Kazutomo Toyofuku

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Oculocutaneous albinism (OCA) is caused by reduced or deficient melanin pigmentation in the skin, hair, and eyes. OCA has different phenotypes resulting from mutations in distinct pigmentation genes involved in melanogenesis. OCA type 2 (OCA2), the most common form of OCA, is an autosomal recessive disorder caused by mutations in the P gene, the function(s)(More)
Various types of oculocutaneous albinism (OCA) are associated with reduced pigmentation in the skin, hair, and eyes that results from mutations in genes involved in melanin synthesis. Immortal mouse melanocyte lines (melan-a, melan-b, and melan-c) provide opportune models with which to investigate the etiology of two different types of OCA (types I and(More)
In response to agouti signal protein, melanocytes switch from producing eumelanin to pheomelanin concomitant with the down-regulation of melanogenic gene transcription. We previously reported that a ubiquitous basic helix-loop-helix transcription factor, known as ITF2, is up-regulated during this switch, and we now report that treatment of melanocytes with(More)
Tyrosinase-related protein (TRP)-1 is one of the most abundant melanosomal glycoproteins involved in melanogenesis. This report summarizes our recent research efforts related to the biological role and biosynthesis of TRP-1 and its transport from TGN (trans-Golgi network) to the stage I melanosome. Our UV irradiation and tyrosinase and TRP-1 cDNA(More)
In this study, we used melb-a melanoblasts as a model to study mechanisms involved in stimulating melanocyte function in vitiliginous skin following exposure to 8-methoxypsoralen (8MOP). Melanin content and tyrosinase activity increased 3- and 7-fold, respectively, in melanoblasts treated with 8MOP for 6 d compared with untreated controls. The intracellular(More)
The murine melanoma cell line BL-6-beta m, which is a stable cell line transfected with a gene coding a unique actin subspecies called beta m to the BL-6 cell line, has low metastatic potentials as compared with those of the parent cell line. BL-6-beta m melanomas were found to be sensitive to in vivo local injection of IL-2, while BL-6 melanomas showed(More)
Oculocutaneous albinism type 1 (OCA1) is an autosomal recessive disease resulting from mutations of the tyrosinase gene (TYR). To elucidate the molecular basis of OCA1 phenotypes, we analysed the early processing and maturation of several different types of mutant tyrosinase with various degrees of structural abnormalities (i.e. two large deletion mutants,(More)
Assembly, target-signaling and transport of tyrosinase gene family proteins at the initial stage of melanosome biogenesis are reviewed based on our own discoveries. Melanosome biogenesis involves four stages of maturation with distinct morphological and biochemical characteristics that reflect distinct processes of the biosynthesis of structural and(More)
We observed transient, erythematous skin eruptions in 6 patients during the intravenous administration of interferon (INF)-alpha for chronic active hepatitis C. The eruptions appeared 5 to 14 days (mean: 6.8 days) after initiating its administration. They were localized or disseminated and consisted of edematous, erythematous, and/or papular changes.(More)
Murine B16-F10 melanoma was treated with local microwave hyperthermia, local injection of murine recombinant interferon-beta (rIFN-beta) or a combination of both in order to investigate the augmentation of anti-proliferative effects with this combination treatment. Concerning the local modulation of immunological reactions of the host, local hyperthermia at(More)