記述言語：英語   掲載種別：研究論文（学術雑誌）  

Glycosphingolipids are involved in intercellular signaling, adhe-sion, proliferation, and differentiation. Saposins A, B, C, and D are cofactors required for glycosphingolipid hydrolysis. Saposins A-D are present in series in a common precursor protein, prosaposin. Thus, glycosphingolipids amounts depend on prosaposin cellular levels. We previously reported that prosaposin and saposin B bind coenzyme Q10 in human cells. Coenzyme Q10 is an essential lipid of the mitochondrial electron transport system, and its reduced form is an important antioxidant. Coenzyme Q10 level decrease in aging and in various progressive diseases. Therefore, it is interesting to understand the cellular response to long-term coenzyme Q10 deficiency. We established a long-term coenzyme Q10 deficient cell model by using the coenzyme Q10 biosynthesis inhibitor, 4-nitrobenzoate. The levels of coenzyme Q10 were reduced by 4-nitrobenzoate in HepG2 cells. Administration of 4-nitrobenzoate also decreased prosaposin protein and mRNA levels. The cellular levels of coenzyme Q10 and prosaposin were recovered by treatment with 4-hydroxybenzoquinone, a substrate for coenzyme Q10 synthesis that counteracts the effect of 4-nitrobenzoate. Furthermore, the ganglioside levels were altered in 4-nitrobenzoate treated cells. These results imply that long-term coenzyme Q10 deficiency reduces cellular prosaposin levels and disturbs glycosphingolipid metabolism.

DOI： 10.3164/jcbn.21-126

PubMed

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Coenzyme Q10 is an important molecule for mitochondrial respiration and as an antioxidant. Maintenance of the ovum in a good condition is considered to be important for successful fertilization and development, which has been reported to be promoted by coenzyme Q10. In this study, we investigated the level of coenzyme Q10 during ovum fertilization and maturation. We attempted to analyze coenzyme Q10 levels during ovum development in species that use coenzyme Q10 but not coenzyme Q9. It was shown that medaka produces coenzyme Q10. We then measured the amount of coenzyme Q10 after fertilization of medaka ovum and found that it increased. The amount of free cholesterol biosynthesized from acetyl CoA as well as coenzyme Q10 increased during development, but the increase in coenzyme Q10 was more pronounced. The mRNA expression level of coq9 also increased during embryonic development, but the mRNA expression levels of other coenzyme Q10 synthases did not. These results suggest that the coq9 gene is upregulated during the development of medaka ovum after fertilization, resulting in an increase in the amount of coenzyme Q10 in the ovum. Medaka, which like humans has coenzyme Q10, is expected to become a model animal for coenzyme Q10 research.

DOI： 10.3164/jcbn.21-148

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.abb.2021.108988

開催年月日： 2022年

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開催年月日： 2022年

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開催年月日： 2022年

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記述言語：日本語  

記述言語：英語  

記述言語：日本語  

記述言語：日本語  

記述言語：日本語  

記述言語：日本語  

記述言語：日本語  

会議種別：口頭発表（一般）  

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会議種別：ポスター発表  

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会議種別：口頭発表（一般）  

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