Studies On Apoptosis Mechanism Of Chicken Embryo Neuron Induced By Cadmium In Vitro

This study took chicken embryo neurons as a model and added different concentration of CdCl2 into the culture medium. Mechanisms in cadmium-induced apoptosis of chicken embryo neurons were revealed through detecting the activation of the neurons, the capability of adherence, apoptosis, anti-oxidative function, DNA dammages,mitochondria membrane potential(Δψm), Caspase-3, 9 activity, [Ca²⁺]i changes and gene expression. The results showed as follows:1.Inhibition of neurons growth was detected by MTT assay. The result showed that neurons proliferation may be inhibited by CdCl2 and inhibition ratio exhibite dose dependent.2.Phosphatidylserine( PS) was detected by flow cytometry.Neuron morphological changes of apoptosis induced by CdCl2 was observed by AO/EB fluorescent staining, HE staining, transmission electron microscope. Neuron apoptosis induced by CdCl2 was observed by applying agarose gel electrophoresis, TUNEL, it`s proved that CdCl2 can cause neuronal apoptosis.3. The result of detection on anti-oxidative function dedicated that CdCl2 lead to the increase of NOS activity and NO content; the derease of anti-oxidative function, which lead to the oxidative stress. Possibly, this was one of the mechanisms of apoptosis induced by CdCl2.4. Alkality SCGE, detected neuron DNA damage, it showed that CdCl2 induced neuron apoptosis by increasing [Ca²⁺]i, activiting endogenous endonuclease, breaking DNA in nulceosome.5.Δψm and Caspase-3,9 activity were detected by flow cytometry and Colorimetric Assay Kit, respectively. CaM and Caspase-3 mRNA expression were detected by semiquantitative PCR. [Ca²⁺]i was detected by and fluorescence probe. The results proved that CdCl2 can increase [Ca²⁺]i, interfere with the conveyance of [Ca²⁺]i and result in the unbalance of calcium homeostasis, neuronsΔψm was decreased and Caspase-3, Caspase-9 activity were increased, it revealed that CdCl2 induced neuron apoptosis by activating Caspase access.Our study discussed the toxic effect caused by cadmium in cock neurons with celluar and molecular view and revealed that cadmium can increase the activation of neurons, induce oxidative stress, damage the DNA, interfere with calcium homeostasis, influnce the gene expression in cells,induce apoptosis. The mechamisms of toxicity caused by cadmium in cock neurons were illuminated. This reseach was significant to offer the theory for protection and treatment of cadmium poisoning in livestocks, to enirch toxicology and comparative medicine . And, it is also meaningful to ensure the healthy development of graziery, to protect wild fowl and to keep the ecological balance.