Sensitive genetic biomarkers for determining apoptosis in the brown bullhead (Ameiurus nebulosus).

Biomarkers are necessary for monitoring environmentally induced alterations at the molecular level in order to assess the impact of xenobiotic compounds on organism health. Apoptosis is a highly regulated cellular process that controls programmed cell death and is involved in tumor formation. Apoptosis thus may provide the basis for developing biomarkers for use in the field of ecotoxicology to monitor non-lethal levels of xenobiotic induced cellular stress and toxicity. This study shows that a brown bullhead (Ameiurus nebulosus) fibroblast cell line (BB-2) responds to known apoptotic inducers (staurosporine, cycloheximide, and tumor necrosis factor alpha (TNF-alpha)), as characterized by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP digoxigenin nick end-labelling (TUNEL). Furthermore, we characterized the apoptotic process using a series of newly identified bullhead genetic markers. Exposure to protein kinase C inhibitors altered the transcription of TF-cell apoptosis-related protein (TFAR)-15 and p23 with no effect on p53, inhibitor of apoptosis protein (IAP), or PNAS-2. Inhibition of protein synthesis caused a consistent reduction in the transcription of p53 and PNAS-2. This study demonstrates that our novel transcriptional markers are sensitive biomarkers for the study of the effects of xenobiotic chemicals on apoptosis in the brown bullhead.