2024-03-29T11:20:38Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/686522022-11-17T02:08:08Zhdl_2115_20051hdl_2115_144Cytotoxic effects of cadmium and zinc co-exposure in PC12 cells and the underlying mechanismRahman, Md. MostafizurUkiana, JunkiUson-Lopez, RachaelSikder, Md. TajuddinSaito, TakeshiKurasaki, Masaakiapoptosisheavy metalscytochrome cDNAcaspase 9glutathione450Cadmium (Cd2+) is a well studied inducer of cellular necrosis and apoptosis. Zinc (Zn2+) is known to inhibit apoptosis induced by toxicants including Cd2+ both in vitro and in vivo. The mechanism of Zn2+-mediated protection from Cd2+-induced cytotoxicity is not established. In this study, we aimed to understand the effects of Zn2+ on Cd2+-induced cytotoxicity and apoptosis using PC12 cells. Cell viability and DNA fragmentation assays in PC12 cells exposed to Cd2+ and/or Zn2+ revealed that Cd2+ (5 and 10 μmol/L) alone induced significant cell death, and co-exposure to Zn2+ (5, 10, and 100 μmol/L) for 48 h had a protective effect. Assessment of intracellular free sulfhydryl levels and lactate dehydrogenase activity suggested that Cd2+ (10 μmol/L) induced oxidative stress and disrupted cell membrane integrity. Addition of Zn2+ (10 and 100 μmol/L) reduced Cd2+-mediated cytotoxicity. Changes in expression of the apoptotic factors Bax, Bcl-2, Bcl-x, and cytochrome c were measured via western blot and expression of caspase 9 was detected via reverse transcriptase polymerase chain reaction. Western blots showed that Zn2+ (10 and 100 μmol/L) suppressed Cd2+-induced apoptosis (10 μmol/L) by reducing cytochrome c release into the cytosol, and downregulating the proapoptotic protein, Bax. In addition, expression of caspase 9 was lower in Cd2+ (5 μmol/L)-treated PC12 cells when co-treated with Zn2+ (2 and 5 μmol/L). These findings suggest that the effective inhibition of Cd2+-induced apoptosis in PC12 cells by Zn2+ might be due to suppression of mitochondrial apoptosis pathway and inhibition of Cd2+-induced production of reactive oxygen species.Journal Articleapplication/pdfhttp://hdl.handle.net/2115/68652https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/68652/1/Manuscript_CBI%20R3%20fresh.pdf0009-2797Chemico-Biological Interactions26941492018-04-02enginfo:pmid/28390674info:doi/10.1016/j.cbi.2017.04.003© 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/author