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Human Embryonic Stem Cells in Culture Possess Primary Cilia with Hedgehog Signaling Machinery
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.576.3
Subject(s) - smoothened , cilium , hedgehog , hedgehog signaling pathway , microbiology and biotechnology , biology , embryonic stem cell , patched , intraflagellar transport , signal transduction , genetics , flagellum , gene
Human embryonic stem cells (hESCs) are potential therapeutic tools and models of tissue differentiation and development. With growing interest in (1) primary cilia in signal transduction pathways crucial for embryological development and tissue differentiation and (2) mechanisms regulating human hESC differentiation, the existence of primary cilia and the localization of signaling components in undifferentiated hESC establish a mechanistic basis for the regulation of hESC differentiation. Using electron (EM), immunofluorescence and confocal microscopies, we show that primary cilia are present in three undifferentiated hESC lines. EM reveals the characteristic 9+0 axoneme. The number and length of cilia increase after serum starvation. Important components of the hedgehog pathway, such as smoothened, patched and Gli2, are present in the cilia, and stimulation of the pathway results in the concerted movement of patched out of, and smoothened into, the primary cilium. These findings (1) show that hESC contain primary cilia associated with working hedgehog machinery; and (2) indicate endogenous hedgehog signaling in hESC.