Defining BMP functions in the hair follicle by conditional ablation of BMP receptor IA.

TitleDefining BMP functions in the hair follicle by conditional ablation of BMP receptor IA.
Publication TypeJournal Article
Year of Publication2003
AuthorsKobielak K, H Pasolli A, Alonso L, Polak L, Fuchs E
JournalJ Cell Biol
Volume163
Issue3
Pagination609-23
Date Published2003 Nov 10
ISSN0021-9525
KeywordsAnimals, Animals, Newborn, beta Catenin, Bone Morphogenetic Protein Receptors, Type I, Bone Morphogenetic Proteins, Carrier Proteins, Cell Differentiation, Cytoskeletal Proteins, DNA-Binding Proteins, Down-Regulation, Epidermis, GATA3 Transcription Factor, Gene Expression Regulation, Developmental, Hair Follicle, Lymphoid Enhancer-Binding Factor 1, Mice, Mice, Knockout, Microscopy, Electron, Protein-Serine-Threonine Kinases, Proteins, Proto-Oncogene Proteins, Receptors, Growth Factor, Skin Abnormalities, Stem Cells, Trans-Activators, Transcription Factors, Transplants, Vibrissae, Wnt Proteins, Zebrafish Proteins
Abstract

Using conditional gene targeting in mice, we show that BMP receptor IA is essential for the differentiation of progenitor cells of the inner root sheath and hair shaft. Without BMPRIA activation, GATA-3 is down-regulated and its regulated control of IRS differentiation is compromised. In contrast, Lef1 is up-regulated, but its regulated control of hair differentiation is still blocked, and BMPRIA-null follicles fail to activate Lef1/beta-catenin-regulated genes, including keratin genes. Wnt-mediated transcriptional activation can be restored by transfecting BMPRIA-null keratinocytes with a constitutively activated beta-catenin. This places the block downstream from Lef1 expression but upstream from beta-catenin stabilization. Because mice lacking the BMP inhibitor Noggin fail to express Lef1, our findings support a model, whereby a sequential inhibition and then activation of BMPRIA is necessary to define a band of hair progenitor cells, which possess enough Lef1 and stabilized beta-catenin to activate the hair specific keratin genes and generate the hair shaft.

DOI10.1083/jcb.200309042
Alternate JournalJ. Cell Biol.
PubMed ID14610062
PubMed Central IDPMC2173651