Genetic mutation analysis in Japanese patients with non-syndromic congenital heart disease.

Congenital heart disease (CHD) is the most common birth defect occurring in humans and some transcriptional factors have been identified as causative. However, additional mutation analysis of these genes is necessary to develop effective diagnostic and medical treatment methods. We conducted sequence analysis of the coding regions of NKX2.

Morphogenetic roles of perlecan in the tooth enamel organ: an analysis of overexpression using transgenic mice.

Perlecan, a heparan sulfate proteoglycan, is enriched in the intercellular space of the enamel organ. To understand the role of perlecan in tooth morphogenesis, we used a keratin 5 promoter to generate transgenic (Tg) mice that over-express perlecan in epithelial cells, and examined their tooth germs at tissue and cellular levels. Immunohistochemistry showed that perlecan was more strongly expressed in the enamel organ cells of Tg mice than in wild-type mice.

Differential proteomic shotgun analysis elucidates involvement of water channel aquaporin 8 in presence of α-amylase in the colon.

Aquaporin (AQP) family plays a pivotal role in fluid secretion and absorption, especially in the digestive system and secretory glands. Within this family, AQP8 was reported to be widely expressed in the epithelia of the digestive tract, liver, and pancreas. In two parallel experimental platforms with different analytical and comparative approaches, in-gel tryptic digestion with macro-embedded spreadsheet analysis and in-solution tryptic digestion with LC-MS alignment based approach, we compared wild-type and AQP8 knockout mice colon proteomes.

Odontogenic potential of post-natal oral mucosal epithelium.

A bioengineered tooth would provide a powerful alternative to currently available clinical treatments. Previous experiments have succeeded in bioengineering teeth using tooth germs from animal embryos. However, the ultimate goal is to develop a technology which enables teeth to be regenerated with the use of autologous cells.

Spatial resolution of calpain-catalyzed proteolysis in focal cerebral ischemia.

Transient forebrain ischemia induces calpain-mediated degradation of the neuronal cytoskeleton, alpha-fodrin, and this results in ischemic neuronal death. In this study, we investigated the spatial distribution and temporal changes of calpain-catalyzed alpha-fodrin proteolysis in focal cerebral ischemia and examined the effects of a calpain inhibitor. Ischemia was induced in gerbils by 3-h middle cerebral artery occlusion followed by reperfusion.

Calpain induces proteolysis of neuronal cytoskeleton in ischemic gerbil forebrain.

We investigated the relationship between the activity of calcium-dependent protease (calpain) and the ischemic neuronal damage. We also investigated the mechanism of ischemic resistance in astrocytes. In gerbil, a 10-min forebrain ischemia was induced by occlusion of both common carotid arteries.

Msx2 deficiency in mice causes pleiotropic defects in bone growth and ectodermal organ formation.

The composite structure of the mammalian skull, which forms predominantly via intramembranous ossification, requires precise pre- and post-natal growth regulation of individual calvarial elements. Disturbances of this process frequently cause severe clinical manifestations in humans. Enhanced DNA binding by a mutant MSX2 homeodomain results in a gain of function and produces craniosynostosis in humans.

Middle ear defects associated with the double knock out mutation of murine goosecoid and Msx1 genes.

A number of developmental regulatory genes, including homeobox genes, are dynamically expressed in the mammalian cephalic ectomesenchyme during craniofacial morphogenesis. Owing to the vast amount of gene knock out experiments, functions of such genes are now being revealed in the mammalian skeletal patterning process. The murine goosecoid (Gsc) and Msx1 genes are expressed during craniofacial development and each mutant mouse displays intriguing facial abnormalities including those of middle ear ossicles, suggesting that both genes play roles in spatial programming of craniofacial regions.

Msx1 controls inductive signaling in mammalian tooth morphogenesis.

Members of the Msx homeobox family are thought to play important roles in inductive tissue interactions during vertebrate organogenesis, but their precise developmental function has been unclear. Mice deficient for Msx1 exhibit defects in craniofacial development and a failure of tooth morphogenesis, with an arrest in molar tooth development at the E13.5 bud stage.

Mechanisms of reduced fertility in Hoxa-10 mutant mice: uterine homeosis and loss of maternal Hoxa-10 expression.

The establishment of a receptive uterine environment is critical for embryonic survival and implantation. One gene that is expressed in the uterus during the peri-implantation period in mice and is required for female fertility is the homeobox gene Hoxa-10. Here we characterize the peri-implantation defects in Hoxa-10 mutant females and investigate functions of Hoxa-10 in the uterine anlage during morphogenesis and in the adult uterus during pregnancy.

A gene trap strategy for identifying the gene expressed in the embryonic nervous system.

An efficient gene trap strategy was devised for identifying the genes that are expressed in the mouse developing nervous system. Mouse embryonic stem (ES) cell lines that carried independent integrations of a gene trap vector, pSneolN/acZA, were allowed to differentiate in a suspension culture system. To select cells containing neurons, astrocytes or neuron-glia precursors, cell lines were immunohistochemically examined with antibodies against neuron-specific proteins (neurofilament protein 150 kD and microtubule associated protein 2), glial fibrillary acidic protein or nestin.

Sexually dimorphic sterility phenotypes in Hoxa10-deficient mice.

The Abdominal B (AbdB) genes constitute a distinct subfamily of homeobox genes that exhibit posterior domains of expression, including the genital imaginal disc in Drosophila and the developing urogenital system in vertebrates. We have mutated the AbdB gene Hoxa10 in mice. We report here that homozygotes are fully viable and show an anterior homeotic transformation of lumbar vertebrae.

Msx1 deficient mice exhibit cleft palate and abnormalities of craniofacial and tooth development.

The Msx1 homeobox gene is expressed at diverse sites of epithelial-mesenchymal interaction during vertebrate embryogenesis, and has been implicated in signalling processes between tissue layers. To determine the phenotypic consequences of its deficiency, we prepared mice lacking Msx1 function. All Msx1- homozygotes manifest a cleft secondary palate, a deficiency of alveolar mandible and maxilla and a failure of tooth development.

Genomic characterization of the human DNA excision repair-controlling gene XPAC.

We have characterized the human DNA excision repair gene, XPAC (xeroderma pigmentosum group A complementing). This gene of approximately 25 kb consists of six exons. The 5'-flanking region of the gene has a CAAT box, but no TATA box.

Erythrocyte Na/K flux ratio in relation to sodium intake and a family history of essential hypertension in normotensive children.

Erythrocyte Na/K flux ratio was examined in relation to a family history of essential hypertension (FH-HT) and plasma and urine electrolytes in 84 normotensive children (13-15 yrs old), and in relation to sodium intake in six children with acute glomerulonephritis or IgA nephropathy who had normal renal function (6-13 yrs old). Erythrocyte Na/K flux ratio was significantly lower in children with a family history of essential hypertension than in those without. Plasma and urine electrolytes (Na and K) showed no significant differences between children with and without a family history of essential hypertension, although erythrocyte Na/K flux ratio was negatively correlated with serum K level in the whole group.

Identification of splicing mutations of the last nucleotides of exons, a nonsense mutation, and a missense mutation of the XPAC gene as causes of group A xeroderma pigmentosum.

Four mutations of the XPAC gene were identified as molecular bases of different UV-sensitive subgroups of xeroderma pigmentosum (XP) group A. One was a G to C transversion at the last nucleotide of exon 4 in GM1630/GM2062, a little less hypersensitive subgroup than the most sensitive XP2OS/XP12RO. The second mutation was a G to A transition at the last nucleotide of exon 3 in GM2033/GM2090, an intermediate subgroup.

Three nonsense mutations responsible for group A xeroderma pigmentosum.

The molecular basis of xeroderma pigmentosum (XP) group A was studied and 3 nonsense mutations of the XP-A complementing gene (XPAC) were identified. One was a nucleotide transition altering the Arg-228 codon (CGA) to a nonsense codon (TGA). This transition creates a new cleavage site for the restriction endonuclease HphI.

Molecular basis of group A xeroderma pigmentosum: a missense mutation and two deletions located in a zinc finger consensus sequence of the XPAC gene.

The molecular basis of group A xeroderma pigmentosum (XP) was investigated, and 3 mutations located in a zinc finger consensus sequence (nucleotide 313-387) of the XP group A complementing (XPAC) gene were identified in 2 Caucasian patients GM2990 and GM2009 who had typical symptoms of group A XP. The first mutation was a C deletion at nucleotide 374. Patient GM2990 was a homozygote for this mutation.