title: A high-fat diet reduces ceramide synthesis by decreasing adiponectin levels and decreases lipid content by modulating HMG-CoA reductase and CPT-1 mRNA expression in the skin.
abstract: METHODS
  Molecules involved in skin function are greatly affected by nutritional conditions. However, the mechanism linking high-fat (HF) diets with these alterations is not well understood. This study aimed to investigate the molecular changes in skin function that result from HF diets.
  
  
  RESULTS
  Sprague-Dawley rats were fed HF diets for 28 days. The skin levels of ceramide, lipids and mRNAs involved in lipid metabolism were evaluated using TLC, oil red O staining and quantitative PCR, respectively. The serum adiponectin concentration was determined by ELISA. HF diets led to reduced ceramide levels and lowered skin lipid content. They also decreased mRNA levels of serine palmitoyltransferase (SPT) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in the skin and those of peroxisome proliferator-activated receptor-α -PPAR-α), which upregulates SPT and HMG-CoA reductase expression. The HF diets reduced the serum concentration of adiponectin, which acts upstream of PPAR-α. Finally, these diets led to increased mRNA levels of carnitine palmitoyltransferase-1, the rate-limiting enzyme that acts in β-oxidation.
  
  
  CONCLUSIONS
  Our study suggests that HF diets reduce ceramide and lipid synthesis in the skin by reducing levels of SPT and HMG-CoA reductase through lowered adiponectin and PPAR-α activity. Additionally, they decrease lipid content by enhancing β-oxidation.
authors: Department of Nutritional Sciences, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo, Japan. y3oishi@nodai.ac.jp
authors: Takumi
authors: T
authors: Yamane
authors: Kazuo
authors: K
authors: Kobayashi-Hattori
authors: Yuichi
authors: Y
authors: Oishi
mesh_terms: D052242:Adiponectin / Q000097:blood* / Q000378:metabolism; D000818:Animals; D001835:Body Weight; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics* / Q000378:metabolism; D002518:Ceramides / Q000096:biosynthesis*; D059305:Diet, High-Fat; D002149:Energy Intake; D005786:Gene Expression Regulation; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics* / Q000378:metabolism; D050356:Lipid Metabolism; D008055:Lipids / Q000097:blood*; D008297:Male; D047493:PPAR alpha / Q000378:metabolism; D012333:RNA, Messenger; D051381:Rats; D017207:Rats, Sprague-Dawley; D051102:Serine C-Palmitoyltransferase / Q000235:genetics* / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics; D051782:Sterol Regulatory Element Binding Protein 2 / Q000235:genetics
chemical_list: D052242:Adiponectin; D002518:Ceramides; D008055:Lipids; D047493:PPAR alpha; D012333:RNA, Messenger; C497389:Srebf1 protein, rat; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D006903:Hydroxymethylglutaryl CoA Reductases; D002334:Carnitine O-Palmitoyltransferase; D051102:Serine C-Palmitoyltransferase