Toxicogenomics in the 3T3-L1 Cell Line, a New Approach for Screening of Obesogenic Compounds

Abstract

The obesogen hypothesis states that together with an energy imbalance between calories consumed and calories expended, exposure to environmental compounds early in life or throughout lifetime might have an influence on obesity development. In this work, we propose a new approach for obesogen screening, i.e., the use of transcriptomics in the 3T3-L1 pre-adipocyte cell line. Based on the data from a previous study of our group using a lipid accumulation based adipocyte differentiation assay, several human-relevant obesogenic compounds were selected: reference obesogens (Rosiglitazone, Tributyltin), test obesogens (Butylbenzyl phthalate, butylparaben, propylparaben, Bisphenol A), and non-obesogens (Ethylene Brassylate, Bis (2-ethylhexyl)phthalate). The high stability and reproducibility of the 3T3-L1 gene transcription patterns over different experiments and cell batches is demonstrated by this study. Obesogens and non-obesogen gene transcription profiles were clearly distinguished using hierarchical clustering. Furthermore, a gradual distinction corresponding to differences in induction of lipid accumulation could be made between test and reference obesogens based on transcription patterns, indicating the potential use of this strategy for classification of obesogens. Marker genes that are able to distinguish between non, test, and reference obesogens were identified. Well-known genes involved in adipocyte differentiation as well as genes with unknown functions were selected, implying a potential adipocyte-related function of the latter. Cell-physiological lipid accumulation was well estimated based on transcription levels of the marker genes, indicating the biological relevance of omics data. In conclusion, this study shows the high relevance and reproducibility of this 3T3-L1 based in vitro toxicogenomics tool for classification of obesogens and biomarker discovery. Although the results presented here are promising, further confirmation of the predictive value of the set of candidate biomarkers identified as well as the validation of their clinical role will be needed.

Transcriptional profiling and biological pathway analysis of human equivalence PCB exposure in vitro: Indicator of disease and disorder development in humans

“…Under the present investigation, we observed that gene expression changes resulting from the exposure may indeed reflect an investigational approach that highlights biomarkers of specific diseases and disorders, e.g. metabolic disorders (including obesity and diabetes) cardiovascular, endocrine disruption, and cancers, in accord with results observed in epidemiological settings (Langer et al, 2014; Arrebola et al, 2014; Recio-Vega et al, 2013; Lee et al, 2014; Wadzinski et al, 2014; Pereira-Fernandes et al, 2014; Sexton et al, 2013, Casas et al, 2014). Research utilizing PBMC cells in human are now being widely used to test for the efficacy of new drugs and treatments, to divulge the differential gene expression patterns induced by toxicity, and to study downstream effectors, all of which can be used as a potential source for developing disease-specific biomarkers (Reynes et al, 2014; Saidijam et al, 2014; Roccaet et al, 2014; Kong 2014).…”

Metabolism disrupting chemicals and metabolic disorders

“…Several laboratories have shown that TBT stimulates adipogenesis in preadipoctyes in vitro [369-371] [372]. Prenatal exposure to TBT results in increased lipid accumulation, increased adipose tissue mass (due to both adipocyte hyperplasia and hypertrophy), and reduced muscle mass that persists into adulthood and across generations in mouse models [309, 367] and increased adiposity in zebrafish [373].…”

Effects of long-term endocrine disrupting compound exposure on Macaca mulatta embryonic stem cells

“…In studies involving induction of differentiation events from embryos or stem cells, prolonged treatment of up to two weeks in vitro revealed similar small numbers of genes induced or repressed by EDCs [71]. The numbers of affected genes can be much higher for specialized somatic cell lines [72]. In studies of ES or pluripotent cell exposures to higher EDC doses for short periods of 72 h or less, larger numbers of affected genes are seen for some EDCs [73–75], but small numbers for others [75].…”