Citation

Li X, Wu F, Xue L, Wang B, Li J, Chen Y, Chen T. Hum. Exp. Toxicol. 2018; 37(5): 486-495.

Affiliation

Key Laboratory of the Health Ministry for Forensic Medicine, Key Laboratory of the Ministry of Education for Environment and Genes Related to Diseases, Forensic Medicine College, Xi'an Jiaotong University, Xi'an, People's Republic of China.

Copyright

(Copyright © 2018, SAGE Publishing)

DOI

10.1177/0960327117714039

PMID

28621212

Abstract

Macrophages, especially their activation state, are closely related to the progression of neurotoxicity. Classically activated macrophages (M1) are proinflammatory effectors, while alternatively activated macrophages (M2) exhibit anti-inflammatory properties. As a powerful addictive psychostimulant drug, coupled with its neurotoxicity, methamphetamine (Meth) abuse may lead to long-lasting abnormalities in the neuronal system. The present study investigated the effect of Meth at subtoxic concentration on macrophage activation state and its underlying toxicity to neuronal cells. PC12 and Murine RAW264.7 cells were coincubated with Meth to test its toxicity. 3-(4,5-Dimethylthiazol)-2,5-diphenyltetrazolium-bromide, enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot assays were performed to evaluate the toxicity, cytokine secretion, gene, and protein expression.

RESULTS showed that cytotoxicity was enhanced on PC12 cells after coculturing with RAW264.7 stimulated with Meth. RAW264.7 macrophages tended to switch to the M1 phenotype, releasing more nitric oxide and proinflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin (IL)-12, and IL-1β, while decreasing the release of anti-inflammatory cytokine IL-10 after treatment with Meth. Meth upregulated the gene expression of IL-6, IL-1β, and TNFα and downregulated the expression of Arg-1, IL-10, and KLF4. Meth could also upregulate the protein expression of IL-1β and TNF α and downregulate the expression of Arg-1 and KLF4. However, the abovementioned effects induced by Meth were abolished by the addition of dopamine receptor D3 antagonist. In conclusion, our study demonstrated that Meth promoted macrophage polarization from M0 to M1 and enhanced inflammatory response, which provided the scientific rationale for the neurotoxicity caused by the chronic use of Meth.

Language: en

Keywords

Methamphetamine; PC12 cells; inflammatory response; macrophage; neurotoxicity