PLoS ONE (Jan 2012)

HERVs expression in Autism Spectrum Disorders.

  • Emanuela Balestrieri,
  • Carla Arpino,
  • Claudia Matteucci,
  • Roberta Sorrentino,
  • Francesca Pica,
  • Riccardo Alessandrelli,
  • Antonella Coniglio,
  • Paolo Curatolo,
  • Giovanni Rezza,
  • Fabio Macciardi,
  • Enrico Garaci,
  • Simona Gaudi,
  • Paola Sinibaldi-Vallebona

DOI
https://doi.org/10.1371/journal.pone.0048831
Journal volume & issue
Vol. 7, no. 11
p. e48831

Abstract

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BackgroundAutistic Spectrum Disorder (ASD) is a heterogeneous neurodevelopmental disorder, resulting from complex interactions among genetic, genomic and environmental factors. Here we have studied the expression of Human Endogenous Retroviruses (HERVs), non-coding DNA elements with potential regulatory functions, and have tested their possible implication in autism.MethodsThe presence of retroviral mRNAs from four HERV families (E, H, K and W), widely implicated in complex diseases, was evaluated in peripheral blood mononuclear cells (PBMCs) from ASD patients and healthy controls (HCs) by qualitative RT-PCR. We also analyzed the expression of the env sequence from HERV-H, HERV-W and HERV-K families in PBMCs at the time of sampling and after stimulation in culture, in both ASD and HC groups, by quantitative Real-time PCR. Differences between groups were evaluated using statistical methods.ResultsThe percentage of HERV-H and HERV-W positive samples was higher among ASD patients compared to HCs, while HERV-K was similarly represented and HERV-E virtually absent in both groups. The quantitative evaluation shows that HERV-H and HERV-W are differentially expressed in the two groups, with HERV-H being more abundantly expressed and, conversely, HERV-W, having lower abundance, in PBMCs from ASDs compared to healthy controls. PMBCs from ASDs also showed an increased potential to up-regulate HERV-H expression upon stimulation in culture, unlike HCs. Furthermore we report a negative correlation between expression levels of HERV-H and age among ASD patients and a statistically significant higher expression in ASD patients with Severe score in Communication and Motor Psychoeducational Profile-3.ConclusionsSpecific HERV families have a distinctive expression profile in ASD patients compared to HCs. We propose that HERV-H expression be explored in larger samples of individuals with autism spectrum in order to determine its utility as a novel biological trait of this complex disorder.