Single-Cell RNA Sequencing Reveals Cellular and Transcriptional Changes Associated With Traumatic Brain Injury.

Traumatic brain injury (TBI) is currently a substantial public health problem and one of the leading causes of morbidity and mortality worldwide. However, the cellular and transcriptional changes in TBI at single-cell level have not been well characterized. In this study, we reanalyzed a single-cell RNA sequencing (scRNA-seq) dataset of mouse hippocampus to identify the key cellular and transcriptional changes associated with TBI. Specifically, we found that oligodendrocytes were the most abundant cell type in mouse hippocampus, and detected an expanded astrocyte population, which was significantly activated in TBI. The enhanced activity of inflammatory response-related pathways in the astrocytes of TBI samples suggested that the astrocytes, along with microglia, which were the major brain-resident immune cells, were responsible for inflammation in the acute phase of TBI. Hormone secretion, transport, and exocytosis were found upregulated in the excitatory neurons of TBI, which gave us a hint that excitatory neurons might excessively transport and excrete glutamate in response to TBI. Moreover, the ependymal subpopulation C0 was TBI-specific and characterized by downregulated cilium movement, indicating that the attenuated activity of cilium movement following TBI might decrease cerebrospinal fluid flow. Furthermore, we observed that downregulated genes in response to candesartan treatment were preferentially expressed in excitatory neurons and were related to pathways like neuronal systems and neuroactive ligand-receptor interaction, indicating that candesartan might promote recovery of neurons after traumatic brain injury via mediating neuroactive ligand-receptor interactions and reducing excitotoxicity. In conclusion, our study identified key cell types in TBI, which improved our understanding of the cellular and transcriptional changes after TBI and offered an insight into the molecular mechanisms that could serve as therapeutic targets.

[Exploration and characterization of a universal piggyBac transposon vector for efficient transgene studies in sheep].

piggyBac (PB) is a DNA transposon that mediates transposition in various animal cells. As an efficient tool, PB transposons are applied to various transgenic research and optimized for different species, which is an essential means to enhance its versatility. To construct a universal PB transposase (PBase) vector for ovine transgene manipulation, the gene expression box of PBase with optimized bias for sheep codons was inserted into the pBNW-TP1 vector. The vector pBNW-TP2 with a single plasmid was successfully constructed. Then, pBNW-TP2 was transfected into ovine fibroblasts and mammary epithelial cells. The stable transfected cell lines were selected by G418 and the PB transposition sites were determined by Tail-PCR in the stable transfected cell lines. The transposition efficiency was verified by student's t-tests for cell clones with methylene blue staining. The results showed that pBNW-TP2 successfully guided the production of transgenic ovine fibroblasts and mammary epithelial cell lines. The PB transposition test indicated that the pBNW-TP2 vector can be specifically integrated into the TTAA sites of the sheep genome. The statistical analysis of methylene blue staining results suggested that the transgenic efficiency mediated by the pBNW-TP2 vector increased significantly. In summary, we verified and analyzed characteristics of the universal PB transposon vector pBNW-TP2 for sheep in this study, which will provide a scientific basis for future transgenic research mediated by the PB transposon in ovine somatic cells.

[Detection and sequences analysis of bovine hepatitis E virus RNA in Xinjiang Autonomous Region].

Reverse transcription-nested polymerase chain reaction (RT-nPCR) was used to detect HEV (Hepatitis E virus, HEV) RNA in dung or anus-swab samples collected from the cows with the positive anti-HEV antibodies in dairy farms in Xinjiang Autonomous Region. 7 of 60 (11.67%) cows were positive for HEV RNA in one farm. 1 of 31 (3.23%) cows was positive in the other farm. PCR amplification products were cloned, sequenced and analyzed. The result showed that the homology among the 8 bovine HEV ORF2 189bp nucleotide amplification sequences was 96.3%-100.0%, suggesting the same genotype. Compared with HEV genotype 1, 2, 3 and 4 corresponding 189 bp nucleotide sequences, the average homology was 78.5%-86.4%, 81.7%-83.8%, 79.1%-85.3% and 84.3%-95.8% respectively. The maximum homology between 8 nucleotide amplification sequences and one sequence of genotype 4 was 93.2%-95.8%. Based on the sequence of the nucleic acid fragments, a phylogenetic tree was constructed. It was illustrated that 8 bovine HEV ORF2 189bp nucleotide amplification sequences in this study and human C5 strain, swine swC3, swXJ strain belonged to genotype 4. The finding suggested that infection of HEV probably existed in the cow group in Xinjiang Autonomous Region and the cow might be a new animal host except swine in origin of HEV infection.