Oral magnesium prevents acetaminophen-induced acute liver injury by modulating microbial metabolism.

Acetaminophen overuse is a common cause of acute liver failure (ALF). During ALF, toxins are metabolized by enzymes such as CYP2E1 and transformed into reactive species, leading to oxidative damage and liver failure. Here, we found that oral magnesium (Mg) alleviated acetaminophen-induced ALF through metabolic changes in gut microbiota that inhibit CYP2E1. The gut microbiota from Mg-supplemented humans prevented acetaminophen-induced ALF in mice. Mg exposure modulated Bifidobacterium metabolism and enriched indole-3-carboxylic acid (I3C) levels. Formate C-acetyltransferase (pflB) was identified as a key Bifidobacterium enzyme involved in I3C generation. Accordingly, a Bifidobacterium pflB knockout showed diminished I3C generation and reduced the beneficial effects of Mg. Conversely, treatment with I3C or an engineered bacteria overexpressing Bifidobacterium pflB protected against ALF. Mechanistically, I3C bound and inactivated CYP2E1, thus suppressing formation of harmful reactive intermediates and diminishing hepatocyte oxidative damage. These findings highlight how interactions between Mg and gut microbiota may help combat ALF.

Exploration of the microbiome community for saliva, skin, and a mixture of both from a population living in Guangdong.

The identification of biological traces provides vital evidence in forensic reconstruction at crime scenes, especially in sexual offences. Compared with traditional presumptive or confirmatory methods, the microbiome-based method has been proven to be of great value in body fluid identification. Mixture of body fluids or tissue is common in sexual assault cases; thus, it is essential to determine the sources of mixed samples. In this study, 60 samples consisting of skin, saliva, and a mixed model of saliva deposited on facial skin were collected from a population living in Guangdong. Through 16s rDNA high-throughput sequencing, we identified the predominant microbes in saliva samples, viz., Haemophilus parainfluenzae T3T1, Neisseria flava, Gemella haemolysans, Prevotella melaninogenica, and Actinomyces odontolyticus; in skin samples, Cutibacterium acnes and Corynebacterium tuberculostearicum were the predominant species. The microbial composition of the same body fluid or tissue is similar in different individuals. However, among different body fluids or tissue, the composition of microflora in saliva is more stable than that on skin. Additionally, the microbial community in the mixed model of saliva deposited on facial skin from the same and different individuals was clearly determined by the constituent fluids or tissue, apart from the differences among the donors. Overall, the microbiome-based method may have good potential as a tool for identifying single and mixed body fluid or tissue.

Effect of indoor environmental exposure on seminal microbiota and its application in body fluid identification.

Semen is a common body fluid type in forensic sexual assault cases. It is of great significance to effectively identify semen for restoring the crime scene and determining the nature of the case. Nowadays, microbiome-based method shows as a promising tool for forensic body fluid identification. To explore the environmental impact on microbial community of semen and its traceability, 16S rDNA high-throughput sequencing was conducted to ten paired semen samples. Affected by exposure, the diversity of microbial community decreased generally as the genus Staphylococcus exhibited a relatively significant increase. However, the genus Staphylococcus, Corynebacterium, Corynebacterium_1 were observed in almost all 20 samples. Community barplot analysis and heatmap analysis showed composition of the predominant microbe in semen at the phyla and genus level maintained basically, so that it could distinguish from vaginal fluid and saliva regardless of environmental exposure. Based on these results, we believe the application of single microbial marker may limit in semen identification, but the method depending on microbial community might be useful for distinguishing semen even under indoor exposure.

Analysis of 23 Y-STR loci in Chinese Jieyang Han population.

Genetic polymorphisms of 23 Y-chromosomal short tandem repeats (Y-STR) were investigated by PowerPlex® Y23 System in 328 unrelated male participants from Jieyang, Guangdong Province of China. A total of 293 haplotypes were obtained, and the haplotype diversity (HD) and discrimination capacity (DC) were 0.9991 and 0.8933, respectively. By comparing Jieyang population with nine other populations, Jieyang Han showed close genetic relationships with southern China-related Han populations. In conclusion, our study increased the Y-chromosome haplotype reference database and could provide useful information for forensic investigation and population genetics.

Involvement of C/EBPß-related signaling pathway in methamphetamine-induced neuronal autophagy and apoptosis.

Methamphetamine (METH) is a widely abused illicit psychoactive drug. Our previous study has shown that CCAAT-enhancer binding protein ß (C/EBPß) is an important regulator in METH-induced neuronal autophagy and apoptosis. However, the detailed molecular mechanisms underlying this process remain poorly understood. Previous studies have demonstrated that DNA damage-inducible transcript 4 (DDIT4), Trib3 (tribbles pseudo kinase 3), alpha-synuclein (α-syn) are involved in METH-induced dopaminergic neurotoxicity. We hypothesized that C/EBPß is involved in METH-induced DDIT4-mediated neuronal autophagy and Trib3-mediated neuronal apoptosis. We tested our hypothesis by examining the effects of silencing C/EBPß, DDIT4, Trib3 or α-syn with small interfering ribonucleic acid (siRNA) on METH-induced autophagy and apoptosis in the human neuroblastoma SH-SY5Y cells. We also measured the levels of phosphorylated tuberous sclerosis complex 2 (TSC2) protein and Parkin protein level in SH-SY5Y cells. Furthermore, we demonstrated the effect of silencing C/EBPß on METH-caused neurotoxicity in the striatum of rats by injecting LV-shC/EBPß lentivirus using a stereotaxic positioning system. The results showed that METH exposure increased C/EBPß, DDIT4 protein expression. Elevated DDIT4 expression raised up p-TSC2/TSC2 protein expression ratio, inhibited mTOR signaling pathway, activating cell autophagy. We also found that METH exposure increased the expression of Trib3, α-syn, decreased the Parkin protein expression. Lowering levels of Parkin raised up α-syn expression, which initiated mitochondrial apoptosis by down-regulating anti-apoptotic Bcl-2, followed by up-regulation of pro-apoptotic Bax, resulting in translocation of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria to cytoplasm and activation of caspase-dependent pathways. These findings were supported by data showing METH-induced autophagy and apoptosis was significantly inhibited by silencing C/EBPß, DDIT4, Trib3 or α-syn, or by Parkin over-expression. Based on the present data, a novel of mechanism on METH-induced cell toxicity is proposed, METH exposure increased C/EBPß protein expression, triggered DDIT4/TSC2/mTOR signaling pathway, and evoked Trib3/Parkin/α-syn-related mitochondrial apoptotic signaling pathway. Collectively, these results suggest that C/EBPß plays an important role in METH-triggered autophagy and apoptosis and it may be a potential target for therapeutics in METH-caused neurotoxicity.

Specific microbes of saliva and vaginal fluid of Guangdong Han females based on 16S rDNA high-throughput sequencing.

Vaginal fluid and saliva are of great importance in forensic sciences. The identification of vaginal fluid or saliva is especially important in criminal cases. Microbes are considered as a promising marker for the identification of body fluids. In this study, 18 salivary fluids and 18 vaginal fluid samples were collected from 18 healthy women of the Han population in Guangdong province, China. The microbes of the above samples were analyzed by 16S rDNA high-throughput sequencing. The results showed that the microbes whose proportions are over 1% in saliva samples distributed across 12 genera and 57 operational taxonomic units (OTUs), and in vaginal fluid distributed across 4 genera and 9 OTUs. The microbes that dominated in saliva were quite different from those dominated in vaginal fluids. The linear discriminant analysis (LDA) effect size (LEfSe) algorithm was used to screen out the specific microbes of the studied samples, and the results showed that the specific microbes in saliva samples are Haemophilus parainfluenzae, Veillonella parvula, and Aggregatibacter segnis, while in vaginal fluid is Lactobacillus iners.

Genetic polymorphisms of 20 STR loci in a Chaoshan group from Jieyang, China.

We obtained allelic frequencies and forensic parameters of 20 short tandem repeat (STR) loci (D3S1358, FGA, D5S818, D7S820, CSF1PO, D16S539, D19S433, vWA, D8S1179, D18S51, D13S317, TPOX, TH01, D2S1338, D12S391, D1S1656, D21S11, D6S1043, Penta D, Penta E) from 529 unrelated individuals in Jieyang Han population using PowerPlex® 21 (Promega, Madison, Wi, USA). The relationship between the Jieyang Han group and other Han populations was studied and the results showed that the Jieyang Han population had the closest genetic relationship with the Fujian Han population.