Despite their clinical effectiveness, a growing body of evidence has shown that many classes of antibiotics lead to mitochondrial dysfunction. Ceftriaxone and Rifaximin are first choice perioperative antibiotics in gastrointestinal surgery targeting fundamental processes of intestinal bacteria; however, may also have negative consequences for the host cells. In this study, we investigated their direct effect on mitochondrial functions in vitro, together with their impact on ileum, colon and liver tissue. Additionally, their impact on the gastrointestinal microbiome was studied in vivo, in a rat model. Rifaximin significantly impaired the oxidative phosphorylation capacity (OxPhos) and leak respiration in the ileal mucosa, in line with increased oxidative tissue damage and histological changes following treatment. Ceftriaxone prophylaxis led to similar changes in the colon mucosa. The composition and diversity of bacterial communities differed extensively in response to antibiotic pre-treatment. However, the relative abundances of the toxin producing species were not increased. We have confirmed the harmful effects of prophylactic doses of Rifaximin and Ceftriaxone on the intestinal mucosa and that these effects were related to the mitochondrial dysfunction. These experiments raise awareness of mitochondrial side effects of these antibiotics that may be of clinical importance when evaluating their adverse effects on bowel mucosa.

l -Alpha-glycerylphosphorylcholine (GPC) is a widely used food supplement. GPC has been shown to exert beneficial effects in several organs; however, the cardiac effects of GPC have yet to be investigated. The aim of the present study was therefore to map out the effects of GPC on cardiac myocytes, with or without ischemia–reperfusion insult. Neonatal rat cardiac myocytes were treated with GPC at 1, 10, 80, and 100 µM concentrations for 15 min, 3 h, or 24 h, respectively. Cell viability by calcein assay and the degree of oxidative stress by DHE (superoxide level) and H 2 DCF (total ROS accumulation) staining were measured. In separate experiments, cardiomyocytes were pre-treated with the optimal concentration of GPC for 3 h and then cells were exposed to 4 h of simulated ischemia followed by 2 h of reperfusion (SI/R). Cell viability was measured at the end of the SI/R protocol. In normoxic conditions, the 15-min and the 3-h GPC treatment did not affect cell viability, total ROS, and superoxide levels. Under SI/R conditions, the 3-h GPC treatment protected the cardiac myocytes from SI/R-induced cell death and did not alter the level of oxidative stress. The 24-h GPC treatment in normoxic conditions resulted in significant cell death and increased oxidative stress at each concentration. Here we provide the first evidence for the cytoprotective effect of short-term GPC treatment. However, long-term administration of GPC may exert cytotoxicity in a wide concentration range in cardiac myocytes. These results may draw attention to a comprehensive cardiac safety protocol for the testing of GPC.

Ryanodine receptors have an important role in the regulation of intracellular calcium levels in the nervous system and muscle. It has been described that ryanodine receptors influence keratinocyte differentiation and barrier homeostasis. Our goal was to examine the role of ryanodine receptors in the healing of full-thickness dermal wounds by means of in vitro and in vivo methods. The effect of ryanodine receptors on wound healing, microcirculation and inflammation was assessed in an in vivo mouse wound healing model, using skin fold chambers in the dorsal region, and in HaCaT cell scratch wound assay in vitro. SKH-1 mice were subjected to sterile saline (n = 36) or ryanodine receptor agonist 4-chloro-m-cresol (0.5 mM) (n = 42) or ryanodine receptor antagonist dantrolene (100 mu M) (n = 42). Application of ryanodine receptor agonist 4-chloro-m-cresol did not influence the studied parameters significantly, whereas ryanodine receptor antagonist dantrolene accelerated the wound closure. Inhibition of the calcium channel also increased the vessel diameters in the wound edges during the process of healing and increased the blood flow in the capillaries at all times of measurement. Furthermore, application of dantrolene decreased xanthine-oxidoreductase activity during the inflammatory phase of wound healing. Inhibition of ryanodine receptor-mediated effects positively influence wound healing. Thus, dantrolene may be of therapeutic potential in the treatment of wounds.

Understanding the molecular mechanisms inducing and regulating epithelial-to-mesenchymal transition (EMT) upon chronic intestinal inflammation is critical for understanding the exact pathomechanism of inflammatory bowel disease (IBD). The aim of this study was to determine the expression profile of TAM family receptors in an inflamed colon. For this, we used a rat model of experimental colitis and also collected samples from colons of IBD patients. Samples were taken from both inflamed and uninflamed regions of the same colon; the total RNA was isolated, and the mRNA and microRNA expressions were monitored. We have determined that AXL is highly induced in active-inflamed colon, which is accompanied with reduced expression of AXL-regulating microRNAs. In addition, the expression of genes responsible for inducing or maintaining mesenchymal phenotype, such as SNAI1, ZEB2, VIM, MMP9, and HIF1α, were all significantly induced in the active-inflamed colon of IBD patients while the epithelial marker E-cadherin (CDH1) was downregulated. We also show that, in vitro, monocytic and colonic epithelial cells increase the expression of AXL in response to LPS or TNFα stimuli, respectively. In summary, we identified several interacting genes and microRNAs with mutually exclusive expression pattern in active-inflamed colon of IBD patients. Our results shed light onto a possible AXL- and microRNA-mediated regulation influencing epithelial-to-mesenchymal transition in IBD.

Various studies have established the possibility of non-bacterial methane (CH 4 ) generation in oxido-reductive stress conditions in plants and animals. Increased ethanol input is leading to oxido-reductive imbalance in eukaryotes, thus our aim was to provide evidence for the possibility of ethanol-induced methanogenesis in non-CH 4 producer humans, and to corroborate the in vivo relevance of this pathway in rodents. Healthy volunteers consumed 1.15 g/kg/day alcohol for 4 days and the amount of exhaled CH 4 was recorded by high sensitivity photoacoustic spectroscopy. Additionally, Sprague-Dawley rats were allocated into control, 1.15 g/kg/day and 2.7 g/kg/day ethanol-consuming groups to detect the whole-body CH 4 emissions and mitochondrial functions in liver and hippocampus samples with high-resolution respirometry. Mitochondria-targeted L-alpha-glycerylphosphorylcholine (GPC) can increase tolerance to liver injury, thus the effects of GPC supplementations were tested in further ethanol-fed groups. Alcohol consumption was accompanied by significant CH 4 emissions in both human and rat series of experiments. 2.7 g/kg/day ethanol feeding reduced the oxidative phosphorylation capacity of rat liver mitochondria, while GPC significantly decreased the alcohol-induced CH 4 formation and hepatic mitochondrial dysfunction as well. These data demonstrate a potential for ethanol to influence human methanogenesis, and suggest a biomarker role for exhaled CH 4 in association with mitochondrial dysfunction.

BACKGROUND:Methanogenesis can indicate the fermentation activity of the gastrointestinal anaerobic flora. Methane also has a demonstrated anti-inflammatory potential. We hypothesized that enriched methane inhalation can influence the respiratory activity of the liver mitochondria after an ischemia-reperfusion (IR) challenge.METHODS:The activity of oxidative phosphorylation system complexes was determined after in vitro methane treatment of intact liver mitochondria. Anesthetized Sprague-Dawley rats subjected to standardized 60-min warm hepatic ischemia inhaled normoxic air (n = 6) or normoxic air containing 2.2% methane, from 50 min of ischemia and throughout the 60-min reperfusion period (n = 6). Measurement data were compared with those on sham-operated animals (n = 6 each). Liver biopsy samples were subjected to high-resolution respirometry; whole-blood superoxide and hydrogen peroxide production was measured; hepatocyte apoptosis was detected with TUNEL staining and in vivo fluorescence laser scanning microscopy.RESULTS:Significantly decreased complex II-linked basal respiration was found in the normoxic IR group at 55 min of ischemia and a lower respiratory capacity (~60%) and after 5 min of reperfusion. Methane inhalation preserved the maximal respiratory capacity at 55 min of ischemia and significantly improved the basal respiration during the first 30 min of reperfusion. The IR-induced cytochrome c activity, reactive oxygen species (ROS) production and hepatocyte apoptosis were also significantly reduced.CONCLUSIONS:The normoxic IR injury was accompanied by significant functional damage of the inner mitochondrial membrane, increased cytochrome c activity, enhanced ROS production and apoptosis. An elevated methane intake confers significant protection against mitochondrial dysfunction and reduces the oxidative damage of the hepatocytes.

Due to their diverse physiological functions, mitochondria can cause various acute and chronic liver diseases, thus being potential targets for therapies and diagnostics as well. In this study, the advantages of high-resolution respirometry are presented for the assessment of liver mitochondrial functions. During respitometry, the mitochondrial electron transport, the oxydative phosphorilation and the efficacy of the ADP synthesis can be calculated on the basis of oxygen consumption of freshly-taken tissue samples. Respirometry is a robust tool for the pre- or intraoperative analysis of liver mitochondrial functions and may increase the effectiveness of surgical interventions.

Absztrakt A mitochondriumok kulcsfontosságú élettani feladataiknál fogva oki szerepet játszanak számos akut és krónikus májbetegség kialakulásában, így e sejtalkotók terápiás és lehetséges diagnosztikus célpontok is egyben. Jelen tanulmányunk során bemutatunk egy vizsgálómódszert, amely nagy felbontású respirométer (oxigráf) segítségével lehetővé teszi a mitochondrialis funkciók értékelését. A vizsgálatok során friss szövetminták oxigénfogyasztásának meghatározása alapján az oxidatív foszforilációt és a mitochondrialis légzési lánc működését nagy pontossággal, valós időben lehet vizsgálni. A respirometriás módszer lehetőséget adhat a műtét előtt vagy alatt vett biopsziákból a májmitochondriumok funkcionális vizsgálatára is, így hozzájárulhat a sebészeti beavatkozások hatékonyságának növeléséhez.

BackgroundWe hypothesized that L-alpha-glycerylphosphorylcholine (GPC), a deacylatedphosphatidylcholine derivative, can influence the mitochondrial respiratory activity and in this way, may exert tissue protective effects.MethodsRat liver mitochondria were examined with high-resolution respirometry to analyze the effects of GPC on the electron transport chain in normoxic and anoxic conditions. Besides, Sprague-Dawley rats were subjected to sham operation or standardized liver ischemiareperfusion (IR), with or without GPC administration. The reduced glutathione (GSH) and oxidized glutathione disulfide (GSSG), the tissue myeloperoxidase, xanthine oxidoreductase and NADPH oxidases activities were measured. Tissue malondialdehyde and nitrite/nitrate formation, together with blood superoxide and hydrogen-peroxide production were assessed.ResultsGPC increased the efficacy of complex I-linked mitochondrial oxygen consumption, with significantly lower in vitro leak respiration. Mechanistically, liver IR injury was accompanied by deteriorated mitochondrial respiration and enhanced ROS production and, as a consequence, by significantly increased inflammatory enzyme activities. GPC administration decreased the inflammatory activation in line with the reduced oxidative and nitrosative stress markers.ConclusionGPC, by preserving the mitochondrial complex I function respiration, reduced the biochemical signs of oxidative stress after an IR episode. This suggests that GPC is a mitochondriatargeted compound that indirectly suppresses the activity of major intracellular superoxidegenerating enzymes.

There are opposite views in the available literature: Whether physical exercise has a protective effect or not on the onset of inflammatory bowel disease (IBD). Therefore, we investigated the effects of recreational physical exercise before the induction of colitis. After 6 weeks of voluntary physical activity (running wheel), male Wistar rats were treated with TNBS (10 mg). 72 hrs after trinitrobenzene sulphonic acid (TNBS) challenge we measured colonic gene (TNF-α, IL-1β, CXCL1 and IL-10) and protein (TNF-α) expressions of various inflammatory mediators and enzyme activities of heme oxygenase (HO), nitric oxide synthase (NOS), and myeloperoxidase (MPO) enzymes. Wheel running significantly increased the activities of HO, constitutive NOS (cNOS) isoform. Furthermore, 6 weeks of running significantly decreased TNBS-induced inflammatory markers, including extent of lesions, severity of mucosal damage, and gene expression of IL-1β, CXCL1, and MPO activity, while IL-10 gene expression and cNOS activity were increased. iNOS activity decreased and the activity of HO enzyme increased, but not significantly, compared to the sedentary TNBS-treated group. In conclusion, recreational physical exercise can play an anti-inflammatory role by downregulating the gene expression of proinflammatory mediators, inducing anti-inflammatory mediators, and modulating the activities of HO and NOS enzymes in a rat model of colitis.

Psoriasis, a common chronic skin disease is, among others, characterized by epidermal hyperplasia and altered cytokine milieu. The most widely held model of psoriasis pathogenesis proposes that keratinocyte hyperproliferation is triggered by cutaneous lymphocyte infiltration, activation and differentiation of inflammatory cells and that these events generate a localized cytokine environment [ [1] Gudjonsson J.E. Johnston A. Sigmundsdottir H. Valdimarsson H. Immunopathogenic mechanisms in psoriasis. Clin Exp Immunol. 2004; 135: 1-8 Crossref PubMed Scopus (306) Google Scholar ]. Despite the heterogeneity of cytokine networks [ [2] Swindell W.R. Xing X. Stuart P.E. Chen C.S. Aphale A. Nair R.P. et al. Heterogeneity of inflammatory and cytokine networks in chronic plaque psoriasis. PLoS ONE. 2012; 7: e34594 Crossref PubMed Scopus (55) Google Scholar ] these effector molecules both sustain and reinforce the pathogenic cascade in psoriasis. Hence, psoriasis plaques formation involves the interaction between inflammatory and resident tissue cells, primarily mediated by various cytokines such as TNF-α, IL-6, IL-23, IL-17, CXCL8 [ [3] Lowes M.A. Bowcock A.M. Krueger J.G. Pathogenesis and therapy of psoriasis. Nature. 2007; 445: 866-873 Crossref PubMed Scopus (1368) Google Scholar ]. Recently introduced therapeutic approaches in the management of psoriasis indeed depend on neutralizing the given cytokine [ [4] Williams S.C. New biologic drugs get under the skin of psoriasis. Nat Med. 2012; 18: 638 Crossref PubMed Scopus (15) Google Scholar ] which reiterates the central role of secreted effector molecules in the pathophysiology of the disease. These data clearly shows, that even though cytokines play essential role during innate immune responses of the host, their expression must be tightly regulated since unrestrained cytokine secretion generates a chronic inflammatory milieu, leading to autoimmune diseases [ [5] Rothlin C.V. Ghosh S. Zuniga E.I. Oldstone M.B. Lemke G. TAM receptors are pleiotropic inhibitors of the innate immune response. Cell. 2007; 131: 1124-1136 Abstract Full Text Full Text PDF PubMed Scopus (722) Google Scholar ]. Since elevated cytokine levels, even in the absence of microbial superinfection, are a hallmark of psoriasis we hypothesized malfunctions in the negative regulation of innate immune response and clearance of apoptotic cells in diseased skin. TAM family of receptor tyrosine kinases – Tyro3, Axl, Mer – and their common ligand Gas6, among others, play central role in the intrinsic inhibition of the inflammatory response to pathogens and regulate phagocytosis of apoptotic cells [ 5 Rothlin C.V. Ghosh S. Zuniga E.I. Oldstone M.B. Lemke G. TAM receptors are pleiotropic inhibitors of the innate immune response. Cell. 2007; 131: 1124-1136 Abstract Full Text Full Text PDF PubMed Scopus (722) Google Scholar , 6 Lemke G. Rothlin C.V. Immunobiology of the TAM receptors. Nat Rev Immunol. 2008; 8: 327-336 Crossref PubMed Scopus (581) Google Scholar ]. Thus, we sought to determine the expression pattern of these regulators of innate immunity and phagocytosis in a mouse model of psoriasis and subsequently in uninvolved and involved skin of psoriatic patients.

s relating to the subject of the thesis Strifler G, Tuboly E, Szél E, Kaszonyi E, Cao C, Kaszaki J, Mészáros A, Boros M, Hartmann P. Inhaled Methane limits the mitochondrial electron transport chain dysfunction during experimental liver ischemia-reperfusion injury. EUROPEAN SURGICAL RESEARCH 55:(Suppl. 1) Paper OP-12. (2015) Strifler G, Fehér Á, Kaszonyi E, Gowda A, Kaszaki J, Boros M, Hartmann P. Metánlélegeztetés májmitokondriumokra gyakorolt hatása részleges máj ischaemiareperfúziós károsodásban patkányokban. MAGYAR SEBÉSZET 68:(3) p. 115. (2015) Strifler G, Hartmann P, Mészáros A, Kaszonyi E, Cao C, Kaszaki J, Boros M. Effects of methane inhalation on rat liver mitochondria following partial hepatic ischemia. ACTA PHYSIOLOGICA 211:(S697) p. 170. (2014) List of full papers not directly relating to the subject of the thesis Szalai Z, Szász A, Nagy I, Puskás LG, Kupai K, Király A, Magyariné Berkó A, Pósa A, Strifler G, Baráth Z, Nagy LI, Szabó R, Pávó I, Murlasits Z, Gyöngyösi M, Varga C. Antiinflammatory effect of recreational exercise in TNBS induced colitis in rats: role of NOS/HO/MPO system. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014: Paper 925981. 11 p. (2014) IF: 3,516 Szasz A, Strifler G, Voros A, Vaczi B, Tubak V, Puskas LG, Belso N, Kemeny L, Nagy I. The expression of TAM receptors and their ligand Gas6 is downregulated in psoriasis. JOURNAL OF DERMATOLOGICAL SCIENCE 71:(3) pp. 215-216. (2013) IF: 3,335 Cumulative IF: 12,965