Amyloid-Beta Induces Different Expression Pattern of Tissue Transglutaminase and Its Isoforms on Olfactory Ensheathing Cells: Modulatory Effect of Indicaxanthin

Herein, we assessed the effect of full native peptide of amyloid-beta (A?) (1-42) and its frag-ments (25-35 and 35-25) on tissue transglutaminase (TG2) and its isoforms (TG2-Long and TG2-Short) expression levels on Olfactory Ensheathing Cells (OECs). Vimentin and Glial Fibril-lary Acid Protein (GFAP) were also studied. The effect of the pre-treatment with Indicaxanthin from Opuntia ficus-indica fruit on TG2 expression levels and its isoforms, cell viability, total Reactive Oxygen Species (ROS), superoxide anion (O2-) and apoptotic pathway activation was assessed. The levels of Nestin and cyclin D1 were also evaluated. Our findings highlight that OECs exposure to A?(1-42) and its fragments induced an increase of TG2 expression levels and a different expression pattern of its isoforms. Indicaxanthin pre-treatment reduced TG2 over-expression modulating the expression of TG2 isoforms. It reduced total ROS and O2- pro-duction, GFAP and Vimentin levels, inhibiting apoptotic pathway activation. It also induced an increase of Nestin and cyclin D1 expression levels. Our data demonstrate that Indicaxanthin pre-treatment stimulated OECs self-renewal through the reparative activity played by TG2. They also suggest that A? might modify TG2 conformation in OECs and that Indicaxanthin pre-treatment might modulate TG2 conformation, stimulating neural regeneration in Alzhèimer Disease.