Apoptotic responses of Carassius auratus lymphocytes to nodularin exposure in vitro

作者：Zhang, Hangjun^*; Shao, Dandan; Wu, Yingzhu; Cai, Chenchen; Hu, Ciming; Shou, Xiaolu; Dai, Bingru; Ye, Binhui; Wang, Mengdi; Jia, Xiuying

来源：Fish & Shellfish Immunology, 2012, 33(6): 1229-1237.

DOI：10.1016/j.fsi.2012.08.016

• Apoptosis
• Nodularin
• Mitochondrial pathway
• Fish lymphocytes
• ROS

Nodularin, a metabolite of Nodularin spumigena, is widely detected in water blooms worldwide and causes serious negative effects on fish. The apoptosis-related cytotoxic effects and mechanisms of nodularin on Carassius auratus lymphocytes were investigated. Transmission electron microscopy results showed that nodularin-treated lymphocytes display a series of morphological changes, including condensed cytoplasm, nuclear chromatin agglutination and marginalization. DNA fragmentation was verified by the DNA-ladder and formation of sub-G1 DNA peaks. These cell characteristics confirmed the occurrence of apoptosis in lymphocytes. Flow cytometric results showed that the percentages of apoptotic cells incubated with 1, 5,10, and 100 mu g/L nodularin for 12 h reached 15.76%, 17.36%, 20.34% and 44.21%, respectively: controls showed low rates of apoptosis (2.4%). The mechanism of apoptosis induced by nodularin was determined, and results showed that nodularin exposure caused a significant increase in intracellular reactive oxygen species (ROS), loss of mitochondrial transmembrane potential in a dose-dependent manner, upregulation of intracellular Ca2+, downregulation of Bcl-2 and upregulation of Bax expression at the mRNA and protein levels, and activation of caspase-3 and caspase-9 without caspase-8. In summary, all the results suggest that nodularin induces lymphocyte apoptosis via the mitochondrial apoptotic pathway and destroys the immune response of fish.

• 出版日期2012-12
• 单位杭州师范大学