Impact of Diesel Exhaust Exposure on the Liver of Mice Fed on omega-3 Polyunsaturated Fatty Acids-Deficient Diet

Food Chem Toxicol. 2018 Jan;111:284-294. doi: 10.1016/j.fct.2017.11.027. Epub 2017 Nov 21.

Abstract

Exposure to diesel exhaust (DE) exacerbates non-alcoholic fatty liver disease, and may systemically affect lipid metabolism. Omega-3 polyunsaturated fatty acids (n-3 PUFA) have anti-inflammatory activity and suppresses hepatic triacylglycerol accumulation, but many daily diets are deficient in this nutrient. Therefore, the effect of DE exposure in mice fed n-3 PUFA-deficient diet was investigated. Mice were fed control chow or n-3 PUFA-deficient diet for 4 weeks, then exposed to clean air or DE by inhalation for further 4 weeks. Liver histology, plasma parameters, and expression of fatty acid synthesis-related genes were evaluated. N-3 PUFA-deficient diet increased hepatic lipid droplets accumulation and expression of genes promoting fatty acid synthesis: Acaca, Acacb, and Scd1. DE further increased the plasma leptin and the expression of fatty acid synthesis-related genes: Acacb, Fasn, and Scd1. N-3 PUFA-deficient diet and DE exposure potentially enhanced hepatic fatty acid synthesis and subsequently accumulation of lipid droplets. The combination of low-dose DE exposure and intake of n-3 PUFA-deficient diet may be an additional risk factor for the incidence of non-alcoholic fatty liver disease. The present study suggests an important mechanism for preventing toxicity of DE on the liver through the incorporation of n-3 PUFAs in the diet.

Keywords: Diesel exhaust; Fatty liver; Lipogenesis; Omega-3 fatty acids; RT-qPCR.

MeSH terms

  • Animal Feed
  • Animals
  • Body Weight
  • Chemical and Drug Induced Liver Injury / pathology*
  • Diet*
  • Energy Intake
  • Fatty Acids, Omega-3 / administration & dosage*
  • Fatty Liver / chemically induced
  • Fatty Liver / pathology
  • Female
  • Gene Expression Regulation / drug effects
  • Liver / drug effects*
  • Mice
  • Mice, Inbred C57BL
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Vehicle Emissions / toxicity*

Substances

  • Fatty Acids, Omega-3
  • RNA, Messenger
  • Vehicle Emissions