Does Short-Term Dietary Omega-3 Fatty Acid Supplementation Influence Brain Hippocampus Gene Expression of Zinc Transporter-3?

Nur Sopian,Nurul' Shafie,Mohd Noor,Goh Meng,Hafandi Ahmad,Mohamed Rajion,Mehdi Ebrahimi,Mokrish Ajat

doi:10.3390/ijms160715800

Nur Sopian, Nurul' Shafie + Show 6 more

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https://doi.org/10.3390/ijms160715800

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Abstract

Dietary omega-3 fatty acids have been recognized to improve brain cognitive function. Deficiency leads to dysfunctional zinc metabolism associated with learning and memory impairment. The objective of this study is to explore the effect of short-term dietary omega-3 fatty acids on hippocampus gene expression at the molecular level in relation to spatial recognition memory in mice. A total of 24 male BALB/c mice were randomly divided into four groups and fed a standard pellet as a control group (CTL, n = 6), standard pellet added with 10% (w/w) fish oil (FO, n = 6), 10% (w/w) soybean oil (SO, n = 6) and 10% (w/w) butter (BT, n = 6). After 3 weeks on the treatment diets, spatial-recognition memory was tested on a Y-maze. The hippocampus gene expression was determined using a real-time PCR. The results showed that 3 weeks of dietary omega-3 fatty acid supplementation improved cognitive performance along with the up-regulation of α-synuclein, calmodulin and transthyretin genes expression. In addition, dietary omega-3 fatty acid deficiency increased the level of ZnT3 gene and subsequently reduced cognitive performance in mice. These results indicate that the increased the ZnT3 levels caused by the deficiency of omega-3 fatty acids produced an abnormal zinc metabolism that in turn impaired the brain cognitive performance in mice.

Highlights

Dietary omega-3 fatty acids have important roles in the regulation of brain gene expression associated with brain cognitive function [1,2]
The fish oil (FO) mice spent more time (p < 0.05) in the novel arm compared with the BT and control group (CTL) mice
Polyunsaturated fatty acids can directly interact with transcription factors, like peroxisome proliferator-activated receptors (PPAR) that directly modulate the expression of target genes [18]

Summary

Introduction

Dietary omega-3 fatty acids have important roles in the regulation of brain gene expression associated with brain cognitive function [1,2]. The findings show that the expression of brain genes can be regulated by polyunsaturated fatty acid (PUFA) supplementation, using cDNA microarray analysis and real-time quantitative RT-QPCR. Transthyretin gene participating in signal transduction processes were overexpressed in rat brains receiving a docosahexaenoic acid (DHA) enriched diet for one month [5]. Gene coding for α- and γ-synuclein were overexpressed in response to the diets rich in omega-3 fatty acids for 9 weeks [6]. The DHA enriched diet for 2 weeks in rats increased hippocampal expression of molecules involved in brain-derived neurotrophic factor (BDNF) signaling such as calmodulin kinase II and activated Akt [8]

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