of GLO-I and GSH for 1 hour at 37°C, and then mixed with an equal volume of serum-free M199 medium and applied to HPMC in culture. After 24 hours, HPMC were assessed for viability, the release of interleukin-6, GLO-I activity, and cellular glutathione. The effects were compared to those exerted by filter-sterilized PDF (F-PDF), which was devoid of GDP.

Results

Exposure of HPMC to H-PDF resulted in reduced GLO-I activity, GSH depletion, and a decrease in cell viability. Pretreatment of H-PDF with either a combination of GLO-I and GSH or GSH alone markedly reduced inhibitory effects of H-PDF toward HPMC, as measured by cell viability and interleukin-6 generation. Exposure of HPMC to the GSH precursor L-2-oxothiazolidine-carboxylic acid increased cellular GSH and prevented the loss of GLO-I activity in response to H-PDF.

Conclusions

Exposure to conventional GDP-rich PDF impairs the activity of the glyoxalase/glutathione system in HPMC. Pretreatment of PDF with GSH or replenishment of cellular GSH protects HPMC against GDP-mediated toxicity.

Quality of design and reporting of animal research in peritoneal dialysis: A scoping review

The concerns about reproducibility and validity of animal studies are partly related to poor experimental design and reporting. Here, we undertook a scoping review of the literature to determine the extent and quality of reporting of animal studies on peritoneal dialysis (PD). Online databases were searched to identify 567 relevant original articles published between 1979 and 2018. These were analyzed with respect to bibliographic parameters and general aspects of animal experimentation. A subgroup of 120 studies was analyzed in detail in terms of the impact on the reporting quality of the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines for animal studies. The number of animal studies on PD increased continuously over the years with a thematic shift toward long-term preservation of the peritoneum as a dialyzing organ. There were significant deficiencies in research design with the lack of sample size estimation, randomization, and blinding being the commonest shortcomings. The description of animal numbers, housing conditions, use of medication, and statistical analysis was incomplete. The introduction in 2010 of the ARRIVE guidelines produced very little improvement in the completeness of reporting regardless of journal impact factor. The animal studies on PD suffer from deficits in experimental protocols and transparent reporting. These drawbacks need to be corrected to ensure high-quality and much-needed animal research in PD.

Amaranth (Amaranthus cruentus L.) and canola (Brassica napus L.) oil impact on the oxidative metabolism of neutrophils in the obese patients

CONTEXT

Amaranth and canola oils have been used traditionally. Amaranth has been identified as being of interest because of its outstanding nutritive value. Amaranth oil is a rich source of highly unsaturated fats and so could be a valuable dietary alternative for individuals affected with obesity. Reactive oxygen species (ROS) are postulated to be involved in systemic inflammation and oxidative stress. Activated polymorphonuclear neutrophils (PMNs) generate high amounts of reactive oxygen species.

OBJECTIVE

Our study investigates the impact of amaranth and canola oils supplementation on oxidative metabolism in patients with obesity. We hypothesized that, due to its lipid-lowering and antioxidant properties, amaranth and canola oil would protect against oxidative stress.

MATERIALS AND METHODS

We tested 19 obese patients [body mass index (BMI) = 41.1 ± 7.8 kg/m², (mean ± SD)]. The protocol consisted of two stages: a run-in phase of 2 weeks and an experimental stage - canola or amaranth oil supplementation (20 mL/d) with calorie restriction diet for 3 weeks. The neutrophil oxidative burst was expressed by fluorescence intensity (IF).

RESULTS

The oxidative burst had increased significantly at the end of treatment in both groups IF: (21.4 ± 11.15 vs. 35.9 ± 20.3; mean ± SD) p < 0.05. The levels of IF were significantly higher in neutrophils of patients who received canola oil (41.05 ± 25.3) compared to those who received amaranth oil (28.4 ± 11.8) p < 0.05.

CONCLUSIONS

Canola oil exerts possible effects on oxidative burst activity in neutrophils in vivo conditions.

Tumour necrosis factor-alpha in uraemic serum promotes osteoblastic transition and calcification of vascular smooth muscle cells via extracellular signal-regulated kinases and activator protein 1/c-FOS-mediated induction of interleukin 6 expression

Background

Vascular calcification is enhanced in uraemic chronic haemodialysis patients, likely due to the accumulation of midsize uraemic toxins, such as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Here we have assessed the impact of uraemia on vascular smooth muscle cell (VSMC) calcification and examined the role of IL-6 and TNF-α as possible mediators and, most importantly, its underlying signalling pathway in VSMCs.

Methods

VSMCs were incubated with samples of uraemic serum obtained from patients treated with haemodialysis for renal failure in the Permeability Enhancement to Reduce Chronic Inflammation-I clinical trial. The VSMCs were assessed for IL-6 gene regulation and promoter activation in response to uraemic serum and TNF-α with reporter assays and electrophoretic mobility shift assay and for osteoblastic transition, cellular calcification and cell viability upon osteogenic differentiation.

Results

Uraemic serum contained higher levels of TNF-α and IL-6 compared with serum from healthy individuals. Exposure of VSMCs to uraemic serum or recombinant TNF-α lead to a strong upregulation of IL-6 mRNA expression and protein secretion, which was mediated by activator protein 1 (AP-1)/c-FOS-pathway signalling. Uraemic serum induced osteoblastic transition and calcification of VSMCs could be strongly attenuated by blocking TNF-α, IL-6 or AP-1/c-FOS signalling, which was accompanied by improved cell viability.

Conclusion

These results demonstrate that uraemic serum contains higher levels of uraemic toxins TNF-α and IL-6 and that uraemia promotes vascular calcification through a signalling pathway involving TNF-α, IL-6 and the AP-1/c-FOS cytokine-signalling axis. Thus treatment modalities aiming to reduce systemic TNF-α and IL-6 levels in chronic haemodialysis patients should be evaluated in future clinical trials.

Seasonal differences in rhythmicity of salivary cortisol in healthy adults

The existence of seasonal changes in secretion of stress hormones and inflammatory mediators by humans is not certain. Here, we aimed to determine whether concentrations of cortisol and IL-6 displayed seasonal rhythmicity. The study was performed in Poznań, Poland (52°N, 16°E) in 7 healthy female volunteers (age 22.6 ± 0.8 yr). Samples of whole mixed unstimulated saliva were collected in winter (February) and summer (June) at 2-h intervals over a 24-h period and analyzed for cortisol and IL-6 by immunoassays. During each season, the subjects answered questionnaires related to their sleeping habits, food intake, physical activity, and perceived seasonality. It turned out that salivary concentrations of cortisol followed a daily rhythm both in winter and summer, as determined by a cosine analysis. However, compared with the winter season, a midline-estimating statistic of rhythm in the summer was significantly higher. Moreover, the rhythm acrophase occurred ~4 h later in the summer than in the winter, whereas the amplitudes did not differ. These fluctuations did not correspond to sleeping habits, food and fluid intake, physical exercise, and the self-assessed chronotype. However, the individuals with higher scores on the seasonal affective disorder scale showed a tendency toward lower relative cortisol amplitude in the summer. In contrast to cortisol, salivary IL-6 concentration did not display daily rhythmicity, and its concentrations did not differ significantly between the seasons. In conclusion, in the summer, cortisol level in saliva is elevated, and its circadian pattern of secretion is shifted. The causes for these alterations do not seem to be related to lifestyle and thus remain to be established.

The intensity of joint pain in relation to changes in serum TNFα during therapy with anti-TNFα inhibitors

Introduction

Tumor necrosis factor-alpha (TNFα) inhibitors have significantly improved the outcomes of treatment for rheumatoid arthritis (RA). In the present study, we aimed to determine whether serum levels of TNFα during therapy with TNFα inhibitors do really reflect the disease activity and correspond to the intensity of pain experienced.

Materials and methods

Thirty RA patients were examined before and after 12 weeks of routine therapy with TNFα inhibitors. Serum levels of TNFα were measured with a high-sensitivity immunoassay and related to patients’ clinical and biochemical status. Disease activity was assessed by the modified disease activity score (DAS28).

Results

A median relative change in TNFα was 13%. The patients were stratified according to whether the relative change in serum TNFα after therapy was above or below this median value. The patients from both subgroups did not differ in baseline characteristics and response to therapy. However, the patients in whom serum TNFα increased after therapy above the median value had more tender joints after treatment than patients from the other group. Consequently, the number of tender joints after the treatment correlated with absolute TNFα concentrations at this time (r = 0.37; p = 0.049) and the magnitude of changes in serum TNFα correlated with a change in the number of tender joints (r = − 0.48; p = 0.008).

Conclusions

Circulating TNFα levels did not decrease in RA patients treated with TNFα inhibitors, despite clinical and biochemical improvement. It is possible, that circulating TNFα is responsible for the persistence of joint pain in this group of patients.

IL-17 in Peritoneal Dialysis-Associated Inflammation and Angiogenesis: Conclusions and Perspectives

Long-term peritoneal dialysis (PD) is associated with peritoneal membrane remodeling. This includes changes in peritoneal vasculature, which may ultimately lead to inadequate solute and water removal and treatment failure. The potential cause of such alterations is chronic inflammation induced by repeated episodes of infectious peritonitis and/or exposure to bioincompatible PD fluids. While these factors may jeopardize the peritoneal membrane integrity, it is not clear why adverse peritoneal remodeling develops only in some PD patients. Increasing evidence points to the differences that occur between patients in response to the same invading microorganism and/or the differences in the course of inflammatory reaction triggered by different species. Such differences may be related to the involvement of different inflammatory mediators. Here, we discuss the potential role of IL-17 in these processes with emphasis on its impact on peritoneal mesothelial cells and peritoneal vascularity.

Epithelial-to-Mesenchymal Transition and Migration of Human Peritoneal Mesothelial Cells Undergoing Senescence

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs) contributes to fibrotic thickening of the peritoneum that develops in patients on peritoneal dialysis (PD). The process is thought to be largely mediated by transforming growth factor-beta (TGF-β). As TGF-β has also been implicated in senescence of HPMCs, we have performed an exploratory study to examine if senescent HPMCs can undergo EMT.

METHODS

Omentum-derived HPMCs were rendered senescent by repeated passages in culture. Features of EMT were assessed by immunostaining and quantitative polymerase chain reaction (qPCR) at various stages of the HPMC lifespan and after treatment with or without TGF-β. The motility of HPMCs was assessed in a scratch wound migration assay.

RESULTS

Replicative senescence of HPMCs was associated with a gradual increase in the constitutive expression of EMT markers, including increased production of extracellular matrix proteins. However, senescent HPMCs also retained epithelial cell features such as cytokeratin, calretinin, and E-cadherin and showed decreased, rather than increased, motility. In contrast, exposure to TGF-β resulted in an up-regulation of mesenchymal markers and down-regulation of epithelial markers. Such effects of TGF-β occurred both in young and senescent cells, although they were less pronounced in senescence.

CONCLUSIONS

Senescence of HPMCs is associated with spontaneous development of several EMT features. At the same time, senescent HPMCs preserve epithelial cell-like characteristics and are less prone to develop a full EMT phenotype in response to TGF-β. These observations may support the concept of cellular senescence being antagonistically pleiotropic with regard to EMT.

The role of purinergic P2Y12 receptor blockers on the angiogenic properties of endothelial cells: an in vitro study

Pharmacotherapy with agents that inhibit platelet function has proven to be effective in the treatment of acute coronary syndrome. Proper re-endothelization after angioplasty prevents adverse cardiovascular events. Therefore, in this in vitro study we examined how antiplatelet P2Y₁₂ receptor blockers can affect endothelial cells' angiogenic properties. Endothelial cells were exposed to ticagrelor, prasugrel and clopidogrel in their highest concentrations obtained in serum after the treatment with loading and clinical doses. Further, the viability, apoptosis, and necrosis were tested and the following angiogenic properties such as proliferation, migration, invasiveness, tube formation, wound healing and the production of angiogenic mediators (bFGF, PDGF, MMP-2, Ang-2, TIMP-1). The results of this study showed that P2Y₁₂ receptor blockers in the tested concentrations are safe for endothelial cells. They neither induced necrosis or apoptosis nor changed the endothelial cell viability, migration, invasiveness, tube formation, wound healing, the production of VEGF or its receptors. However, they reduced cell proliferation. It was shown that out of these three drugs, ticagrelor in its loading concentration had the most potent angiogenic property. It reduced cell proliferation and changed the production of angiogenic (bFGF, MMP-2) and angiostatic mediators (Ang-2). In conclusion, P2Y₁₂ receptor blockers in the concentrations obtained in the serum during standard therapy reduced endothelial cell proliferation. Despite this slight antimitogenic effect, they did not change endothelial cell tube formation or wound healing. Out of the three tested drugs, ticagrelor had the most potent angiogenic effect in vitro, but not strong enough to disturb tube formation and wound healing.

Anti-inflammatory Activity and Phytochemical Profile of Galinsoga Parviflora Cav

The objective of this study was to evaluate the usefulness of a hydroalcoholic extract from Galinsoga parviflora herb (GP) in some aspects of the endothelial cell function necessary for anti-inflammatory activity and wound healing and relate these to the GP phytochemical profile. This study demonstrated that the GP extract caused a dose-dependent reduction of IL-6 secretion on IL-1β-stimulated endothelial cells. The IL-6 release was decreased to 33% ± 9% while this did not influence the IL-6 secretion without stimulation. Additionally, the GP extract exhibited an anti-hyaluronidase activity (IC₅₀ = 0.47 mg/mL), which was evidently stronger than the positive control kaempferol (IC₅₀ = 0.78 mg/mL) as well as a moderate and concentration-dependent, antioxidant activity. The results of the scratch assay showed that exposure of the endothelial cells to GP induced complete healing of the damage after 12 h of the study. The phytochemical profile of the extract was studied by using spectrophotometric (total amount of polyphenols and flavonoids) and UPLC (phenolic acids) methods. The main compound in the GP extract was a chlorogenic acid (2.00 ± 0.01 mg/g by UPLC). The total content of polyphenols was 98.30 ± 0.14 mg of chlorogenic acid equivalent/g of the dry herb and content of flavonoids amounted to 6.15 ± 0.41 mg quercetin equivalent/g of the dry herb. Moreover, the presence of flavonoids in G. parviflora was provided after their isolation and identification by spectroscopic methods. In conclusion, it demonstrated that application of GP in the treatment of skin lesions gives possibility of wound healing based on antioxidant, anti-inflammatory, and hyaluronidase-inhibiting activities of G. parviflora herb extract.

Diagnostic value of salivary CRP and IL-6 in patients undergoing anti-TNF-alpha therapy for rheumatic disease

Introduction

Saliva has been increasingly used as a diagnostic medium for disease detection and monitoring. The aim of this observational, prospective, pilot study was to investigate whether salivary concentrations of CRP and IL-6 correlate with those in serum and with the clinical course of a rheumatic disease.

Materials and methods

Nineteen patients with rheumatic disease newly scheduled for anti-TNFα therapy were included. Patients received anti-TNFα treatment (adalimumab, certolizumab, golimumab or infliximab) as per standard protocols. CRP and IL-6 were measured with high-sensitivity immunoassays before and after 12 weeks of therapy, according to standard regimens. The data were analyzed with nonparametric statistics.

Results

Concentrations of CRP in saliva correlated significantly with those in serum (R = 0.62; p < 0.0001) and decreased markedly after successful response to treatment. In patients with a limited response to treatment salivary CRP levels increased. In contrast to CRP, the salivary concentrations of IL-6 did not change significantly over the course of therapy and they did not correlate with serum IL-6 concentrations. Salivary levels of neither CRP nor IL-6 corresponded to parameters of oral health and hygiene.

Conclusions

Salivary CRP but not IL-6 could be of potential use for monitoring the rheumatic disease activity.

Salivary fingerprint of simple obesity

BACKGROUND

The nature of a link between poor oral health and obesity is not fully understood. It is also unclear if saliva contributes to it and whether the properties of saliva change as a result of an increase in body mass or rather as a consequence of obesity-associated comorbidities. This pilot study was undertaken in an attempt to determine if salivary biomarkers can identify obesity per se.

METHODS

Whole mixed saliva was analysed for 16 soluble parameters covering 4 categories (inflammation, oxidative stress, endothelial dysfunction, adipokines). In the discovery group, 19 obese and 25 non-obese women matched for age, with similar hygiene habits, with no comorbidities and not taking any medication known to affect saliva secretion were analysed. In the validation group, a cohort of no-preselected 81 individuals (34 obese) were analysed.

RESULTS

Individuals with obesity had significantly higher salivary concentrations of several cytokines and adipokines, of which TNF-R1, serpin A12 and PAI-1 were identified as parameters discriminating between obese and non-obese subjects with the highest sensitivity and specificity.

CONCLUSIONS

Obesity per se leads to distinct changes in the concentration of several parameters in saliva. These findings may have diagnostic implications for distinguishing the effects of obesity and obesity-linked comorbidities on oral health.

Correlation between HSP-72 Expression and IL-8 Secretion in Human Mesothelial Cells

Background

Cytotoxicity of peritoneal dialysis fluid (PDF) and peritoneal inflammation are currently regarded as the two major culprits for chronic mesothelial injury and peritoneal membrane failure. In this study, we correlated induction of HSP-72, as a marker of the cellular stress response, to secretion of IL-8, as a marker for pro-inflammatory cytokines, in mesothelial cells upon sublethal PDF exposure.

Methods

Primary omental cell cultures of human mesothelial cells were subjected to sublethal PDF exposure times (CAPD2, Fresenius, Germany). At the end of a 24 hour recovery period, induction of HSP-72 in the cell homogenate and IL-8 secretion in the supernatant was assessed by immunodensitometry and ELISA, respectively.

Results

PDF exposure times from 15 min to 60 min resulted in progressively increased HSP-72 expression levels (267 vs 320 vs 419% of controls, p<0.05 vs controls) as well as increased IL-8 secretion (323 vs 528 vs 549% of controls, p<0.05 vs controls) with full cell viability (MTT unchanged to control). HSP-72 expression was statistically significantly correlated with IL-8 secretion. Conclusions: The significant correlation between HSP-72 expression and IL-8 secretion suggests that the regulation of pro-inflammatory pathways in mesothelial cells exposed to PDF may represent an integral part of their stress response. Future studies to investigate the cellular regulatory mechanism involved are warranted.

Do medical students adhere to advice regarding a healthy lifestyle? A pilot study of BMI and some aspects of lifestyle in medical students in Poland

BACKGROUND

The components of lifestyle of medical students, with comprehensive reporting of their physical activity and drinking and eating behavior, are rarely evaluated. Being overweight (increased body mass index - BMI) is associated with health problems, an unhealthy lifestyle (inadequate sleep, diet and exercise) being implicated.

OBJECTIVES

The aim was to determine if there were discrepancies between assessments of actual lifestyle and advice regarding the principles of a healthy lifestyle.

MATERIAL AND METHODS

The relationship between lifestyle and BMI was investigated in 270 medical students (158 females, 112 males) who answered a questionnaire about aspects of their lifestyle.

RESULTS

The mean ±SD BMI in males (23.41 ±0.25kg/m2) was significantly higher than in females (20.52 ±0.16kg/m2). Many aspects of lifestyle differed significantly with gender, including sleep habits, number of meals eaten, types of food eaten (fast food, amounts of fresh fruit and vegetables, sweets, etc.) and alcohol consumption, males generally having less healthy lifestyles. After correcting the associations between BMI and lifestyle factors for gender, one main finding was a positive association between BMI and alcohol intake, BMI rising by 0.014 kg/m2/g alcohol intake per week.

CONCLUSIONS

These results show clear differences between actual and advised lifestyle with regard to many aspects of sleep, food and fluid intake, and exercise. Most students, particularly males, had not adopted a healthy lifestyle. Possible future problems associated with this require more emphasis.

There is no difference in outcome between laparoscopic and open surgery for rectal cancer: a systematic review and meta-analysis on short- and long-term oncologic outcomes

Background

Until recently there has been little data available about long-term outcomes of laparoscopic rectal cancer surgery. But new randomized controlled trials regarding laparoscopic colorectal surgery have been published. The aim of this study was to compare the short- and long-term oncologic outcomes of laparoscopy and open surgery for rectal cancer through a systematic review of the literature and a meta-analysis of relevant RCTs.

Methods

A systematic review of Medline, Embase and the Cochrane library from January 1966 to October 2016 with a subsequent meta-analysis was performed. Only randomized controlled trials with data on circumferential resection margins were included. The primary outcome was the status of circumferential resection margins. Secondary outcomes included lymph node yield, distal resection margins, disease-free and overall survival rates for 3 and 5 years and local recurrence rates.

Results

Eleven studies were evaluated, involving a total of 2018 patients in the laparoscopic group and 1526 patients in the open group. The presence of involved circumferential margins was reported in all studies. There were no statistically significant differences in the number of positive circumferential margins between the laparoscopic group and open group, RR 1.16, 95% CI 0.89–1.50 and no significant differences in involvement of distal margins (RR 1.13 95% CI 0.35–3.66), completeness of mesorectal excision (RR 1.22, 95% CI 0.82–1.82) or number of harvested lymph nodes (mean difference = −0.01, 95% CI −0.89 to 0.87). Disease-free survival rates at 3 and 5 years were not different (p = 0.26 and p = 0.71 respectively), and neither were overall survival rates (p = 0.19 and p = 0.64 respectively), nor local recurrence rates (RR 0.88, 95% CI 0.63–1.23).

Conclusions

Laparoscopic surgery for rectal cancer is associated with similar short-term and long-term oncologic outcomes compared to open surgery. The oncologic quality of extracted specimens seems comparable regardless of the approach used.

Electronic supplementary material

The online version of this article (doi:10.1007/s10151-017-1662-4) contains supplementary material, which is available to authorized users.