Microphthalmia-associated transcription factor interacts with LEF-1, a mediator of Wnt signaling

Wnt signals regulate differentiation of neural crest cells through the β-catenin associated with a nuclear mediator of the lymphoid-enhancing factor 1 (LEF-1)/T-cell factors (TCFs) family. Here we show the interaction between the basic helix–loop–helix and leucine-zipper region of microphthalmia-associated transcription factor (MITF) and LEF-1. MITF is essential for melanocyte differentiation and its heterozygous mutations cause auditory–pigmentary syndromes. Functional cooperation of MITF with LEF-1 results in synergistic transactivation of the dopachrome tautomerase (DCT) gene promoter, an early melanoblast marker. This activation depends on the separate cis-acting elements, which are also responsible for the induction of the DCT promoter by lithium chloride that mimics Wnt signaling. β-catenin is required for efficient transactivation, but dispensable for the interaction between MITF and LEF-1. The interaction with MITF is unique to LEF-1 and not detectable with TCF-1. LEF-1 also cooperates with the MITF-related proteins, such as TFE3, to transactivate the DCT promoter. This study therefore suggests that the MITF/TFE3 family is a new class of nuclear modulators for LEF-1, which may ensure efficient propagation of Wnt signals in many types of cells

Therapeutic Effect of SHI-219, A Novel Water Soluble Prodrug of EG626 (Phtalazinol), on Mouse Dextran Sodium Sulfate -Induced Colitis

Cytokines such as IL-1β, tumor necrosis factor (TNF)-α, IL-6 and IL-8 are increased, and leukotriene (LT)B4, thromboxane (TX)B2 and PGE2 participate in inflamed colonic mucosa after administration of mouse dextran sodium sulfate (DSS). EG626 (Phthalazinol), has been shown to inhibit cyclic AMP phosphodiesterase in arteries and platelets, has an effect of anti-inflammation. The effect of SHI-219, a novel water soluble prodrug of EG626, was examined in mouse DSS-induced colitis using drinking water containing 5% DSS. When SHI-219 was given everyday, the disease activity index (DAI) representing clinical symptoms improved and the histological score decreased; furthermore, IL-1β, IL-6, and TNF-α concentrations in rectal mucosa were lower compared with the Control group. Also TXB2 and LTB4 concentrations in rectal mucosa were lower, but PGE2 concentrations in rectal mucosa were not inhibited. And then Cyclooxygenase (COX)-2 expression also correlated with the degree of inflammation in the intestinal mucosa in the SHI-219 -treated group, indicating that SHI-219 did not inhibit COX-2 expression by immunohistochemical staining. These results suggest that administration of SHI-219 may be effective in ulcerative colitis

Development of a new contrast endoscopic method With Techno Color blue P

Natural gardenia pigment has been known from old times as a dye and colorant and is presently used widely in that area as a food colorant and its safety has already been established. We have comparatively investigated the application of Techno Color blue P, which is the natural gardenia pigment, against normal pigments in contrast endoscopy. Techno Color blue P coagulated thereby decreasing its solubility as the pH of the solvent became acidic. For the upper gastrointestinal tract, 10% and the lower gastrointestinal tract 20% of the Techno Color blue P solution is appropriate. In upper gastrointestinal endoscopy, Techno Color blue P coagulates in the acid secreting areas, and is therefore unsuitable as a contrast method. However, in the pyloric gland, atrophied areas of the gastric mucosa, and duodenal villi, it was superior to Indigocarmine as a contrast method. In colonoscopy, intestinal fluids is alkaline and so Techno Color blue P showed a stable dyeing property with clearer contrasting compared to Indigocarmine. Contrast endoscopy with Techno Color blue P, is useful as a contrast method for accentuated surface morphology of the gastric mucosa, duodenal mucosa, and colonic mucosa

Effect of Copper Addition on Precipitation Behavior near Grain Boundary in Al–Zn–Mg Alloy

The effect of Cu-addition on age-hardening and precipitation have been investigated by hardness measurement, tensile test, high resolution transmission electron microscopy (HRTEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) techniques. Higher hardness, strength, and lower elongation were caused by increasing amount of Zn + Mg because of increased number density of precipitates. Cu addition also provided even higher peak hardness, strength, and lower elongation. The alloy containing highest Cu content had fine precipitates of GPB-II zones or the second clusters, in the precipitate free zones (PFZs) and the matrix, together with η′/η in the matrix from the early stage of aging. Two regions have been confirmed as the PFZs in the peak aged alloy containing highest Cu: (i) nearest to grain boundary (GB) about 70 nm in width (n-PFZ) and (ii) conventional PFZ about 400 nm in width which can be confirmed by conventional TEM (con-PFZ). The con-PFZ contains fine precipitates consisting of GPB-II zones or the second clusters, even for 2 minutes of aging at 473 K which were not present in the n-PFZ. The fine precipitates, GPB-II zones or the second clusters in the con-PFZ and the matrix disappeared at overaged condition

Catheter Ablation of Ectopic Atrial Tachycardia Originating from the Left Atrial Appendage using CARTOMERGE® System

A 70-year-old woman was referred because of drug resistant and daily incessant palpitation attack. She had undergone two previous unsuccessful radiofrequency catheter ablations at another hospital. The physical examination, chest X-ray, and echocardiogram were all normal. The 12-lead ECG during tachycardia showed narrow QRS, short PR tachycardia and negative polarity of the P wave in leads I and aVL (Fig. 1A). The ECG monitor showed incessant tachycardia with warming-up phenomenon. Three dimensional electroanatomical map integrated with CT imaging (CARTOMERGE®, Biosense Webster Inc.) clearly revealed the radial activation pattern originating from the basalo-postero-inferior aspect of the left atrial appendage. Radiofrequency energy application at this site eliminated tachycardia permanently

Peptidomic analysis of the venom of the solitary bee Xylocopa appendiculata circumvolans

Abstract Background Among the hymenopteran insect venoms, those from social wasps and bees – such as honeybee, hornets and paper wasps – have been well documented. Their venoms are composed of a number of peptides and proteins and used for defending their nests and themselves from predators. In contrast, the venoms of solitary wasps and bees have not been the object of further research. In case of solitary bees, only major peptide components in a few venoms have been addressed. Therefore, the aim of the present study was to explore the peptide component profile of the venom from the solitary bee Xylocopa appendiculata circumvolans by peptidomic analysis with using LC-MS. Methods A reverse-phase HPLC connected to ESI-OrbiTrap MS was used for LC-MS. On-line mass fingerprinting was made from TIC, and data-dependent tandem mass spectrometry gave MSMS spectra. A major peptide component was isolated by reverse-phase HPLC by conventional way, and its sequence was determined by Edman degradation, which was finally corroborated by solid phase synthesis. Using the synthetic specimen, biological activities (antimicrobial activity, mast cell devaluation, hemolysis, leishmanicidal activity) and pore formation in artificial lipid bilayer were evaluated. Results On-line mass fingerprinting revealed that the crude venom contained 124 components. MS/MS analysis gave 75 full sequences of the peptide components. Most of these are related to the major and novel peptide, xylopin. Its sequence, GFVALLKKLPLILKHLH-NH2, has characteristic features of linear cationic α-helical peptides; rich in hydrophobic and basic amino acids with no disulfide bond, and accordingly, it can be predicted to adopt an amphipathic α-helix secondary structure. In biological evaluation, xylopin exhibited broad-spectrum antimicrobial activity, and moderate mast cell degranulation and leishmanicidal activities, but showed virtually no hemolytic activity. Additionally, the peptide was able to incorporate pores in artificial lipid bilayers of azolectin, confirming the mechanism of the cytolytic activity by pore formation in biological membranes. Conclusions LC-ESI-MS and MS/MS analysis of the crude venom extract from a solitary bee Xylocopa appendiculata circumvolans revealed that the component profile of this venom mostly consisted of small peptides. The major peptide components, xylopin and xylopinin, were purified and characterized in a conventional manner. Their chemical and biological characteristics, belonging to linear cationic α-helical peptides, are similar to the known solitary bee venom peptides, melectin and osmin. Pore formation in artificial lipid bilayers was demonstrated for the first time with a solitary bee peptide