Chronic exposure to chlorpyrifos triggered body weight increase and memory impairment depending on human apoE polymorphisms in a targeted replacement mouse model.
Despite restrictions on their use, humans are still constantly exposed to organophosphates (OPs). A huge number of studies have ratified the neurotoxic effects of chlorpyrifos (CPF) and suggested its association with neurodegenerative diseases, but data are still scarce. Human apolipoprotein E (apoE) plays an important role in lipid transport and distribution. In humans, the apoE4 isoform has been linked to an increased risk of Alzheimer's disease (AD). ApoE3 is the most prevalent isoform worldwide, and has been often established as the healthful one. The current study, performed in targeted replacement (TR) adult male mice, aimed to inquire whether genetic variations of the human apoE respond differently to a chronic dietary challenge with CPF. At four/five months of age, mice carrying apoE2, apoE3 or apoE4 were pair-fed a diet supplemented with CPF at 0 or 2mg/kg body weight/day for 13weeks. Cholinergic signs were monitored daily and body weight changes weekly. In the last week of treatment, learning and memory were assessed in a Barnes maze task. Dietary CPF challenge increased body weight only in apoE3 mice. Differences in the acquisition and retention of the Barnes maze were attributed to apoE genetic differences. Our results showed that apoE4 mice performed worse than apoE2 and apoE3 carriers in the acquisition period of the spatial task, and that apoE2 mice had poorer retention than the other two genotypes. On the other hand, CPF increased the search velocity of apoE2 subjects during the acquisition period. Retention was impaired only in CPF-exposed apoE3 mice. These results underline that gene×environment interactions need to be taken into account in epidemiological studies. Given that apoE3, the most common polymorphism in humans, has proved to be the most sensitive to CPF, the potential implications for human health merit serious thought.
Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, Tarragona, Spain; Department of Psychology and Research Center for Behavioral Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain; Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Reus, Spain.
Fiona
F
Peris-Sampedro
Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, Tarragona, Spain; Department of Psychology and Research Center for Behavioral Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain; Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Reus, Spain.
Pia
P
Basaure
Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, Tarragona, Spain; Department of Psychology and Research Center for Behavioral Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain; Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Reus, Spain.
Ingrid
I
Reverte
Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, Tarragona, Spain; Department of Biochemistry and Biotechnology, Universitat Rovira i Virgili, Tarragona, Spain.
Maria
M
Cabré
Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Reus, Spain.
José L
JL
Domingo
Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, Tarragona, Spain; Department of Psychology and Research Center for Behavioral Assessment (CRAMC), Universitat Rovira i Virgili, Tarragona, Spain; Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Reus, Spain. Electronic address: mariateresa.colomina@urv.cat.
Maria Teresa
MT
Colomina
D000704:Analysis of Variance; D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics*; D001834:Body Water / Q000187:drug effects*; D004390:Chlorpyrifos / Q000633:toxicity*; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D002802:Cholinesterases / Q000097:blood; D004195:Disease Models, Animal; D004435:Eating / Q000187:drug effects; D005838:Genotype; D006801:Humans; D008124:Locomotion / Q000187:drug effects / Q000235:genetics; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced* / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012153:Retention, Psychology / Q000187:drug effects
D001057:Apolipoproteins E; D002800:Cholinesterase Inhibitors; D002802:Cholinesterases; D004390:Chlorpyrifos
Apolipoprotein E; Chlorpyrifos; Learning; Mice; Obesity; Pesticides