| First Author | Karlsson L | Year | 1999 |
| Journal | Development | Volume | 126 |
| Issue | 12 | Pages | 2611-21 |
| PubMed ID | 10331973 | Mgi Jnum | J:54912 |
| Mgi Id | MGI:1336614 | Doi | 10.1242/dev.126.12.2611 |
| Citation | Karlsson L, et al. (1999) Roles for PDGF-A and sonic hedgehog in development of mesenchymal components of the hair follicle. Development 126(12):2611-21 |
| abstractText | Skin appendages, such as hair, develop as a result of complex reciprocal signaling between epithelial and mesenchymal cells. These interactions are not well understood at the molecular level. Platelet-derived growth factor-A (PDGF-A) is expressed in the developing epidermis and hair follicle epithelium, and its receptor PDGF-Ra is expressed in associated mesenchymal structures. Here we have characterized the skin and hair phenotypes of mice carrying a null mutation in the PDGF-A gene. Postnatal PDGF-A-/- mice developed thinner dermis, misshapen hair follicles, smaller dermal papillae, abnormal dermal sheaths and thinner hair, compared with mild-type siblings. BrdU labeling showed reduced cell proliferation in the dermis and in the dermal sheaths of PDGF-A -/- skin. PDGF-A -/- skin transplantation to nude mice led to abnormal hair formation, reproducing some of the features of the skin phenotype of PDGF-A-/- mice. Taken together, expression patterns and mutant phenotypes suggest that epidermal PDGF-A has a role in stimulating the proliferation of dermal mesenchymal cells that may contribute to the formation of dermal papillae, mesenchymal sheaths and dermal fibroblasts, Finally, we show that sonic hedgehog (shh)-/- mouse embryos have disrupted formation of dermal papillae, Such embryos fail to form pre-papilla aggregates of postmitotic PDGF-R alpha- positive cells, suggesting that shh has a critical role in the assembly of the dermal papilla. |
