Docosapentaenoic acid (22:5n-3) down-regulates the expression of genes involved in fat synthesis in liver cells

Gunveen Kaur, Andrew J. Sinclair, David Cameron-Smith, Daniel P. Barr, Juan C. Molero-Navajas, Nicky Konstantopoulos

Research output: Contribution to journalArticleResearchpeer-review

37 Citations (Scopus)

Abstract

Previous studies have shown that Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) exhibit triacylglycerol (TAG) lowering effect in vitro and in vivo by down-regulating the Sterol Regulating Element Binding Protein (SREBP-1c) and reducing the expression levels of lipogenic genes. However, there is no evidence on the effect of Docosapentaenoic Acid (DPA) on SREBP-1c expression levels. DPA is a long chain n-3 fatty acid present in our diet through fish, red meat and milk of ruminant animals. Therefore, this study aimed to elucidate the effect of DPA on liver fatty acid synthesis in an in vitro model using rat liver cells. Our results suggested that DPA incubation (50 μM) for 48. h (like EPA and DHA) caused a significant decrease in the mRNA expression levels of SREBP-1c, 3-Hydroxy-3-Methyl-Glutaryl-Coenzyme A reductase (HMG-CoA reductase), Acetyl Coenzyme A Carboxylase (ACC-1) and Fatty Acid Synthase (FASn) compared with Oleic Acid (OA) and also a decrease in the protein levels of SREBP-1 and ACC-1. A time-course fatty acid analysis showed that DPA and EPA are interconvertable in the cells; however, after 8. h of incubation with DPA, the cell phospholipids contained mainly DPA. The gene expression profiling of the lipogenic genes repeated at 8. h confirmed that the inhibitory effect of DPA on mRNA expression levels of the lipogenic genes was most likely due to DPA itself and not due to its conversion into EPA.

Original languageEnglish
Pages (from-to)155-161
Number of pages7
JournalProstaglandins Leukotrienes and Essential Fatty Acids
Volume85
Issue number3-4
DOIs
Publication statusPublished - 1 Sep 2011
Externally publishedYes

Keywords

  • Docosahexaenoic acid (DHA)
  • Docosapentaenoic acid (DPA)
  • Eicosapentaenoic acid (EPA)
  • Fatty acid synthesis
  • Lipogenic genes
  • N-3 Polyunsaturated fatty acids (PUFA)

Cite this