AS1949490, an inhibitor of 5'-lipid phosphatase SHIP2, promotes protein kinase C-dependent stabilization of brain-derived neurotrophic factor mRNA in cultured cortical neurons.

Brain-derived neurotrophic factor (BDNF), an essential factor for maintaining brain functions, has been reported to be reduced in various neurological diseases, including Alzheimer's disease and major depression. Therefore, new drugs to increase the BDNF expression need to be developed. Since phosphatidylinositol (3,4,5)-trisphosphate, a membrane signaling molecule produced by phosphoinositide 3 (PI3)-kinase in the BDNF signaling, is a candidate target of SH2 domain-containing inositol 5' phosphatase 2 (SHIP2, a 5'-lipid phosphatase), the present study examined the effect of a SHIP2 inhibitor AS1949490 on Bdnf expression in cultured cortical neurons. BDNF increased its own mRNA levels, and AS1949490 enhanced this positive feedback regulation. The effects of BDNF in combination with AS1949490 on the Bdnf mRNA levels were blocked by inhibitors of mitogen-activated protein kinase kinase (U0126), PI3-kinase (LY294002), phospholipase Cγ (U73122), and protein kinase C (bisindolylmaleimide I), whereas the effect of BDNF alone was inhibited only by U0126. The mRNA stability assay using actinomycin D demonstrated that AS1949490 reduced degradation of the self-amplified Bdnf mRNA levels, and this effect was disappeared in the presence of bisindolylmaleimide I. These results suggest that BDNF promoted the Bdnf mRNA stabilization in a protein kinase C-dependent manner only in the presence of AS1949490, thereby enhancing Bdnf expression. Furthermore, behavioral analyses indicated that central administration of AS1949490 caused memory-improving and anti-depressant effects in passive avoidance test and forced swim test, respectively. Therefore, inhibition of SHIP2 appears to be valuable therapeutic strategy against neurological disorders associated with insufficient BDNF functions.

Maternal Separation as Early-Life Stress Causes Enhanced Allergic Airway Responses by Inhibiting Respiratory Tolerance in Mice.

Epidemiologic studies indicate that exposure to psychosocial stress in early childhood is a risk factor of adult-onset asthma, but the mechanisms of this relationship are poorly understood. Therefore, we examined whether early-life stress increases susceptibility to adult-onset asthma by inhibiting the development of respiratory tolerance. Neonatal BALB/c female mice were aerosolized with ovalbumin (OVA) to induce immune tolerance prior to immune sensitization with an intraperitoneal injection of OVA and the adjuvant aluminum hydroxide. Maternal separation (MS) was applied as an early-life stressor during the induction phase of immune tolerance. The mice were challenged with OVA aerosol in adulthood, and allergic airway responses were evaluated, including airway hyper-responsiveness to inhaled methacholine, inflammatory cell infiltration, bronchoalveolar lavage fluid levels of interleukin (IL)-4, IL-5, and IL-13, and serum OVA-specific IgE. We then evaluated the effects of MS on the development of regulatory T (Treg) cells in bronchial lymph nodes (BLN) and on splenocyte proliferation and cytokine expression. In mice that underwent MS and OVA tolerization, the allergic airway responses and OVA-induced proliferation and IL-4 expression of splenocytes were significantly enhanced. Furthermore, exposure to MS was associated with a lower number of Treg cells in the BLN. These findings suggest that exposure to early-life stress prevents the acquisition of respiratory tolerance to inhaled antigen due to insufficient Treg cell development, resulting in Th2-biased sensitization and asthma onset. We provide the evidence for inhibitory effects of early-life stress on immune tolerance. The present findings may help to clarify the pathogenesis of adult-onset asthma.

Different impacts of acylated and non-acylated long-acting insulin analogs on neural functions in vitro and in vivo.

AIMS: Centrally administered insulin improves cognitive functions in patients with Alzheimer's disease; however, it remains unknown whether long-acting insulin analogs exert more pronounced effects than insulin. In the present study, we directly compared the effects of insulin and its analogs on neural functions in vitro and in vivo. METHODS: Cultured rat cerebral cortical neurons were treated with insulin, insulin glargine U100 (Gla), insulin detemir (Det), or insulin degludec (Deg). Moreover, these drugs were intracerebroventricularly administered to mice. Their efficacies were evaluated by biochemical and behavioral analyses. RESULTS: In cultured neurons, insulin, Gla, and Det increased phosphorylation of Akt and enhanced gene expression of brain-derived neurotrophic factor to a similar extent, although Deg was less effective. The effects of Det and Deg, but not insulin and Gla were suppressed by addition of albumin. When the drug was centrally administered, the increasing effects of insulin on the Akt phosphorylation were comparable to those of Gla but greater than those of Det in hippocampus and cerebral cortex of diabetic db/db and non-diabetic db/m+ mice. Moreover, insulin and Gla enhanced memory functions in Y-maze test and suppressed depression-like behavior in forced swim test in normal mice to a similar extent, and these effects were more potent than those of Det. CONCLUSIONS: Insulin and Gla have greater impacts on central nervous system than insulin analogs with high albumin sensitivity, such as Det and Deg. These pharmacological profiles should be taken into account for developing an insulin-based therapy to treat Alzheimer's disease.

Terpinolene, a component of herbal sage, downregulates AKT1 expression in K562 cells.

Protein kinase AKT mediates cell proliferation and survival signals, and also contributes to cancer progression. Increased expression and/or activation of AKT is involved in a variety of human cancers. In cells treated with sage or rosemary extract, mRNA and protein expression levels of AKT1 were reduced compared with those of the control cells 48 h after the herbal treatments. We found that terpinolene, a common component of sage and rosemary, markedly reduced the protein expression of AKT1 in K562 cells and inhibited cell proliferation.

PI3K/AKT/PTEN Signaling as a Molecular Target in Leukemia Angiogenesis.

PI3K/AKT/PTEN pathway is important in the regulation of angiogenesis mediated by vascular endothelial growth factor in many tumors including leukemia. The signaling pathway is activated in leukemia patients as well as leukemia cell lines together with a decrease in the expression of PTEN gene. The mechanism by which the signaling pathway regulates angiogenesis remains to be further elucidated. However, it has become an attractive target for drug therapy against leukemia, because angiogenesis is a key process in malignant cell growth. In this paper, we will focus on the roles and mechanisms of PI3K/AKT/PTEN pathway in regulating angiogenesis.

Against Lung Cancer Cells: To Be, or Not to Be, That Is the Problem.

Tobacco smoke and radioactive radon gas impose a high risk for lung cancer. The radon-derived ionizing radiation and some components of cigarette smoke induce oxidative stress by generating reactive oxygen species (ROS). Respiratory lung cells are subject to the ROS that causes DNA breaks, which subsequently bring about DNA mutagenesis and are intimately linked with carcinogenesis. The damaged cells by oxidative stress are often destroyed through the active apoptotic pathway. However, the ROS also perform critical signaling functions in stress responses, cell survival, and cell proliferation. Some molecules enhance radiation-induced tumor cell killing via the reduction in DNA repair levels. Hence the DNA repair levels may be a novel therapeutic modality in overcoming drug resistance in lung cancer. Either survival or apoptosis, which is determined by the balance between DNA damage and DNA repair levels, may lender the major problems in cancer therapy. The purpose of this paper is to take a closer look at risk factor and at therapy modulation factor in lung cancer relevant to the ROS.

Clobetasol down-regulates SLPI expression in U937 monocytoid cells.

In order to investigate how glucocorticoids affect the expression of secretory leukocyte peptidase inhibitor (SLPI), which is overexpressed in a variety of cancers, clobetasol was added to cell culture medium of U937 cells and the SLPI mRNA levels were examined. The in vitro effect of the treatment on SLPI expression was detected by reverse transcriptase-polymerase chain reaction. Clobetasol treatment of U937 cells induced an up- and down-regulation of SLPI expression in a dose-dependent manner. Western blotting confirmed the down-regulation of SLPI protein expression. We hypothesized a loop formation in the SLPI genome domain, in which the glucocorticoid receptor regulates bi-directional transcriptional activity.

Genistein downregulates presenilin 1 and ubiquilin 1 expression.

The aim of this study was to determine the effects of several food ingredients and chemical inhibitors on the expression of presenilin, a molecule involved in γ-secretase activity and the generation of amyloid-ß peptide in Alzheimer's disease. Western blotting revealed the downregulation of presenilin 1 protein expression by stimulation with genistein in vitro, while the effects on presenilin 1 gene expression examined by reverse transcriptase-polymerase chain reaction (RT-PCR) were unaltered in Daudi cells. Genistein likely downregulates presenilin via the inhibition of ubiquilin 1 expression in lymphoid cells. Our findings provide new insights that may help to establish preventive strategies against Alzheimer's disease.

Clobetasol synergistically diminishes Ciz1 expression with genistein in U937 cells.

Cip-interacting zinc finger protein 1 (Ciz1) stimulates DNA replication and has been implicated in the tumorigenesis of breast cancer cells. In order to investigate the possibility of using medicinal glucocorticoids against breast cancer, we studied whether certain glucocorticoids affect the expression of Ciz1. The in vitro effect of clobetasol treatment on the reduction of Ciz1 expression was detected by reverse transcriptase-polymerase chain reaction. Western blotting also confirmed the down-regulation of the protein in a dose-dependent manner upon clobetasol treatment in U937 monocytoid cells. Furthermore, we found that Ciz1 protein expression was decreased after pre-treatment of the cells with clobetasol and genistein. An extract of Lens culinaris also had a synergistic effect on the repression of Ciz1 protein expression.

Alternative splicings on p53, BRCA1 and PTEN genes involved in breast cancer.

Alternative splicing is a major contributor to transcriptome and proteome diversity, which can lead to the deregulation of crucial cellular processes and have been associated with a variety of human diseases including cancer. As p53, BRCA1, and PTEN proteins have a key role in preventing breast cancer formation, cancer-associated splicing variants of these tumor suppressor genes are potential molecular markers and may contribute to the development of diagnostic and prognostic methods. In the present review, we summarize these tumor suppressor genes at a viewpoint of alternative splicing involved in breast cancer.

Long-term cultivation of in vitro Apis mellifera cells by gene transfer of human c-myc proto-oncogene.

Establishment of cell lines representative of honeybee character would greatly assist in their analysis. Here, we show that immortalized cell line, designated as MYN9, has been generated from honeybee embryo by the gene transfer of human c-myc proto-oncogene. The morphology of the cell is characteristic of embryonic stem cell, although the cell is stable and does not spontaneously differentiate. Polymerase chain reaction analyses show that the cell is originated from authentic honeybee cell. It is proposed that the integration of human c-myc gene into honeybee precursor populations results in the establishment of stable cell line suitable for cellular and molecular studies.

How do you RUN on?

RUN domain is present in several proteins related to the functions of Rap and Rab family GTPases. Accumulating evidence supports the hypothesis that RUN domain-containing proteins act as a component of vesicle traffic and might be responsible for an interaction with a filamentous network linked to actin cytoskeleton or microtubules. That is to say, on one hand, RUN domains associate with Rab or Rap family proteins, on the other hand, they also might interact with motor proteins such as kinesin or myosin via intervention molecules. In this review, we summarize the background and current status of RUN domain research with an emphasis on the interaction between RUN domain and motor proteins with respect to the vesicle traffic on filamentous network.

Ethanol extracts of black pepper or turmeric down-regulated SIRT1 protein expression in Daudi culture cells.

SIRT1 is a mammalian candidate molecule involved in longevity and diverse metabolic processes. The present study aimed to determine the effects of certain herbs and spices on SIRT1 expression. Human cell lines Daudi, Jurkat, U937 and K562 were cultured in RPMI-1640. Herb and spice powders were prepared and the supernatants were collected. RT-PCR was used to quantify the expression level of the gene. Protein samples were then analyzed by Western blotting. Western blotting revealed the down-regulation of SIRT1 protein expression in Daudi cells treated with extracts of black pepper or turmeric. On the other hand, the effect on the SIRT1 gene expression examined by reverse transcription polymerase chain reaction was unaltered. In conclusion, component(s) of certain herbs and spices may induce the down-regulation of SIRT1 protein.

Turmeric and curcumin suppress presenilin 1 protein expression in Jurkat cells.

In the present study, we aimed to determine the effects of herbs or spices on the expression of presenilin 1, a molecule involved in γ-secretase activity and the generation of amyloid-ß peptide in Alzheimer's disease. Western blot analysis revealed that presenilin 1 protein expression was down-regulated by stimulation with turmeric or cinnamon extracts in vitro, while the effects on presenilin 1 gene expression examined by reverse transcriptase-polymerase chain reaction were unaltered. Our results showed that curcumin, a component of turmeric, induced the down-regulation of presenilin 1 protein in Jurkat and K562 cell lines.

Dicer functions in aquatic species.

Dicer is an RNase III enzyme with two catalytic subunits, which catalyzes the cleavage of double-stranded RNA to small interfering RNAs and micro-RNAs, which are mainly involved in invasive nucleic acid defense and endogenous genes regulation. Dicer is abundantly expressed in embryos, indicating the importance of the protein in early embryonic development. In addition, Dicer is thought to be involved in defense mechanism against foreign nucleic acids such as viruses. This paper will mainly focus on the recent progress of Dicer-related research and discuss potential RNA interference pathways in aquatic species.

Natural saline-flush is sufficient to maintain patency of immobilized-urokinase double-lumen catheter used to provide temporary blood access for hemodialysis.

BACKGROUND: Thrombotic occlusion is a frequent complication of central venous catheters used to provide temporary blood access on hemodialysis therapy. Heparin-lock is conventionally used to maintain patency of the catheter, but the necessity of heparin-lock has not been determined yet. METHODS: After the immobilized-urokinase double-lumen central venous catheter was inserted into 48 Japanese hemodialysis patients, 22 patients randomized to the heparin group received a 20-ml saline-flush, followed by 2 ml of 1,000 U/ml heparin-lock, and 26 patients randomized to the saline group received only the 20-ml saline-flush once a day for each lumen. RESULTS: Thrombotic occlusion was observed in only 1 out of 22 patients in the heparin group and 1 out of 26 patients in the saline group. No significant difference of the catheter survival was observed between the two groups (p = 0.8599). CONCLUSIONS: Natural saline-flush is sufficient for maintaining the patency of an immobilized-urokinase double-lumen central venous catheter.