Redox regulation of tumor suppressor PTEN in cell signaling.

Phosphatase and tensin homologs deleted on chromosome 10 (PTEN) is a potent tumor suppressor and often dysregulated in cancers. Cellular PTEN activity is restrained by the oxidation of active-site cysteine by reactive oxygen species (ROS). Recovery of its enzymatic activity predominantly depends on the availability of cellular thioredoxin (Trx) and peroxiredoxins (Prx), both are important players in cell signaling.

Native low density lipoprotein increases the production of both nitric oxide and reactive oxygen species in the human umbilical vein endothelial cells.

Background: Nitric oxide synthases (NOSs) are a unique family of enzymes that catalyze the production of nitric oxide (NO) from L-arginine. Atherogenic action of oxidized low-density lipoproteins (oxLDL) may be mediated partly by the formation of NO in endothelial cells.

Objective: The objective of this study was to identify sources of reactive oxygen species (ROS) causing native LDL (nLDL)-induced senescence of cultured human umbilical vein endothelial cells (HUVECs).

Role of Recepteur D'origine Nantais on Gastric Cancer Development and Progression.

Recepteur d'origine nantais (RON) is a receptor tyrosine kinase belonging to the subfamily of which c-MET is the prototype. Large epidemiologic studies have confirmed the strong association between RON and gastric cancer development. Constitutive activation of RON signaling directly correlates with tumorigenic phenotypes of gastric cancer and a poor survival rate in advanced gastric cancer patients.

Redox regulation of the tumor suppressor PTEN by the thioredoxin system and cumene hydroperoxide.

Intracellular redox status influences the oxidation and enzyme activity of the tumor suppressor phosphatase and tensin homolog on chromosome 10 (PTEN). Cumene hydroperoxide (CuHP), an organic hydroperoxide, is a known tumor promoter. However, molecular targets and action mechanism of CuHP in tumor promotion have not been well characterized.

Long-Term Treatment of Native LDL Induces Senescence of Cultured Human Endothelial Cells.

The study aimed to evaluate whether the treatment of primary cultured human endothelial cells with native low-density lipoprotein (nLDL) could induce their senescence and to uncover some of the putative mechanisms involved. For this purpose, human umbilical vein endothelial cells (HUVECs) were subcultured and/or continuously cultured with nLDL (0, 2, 5, and 10 g protein/mL), for up to 9 days. The results indicated that nLDL inhibited the proliferation of HUVECs by arresting the cell cycle at G1 phase.

Assay of the redox state of the tumor suppressor PTEN by mobility shift.

PTEN is reversibly oxidized in various cells by exogenous hydrogen peroxide as well as by endogenous hydrogen peroxide generated when cells are stimulated with growth factors, cytokines and hormones. A gel mobility shift assay showed that oxidized PTEN migrated more rapidly than reduced PTEN on a non-reducing SDS-PAGE gel. Oxidized PTEN was reduced when treated with dithiothreitol.

Redox regulation of the tumor suppressor PTEN by glutathione.

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expressed in Saccharomyces cerevisiae was reversibly oxidized by hydrogen peroxide and reduced by cellular reductants. Reduction of hPTEN was delayed in each of S. cerevisiae gsh1Delta and gsh2Delta mutants.

Alterations in the activity and expression of endothelial NO synthase in aged human endothelial cells.

This study was to investigate factors underlying the age-related decrease in NO production in vascular endothelial cells. The age-related changes in NO production, the activity and expression level of eNOS, and eNOS binding proteins, were studied in HUVECs. NO production in HUVECs significantly decreased in an age-dependent manner.

Therapeutic effect of intracameral amphotericin B injection in the treatment of fungal keratitis.

Purpose: To study the therapeutic efficacy of intracameral amphotericin B (ICAMB) injection in the treatment of fungal keratitis.

Methods: Fourteen patients with fungal keratitis received ICAMB, 10 microg/0.1 mL (group A), and 17 patients received conventional treatment only (group B).

Interleukin-6 and tumor necrosis factor-alpha levels in tears of patients with dry eye syndrome.

Purpose: To determine the levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in tears of patients with dry eye syndrome.

Methods: IL-6 and TNF-alpha levels were measured by enzyme-linked immunosorbent assay in tear samples obtained from 18 patients with dry eye (8 patients with Sjögren syndrome and 10 patients with non-Sjögren syndrome) and 14 control subjects. The correlation between IL-6 and TNF-alpha levels and tear film and ocular surface parameters was analyzed.

Total peroxyl radical-trapping ability and anti-oxidant vitamins of the umbilical venous plasma and the placenta in pre-eclampsia.

Aim: Our purpose was to investigate lipid peroxide levels, total peroxyl radical-trapping anti-oxidative parameter (TRAP) values, and anti-oxidant vitamin levels in umbilical venous plasma and placental tissues, and to evaluate their roles in the pathophysiology of pre-eclampsia.

Methods: Samples of umbilical venous plasma and placental tissue homogenates were obtained from 23 normal and 18 pre-eclamptic women at between 33 and 40 weeks' gestation. The enzyme-linked immunosorbent assay method was used to assay alpha-tumor necrosis factor (TNF-alpha), and lipid peroxide levels were measured by thiobarbituric acid reaction.

Antioxidant responsiveness in BALB/c mice exposed to ozone.

Background: A single, acute exposure to ozone has been shown to modify the antioxidant defense mechanism in the respiratory tract.

Objective: The aim of this study was to evaluate the effects of ozone exposure on antioxidant response in BALB/c mice.

Methods: We measured enhanced pause of breathing (Penh) as a marker of airway obstruction using barometric whole-body plethysmography before and after ozone exposure [groups (n = 6): filtered air, 0.

A novel murine long-chain acyl-CoA synthetase expressed in brain participates in neuronal cell proliferation.

Refsum disease (RfD) is an autosomal recessive neurologic disorder of the lipid metabolism. We have identified a novel murine long-chain acyl-CoA synthetase (mLACS) associated with the RfD gene using yeast two-hybrid assay. Northern blot analyses revealed that mLACS was expressed mainly in the brain and testis.

Effect of drinking green tea on age-associated accumulation of Maillard-type fluorescence and carbonyl groups in rat aortic and skin collagen.

Tea catechins and other flavonoids have been shown to potentially protect against chronic cardiovascular diseases such as coronary heart disease and atherosclerosis. In this study, 6-month-old female Sprague-Dawley rats were fed green tea extract (50 mg/100 ml in drinking water) up to the age of 22 months, and the age-associated changes in Maillard-type fluorescence and carbonyl groups in the aortic and skin collagen were compared with those occurring in the water-fed control animals. Collagen-linked Maillard-type fluorescence was found to increase in both the aortic and skin tissues as animals aged.