Low ω-6/ω-3 polyunsaturated fatty acid ratios reduce hepatic C-reactive protein expression in apolipoprotein E–null mice

Abstract 

Objective

Expression characteristics of C-reactive protein (CRP) for the ω-6/ω-3 polyunsaturated fatty acid (PUFA) ratios have not been evaluated in the well-qualified experimental atherosclerotic mouse model. This work focused on characteristics of CRP expression in the liver of apolipoprotein E–null (apoE^−/−) mice influenced by ω-6/ω-3 PUFA ratios.

Methods

Varying ratios of ω-6/ω-3 PUFAs (group 1, 1.28; group 2, 5.03; group 3, 9.98; and group 4, 68.26, respectively) on hepatic and aortic CRP expressions were assessed in male apoE^−/− mice fed a diet containing 5% (w/w) experimental fat for 6 wk. Hepatic peroxisome proliferator-activated receptor-γ mRNA abundance, hepatic interleukin (IL)-6 protein level, atherosclerotic lesions, and serum cytokines including IL-1β, IL-6, and tumor necrosis factor-α were examined.

Results

As the dietary ratio of ω-6/ω-3 fatty acids ascended, so did the expression of hepatic and aortic CRP and hepatic IL-6 protein. However, peroxisome proliferator-activated receptor-γ mRNA level had a tendency to decrease. Serum IL-1β, IL-6, and tumor necrosis factor-α levels did not show a statistical difference among the mice fed the four ratios of the ω-6/ω-3 PUFA diet. The group 4 mice developed a significant increase in atherosclerotic lesions compared with the other groups.

Conclusion

The results indicated that low ratios of ω-6/ω-3 PUFAs (1.28–9.98) downregulated the hepatic and aortic CRP expressions and reduced aortic en face lesions in apoE^−/− mice compared with the high ratio of the ω-6/ω-3 PUFA diet.

Keywords: Apolipoprotein E–null mice, Atherosclerosis, C-reactive protein, Cytokine, Gene expression, Polyunsaturated fatty acid