Nedd4 antagonizes Notch signaling by promoting degradation of Notch and Deltex. This Nedd4 function may be important for protecting unstimulated cells from sporadic activation of Notch signaling.

Mannan-binding protein (MBP) is Mannan-binding protein (MBP),1 also called mannose-binding protein (MBP) or mannan-binding lectin, is a Ca 2ϩ -dependent (C-type) serum lectin and an important serum component associated with innate immunity (1-4). Human MBP is a homo-oligomer of an ϳ31-kDa subunit, each subunit containing a carbohydrate recognition domain followed by a short neck region on the COOH-terminal side and a collagen-like domain followed by a short cysteine-rich region on the NH 2 -terminal side. Three subunits form a structural unit, and MBP normally consists of two to six structural units joined through disulfide bonds at the amino termini, the whole molecular mass being ϳ200 -600 kDa (5, 6).The carbohydrate specificity of MBP is rather broad (it binds to mannose, N-acetylglucosamine, and fucose) in accordance with the fact that MBP binds to the cell surfaces of a wide variety of pathogens (7,8). MBP exhibits complement-dependent bactericidal activity, i.e. the Escherichia coli K12 and B strains, which have exposed N-acetylglucosamine and L-glycero-D-mannoheptose residues, respectively, are killed by MBP with the aid of complement (8). In addition, 1-deoxymannojirimycin (an ␣-mannosidase inhibitor)-treated baby hamster kidney cells, which have high mannose type oligosaccharides exposed on their surfaces, are also killed by MBP with the aid of complement (9). This complement activation pathway is called the lectin pathway (10). MBP has also been shown to function as a direct opsonin (11) and to prevent virus infection (12, 13). 1 The abbreviations used are: MBP, mannan-binding protein; AAL, A. aurantia lectin; CID, collision-induced dissociation; ConA, concanavalin A; FACS, fluorescence-activated cell sorter; FCS, fetal calf serum; FITC, fluorescein 4-isothiocyanate; Fuc, fucose; Hex, hexose; HexNAc, N-acetylhexosamine; HPLC, high performance liquid chromatography; LA, lectin affinity; LacNAc, N-acetyllactosamine; LCA, Lens culinaris lectin; Le, Lewis antigen; LTA, Lotus tetragonolobus lectin; mAb, monoclonal antibody; MALDI, matrix-assisted laser desorption/ ionization; MLO, MBP ligand oligosaccharides; MLO-A1, MBP ligand oligosaccharide-acidic fraction (monosialylated); MLO-N, MBP ligand oligosaccharide-neutral fraction; MS, mass spectrometry; MS/MS, tandem mass spectrometry; nano-ESI, nanoelectrospray ionization; PA, 2-aminopyridine; PBS, phosphate-buffered saline; PHA-E4, P. vulgaris erythroagglutinating lectin; PHA-L4, P. vulgaris leukoagglutinating lectin; PNA, peanut lectin; TOF, time-of-flight. All of the sugar residues have the D configuration except fucose, which has the L configuration.

A case of true pancreaticoduodenal artery (PDA) aneurysm is reported. A calcified lesion was initially detected by plain x-ray films, and an essential diagnosis was made before operation by intravenous digital subtraction angiography (IVDSA). Surgical resection of the aneurysm was performed successfully. Additionally, we reviewed a total of 82 cases with PDA aneurysm out of the 88 cases that had been reported in the English-language literature up to 1993. Fifty-three cases were accompanied by aneurysmal rupture (rupture group), and 29, including our case, were without rupture (nonrupture group). Because of the high mortality rate (49.1%) in the rupture group, a precise diagnosis and adequate treatment of PDA aneurysm before rupture is important. In the nonrupture group, a calcification on radiography appeared in 61.6% of the cases in which aneurysms were not found incidentally; this seems to be a significant indication for angiography. Moreover, intravenous digital subtraction angiography is quite useful for the screening of PDA aneurysm because it is an easy and noninvasive examination.

Hox genes are in principle tandemly arranged in an order colinear with their order of expression along the anterior-posterior axis. Combinations of Hox proteins encode information that specifies the unique characteristics of axial regions in the metazoan body plan. The independent regulation of Hox genes achieved by differential promoter activity is essential for the expression of Hox proteins in distinct territories and thereby creating a full repertoire of Hox codes. Here we report the abundant expression of transcriptional readthrough products of two adjacent Hox genes, Ubx, and Antp, in five crustacean species of Branchiopoda and Malacostraca. Bicistronic mRNA places Antp under the control of the Ubx promoter, which is active in the posterior segments of two branchiopodans Daphnia and Artemia, and would normally reduce the complexity of Hox codes if translated. This does not occur, however, as the translational capability of the bicistronic mRNA is limited. In Daphnia, bicistronic Ubx/Antp mRNA produced no significant level of either UBX or ANTP. In Artemia, on the other hand, the bicistronic mRNA produced only UBX, and replaced the role of monocistronic Ubx mRNA. In this way, multiple post-transcriptional control mechanisms in two extant branchiopodans can be seen as preventing the potentially deleterious consequences of Hox gene fusion.

The aim of this study was to investigate how insulin secretion is controlled by phosphorylation of the myosin light chain (MLC). Ca2+-evoked insulin release from pancreatic islets permeabilized with streptolysin O was inhibited by different monoclonal antibodies against myosin light-chain kinase (MLCK) to an extent parallel to their inhibition of purified MLCK. Anti-MLCK antibody also inhibited insulin release caused by the stable GTP analog guanosine 5′- O-(3-thiodiphosphate), even at a substimulatory concentration (0.1 μM) of Ca2+. Free Ca2+ increased MLC peptide phosphorylation by β-cell extracts in vitro. In contrast to the phosphorylation by purified MLCK or by calmodulin (CaM) kinase II, the activity partially remained with the β-cell under nonstimulatory Ca2+ (0.1 μM) conditions. The MLCK inhibitor ML-9 inhibited the activity in the β-cell with both substimulatory and stimulatory Ca2+, whereas KN-62, an inhibitor of CaM kinase II, only exerted an influence in the latter case. ML-9 decreased intracellular granule movement in MIN6 cells under basal and acetylcholine-stimulated conditions. We propose that MLC phosphorylation may modulate translocation of secretory granules, resulting in enhanced insulin secretion.

CD44, a cancer stem cell (CSC) marker, is required for maintaining CSC properties in hepatocellular carcinoma (HCC). Nuclear enriched abundant transcript 1 (NEAT1), a long noncoding RNA (lncRNA), is an oncogenic driver in HCC. In the present study, we investigated the significance of the NEAT1 gene in association with CD44 expression in liver CSCs of human HCC cell lines. The CSC properties were evaluated by spheroid culture, CSC marker expression, and sensitivity to anti-cancer drugs. The expression of both NEAT1 variant 1 (NEAT1v1) and variant 2 (NEAT1v2) as well as CD44 was significantly increased in the spheroid culture, compared with that in monolayer culture. Overexpression of Neat1v1, but not Neat1v2, enhanced the CSC properties, while knockout of the NEAT1 gene suppressed them. CD44 expression was increased by the overexpression of Neat1v1 and abrogated by NEAT1 knockout. The overexpression of NEAT1v1 restored the CSC properties and CD44 expression in NEAT1-knockout cells. NEAT1v1 expression in HCC tissues was correlated with poor prognosis and CD44 expression. These results suggest that NEAT1v1 is required for CD44 expression. To our surprise, NEAT1v1 also restored the CSC properties even in CD44-deficient cells, suggesting that NEAT1v1 maintains the properties of CSCs in a CD44-independent manner.

The glycosaminoglycan (GAG)-protein linkage regions of various proteoglycans share the common tetrasaccharide GlcA-Gal-Gal-Xyl-attached to Ser residues in the core proteins. In previous analysis we demonstrated unique modifications by epimerization, sulfation and phosphorylation of the component sugars. Here we developed a sensitive analytical method for the linkage region oligosaccharides to detect or monitor structural variations and changes. This will be useful for investigation of their biological roles, which are largely unknown, but they have been implicated in biosynthesis. A variety of linkage region-derived hexasaccharides was first prepared as reducing sugar chains from peptide chondroitin/dermatan sulfate of whale cartilage, shark cartilage, and bovine aorta by means of chondroitinase digestion in conjunction with beta-elimination in the absence of reducing reagents, but involving a mild alkali, 0.5 M LiOH, at 4 degrees C to prevent peeling reactions. The structures of these oligosaccharides were determined by the combination of HPLC, enzymatic digestion, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, and (1)H NMR spectroscopy, which revealed eleven different hexasaccharides including a novel structure, DeltaHexAalpha1-3GalNAcbeta1-4IdoAalpha1-3Gal(4-O-sulfate)beta1-3Galbeta1-4Xyl (DeltaHexA and IdoA represent unsaturated hexuronic acid and L-iduronic acid, respectively). These oligosaccharides were labeled with a fluorophore, 2-aminobenzamide, to prepare analytical probes using the recently developed procedure [Kinoshita and Sugahara (1999) Anal. Biochem. 269, 367-378]. The fluorophore-tagged hexasacharides of low picomoles were well separated by HPLC and successfully analyzed by MALDI-TOF mass spectrometry. The principle of the method should be applicable to the analysis of the linkage region oligosaccharides derived from heparin and heparan sulfate as well.

Cardiovascular changes associated with Graves' disease are generally considered to be secondary to the increased levels of thyroid hormone. We describe a case of Graves' disease in a 25-year-old man, who developed cardiomyopathy with severe heart failure. Pathological examination of the myocardial biopsies showed fibroblast infiltration and degenerative changes. After the cardiomyopathy subsided the patient developed a goitre and signs of hyperthyroidism, followed by Graves' ophthalmopathy, which was treated successfully with a combination of high-dose corticosteroids and orbital radiotherapy. These findings suggested a common pathogenesis for the cardiomyopathy and ophthalmopathy, and prompted us to investigate the expression of TSH receptor (TSH-R) in human heart. TSH-R mRNA was identified in human heart using the reverse transcriptasepolymerase chain reaction (RT-PCR) and DNA sequencing. Taken together, these data suggest that autoimmunity against the TSH-R might contribute to both the cardiomyopathy and ophthalmopathy in similar cases of Graves' disease.