Thyroid hormone-induced sonic hedgehog signal up-regulates its own pathway in a paracrine manner in the Xenopus laevis intestine during metamorphosis

Authors

  • Takashi Hasebe,

    Corresponding author
    1. Department of Biology, Nippon Medical School, Nakahara-ku, Kawasaki, Kanagawa, Japan
    • Department of Biology, Nippon Medical School, 2-297-2 Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa 211-0063, Japan
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  • Mitsuko Kajita,

    1. Department of Molecular Biology, Institute of Development and Aging Sciences, Nippon Medical School, Nakahara-ku, Kawasaki, Kanagawa, Japan
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  • Liezhen Fu,

    1. Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
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  • Yun-Bo Shi,

    1. Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
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  • Atsuko Ishizuya-Oka

    1. Department of Biology, Nippon Medical School, Nakahara-ku, Kawasaki, Kanagawa, Japan
    2. Department of Molecular Biology, Institute of Development and Aging Sciences, Nippon Medical School, Nakahara-ku, Kawasaki, Kanagawa, Japan
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Abstract

Background: During Xenopus laevis metamorphosis, Sonic hedgehog (Shh) is directly induced by thyroid hormone (TH) at the transcription level as one of the earliest events in intestinal remodeling. However, the regulation of other components of this signaling pathway remains to be analyzed. Here, we analyzed the spatiotemporal expression of Patched (Ptc)-1, Smoothened (Smo), Gli1, Gli2, and Gli3 during natural and TH-induced intestinal remodeling. Results: We show that all of the genes examined are transiently up-regulated in the mesenchymal tissues during intestinal metamorphosis. Conclusions: Interestingly, in the presence of protein synthesis inhibitors, Gli2 but not the others was induced by TH, suggesting that Gli2 is a direct TH response gene, while the others are likely indirect ones. Furthermore, we demonstrate by the organ culture experiment that overexpression of Shh enhances the expression of Ptc-1, Smo, and Glis even in the absence of TH, indicating that Shh regulates its own pathway components during intestinal remodeling. Developmental Dynamics 241:403–414, 2012. © 2011 Wiley Periodicals, Inc.

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