Organization of the Indian hedgehog--parathyroid hormone-related protein system in the postnatal growth plate.

Michael Chau, Patricia Forcinito, Anenisia C. Andrade, Anita Hegde, Sohyun Ahn, Julian C. Lui, Jeffrey Baron, Ola Nilsson

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

In embryonic growth cartilage, Indian hedgehog (Ihh) and parathyroid hormone-related protein (PTHrP) participate in a negative feedback loop that regulates chondrocyte differentiation. Postnatally, this region undergoes major structural and functional changes. To explore the organization of the Ihh-PTHrP system in postnatal growth plate, we microdissected growth plates of 7-day-old rats into their constituent zones and assessed expression of genes participating in the h-PTHrP feedback loop. Ihh, Patched 1, Smoothened, Gli1, Gli2, Gli3, and Pthr1 were expressed in regions analogous to the expression domains in embryonic growth cartilage. However, PTHrP was expressed in resting zone cartilage, a site that differs from the embryonic source, the periarticular cells. We then used mice in which lacZ has replaced coding sequences of Gli1 and thus serves as a marker for active hedgehog signaling. At 1, 4, 8, and 12 weeks of age, lacZ expression was detected in a pattern analogous to that of embryonic cartilage. The findings support the hypothesis that the embryonic Ihh-PTHrP feedback loop is maintained in the postnatal growth plate except that the source of PTHrP has shifted to a more proximal location in the resting zone.

Original languageEnglish (US)
Pages (from-to)99-107
Number of pages9
JournalJournal of Molecular Endocrinology
Volume47
Issue number1
DOIs
Publication statusPublished - 2011

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ASJC Scopus subject areas

  • Endocrinology
  • Molecular Biology

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