Neuronutraceuticals Modulate Lipopolysaccharide- or Amyloid-β 1-42 Peptide-Induced Transglutaminase 2 Overexpression as a Marker of Neuroinflammation in Mouse Microglial Cells

Background: Tissue type 2 transglutaminase (TG2, E.C. 2.3.2,13) is reported to be involved in the phagocytosis of apoptotic cells in mouse microglial BV2 cells and peripheral macrophages. In this study, by using lipopolysaccharide (LPS)- or amyloid-β 1-42 (Aβ 1-42) peptide-stimulated microglial cell line BV2 and mouse primary microglial cells, we examined the effects of different neuronutraceutical compounds, such as curcumin (Cu) and N-Palmitoylethanolamine (PEA), known for their anti-inflammatory activity, on TG2 and several inflammatory or neuroprotective biomarker expressions. Methods: Mouse BV2 cells were treated with LPS or Aβ1-42 in the presence of curcumin or PEA, in order to evaluate the expression of TG2 and other inflammatory or neuroprotective markers using Real Time-PCR and Western blot analyses. Results: Curcumin and PEA were capable of reducing TG2 expression in mouse microglial cells during co-treatment with LPS or Aβ 1-42. Conclusions: The results show the role of TG2 as an important marker of neuroinflammation and suggest a possible use of curcumin and PEA in order to reduce LPS- or Aβ1-42-induced TG2 overexpression in mouse microglial cells.