Neuronal protein NP25 interacts with F-actin

Neuronal protein NP25 is a neuron-specific protein present in highly differentiated neural cells, but its functional properties have not been well characterized. NP25 shows high amino acid sequence homology with the smooth muscle cell cytoskeleton-associated proteins, SM22, mp20, and calponin. To gain an insight into the biological functions of NP25, we first examined its subcellular localization in the human neuroblastoma cell line, SK-N-SH. NP25 diffusely distributed in the cytoplasm and fiber-like staining was also observed. It showed that NP25 co-localized with F-actin on stress fibers. A co-sedimentation assay demonstrated that NP25 bound to filamentous actin. Further investigations using fluorescence resonance energy transfer (FRET) technique revealed intracellular binding of NP25 and actin. The significance of the interaction between NP25 and F-actin is discussed.     

XIdax, an inhibitor of the canonical Wnt pathway, is required for anterior neural structure formation in Xenopus.

Wnt signaling pathways are involved during various stages in the development of many species. In Xenopus, the accumulation of beta-catenin on the dorsal side of embryo is required for induction of the organizer, while the head structure formation requires inhibition of Wnt signaling. Here, we report a role for xIdax, a negative regulator of Wnt signaling. XIdax is expressed in neural tissues at the neurula stage, and in the restricted region of the tadpole brain. Ectopic expression of xIdax inhibits the target gene expression, suggesting that xIdax can inhibit canonical Wnt signaling. To examine the function of xIdax, a morpholino oligo for xIdax (xIdaxMO) was designed. An injection into an animal pole cell caused a loss of forebrain. The anterior neural marker expression is decreased in xIdaxMO-injected embryo, suggesting that xIdax is required for anterior neural development. Moreover, a negative regulator that acts downstream of xIdax rescued this defect. We propose that Idax functions are dependent on the canonical Wnt pathway and are crucial for the anterior neural development.     

C and V proteins of Sendai virus target signaling pathways leading to IRF-3 activation for the negative regulation of interferon-beta production

We here report a molecular basis for downregulation of interferon (IFN)-beta production by V and C proteins of Sendai virus (SeV). The infection of HeLa cells with SeV poorly induced IFN-beta even if the expression of C/C' was disrupted. In contrast, when the expression of C/C'/Y1/Y2 or V/W was disrupted, SeV infection strongly induced IFN-beta production and significantly activated the interferon regulatory factor (IRF)-3 pathway. The independent expression of C or V inhibited the double-stranded (ds) RNA- or Newcastle disease virus (NDV)-induced activation of IRF-3 and NF-kappa B, as well as the IFN-beta promoter. This inhibitory effect was also observed when Y1, Y2, or a C-terminal half fragment (aa 85-204) of C was independently expressed. Phosphorylation and homodimer formation of IRF-3 were suppressed not only in cells infected with SeV capable of expressing both C/C'/Y1/Y2 (or Y1/Y2) and V/W, but also in HeLa cells constitutively expressing Y1. These results suggest that C, Y1, Y2, and V block signaling pathways leading to IRF-3 activation to downregulate IFN-beta production.     

In vitro and in vivo anti-allergic activity of soy sauce

Soy sauce (Shoyu) is a traditional fermented seasoning of Japan and available throughout the world. Polysaccharides were obtained from dialysate of Shoyu, and these Shoyu polysaccharides (SPS) were examined for anti-allergic activity in vitro and in vivo. The SPS originated from partially-degraded polysaccharides of soybeans by mold enzymatic hydrolyses, and Shoyu contained about 1% (w/v) SPS. First, the inhibitory effects of SPS on hyaluronidase, which is known to be related to inflammation and allergic responses, were as potent as those of an anti-allergic medicine, disodium cromoglycate. Second, SPS significantly inhibited the release of histamine from rat basophilic leukemia (RBL-2H3) cells, which had been induced by the antigen. Third, orally administered SPS had a significant suppressive effect on passive cutaneous anaphylaxis induced in the ears of mice. These results suggest that SPS may have anti-allergic activities, and soy sauce is a potentially promising seasoning for the treatment of allergic diseases through food.     

Adaptive Predictive Control of Arterial Blood Pressure Based on a Neural Network During Acute Hypotension

In acute hypotension, an automated drug infusion system to control mean arterial blood pressure (MAP) has not been previously studied, though many investigations have examined the use of vasodilating drugs to control MAP in postoperative hypertension. Therefore, we examined an automated control of MAP during acute hypotension using a neural network (NN) approach. A proportional-integral-derivative (PID) control, an adaptive predictive control using a NN (APC(NN)), a combined control of APC(NN) and PID (APC(NN-PID)), a fuzzy control, and a model predictive control were tested in computer simulation based on the MAP response to norepinephrine (NE) of 25 microg ml(-1). In six anesthetized rabbits, using the NE of 25 microg ml(-1), the PID control, APC(NN), and APC(NN-PID) prevented severe hypotension compared to an uncontrolled condition. Under PID control, four of the six animals showed MAP oscillation. Using NE of 50 microg ml(-1), the rabbits recovered from acute hypotension for all systems tested but showed sustained MAP oscillation during PID control. In conclusion, utilization of a NN for adaptive predictive control systems could facilitate the development of an automated drug infusion apparatus because it provides robust control even when acute or large perturbations and inter-individual differences in the sensitivity to therapeutic agents occur.     

Elevated expression of E-cadherin and α-, β-, and γ-catenins in metastatic lesions compared with primary epithelial ovarian carcinomas

E-cadherin and catenins play key roles in cell adhesion and motility. Little is known about the changes in expression of these molecules in the progression of ovarian carcinomas. In the present study, the immunohistochemical expression of E-cadherin and α-, β-, and γ-catenins was examined in 77 cases of ovarian carcinoma. In addition, the expression of these molecules was evaluated in 26 matched pairs of primary and metastatic lesions of advanced ovarian carcinomas. Of the 77 primary lesions, positive staining for E-cadherin and α-, β-, and γ-catenin was observed in 75 (97%), 63 (82%), 71 (92%) and 57 (74%) cases, respectively. Positivity for E-cadherin and α-, β-, and γ-catenin was significantly decreased in stage III and IV tumors compared with stage I and II tumors, suggesting that expression of the cadherin-catenin complex is reduced with the advancing stages of a tumor. Interestingly, expression of E-cadherin and α-, β-, and γ-catenin in the lesions of peritoneal dissemination was significantly increased compared with the primary lesions. These findings suggest that expression of the cadherin-catenin complex changes markedly and that reexpression may occur during the peritoneal dissemination of ovarian carcinoma cells.     

Role of macrophage migration inhibitory factor in otitis media with effusion in adults

Otitis media with effusion (OME) is one of the most common ear diseases. Bacterial endotoxins and several inflammatory cytokines appear to be involved in the pathogenesis of OME in children; however, little is known of the immunological aspects of the onset of OME in adults. We sought to determine the presence of macrophage migration inhibitory factor (MIF) as well as interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), RANTES (regulated upon activation, normal T-cell expressed and presumably secreted), and endotoxin in middle ear effusions (MEEs) from adult patients with OME. In addition, the levels of MIF in MEEs from adults and children were compared. MEE was obtained from 95 adults and 11 children. The levels of MIF, IL-1beta, TNF-alpha, and RANTES were determined by enzyme-linked immunosorbent assay, and the concentrations of endotoxin and total protein were determined by the Endospec assay and bicinchoninic acid assay, respectively. MIF was detected in 97.9% of the MEEs from adults, while endotoxin, IL-1beta, TNF-alpha, and RANTES were detected in 96.8, 12.6, 5.3, and 43.9%, respectively. In addition, the level of MIF was significantly higher than those of endotoxin, IL-1beta, and TNF-alpha. A positive correlation between the levels of MIF and endotoxin was observed. MIF and endotoxin were detected in 81.8 and 72.7%, respectively, of the MEEs from the children. The level of MIF was significantly higher in the children, and conversely that of endotoxin was significantly higher in the adults. These results suggest that the interaction between MIF and endotoxin may promote fluid collection in the middle ear, particularly in adults.     

The effect of peroxisome proliferator-activated receptor-gamma ligand on urological cancer cells

Peroxisome proliferator activator-receptor (PPAR)-gamma ligand induces growth arrest of cancer cells through apoptosis. In this study, we examined the effects of PPAR-gamma inhibitors on cell proliferation in renal cell carcinoma (RCC), bladder tumor (BT), and prostatic carcinoma (PC) cell lines. We investigated the inhibitory effect of PPAR-gamma ligands, troglitazone and 15-deoxy-Delta12,14-prostaglandin J2 (15dPGJ2) on RCC, BT and PC-derived cell lines using MTT assay and Hoechst staining. PPAR-gamma ligands (troglitazone and 15dPGJ2) induced the reduction of cell viability with the half-maximal concentration of growth inhibition of RCC, BT, and PC cell lines. Furthermore, counting cells at days 1, 2 and 3, clearly showed marked inhibition of cell proliferation using troglitazone and 15dPGJ2. All PPAR-gamma inhibitors stopped the growth of all RCC, BT and PC cells. Cells treated with PPAR-gamma inhibitors showed chromatin condensation, cellular shrinkage, small membrane-bound bodies (apoptotic bodies), and cytoplasmic condensation. These cellular changes were typically redundant characteristics of apoptosis. PPAR-gamma ligands may mediate potent antiproliferative effects against RCC, BT and PC cells through differentiation. Thus, PPAR-gamma may become a new target in treatment of urological tumors.     

Ultrastructure and chromogranin A immunogold labelling of ECL cell carcinoids

Poorly differentiated neuroendocrine cells can be difficult to recognise. Sensitive methods are needed to label cells that have lost their ultrastructural features and have reduced concentrations of neuroendocrine markers. In gastric neoplasms, enterochromaffin-like cells might dedifferentiate and lose their characteristic granules and secretory vesicles, making detection of such cells increasingly difficult. However, chromogranin A (CgA) immunogold labelling could provide sensitive and specific detection of gastric neuroendocrine cells. We present ultrastructural findings, CgA immunogold labelling as well as conventional immunohistochemical findings of two human enterochromaffin-like cell carcinoids. Electron-dense granules of poorly differentiated cells were less intensely labelled than granules in well-differentiated cells. Granules with atypical shape as well as punctuate granules previously found in neuroendocrine neoplasms were also CgA labelled. The CgA labelling efficacy after antigen retrieval in an alkaline solution was higher after heating in an autoclave at 135 degrees C compared to a microwave at 100 degrees C for both granules and secretory vesicles without significant deterioration of the ultrastructure. In conclusion, the use of CgA immunogold labelling could ensure a specific classification of cells with neuroendocrine granules and be a supplement to immunohistochemical examination of poorly differentiated tumours.