Laminin-511 Is an Epithelial Message Promoting Dermal Papilla Development and Function During Early Hair Morphogenesis

The document from 2008 presents a study on the role of laminin-511 in hair follicle development, with a focus on its impact on dermal papilla (DP) development and function during early hair morphogenesis. The study found that laminin-511 is essential for maintaining the expression of key morphogens like noggin and sonic hedgehog (Shh), which are necessary for hair follicle development. Laminin-511 mutants exhibited defects in DP development, including reduced primary cilia length and structure, which are important for signal transduction. The study also showed that the β1 integrin binding domain of laminin-511 is required for hair development, while the heparin binding domain is not. Furthermore, laminin-511, but not laminin-111, could restore primary cilia formation and trigger noggin expression in a Shh- and PDGF-dependent manner. Inhibition of the laminin-511 receptor β1 integrin disrupted DP primary cilia formation and hair development, indicating that epithelial-derived laminin-511 is a critical early signal for ciliary function and DP maintenance in hair follicle downgrowth. The study did not specify the number of subjects used in the experiments.