Functional characterization of potential regulators of adipogenesis using the zebrafish model

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 685-694-Mechanisms of Obesity
Basic
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-685
Kathrin Landgraf*1, Roy Tauscher1, Antje Berthold2, Wieland Kiess2 and Antje Koerner1
1Childrens Hospital/University of Leipzig, Leipzig, Germany, 2University of Leipzig, Dept. of Women´s & Child Health, Leipzig, Germany
Background: Genome-wide association studies have identified numerous SNPs associated with obesity, implicating many genes for a role in adipocyte biology. In previous studies, we have identified MTCH2, NEGR1 and TMEM18 as regulators of human adipogenesis in vitro.

Objective: The aim of this study is to investigate a potential regulatory role of the obesity-associated genes MTCH2, NEGR1 and TMEM18 during adipose tissue development in vivo by applying the zebrafish as a model organism.

Methods: We cloned and characterized orthologs of MTCH2, NEGR1 and TMEM18 in the zebrafish. We analysed their expression during development from fertilization to adult by quantitative real-time PCR and in situhybridisation. In addition, we assessed the effect of high-fat diet-induced obesity on candidate gene expression.

Results: In situ hybridisation analyses of early developmental stages revealed that mtch2 was mainly expressed in the brain, liver, and intestine, while negr1 was restricted to neural tissues (eyes, brain, spinal cord). In contrast, tmem18 was expressed in the brain and the region surrounding the swim bladder. The expression of mtch2 (5 fold, p<0.001), negr1 (30 fold, p<0.001) and tmem18 (3 fold, p<0.001) was significantly upregulated at 9 dpf. At this stage, we could also detect first visceral adipocytes near the swim bladder of the zebrafish larvae by Nile red staining. Similar to human, the zebrafish mtch2, negr1 and tmem18 were expressed in adipose tissue of adults. Moreover, adipose tissue expression of negr1 (66%±1% of control; p<0.001) and tmem18 (63%±0.6% of control; p<0.001) was significantly decreased in the state of HFD-induced obesity in zebrafish.

Conclusions: In zebrafish, mtch2, negr1 and tmem18 are activated with the start of adipogenesis and regulated by HFD-induced obesity indicating a potential role during adipogenesis in vivo.

Nothing to Disclose: KL, RT, AB, WK, AK

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Previous Abstract | Next Abstract >>