Exploring miRNAs' Based Modeling Approach for Predicting PIRA in Multiple Sclerosis: A Comprehensive Analysis.

The current hypothesis on the pathophysiology of multiple sclerosis (MS) suggests the involvement of both inflammatory and neurodegenerative mechanisms. Disease Modifying Therapies (DMTs) effectively decrease relapse rates, thus reducing relapse-associated disability in people with MS. In some patients, disability progression, however, is not solely linked to new lesions and clinical relapses but can manifest independently. Progression Independent of Relapse Activity (PIRA) significantly contributes to long-term disability, stressing the urge to unveil biomarkers to forecast disease progression. Twenty-five adult patients with relapsing-remitting multiple sclerosis (RRMS) were enrolled in a cohort study, according to the latest McDonald criteria, and tested before and after high-efficacy Disease Modifying Therapies (DMTs) (6-24 months). Through Agilent microarrays, we analyzed miRNA profiles from peripheral blood mononuclear cells. Multivariate logistic and linear models with interactions were generated. Robustness was assessed by randomization tests in R. A subset of miRNAs, correlated with PIRA, and the Expanded Disability Status Scale (EDSS), was selected. To refine the patient stratification connected to the disease trajectory, we computed a robust logistic classification model derived from baseline miRNA expression to predict PIRA status (AUC = 0.971). We built an optimal multilinear model by selecting four other miRNA predictors to describe EDSS changes compared to baseline. Multivariate modeling offers a promising avenue to uncover potential biomarkers essential for accurate prediction of disability progression in early MS stages. These models can provide valuable insights into developing personalized and effective treatment strategies.

Disordered eating in early childhood: DRD4 and DAT1 gene polymorphisms and quality of mother-child interaction.

PURPOSE: Eating disturbances are complex heritable conditions that can be influenced by both genetic and environmental factors but are poorly studied in early development. The aim of this research was to investigate the association of genetic polymorphisms within dopaminergic pathways with early feeding problems. METHODS: We analyzed the presence of VNTR polymorphisms of DRD4 (rs1805186) and DAT1 (rs28363170) in overeating (N = 45), undereating (N = 48) and control (N = 44) young children. We also assessed presence of externalizing, internalizing and dysregulation symptoms by the Child Behavior Checklist and quality of mother-child interactions during feeding by the Italian adaptation of the Scale for the Assessment of Feeding Interaction, respectively. RESULTS: Both polymorphisms were associated with children's eating behavior, psychological symptoms and quality of interaction with their mothers, suggesting that: (a) the DRD4 4-repeat allele behaves as a protective factor, the 2-repeats and 7-repeats alleles as risk factors, for undereating behavior, the general quality of mother-child interaction and internalizing, externalizing and dysregulated symptoms; and (b) the DAT1 9-repeats allele behaves as a protective factor, the 10-repeats allele as a risk factor, for overeating behavior, the general quality of mother-child interaction, internalizing, externalizing and dysregulated symptoms. Finally, a gene x gene interaction is suggested between the DAT1 9-repeat or 10-repeat allele and the DRD4 4-repeat allele. CONCLUSIONS: Our results suggest a role for DRD4 and DAT1 in an early susceptibility to eating disturbances. LEVEL OF EVIDENCE III: Evidence obtained from well-designed case-control analytic study.

DNA methylation of the 5'-UTR DAT 1 gene in Parkinson's disease patients.

OBJECTIVES: The involvement of epigenetics mechanisms in the transcriptional regulation of key genes has been investigated in the initiation and progression of neurodegenerative disorders, including Parkinson's disease (PD). Among others, we, here, focused the attention on the dopamine transporter (DAT) gene playing a critical role in maintaining the integrity of dopaminergic neurons. MATERIALS AND METHODS: We performed bisulfite pyrosequencing to examine DNA methylation levels of six CpG sites in the 5'-UTR of DAT1 gene in human peripheral blood mononuclear cells (PBMCs) obtained from 101 sporadic PD patients and 59 healthy controls. RESULTS: We selectively report for CpG5 an increase in DNA methylation levels in PD subjects respect to controls, that almost reaches statistical significance (30.06 ± 12.4 vs 26.58 ± 7.6, P = .052). Of interest, a significantly higher methylation at specific CpG sites (ANOVA: P = .029) was observed in PD subjects with advanced stage of illness. Namely, a multivariate regression analysis showed that a higher methylation level at specific CpG sites in the group of PD patients was associated with increased methylation at CpG2, CpG3, and with H&Y stage but not with age and gender. This regression model explains the 38% of the variance of methylation at CpG5. CONCLUSION: Our results do seem to suggest that the methylation level of CpG5 is different between PD patients and controls. Moreover, this methylation level for CpG5 may be associated also with the stage of disease.

Potential for diagnosis versus therapy monitoring of attention deficit hyperactivity disorder: a new epigenetic biomarker interacting with both genotype and auto-immunity.

In view of the need for easily accessible biomarkers, we evaluated in ADHD children the epigenetic status of the 5'-untranslated region (UTR) in the SLC6A3 gene, coding for human dopamine transporter (DAT). We analysed buccal swabs and sera from 30 children who met DSM-IV-TR criteria for ADHD, assigned to treatment according to severity. Methylation levels at six-selected CpG sites (among which, a CGGCGGCGG and a CGCG motif), alone or in combination with serum titers in auto-antibodies against dopamine transporter (DAT aAbs), were analysed for correlation with CGAS scores (by clinicians) and Conners' scales (by parents), collected at recruitment and after 6 weeks. In addition, we characterized the DAT genotype, i.e., the variable number tandem repeat (VNTR) polymorphisms at the 3'-UTR of the gene. DAT methylation levels were greatly reduced in ADHD patients compared to control, healthy children. Within patients carrying at least one DAT 9 allele (DAT 9/x), methylation at positions CpG2 and/or CpG6 correlated with recovery, as evident from delta-CGAS scores as well as delta Conners' scales ('inattentive' and 'hyperactive' subscales). Moreover, hypermethylation at CpG1 position denoted severity, specifically for those patients carrying a DAT 10/10 genotype. Intriguingly, high serum DAT-aAbs titers appeared to corroborate indications from high CpG1 versus high CpG2/CpG6 levels, likewise denoting severity versus recovery in DAT 10/10 versus 9/x patients, respectively. These profiles suggest that DAT 5'UTR epigenetics plus serum aAbs can serve as suitable biomarkers, to confirm ADHD diagnosis and/or to predict the efficacy of treatment.

Paternal alcohol exposure in mice alters brain NGF and BDNF and increases ethanol-elicited preference in male offspring.

Ethanol (EtOH) exposure during pregnancy induces cognitive and physiological deficits in the offspring. However, the role of paternal alcohol exposure (PAE) on offspring EtOH sensitivity and neurotrophins has not received much attention. The present study examined whether PAE may disrupt nerve growth factor (NGF) and/or brain-derived neurotrophic factor (BDNF) and affect EtOH preference/rewarding properties in the male offspring. CD1 sire mice were chronically addicted for EtOH or administered with sucrose. Their male offsprings when adult were assessed for EtOH preference by a conditioned place preference paradigm. NGF and BDNF, their receptors (p75(NTR) , TrkA and TrkB), dopamine active transporter (DAT), dopamine receptors D1 and D2, pro-NGF and pro-BDNF were also evaluated in brain areas. PAE affected NGF levels in frontal cortex, striatum, olfactory lobes, hippocampus and hypothalamus. BDNF alterations in frontal cortex, striatum and olfactory lobes were found. PAE induced a higher susceptibility to the EtOH rewarding effects mostly evident at the lower concentration (0.5 g/kg) that was ineffective in non-PAE offsprings. Moreover, higher ethanol concentrations (1.5 g/kg) produced an aversive response in PAE animals and a significant preference in non-PAE offspring. PAE affected also TrkA in the hippocampus and p75(NTR) in the frontal cortex. DAT was affected in the olfactory lobes in PAE animals treated with 0.5 g/kg of ethanol while no differences were found on D1/D2 receptors and for pro-NGF or pro-BDNF. In conclusion, this study shows that: PAE affects NGF and BDNF expression in the mouse brain; PAE may induce ethanol intake preference in the male offspring.

Stimulation of 5-HT7 receptor during adolescence determines its persistent upregulation in adult rat forebrain areas.

Brain serotonin 7 (5-HT7) receptors play an important functional role in learning and memory, in regulation of mood and motivation, and for circadian rhythms. Recently, we have studied the modulatory effects of a developmental exposure (under subchronic regimen) in rats with LP-211, a brain-penetrant and selective 5-HT7 receptor agonist. We aimed at further deciphering long-term sequelae into adulthood. LP-211 (0.250 mg/kg i.p., once/day) was administered for 5 days during the adolescent phase (postnatal days 43-45 to 47-49). When adult (postnatal days >70), forebrain areas were obtained for ex vivo immunohistochemistry, whose results prompted us to reconsider the brain connectivity maps presented in our previous study (Canese et al., Psycho-Pharmacol 2015;232:75-89.) Significant elevation in levels of 5-HT7 receptors were evidenced due to adolescent LP-211 exposure, in dorsal striatum (which also shows an increase of dopaminergic D2 auto-receptors) and-unexpectedly-in piriform cortex, with no changes in ventral striatum. We observed that functional connectivity from a seed on the right hippocampus was more extended than reported, also including the piriform cortex. As a whole, the cortical loop rearranged by adolescent LP-211 exposure consisted in a hippocampus receiving connections from piriform cortex and dorsal striatum, the latter both directly and through functional control over the 'extended amygdala'. Such results represent a starting point to explore neurophysiology of 5-HT7 receptors. Further investigation is warranted to develop therapies for sleep disorders, for impaired emotional and motivational regulation, for attentive and executive deficit. The 5-HT7 agonist LP-211 (0.250 mg/kg i.p., once/day) was administered for 5 days during adolescence (postnatal days 43-45 to 47-49) in rats. When adult (postnatal days >70), a significant elevation in levels of 5-HT7 receptors were evidenced in dorsal striatum and-unexpectedly-in piriform cortex.

Alcohol dependence and serotonin transporter functional polymorphisms 5-HTTLPR and rs25531 in an Italian population.

AIMS: The role of the serotonin transporter gene (SLC6A4) in alcohol dependence (AD) is still unclear. In this paper, we have evaluated the association of the SLC6A4 gene polymorphisms 5-HTTLPR and rs25531 in AD and assessed the polymorphic patterns both in alcoholics and in healthy people of an Italian population. METHODS: Genotyping of the 5-HTTLPR (L/S) and rs25531 (A/G) polymorphisms of the SLC6A4 gene was performed on 403 alcoholics outpatients and 427 blood donors. RESULTS: Comparing AD and control populations and taking into account statistical correction for multiple testing, we found no statistically significant differences for 5-HTTLPR (L/S) and rs25531 polymorphisms in terms of either genotypes or alleles frequencies. By univariate ANOVA, a statistically significant difference was found in the onset of AD: the mean age of onset resulted to be of 25.4 years in males in respect to 28.1 in females. In particular in males, the early AD onset was different, in a statistically significant manner, depending on the presence of at least one S or Lg allele (24.6 years) in respect to La homozygotes (27.5 years) (P = 0.03). CONCLUSIONS: These findings suggest that genetic factors contribute, together with gender and age, to the onset differences in alcohol-dependent phenotypes.

The upstream Variable Number Tandem Repeat polymorphism of the monoamine oxidase type A gene influences trigeminal pain-related evoked responses.

Monoamines have an important role in neural plasticity, a key factor in cortical pain processing that promotes changes in neuronal network connectivity. Monoamine oxidase type A (MAOA) is an enzyme that, due to its modulating role in monoaminergic activity, could play a role in cortical pain processing. The X-linked MAOA gene is characterized by an allelic variant of length, the MAOA upstream Variable Number Tandem Repeat (MAOA-uVNTR) region polymorphism. Two allelic variants of this gene are known, the high-activity MAOA (HAM) and low-activity MAOA (LAM). We investigated the role of MAOA-uVNTR in cortical pain processing in a group of healthy individuals measured by the trigeminal electric pain-related evoked potential (tPREP) elicited by repeated painful stimulation. A group of healthy volunteers was genotyped to detect MAOA-uVNTR polymorphism. Electrical tPREPs were recorded by stimulating the right supraorbital nerve with a concentric electrode. The N2 and P2 component amplitude and latency as well as the N2-P2 inter-peak amplitude were measured. The recording was divided into three blocks, each containing 10 consecutive stimuli and the N2-P2 amplitude was compared between blocks. Of the 67 volunteers, 37 were HAM and 30 were LAM. HAM subjects differed from LAM subjects in terms of amplitude of the grand-averaged and first-block N2-P2 responses (HAM>LAM). The N2-P2 amplitude decreased between the first and third block in HAM subjects but not LAM subjects. The MAOA-uVNTR polymorphism seemed to influence the brain response in a repeated tPREP paradigm and suggested a role of the MAOA as a modulator of neural plasticity related to cortical pain processing.

Clinical subtypes in Parkinson's disease: the impact of MAPT haplotypes.

The H1 haplotype of the MAPT gene influences the risk of PD and has been related to the development of PDD. We evaluated the influence of MAPT haplotypes on the expression of motor features in PD patients. We genotyped, for the MAPT haplotypes H1 and H2, a sample of 181 PD patients with distinct clinical subtypes: tremor dominant and non-tremor dominant (NTD). Our results indicate that the MAPT haplotypes contribute to the expression of motor features of PD. H1 homozygous PD patients are significantly more likely to present a NTD phenotype, a clinical subtype characterized by widespread pathological degeneration, than H2 carriers.

DAT1 5'-Un-Translated-Region Methylation Patterns as Bio-Markers of ADHD Psycho-Pathology: Contribution to Disease Prognosis and to Monitoring of a Successful Therapy.

Epigenetic modifications, such as changes in DNA methylation, have been linked to several diseases in recent years. The purpose of our study was to search for biomarkers that (using non-invasive techniques) could assist the clinician in the prognosis of infant/adolescent psychopathology. We previously showed that changes in methylation of the 5'-UTR in the DAT1/SLC6A3 gene can be used as a biomarker for the prognosis of initial severe ADHD: treatment-resistant severe ADHD children were characterized by methylated CpG 1 in particular, while methylated CpGs 2 and 6 were then found in children who improved after the therapy. Further, we confirmed these outcomes and provided the hypothesis that symptomatology might be influenced by the children's genotype and family environment. In particular, levels of CpG 3 methylation in the heterozygous ADHD children were associated with high paternal own risk or stress. Eventually, we found that the same biomarkers are more broadly useful in the field of internalizing or externalizing symptoms (when a certain vulnerability is already present in the child). In particular, it was seen how inheriting specific 9-repeat or 10-repeat VNTR alleles from the mother or from the father could modify the pattern of methylation at the 5'-UTR of the DAT1 gene. A specific pattern of methylations (with CpG 2 following either CpGs 1 + 3 or CpG 6 at the DAT1 5'-UTR) has been associated, therefore, with the likelihood of an internalizing or externalizing developmental trajectory entailing ADHD-like psycho-pathological characteristics. Since each individual responds differently to a specific treatment, we suggest that these methylation patterns may be used as biomarkers to monitor the outcome and/or predict the success of a given therapy (personalized medicine).

How Can CpG Methylations, and Pair-to-Pair Correlations between the Main (Gene) and the Opposite Strands, Suggest a Bending DNA Loop: Insights into the 5'-UTR of DAT1.

A working hypothesis issues from patterns of methylation in the 5'-UTR of the DAT1 gene. We considered relationships between pairs of CpGs, of which one on the main-gene strand and another on the complementary opposite strand (COS). We elaborated on data from ADHD children: we calculated all possible combinations of probabilities (estimated by multiplying two raw values of methylation) in pairs of CpGs from either strand. We analyzed all correlations between any given pair and all other pairs. For pairs correlating with M6-M6COS, some pairs had cytosines positioning to the reciprocal right (e.g., M3-M2COS and M6-M5COS), other pairs had cytosines positioning to the reciprocal left (e.g., M2-M3COS; M5-M6COS). Significant pair-to-pair correlations emerged between main-strand and COS CpG pairs. Through graphic representations, we hypothesized that DNA folded to looping conformations: the C1GG C2GG C3GG and C5G C6G motifs would become close enough to allow cytosines 1-2-3 to interact with cytosines 5-6 (on both strands). Data further suggest a sliding, with left- and right-ward oscillations of DNA strands. While thorough empirical verification is needed, we hypothesize simultaneous methylation of main-strand and COS DNA ("methylation dynamics") to serve as a promising biomarker.

Methylation Dynamics on 5'-UTR of DAT1 Gene as a Bio-Marker to Recognize Therapy Success in ADHD Children.

Attention-deficit/hyperactivity disorder (ADHD), a neuropsychiatric condition characterized by inattention, hyperactivity, and impulsivity, afflicts 5% of children worldwide. Each ADHD patient presents with individual cognitive and motivational peculiarities. Furthermore, choice of appropriate therapy is still up to clinicians, who express somewhat qualitative advice on whether a child is being successfully cured or not: it would be more appropriate to use an objective biomarker to indicate whether a treatment led to benefits or not. The aim of our work is to search for such clinical biomarkers. We recruited 60 ADHD kids; psychopathological scales were administered at recruitment and after six weeks of therapy. Out of such a cohort of ADHD children, we rigorously extracted two specific subgroups; regardless of the initial severity of their disease, we compared those who obtained the largest improvement (ΔCGAS > 5) vs. those who were still characterized by a severe condition (CGAS < 40). After such a therapy, methylation levels of DNA extracted from buccal swabs were measured in the 5'-UTR of the DAT1 gene. CpGs 3 and 5 displayed, in relation to the other CpGs, a particular symmetrical pattern; for "improving" ADHD children, they were methylated together with CpG 2 and CpG 6; instead, for "severe" ADHD children, they accompanied a methylated CpG 1. These specific patterns of methylation could be used as objective molecular biomarkers of successful cures, establishing if a certain therapy is akin to a given patient (personalized medicine). Present data support the use of post-therapy molecular data obtained with non-invasive techniques.

Cladribine and ocrelizumab induce differential miRNA profiles in peripheral blood mononucleated cells from relapsing-remitting multiple sclerosis patients.

Background and objectives: Multiple sclerosis (MS) is a chronic, progressive neurological disease characterized by early-stage neuroinflammation, neurodegeneration, and demyelination that involves a spectrum of heterogeneous clinical manifestations in terms of disease course and response to therapy. Even though several disease-modifying therapies (DMTs) are available to prevent MS-related brain damage-acting on the peripheral immune system with an indirect effect on MS lesions-individualizing therapy according to disease characteristics and prognostic factors is still an unmet need. Given that deregulated miRNAs have been proposed as diagnostic tools in neurodegenerative/neuroinflammatory diseases such as MS, we aimed to explore miRNA profiles as potential classifiers of the relapsing-remitting MS (RRMS) patients' prospects to gain a more effective DMT choice and achieve a preferential drug response. Methods: A total of 25 adult patients with RRMS were enrolled in a cohort study, according to the latest McDonald criteria before (pre-cladribine, pre-CLA; pre-ocrelizumab, pre-OCRE, time T0) and after high-efficacy DMTs, time T1, 6 months post-CLA (n = 10, 7 F and 3 M, age 39.0 ± 7.5) or post-OCRE (n = 15, 10 F and 5 M, age 40.5 ± 10.4) treatment. A total of 15 age- and sex-matched healthy control subjects (9 F and 6 M, age 36.3 ± 3.0) were also selected. By using Agilent microarrays, we analyzed miRNA profiles from peripheral blood mononuclear cells (PBMC). miRNA-target networks were obtained by miRTargetLink, and Pearson's correlation served to estimate the association between miRNAs and outcome clinical features. Results: First, the miRNA profiles of pre-CLA or pre-OCRE RRMS patients compared to healthy controls identified modulated miRNA patterns (40 and seven miRNAs, respectively). A direct comparison of the two pre-treatment groups at T0 and T1 revealed more pro-inflammatory patterns in the pre-CLA miRNA profiles. Moreover, both DMTs emerged as being capable of reverting some dysregulated miRNAs toward a protective phenotype. Both drug-dependent miRNA profiles and specific miRNAs, such as miR-199a-3p, miR-29b-3p, and miR-151a-3p, emerged as potentially involved in these drug-induced mechanisms. This enabled the selection of miRNAs correlated to clinical features and the related miRNA-mRNA network. Discussion: These data support the hypothesis of specific deregulated miRNAs as putative biomarkers in RRMS patients' stratification and DMT drug response.

Effect of stress on hippocampal nociceptin expression in the rat.

Nociceptin/orphanin FQ (N/OFQ) peptide and its receptor are not only ubiquitously expressed in mammalian brain and spinal cord but are also abundant in limbic structures, particularly in the hippocampus. The widespread distribution of N/OFQ reflects the broad spectrum of its biological actions such as nociception, food intake, spontaneous locomotor activity, and learning and memory processes. Since the hippocampus is involved in the control of adrenocortical activity, its role in stress-related phenomena is well characterized. In male Wistar rats, we first examined the effects of acute restraint stress (120 min) on the brain immunohistochemical localization of N/OFQ. The analysis carried out on sections obtained at the onset of stress revealed enhanced expression of N/OFQ in CA1, CA3, and the dentate gyrus as well as increased plasma corticosterone concentrations. Next, we examined whether endogenous glucocorticoid hormone plays a role in the modulation of hippocampal N/OFQ expression in response to stress. To this end, rats were injected with corticosterone (1 mg/kg) or subjected to restraint stress 1 week after adrenalectomy. Two hours after corticosterone administration, plasma glucocorticoid concentrations were comparable to those observed after restraint stress, while N/OFQ expression had significantly increased in all the hippocampal subfields examined. By contrast, in adrenalectomized rats, stress did not modify protein expression. These results confirm that stress can affect N/OFQ expression and that glucocorticoids may constitute hormonal mediators of this complex interplay.

Cortical response to somatosensory stimulation in medication overuse headache patients is influenced by angiotensin converting enzyme (ACE) I/D genetic polymorphism.

BACKGROUND: Medication overuse headache (MOH) is a disabling health problem. Convincing evidence attributes a pathophysiologic role to central sensitization. By recording somatosensory evoked potentials (SSEPs) in patients with MOH, we observed increased sensitization and deficient habituation to repetitive sensory stimuli consistent with drug overuse. The renin-angiotensin system in the brain seems to play a relevant role in neural plasticity and dependence behavior. We therefore sought differences in SSEP sensitization and habituation in patients with MOH who underwent angiotensin converting enzyme (ACE) I/D polymorphism analysis. METHODS: We recorded median-nerve SSEPs (two blocks of 100 sweeps) in 43 patients with MOH. We measured N20-P25 amplitudes, and assessed sensitization using the first block amplitudes, and habituation using amplitude changes between the two sequential blocks. According to their genotype, subjects were divided into three groups: "D/D", "D/I" and "I/I" carriers. RESULTS: The habituation slope of the two SSEP block amplitudes was significantly increased in the D/D subgroup (n = 16) with respect to that of the I/I subgroup (n = 6), with the D/I subgroup (n = 21) falling in between. In D/D carriers, the habituation slope correlated positively with the duration of the overuse headache, and the first SSEP block amplitudes, a measure of sensitization, increased in strict relationship with the type of overused medication in the MOH patients overall and in the D/D subgroup; this was not so in the D/I and I/I subgroups. CONCLUSION: In patients with MOH, the homozygote D/D ACE polymorphism influences habituation and sensitization to repeated sensory stimuli in strict relationship with medication overuse. We suggest that angiotensin peptides influence neuronal mechanisms of plasticity by interacting with central monoaminergic synaptic transmission.

Monomorphic region of the serotonin transporter promoter gene in New World monkeys.

Genetic variation in the human serotonin system has long been studied because of its functional consequences and links to various neuropsychiatric and behavior-related disorders. Among non-human primates, the common marmosets (Callithrix jacchus) and tufted capuchins monkeys (Cebus apella) are becoming increasingly used as models to study the effects of genes, environments, and their interaction on physiology and complex behavior. In order to investigate the independent functions of and potential interactions between serotonin-related genes, anxiety and neuropsychiatric disorders, we analyzed the presence and variability of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) in marmoset and capuchin monkeys. By PCR and using heterologous primers from the human sequence, we amplified and then sequenced the corresponding 5-HTT region in marmosets and capuchins. The resulting data revealed the presence of a tandem repeat sequence similar to that described in humans, but unlike humans and other Old World primates, no variable length alleles were detected in these New World monkeys, suggesting that if serotonin transporter is involved in modulating behavior in these animals it does so through different molecular mechanisms.

Methylation patterns within 5'-UTR of DAT1 gene as a function of allelic 3'-UTR variants and their maternal or paternal origin: May these affect the psychopathological phenotypes in children? An explorative study.

Psychopathological symptoms such as depression/anxiety vs attention or aggression problems, in children, have been associated to altered expression of the DAT1/SLC6A3 gene. Inheriting specific 9- or 10-repeat VNTR alleles could modify the pattern of methylation in the CpGs islands at the 5'-UTR of the DAT1 gene. Through accurate recruitment at primary schools, we ended up with four subgroups of children: 9/9 and 10/10 homozygous; 9/10 heterozygous born from 9/10 mothers and 10/10 fathers (called heM); 9/10 heterozygous born from 10/10 mothers and 9/10 fathers (called heF). (Epi)genetical changes were found to be in relation to internalizing and externalizing symptoms: compared to other genotypes, our 9/9 children exhibited mainly internalizing symptoms, while 10/10 genotype was previously associated with ADHD severity. We found that 10/10 children bear 5'-UTR motifs showing a CpGs 1-2-3-5 unity with anticorrelated CpG 6, while 9/9 children showed rather a demethylated CpG 1 linked to demethylated CpG 6. We found two different patterns between heMs and heFs: a feature of heM children is in CpGs 1-3 methylated pattern with CpGs 2, 5 and 6 demethylated together, supporting a "split" unitary destiny. Within the heF children, the status for CpGs 3 + 6 remained opposite, yet pattern of (de)methylation was not well defined. The prevailing one between inherited parental alleles may somewhat influence the motif destiny of heterozigous children. Present work aimed to identify novel epigenetic biomarkers, to be exploited as fairly indicators of children's psychopathological vulnerability.

Epigenetic regulation of DAT gene promoter modulates the risk of externalizing and internalizing behaviors on a normative population: An explorative study.

Accumulating research addressed epigenetic modifications and their role on behavioral phenotypes. We recently proposed to study methylation dynamics of two CpG motifs within the 5'-UTR of dopamine transporter (DAT) gene. Starting from a normative population sample of young adults, we selected three sub-groups based on their prevalent symptoms: subjects were assigned to Internalizing, Externalizing and Low-risk sub-groups according to elevated scores in specific phenotypic scales. Using a new approach, we calculated three independent matrixes of cross-correlation between CpG methylation levels, one within each phenotypic sub-group, to determine in which dynamics did the sub-groups differ. We found specific cross-correlation patterns in Externalizing (CpG1, 2 and 3, opposite to the methylation at CpG6) and Internalizing individuals (CpG1 methylation opposite to CpG2, 3 and 6), while Low-risk individuals could follow both trends. The aim of our study was to look for a specific DAT methylation pattern, providing a biomarker that allows early identification of the risk for psycho-pathological deviance.

Associations Among Internet Addiction, Genetic Polymorphisms, Family Functioning, and Psychopathological Risk: Cross-Sectional Exploratory Study.

BACKGROUND: International research has emphasized that youths are at higher risk for the onset of internet addiction (IA), but studies investigating biological, psychological, and social factors associated with this condition are limited. OBJECTIVE: This study aims to investigate the possible association between IA and genetic polymorphisms in monoamine oxidase A (MAO-A), serotonin-transporter (5-HTTPR), dopamine receptor (DRD4), and dopamine transporter (DAT1) genes by considering the role played by the perception of young adults in their family functioning and their depression, anxiety, and avoidant personality problems. METHODS: In a sample of 104 male and female young adults aged between 19 and 23 years (mean age 21.87, SD 2.29 years) recruited from universities in the central southern part of Italy, we addressed the presence of IA using the Young criteria of the IA test. Moreover, the perception of young adults of their family functioning and their psychopathological symptoms were assessed through the Family Assessment Device (FAD) and the Adult Self-Report, respectively. RESULTS: We found no significant association between IA and any genetic polymorphisms, neither among males or females. Young adults with IA reported significantly higher scores in the subscale of FAD affective responsiveness (AR; P=.01) and in depressive problems (P=.02), anxiety problems (P=.009), and avoidant personality problems (P=.003) than those in the control group. Results of mediation analyses showed a mediation role played by depressive symptoms (B=0.99; 95% CI 0.22 to 1.97) and avoidant personality problems (B=1.09; 95% CI 0.32 to 2.05) of young adults on the relationship between the FAD, AR, and IA. Finally, this relationship was moderated by the genotype of the 5-HTTLPR (P<.001), DAT1 (P<.001), and MAO-A (P<.001) genes in young adults. CONCLUSIONS: This exploratory study supports the recent evidence on the mutual relationship among biological, individual, and social risk factors associated with IA in young adulthood. Our findings may have important clinical implications for the development of prevention and treatment programs.