Assessment of EN-RAGE, sRAGE, and its isoforms: cRAGE, esRAGE in obese patients treated by moderate caloric restriction combined with physical activity conducted in hospital condition.

BACKGROUND: AGEs, their receptor (RAGE), and the extracellular newly identified receptor for AGEs product-binding protein (EN-RAGE) are implicated in the pathogenesis of inflammation. AIM: We analyzed serum EN-RAGE, soluble RAGE (sRAGE), and their isoforms: endogenous secretory - esRAGE and cleaved - cRAGE concentrations in lean controls (n = 74) and in patients with obesity (n = 71) treated for three weeks with moderate calorie restriction (CR) combined with physical activity in a hospital condition. METHODS: Using the ELISA method, serum sRAGE, esRAGE, and EN-RAGE were measured before and after CR. RESULTS: The serum level of sRAGE and esRAGE in patients with obesity was lower than that in non-obese individuals, contrary to cRAGE. EN-RAGE concentration was about three times higher in obese patients. Gradually, a rise in BMI resulted in sRAGE, esRAGE reduction, and EN-RAGE increase. The sRAGE concentration was sex-dependent, indicating a higher value in lean men. A moderate negative correlation was observed between BMI and all RAGE isoforms, whereas EN-RAGE displays a positive correlation. CR resulted in an expected decrease in anthropometric, metabolic, and proinflammatory parameters and EN-RAGE, but no RAGE isoforms. The ratio EN-RAGE/sRAGE was higher in obese humans than in control and was not modified by CR. CONCLUSION: Obesity decreases sRAGE and esRAGE and increases EN-RAGE concentration. Moderate CR and physical activity by decreasing inflammation reduces EN-RAGE but is insufficient to increase sRAGE and esRAGE to the extent observed in lean patients. EN-RAGE instead of sRAGE could be helpful to indicate a better outcome of moderate dietary intervention in obese subjects.

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.

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.

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.

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.

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.

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.

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.

IL-6 Trans-Signaling Links Inflammation with Angiogenesis in the Peritoneal Membrane.

Vascular endothelial growth factor (VEGF) is implicated in the peritoneal membrane remodeling that limits ultrafiltration in patients on peritoneal dialysis (PD). Although the exact mechanism of VEGF induction in PD is unclear, VEGF concentrations in drained dialysate correlate with IL-6 levels, suggesting a link between these cytokines. Human peritoneal mesothelial cells (HPMCs), the main source of IL-6 and VEGF in the peritoneum, do not bear the cognate IL-6 receptor and are thus unable to respond to classic IL-6 receptor signaling. Here, we investigated whether VEGF release by HPMCs is controlled by IL-6 in combination with its soluble receptor (IL-6 trans-signaling). Although treatment with either IL-6 or soluble IL-6 receptor (sIL-6R) alone had no effect on VEGF production, stimulation of HPMCs with IL-6 in combination with sIL-6R promoted VEGF expression and secretion through a transcriptional mechanism involving STAT3 and SP4. Conditioned medium from HPMCs cultured with IL-6 and sIL-6R promoted angiogenic endothelial tube formation, which could be blocked by silencing SP4. In vivo, induction of peritoneal inflammation in wild-type and IL-6-deficient mice showed IL-6 involvement in the control of Sp4 and Vegf expression and new vessel formation, confirming the role of IL-6 trans-signaling in these processes. Taken together, these findings identify a novel mechanism linking IL-6 trans-signaling and angiogenesis in the peritoneal membrane.

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.

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-1ß-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.

No effect of anti-TNF-α treatment on serum IL-17 in patients with rheumatoid arthritis.

INTRODUCTION: Interleukin 17 (IL-17) and CC-chemokine ligand 20 (CCL20) are increasingly implicated in the pathogenesis of rheumatoid arthritis (RA). A correlation has been reported to exist between serum levels of IL-17 and CCL20 and the disease activity. However, such an effect has not been universally demonstrated. The aim of the present study was to investigate if serum levels of IL-17 and/or CCL20 reflect the disease activity and response to anti-TNF-α therapy in patients with RA. MATERIAL AND METHODS: Twenty-two RA patients qualified to receive anti-TNF-α treatment were prospectively assessed before and after 12 weeks of therapy. Serum concentrations of IL-17 and CCL20 were measured with high-sensitivity immunoassays. Disease activity was assessed by the 28-joint disease activity score (DAS28). RESULTS: Twelve weeks of therapy resulted in a satisfactory therapeutic response in the majority (91%) of patients (reflected both by clinical and standard biochemical criteria). However, serum concentrations of IL-17 and CCL20 did not change significantly over the course of therapy Moreover, they did not correlate with the disease activity, patient characteristics, and their response to therapy. CONCLUSIONS: Serum levels of IL-17 and CCL20 do not reflect changes in the clinical and biochemical status that occur in patients undergoing anti-TNF-α treatment for RA. The lack of such an association indicates that IL-17 signalling is not affected by anti-TNF-α therapy and is thus not critically involved in the disease pathogenesis.

Serum adiponectin as a predictor of laboratory response to anti-TNF-α therapy in rheumatoid arthritis.

INTRODUCTION: While adiponectin is typically viewed as an anti-inflammatory mediator, such an activity of adiponectin in rheumatoid arthritis (RA) is not so obvious. In the present study we examined whether serum levels of adiponectin reflect the clinical phenotype of RA patients and/or correlate with severity of the disease and the response to anti-TNF-α therapy. MATERIAL AND METHODS: Twenty-one female RA patients qualified to receive anti-TNF-α treatment were prospectively assessed before and after 12 weeks of therapy. Patients underwent full clinical and biochemical assessment. Disease activity was assessed by the Modified Disease Activity Scores (DAS28). Serum concentrations of adiponectin were measured with an immunoassay. The individuals were divided into two subgroups according to whether their baseline serum adiponectin was below or above the median value. The subgroups did not differ in basic demographic, anthropometric, and clinical parameters. RESULTS: Anti-TNF-α treatment resulted in a significant clinical (DAS28) improvement in patients from both subgroups, but no significant differences between basal and post-treatment serum adiponectin concentrations were observed. However, patients with higher baseline adiponectin experienced a significant and more pronounced improvement in laboratory parameters of inflammation (ESR, CRP, neutrophil count, neutrophil-to-lymphocyte ratio). CONCLUSIONS: It is possible that adiponectin exerts systemic anti-inflammatory effects independently of the local activity of RA.

Thy-1+/- fibroblast subsets in the human peritoneum.

Fibrotic thickening of the peritoneum develops in patients receiving peritoneal dialysis (PD) for renal failure. For unknown reasons, however, in some patients it progresses to extensive fibrosis that compromises dialysis capacity of the peritoneum. It is increasingly clear that fibroblasts display large heterogeneity not only between but also within tissues. Differential surface expression of thymocyte differentiation antigen 1 (Thy-1) has been shown to identify functionally distinct fibroblast subsets in several organs. Here, we isolated Thy-1+/- subsets of human peritoneal fibroblasts (HPFB) and analyzed them in terms of profibrotic myofibroblast features. In healthy individuals, Thy-1+ cells constituted ~45% of the HPFB population found in the greater omentum but were not detected in the parietal peritoneum. When propagated in culture and compared with Thy-1- cells, omentum-derived Thy-1+ HPFB consistently displayed an increased expression of α-smooth muscle actin, collagen I, and transforming growth factor-ß1. They also showed greater proliferation capacity and enhanced contractile properties. The number of Thy-1+ HPFB increased significantly in PD patients and made up more than 70 and 95% of all HPFB found in the omentum and parietal peritoneum, respectively. These data indicate that the expansion of Thy-1+ fibroblasts may contribute to fibrotic thickening of the peritoneal membrane during PD.

Biomarker research to improve clinical outcomes of peritoneal dialysis: consensus of the European Training and Research in Peritoneal Dialysis (EuTRiPD) network.

Peritoneal dialysis (PD) therapy substantially requires biomarkers as tools to identify patients who are at the highest risk for PD-related complications and to guide personalized interventions that may improve clinical outcome in the individual patient. In this consensus article, members of the European Training and Research in Peritoneal Dialysis Network (EuTRiPD) review the current status of biomarker research in PD and suggest a selection of biomarkers that can be relevant to the care of PD patients and that are directly accessible in PD effluents. Currently used biomarkers such as interleukin-6, interleukin-8, ex vivo-stimulated interleukin-6 release, cancer antigen-125, and advanced oxidation protein products that were collected through a Delphi procedure were first triaged for inclusion as surrogate endpoints in a clinical trial. Next, novel biomarkers were selected as promising candidates for proof-of-concept studies and were differentiated into inflammation signatures (including interleukin-17, M1/M2 macrophages, and regulatory T cell/T helper 17), mesothelial-to-mesenchymal transition signatures (including microRNA-21 and microRNA-31), and signatures for senescence and inadequate cellular stress responses. Finally, the need for defining pathogen-specific immune fingerprints and phenotype-associated molecular signatures utilizing effluents from the clinical cohorts of PD patients and "omics" technologies and bioinformatics-biostatistics in future joint-research efforts was expressed. Biomarker research in PD offers the potential to develop valuable tools for improving patient management. However, for all biomarkers discussed in this consensus article, the association of biological rationales with relevant clinical outcomes remains to be rigorously validated in adequately powered, prospective, independent clinical studies.

Association of endothelial proliferation with the magnitude of weight loss during calorie restriction.

OBJECTIVES: Substantial weight loss through intense dietary regimens is thought to ameliorate endothelial dysfunction in obesity. It is less clear whether similar improvements can be achieved with modest dietary interventions. This study aimed to identify the parameters of endothelial cell status in obesity that are affected by mild calorie restriction. METHODS: Human umbilical vein endothelial cells (EA.hy926 line) in culture were exposed pairwise to serum from 57 individuals with simple obesity (BMI > 30 kg/m(2)) collected before and after 8-week dietary intervention with energy deficit of 300-500 kcal/day. RESULTS: Analysis of endothelial transcriptome suggested that the intervention could impact on endothelial cell growth. Cell proliferation was measured with the MTT test and verified by [(3)H]-thymidine incorporation. The participants were categorized according to a change in proliferation over time. Significant decrease in endothelial cell proliferation correlated with the extent of weight loss in men, but not in women. This effect corresponded with changes in serum levels of leptin and adiponectin, but was not related to serum concentrations of several known angiogenic mediators (VEGF, MCP-1, TSP-1, MMP-9, angiopoietin-2). CONCLUSION: Direction and magnitude of changes in serum-induced endothelial cell proliferation identifies patients with the greatest weight loss in response to modest calorie restriction.

Preliminary observations on the association between serum IL-6 and hydration status and cardiovascular risk in patients treated with peritoneal dialysis.

INTRODUCTION: Systemic inflammation, as defined by elevated blood IL-6, is a strong independent predictor of peritoneal dialysis (PD) patient survival. The present study has aimed to determine whether there exists a particular "phenotype" associated with high systemic IL-6 that characterizes PD patients in terms of their fluid status and cardiac parameters. METHODS: Fifty-seven prevalent PD patients were classified according to serum concentrations of IL-6. The degree of overhydration was assessed by bioimpedance analysis (BIA). Echocardiography and serum concentrations of NT-proBNP and troponin T were used to assess cardiovascular risk. RESULTS: Patients with high serum IL-6 were older, more often diabetic, treated with PD for longer, and significantly more overhydrated. There was a significant correlation between serum IL-6, hydration status (r=0.38; p=0.002) and serum albumin (r=-0.35; p=0.009). Multivariate regression analysis confirmed a strong association of overhydration, hypoalbuminemia, and systemic IL-6 concentration. Patients with high IL-6 had significantly increased levels of both NT-proBNP (r=0.36; p=0.006) and TnT (r=0.50; p<0.001) in the absence of abnormalities in echocardiography. CONCLUSIONS: High systemic IL-6 identifies PD patients with increased cardiovascular risk that is significantly related to overhydration. Thus, the measurement of serum IL-6 may contribute to the more accurate assessment of cardiovascular status in patients undergoing PD.

Increased storage and secretion of phosphatidylcholines by senescent human peritoneal mesothelial cells.

BACKGROUND/AIMS: Human peritoneal mesothelial cells (HPMC) secrete phosphatidylcholines (PC) which form a lipid bilayer lining the peritoneum. They prevent frictions and adhesions and act as a barrier to the transport of water-soluble solutes while permitting water flux. PC may play an essential role in peritoneal integrity and function, the role of PD induced HPMC senescence on PC homeostasis, however, is unknown. METHODS: HPMC cell lines were isolated from four non-uremic patients. Expression of the three PC synthesis genes (rt-PCR), and cellular storage and secretion of PC (ESI-mass-spectrometry) were analyzed in young and senescent HPMC (>Hayflick-limit). RESULTS: Senescent cells displayed significantly altered morphology; flow cytometry demonstrated extensive staining for senescence-associated beta galactosidase. Nine different PC were detected in HPMC with palmitoyl-myristoyl phosphatidylcholine (PMPC) being most abundant. In senescent HPMC mRNA expression of the three key PC synthesis genes was 1.5-, 2.4- and 6-fold increased as compared to young HPMC, with the latter, phosphatidylcholine cytidylyltransferase, being rate limiting. Intracellular storage of the nine PC was 75-450 % higher in senescent vs. young HPMC, PC secretion rates were 100-300 % higher. Intracellular PC concentrations were not correlated with the PC secretion rates. Electron microscopy demonstrated lamellar bodies, the primary storage site of PC, in senescent but not in young cells. CONCLUSION: Senescent HPMC store and secrete substantially more PC than young cells. Our findings indicate a novel protective mechanism, which should counteract peritoneal damage induced by chronic exposure to PD fluids.

Activation of nuclear factor of activated T cells 5 in the peritoneal membrane of uremic patients.

Peritoneal inflammation and fibrosis are responses to the uremic milieu and exposure to hyperosmolar dialysis fluids in patients on peritoneal dialysis. Cells respond to high osmolarity via the transcription factor nuclear factor of activated T cells (NFAT5). In the present study, the response of human peritoneal fibroblasts to glucose was analyzed in vitro. Expression levels of NFAT5 and chemokine (C-C motif) ligand (CCL2) mRNA were quantified in peritoneal biopsies of five nonuremic control patients, five uremic patients before PD (pPD), and eight patients on PD (oPD) using real-time PCR. Biopsies from 5 control patients, 25 pPD patients, and 25 oPD patients were investigated using immunohistochemistry to detect the expression of NFAT5, CCL2, NF-κB p50, NF-κB p65, and CD68. High glucose concentrations led to an early, dose-dependent induction of NFAT5 mRNA in human peritoneal fibroblasts. CCL2 mRNA expression was upregulated by high concentrations of glucose after 6 h, but, most notably, a concentration-dependent induction of CCL2 was present after 96 h. In human peritoneal biopsies, NFAT5 mRNA levels were increased in uremic patients compared with nonuremic control patients. No significant difference was found between the pPD group and oPD group. CCL2 mRNA expression was higher in the oPD group. Immunohistochemistry analysis was consistent with the results of mRNA analysis. CD68-positive cells were significantly increased in the oPD group. In conclusion, uremia results in NFAT5 induction, which might promote early changes of the peritoneum. Upregulation of NFAT5 in PD patients is associated with NFκB induction, potentially resulting in the recruitment of macrophages.

Association of serum VEGF with clinical response to anti-TNFα therapy for Crohn's disease.

Down-regulation of immune-mediated angiogenesis seems to be an important mechanism in anti-tumor necrosis factor α (anti-TNFα) therapy for Crohn's disease (CD). However, it remains to be established whether the baseline pro-angiogenic activity as reflected by the level of vascular endothelial growth factor (VEGF) could be of predictive value for successful clinical outcome of such treatment. Here, the levels of serum VEGF and other crucial angiogenesis-regulating peptides were assessed before and after induction anti-TNFα therapy in CD patients, and in age- and sex-matched healthy controls. Clinical, endoscopic, and biochemical activity of CD was estimated in parallel. CD patients were divided into two subgroups, depending on baseline VEGF levels: a "low-VEGF" subgroup with VEGF levels similar to those detected in healthy people, and a "high-VEGF" subgroup with VEGF levels significantly increased. VEGF levels were found to significantly correlate with CD clinical activity. Compared to the "low-VEGF" subgroup, the reduction in CD clinical activity as assessed by Crohn's Disease Activity Index was significantly greater in "high-VEGF" patients both in absolute numbers, and as a percentage of pre-treatment values. Accordingly, the fraction of patients who did not respond adequately to treatment was significantly greater in the "low-VEGF" group. These data indicate that VEGF may serve as an additional marker of CD activity and that baseline VEGF levels can be helpful in predicting the efficacy of anti-TNFα therapy.