Obesogens are a type of
endocrine-disrupting chemicals (EDCs) that disrupt the human endocrine system, resulting in
obesity and
metabolic disease. Several obesogens, including
bisphenol A,
tolylfluanid, and some pesticides, have been identified and studied previously; however, the underlying molecular mechanisms by which obesogens interfere with adipogenesis and induce
insulin resistance in adipocyte remain unknown. This study aims to determine which type of chemical is the most potent obesogen and to investigate its effect on adipogenesis-related gene expressions. 3T3-L1, a pre adipocyte cell line, was differentiated into mature adipocytes with either vehicle or various obesogens, including
bisphenol A,
tolylfluanid, and
endrin, as well as
corticosterone, at the same dose. Subsequently, intracellular and secreted
triglyceride levels were measured, and the expression of genes and
proteins involved in adipogenesis and lipogenesis was investigated. We found that
endrin was the most potent regulator of adipogenic differentiation, as compared to
tolylfluanid,
bisphenol A, and
corticosterone.
Endrin increased intracellular and secreted
triglyceride levels and enhanced the expression of adipogenic
transcription factors as well as the terminal
differentiation marker in a dose-dependent manner. During the early stages of differentiation,
endrin enhanced
mammalian target of rapamycin (mTOR) activity, which was suppressed by the pharmacological blockade of the
protein kinase B-mTOR pathway, with repressed adipogenic differentiation. However,
endrin did not change the expression levels of the downstream members of the mTOR signaling pathway or
proteins related to lipolysis in response to
insulin. Thus, we suggest that
endrin potentiates early-stage adipogenic differentiation by activating the mTOR pathway.