Alteration of microRNA expression in cerebrospinal fluid of unconscious patients after traumatic brain injury and a bioinformatic analysis of related single nucleotide polymorphisms / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>It is becoming increasingly clear that genetic factors play a role in traumatic brain injury (TBI), whether in modifying clinical outcome after TBI or determining susceptibility to it. MicroRNAs are small RNA molecules involved in various pathophysiological processes by repressing target genes at the post- transcriptional level, and TBI alters microRNA expression levels in the hippocampus and cortex. This study was designed to detect differentially expressed microRNAs in the cerebrospinal fluid (CSF) of TBI patients remaining unconscious two weeks after initial injury and to explore related single nucleotide polymorphisms (SNPs).</p><p><b>METHODS</b>We used a microarray platform to detect differential microRNA expression levels in CSF samples from patients with post-traumatic coma compared with samples from controls. A bioinformatic scan was performed covering microRNA gene promoter regions to identify potential functional SNPs.</p><p><b>RESULTS</b>Totally 26 coma patients and 21 controls were included in this study, with similar distribution of age and gender between the two groups. Microarray showed that fourteen microRNAs were differentially expressed, ten at higher and four at lower expression levels in CSF of traumatic coma patients compared with controls (p<0.05). One SNP (rs11851174 allele: C/T) was identified in the motif area of the microRNA hsa-miR-431-3P gene promoter region.</p><p><b>CONCLUSION</b>The altered microRNA expression levels in CSF after brain injury together with SNP identified within the microRNA gene promoter area provide a new perspective on the mechanism of impaired consciousness after TBI. Further studies are needed to explore the association between the specific microRNAs and their related SNPs with post-traumatic unconsciousness.</p>

Bcl-2 gene therapy for apoptosis following traumatic brain injury / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the therapeutic effect of Bcl-2 fusion protein on apoptosis in brain following traumatic brain injury.</p><p><b>METHODS</b>Bcl-2 gene was cloned by RT-PCR. Bcl-2 and EGFP genes were linked together and inserted into pAdeno-X vector. This recombinant vector was packaged into infectious adenovirus in HEK293 cells. Ninety Wistar rats were assigned randomly into experimental group (n=45) and control group (n=45). All rats were subjected to traumatic brain injury. Then recombinant adenovirus (for experimental group) or saline (for control group) was injected into the traumatic brain. The expression of Bcl-2 fusion protein was investigated by Western blotting, immunohistochemistry and fluorescence microscopy. Apoptosis in the injured brain was studied by TUNEL. Animals' behavior capacity was evaluated by tiltboard test.</p><p><b>RESULTS</b>In the experimental group, many fluorescent cells were found around the traumatic locus, which were also proven to be Bcl-2 positive by immunohistochemistry. On the contrary, few Bcl-2 positive cells and no fluorescent cell were detected in the control group. Bcl-2 expression of experimental group was much higher than that of control group, which was illustrated by Western blotting. The apoptosis index of experimental group was 0.027+/-0.005, and that of control group was 0.141+/-0.025 (P < 0.01). Two weeks after injury, animals of the experimental group behaved better than those of the control group.</p><p><b>CONCLUSIONS</b>A recombinant adenovirus vector expressing Bcl-2 fusion protein has been constructed. Bcl-2 fusion protein can suppress apoptosis and promote cell survival. Moreover, the behavior recovery of the injured animal is promoted. Bcl-2 fusion protein provides a way to track the target cells in vivo.</p>