Forensic Toxicology of Synthetic Drugs WANG Hui-jun
Drug problem is a major social and public security problem in the world. Drug abuse poses a great threat to economic development, social stability and public health. In recent years, synthetic drugs represented by methamphetamine have surpassed traditional drugs such as morphine, heroin, ketamine and become one of the most abused drugs in the world. In order to solve the problem of drug abuse, it is of great theoretical value and practical significance to carry out all-round and multi-level scientific research on drug-related issues. Based on the current situation of drug abuse, this article reviews research progresses on the epidemiology of methamphetamine abuse, the monitoring technology, the basic researches on toxicity damage, the withdrawal drug screening, the related clinical comorbidity and the testing technologies, comprehensively presenting the development trend of methamphetamine abuse related issues.
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.
Abuse of pharmaceutical drugs is a major public health and social problem worldwide. Mostly abused drugs mainly include opioids such as morphine, tramadol, methadone and fentanyl, sedative-hypnotics such as benzodiazepines and non-benzodiazepines, and central stimulants such as Ritalin （methylphenidate）, Adderall （amphetamine and dextroamphetamine） and modafinil. Abuse of pharmaceutical drugs not only causes direct damage to multiple systems of the body, but also significantly increases risks of mental and physical diseases, imposing a heavy burden on individuals, families and society. Therefore, the prevention and control of pharmaceutical drug abuse are of vital importance. The Chinese government has taken strict administration measures for pharmaceutical drugs with abuse risk. However, confronting endless new drugs and changing abuse trends, it is necessary to further strengthen management and prevention of pharmaceutical drugs, monitor the trend of abuse, establish rapid response mechanisms, popularize relevant knowledge, and develop specific therapeutic drugs and intervention means, in order to promote prevention and treatment of pharmaceutical drug abuse.
To investigate the inhibitory effect of cholecystokinin octapeptide （CCK-8） binding to cholecystokinin 2 receptor （CCK2R） on methamphetamine （METH）-induced neuronal apoptosis, and to explore the signal transduction mechanism of β-arrestin 2 in CCK-8 inhibiting METH-induced neuronal apoptosis.
SH-SY5Y cell line was cultured, and HEK293-CCK1R and HEK293-CCK2R cell line were constructed by lentivirus transfection. Small interfering RNA （siRNA） was used to knockdown the expression of β-arrestin 2. Annexin Ⅴ-FITC/PI staining and flow cytometry were used to detect the apoptotic rate of cells, and Western blotting was used to detect the expression of apoptosis-related proteins.
The apoptosis of SH-SY5Y cells was induced by 1 mmol/L and 2 mmol/L METH treatment, the number of nuclear fragmentation and pyknotic cells was significantly increased, and the expression of apoptosis-related proteins Bax and cleaved caspase-3 were increased. CCK-8 pre-treatment at the dose of 0.1 mmol/L and 1 mmol/L significantly reversed METH-induced apoptosis in SH-SY5Y cells, and inhibited cell nuclear fragmentation, pyknosis and the changes of apoptosis-related proteins induced by METH. In lentivirus transfected HEK293-CCK1R and HEK293-CCK2R cells, the results revealed that CCK-8 had no significant effect on METH-induced changes of apoptosis-related proteins in HEK293-CCK1R cells, but it could inhibit the expression level of apoptosis-related proteins in HEK293-CCK2R cells induced by METH. The inhibitory effect of CCK-8 on METH-induced apoptosis was blocked by the knockdown of β-arrestin 2 expression in SH-SY5Y cells.
CCK-8 can bind to CCK2R and exert an inhibitory effect on METH-induced apoptosis by activating the β-arrestin 2 signal.
To study the transcriptomic changes of astrocytes in the brain of rats exposed to methamphetamine （METH） and its possible mechanism in neurotoxicity.
The rats were intraperitoneally injected with METH （15 mg/kg） every 12 h for 8 times in total to establish the subacute rat model of METH. After the model was successfully established, the striatum was extracted, and astrocytes were separated by the magnetic bead method. Transcriptome sequencing was performed on selected astrocytes, and the differentially expressed genes were analyzed by gene ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis.
A total of 876 differentially expressed genes were obtained by transcriptome sequencing, including 321 up-regulated genes and 555 down-regulated genes. GO analysis revealed that differentially expressed genes were mainly concentrated in cell structure, biological process regulation, extracellular matrix and organelle functions. KEGG pathway enrichment analysis showed that steroids biosynthesis, fatty acid biosynthesis, peroxisome proliferators-activated receptor （PPAR）, adenosine 5’-monophosphate-activated protein kinase （AMPK） and other signaling pathways were significantly changed.
METH can cause structural changes of astrocytes through multiple targets, among which cellular structure, steroids biosynthesis and fatty acid biosynthesis may play an important role in nerve injury, providing a new idea for forensic identification of METH related death.
Forensic Toxicology of Synthetic Drugs
