title: Effect of n-3 polyunsaturated fatty acid on gene expression of the critical enzymes involved in homocysteine metabolism.
abstract: BACKGROUND
  Previous studies showed that plasma n-3 polyunsaturated fatty acid (PUFA) was negatively associated with plasma homocysteine (Hcy).
  
  
  OBJECTIVE
  We investigated the regulatory effect of n-3 PUFA on mRNA expression of the critical genes encoding the enzymes involved in Hcy metabolism.
  
  
  METHODS
  HepG2 cells were treated with docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), alpha-linolenic acid (ALA) respectively for 48 h. The cells were collected and total RNA was isolated. The mRNA expression levels of the genes were determined by using Real Time-PCR.
  
  
  RESULTS
  Compared with controls, the mRNA expression levels of 5-methyltetrahydrofolate reductase (MTHFR) were significantly increased in the DHA group (p < 0.05) and ALA group (p < 0.05); Significantly down-regulated mRNA expression of methionine adenosyltransferase (MAT) was observed with the treatments compared with the controls; the level of MAT expression was significant lower in the DHA group than the ALA group (p < 0.05); Cystathionine-γ-lyase (CSE) expression was significantly increased in the DHA (p < 0.05) and EPA groups (p < 0.05) compared with control. No significant changes were shown in mRNA expression levels of S-adenosylhomocysteine hydrolases (SAHH), cystathionine β-synthase (CBS), and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR).
  
  
  CONCLUSIONS
  Our results suggest that DHA up-regulates CSE and MTHFR mRNA expression and down-regulates MAT mRNA expression involved in Hcy metabolism.
authors.affiliation: Department of Food Science and Nutrition, Zhejiang University, Hangzhou, 310029 China.
authors.forename: Tao
authors.initials: T
authors.lastname: Huang
authors.forename: Mark L
authors.initials: ML
authors.lastname: Wahlqvist
authors.forename: Duo
authors.initials: D
authors.lastname: Li
mesh_terms: D003542:Cystathionine gamma-Lyase / Q000235:genetics*; D004281:Docosahexaenoic Acids / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects*; D015118:Eicosapentaenoic Acid / Q000494:pharmacology; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D056945:Hep G2 Cells; D006710:Homocysteine / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000201:enzymology; D008716:Methionine Adenosyltransferase / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D015854:Up-Regulation / Q000187:drug effects; D017962:alpha-Linolenic Acid / Q000494:pharmacology
chemical_list: D015525:Fatty Acids, Omega-3; D012333:RNA, Messenger; D006710:Homocysteine; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D008716:Methionine Adenosyltransferase; D003542:Cystathionine gamma-Lyase