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PDF file, 2456K, Proliferation curves of HUVEC as generated by xCELLigence RTCA seeding 2x103 cells/well during a period of 72 hours, in the presence of 8% FBS, or 40ng/ml VEGF plus or minus 10 muM ERFR, 10nM RERF or 10 muM RERF. Data are the mean+SD of one experiment, performed in quadruplicate.

The receptor for the urokinase-type plasminogen activator (uPAR) is a widely recognized master regulator of cell migration, and uPAR88–92 is the minimal sequence required to induce cell motility. We previously showed that soluble forms of uPAR elicit angiogenic responses through their uPAR88–92 chemotactic sequence and that the synthetic peptide SRSRY exerts similar effects. By a drug design approach, based on the conformational analysis of the uPAR88–92 sequence, we developed peptides (pERERY, RERY, and RERF) that potently inhibit signaling triggered by uPAR88–92. In this study, we present evidence that these peptides are endowed also with a clear-cut antiangiogenic activity, although to different extents. The most active, RERF, prevents tube formation by human endothelial cells exposed to SRSRY. RERF also inhibits VEGF-triggered endothelial cell migration and cord-like formation in a dose-dependent manner, starting in the femtomolar range. RERF prevents F-actin polymerization, recruitment of αvβ3 integrin at focal adhesions, and αvβ3/VEGFR2 complex formation in endothelial cells exposed to VEGF. At molecular level, the inhibitory effect of RERF on VEGF signaling is shown by the decreased amount of phospho-FAK and phospho-Akt in VEGF-treated cells. In vivo, RERF prevents VEGF-dependent capillary sprouts originating from the host vessels that invaded angioreactors implanted in mice and neovascularization induced by subcorneal implantation of pellets containing VEGF in rabbits. Consistently, RERF reduced the growth and vascularization rate of tumors formed by HT1080 cells injected subcutaneously in the flanks of nude mice, indicating that RERF is a promising therapeutic agent for the control of diseases fuelled by excessive angiogenesis such as cancer. Mol Cancer Ther; 12(10); 1981–93. ©2013 AACR.

Background: Endotoxemia causes endothelial dysfunction and microthrombosis, which are pathogenic mechanisms of coagulopathy and organ failure during sepsis. Simvastatin has potential anti-thrombotic effects on liver endothelial cells. We investigated the hemostatic changes induced by lipopolysaccharide (LPS) and explored the protective effects of simvastatin against liver vascular microthrombosis. Methods and results: We compared male Wistar rats exposed to LPS (5 mg/kg one i.p. dose) or saline in two experimental protocols—placebo (vehicle) and simvastatin (25 mg/kg die, orally, for 3 days before LPS). Morphological studies were performed by light- and electron-microscopy analyses to show intravascular fibrin deposition, vascular endothelial structure and liver damage. Peripheral- and organ-hemostatic profiles were analyzed using whole blood viscoelastometry by ROTEM, liver biopsy and western-blot/immunohistochemistry of thrombomodulin (TM), as well as immunohistochemistry of the von Willebrand factor (VWF). LPS-induced fibrin deposition and liver vascular microthrombosis were combined with a loss of sinusoidal endothelial TM expression and VWF-release. These changes were associated with parenchymal eosinophilia and necrosis. ROTEM analyses displayed hypo-coagulability in the peripheral blood that correlated with the degree of intrahepatic fibrin deposition (p < 0.05). Simvastatin prevented LPS-induced fibrin deposition by preserving TM expression in sinusoidal cells and completely reverted the peripheral hypo-coagulability caused by endotoxemia. These changes were associated with a significant reduction of liver cell necrosis without any effect on eosinophilia. Conclusions: Simvastatin preserves the antithrombotic properties of sinusoidal endothelial cells disrupted by LPS, deserving pharmacological properties to contrast sepsis-associated coagulopathy and hepatic failure elicited by endotoxemia

Metabolic syndrome is a cluster of several clinical conditions characterized by insulin-resistance and high cardiovascular risk. Non-alcoholic fatty liver disease is the liver expression of the metabolic syndrome, and insulin resistance can be a frequent comorbidity in several chronic liver diseases, in particular hepatitis C virus infection and/or cirrhosis. Several studies have demonstrated that insulin action is not only relevant for glucose control, but also for vascular homeostasis. Insulin regulates nitric oxide production, which mediates to a large degree the vasodilating, anti-inflammatory and antithrombotic properties of a healthy endothelium, guaranteeing organ perfusion. The effects of insulin on the liver microvasculature and the effects of IR on sinusoidal endothelial cells have been studied in animal models of non-alcoholic fatty liver disease. The hypotheses derived from these studies and the potential translation of these results into humans are critically discussed in this review.

The receptor for the urokinase-type plasminogen activator (uPAR) is a widely recognized master regulator of cell migration, and uPAR88–92 is the minimal sequence required to induce cell motility. We previously showed that soluble forms of uPAR elicit angiogenic responses through their uPAR88–92 chemotactic sequence and that the synthetic peptide SRSRY exerts similar effects. By a drug design approach, based on the conformational analysis of the uPAR88–92 sequence, we developed peptides (pERERY, RERY, and RERF) that potently inhibit signaling triggered by uPAR88–92. In this study, we present evidence that these peptides are endowed also with a clear-cut antiangiogenic activity, although to different extents. The most active, RERF, prevents tube formation by human endothelial cells exposed to SRSRY. RERF also inhibits VEGF-triggered endothelial cell migration and cord-like formation in a dose-dependent manner, starting in the femtomolar range. RERF prevents F-actin polymerization, recruitment of αvβ3 integrin at focal adhesions, and αvβ3/VEGFR2 complex formation in endothelial cells exposed to VEGF. At molecular level, the inhibitory effect of RERF on VEGF signaling is shown by the decreased amount of phospho-FAK and phospho-Akt in VEGF-treated cells. In vivo, RERF prevents VEGF-dependent capillary sprouts originating from the host vessels that invaded angioreactors implanted in mice and neovascularization induced by subcorneal implantation of pellets containing VEGF in rabbits. Consistently, RERF reduced the growth and vascularization rate of tumors formed by HT1080 cells injected subcutaneously in the flanks of nude mice, indicating that RERF is a promising therapeutic agent for the control of diseases fuelled by excessive angiogenesis such as cancer. Mol Cancer Ther; 12(10); 1981–93. ©2013 AACR.

Emerging evidence suggests that tumors contain and are driven by a cellular component that displays stem cell properties, the so-called cancer stem cells (CSCs). CSCs have been identified in several solid human cancers; however, there are no data about CSCs in primary human gastric cancer (GC). By using CD133 and CD44 cell surface markers we investigated whether primary human GCs contain a cell subset expressing stem-like properties and whether this subpopulation has tumor-initiating properties in xenograft transplantation experiments. We examined tissues from 44 patients who underwent gastrectomy for primary GC. The tumorigenicity of the cells separated by flow cytometry using CD133 and CD44 surface markers was tested by subcutaneous or intraperitoneum injection in NOD/SCID and nude mice. GCs included in the study were intestinal in 34 cases and diffuse in 10 cases. All samples contained surface marker-positive cells: CD133+ mean percentage 10.6% and CD133+/CD44+ mean percentage 27.7%, irrespective of cancer phenotype or grade of differentiation. Purified CD133+ and CD133+/CD44+ cells, obtained in sufficient number only in 12 intestinal type GC cases, failed to reproduce cancer in two mice models. However, the unseparated cells produced glandular-like structures in 70% of the mice inoculated. In conclusion, although CD133+ and CD133+/CD44+ were detectable in human primary GCs, they neither expressed stem-like properties nor exhibited tumor-initiating properties in xenograft transplantation experiments. J. Cell. Physiol. 227: 26862693, 2012. (c) 2011 Wiley Periodicals, Inc.

Aim Cancer, particularly gastric cancer (GC), is prevalently an epigenetic phenomenon that is dependent on an altered DNA methylation pattern. In gastric carcinogenesis, many genes show aberrant methylation; however, none of them may be used as a biomarker of cancer risk and progression. The authors aimed to evaluate the global DNA methylation of gastric mucosa in Helicobacter pylori (Hp)-related chronic gastritis, in GC and in 10 patients with preneoplastic lesions (ie, atrophy and intestinal metaplasia) followed up for 10 years. Methods The authors analysed 93 dyspeptic patients who underwent upper endoscopy, 41 surgical GC samples and 10 patients with preneoplastic gastric lesions followed up for 10 years after successful Hp eradication therapy. Global DNA methylation status and surrogate markers of cell proliferation and apoptosis were evaluated by immunohistochemistry using the anti5-methylcytosine (5-MC), anti-Ki-67 and anti-p53 (antiapoptotic marker)-specific antibodies, respectively. Results Global DNA methylation of gastric mucosa gradually decreased from normal mucosa to Hp-positive gastritis, Hp-positive chronic atrophic gastritis, independent of Cag-A status and GC; however, the variation was significant (p

The liver is susceptible to such oxidative and metabolic stresses as ischemia-reperfusion (I/R) and fatty acid accumulation. Probiotics are viable microorganisms that restore the gut microbiota and exert a beneficial effect on the liver by inhibiting bacterial enzymes, stimulating immunity, and protecting intestinal permeability. We evaluated Lactobacillus paracasei F19 (LP-F19), for its potential protective effect, in an experimental model of I/R (30 min ischemia and 60 min reperfusion) in rats fed a standard diet or a steatogen [methionine/choline-deficient (MCD)] diet. Both groups consisted of 7 sham-operated rats, 10 rats that underwent I/R, and 10 that underwent I/R plus 8 wk of probiotic dietary supplementation. In rats fed a standard diet, I/R induced a decrease in sinusoid perfusion ( P < 0.001), severe liver inflammation, and necrosis besides an increase of tissue levels of malondialdehyde ( P < 0.001), tumor necrosis factor-α ( P < 0.001), interleukin (IL)-1β ( P < 0.001), and IL-6 ( P < 0.001) and of serum levels of transaminase ( P < 0.001) and lipopolysaccharides ( P < 0.001) vs. sham-operated rats. I/R also induced a decrease in Bacterioides , Bifidobacterium , and Lactobacillus s pps ( P < 0.01, P < 0.001, and P < 0.001, respectively) and an increase in Enterococcus and Enterobacteriaceae ( P < 0.01 and P < 0.001, respectively) on intestinal mucosa. The severity of liver and gut microbiota alterations induced by I/R was even greater in rats with liver inflammation and steatosis, i.e., MCD-fed animals. LP-F19 supplementation significantly reduced the harmful effects of I/R on the liver and on gut microbiota in both groups of rats, although the effect was slightly less in MCD-fed animals. In conclusion, LP-F19 supplementation, by restoring gut microbiota, attenuated I/R-related liver injury, particularly in the absence of steatosis.