Detailed analysis of an amplified region at chromosome 11q13 in malignant tumors.

We have examined the amplification unit at chromosome band 11q13 in 12 primary tumors and one cancer cell line (A431) with 15 DNA markers. The amplified region and size varied from one tumor to another; the smallest amplicon was estimated to be 700 kb long and the largest was 4.5 Mb long at maximum, on the basis of a physical map. Furthermore, the DNA amplified in tumors was not always continuous, because in three cases one locus within the amplicon was not amplified. The amplified region common to all 13 cancers consisted of 500 kb of DNA which incorporated eight defined loci (BCL-1, cCI11-524, cCI11-283, cCI11-234, HBI-1, cCI11-454, HSTF1, and INT2). As two of them, cCI11-524 and cCI11-454, were found to contain DNA sequences conserved in other species, one or both of these loci might encode the gene(s) that may be associated with progression of these tumors.     

Upregulation of uncoupling proteins by oral administration of capsiate, a nonpungent capsaicin analog.

Capsiate is a nonpungent capsaicin analog, a recently identified principle of the nonpungent red pepper cultivar CH-19 Sweet. In the present study, we report that 2-wk treatment of capsiate increased metabolic rate and promoted fat oxidation at rest, suggesting that capsiate may prevent obesity. To explain these effects, at least in part, we examined uncoupling proteins (UCPs) and thyroid hormones. UCPs and thyroid hormones play important roles in energy expenditure, the maintenance of body weight, and thermoregulation. Two-week treatment of capsiate increased the levels of UCP1 protein and mRNA in brown adipose tissue and UCP2 mRNA in white adipose tissue. This dose of capsiate did not change serum triiodothyronine or thyroxine levels. A single dose of capsiate temporarily raised both UCP1 mRNA in brown adipose tissue and UCP3 mRNA in skeletal muscle. These results suggest that UCP1 and UCP2 may contribute to the promotion of energy metabolism by capsiate, but that thyroid hormones do not.     

cDNA cloning and characterization of an osmotically sensitive TRP channel from ascidian eggs

The transient receptor potential (TRP) ion channels are thought to be involved in the entry of calcium ion into cells. In this study, we isolated a cDNA clone, HrTRPV, that shows high homology to Caenorhabditis elegans OSM-9, a TRPV subfamily member of the TRP family, from a Halocynthia roretzi fertilized egg cDNA library. We analyzed its properties using HrTRPV-transfected cells. Upon reduction of extracellular osmolarity, the intracellular calcium concentration was found to increase in HrTRPV-transfected cells. This increase in intracellular calcium concentration was dependent on the presence of extracellular calcium ion and was inhibited by treatment with gadolinium ion, a stretch-activated calcium channel blocker. Thus, these results indicate that ascidian egg HrTRPV is an osmotically sensitive TRP channel.     

Malignant hyperthermia mutation sites in the Leu2442-Pro2477 (DP4) region of RyR1 (ryanodine receptor 1) are clustered in a structurally and functionally definable area

To explain the mechanism of pathogenesis of channel disorder in MH (malignant hyperthermia), we have proposed a model in which tight interactions between the N-terminal and central domains of RyR1 (ryanodine receptor 1) stabilize the closed state of the channel, but mutation in these domains weakens the interdomain interaction and destabilizes the channel. DP4 (domain peptide 4), a peptide corresponding to residues Leu2442-Pro2477 of the central domain, also weakens the domain interaction and produces MH-like channel destabilization, whereas an MH mutation (R2458C) in DP4 abolishes these effects. Thus DP4 and its mutants serve as excellent tools for structure-function studies. Other MH mutations have been reported in the literature involving three other amino acid residues in the DP4 region (Arg2452, Ile2453 and Arg2454). In the present paper we investigated the activity of several mutants of DP4 at these three residues. The ability to activate ryanodine binding or to effect Ca2+ release was severely diminished for each of the MH mutants. Other substitutions were less effective. Structural studies, using NMR analysis, revealed that the peptide has two a-helical regions. It is apparent that the MH mutations are clustered at the C-terminal end of the first helix. The data in the present paper indicates that mutation of residues in this region disrupts the interdomain interactions that stabilize the closed state of the channel.     

Persistence of extended-spectrum β-lactamase plasmids among Enterobacteriaceae in commercial broiler farms

To clarify the persistence of extended-spectrum β-lactamase (ESBL) producers, 13 plasmids from two broiler farms were analyzed. On the farm not using antimicrobials, one plasmid from Klebsiella pneumoniae isolated from a day-old chick was similar to that from Escherichia coli isolated a year later, with the deletion of two transposons. On the farm using antimicrobials, most circulating plasmids (eight out of nine) in a flock of 40-days-old chicks were identical, although one from K. pneumoniae had a deletion of a transposon carrying a class 1 integron containing aadA2 and dfrA12. Thus, ESBL plasmids persisted in the farms with or without antimicrobial agent use.     

Photoprotective responses of an ice algal community in Saroma-Ko Lagoon, Hokkaido, Japan

In polar seas, ice algal communities can acclimate to extremely low light conditions. Reduced acclimation to shade in ice algal communities, as a result of shortened ice seasons at the lower latitude limits of sea ice distribution, has been suggested as advantageous for avoiding strong photoinhibition when cells are released into high light levels at the water’s surface. Thermal dissipation of excess energy by xanthophyll cycle pigments in the de-epoxidated state may occur in ice algal communities released from retreating sea ice. A light exposure experiment was conducted on ice algal communities obtained from sea ice at Saroma-Ko Lagoon in Hokkaido, Japan. Photoprotective responses to direct sunlight were examined through non-photochemical quenching (NPQ) of chlorophyll fluorescence and xanthophyll pigments. De-epoxidation of diadinoxanthin (DD) to diatoxanthin (DT) occurred rapidly, and NPQ showed a dynamic response to high light exposure. The linear relationship between the ratio of DT to chlorophyll a and NPQ followed a steeper slope than previously observed for mesophilic diatoms. The steeper slope could be explained by an apparent increase in DT for the mesophilic diatoms and induction of NPQ in response to low temperatures only in the ice algal communities. Enhanced production of DT in mesophilic diatoms could be the result of de-epoxidation of DD plus de novo synthesis, and the enhancement of NPQ might be caused by low temperature stress in the ice algae. Although the response of NPQ might be related to temperature, NPQ independent of DT synthesis should also be studied.     

Organization of cortical processing for facial movements during licking in cats

We proposed that cortical organization for the execution of adequate licking in cats was processed under the control of two kinds of affiliated groups for face and jaw & tongue movements (Hiraba H, Sato T. 2005A. Cerebral control of face, jaw, and tongue movements in awake cats: Changes in regional cerebral blood flow during lateral feeding Somatosens Mot Res 22:307–317). We assumed the cortical organization for face movements from changes in MRN (mastication-related neuron) activities recorded at area M (motor cortex) and orofacial behaviors after the lesion in the facial SI (facial region in the primary somatosensory cortex). Although we showed the relationship between facial SI (area 3b) and area M (area 4δ), the property of area C (area 3a) was not fully described. The aim of this present study is to investigate the functional role of area C (the anterior part of the coronal sulcus) that transfers somatosensory information in facial SI to area M, as shown in a previous paper (Hiraba H. 2004. The function of sensory information from the first somatosensory cortex for facial movements during ingestion in cats Somatosens Mot Res 21:87--97). We examined the properties of MRNs in area C and changes in orofacial behaviors after the area C or area M lesion. MRNs in area C had in common RFs in the lingual, perioral, and mandibular parts, and activity patterns of MRNs showed both post- and pre-movement types. Furthermore, cats with the area C lesion showed similar disorders to cats with the area M lesion, such as the dropping of food from the contralateral mouth, prolongation of the period of ingestion and mastication, and so on. From these results, we believe firmly the organization of unilateral cortical processing in facial SI, area C, and area M for face movements during licking.     

Human Pluripotent Stem Cell-Derived Tumor Model Uncovers the Embryonic Stem Cell Signature as a Key Driver in Atypical Teratoid/Rhabdoid Tumor

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The role of TGF-beta signaling in regulating chondrogenesis and osteogenesis during mandibular development

During craniofacial development, Meckel's cartilage and the mandible bone derive from the first branchial arch, and their development depends upon the contribution of cranial neural crest (CNC) cells. We previously demonstrated that conditional inactivation of Tgfbr2 in the neural crest of mice (Tgfbr2^fl/fl;Wnt1-Cre) results in severe defects in mandibular development, although the specific cellular and molecular mechanisms by which TGF-β signaling regulates the fate of CNC cells during mandibular development remain unknown. We show here that loss of Tgfbr2 does not affect the migration of CNC cells during mandibular development. TGF-β signaling is specifically required for cell proliferation in Meckel's cartilage and the mandibular anlagen and for the formation of the coronoid, condyle and angular processes. TGF-β-mediated connective tissue growth factor (CTGF) signaling is critical for CNC cell proliferation. Exogenous CTGF rescues the cell proliferation defect in Meckel's cartilage of Tgfbr2^fl/fl;Wnt1-Cre mutants, demonstrating the biological significance of this signaling cascade in chondrogenesis during mandibular development. Furthermore, TGF-β signaling controls Msx1 expression to regulate mandibular osteogenesis as Msx1 expression is significantly reduced in Tgfbr2^fl/fl;Wnt1-Cre mutants. Collectively, our data suggest that there are differential signal cascades in response to TGF-β to control chondrogenesis and osteogenesis during mandibular development.