Az akut pancreatitis pathomechanizmusának és terápiájának a vizsgálata = Pathomechanism and therapy of acute pancreatitis

Choleszterin gazdag diétával kiváltott hyperlipidemia nem befolyásolta az enyhe, ödémás pancreatitist, de súlyosbította a nekrotizáló pancreatitist. Hyperlipidemia csökkentette az endogén gyökfogók és a cNOS szintjét, iNOS és NF-kB aktivációt idézett elő és fokozta az ONOO- képződést a pancreasban. Ezen eltérések lehetnek felelősek a nekrotizáló pancreatitis súlyosbodásáért. Akut pancreatitis esetén az enterális táplálás az állatok súlyvesztését, a mortalitást, a pancreatitis súlyosságát és a pancreas bakteriális felülfertőződését mérsékelte, a pancreas regenerációját gyorsította. Ezen hatásokért a bélbe jutó táplálék trophicus hatása és a bélnyálkahártya integritásáért felelős nitrogén oxid anyagcserében bekövetkező kedvező változások tehetők felelőssé. A biopsziás mintavétel nem teljesen megbízható a sessilis nyálkahártya léziók azonosításában. Ezért egy adott léziónál, a méretétől és a típusától függően a teljes, endoszkópos eltávolításra kell törekedni, hogy biztos diagnózist lehessen felállítani, ill. így egyben végleges terápiát is lehet nyújtani. Szteroid terápia klinikai, morfológiai és funkcionális regressziót eredményez autoimmun pancreatitisben. Az MR képalkotás a morfológiai és a funkcionális változásokat egyaránt képes detektálni a hasnyálmirigyben. Ez növeli a vizsgálómódszer diagnosztikus hatékonyságát a krónikus pancreatitis korai felismerésében. | Hyperlipidemia induced with cholesterol-enriched diet did not worsen edematous, but aggravated necrotizing pancreatitis. Hyperlipidemia leads to decreases in endogenous scavenger and cNOS activities, results in iNOS and NF-?B activation and stimulates ONOO- generation in the pancreas, which may be responsible for the aggravation of acute necrotizing pancreatitis. Enteral feeding reduces the weight loss, mortality, the severity of acute pancreatitis, and the bacterial superinfection of pancreas, fasten the regeneration of pancreas in experimental acute pancreatitis. The trophic effects of nutriments in the gut, and the favorable modification in nitric oxide metabolism are responsible for these changes. Forceps biopsy is insufficiently reliable for the identification of gastric polyps. These lesions should be fully resected by endoscopic mucosal resection for a final diagnosis and (depending on the lesion size and type) possibly definitive treatment. Steroid therapy is clinically, morphologically, and functionally effective in patients with autoimmun pancreatitis. MRCP permits visualization of the ductal changes and furnishes functional information on the pancreas; this combination may enhance its diagnostic accuracy so that MRCP can become a valuable diagnostic means in early-stage chronic pancreatitis

High ATP production fuels cancer drug resistance and metastasis : implications for mitochondrial ATP depletion therapy

Recently, we presented evidence that high mitochondrial ATP production is a new therapeutic target for cancer treatment. Using ATP as a biomarker, we isolated the “metabolically fittest” cancer cells from the total cell population. Importantly, ATP-high cancer cells were phenotypically the most aggressive, with enhanced stem-like properties, showing multi-drug resistance and an increased capacity for cell migration, invasion and spontaneous metastasis. In support of these observations, ATP-high cells demonstrated the up-regulation of both mitochondrial proteins and other protein biomarkers, specifically associated with stemness and metastasis. Therefore, we propose that the “energetically fittest” cancer cells would be better able to resist the selection pressure provided by i) a hostile micro-environment and/or ii) conventional chemotherapy, allowing them to be naturally-selected for survival, based on their high ATP content, ultimately driving tumor recurrence and distant metastasis. In accordance with this energetic hypothesis, ATP-high MDA-MB-231 breast cancer cells showed a dramatic increase in their ability to metastasize in a pre-clinical model in vivo. Conversely, metastasis was largely prevented by treatment with an FDA-approved drug (Bedaquiline), which binds to and inhibits the mitochondrial ATP-synthase, leading to ATP depletion. Clinically, these new therapeutic approaches could have important implications for preventing treatment failure and avoiding cancer cell dormancy, by employing ATP-depletion therapy, to target even the fittest cancer cells

A daganatos és stroma sejtek közötti interakciók vizsgálata a gyomorrák kialakulásában és progressziójában. Klinikai és kísérletes vizsgálatok. = The role of tumor-stroma interactions in the initiation and progression of gastric cancer. Clinical and experimental studies.

Kísérleteink azt mutatták, hogy a humán gyomor miofibroblaszt sejtek (HGM) száma a rákos szövetben nagy mértékben megnövekedett, továbbá morfológiai és szerkezeti károsodást szenvedtek a normál szöveti sejtekhez képest. Általunk sikerült először karakterizálni sejtkultúrában tartott miofibroblasztokon (HGMs) a Na+/H+ cserélő (NHE) 1-es, 2-es és 3-mas izoforma, a Na+/HCO3- kotranszporter (NBC) és az anion cserélő (AE) expresszióját és funkciónális aktivitását. Eredményeink arra utalnak, hogy az NHE1 nélkülözhetetlen szerepet játszik a miofibroblasztok IGF-II indukálta proliferációjában. Továbbá kimutattuk, hogy az NHE1 aktivitása hozzájárul az IGF-II és carbachol stimulálta migrációhoz. Ismert, hogy a natrium-calcium cserélők (NCX) fontos szerepet töltenek be a kontraktilis sejtek calcium homeosztázisában. Kísérleteinkben a miofibroblasztok 50%-a spontán calcium oszcillációs aktivitást mutatott, mely spontán oszcilláció gátolható volt NCX inhibitorokkal. Miofibroblaszt sejtekben az NCX1 és NCX2 mind mRNS mind fehérje szinten kimutatható volt, melyek az oszcillációs aktivitástól függetlenül hozzájárulnak az intracelluláris natrium és calcium homeosztázishozhoz. Továbbá az NCX inhibitorok szignifikánsan gátolták a bazális és IGF-II stimulálta migrációt illetve profliferációt. Eredményeink azt mutatták, hogy az NCX-ek potenciális terápiás targetként szolgálhatnak hiperproliferatív gyomor megbetegedésekben. | Our data showed that human gastric myofibroblasts (HGMs) originating from gastric cancer are greatly increased in number, their morphology is distorted and the architecture is damaged compared to those originating from nomal tissue. Then we characterized (for the first time) the expression and functional activities of the Na+/H+ exchanger (NHE) isoforms 1, 2 and 3, and the functional activities of the Na+/HCO3 - cotransporter (NBC) and the anion exchanger (AE) in cultured HGMs using microfluorimetry, immunocytochemistry, RT-PCR and immunoblot analysis. Our results indicate that NHE1 is necessary for IGF-II-induced proliferation of HGMs. In addition, we demonstrated that NHE1 activity contributes to both IGF-II- and carbachol stimulated migration. Sodium-calcium exchangers (NCX) are known to act crucial role in calcium homeostasis of contractile cells. We showed that 50% of the HGMs present calcium oscillations, which depend on extracellular calcium and sodium, and can be blocked by NCX inhibitors. NCX1 and NCX2 are present in mRNA and protein level in HGMs and they contribute to the intracellular calcium and sodium homeostasis as well – regardless of the oscillatory activity. NCX inhibitors significantly block the basal and IGF-II stimulated migration and proliferation rates of HGMs. In conclusion we showed that NCX plays a pivotal role in regulating the calcium homeostasis of HGMs, and may be a potential therapeutic target in hyperproliferative gastric diseases

Q50, an Iron-Chelating and Zinc-Complexing Agent, Improves Cardiac Function in Rat Models of Ischemia/Reperfusion-Induced Myocardial Injury

Background: Reperfusion of ischemic myocardium may contribute to substantial cardiac tissue damage, but the addition of iron chelators, zinc or zinc complexes has been shown to prevent heart from reperfusion injury. We investigated the possible beneficial effects of an iron-chelating and zinc-complexing agent, Q50, in rat models of ischemia/reperfusion (I/R)-induced myocardial infarction and on global reversible myocardial I/R injury after heart transplantation. Methods and Results: Rats underwent 45-min myocardial ischemia by left anterior descending coronary artery ligation followed by 24h reperfusion. Vehicle or Q50 (10mg/kg, IV) were given 5min before reperfusion. In a heart transplantation model, donor rats received vehicle or Q50 (30mg/kg, IV) 1h before the onset of ischemia. In myocardial infarcted rats, increased left ventricular end-systolic and end-diastolic volumes were significantly decreased by Q50 post treatment as compared with the sham group. Moreover, in I/R rat hearts, the decreased dP/dtmax and load-independent contractility parameters were significantly increased after Q50. However, Q50 treatment did not reduce infarct size or have any effect on increased plasma cardiac troponin-T-levels. In the rat model of heart transplantation, 1h after reperfusion, decreased left ventricular systolic pressure, dP/dtmax, dP/dtmin and myocardial ATP content were significantly increased and myocardial protein expression of superoxide dismutase-1 was upregulated after Q50 treatment. Conclusions: In 2 experimental models of I/R, administration of Q50 improved myocardial function. Its mechanisms of action implicate in part the restoration of myocardial high-energy phosphates and upregulation of antioxidant enzymes.  (Circ J 2013; 77: 1817–1826

Polyunsaturated fatty acids synergize with lipid droplet binding thalidomide analogs to induce oxidative stress in cancer cells

<p>Abstract</p> <p>Background</p> <p>Cytoplasmic lipid-droplets are common inclusions of eukaryotic cells. Lipid-droplet binding thalidomide analogs (2,6-dialkylphenyl-4/5-amino-substituted-5,6,7-trifluorophthalimides) with potent anticancer activities were synthesized.</p> <p>Results</p> <p>Cytotoxicity was detected in different cell lines including melanoma, leukemia, hepatocellular carcinoma, glioblastoma at micromolar concentrations. The synthesized analogs are non-toxic to adult animals up to 1 g/kg but are teratogenic to zebrafish embryos at micromolar concentrations with defects in the developing muscle. Treatment of tumor cells resulted in calcium release from the endoplasmic reticulum (ER), induction of reactive oxygen species (ROS), ER stress and cell death. Antioxidants could partially, while an intracellular calcium chelator almost completely diminish ROS production. Exogenous docosahexaenoic acid or eicosapentaenoic acid induced calcium release and ROS generation, and synergized with the analogs <it>in vitro</it>, while oleic acid had no such an effect. Gene expression analysis confirmed the induction of ER stress-mediated apoptosis pathway components, such as GADD153, ATF3, Luman/CREB3 and the ER-associated degradation-related HERPUD1 genes. Tumor suppressors, P53, LATS2 and ING3 were also up-regulated in various cell lines after drug treatment. Amino-phthalimides down-regulated the expression of CCL2, which is implicated in tumor metastasis and angiogenesis.</p> <p>Conclusions</p> <p>Because of the anticancer, anti-angiogenic action and the wide range of applicability of the immunomodulatory drugs, including thalidomide analogs, lipid droplet-binding members of this family could represent a new class of agents by affecting ER-membrane integrity and perturbations of ER homeostasis.</p

Lipid droplet binding thalidomide analogs activate endoplasmic reticulum stress and suppress hepatocellular carcinoma in a chemically induced transgenic mouse model

BACKGROUND: Hepatocellular carcinoma (HCC) is the most frequent and aggressive primary tumor of the liver and it has limited treatment options. RESULTS: In this study, we report the in vitro and in vivo effects of two novel amino-trifluoro-phtalimide analogs, Ac-915 and Ac-2010. Both compounds bind lipid droplets and endoplasmic reticulum membrane, and interact with several proteins with chaperone functions (HSP60, HSP70, HSP90, and protein disulfide isomerase) as determined by affinity chromatography and resonant waveguide optical biosensor technology. Both compounds inhibited protein disulfide isomerase activity and induced cell death of different HCC cells at sub or low micromolar ranges detected by classical biochemical end-point assay as well as with real-time label-free measurements. Besides cell proliferation inhibiton, analogs also inhibited cell migration even at 250 nM. Relative biodistribution of the analogs was analysed in native tissue sections of different organs after administration of drugs, and by using fluorescent confocal microscopy based on the inherent blue fluorescence of the compounds. The analogs mainly accumulated in the liver. The effects of Ac-915 and Ac-2010 were also demonstrated on the advanced stages of hepatocarcinogenesis in a transgenic mouse model of N-nitrosodiethylamine (DEN)-induced HCC. Significantly less tumor development was found in the livers of the Ac-915- or Ac-2010-treated groups compared with control mice, characterized by less liver tumor incidence, fewer tumors and smaller tumor size. CONCLUSION: These results imply that these amino-trifluoro-phthalimide analogs could serve potent clinical candidates against HCC alone or in combination with dietary polyunsaturated fatty acids

Sucrose esters increase drug penetration, but do not inhibit P-glycoprotein in Caco-2 intestinal epithelial cells

Sucrose fatty acid esters are increasingly used as excipients in pharmaceutical products, but few data are available on their toxicity profile, mode of action, and efficacy on intestinal epithelial models. Three water-soluble sucrose esters, palmitate (P-1695), myristate (M-1695), laurate (D-1216), and two reference absorption enhancers, Tween 80 and Cremophor RH40, were tested on Caco-2 cells. Caco-2 monolayers formed a good barrier as reflected by high transepithelial resistance and positive immunostaining for junctional proteins claudin-1, ZO-1, and -catenin. Sucrose esters in nontoxic concentrations significantly reduced resistance and impedance, and increased permeability for atenolol, fluorescein, vinblastine, and rhodamine 123 in Caco-2 monolayers. No visible opening of the tight junctions was induced by sucrose esters assessed by immunohistochemistry and electron microscopy, but some alterations were seen in the structure of filamentous actin microfilaments. Sucrose esters fluidized the plasma membrane and enhanced the accumulation of efflux transporter ligands rhodamine 123 and calcein AM in epithelial cells, but did not inhibit the P-glycoprotein (P- gp)-mediated calcein AM accumulation in MES-SA/Dx5 cell line. These data indicate that in addition to their dissolution-increasing properties sucrose esters can enhance drug permeability through both the transcellular and paracellular routes without inhibiting P-gp

Kinetic analysis of the toxicity of Cremophor EL and RH40 on endothelial and epithelial cells

Cremophor EL and RH40 are widely used excipients in oral and intravenous drug formulations such as Taxol infusion to improve drug dissolution and absorption. Studies indicate that Cremophors, especially EL, have toxic side effects, but few data are available on endothelial and epithelial cells, which form biological barriers and are directly exposed to these molecules. Human hCMEC/D3 brain endothelial and Caco-2 epithelial cells were treated with Cremophor EL and RH40 in the 0.1–50 mg/mL concentration range. Cell toxicity was monitored by real-time cell microelectronic sensing and verified by lactate dehydrogenase release and 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and morphological methods. Cremophors caused dose- and time-dependent damage in both cell types. In endothelial cells, 0.1 mg/mL and higher concentrations, in epithelial cells, concentrations of 5 mg/mL and above were toxic, especially at longer incubations. Cell death was also proven by double fluorescent staining of cell nuclei. Immunostaining for tight junction proteins claudin-4 and -5 showed barrier disruption in cells treated by surfactants at 24 h. In conclusion, Cremophor EL and RH40 in concentrations corresponding to clinical doses caused endothelial and epithelial toxicity. Endothelial cells were more sensitive to surfactant treatment than epithelial cells, and Cremophor EL was more toxic than RH40 in both cell types. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:1173–1181, 201