MITF-M regulates melanogenesis in mouse melanocytes

J Dermatol Sci. 2018 Jun;90(3):253-262. doi: 10.1016/j.jdermsci.2018.02.008. Epub 2018 Feb 19.

Abstract

Background: Although the impact of the microphthalamia-associated transcription factor (Mitf) signaling pathway on melanocytes progression has been extensively studied, the specific molecular mechanisms behind MITF-M-enhanced melanin production in melanocytes still need to be clarified.

Methods: In this study, we analyzed the levels of Mitf-M in skin tissues of different coat mice in order to further reveal the relationship between Mitf-M and skin pigmentation. To address the function of Mitf-M on melanogenesis, we have used an overexpression system and combined morphological and biochemical methods to investigate its localization in different coat color mice and pigmentation-related genes' expression in mouse melanocytes.

Results: The qRT-PCR assay and Western blotting analysis revealed that Mitf-M mRNA and protein were synthesized in all tested mice skin samples, with the highest expression level in brown skin, a moderate expression level in grey skin and the lowest expression level in black skin. Simultaneously, immunofluorescence staining revealed that MITF-M was mainly expressed in the hair follicle matrix and inner and outer root sheath in the skin tissues with different coat colors. Furthermore, overexpression of MITF-M led to increased melanin content and variable pigmentation-related gene expression.

Conclusion: These results directly demonstrate that MITF-M not only influences melanogenesis, but also determines the progression of melanosomal protein in mouse melanocytes.

Keywords: Melanocytes; Melanogenesis; Mitf-M.

MeSH terms

  • Animals
  • Hair Follicle / metabolism
  • Intramolecular Oxidoreductases / genetics
  • Intramolecular Oxidoreductases / metabolism
  • Melanins / biosynthesis*
  • Melanocytes / metabolism*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Microphthalmia-Associated Transcription Factor / physiology*
  • Monophenol Monooxygenase / genetics
  • Monophenol Monooxygenase / metabolism
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism
  • RNA, Messenger / metabolism
  • Signal Transduction / physiology
  • Skin Pigmentation / genetics
  • Skin Pigmentation / physiology*
  • Up-Regulation

Substances

  • MIRN137 microRNA, mouse
  • Melanins
  • Membrane Glycoproteins
  • MicroRNAs
  • Microphthalmia-Associated Transcription Factor
  • Mitf protein, mouse
  • RNA, Messenger
  • Oxidoreductases
  • Tyrp1 protein, mouse
  • Monophenol Monooxygenase
  • Intramolecular Oxidoreductases
  • dopachrome isomerase