A Systematic Review of LINE-1 Methylation Profile in Psychiatric Disorders

Abstract

Introduction: Long Interspersed Nuclear Elements (LINE) are endogenous retrotransposable elements. A few studies have linked the methylation pattern of LINE-1 to different mental disorders (e.g. post-traumatic stress disorder [PTSD], autism spectrum disorder [ASD], panic disorder [PD]). We sought to unify the existing knowledge in the field and provide a better understanding of the association between mental disorders and LINE-1 methylation. Methods: A systematic review was executed with 12 eligible articles according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results: For psychotic disorders, PTSD, ASD and PD, lower LINE-1 methylation levels were detected, whereas for mood disorders the findings are controversial. The studies were conducted with subjects aged 18–80 years. Peripheral blood samples were utilized in 7/12 articles. Discussion/Conclusion: Although most studies have shown that LINE-1 hypomethylation was associated with mental disorders, there still were some divergences (i.e. hypermethylation associated with mental disorders). These studies suggest that LINE-1 methylation may be an important factor related to the development of mental disorders and highlight the need to better comprehend the biological mechanisms underlying the role of LINE-1 in mental disorders pathophysiology.

CG-rich trinucleotide two-repeats may be the long-sought recombination hotspot loci shared across primates and mouse

“…The generated cDNAs can be randomly integrated into the host genome (Fu et al, 2023). DNA methylation is induced at these regions to inactivate TEs (Alves et al, 2023). Our exemplary models can explain the entangled mechanisms of piRNAs, LINEs, and SINEs.…”