Chieko Koike

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Understanding the molecular mechanisms by which distinct cell fate is determined during organogenesis is a central issue in development and disease. Here, using conditional gene ablation in mice, we show that the transcription factor Otx2 is essential for retinal photoreceptor cell fate determination and development of the pineal gland. Otx2-deficiency(More)
An essential step in intricate visual processing is the segregation of visual signals into ON and OFF pathways by retinal bipolar cells (BCs). Glutamate released from photoreceptors modulates the photoresponse of ON BCs via metabotropic glutamate receptor 6 (mGluR6) and G protein (Go) that regulates a cation channel. However, the cation channel has not yet(More)
Overproduction of the ornithine decarboxylase (ODC) regulatory protein ODC-antizyme has been shown to correlate with cell growth inhibition in a variety of different cell types. Although the exact mechanism of this growth inhibition is not known, it has been attributed to the effect of antizyme on polyamine metabolism. Antizyme binds directly to ODC,(More)
We previously reported that Otx2 is essential for photoreceptor cell fate determination; however, the functional role of Otx2 in postnatal retinal development is still unclear although it has been reported to be expressed in retinal bipolar cells and photoreceptors at postnatal stages. In this study, we first examined the roles of Otx2 in the terminal(More)
MicroRNA-124a (miR-124a) is the most abundant microRNA expressed in the vertebrate CNS. Despite past investigations into the role of miR-124a, inconsistent results have left the in vivo function of miR-124a unclear. We examined the in vivo function of miR-124a by targeted disruption of Rncr3 (retinal non-coding RNA 3), the dominant source of miR-124a.(More)
Crx, an Otx-like homeobox gene, is expressed primarily in the photoreceptors of the retina and in the pinealocytes of the pineal gland. The CRX homeodomain protein is a transactivator of many photoreceptor/pineal-specific genes in vivo, such as rhodopsin and the cone opsins. Mutations in Crx are associated with the retinal diseases, cone-rod dystrophy-2,(More)
The transient receptor potential (TRP) channels affect essential functions widely in sensory systems of various species, both invertebrates and vertebrates. The channel protein encoded by the trp gene, the first identified TRP superfamily molecule, is known to mediate the Drosophila light response. A vertebrate TRP channel playing a crucial role in the(More)
Mutations in TRPM1 are found in humans with an autosomal recessive form of complete congenital stationary night blindness (cCSNB). The Trpm1(-/-) mouse has been an important animal model for this condition. Here we report a new mouse mutant, tvrm27, identified in a chemical mutagenesis screen. Genetic mapping of the no b-wave electroretinogram (ERG)(More)
PURPOSE To identify human transient receptor potential cation channel, subfamily M, member 1 (TRPM1) gene mutations in patients with congenital stationary night blindness (CSNB). METHODS We analyzed four different Japanese patients with complete CSNB in whom previous molecular examination revealed no mutation in either nyctalopin (NYX) or glutamate(More)
To clarify the function of integrin alpha(v)beta3 in the early stage of liver metastasis, we investigated the interactions of metastatic cells with their target organ under the actual blood flow by using positron emission tomography (PET). The cells used were CHO-K1 cells and their transfectants bearing human integrin alpha(v)beta3 cDNA(More)