Bisphenol A (BPA), a member of the environmental endocrine disruptors (EDCs), has recently received increased attention because of its effects on brain insulin resistance. Available data have indicated that brain insulin resistance may contribute to neurodegenerative diseases. However, the associated mechanisms that underlie BPA-induced brain-related outcomes remain largely unknown. In the present study, we identified significant insulin signaling disturbances in the SH-SY5Y cell line that were mediated by BPA, including the inhibition of physiological p-IR Tyr1355 tyrosine, p-IRS1 tyrosine 896, p-AKT serine 473 and p-GSK3α/β serine 21/9 phosphorylation, as well as the enhancement of IRS1 Ser307 phosphorylation; these effects were clearly attenuated by insulin and rosiglitazone. Intriguingly, Alzheimer’s disease (AD)-associated pathological proteins, such as BACE-1, APP, β-CTF, α-CTF, Aβ 1–42 and phosphorylated tau proteins (S199, S396, T205, S214 and S404), were substantially increased after BPA exposure, and these effects were abrogated by insulin and rosiglitazone treatment; these findings underscore the specific roles of insulin signaling in BPA-mediated AD-like neurotoxicity. Thus, an understanding of the regulation of insulin signaling may provide novel insights into potential therapeutic targets for BPA-mediated AD-like neurotoxicity.

No abstract

-Methamphetamine (METH) is a potent and highly addictive central nervous system stimulant. The association between METH exposure and Alzheimer's disease (AD) has gained more attention, but, the mechanisms behind METH-induced neuron-related adverse outcomes remain poorly understood. With the western blot assay, our results revealed that METH exposure significantly increased the expression of AD-associated pathological proteins, including the amyloid precursor protein (APP) and the phosphorylated tau protein (p-tau). Meanwhile, the insulin signaling was disturbed after the administration of METH, since the key insulin signaling proteins, such as p-AKT, p-GSK3α, p-GSK3β and pERK , were reduced. Additionally, the linking between the pathological proteins and the insulin signaling mediated by METH in the present work was verified by the treatment with the insulin signaling enhancer rosiglitazone, which was shown to improve the insulin signaling and decrease APP and p-tau expression. Thus, targeting insulin signaling may provide novel insights into potential therapeutic intervention for METHmediated AD-like neurodegeneration.

No abstract

No abstract