title: Upregulation of gene expression levels of ceramide metabolic enzymes after application of sphingomyelin-based liposomes to a three-dimensional cultured human epidermis model.
abstract: OBJECTIVE
  We have previously reported that the application of sphingomyelin-based liposomes (SM-L) to a three-dimensional cultured skin model increase the content of ceramides NS, NP, AS and AP. However, the mechanism responsible for these increased ceramide levels was not identified.
  
  
  METHODS
  SM-L and sphingomyelinase (SMase) were combined and incubated at 37 °C for 24 h. SM-L were also applied to three-dimensional cultured skin for 24 h and quantification of SMase and β-glucocerebrosidase (β-GCase) mRNA expression levels performed using real-time PCR. Additionally, three dimensional cultured skin was incubated with SM-L and the β-GCase inhibitor conduritol B epoxide (CBE) and the ceramide content determined by high performance thin layer chromatography.
  
  
  RESULTS
  We observed generation of ceramide NS after reaction of SM-L and SMase. However, the other ceramide classes were not detected. Notably, SMase and β-GCase mRNA expression levels were significantly increased in cells of the skin model following application of SM-L. The levels of ceramides NS, NP, AS and AP were decreased by treatment with CBE. However, only ceramide NS was significantly increased by treatment with CBE and SM-L in combination.
  
  
  CONCLUSIONS
  These findings indicate that application of SM-L to cultured skin upregulates the expression of SMase and β-GCase and increases ceramide content.
authors.affiliation: Laboratory of Dermatological Physiology, Faculty of Pharmaceutical Science, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan.
authors.forename: Yurina
authors.initials: Y
authors.lastname: Itaya
authors.affiliation: Laboratory of Dermatological Physiology, Faculty of Pharmaceutical Science, Josai University, 1-1 Keyakidai, Sakado, Saitama, 350-0295, Japan. Electronic address: tokudome@josai.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tokudome
mesh_terms: D002518:Ceramides / Q000096:biosynthesis*; D002851:Chromatography, High Pressure Liquid; D004817:Epidermis / Q000201:enzymology*; D020869:Gene Expression Profiling; D005962:Glucosylceramidase / Q000378:metabolism; D006801:Humans; D008081:Liposomes / Q000737:chemistry*; D060888:Real-Time Polymerase Chain Reaction; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013109:Sphingomyelins / Q000737:chemistry*; D046509:Tissue Culture Techniques / Q000379:methods*; D015533:Transcriptional Activation; D015854:Up-Regulation
chemical_list: D002518:Ceramides; D008081:Liposomes; D013109:Sphingomyelins; D013108:Sphingomyelin Phosphodiesterase; D005962:Glucosylceramidase
keywords: Ceramide; Sphingomyelin-based liposomes; Three-dimensional cultured skin epidermis model