Leptin Signaling Modulates Expression of Polycomb and Trithorax Complexes in the Brain of Fat Tissue Implanted Polycystic Ovarian Sindrome Mice

Eduardo Henrique da Silva Freitas^1,2, Samuel Marcos Ribeiro de Noronha³, Maria Nazareth Gamboa Ritto^1,4, Carlos Fernandes Baptista^1,4, Ismael Dale Cotrim Guerreiro da Silva¹, Silvana Aparecida Alves Correa-Noronha^1,3*, Ivaldo da Silva¹

¹Gynecology Department, Federal University of Sao Paulo, Paulista School of Medicine (UNIFESP-EPM), Sao Paulo, Brazil.
²General Medicine Department, Federal University of Rio de Janeiro State (UNIRIO), Rio de Janeiro, Brazil.
³Translacional Surgery Division, Surgery Department, Federal University of Sao Paulo, Paulista School of Medicine (UNIFESP-EPM), Sao Paulo, Brazil.
⁴General and Specialized Surgery Department, Federal University of Rio de Janeiro State (UNIRIO), Rio de Janeiro, Brazil.

DOI: 10.4236/ajmb.2014.44020                

Abstract

The Polycystic Ovary Syndrome (PCOS) is the most common androgenic disorder in women during reproductive life. PCOS may also be accompanied by metabolic syndrome and recent studies point to leptin as playing a role in disrupting infertility and in changing the energy balance in obese mice through its action on the hypothalamus. The aim is to assess the expression of the Polycomb & Trithorax Complexes genes in brain of mice transplanted with fat tissue from normal mice, in order to better understand the neuronal mechanisms underlying the reversion of PCOS. Three B6 V-Lepob/J mouse groups: Normal weight, obese and seven-day-treatment obese had their brain RNA extracted and submitted to an 84 Polycomb & Trithorax Complexes genes PCR Array plate and MetacoreTM pathways localization. Genomic profiles obtained were compared to the ones of the normal-weight-mice group. Differentially expressed genes were 13% and 26% respectively to control and treatment. Major changes were in genes: Snai1/31; Smarca1/?17; Dnmt3b/4.7; Ezh1/ 15. Altered genes were associated to canonical pathways and provided 3 networks related to epigenetics. Underlying neuronal changes caused by leptin in obese mice brain, there is an important role being played by the histone code. Here there is evidence that leptin drives the chromatin packing to a more condensed pattern. Upregulation of methyltransferase genes, like Ezh1, favors this thought. In summary the Polycomb & Trithorax complexes might answer for the silencing of some downregulated genes in the obese mice brain when exposed to leptin.

Keywords

Polycistic Ovarian Sindrome, Obesity, Polycomb and Trithorax Complexes, Leptin, Fat Mouse

Conflicts of Interest

The authors declare no conflicts of interest.

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