Role of gonadal steroids in DNA methylation and demethylation dynamics during neurodevelopment

Many neuropsychiatric disorders originate during development and present sex differences. For example, autism spectrum disorder and schizophrenia are more common in males suggesting a greater vulnerability to develop neurodevelopmental disorders in males. Moreover, most of the sex differences in the brain are organized by a transient exposure to gonadal testosterone (or its metabolite estradiol) in males during a critical perinatal period. The effects of testosterone during this early period are, in many cases, permanent and give rise to a cellular memory for the organizing effects of hormones. Some epigenetic mechanisms are involved in testosterone´s effects on brain masculinization such as DNA methylation, a repressive epigenetic mark that has long been considered a permanent epigenetic mark on the epigenome. However, 5-methylcytosine levels in mammalian brain are dynamic, particularly during development. In recent years, the enzymes and mechanisms involved in the removal of methylation marks towards unmodified cytosines have been identified in the brain. Moreover, the importance of hydroxymethylation as an epigenetic mark by itself and its relevance during brain development is a new field in neuroepigenetics.

DNA methylation has been implicated in a variety of neuropsychiatric diseases. Alterations in methylation pattern could in turn affect the de-methylation process. Thus, the replacement of these epigenetic marks plays an extremely important role and has not yet been evaluated. This project assesses the idea that dynamic changes in methylation during development involve a methylation / demethylation cycle in the promoter region of genes regulated by sex steroids during development. Given that global levels of 5-methylcytosine are lower in some regions of the male brain during development, the methylation / demethylation balance would be inclined towards greater demethylation in males.  Despite our growing understanding of neurodevelopment, there are still gaps in the key sources of vulnerability that put males at risk of developing neurological or neuropsychiatric disorders and, at the same time, protect females. Our project tests the idea that an active turnover of DNA methylation and demethylation marks plays a role in male vulnerability to neurodevelopmental disorders.

Grants: 

International Brain Research Organization (IBRO) Return Home Fellowship 

 

Publications (Last 5 Years)

Complete list available in https://www.ncbi.nlm.nih.gov/myncbi/carla.cisternas.1/bibliography/public/

    1. Cisternas CD, Cabrera Zapata LE, Mir FR, Scerbo MJ, Arevalo MA, Garcia-Segura LM, Cambiasso MJ. Estradiol-dependent axogenesis and Ngn3 expression are determined by XY sex chromosome complement in hypothalamic neurons. Sci Rep. 10(1):8223. 2020. doi: 10.1038/s41598-020-65183-x 
    2. Cisternas CD, Cortes LR, Golynker I, Castillo-Ruiz A, Forger NG. Neonatal Inhibition of DNA Methylation Disrupts Testosterone-Dependent Masculinization of Neurochemical Phenotype. Endocrinology 161(1). 2020. doi: 10.1210/endocr/bqz022. 
    3. Cisternas CD, Cortes LR, Bruggeman E, Yao B, Forger NG. Developmental changes and sex differences in the expression of DNA methylation and demethylation enzymes in hypothalamic regions of the mouse brain. Epigenetics, 15 (1-2), 72-84. 2020. doi: 10.1080/15592294.2019.1649528.  
    4. Jacobs A, Castillo-Ruiz A, Cisternas CD, Forger NG. Microglial depletion causes region-specific effects on developmental neuronal cell death in the mouse brain. Developmental Neurobiology. 2019. doi: 10.1002/dneu.22706. 
    5. Cortes LR*, Cisternas CD*, Forger NG. Does gender leave an epigenetic imprint on the brain? Frontiers in Neuroscience. 13:173. 2019 doi: 10.3389/fnins.2019.00173. Review. *co-primeros autores. 
    6. Cisternas CD, García-Segura LM, Cambiasso MJ. Hormonal and genetic factors interact to control aromatase expression in the developing brain. J Neuroendocrinol 30(2). 2018 doi: 10.1111/jne.12535. Review.
    7. Cambiasso MJ, Cisternas CD, Ruiz-Palmero I, Scerbo MJ, Arevalo MA, Azcoitia I, Garcia-Segura LM. Interaction of sex chromosome complement, gonadal hormones and neuronal steroid synthesis on the sexual differentiation of mammalian neurons. J Neurogenetics. (4):300-306. 2017. doi: 10.1080/01677063.2017.1390572. Review.
    8. Cisternas CD, Cabrera Zapata LE, Arevalo MA, García-Segura LM, Cambiasso MJ. Regulation of aromatase expression in the anterior amygdala of the developing mouse brain depends on ERβ and sex chromosome complement. Sci Rep. 7(1):5320. 2017 doi: 10.1038/s41598-017-05658-6. 
    9. Dadam FM, Cisternas CD, Macchione AF, Godino A, Antunes-Rodrigues J, Cambiasso MJ, Vivas LM, Caeiro XE. Sex chromosome complement involvement in angiotensin receptor sexual dimorphism. Mol Cell Endocrinol. pii: S0303-7207(17)30154-5. 2017 doi: 10.1016/j.mce.2017.02.041. 
    10. Cisternas CD, Tome K, Caeiro XE, Dadam FM, García-Segura LM, Cambiasso MJ. Sex chromosome complement determines sex differences in aromatase expression and regulation in the stria terminalis and anterior amygdala of developing brain. Mol Cell Endocrinol 414:99-110, 2015. doi: 10.1016/j.mce.2015.07.027.