Periodic Reporting for period 1 - EPOC (Understanding the molecular basis of stochastic bi-stable obesity)
Okres sprawozdawczy: 2016-12-01 do 2018-11-30
People are not all equal when it comes to emergence of obesity. Indeed, some populations seem protected, others seem prone to its development. Population level phenotypic variation, which describes the variability of a phenotype in a given population, is thought to serve as a mechanistic platform for adaptation and evolution. Phenotypic variation can be of genetic and/or epigenetic origin.
Whereas, the last decade has seen much progress in obesity genetics, our understanding of epigenetic regulation of the disease is poor.
Our lab recently published data about specific mutant mice developing an unprecedented bi-stable stochastic obesity phenotype. Approximately 20% of the genetically identical, littermate-controlled heterozygous mutant mice develop obesity while the remaining ~80% remain as lean as wild-type littermates, resulting in a bi-modal body weight distribution in the population. Here, we proposed to map the molecular basis of a chromatin state dependent epigenetic switch that to the best of our knowledge buffers metabolic programming, establishes phenotypic bi-stability and thereby generate a deeper understanding of the mechanisms underlying bi-stable obesity.
In the same time, we began to set up a sufficient matrix for determination of high-confidence core molecular patterns specific to each model and to stochastic obesity in general. This matrix is based on in vivo analysis (indirect calorimetry during fed state) and ex vivo analysis (blood profile and adipocytes profile).
This study clearly demonstrated a new example of phenotypic co-variation with specific molecular mechanisms underlying this bi-stable obesity. We have still datas to analyze and experiments to perform before the publication step, but the results were presented in differents scientific meetings (TRIRHENA Chromatin club meeting, MPI-IE Institute Seminar, MPI-IE Epigenetics meeting).