Glycogen synthase kinase 3 has a limited role in cell cycle regulation of cyclin D1 levels

BACKGROUND: The expression level of cyclin D1 plays a vital role in the control of proliferation. This protein is reported to be degraded following phosphorylation by glycogen synthase kinase 3 (GSK3) on Thr-286. We recently showed that phosphorylation of Thr-286 is responsible for a decline in cyclin D1 levels during S phase, an event required for efficient DNA synthesis. These studies were undertaken to test the possibility that phosphorylation by GSK3 is responsible for the S phase specific decline in cyclin D1 levels, and that this event is regulated by the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway which controls GSK3. RESULTS: We found, however, that neither PI3K, AKT, GSK3, nor proliferative signaling activity in general is responsible for the S phase decline in cyclin D1 levels. In fact, the activity of these signaling kinases does not vary through the cell cycle of proliferating cells. Moreover, we found that GSK3 activity has little influence over cyclin D1 expression levels during any cell cycle phase. Inhibition of GSK3 activity by siRNA, LiCl, or other chemical inhibitors failed to influence cyclin D1 phosphorylation on Thr-286, even though LiCl efficiently blocked phosphorylation of β-catenin, a known substrate of GSK3. Likewise, the expression of a constitutively active GSK3 mutant protein failed to influence cyclin D1 phosphorylation or total protein expression level. CONCLUSION: Because we were unable to identify any proliferative signaling molecule or pathway which is regulated through the cell cycle, or which is able to influence cyclin D1 levels, we conclude that the suppression of cyclin D1 levels during S phase is regulated by cell cycle position rather than signaling activity. We propose that this mechanism guarantees the decline in cyclin D1 levels during each S phase; and that in so doing it reduces the likelihood that simple over expression of cyclin D1 can lead to uncontrolled cell growth

Effect of anti-inflammatory supplementation with whey peptide and exercise therapy in patients with COPD

SummaryBackgroundOne of the major pathophysiologies in advanced chronic obstructive pulmonary disease (COPD) has been attributed to systemic inflammation. Meta-analysis of the 2005 Cochrane Database concluded the effect of nutritional supplementation alone on stable COPD was insufficient to promote body weight gain or exercise capacity. The aim of this study was to investigate the effectiveness of nutritional supplementation therapy using a nutritional supplement containing whey peptide with low-intensity exercise therapy in stable elderly patients with COPD.MethodIn stable elderly COPD patients with %IBW and %FEV1 of less than 110 and 80%, respectively, anti-inflammatory nutritional supplementation therapy was added to low-intensity exercise therapy. Thirty-six COPD patients were divided into those with and those without the ingestion of an anti-inflammatory nutritional supplement containing whey peptide, which exhibited an anti-inflammatory effect. These two groups were designated as the nutritional support and the control groups, respectively. The body composition, skeletal muscle strength, exercise tolerance, health-related QOL (HRQOL), and inflammatory cytokines were evaluated before and three months after nutritional support combined with exercise therapy in both the nutritional support group and the control group.ResultsIn the nutritional support group, the body weight, %IBW, FM, energy intake, %AC, Alb, PImax, PEmax, 6MWD, WBI, emotional function, and CRQ total were significantly increased, and the levels of hsCRP, IL-6, IL-8, and TNF-α were reduced significantly, while no significant change was noted in any item of physiological evaluation or any biomarker in the control group.ConclusionConcomitant use of a anti-inflammatory nutritional supplement containing whey peptide, which exhibits an anti-inflammatory effect, with exercise therapy in stable elderly COPD patients with %IBW<110% and %FEV1<80% may not only increase body weight but may also inhibit systemic inflammation and thus improve exercise tolerance and HRQOL

Expression of Intercellular Adhesion Molecule-1 in the Livers of Rats Treated with Diethylnitrosamine

It has been reported that levels of soluble intercellular adhesion molecule-1 (ICAM-1) in the blood are elevated in hepatocellular carcinoma patients. In the present study, serial observations of the localization of ICAM-1 in the liver were made by light and electron microscopy in rats with carcinogen-induced cancer. Male Fisher rats were given diethylnitrosamine (DEN) orally in their drinking water. Rats were sacrificed at 6, 8, 12, or 14 weeks after the start of DEN administration and the liver tissue was collected. ICAM-1 expression in liver was assessed using indirect immunoperoxidase staining with anti-rat ICAM-1 antibody. Although ICAM-1 expression by endothelial cells in livers of DEN-treated rats was lower than in the control group at 8 weeks, it was higher in the membrane and cytoplasm of hepatocytes. The expression of ICAM-1 in mesenchymal cells was decreased, paralleling development of cellular atypia, whereas in hepatocyte membranes and cytoplasm it was increased in these atypia. ICAM-1 was localized to the cytoplasm of cancer cells, but to the membrane of hepatocytes in the treated livers at 14 weeks. Furthermore, the levels of ICAM-1 in mesenchymal cells tended to be lower in the cancerous area than in the atypical hyperplastic nodule, and were reduced as the density of cell atypia increased, in comparison to cells in areas without cancerous nodules. We concluded that ICAM-1 may be influenced the development of cancer induced in the rat liver by a chemical carcinogen

Case Report Sequential MR Images and Radiographs of Epiphyseal Osteomyelitis in the Distal Femur of an Infant

Magnetic resonance imaging (MRI) plays an important role in the diagnosis of osteomyelitis, especially during the early phase of the disease. The findings of sequential MRIs during the course of treatment in acute osteomyelitis in children have not yet been reported in the literature. We present a case of acute epiphyseal osteomyelitis in the distal femur of an infant. We monitored imaging changes by sequential MRIs and radiographs. MRI was more useful than radiograph for early diagnosis and evaluation of therapeutic response

Controlling the Concentration of Malodorous Components in Kitchen Scraps

家庭内で発生する生ｺﾞﾐはそのままの状態で保管しておくと悪臭が発生する｡この悪臭は微生物の発生に起因するものと考えられ､微生物の増殖(腐敗)を阻害することで生ｺﾞﾐの悪臭発生の抑制が期待できる｡腐敗菌の増殖抑制手段として､温度､酸素濃度､二酸化炭素濃度､水分量などの環境制御因子が挙げられる｡今回の実験では､生ｺﾞﾐを保管する環境中の温度と酸素濃度を別々に制御して､生ｺﾞﾐの形態､外観､臭気がどのように変化するのかを調べ､生ｺﾞﾐの防臭手段にこれらが効果的なのかを検討した｡保管温度の点では､腐敗の激しい25℃に比較して､5℃と15℃ではｲｵｳ系化合物等の臭気成分濃度及び形態観察に顕著な差は見られなかったことから､15℃前後の保管温度の有効性が示唆された｡次に､酸素濃度の影響については､初期の酸素濃度を低くすることにより､生ｺﾞﾐ臭は弱くなると考えられ､特に､初期酸素濃度5%に設定したものが一番臭いが弱く効果的であることが分かった｡しかしながら､4日以上経過すると初期酸素濃度に関わらず､においの強さにはほとんど違いが見られなかった｡尚､初期酸素濃度0%の無酸素状態では10日以上経過しても外観は開始時とほとんど同一であった｡The emission of malodor by kitchen scraps is a serious problem in typical households, and thus preventing such malodor emission is crucial in achieving a healthy indoor environment. Upon disposing kitchen scraps, controlling environmental factors such as temperature, oxygen concentration, pH, osmotic pressure and the water content of food is effective in inhibiting microbial growth. This research was conducted focusing especially on the effects of temperature on the emission of malodorous compounds as food decays over time. Models of kitchen scraps were observed under three different temperatures:5℃, 15℃ and 25℃. The result showed that the model kept under 25℃ showed the highest concentration of malodorous components such as diacetyl, acetaldehyde, methyl mercaptan, ethyl mercaptan, propyl mercaptan and dimethyl disulfide. However, there was only a subtle difference between the models kept under 5℃ and 15℃. Therefore, in consideration of energy conservation, keeping kitchen scraps at 15℃ would be the most efficient means of preventing malodor emission. The second research was performed to examine how oxygen concentration affected the emission of malodorant from kitchen scraps under five different oxygen concentrations:0%, 5%, 10%, 15% and 20%. As a result, the model kept under 5% oxygen concentration had lower malodorous level;however, after about four days, there was no obvious difference among all the models

Detection of the Onset of Ischemia and Carcinogenesis by Hypoxia-Inducible Transcription Factor-Based In Vivo Bioluminescence Imaging

An animal model for the early detection of common fatal diseases such as ischemic diseases and cancer is desirable for the development of new drugs and treatment strategies. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that regulates oxygen homeostasis and plays key roles in a number of diseases, including cancer. Here, we established transgenic (Tg) mice that carry HRE/ODD-luciferase (HOL) gene, which generates bioluminescence in an HIF-1-dependent manner and was successfully used in this study to monitor HIF-1 activity in ischemic tissues. To monitor carcinogenesis in vivo, we mated HOL mice with rasH2 Tg mice, which are highly sensitive to carcinogens and are used for short-term carcinogenicity assessments. After rasH2-HOL Tg mice were treated with N-methyl-N-nitrosourea, bioluminescence was detected noninvasively as early as 9 weeks in tissues that contained papillomas and malignant lesions. These results suggest that the Tg mouse lines we established hold significant potential for monitoring the early onset of both ischemia and carcinogenesis and that these lines will be useful for screening chemicals for carcinogenic potential

Effect of Hydrogen Peroxide and High Glucose on the Glucose Metabolism of Lymphoma-derived U937 Cells

Our study aimed to clarify specific oxidative stress and glucose metabolic disorders in hemodialysis patients, by examining hydrogen peroxide (H2O2) - and high glucose-induced oxidative stress, glucose transport and the failure of glycolysis. As an in vitro blood cell model of end-stage renal disease (ESRD) in patients with diabetes, human monocytic U937 cells of malignant lymphoma origin were exposed to high glucose (28.9mM) for 6 days, with 5mM H2O2 added on the last day. The generation of intracellular reactive oxygen species (ROS), glucose levels, lactate levels, AMP-activated protein kinase (AMPK) activity and Glut4 levels were examined. Exposure of U937 cells to H2O2 resulted in a significant increase in intracellular ROS generation and glucose levels. Under high glucose conditions, treatment with H2O2 significantly promoted these actions. In H2O2-induced U937 cells, AMPK activity and Glut4 levels were significantly increased, but lactate and pyruvate levels were significantly decreased. Thus, exposure of U937 cells to H2O2 and a high glucose load promoted an increase in intracellular ROS, and exposure to H2O2 induced increased glucose transport and high intracellular glucose due to reduced glycolytic metabolism. This suggests that reduced glycolytic metabolism might be induced in states of high oxidative stress in hemodialysis patients with diabetes

Pleiotropic Effects of Linagliptin Monotherapy on Levels of Nitric Oxide, Nitric Oxide Synthase, and Superoxide Dismutase in Hemodialysis Patients with Diabetes

Linagliptin is an anti-diabetic drug and the only bile-excreted dipeptidyl peptidase-4 inhibitor. Malnutrition-inflammation-atherosclerosis syndrome is an important prognostic factor for hemodialysis patients, and we previously reported anti-inflammatory effects of linagliptin in hemodialysis patients with diabetes. Inflammation can accelerate oxidative stress, vasoconstriction, and platelet aggregation. However, few studies have investigated the pleiotropic effects of linagliptin treatment on inflammation in hemodialysis patients. In this study, we have extended our previous investigations of these effects in a longer and more thorough follow-up of hemodialysis patients with diabetes. We examined 20 hemodialysis patients with diabetes who were not receiving oral diabetes drugs or insulin therapy and who exhibited inadequate glycemic control (glycated albumin levels＞20%). Linagliptin (5mg) was administered daily, and we evaluated the patients’ superoxide dismutase, 8-hydroxydeoxyguanosine, nitric oxide, nitric oxide synthase, and asymmetric dimethylarginine levels in serum at baseline and after 1, 3, and 6 months of treatment. After 6 months of treatment, superoxide dismutase levels had significantly decreased from 8.8±0.5U/ml to 7.0±0.5U/ml. Nitric oxide synthase levels were significantly increased at 3 and 6 months (maximum, 94.2±13.2µg/ml; baseline, 31.6±5.5µg/ml). After 3 months of treatment, nitric oxide levels had significantly increased from 64.5±6.6µmol/l to 104±15.4µmol/l, and remained significantly elevated at 6 months. Asymmetric dimethylarginine and 8-hydroxydeoxyguanosine levels did not change during the 6-month treatment course, and no patients exhibited hypoglycemia or other significant adverse effects. Linagliptin treatment significantly changed various markers of inflammation relevant to the atherosclerosis in malnutrition-inflammation-atherosclerosis syndrome. Therefore, linagliptin monotherapy has pleiotropic effects on inflammation in hemodialysis patients with diabetes, and may improve their prognosis