Exposure of people and animals to environments highly polluted with nickel (Ni) can cause pathologic effects. Ni compounds can induce apoptosis, but the mechanism and the pathway of Ni compounds-induced apoptosis are unclear. We evaluated the alterations of apoptosis, mitochondrial membrane potential (MMP), phosphoinositide-3-kinase (PI3K)/serine-threonine kinase (Akt) pathway, and Bcl-2 family proteins induced by nickel chloride (NiCL2) in the kidneys of broiler chickens, using flow cytometry, terminal deoxynucleotidyl transferase 2’-deoxyuridine 5’-triphosphate dUTP nick end-labeling (TUNEL), immunohistochemstry and quantitative real-time polymerase chain reaction (qRT-PCR). We found that dietary NiCL2 in excess of 300 mg/kg resulted in a significant increase in apoptosis, which was associated with decrease in MMP, and increase in apoptosis inducing factor (AIF) and endonuclease G (EndoG) protein and mRNA expression. Concurrently, NiCL2 inhibited the PI3K/Akt pathway, which was characterized by decreasing PI3K, Aktl and Akt2 mRNA expression levels. NiCL2 also reduced the protein and mRNA expression of anti-apoptotic Bcl-2 and Bcl-xL and increased the protein and mRNA expression of pro-apoptotic Bax and Bak. These results show that NiCL2 causes mitochondrial-mediated apoptosis by disruption of MMP and increased expression of AIF and EndoG mRNA and protein, and that the underlying mechanism of MMP loss involves the Bcl-2 family proteins modulation and PI3K/Akt pathway inhibition.
Guo, H., Cui, H., Peng, X., Fang, J., Zuo, Z., Deng, J., … Deng, J. (2015). Modulation of the PI3K/AKT pathway and Bcl-2 family proteins involved in chicken’s tubular apoptosis induced by nickel chloride (NiCL2). International Journal of Molecular Sciences, 16(9), 22989–23011. https://doi.org/10.3390/ijms160922989