ROS-Drp1-mediated mitochondria fission contributes to hippocampal HT22 cell apoptosis induced by silver nanoparticles

Xiaoru Chang; Shuyan Niu; Mengting Shang; Jiangyan Li; Menghao Guo; Wenli Zhang; Zuoyi Sun; Yunjing Li; Rui Zhang; Xin Shen; Meng Tang; Yuying Xue

doi:10.1016/j.redox.2023.102739

ROS-Drp1-mediated mitochondria fission contributes to hippocampal HT22 cell apoptosis induced by silver nanoparticles

Redox Biol. 2023 Jul:63:102739. doi: 10.1016/j.redox.2023.102739. Epub 2023 May 9.

Authors

Xiaoru Chang¹, Shuyan Niu¹, Mengting Shang¹, Jiangyan Li¹, Menghao Guo¹, Wenli Zhang¹, Zuoyi Sun¹, Yunjing Li¹, Rui Zhang¹, Xin Shen¹, Meng Tang¹, Yuying Xue²

Affiliations

¹ Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China.
² Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, 210009, China. Electronic address: yyxue@seu.edu.cn.

Abstract

Silver nanoparticles (AgNPs) have widely used in industrial and medical applications for their excellent antibacterial activities. AgNPs can penetrate into the brain and cause neuronal death, but limited evidence focused on toxic effects and mechanic study in hippocampal neuron. This study aimed to investigate the molecular mechanisms of mitochondrial damage and apoptosis in mouse hippocampal HT22 cells and further to explore role of reactive oxygen species (ROS) and GTPase dynamin-related protein 1 (Drp1) in AgNPs-induced neurotoxicity. Our results showed that acute exposure to AgNPs at low doses (2-8 μg/mL) increased ROS generation, decreased mitochondrial membrane potential (MMP) and ATP synthesis in HT22 cells. In addition, AgNPs promoted mitochondrial fragmentation and mitochondria-dependent apoptosis via excessive mitochondrial fission/fusion by 8 μg/mL AgNPs treatment for 24 h. The mechanism was involved in increased protein expression of Drp1, mitochondrial fission protein 1 (Fis1), mitofusin 1/2 (Mfn1/2) and inhibited optic atrophy 1 (OPA1), and mainly mediated by phosphorylation of Drp1 Ser616. The AgNPs-induced mitochondrial impairment and apoptosis was mainly due to their particle-specific effect rather than silver ions release. Furthermore Drp1-mediated mitochondrial fission contributed to mitochondria-dependent apoptosis induced by AgNPs, all aforementioned changes were significantly rescued by N-acetyl-l-cysteine (NAC) and Mdivi-1 except for OPA1 protein expression. Hence, our results provide a novel neurotoxic mechanism to AgNPs-induced neurotoxicity and revealed that the mechanism of mitochondria-dependent apoptosis in HT22 cells was mediated by excessive activation of ROS-Drp1-mitochondrial fission axis. These findings can deepen current evidences on neurotoxicological evaluation of AgNPs and aid in guiding their proper applications in different areas, especially in biomedical use.

Keywords: Apoptosis; Drp1; Mitochondrial fission; Neurotoxicity; Silver nanoparticles.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Apoptosis
Dynamins / genetics
Dynamins / metabolism
Hippocampus / metabolism
Metal Nanoparticles* / toxicity
Mice
Mitochondria / metabolism
Mitochondrial Dynamics
Reactive Oxygen Species / metabolism
Silver* / toxicity

Substances

Reactive Oxygen Species
Silver
3-(2,4-dichloro-5-methoxyphenyl)-2-sulfanyl-4(3H)-quinazolinone
Dynamins