Original Contribution SCAVENGING SYSTEM EFFICIENCY IS CRUCIAL FOR CELL RESISTANCE TO ROS-MEDIATED METHYLGLYOXAL INJURY F ERNANDA AMICARELLI ,* S ABRINA C OLAFARINA , † F RANCA C ATTANI ,* ANNAMARIA C IMINI ,* C ARMINED I I LIO , † M ARIA P AOLA C ERU ,* andM ICHELE M IRANDA * *Department of Basic and Applied Biology, Faculty of Science, L’Aquila University, L’Aquila,Italy; and † Department of Biomedical Sciences, Faculty of Medicine, G. D’Annunzio University, Chieti, Italy (Received 8 November 2002; Revised 19 May 2003; Accepted 27 June 2003) Abstract—Methylglyoxal is a reactive dicarbonyl compound endogenously produced mainly from glycolytic interm diates. Recent research indicates that methylglyoxal is a potent growth inhibitor and genotoxic agent. The antiprolif- erative activity of methylglyoxal has been investigated for pharmacological application in cancer chemotherapy. However, various cells are not equally sensitive to methylglyoxal toxicity. Therefore, it would be important to esta the cellular factors responsible for the different cell-type specific response to methylglyoxal injury, in order to avo risk of failure ofa therapy based on increasing the intracellular level of methylglyoxal. To this purpose, we comparatively evaluated the signaling transduction pathway elicited by methylglyoxal in human glioblastoma (AD and neuroblastoma (SH-SY 5Y) cells. Results show that methylglyoxal causes early and extensive reactive oxygen species generation in both cell lines. However, SH-SY 5Y cells show higher sensitivity to methylglyoxal challenge to a defective antioxidant and detoxifying ability that, preventing these cells from an efficient scavenging action, extensive caspase-9 dependent apoptosis. These data emphasize the pivotal role of antioxidant and detoxifying sy in determining the grade of sensitivity of cells to methylglyoxal. © 2003 Elsevier Inc. Keywords—Methylglyoxal, ROS, Glioblastoma cells, Neuroblastoma cells, Antioxidant enzymes, Glyoxalase syste Glutathione, Apoptosis, PPARs,Free radicals INTRODUCTION Methylglyoxal (2-oxopropanal, MG) is a reactive dicar- bonylcompound physiologically produced by various metabolic pathways, including the enzymatic and non- enzymatic elimination of phosphate from triose-phos- phate glycolytic intermediates or the metabolism of ac- etone and aminoacetone [1,2]. However, under normal metabolic conditions, the last two pathways seem to be of minorimportance, so thatmethylglyoxal formation can be considered an intrinsic feature of the Embden- Meyerhof pathway. It is known that MG, albeit a natural biological product, is cytotoxic, as it can bind to proteins and nucleic acids, forming stable adducts [3,4].The cytotoxic effect of MG to tissues and cells often occurs through the induction of apoptosis [5,6] with possible involvement, in some cases, of the mitogen-activated protein kinases family (MAPK) and reactive oxygen species (ROS) production [7–9]. However, the molec- ular mechanism underlying this process is not yet fully understood. MG can yield advanced glycation end products (AGEs) via nonenzymatic glycation of pro- teins through a process that has been reported to cause free radicals production [10,11]. Under hyperglycemic conditions, an increase in the concentration of MG has been observed in human tissues and body fluids that seemsto be responsible fordiabetic complications [12].Recentresearch indicates that MG is a potent growth inhibitor and genotoxic agent. MG induces growth arrest in the G 1 phase of the cell cycle through inhibition of DNA synthesis in several cells [6,13]. In this context, we have shown that MG is also able to induce cellgrowth retardation and malformation in developing embryos [14]. These effects are mediated by mitochondria derangement associated with strong reduction of ATP production [15]. Address correspondence to: Dr. Fernanda Amicarelli, Department of Basic and Applied Biology, Faculty of Science, L’Aquila University, via Vetoio Coppito, 67100 L’Aquila, Italy;Tel: ⫹39 (862) 433275; Fax: ⫹39 (862) 433273; E-Mail: fernanda.amicarelli@univaq.it. Free Radical Biology & Medicine, Vol. 35,No.8, pp.856 – 871, 2003 Copyright © 2003 Elsevier Inc. Printed in the USA. All rights reserved 0891-5849/03/$–see front matter doi:10.1016/S0891-5849(03)00438-6 856