The 3-iodothyroacetic acid does not cause change in proteins affected by T1AM.

The 3-iodothyroacetic acid (TA1) derives from the metabolism of 3-iodothyronamine and it is highly produced in cell culture medium supplemented with fetal bovine serum. Previous results indicated that, in models of brain cell lines, exogenous T1AM can increase the phosphorylation of proteins involved in signaling cascade, but this could be a pharmacological effect of TA1. Therefore, we evaluate whether TA1 can reproduce T1AM’s effects in the same experimental conditions. Methods: A hybrid line of cancer cells of mouse neuroblastoma and rat glioma (NG108-15) and a human glioblastoma cell line (U-87 MG) were used. Cell lines were treated with TA1 for 24h, ranging from 0.1 to 10 μM. Uptake, cell viability, and protein expression were assessed. Results: TA1 was taken up by cells, even though its concentration in media was almost unchanged upon 24h of incubation. Cell viability was significantly increased by TA1 10 µM in U87-MG cell line. Western blot analysis indicated that TA1 did not altered the expression (Sirtuin 1, p=NS) or the post-translational modifications (pERK/ERK, pCREB/CREB, p=NS) of proteins involved in signaling cascade that are usually affected by pharmacological doses of T1AM. In conclusion, our observations suggest that TA1, differently from T1AM, does not affect phosphorylation of proteins.