Copper-induced apoptosis and autophagy through oxidative stress-mediated mitochondrial dysfunction in male germ cells

Zhenlong Kang; Na Qiao; Gaoyang Liu; Hanming Chen; Zhaoxin Tang; Ying Li

doi:10.1016/j.tiv.2019.104639

Copper-induced apoptosis and autophagy through oxidative stress-mediated mitochondrial dysfunction in male germ cells

Toxicol In Vitro. 2019 Dec:61:104639. doi: 10.1016/j.tiv.2019.104639. Epub 2019 Sep 3.

Authors

Zhenlong Kang¹, Na Qiao², Gaoyang Liu², Hanming Chen², Zhaoxin Tang³, Ying Li⁴

Affiliations

¹ State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, People's Republic of China.
² College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, People's Republic of China.
³ College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, People's Republic of China. Electronic address: tangzx@scau.edu.cn.
⁴ College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, People's Republic of China. Electronic address: lying@scau.edu.cn.

PMID: 31491480
DOI: 10.1016/j.tiv.2019.104639

Abstract

Excess copper reduces sperm number and motility but the causes are unclear. We investigated the toxic effects of copper exposure on the immortalized male germ cell line GC-1. Copper addition to cells altered viability and morphology in a dose-dependent manner. Copper addition resulted in increased levels of reactive oxygen species (ROS), malonaldehyde (MDA) and lactate dehydrogenase (LDH) while catalase (CAT) activity and glutathione (GSH) declined. The mitochondrial transmembrane potential and ATP levels decreased in response to copper as did mitochondria fission that led to mitochondrial dysfunction. The apoptosis rate was also proportional to the level of copper in the growth medium. Copper also down-regulated Bcl2 and up-regulated Bax, Casp8 and Casp3 linking the effects of copper to increased apoptosis. The levels of mRNA for the autophagy-related genes (Atg3, Atg5, p62, Lc3b/Lc3a) and proteins (Lc3b/Lc3a, BECN1, Atg5, p62) all increased in copper-treated cells as were levels Lc3 determined by fluorescence microscopy. These results indicated that copper induces apoptosis and autophagy through oxidative stress-mediated mitochondrial dysfunction.

Keywords: Apoptosis; Autophagy; Copper; Mitochondrial dysfunction; Oxidative stress.

MeSH terms

Animals
Apoptosis / drug effects*
Apoptosis Regulatory Proteins / genetics
Autophagy / drug effects
Cell Line
Copper / toxicity*
Germ Cells / drug effects*
Germ Cells / metabolism
Germ Cells / physiology
Male
Membrane Potential, Mitochondrial / drug effects
Mice
Mitochondria / drug effects
Mitochondria / physiology
Oxidative Stress / drug effects
Reactive Oxygen Species / metabolism

Substances

Apoptosis Regulatory Proteins
Reactive Oxygen Species
Copper