Chronic inflammation and reactive oxygen species (ROS) production induced by crystalline silica are involved in the development of silicosis and lung cancer pathogenesis. ROS can generate lipid peroxydation of cell membranes that can produce methylglyoxal (MG), a strong cell proliferation inhibitor and apoptosis inducer. MG is naturally removed by glyoxalase I (GI) and glyoxalase II (GII) through a glutathione (GSH) dependent mechanism. Therefore mRNA expression of glyoxalases is correlated to MG concentration and oxidative stress.
Objectives: evaluate oxidative stress induced by crystalline silica by glyoxalases mRNA expression and methylglyoxal concentration
Material and methods: In bronchial epithelial cell culture (BEAS-2B), exposed to 50 microg/cm2 crystalline silica (Min-U-Sil 5), for 2, 6, 12, and 24 hours, GI and GII mRNA levels and MG intracellular concentration were measured respectively by Real-Time PCR and HPLC.
Results: Crystalline silica exposure induced a significant reduction in mRNA expression of glyoxalases and an increase of MG intracellular concentration.
Conclusions: The results suggest a possible use of MG and mRNA expression of GI and GII as crystalline silica induced oxidative stress indicators.