Induction of Apoptosis in Mouse Liver by

Microcystins (MCs) are a family of cyclic heptapeptide hepatotoxins produced by freshwater species of cya-nobacteria that have been implicated in the development of liver cancer, necrosis, and even deadly intrahepatic bleeding. MC-LR, the most toxic MC variant, is also the most commonly encountered in a contaminated aquatic system. This study presents the first data in the toxico-logical research of MCs that combines the use of stand-ard apoptotic assays with transcriptomics, proteomic technologies, and computer simulations. By using histo-chemistry, DNA fragmentation assays, and flow cytometry analysis, we determined that MC-LR causes rapid, dose-dependent apoptosis in mouse liver when BALB/c mice are treated with MC-LR for 24 h at doses of either 50, 60, or 70 g/kg of body weight. We then used gene expres