Laura Bordoni

Intergenerational Effect of Early Life Exposure to Permethrin: Changes in Global DNA Methylation and in Nurr1 Gene Expression

Environmental exposure to pesticides during the early stages of development represents an important risk factor for the onset of neurodegenerative diseases in adult age. Neonatal exposure to Permethrin (PERM), a member of the family of synthetic pyrethroids, can induce a Parkinson-like disease and cause some alterations in striatum of rats, involving both genetic and epigenetic pathways. Through gene expression analysis and global DNA methylation assessment in both PERM-treated parents and their untreated offspring, we investigated on the prospective intergenerational effect of this pesticide. Thirty-three percent of progeny presents the same Nurr1 alteration as rats exposed to permethrin in early life. A decrease in global genome-wide DNA methylation was measured in mothers exposed in early life to permethrin as well as in their offspring, whereas untreated rats have a hypermethylated genomic DNA. Further studies are however needed to elucidate the molecular mechanisms, but, despite this, an intergenerational PERM-induced damage on progenies has been identified for the first time.

In vivo and in silico studies to identify mechanisms associated with Nurr1 modulation following early life exposure to permethrin in rats.

The present work was designed to study the mechanisms associated with Nurr1 modulation following early life permethrin (PERM) treatment during rats life span. Here we demonstrate that PERM exposure in rats, at a dose close to No Observed Adverse Effect Level (NOAEL) for 15days during neonatal brain development leads to its accumulation long after exposure. In striatum from adolescent rats we detected an increase in DNA methyltransferases (DNMTs) such as DNMT1, DNMT3a, Tyrosine hydroxylase, monomeric and aggregated α-synuclein protein levels. Adult rats showed enhanced DNMT3b and α-synuclein aggregation compared to the control group, while with aging a significant decrease in all biomarkers studied was observed. No changes in Nurr1 promoter methylation in adolescent, adult and old rats were found. In silico studies showed clear evidence of a strong binding interaction between PERM and its metabolite 3-phenoxybenzoic acid with the nuclear orphan receptor Nurr1. These findings suggest that an additional interference with the dopaminergic neuron pathway could occur in situ during PERM accumulation in brain. Therefore, Nurr1 modulation in early life PERM-treated rats, depends on age-related adaptive responses in animals.

Obesity‐related genetic polymorphisms and adiposity indices in a young Italian population

Pediatric obesity develops when a complex biological predisposition collides with an obesogenic environment. To further elucidate the role of genetics in obesity onset, we performed a candidate‐gene association study in a young and sportive Italian population by testing the association of functional polymorphisms in ACE (rs4646994), FTO (rs9939609), MC4R (rs17782313) and PPARG (rs1801282) genes with body mass index (BMI) and waist‐to‐height ratio (WHtR). We also tested the combinations of identified risk genotypes and epistatic interactions among them to determine the existence of cumulative effects in predicting the predisposition to gain weight. Our results confirm a significant direct influence of MC4R rs17782313 and PPARG rs1801282 on body composition, that is, minor allele homozygotes showed significantly higher BMI (rs17782313, β = 1.258, P = 0.031; rs1801282, β = 6.689, P = 1.2 × 10−4) and WHtR (rs17782313, β = 0.021, P = 0.005; rs1801282, β = 0.069, P = 0.003) values. Moreover, by leveraging multifactor dimensionality reduction and general linear model (GLM) approaches we identified an epistatic interaction between ACE and MC4R, where heterozygosity at ACE rs4646994 seems to protect from the unfavorable predisposition to gain weight given by C/C genotype at MC4R rs17782313 (GLM, P = 0.004). In conclusion, to clarify the role of genetics in multifactorial diseases remains a difficult goal, even for the most investigated polymorphisms and in controlled populations. Further studies on epistasis and gene–gene interaction will help to elucidate this complex scenario.

Permethrin pesticide induces NURR1 up-regulation in dopaminergic cell line: Is the pro-oxidant effect involved in toxicant-neuronal damage?

The mechanisms associated to the development of neurodegeneration due to pesticide exposure are not clear yet. In this study we evaluated how permethrin pesticide (PERM) can influence the Nurr1 gene and protein expression, and if a pro-oxidant activity of the pesticide contributes to up-regulation of Nurr1 in a dopaminergic cell line. Incubation of PC12 cells with 1μM PERM for 72h, leads to over expression of Nurr1 gene. This effect occurs with both corn oil and extra virgin olive oil (EVO) used to solubilize the toxicant. In order to investigate if the Nurr1 up-regulation induced by PERM, was associated to the pro-oxidant activity of the pesticide, anti-oxidants as glutathione (GSH), tocotrienols (TOC) and Electrolyzed Reduced Water (ERW) were tested. RT-PCR of Nurr1 showed that its up-regulation was significantly reduced in the presence of antioxidants, especially by addition of ERW. Western-blot analysis reveals that ERW was able to counterbalance the up-regulation of Nurr1 protein induced by permethrin exposure.

Angiotensin-Converting Enzyme Ins/Del Polymorphism and Body Composition: The Intermediary Role of Hydration Status.

Background: The well-known insertion/deletion polymorphism (rs4646994) of the angiotensin-converting enzyme (ACE) gene has been previously associated with obesity, blood flow, muscular strength, and ACE enzyme activity. Despite the relevant role of ACE in homeostasis, few data are currently available on the relationship between rs4646994 and hydration status. Thus, we tested the association between the ACE Ins/Del polymorphism, body composition, and hydration status in a young Italian population. Methods: A total of 306 healthy children and adolescents who regularly practice sports were recruited. Anthropometric, bioimpedentiometric parameters, and urine samples were collected, while ACE rs4646994 genotyping was performed on DNA from buccal swabs. General linear models were used for association testing. Results: The ACE Ins/Del polymorphism was associated with body composition. Ins/Ins individuals had higher phase angle (PhA) and body cellular mass index (BCMI) values. A significant influence of the ACE rs4646994 according to hydration status on body composition was also identified. In particular, Ins/Ins individuals displayed higher PhA and BCMI values only if norm-hydrated, while they showed values similar to Del carriers if dehydrated. Conclusion: Our results confirm the relationship between the ACE Ins/Del polymorphism and body composition and suggest a role for hydration status in modulating this relationship. These interesting preliminary results warrant further investigation to disentangle the genetic role of ACE on hydration homeostasis.