2-iodohexadecanal induces autophagy during goiter involution

Abstract

Background: Iodine plays an important role in thyroid physiology and biochemistry. The thyroid is capable ofproducing different iodolipids such as 2-iodohexadecanal (2-IHDA). Data from different laboratories have shownthat 2-IHDA inhibits several thyroid parameters and it has been postulated as intermediary on the action ofiodide function.Objective: To explore different mechanisms involved during the involution of the hyperplastic thyroid gland ofWistar rats towards normality induced by 2-IHDA. Methods: Goiter was induced by the administration of MMI for10 days, then the treatment was discontinued and Wistar rats were injected with 2-IHDA or KI.Results: During involution, 2-IHDA treatment reduced PCNA expression compared to spontaneous involution. KItreatment caused an increase of Caspase-3 activity and TUNEL-positive cells. In contrast, 2-IHDA failed to alterthis value but induced an increase of LC3B expression. KI but not 2-IHDA led to an increase in peroxides levels,catalase and glutathione peroxidase activity.Conclusions: We demonstrated that 2-IHDA, in contrast to iodide, did not lead to an increase in oxidative stress orapoptosis induction, indicating that the involution triggered by 2-IHDA in Wistar rats, is primarily due to theinhibition of cell proliferation and the induction of autophagy.