Apoptosis-related genes induced by microcystin-LR in zebrafish

摘要

Microcystins (MCs) are a family of potent hepatotoxins produced by cyanobacteria, and microcystin-LR (MC-LR) is the most commonly encountered type of toxin. Microarray was used to identify the apoptosis-related genes induced by MC-LR in zebrafish. Livers were removed and total RNA isolated at 12, 48 and 96 h post-injection for microarray study. The mRNA abundance of genes was found to be increased, including five TNF related members (apoptosis regulatory protein Siva, TNFα, tumor necrosis factor (ligand) superfamily member 10, tumor necrosis factor-inducible protein 6 and TNF receptor associated factor 2 binding protein), three p53 related genes (tumor protein p53 inducible nuclear protein 1, p53-induced protein phosphatase 1 and a novel apoptosis stimulating protein of p53); Bcl-2 family members (pro-apoptosis gene Bax and anti-apoptosis gene Mcl-1); caspases (caspase y and a PYD and CARD domain-containing protein) and the TGF-beta induced apoptosis protein 2. Real-time PCR was used to study the kinetic transcriptional changes of seven apoptosis-related genes. The Real-time PCR study used RNA from five individual fish at 6, 12, 24, 48 and 72 h post-injection, respectively. Elevated transcription of p53, p53 inducible nuclear protein 1, Mcl-1, TGF-beta induced apoptosis protein 2 could only be detected at 6 h, increased transcription of the antagonist molecules, Bcl-2 and Bax, could be detected at most time points, and the significant change of caspase y could be found at 48 h and 72 h after stimulation. These data suggest that the JNK pathway may be activated by MC-LR induced oxidative stress.