Gasoline-derived methyl tert-butyl ether as a potential obesogen linked to metabolic syndrome

正The power and efficiency of gasoline engines is often improved through the use of fuel with high octane ratings.The octane rating of fuel could be further increased with oxygenate additives such as alcohols and ethers, with methyl tert-butyl ether (MTBE) being one of the most common gasoline additives. The Agency for Toxic Substances and Disease     

The short-chain perfluorinated compounds PFBS, PFHxS, PFBA and PFHxA, disrupt human mesenchymal stem cell self-renewal and adipogenic differentiation

Per- and polyfluorinated alkyl substances (PFASs) are commonly used in industrial processes and daily life products. Because they are persistent, they accumulate in the environment, wildlife and humans. Although many studies have focused on two of the most representative PFASs, PFOS and PFOA, the potential toxicity of short-chain PFASs has not yet been given sufficient attention. We used a battery of assays to evaluate the toxicity of several four-carbon and six-carbon perfluorinated sulfonates and carboxyl acids (PFBS, PFHxS, PFBA and PFHxA), with a human mesenchymal stem cell (hMSC) system. Our results demonstrate significant cyto- and potential developmental toxicity for all the compounds analyzed, with shared but also distinct mechanisms of toxicity. Moreover, the effects of PFBS and PFHxS were stronger than those of PFBA and PFHxA, but occurred at higher doses compared to PFOS or PFOA.     

Effect of methyl tert-butyl ether on adipogenesis and glucose metabolism in vitro and in vivo

Methyl tert-butyl ether(MTBE), as a widely used gasoline additive, is suspected of being environmentally toxic. MTBE accumulates mainly in adipose tissue, but its effect on obesity or obesity-related metabolic disorders has not been well understood yet. Therefore, we examined the effect of MTBE on the adipose function and the related metabolic processes with both 3T3-L1 cell line and C57 BL/6 J mice model. We found that exposure to MTBE at the environmental relevant concentration(100 μmol/L) could significantly induce differentiation of preadipocyte and disturb insulin-stimulated glucose uptake of mature adipocyte.The in vivo observation in male mice showed a positive correlation of visceral white adipose tissue(vWAT) expansion and cell size increase with MTBE treatment in 14 weeks. Glucose tolerance and insulin sensitivity tests demonstrated that MTBE at 1000 μg/(kg·day)disturbed the systemic glucose metabolism in a gender-specific manner, which might be partly attributed to the alterations of gut microbiota community at genus level with respect to Akkermansia, Clostridium XlVb, and Megamonas. In summary, our study characterized the effect of MTBE on adipose tissue function and glucose homeostasis in vitro and in vivo, and revealed that systemic disorders of the glucose metabolism might be modulated by the related gut microbiota.