Abstract
BACKGROUND: Heavy metals can cause great harm to Siberian tigers in the natural environment. Cadmium (Cd(2+)) is an environmental contaminant that affects multiple cellular processes, including cell proliferation, differentiation, and survival. It has been shown to induce apoptosis in a variety of cell types and tissues. RESULTS: We investigated the apoptotic effects of Cd(2+) on Siberian tiger fibroblasts in vitro. Our research revealed the typical signs of apoptosis after Cd(2+) exposure. Apoptosis was dose- (0-4.8 μM) and duration-dependent (12-48 h), and proliferation was strongly inhibited. Cd(2+) increased the activity of caspase-3, -8, and -9 and disrupted calcium homeostasis by causing oxidative stress and mitochondrial dysfunction. It also increased K(+) efflux and altered the mRNA levels of Bax, Bcl-2, caspase-3, caspase-8, Fas, and p53. CONCLUSIONS: Our results suggest that Cd(2+) triggers the apoptosis of Siberian tiger fibroblasts by disturbing intracellular homeostasis. These results will aid in our understanding of the effects of Cd(2+) on Siberian tigers and in developing interventions to treat and prevent cadmium poisoning.