The mechanism of methamphetamine toxicity and addiction is the key research direction of forensic toxicology, and the development of omics technology provides a new platform for further study of this direction. METH toxic damage and addiction are reflected differently in genes, ribonucleic acid (RNA) transcription, protein and metabolism. This article summarizes the achievements and shortcomings of multi-omics technologies such as genome, transcriptome, metabolome and proteome in the study of METH damage and addiction, and discusses the strategies and advantages of multi-omics combined analysis in the study of METH toxic damage and addiction mechanism, in order to provide more useful reference information for forensic toxicology of METH.
Metabolome ; Metabolomics ; Methamphetamine/toxicity* ; Proteome ; Proteomics

OBJECTIVETo investigate the mechanism of methamphetamine (METH)-induced toxicity in PC12 cells.

METHODSPC12 cells were treated with METH for 24 h at the doses of 0, 0.5, 1.0, 1.5, 2.0, or 2.5 mmol/L. The morphological changes of the cells were observed under inverted microscope after the treatment. MTT assay and flow cytometry were used to assess the cell viability and apoptotic rates, respectively, and the level of nitric oxide (NO) was measured by enzyme reduction method.

RESULTSThe PC12 cells exposed to METH were morphologically featured by cell shrinkage, dendrite disruption and disappearance of cell reticular formation. METH exposure caused a dose-dependent reduction in the cell viability (P<0.01), resulting in also increased cell apoptotic rate and significant elevation of NO in the cell culture supernatant (P<0.05).

CONCLUSIONMETH exposure induces cytotoxicity and injury of differentiated PC12 cells, leading to decreased cell viability and increased cell apoptosis and NO level. Cell apoptosis and excessive NO production are involved in METH-induced cytotoxicity.

Animals ; Apoptosis ; drug effects ; Cell Survival ; drug effects ; Methamphetamine ; toxicity ; Neurotoxins ; toxicity ; Nitric Oxide ; metabolism ; PC12 Cells ; Rats

OBJECTIVE: To investigate the activation characteristics of microglia (MG) in the rats striatum with MA-induced neurotoxicity. METHODS: Male Wistar rats were divided randomly into control group (n=24) and experimental group (n=24). The rats of experimental group were injected intraperitoneally with MA (15 mg/kg x 8 injections, at 12 hours interval). The rats of control group were administrated with saline. The tissues of striatum of two rat groups were harvested at 0.5 d, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d and 7 d post initial administrations of MA or saline. The structure changes were observed by transmission electron microscopy and CD-11b immunohistochemistry. The ratio of activated MG was calculated and statistically analyzed. RESULTS: In the control group, the morphological characteristics of the MG showed that the cell bodies were small with slender processes, high electronic density nucleus, and fewer organelles known as the "fork-type". In contrast, the MG in the MA-induced neurotoxicity group displayed larger cell body, shorter cell processes or disappeared, lower electronic density nucleus and rich organelles, resembling "bush-like" or "amoeba-like". The ratio of activated MG in control group was below 0.15 at all timepoints, whereas in the experimental group, the ratio of activated MG increased significantly from day 1 to day 7 (P<0.001). CONCLUSION The continuous MA stimulation of the CNS results in prominent MG activation.
Animals ; Corpus Striatum/pathology* ; Immunohistochemistry ; Male ; Methamphetamine/toxicity* ; Microglia/ultrastructure* ; Microscopy, Electron, Scanning ; Random Allocation ; Rats ; Rats, Wistar ; Staining and Labeling ; Time Factors

This study examined the neuroprotective effect of cluster of differentiation molecule 200 (CD200) against methamphetamine (METH)-induced neurotoxicity. In the in vitro experiment, neuron-microglia cultures were treated with METH (20 μmol/L), METH (20 μmol/L)+CD200-Fc (10 μg/mL) or CD200-Fc (10 μg/mL). Those untreated served as control. Microglia activation expressed as the ratio of MHC-II/CD11b was assessed by flow cytometry. The cytokines (IL-1β, TNF-α) secreted by activated microglia were detected by enzyme-linked immunosorbent assay (ELISA). In the in vivo experiment, 40 SD rats were divided into control, METH, METH+CD200-Fc and CD200-Fc groups at random. Rats were intraperitoneally injected with METH (15 mg/kg 8 times at 12 h interval) in METH group, with METH (administered as the same dose and time as the METH group) and CD200-Fc (1 mg/kg at day 0, 2, 4 after METH injection) in METH+CD200-Fc group, with CD200-Fc (1 mg/kg injected as the same time as the METH+CD200-Fc group) or with physiological saline solution in the control group. The level of striatal dopamine (DA) in rats was measured by high-performance liquid chromatography (HPLC). The microglial cells were immunohistochemically detected for the expression of Iba-1, a marker for microglial activation. The results showed that METH could increase the microglia activation in the neuron-microglia cultures and elevate the secretion of IL-1β and TNF-α, which could be attenuated by CD200-Fc. Moreover, CD200-Fc could partially reverse the striatal DA depletion induced by METH and reduce the number of activated microglia, i.e. Iba-1-positive cells. It was concluded that CD200 may have neuroprotective effects against METH-induced neurotoxicity by inhibiting microglial activation and reversing DA depletion in striatum.
Animals ; Animals, Newborn ; Antigens, CD ; administration & dosage ; Cells, Cultured ; Coculture Techniques ; Corpus Striatum ; cytology ; drug effects ; immunology ; Cytokines ; immunology ; Dopamine ; immunology ; Drug Interactions ; Male ; Methamphetamine ; toxicity ; Microglia ; drug effects ; immunology ; Neurons ; metabolism ; Rats ; Rats, Sprague-Dawley