Fig. 1.

KRIT1 silencing results in increased H₂O₂ levels both in MEF and in hBMEC cells. a) H₂O₂ levels in wild type (K^+/+), KRIT1^−/− (K^−/−), and KRIT1^−/− re-expressing KRIT1 (K9/6) MEF cells left untreated or treated with the antioxidant Tiron (Tir; 5 mM for 24 h). b) H₂O₂ levels in human brain microvascular endothelial cells (hBMEC) transfected with either KRIT1-targeting siRNA (siKRIT1) or a scrambled control (siCTR). Cell extracts containing equal amounts of proteins were analyzed by the Amplex^® Red Hydrogen Peroxide/Peroxidase Assay Kit for assessment of H₂O₂ levels. Fluorescence intensities of the resorufin oxidation product, measured by a microplate reader 30 min after the initiation of the reaction, were expressed in arbitrary units and referred to as H₂O₂ levels relative to the average value of either K9/6 MEF or siCTR hBMEC control cells. Notice that KRIT1 silencing led to a significant increase in H₂O₂ levels both in MEF and in hBMEC cells.