Co-exposure of silica nanoparticles and methylmercury induced cardiac toxicity in vitro and in vivo

Xiaozhe Yang; Lin Feng; Yannan Zhang; Hejing Hu; Yanfeng Shi; Shuang Liang; Tong Zhao; Lige Cao; Junchao Duan; Zhiwei Sun

doi:10.1016/j.scitotenv.2018.03.107

Co-exposure of silica nanoparticles and methylmercury induced cardiac toxicity in vitro and in vivo

Sci Total Environ. 2018 Aug 1:631-632:811-821. doi: 10.1016/j.scitotenv.2018.03.107. Epub 2018 Mar 16.

Authors

Affiliations

¹ Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China.
² Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China. Electronic address: jcduan@ccmu.edu.cn.
³ Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, PR China. Electronic address: zwsun@ccmu.edu.cn.

PMID: 29727991
DOI: 10.1016/j.scitotenv.2018.03.107

Abstract

The released nanoparticles into environment can potentially interact with pre-existing pollution, maybe causing higher toxicity. As such, assessment of their joint toxic effects is necessary. This study was to investigate the co-exposure cardiac toxicity of silica nanoparticles (SiNPs) and methylmercury (MeHg). Factorial design was used to determine the potential joint action type. In vitro study, human cardiomyocytes (AC16) were exposed to SiNPs and MeHg alone or the combination. Higher toxicity was observed on cell viability, cell membrane damage in co-exposure compared with single exposure and control. The co-exposure enhanced the ROS, MDA generation and reduced the activity of SOD and GSH-Px. In addition, the co-exposure induced much higher cellular apoptotic rate in AC16. In vivo study, after SD rats exposed to SiNPs and MeHg and their mixture by intratracheal instillation for 30days, pathological changes (myocardial interstitial edema) of heart were occurred in co-exposure compared with single exposure and control. Moreover obvious ultra-structural changes, including myofibril disorder, myocardial gap expansion, and mitochondrial damage were observed in co-exposure group. The activity of myocardial enzymes, including CK-MB, ANP, BNP and cTnT, were significantly elevated in co-exposure group of rat serum. Meanwhile, the cardiac injury-linked proteins expression showed an increase in SERCA2 and decreased levels of cTnT, ANP and BNP in co-exposure group. Factorial design analysis demonstrated that additive and synergistic interactions were responsible for the co-exposure cardiac toxicity in vitro and vivo. In summary, our results showed severe cardiac toxicity induced by co-exposure of SiNPs and MeHg in both cardiomycytes and heart. It will help to clarify the potential cardiovascular toxicity in regards to combined exposure pollutions.

Keywords: Cardiac toxicity; Co-exposure; Methylmercury; Silica nanoparticles.