Cadmium sulfate induces apoptosis in planarians

With rapid socio-economic development, heavy metal pollution in water has become common and affects both environment and human health. Cadmium (Cd) has been recognized as one of the heavy metals which cause acute or chronic toxic effects if ingested. Although its toxicity is undisputed, the underlying molecular mechanisms in vivo are not fully understood. Planarians, a model organism famous for their regenerative prowess, have long been utilized to study the effects of chemical exposure. In this study, we observed apoptosis with TUNEL assay in planarians induced by cadmium sulfate (CdSO₄) in a dose-dependent manner. The apoptosis-related genes were detected with quantitative RT-PCR. Significant changes in c-Myc, P53, and BcL-2 were indicated, which may play a partial role in the regulation of the process of apoptosis in the planarians. H&E staining showed that Cd had obvious biological toxicity in the planarians. Here, new insights on metal toxicity mechanisms are provided, contributing to understand how CdSO₄ induces the pathological and physiological processes of apoptosis in the living bodies. Meanwhile, planarians are proved to be a freshwater pollution indicator and toxicological research model.