Currently, genome editing technologies, such as clustered regularly interspaced short palindromic repeats (CRISPR/Cas9), are predominantly used to model genetic diseases. This genome editing system can correct point or frameshift mutations in risk genes. Here, we analyze and discuss the advantages of genome editing, its current applications, and the feasibility of the CRISPR/Cas9 system in research on psychiatric disorders. These disorders produce cognitive and behavioral alterations and their etiology is associated with polygenetic and environmental factors. CRISPR/Cas9 may reveal the biological mechanisms of psychiatric disorders at a basic research level, translating a suitable clinical approach for use in the diagnosis and treatment of psychiatric disorders. Genetic diagnosis and treatment for these disorders have not yet been fully established in psychiatry due to the limited understanding of their heterogeneity and polygenicity. We discuss the challenges and ethical issues in using CRISPR/Cas9 as a tool for diagnosis or gene therapy.

Objective: Individuals with schizophrenia and substance use disorders have a poor prognosis and increased psychiatric symptoms. The present study aimed to explore the association of 106 genes in individuals with schizophrenia and comorbid substance use through a next-generation sequencing (NGS) analysis and different in silico algorithms. Methods: We included 105 individuals diagnosed with schizophrenia and a family history of schizophrenia, of whom 49 (46.67%) presented comorbid substance use. Using NGS, we sequenced 106 genes previously associated with schizophrenia. Logistic regression models were used to assess differences in allele frequencies, and a generalized gene-set analysis was performed at the gene level. Functional annotations were performed using different algorithms and databases. Results: We identified a total of 3,109 variants, of which 25 were associated with schizophrenia and comorbid substance use and were located in regulatory and coding regions. We found low-frequency variants in COMT p.Ala72Ser, independently of p.Val158Met, that were associated with substance use. The endocannabinoid functional variant FAAH p.Pro129Thr was also associated with substance use. Conclusions: Genetic variants of genes related to dopaminergic and cannabinoid neurotransmitter systems were associated with comorbid substance use in schizophrenia. Nevertheless, more studies with larger sample sizes are needed to confirm our findings.

Abstract Objective: To evaluate the progression by means of nuclear magnetic resonance of the lesion in the schizophrenia model of lesion of the ventral hippocampal nucleus (LVNH). Method: Magnetic resonance imaging (MRI) were performed in male Wistar rats, from 8 days postnatal to 139 days, in animals with LNHV and without lesion (sham). The MRI were carried out on a Variant 7 T equipment. The data were analyzed with the Amira software, for a voxel-based morphometric analysis. Results: We observed the presence of hypersignals with a significant enhancement in the structures analyzed in the group with LVNH, and greater volume in the lateral ventricles, presenting a larger size of the lesion on day PD96 and significantly reducing on day PD139. Conclusions: We found a cell rearrangement during the progression of the lesion, which could be the effect of the activation of immune cells.

Resumen Objetivo: Evaluar mediante resonancia magnética (RM) la progresión de la lesión en el modelo de esquizofrenia de lesión del núcleo del hipocampo ventral (LNHV). Método: Se realizaron RM en ratas Wistar macho, desde los 8 días posnatales hasta los 139 días, en animales con LNHV y sin lesión (sham). Las RM se realizaron con un equipo Variant de 7 T. Los datos se analizaron con el software Amira para un análisis de morfometría basada en vóxels. Resultados: Observamos hiperseñales con un realce significativo en las estructuras analizadas en el grupo con LNHV, y mayor volumen en los ventrículos laterales, presentando un mayor tamaño de la lesión el día PD96 y significativamente reducido en el día PD139. Conclusiones: Encontramos un reacomodo celular durante la progresión de la lesión, lo cual podría ser efecto de la activación de las células inmunitarias.

Abstract Background: Gene expression alterations have been implicated in suicide pathology. However, the study of the regulatory effect of DNA methylation on gene expression in the suicidal brain has been restricted to candidate genes. Objective: The objective of the study was to identify genes whose expression levels are correlated with DNA methylation in the prefrontal cortex of suicides. Methods: Postmortem prefrontal cortex samples from 21 suicides and six non-suicides were collected. Transcriptomic and DNA methylation profiles were evaluated with microarrays; cis correlations between gene expression and CpG methylation were screened. We then analyzed the presence of transcription factor (TF) binding sites (TFBS) at CpG sites correlated with gene expression. Gene expression of TFs involved in neurodevelopmental binding to predicted TFBS was determined in the BrainSpan database. Results: We identified 22 CpG sites whose methylation levels correlated with gene expression in the prefrontal cortex of suicides. Genes annotated to identified CpG sites were involved in neurodevelopment (BBS4, NKX6-2, AXL, CTNND1, and MBP) and polyamine metabolism (polyamine oxidase [PAOX]). Such correlations were not detected in the non-suicide group. Nine TFs (USF1, TBP, SF1, NRF1, RFX1, SP3, PKNOX1, MAZ, and POU3F2) showed differential expression in pre- and post-natal developmental periods, according to BrainSpan database. Conclusions: The integration of different omic technologies provided novel candidates for the investigation of genes whose expression is altered in the suicidal brain and their potential regulatory mechanisms. (REV INVEST CLIN. 2020;72(5):283-92)

Resumen Los trastornos de la conducta alimentaria son un problema de salud pública. La etiología de la enfermedad es desconocida, pero se sugiere que tiene una base psiquiátrica, química y biológica. El objetivo de esta revisión es presentar evidencias de cómo la investigación genómica ha contribuido en el estudio de los trastornos de la conducta alimentaria y muestra la intensa investigación dirigida a conocer los genes que pudieran estar participando en la etiológica de los trastornos de la conducta alimentaria.

Abstract Eating behavior disorders are a public health issue. The etiology of these types of disorders is unknown, and they may have psychiatric, chemical and biological origins. The aim of this review is to present evidence that shows the contribution of genomic research in the study of eating behavior disorders. It also shows the considerable research that has been undertaken to identify the genes that may participate in the etiology of eating behavior disorders.