Mitochondria-targeted hydrogen sulfide donor reduces fatty liver and obesity in mice fed a high fat diet by inhibiting de novo lipogenesis and inflammation via mTOR/SREBP-1 and NF-κB signaling pathways.

Metabolic diseases that include obesity and metabolic-associated fatty liver disease (MAFLD) are a rapidly growing worldwide public health problem. The pathogenesis of MAFLD includes abnormally increased lipogenesis, chronic inflammation, and mitochondrial dysfunction. Mounting evidence suggests that hydrogen sulfide (H2S) is an important player in the liver, regulating lipid metabolism and mitochondrial function. However, direct delivery of H2S to mitochondria has not been investigated as a therapeutic strategy in obesity-related metabolic disorders. Therefore, our aim was to comprehensively evaluate the influence of prolonged treatment with a mitochondria sulfide delivery molecule (AP39) on the development of fatty liver and obesity in a high fat diet (HFD) fed mice. Our results demonstrated that AP39 reduced hepatic steatosis in HFD-fed mice, which was corresponded with decreased triglyceride content. Furthermore, treatment with AP39 downregulated pathways related to biosynthesis of unsaturated fatty acids, lipoprotein assembly and PPAR signaling. It also led to a decrease in hepatic de novo lipogenesis by downregulating mTOR/SREBP-1/SCD1 pathway. Moreover, AP39 administration alleviated obesity in HFD-fed mice, which was reflected by reduced weight of mice and adipose tissue, decreased leptin levels in the plasma and upregulated expression of adipose triglyceride lipase in epididymal white adipose tissue (eWAT). Finally, AP39 reduced inflammation in the liver and eWAT measured as the expression of proinflammatory markers (Il1b, Il6, Tnf, Mcp1), which was due to downregulated mTOR/NF-κB pathway. Taken together, mitochondria-targeted sulfide delivery molecules could potentially provide a novel therapeutic approach to the treatment/prevention of obesity-related metabolic disorders.

Whole-Exome Screening and Analysis of Signaling Pathways in Multiple Endocrine Neoplasia Type 1 Patients with Different Outcomes: Insights into Cellular Mechanisms and Possible Functional Implications.

Multiple endocrine neoplasia type 1 (MEN1) is a syndrome characterized by tumors in multiple organs. Although being a dominantly inherited monogenic disease, disease phenotypes are unpredictable and differ even among members of the same family. There is growing evidence for the role of modifier genes in the alteration of the course of this disease. However, genome-wide screening data are still lacking. In our study, we addressed the different outcomes of the disease, focusing on pituitary and adrenocortical tumors. By means of exome sequencing we identified the affected signaling pathways that segregated with those symptoms. Most significantly, we identified damaging alterations in numerous structural genes responsible for cell adhesion and migration. Additionally, in the case of pituitary tumors, genes related to neuronal function, survival, and morphogenesis were repeatedly identified, while in patients with adrenocortical tumors, TLR10, which is involved in the regulation of the innate immunity, was commonly modified. Our data show that using exome screening, it is possible to find signatures which correlate with the given clinical MEN1 outcomes, providing evidence that studies addressing modifier effects in MEN1 are reasonable.

Alkaline Phosphatase Relieves Colitis in Obese Mice Subjected to Forced Exercise via Its Anti-Inflammatory and Intestinal Microbiota-Shaping Properties.

Intestinal alkaline phosphatase (IAP) is an enzyme that plays a protective role in the gut. This study investigated the effect of IAP treatment on experimental colitis in mice subjected to forced exercise on a high-fat diet. C57BL/6 mice with TNBS colitis were fed a high-fat diet and subjected to forced treadmill exercise with or without IAP treatment. Disease activity, oxidative stress, inflammatory cytokines, and gut microbiota were assessed. Forced exercise exacerbated colitis in obese mice, as evidenced by increased disease activity index (DAI), oxidative stress markers, and proinflammatory adipokines and cytokines. IAP treatment significantly reduced these effects and promoted the expression of barrier proteins in the colonic mucosa. Additionally, IAP treatment altered the gut microbiota composition, favoring beneficial Verrucomicrobiota and reducing pathogenic Clostridia and Odoribacter. IAP treatment ameliorates the worsening effect of forced exercise on murine colitis by attenuating oxidative stress, downregulating proinflammatory biomarkers, and modulating the gut microbiota. IAP warrants further investigation as a potential therapeutic strategy for ulcerative colitis.

Substrate Affinity Is Not Crucial for Therapeutic L-Asparaginases: Antileukemic Activity of Novel Bacterial Enzymes.

L-asparaginases are used in the treatment of acute lymphoblastic leukemia. The aim of this work was to compare the antiproliferative potential and proapoptotic properties of novel L-asparaginases from different structural classes, viz. EcAIII and KpAIII (class 2), as well as ReAIV and ReAV (class 3). The EcAII (class 1) enzyme served as a reference. The proapoptotic and antiproliferative effects were tested using four human leukemia cell models: MOLT-4, RAJI, THP-1, and HL-60. The antiproliferative assay with the MOLT-4 cell line indicated the inhibitory properties of all tested L-asparaginases. The results from the THP-1 cell models showed a similar antiproliferative effect in the presence of EcAII, EcAIII, and KpAIII. In the case of HL-60 cells, the inhibition of proliferation was observed in the presence of EcAII and KpAIII, whereas the proliferation of RAJI cells was inhibited only by EcAII. The results of the proapoptotic assays showed individual effects of the enzymes toward specific cell lines, suggesting a selective (time-dependent and dose-dependent) action of the tested L-asparaginases. We have, thus, demonstrated that novel L-asparaginases, with a lower substrate affinity than EcAII, also exhibit significant antileukemic properties in vitro, which makes them interesting new drug candidates for the treatment of hematological malignancies. For all enzymes, the kinetic parameters (Km and kcat) and thermal stability (Tm) were determined. Structural and catalytic properties of L-asparaginases from different classes are also summarized.

In-Hospital Levels of Circulating MicroRNAs as Potential Predictors of Left Ventricular Remodeling Post-Myocardial Infarction.

Background and Objectives: Biochemical and molecular regulation of both adaptive and pathological responses of heart tissue to ischemic injury is widely investigated. However, it is still not fully understood. Several biomarkers are tested as predictors of left ventricle (LV) remodeling after myocardial infarction (MI). The aim of this study was to assess the relationship between selected microRNAs (miRNAs) and LV function and morphology in patients after MI. Materials and Methods: Selected miRNAs related to heart failure were assessed in the acute phase of MI: miR-150-3p, miR-21-5p, miR-19b-3p, miR-155-5p, miR-22-5p. Echocardiography with 3D imaging was performed at baseline and after 6 months. Remodeling was defined as >20% increase in LV end-diastolic volume, whereas reverse remodeling was defined as >10% reduction in LV end-systolic volume. Results: Eighty patients entered the registry. Remodeling occurred in 26% and reverse remodeling was reported in 51% of patients. In the presented study, none of the analyzed miRNAs were found to be a significant LV remodeling predictor. The observed correlations between miRNAs and other circulating biomarkers of myocardial remodeling were relatively weak. Conclusions: Our analysis does not demonstrate an association between the analyzed miRNAs and LV remodeling in patients with MI.

Profile of circulating extracellular vesicles microRNA correlates with the disease activity in granulomatosis with polyangiitis.

Granulomatosis with polyangiitis is a chronic systemic inflammation of small vessels characterized by circulating anti-proteinase 3 antibodies. MicroRNAs are short transcripts specifically inhibiting protein translation. Neutrophils can release extracellular vesicles (EVs). In this study, we characterized profile of microRNA trafficked by EVs in GPA. Fifty patients with GPA were enrolled in the study, 25 at acute phase and 25 in remission. EVs were isolated from the blood serum, characterized by their number, size distribution. Following unbiased screening for microRNA expression, differentially expressed candidates were measured by quantitative real-time PCR. Circulating DNA-myeloperoxidase complexes and apoptosis-related transcripts in peripheral blood neutrophils were quantified. We identified four differentially expressed microRNAs from EVs in granulomatosis with polyangiitis (GPA). MirRs-223-3p, 664a-3p, and 200b-3p were overexpressed and miR-769-5p suppressed in the disease. A distinction between GPA and healthy controls was the best for miR-223-3p, whereas miR-664a-3p discriminated between active vs. remission of GPA. Correct classification of the disease based on multivariate discriminant analysis was between 92% for acute phase and 85% for all study participants. Bioinformatics tools identified genes transcripts potentially targeted by the microRNAs belonging to pathways of focal adhesion, mTOR signaling and neutrophil extracellular traps formation. Two microRNAs positively correlating with the disease activity were involved in neutrophil extracellular traps formation and apoptosis inhibition. A comprehensive characteristics of microRNAs trafficked in bloodstream inside EVs correlates well with our understanding of the mechanisms of GPA and suggests the importance of EVs in progression of the disease.

Inhaled silica nanoparticles exacerbate atherosclerosis through skewing macrophage polarization towards M1 phenotype.

BACKGROUND AND AIMS: Exposure to environmental nanoparticles is related to the adverse impact on health, including cardiovascular system. Various forms of nanoparticles have been reported to interact with endothelium and induce inflammation. However, the potential role of nanoparticles in the pathogenesis of atherosclerosis and their mechanisms of action are still unclear. The aim of this study was to investigate the effect of two broadly used nanomaterials, which also occur in natural environment - silicon oxide (SiO2) and ferric oxide (Fe2O3) in the form of nanoparticles (NPs) - on the development of atherosclerosis. METHODS: We used apolipoprotein E-knockout mice exposed to silica and ferric oxide nanoparticles in a whole body inhalation chamber. RESULTS: Inhaled silica nanoparticles augmented the atherosclerotic lesions and increased the percentage of pro-inflammatory M1 macrophages in both the plaque and the peritoneum in apoE-/- mice. Exposure to ferric oxide nanoparticles did not enhance atherogenesis process, however, it caused significant changes in the atherosclerotic plaque composition (elevated content of CD68-positive macrophages and enlarged necrotic core accompanied by the decreased level of M1 macrophages). Both silica and ferric oxide NPs altered the phenotype of T lymphocytes in the spleen by promoting polarization towards Th17 cells. CONCLUSIONS: Exposure to silica and ferric oxide nanoparticles exerts impact on atherosclerosis development and plaque composition. Pro-atherogenic abilities of silica nanoparticles are associated with activation of pro-inflammatory macrophages.

The Combination of Intestinal Alkaline Phosphatase Treatment with Moderate Physical Activity Alleviates the Severity of Experimental Colitis in Obese Mice via Modulation of Gut Microbiota, Attenuation of Proinflammatory Cytokines, Oxidative Stress Biomarkers and DNA Oxidative Damage in Colonic Mucosa.

Inflammatory bowel diseases (IBD) are commonly considered as Crohn's disease and ulcerative colitis, but the possibility that the alterations in gut microbiota and oxidative stress may affect the course of experimental colitis in obese physically exercising mice treated with the intestinal alkaline phosphatase (IAP) has been little elucidated. Mice fed a high-fat-diet (HFD) or normal diet (ND) for 14 weeks were randomly assigned to exercise on spinning wheels (SW) for 7 weeks and treated with IAP followed by intrarectal administration of TNBS. The disease activity index (DAI), grip muscle strength test, oxidative stress biomarkers (MDA, SOD, GSH), DNA damage (8-OHdG), the plasma levels of cytokines IL-2, IL-6, IL-10, IL-12p70, IL-17a, TNF-α, MCP-1 and leptin were assessed, and the stool composition of the intestinal microbiota was determined by next generation sequencing (NGS). The TNBS-induced colitis was worsened in obese sedentary mice as manifested by severe colonic damage, an increase in DAI, oxidative stress biomarkers, DNA damage and decreased muscle strength. The longer running distance and weight loss was observed in mice given IAP or subjected to IAP + SW compared to sedentary ones. Less heterogeneous microbial composition was noticed in sedentary obese colitis mice and this effect disappeared in IAP + SW mice. Absence of Alistipes, lower proportion of Turicibacter, Proteobacteria and Faecalibacterium, an increase in Firmicutes and Clostridium, a decrease in oxidative stress biomarkers, 8-OHdG content and proinflammatory cytokines were observed in IAP + SW mice. IAP supplementation in combination with moderate physical activity attenuates the severity of murine colitis complicated by obesity through a mechanism involving the downregulation of the intestinal cytokine/chemokine network and oxidative stress, the modulation of the gut microbiota and an improvement of muscle strength.

Biocompatibility testing of composite biomaterial designed for a new petal valve construction for pulsatile ventricular assist device.

This paper presents the results of biocompatibility testing performed on several biomaterial variants for manufacturing a newly designed petal valve intended for use in a pulsatile ventricular assist device or blood pump. Both physical vapor deposition (PVD) and plasma-enhanced chemical vapor deposition (PECVD) were used to coat titanium-based substrates with hydrogenated tetrahedral amorphous carbon (ta-C:H) or amorphous hydrogenated carbon (a-C:H and a-C:H, N). Experiments were carried out using whole human blood under arterial shear stress conditions in a cone-plate analyzer (ap. 1800 1/s). In most cases, tested coatings showed good or very good haemocompatibility. Type a-C:H, N coating proved to be superior in terms of activation, risk of aggregation, and the effects of generating microparticles of apoptotic origin, and also demonstrated excellent mechanical properties. Therefore, a-C:H, N coatings were selected for further in vivo studies. In vivo animal studies were carried out according to the ISO 10993 standard. Intradermal reactivity was assessed in three rabbits and sub-acute toxicity and local effects after implantation were examined in 12 rabbits. Based on postmortem examination, no organ failure or wound tissue damage occurred during the required period of observation. In summary, our investigations demonstrated high biocompatibility of the biomaterials in relation to thrombogenicity, toxicity, and wound healing. Prototypes of the petal valves were manufactured and mounted on the pulsatile ventricular assist device. Hydrodynamic features and impact on red blood cells (hemolysis) as well as coagulation (systemic thrombogenicity) were assessed in whole blood.

The Anti-Atherosclerotic Action of FFAR4 Agonist TUG-891 in ApoE-Knockout Mice Is Associated with Increased Macrophage Polarization towards M2 Phenotype.

Background: Over the past few years, a better understanding of the biology of G-protein coupled receptors (GPRs) has led to the identification of several receptors as novel targets for free fatty acids (FFAs). FFAR4 has received special attention in the context of chronic inflammatory diseases, including atherosclerosis, obesity and NAFLD, through to its anti-inflammatory effect. Methods: The present study investigates the influence of prolonged treatment with TUG-891-FFAR4 agonist on the development of atherosclerosis plaque in apoE-knockout mice, using morphometric and molecular methods. Results: TUG-891 administration has led to the reduction of atherosclerotic plaque size and necrotic cores in an apoE-knockout mice model. TUG-891-treated mice were administered subcutaneously at a dose of 20 mg/kg three times a week for 4 months. The FFAR4 agonist reduced the content of pro-inflammatory M1-like macrophages content in atherosclerotic plaques, as evidenced by immunohistochemical phenotyping and molecular methods. In atherosclerotic plaque, the population of smooth muscle cells increased as evidenced by α-SMA staining. We observed changes in G-CSF and eotaxin markers in the plasma of mice; changes in the levels of these markers in the blood may be related to macrophage differentiation. Importantly, we observed a significant increase in M2-like macrophage cells in atherosclerotic plaque and peritoneum. Conclusions: Prolonged administration of TUG-891 resulted in significant amelioration of atherogenesis, providing evidence that the strategy based on macrophage phenotype switching toward an M2-like activation state via stimulation of FFAR4 receptor holds promise for a new approach in the prevention or treatment of atherosclerosis.

LTB4 and 5-oxo-ETE from extracellular vesicles stimulate neutrophils in granulomatosis with polyangiitis.

Activation of neutrophils is an important mechanism in the pathology of granulomatosis with polyangiitis (GPA). In this study, we evaluated whether extracellular vesicles (EVs) circulating in the plasma of GPA patients could contribute to this process. EVs from the plasma of GPA patients in the active stage of the disease (n = 10) and healthy controls (n = 10) were isolated by ultracentrifugation and characterized by flow cytometry (CD63, CD8) and nanoparticle tracking analysis. Targeted oxylipin lipidomics of EVs was performed by HPLC-MS/MS. EV/oxylipin-induced neutrophil extracellular traps (NETs) were analyzed by confocal microscopy, and released double-stranded DNA (dsDNA) was quantified by PicoGreen fluorescent dye. Reactive oxygen species (ROS) production and neutrophils' EV binding/uptake were evaluated by flow cytometry. Brief priming with granulocyte-macrophage colony-stimulating factor was required for EV-mediated ROS production and dsDNA release. It was observed that priming also increased EV binding/uptake by neutrophils only for EVs from GPA patients. EVs from GPA patients had higher concentrations of leukotriene (LT)B4 and 5-oxo-eicosatetraenoic acid (5-oxo-ETE) as compared with EVs from healthy controls. Moreover, neutrophils stimulated with LTB4 or 5-oxo-ETE produced ROS and released dsDNA in a concentration-dependent manner. These results reveal the potential role of EVs containing oxylipin cargo on ROS production and NET formation by activated neutrophils.

Effect of Acute Sprint Exercise on Myokines and Food Intake Hormones in Young Healthy Men.

Physical exercise is known to influence hormonal mediators of appetite, but the effect of short-term maximal intensity exercise on plasma levels of appetite hormones and cytokines has been little studied. We investigated the effect of a 30 s Wingate Test, followed by a postprandial period, on appetite sensations, food intake, and appetite hormones. Twenty-six physically active young males rated their subjective feelings of hunger, prospective food consumption, and fatigue on visual analogue scales at baseline, after exercise was completed, and during the postprandial period. Blood samples were obtained for the measurement of nesfatin-1, ghrelin, leptin, insulin, pancreatic polypeptide (PP), human growth factor (hGH) and cytokine interleukin-6 (IL-6), irisin and plasma lactate concentrations, at 30 min before exercise, immediately (210 s) after exercise, and 30 min following a meal and at corresponding times in control sedentary males without ad libitum meal intake, respectively. Appetite perceptions and food intake were decreased in response to exercise. Plasma levels of irisin, IL-6, lactate, nesfatin-1 and ghrelin was increased after exercise and then it was returned to postprandial/control period in both groups. A significant rise in plasma insulin, hGH and PP levels after exercise was observed while meal intake potentiated this response. In conclusion, an acute short-term fatiguing exercise can transiently suppress hunger sensations and food intake in humans. We postulate that this physiological response involves exercise-induced alterations in plasma hormones and the release of myokines such as irisin and IL-6, and supports the notion of existence of the skeletal muscle-brain-gut axis. Nevertheless, the detailed relationship between acute exercise releasing myokines, appetite sensations and impairment of this axis leading to several diseases should be further examined.

Molecular Profile of Barrett's Esophagus and Gastroesophageal Reflux Disease in the Development of Translational Physiological and Pharmacological Studies.

Barrett's esophagus (BE) is a premalignant condition caused by gastroesophageal reflux disease (GERD), where physiological squamous epithelium is replaced by columnar epithelium. Several in vivo and in vitro BE models were developed with questionable translational relevance when implemented separately. Therefore, we aimed to screen Gene Expression Omnibus 2R (GEO2R) databases to establish whether clinical BE molecular profile was comparable with animal and optimized human esophageal squamous cell lines-based in vitro models. The GEO2R tool and selected databases were used to establish human BE molecular profile. BE-specific mRNAs in human esophageal cell lines (Het-1A and EPC2) were determined after one, three and/or six-day treatment with acidified medium (pH 5.0) and/or 50 and 100 µM bile mixture (BM). Wistar rats underwent microsurgical procedures to generate esophagogastroduodenal anastomosis (EGDA) leading to BE. BE-specific genes (keratin (KRT)1, KRT4, KRT5, KRT6A, KRT13, KRT14, KRT15, KRT16, KRT23, KRT24, KRT7, KRT8, KRT18, KRT20, trefoil factor (TFF)1, TFF2, TFF3, villin (VIL)1, mucin (MUC)2, MUC3A/B, MUC5B, MUC6 and MUC13) mRNA expression was assessed by real-time PCR. Pro/anti-inflammatory factors (interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, tumor necrosis factor α, interferon γ, granulocyte-macrophage colony-stimulating factor) serum concentration was assessed by a Luminex assay. Expression profile in vivo reflected about 45% of clinical BE with accompanied inflammatory response. Six-day treatment with 100 µM BM (pH 5.0) altered gene expression in vitro reflecting in 73% human BE profile and making this the most reliable in vitro tool taking into account two tested cell lines. Our optimized and established combined in vitro and in vivo BE models can improve further physiological and pharmacological studies testing pathomechanisms and novel therapeutic targets of this disorder.

Skewing toward Treg and Th2 responses is a characteristic feature of sustained remission in ANCA-positive granulomatosis with polyangiitis.

The objective of our study was to evaluate the T-helper (Th) and regulatory T (Treg) cell profile in ANCA-positive granulomatosis with polyangiitis (GPA) and its relation to disease activity. In a prospective study, we studied two groups of GPA patients: (i) disease flare (active-GPA, BVAS>6, n = 19), (ii) sustained remission (≥ 1-year prior enrollment, inactive-GPA, BVAS = 0, n = 18). 24 age-sex matched healthy subjects served as controls. Active-GPA patients were followed for 6 months and reevaluated during remission (early remission; n = 13). We analyzed subsets of Th-cells (flow cytometry), production of signature cytokines by in vitro stimulated lymphocytes, and broad spectrum of serum cytokines (Luminex). In all GPA patients we observed expansion of effector Th17 cells, and increased production of IL-17A by in vitro stimulated T cells, as compared to controls. Disease flare was characterized by marked reduction in Treg cells, whereas in sustained remission we showed expansion of both Treg and Th2 subset. Finally, analyzing the cytokine profile, we identified CCL23 and LIGHT, as potential biomarkers of active disease. We conclude that in GPA, expansion of Treg and Th2 lymphocytes in parallel to increased Th17 response is a characteristic feature of sustained remission. In contrast, Treg cells are markedly decreased in disease flare.

Colorectal cancer-derived microvesicles modulate differentiation of human monocytes to macrophages.

BACKGROUND: Tumour-derived microvesicles (TMVs) are important players in tumour progression, modulating biological activity of immune cells e.g. lymphocytes, monocytes and macrophages. This phenomenon is particularly interesting in the progression of colon cancer, as macrophages in this type of tumour are relevant for the recovery processes. In the present study, the role of colon cancer cell-derived microvesicles in monocyte differentiation and activity profile (polarization) was investigated. METHODS: Monocyte-derived macrophages (MDM) were differentiated in vitro in the presence of TMVs obtained from colon cancer: Caco-2, SW620, LoVo or SW480 cell lines and analysed according to their morphology and biological functions, as defined by cytokine secretion, reactive oxygen intermediate (ROI) production and cytotoxic activity against respective colon cancer cells. RESULTS: Monocytes differentiated with TMVs exhibited morphological and phenotypical characteristics of macrophages. An early contact (beginning with the first day of the in vitro culture) of monocytes with TMVs resulted in increased IL-10 secretion and only slightly elevated TNF release. Early, or prolonged contact resulted in low ROI production and low cytotoxicity against tumour cells. On the other hand, late contact of MDM with TMVs, stimulated MDM to significant TNF and IL-12 secretion, ROI production and enhanced cytotoxicity against tumour cells in vitro. In addition, differences in MDM response to TMVs from different cell lines were observed (according to cytokine secretion, ROI production and cytotoxicity against tumour cells in vitro). Biological activity, STATs phosphorylation and microRNA profiling of MDMs indicated differences in their polarization/activation status which may suggest mixed polarization type M1/M2 with the predominance of proinflammatory cells after late contact with TMVs. CONCLUSIONS: Macrophage activity (polarization status) may be regulated by contact with not only tumour cells but also with TMVs. Their final polarization status depends on the contact time, and probably on the vesicle "cargo", as signified by the distinct impact of TMVs which enabled the switching of MDM maturation to regulatory macrophages.

Neutrophil-related and serum biomarkers in granulomatosis with polyangiitis support extracellular traps mechanism of the disease.

OBJECTIVES: Granulomatosis with polyangiitis (GPA) is an autoimmune disease with still unknown etiology. Recent studies indicate that neutrophils extra-cellular traps participate in the pathophysiology of GPA. This study investigates the levels of circulating NET formation markers and neutrophil-platelet interaction in patients with GPA. METHODS: We enrolled 40 GPA patients (20 in the active stage of the disease and 20 in remission). Twenty sex- and age-matched healthy subjects served as a control group. Serum/plasma levels of serine proteases, and histone-, myeloperoxidase-, proteinase-3 DNA complexes and sP-selectin were measured using ELISA or Luminex assays. Circulating platelet-neutrophil aggregates and neutrophils activation markers expression was measured by flow cytometry. RESULTS: Patients in active stage of GPA had higher circulating levels of serine proteases, DNA-histone and myeloperoxidase -DNA complexes. In addition, platelet-neutrophil aggregates and sP-selectin were also elevated in this group. Platelet-neutrophil aggregates and myeloperoxidase -DNA complexes correlated positively with the disease activity score (BVAS). CONCLUSIONS: NETs production and activation of platelets in GPA is supported by elevated myeloperoxidase-DNA complexes and platelet-neutrophil aggregates correlating positively with the disease activity score. This mechanism justifies laboratory measurements of myeloperoxidase-DNA complexes and plasma sP-selectin as biomarkers for studying GPA activity.

Hydrogen Sulfide and Carbon Monoxide Protect Gastric Mucosa Compromised by Mild Stress Against Alendronate Injury.

BACKGROUND: Alendronate is an inhibitor of osteoclast-mediated bone resorption, but its clinical utility is limited due to gastrointestinal complications including bleeding erosions. AIMS: We studied whether potent vasodilators hydrogen sulfide (H2S) and carbon monoxide (CO) can protect against alendronate-induced gastric lesions in rats exposed to mild stress. METHODS: Three series (A, B, and C) of Wistar rats received alendronate (150-700 mg/kg i.g., series A) with or without NaHS (5 mg/kg), H2S donor or CORM-2 (5 mg/kg) releasing CO administered i.g. 30 min before alendronate administration (series B) in rats exposed for 3 days before alendronate administration to mild stress (series C). The area of gastric lesions was assessed by planimetry, the gastric blood flow (GBF) was determined by H2-gas clearance technique, and H2S production via CSE/CBS/3-MST activity and the gastric expression of HO-1, HO-2, HIF-1α, NF-κB, iNOS, COX-2, IL-1ß, TNF-α, GPx-1 and SOD-2 were analyzed by qPCR or Western blot. RESULTS: Alendronate dose-dependently produced gastric mucosal lesions and significantly decreased GBF, and these effects were exacerbated by mild stress. NaHS and CORM-2 significantly reduced the alendronate-induced gastric lesions in non-stressed and stressed animals, but only NaHS but not CORM-2 raised H2S production. NaHS and CORM-2 inhibited gastric expression of HIF-1α protein and HO-1, HIF-1α, NF-κB, COX-2, iNOS, IL-1ß, TNF-α mRNAs but failed to affect those of HO-2, GPx-1, and SOD-2. CONCLUSION: Both H2S and CO released from their donors, NaHS and CORM-2, protect gastric mucosa compromised by stress against alendronate-induced gastric damage via mechanism involving downregulation of HIF-1α, NF-κB and proinflammatory factors COX-2, iNOS, IL-1ß, and TNF-α.

The Protective Role of Carbon Monoxide (CO) Produced by Heme Oxygenases and Derived from the CO-Releasing Molecule CORM-2 in the Pathogenesis of Stress-Induced Gastric Lesions: Evidence for Non-Involvement of Nitric Oxide (NO).

Carbon monoxide (CO) produced by heme oxygenase (HO)-1 and HO-2 or released from the CO-donor, tricarbonyldichlororuthenium (II) dimer (CORM-2) causes vasodilation, with unknown efficacy against stress-induced gastric lesions. We studied whether pretreatment with CORM-2 (0.1-10 mg/kg oral gavage (i.g.)), RuCl3 (1 mg/kg i.g.), zinc protoporphyrin IX (ZnPP) (10 mg/kg intraperitoneally (i.p.)), hemin (1-10 mg/kg i.g.) and CORM-2 (1 mg/kg i.g.) combined with N(G)-nitro-l-arginine (l-NNA, 20 mg/kg i.p.), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 mg/kg i.p.), indomethacin (5 mg/kg i.p.), SC-560 (5 mg/kg i.g.), and celecoxib (10 mg/kg i.g.) affects gastric lesions following 3.5 h of water immersion and restraint stress (WRS). Gastric blood flow (GBF), the number of gastric lesions and gastric CO and nitric oxide (NO) contents, blood carboxyhemoglobin (COHb) level and the gastric expression of HO-1, HO-2, hypoxia inducible factor 1α (HIF-1α), tumor necrosis factor α (TNF-α), cyclooxygenase (COX)-2 and inducible NO synthase (iNOS) were determined. CORM-2 (1 mg/kg i.g.) and hemin (10 mg/kg i.g.) significantly decreased WRS lesions while increasing GBF, however, RuCl3 was ineffective. The impact of CORM-2 was reversed by ZnPP, ODQ, indomethacin, SC-560 and celecoxib, but not by l-NNA. CORM-2 decreased NO and increased HO-1 expression and CO and COHb content, downregulated HIF-1α, as well as WRS-elevated COX-2 and iNOS mRNAs. Gastroprotection by CORM-2 and HO depends upon CO's hyperemic and anti-inflammatory properties, but is independent of NO.

Neutrophil MiRNA-128-3p is Decreased During Active Phase of Granulo-matosis with Polyangiitis.

Granulomatosis with polyangiitis is a rare chronic inflammatory disease. In this multisystem autoimmune disorder neutrophils cause small vessels necrosis and infiltrate perivascular tissue to form granulomas. Progression of the disease is evaluated by the symptoms score and by a titer of anti-neutrophil cytoplasm antibodies. Despite glucocorticoid and immunosuppressive therapy, prognosis is complicated by chronic renal insufficiency, hearing loss and skin ulceration. In this preliminary study we tested the hypothesis that altered neutrophil expression of miRNAs can contribute to the cell activation, extracellular traps formation and decreased apoptosis. First we compared a profile of 728 miRNAs expressed in circulating neutrophils of patients with active disease and matched healthy donors. Subsequently, candidate miRNAs were quantified in neutrophils from 16 subjects with active disease, 16 asymptomatic patients at the remission and in 16 healthy controls. Out of 11 candidate miRNAs, only miR-128-3p was both biologically (relative quantity < 30% control or remission patients) and statistically (p<0.01) decreased in the cells during active stage of the disease. This miRNA correlated with a clinical score of the disease well. A set of 10 transcripts involved in the mechanism of the disease was quantified from the same neutrophils RNA. Relative expression of MMP9 was higher in neutrophils from the patients with active disease and correlated negatively with miR-128-3p. The opposite finding was present for MTA1 transcripts. Despite surprisingly scarce changes in the expression of neutrophil miRNAs, miR-128-3p is the best candidate for deciphering etiology of granulomatosis with polyangiitis.

Exogenous asymmetric dimethylarginine (ADMA) in pathogenesis of ischemia-reperfusion-induced gastric lesions: interaction with protective nitric oxide (NO) and calcitonin gene-related peptide (CGRP).

Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) synthesis inhibitor and pro-inflammatory factor. We investigated the role of ADMA in rat gastric mucosa compromised through 30 min of gastric ischemia (I) and 3 h of reperfusion (R). These I/R animals were pretreated with ADMA with or without the combination of L-arginine, calcitonin gene-related peptide (CGRP) or a small dose of capsaicin, all of which are known to afford protection against gastric lesions, or with a farnesoid X receptor (FXR) agonist, GW 4064, to increase the metabolism of ADMA. In the second series, ADMA was administered to capsaicin-denervated rats. The area of gastric damage was measured with planimetry, gastric blood flow (GBF) was determined by H2-gas clearance, and plasma ADMA and CGRP levels were determined using ELISA and RIA. ADMA significantly increased I/R-induced gastric injury while significantly decreasing GBF, the luminal NO content, and the plasma level of CGRP. This effect of ADMA was significantly attenuated by pretreatment with CGRP, L-arginine, capsaicin, or a PGE2 analogue. In GW4064 pretreated animals, the I/R injury was significantly reduced and this effect was abolished by co-treatment with ADMA. I/R damage potentiated by ADMA was exacerbated in capsaicin-denervated animals with a further reduction of CGRP. Plasma levels of IL-10 were significantly decreased while malonylodialdehyde (MDA) and plasma TNF-α contents were significantly increased by ADMA. In conclusion, ADMA aggravates I/R-induced gastric lesions due to a decrease of GBF, which is mediated by a fall in NO and CGRP release, and the enhancement of lipid peroxidation and its pro-inflammatory properties.