Transcriptional profiling shows altered expression of wnt pathway- and lipid metabolism-related genes as well as melanogenesis-related genes in melasma

J Invest Dermatol. 2011 Aug;131(8):1692-700. doi: 10.1038/jid.2011.109. Epub 2011 May 12.

Abstract

Melasma is a commonly acquired hyperpigmentary disorder of the face, but its pathogenesis is poorly understood and its treatment remains challenging. We conducted a comparative histological study on lesional and perilesional normal skin to clarify the histological nature of melasma. Significantly, higher amounts of melanin and of melanogenesis-associated proteins were observed in the epidermis of lesional skin, and the mRNA level of tyrosinase-related protein 1 was higher in lesional skin, indicating regulation at the mRNA level. However, melanocyte numbers were comparable between lesional and perilesional skin. A transcriptomic study was undertaken to identify genes involved in the pathology of melasma. A total of 279 genes were found to be differentially expressed in lesional and perilesional skin. As was expected, the mRNA levels of a number of known melanogenesis-associated genes, such as tyrosinase, were found to be elevated in lesional skin. Bioinformatics analysis revealed that the most lipid metabolism-associated genes were downregulated in lesional skin, and this finding was supported by an impaired barrier function in melasma. Interestingly, a subset of Wnt signaling modulators, including Wnt inhibitory factor 1, secreted frizzled-related protein 2, and Wnt5a, were also found to be upregulated in lesional skin. Immunohistochemistry confirmed the higher expression of these factors in melasma lesions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Adult
  • Frizzled Receptors / genetics
  • Frizzled Receptors / metabolism
  • Gene Expression Profiling*
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization
  • Lipid Metabolism / genetics*
  • Melanocytes / physiology
  • Melanosis / genetics*
  • Melanosis / metabolism*
  • Melanosis / pathology
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism
  • Middle Aged
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Wnt Proteins / genetics*
  • Wnt Proteins / metabolism*
  • Wnt-5a Protein
  • Wnt1 Protein / genetics
  • Wnt1 Protein / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • FZD2 protein, human
  • Frizzled Receptors
  • Membrane Glycoproteins
  • Proto-Oncogene Proteins
  • Receptors, G-Protein-Coupled
  • Repressor Proteins
  • WIF1 protein, human
  • WNT5A protein, human
  • Wnt Proteins
  • Wnt-5a Protein
  • Wnt1 Protein
  • Oxidoreductases
  • TYRP1 protein, human