Role of large MAF transcription factors in the mouse endocrine pancreas

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Author(s)

    • ABDELLATIF Ahmed M. ABDELLATIF Ahmed M.
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan|Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Mansoura University, Elgomhouria Street, Mansoura, Dakahlyia 35516, Egypt
    • OGATA Kiyohito OGATA Kiyohito
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
    • XIAFUKAITI Gulibaikelamu
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
    • CHANG Yu-Hsin
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
    • KATOH Megumi C.
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
    • EL-MORSY Salah E.
    • Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Mansoura University, Elgomhouria Street, Mansoura, Dakahlyia 35516, Egypt
    • OISHI Hisashi
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan|Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
    • TAKAHASHI Satoru
    • Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan|Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan|International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan

Abstract

The members of the MAF family of transcription factors are homologs of v-Maf –the oncogenic component of the avian retrovirus AS42. The MAF family is subdivided into 2 groups, small and large MAFs. To elucidate the role of the large MAF transcription factors in the endocrine pancreas, we analyzed large MAF gene knockout mice. It has been shown that <i>Mafa<sup>−/−</sup></i> mice develop phenotypes including abnormal islet structure soon after birth. This study revealed that <i>Ins1</i> and <i>Ins2</i> transcripts and the protein contents were significantly reduced in <i>Mafa<sup>−/−</sup></i> mice at embryonic day 18.5. In addition, <i>Mafa<sup>−/−</sup></i>;<i>Mafb<sup>−/−</sup></i> mice contained less than 10% of the insulin transcript and protein of those of wild-type mice, suggesting that <i>Mafa</i> and <i>Mafb</i> cooperate to maintain insulin levels at the embryonic stage. On the other hand, the number of insulin-positive cells in <i>Mafa<sup>−/−</sup></i> mice was comparable to that of wild-type mice, and even under a <i>Mafb</i>-deficient background the number of insulin-positive cells was not decreased, suggesting that <i>Mafb</i> plays a dominant role in embryonic β-cell development. We also found that at 20 weeks of age <i>Mafa<sup>−/−</sup></i>;<i>Mafb<sup>+/−</sup></i> mice showed a higher fasting blood glucose level than single <i>Mafa<sup>−/−</sup></i> mice. In summary, our results indicate that <i>Mafa</i> is necessary for the maintenance of normal insulin levels even in embryos and that <i>Mafb</i> is important for the maintenance of fasting blood glucose levels in the <i>Mafa</i>-deficient background in adults.

Journal

  • Experimental Animals

    Experimental Animals 64(3), 305-312, 2015

    Japanese Association for Laboratory Animal Science

Codes

  • NII Article ID (NAID)
    130005091028
  • NII NACSIS-CAT ID (NCID)
    AA11032321
  • Text Lang
    ENG
  • ISSN
    1341-1357
  • NDL Article ID
    026603186
  • NDL Call No.
    Z54-H752
  • Data Source
    NDL  J-STAGE 
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