Makoto Shimozawa

Hyperthermia attenuates TNF-alpha-induced up regulation of endothelial cell adhesion molecules in human arterial endothelial cells

Background and aim: The activation of NF-κB induces production of inflammatory cytokines and up regulation of endothelial cell adhesion molecules (ECAM). ECAM (e.g., E-selectin, VCAM-1 and ICAM-1) associates to the recruitment of leukocytes into tissue exposed to inflammatory situation. In this study, we investigated the effects of hyperthermia on the activation of NF-κB and the up regulation of E-selectin and VCAM-1 in human endothelial cells stimulated by TNF-α. Methods: Human arterial endothelial cells (HAEC) were pretreated with hyperthermia for 60 min at 42°C, followed by incubation at 37°C in a passively cooled incubator, before TNF-α stimulation. To assess the effects of hyperthermia on TNF-α-induced up regulation of ECAM and TNF-α-induced activation of NF-κB, we measured ECAM by ELISA, and evaluated the activation of NF-κB by Western blotting after TNF-α stimulation. The accumulation of HO-1, Hsp70 and IκBα in hyperthermia-treated HAEC was also assessed by Western blotting. To investigate the role of Hsp70, we treated HAEC with geranylgeranylacetone (GGA, Hsp70 inducer) 2 h before hyperthermia, and then measured ECAM in TNF-α-stimulated HAEC by ELISA. Results: Pretreatment of hyperthermia reduced TNF-α-induced up regulation of E-selectin and VCAM-1. In addition, accumulation of Hsp70, HO-1 and IκBα protein were up-regulated after hyperthermia. Furthermore, Western blotting analysis revealed that pretreatment of hyperthermia attenuated TNF-α-induced translocation of p65 into the nuclei of HAEC. Moreover, GGA enhanced Hsp70 accumulation induced by hyperthermia. Hyperthermia pretreatment combined with GGA induced further inhibition of TNF-α-induced up regulation of ECAM when compared with hyperthermia alone. Conclusion: Pretreatment of hyperthermia blocks TNF-α-induced NF-κB activation, resulting in the inhibition of ECAM up regulation in HAEC.

Rebamipide, a Gastroprotective Drug, Inhibits Indomethacin-Induced Apoptosis in Cultured Rat Gastric Mucosal Cells: Association with the Inhibition of Growth Arrest and DNA Damage-Induced 45α Expression

Rebamipide, a gastromucosal protective drug, suppresses indomethacin-induced gastropathy in humans and rodents. Effects of rebamipide on gene expression in indomethacin-treated gastric mucosal cells (RGM1) were investigated using high-density oligonucleotide arrays. Indomethacin induced apoptosis in RGM1 cells in a dose-dependent manner. Rebamipide pretreatment significantly reduced indomethacin-induced apoptosis. We used gene expression profiling on high-density oligonucleotide probe arrays to characterize the transcriptional response of RGM1 cells to indomethacin treatment for 6 hr. Of the 8,799 probes examined, 717 (8.1%) were induced (400 probes) or repressed (317 probes) at least 1.5-fold. Among the 158 genes that were induced by indomethacin at least 2.0-fold, four genes that were down-regulated by rebamipide at least 2.0-fold are listed: growth arrest and DNA-damage-inducible 45α (GADD45α), golgi SNAP receptor complex member 1, iodothyronine deiodinases, and transcription factor 8. Real time-PCR confirmed GADD45α expression and its inhibition by rebamipide. Inhibition of apoptosis-related genes is possibly important for the cytoprotective effect of rebamipide against indomethacin-induced gastric mucosal cell injury.

7-Ketocholesterol enhances the expression of adhesion molecules on human aortic endothelial cells by increasing the production of reactive oxygen species

Abstract The aim of the present study was to assess the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), monocytic adhesion of human aortic endothelial cells (HAECs), and the production of intracellular reactive oxygen species (ROS), when HAECs were stimulated by 7-ketocholesterol. 7-ketocholesterol enhances surface expression of ICAM-1 and VCAM-1 as determined by EIA, induces their mRNA expression by RT-PCR, and stimulates adhesiveness of HAECs to U937 monocytic cells. We confirmed up-regulation of ROS production of HAECs treated with 7-ketocholesterol. Although the surface expression of ICAM-1 and VCAM-1 on HAECs treated with 7-ketocholesterol increased in a time-dependent manner, α-tocopherol inhibited this increase of the surface expression of ICAM-1 and VCAM-1. In the monocytic adhesion assay, adhesion of U937 to HAECs treated with 7-ketocholesterol was enhanced, but monoclonal anti-ICAM-1 and VCAM-1 antibodies reduced the endothelial adhesiveness. In conclusion, this study suggests that the endothelial adhesiveness to monocytic cells that was increased by 7-ketocholesterol was associated with enhanced expression of ICAM-1 and VCAM-1 mediated by ROS production.

A Comparative Study on Endoscopic Ulcer Healing of Omeprazole Versus Rabeprazole with Respect to CYP2C19 Genotypic Differences

Omeprazole is mainly metabolized in the liver by CYP2C19, a genetically determined enzyme, while rabeprazole is mainly nonenzymatically degraded with a minor involvement by CYP2C19. We investigated the gastric ulcer healing effect of omeprazole versus rabeprazole evaluated endoscopically with reference to the different CYP2C19 genotypes. Eighty patients with active gastric ulcer were treated with a daily dose of 20 mg of omeprazole or 10 mg of rabeprazole. The endoscopic evaluation was performed at the baseline and 2- and 8-week posttreatment periods. The endoscopic improvement of gastric ulcer size and ulcer healing rates using a thin rubber disc with a diameter of 6 mm, were evaluated in relation to the CYP2C19 genotypic status. The mean 2-week posttreatment ulcer size value by rabeprazole did not significantly differ among the different CYP2C19 genotypes, whereas the mean value in the homozygous extensive metabolizer patients treated with omeprazole was significantly (P = 0.0057) greater than in those with rabeprazole. However, after the 8-week treatment, omeprazole and rabeprazole showed the similarly high healing rates of 87.8% (31/37) and 88.9% (32/36), respectively. Although both omeprazole and rabeprazole showed a high healing rate of gastric ulcer after the 8-week treatment period, the healing effect of rabeprazole appears to be relatively independent of the CYP2C19 status, resulting in an earlier repair of gastric mucosal damage evaluated endoscopically compared to that of omeprazole.

Inhibitory Effects of Red Wine Extracts on Endothelial-Dependent Adhesive Interactions with Monocytes Induced by Oxysterols

Red wine polyphenolic compounds have been demonstrated to possess antioxidant properties, and several studies have suggested that they might constitute a relevant dietary factor in the protection from coronary heart disease. The aim of the present study is to examine whether red wine extracts (RWE) can ameliorate oxysterol-induced endothelial response, and whether inhibition of adhesion molecule expression is involved in monocyte adhesion to endothelial cells. Surface expression and mRNA levels of adhesion molecules (intercellular adhesion molecule 1 and vascular cell adhesion molecule 1) were determined by ELISA and RT-PCR performed on human aortic endothelial cells (HAEC) monolayers stimulated with 7beta-hydroxycholesterol or 25-hydroxycholesterol. Incubation of HAEC with oxysterols (10 microM) increased expression of adhesion molecules in a time-dependent manner. Pretreatment of HAEC with RWE at final concentrations of 1, 10, and 100 ng/ml significantly inhibited the increase of surface protein expression and mRNA levels. Adherence of monocytes to oxysterol-stimulated HAEC was increased compared to that of unstimulated cells. Treatment of HAEC with RWE significantly inhibited adherence of monocytes. These results suggest that RWE works as an anti-atherogenic agent through the inhibition of endothelial-dependent adhesive interactions with monocytes induced by oxysterols.

The inhibitory effect of alacepril, an angiotensin-converting enzyme inhibitor, on endothelial inflammatory response induced by oxysterol and TNF-α

Abstract The objectives were to determine the effects of alacepril, an angiotensin-converting enzyme inhibitor, on the expression of adhesion molecules and monocyte adherence to endothelial cells induced by 7-ketocholesterol (7-KC) and tumor necrosis factor (TNF)-α. We used human aortic endothelial cells (HAECs) and U937 monocytic cells. Surface expression and mRNA levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) were determined by EIA and RT-PCR. Adherence of U937 to HAECs was assessed by adhesion assay. Incubation of HAEC with 7-KC increased the surface expression of protein and mRNA levels of ICAM-1 and VCAM-1 on HAECs and the production of reactive oxygen species (ROS) in HAECs. Pretreatment with alacepril reduced the enhanced expression of these molecules in a dose-dependent manner. The inhibitory effect of alacepril against 7-KC or TNF-α-induced CAMs expression was stronger than that of captopril or enalapril. Alacepril inhibited the production of ROS in HAECs stimulated by 7-KC or TNF-α. These results suggest that alacepril works as anti-atherogenic agent through inhibiting endothelial-dependent adhesive interactions with monocytes induced by 7-KC and TNF-α.

Gene expression analysis following hypoxia-reoxygenation in rat gastric epithelial cells using a high-density oligonucleotide array

Abstract Recent investigations have demonstrated that the signaling of hypoxia–re-oxygenation is a major contributing pathway leading to gastric mucosal injury induced by stress, non-steroidal anti-inflammatory drugs, and Helicobacter pylori. The aim of the present study was to perform a gene expression analysis on the gastric mucosal cellular response to hypoxia–reoxygenation using a high-density oligonucleotide array. Cells were subjected to hypoxia with 95% N2 and 5% CO2 at 37°C for 2 h. Reoxygenation was initiated by placing the cells in an environment of normoxia for 2 h. Total RNA was extracted, and differences in gene expression profiles between the normoxia and hypoxia–reoxygenation groups were investigated using a GeneChip of Rat Toxicology U34 array (Affymetrix). Hypoxia–reoxygenation up-regulated the stress-related genes (heat shock protein-70 [HSP-70], catalase). The enhanced expression of HSP-70 was confirmed by Western blot analysis. In conclusion, these results suggest that up-regulation of the HSP-70 gene after reoxygenation may play a role in maintaining cell survival and supporting cell function as a molecular chaperone.