Apolipoprotein E ε4 allele and malondialdehyde level are independent risk factors for Alzheimer’s disease

Abstract

Background:The ε4 allele of Apolipoprotein E is involved in lipid metabolism. Oxidative stress produces an increase in lipid peroxidation that has been implicated in the pathogenic cascade in Alzheimer’s disease. This study estimated the effect of the ε4 allele, malondialdehyde and lipid levels on the risk for Alzheimer’s disease.Methods:A total of 41 control subjects and 73 patients with Alzheimer’s disease were recruited. The Apolipoprotein E genotype was determined by amplification of exon 4 of the Apolipoprotein E by polymerase chain reaction (PCR); malondialdehyde concentration was determined by high-pressure liquid chromatography, and serum lipids were measured by routine photometric techniques.Results:Malondialdehyde levels were significantly higher in Alzheimer’s disease patients independent of the Apolipoprotein E genotype and ε4 allele. The ε4 allele increases the risk of Alzheimer’s disease by 5.114 times and elevated malondialdehyde levels increase the risk by 9.342.Conclusion:The presence of ε4 allele and elevated malondialdehyde levels are independent risk factors for Alzheimer’s disease. These findings support the hypothesis that lipid peroxidation and ε4 allele contribute to the pathogenic cascade in Alzheimer’s disease by different pathways.

Assessment of Possible Association Between Antioxidant Levels and Apoe Gene Polymorphism in Demented Saudi Population

“…While in case of control group, non-significant difference was reported between females and males group. This observation was similar from previous publications that reported significant differences not only in MDA levels but also in various oxidative stress biomarkers like protein oxidation and DNA oxidation (Schrag et al, 2013;Chang et al, 2014;Iova et al, 2014;López-Riquelme et al, 2016). Demented females had higher levels of malondialdehyde than males that might be due to their higher prevalence of vascular diseases and lipid disorder.…”

“…These findings support the hypothesis that demonstrate the presence of E4 allele and decline antioxidant level with elevated lipid peroxidation are independent risk factors for dementia. and they are contribute to the pathogenic cascade in dementia by different pathways (Ihara et al, 2000;Zito et al, 2013;López-Riquelme et al, 2016). In conclusion, our study indicated that the APOE4 allele and oxidative stress are separated risk factor in the pathogenesis of dementia in the Saudi population.…”

“…While some studies have shown that APOE4 is positively associated with markers of oxidative stress and negatively associated with antioxidant defense markers compared to APOE3 and APOE2 (Chico et al, 2013;Dose et al, 2016). Non significant differences was reported between the APOE isoforms and specific antioxidative properties by Zito et al (2013) and López-Riquelme et al (2016). The overall purpose of this research is to evaluate the possible relationship between APOE genotype and serum level of antioxidant in Saudi patients with dementia of different types.…”

“…On the other hand, the E2 and E3 isoforms possess greater antioxidant activity (Pulido et al, 2005;Baldeiras et al, 2008;Chico et al, 2013;Dose et al, 2016). Other studies showed that APOE genotype and oxidative stress or antioxidant activities are independent risk factors for dementia (Ihara et al, 2000;Zito et al, 2013;López-Riquelme et al, 2016).…”

The genes associated with early-onset Alzheimer’s disease

“…The homozygosity for the APOE ε4 allele, as a major genetic risk factor for LOAD, was shown to be an independent genetic factor that significantly increases the risk of EOAD [ 127 ]. But, unlike mutations in APP , PSEN1 and PSEN2 , the APOE ε4 allele was not considered a significant cause of EOAD and was only a risk factor [ 128 ].…”