Lrp4/Wise regulates palatal rugae development through Turing-type reaction-diffusion mechanisms

PLoS One. 2018 Sep 20;13(9):e0204126. doi: 10.1371/journal.pone.0204126. eCollection 2018.

Abstract

Periodic patterning of iterative structures is diverse across the animal kingdom. Clarifying the molecular mechanisms involved in the formation of these structure helps to elucidate the process of organogenesis. Turing-type reaction-diffusion mechanisms have been shown to play a critical role in regulating periodic patterning in organogenesis. Palatal rugae are periodically patterned ridges situated on the hard palate of mammals. We have previously shown that the palatal rugae develop by a Turing-type reaction-diffusion mechanism, which is reliant upon Shh (as an inhibitor) and Fgf (as an activator) signaling for appropriate organization of these structures. The disturbance of Shh and Fgf signaling lead to disorganized palatal rugae. However, the mechanism itself is not fully understood. Here we found that Lrp4 (transmembrane protein) was expressed in a complementary pattern to Wise (a secreted BMP antagonist and Wnt modulator) expression in palatal rugae development, representing Lrp4 expression in developing rugae and Wise in the inter-rugal epithelium. Highly disorganized palatal rugae was observed in both Wise and Lrp4 mutant mice, and these mutants also showed the downregulation of Shh signaling, which was accompanied with upregulation of Fgf signaling. Wise and Lrp4 are thus likely to control palatal rugae development by regulating reaction-diffusion mechanisms through Shh and Fgf signaling. We also found that Bmp and Wnt signaling were partially involved in this mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Body Patterning* / genetics
  • Bone Morphogenetic Proteins / genetics
  • Bone Morphogenetic Proteins / metabolism*
  • Diffusion
  • Gene Expression Regulation, Developmental
  • LDL-Receptor Related Proteins
  • Mice
  • Mice, Mutant Strains
  • Palate, Hard / embryology*
  • Palate, Hard / metabolism*
  • Palate, Hard / pathology
  • Phenotype
  • Receptors, LDL / genetics
  • Receptors, LDL / metabolism*
  • Signal Transduction

Substances

  • Adaptor Proteins, Signal Transducing
  • Bone Morphogenetic Proteins
  • LDL-Receptor Related Proteins
  • Lrp4 protein, mouse
  • Receptors, LDL
  • Sostdc1 protein, mouse

Grants and funding

This research was funded by the Japan Society for the Promotion of Science (JSPS; 17H06278).