Cross - species regulation and underlying mechanisms of parasite - derived non-coding RNAs: a review / 中国血吸虫病防治杂志

Parasite-derived non-coding RNAs (ncRNAs) not only contribute to life activities of parasites, and microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) may generate a competitive endogenous RNA (ceRNA) regulatory network with host miRNAs and mRNAs via extracellular vesicles, thereby participating in infection and pathogenic processes. This article presents an overview of characterizing ncRNAs derived from parasites and the cross-species regulatory role of parasite-derived ncRNAs in host gene expression and its underlying mechanisms.

Effects of Quercetin on nerve regeneration in neonatal rats with hypoxic-ischemic brain damage / 临床儿科杂志

Objective To explore the protective effects of Quercetin on hypoxic ischemic brain damage (HIBD). Methods Forty-eight 7-day-old SD rats were randomly divided into sham-operation group, HIBD group and Que treatment group, 16 rats each. HIBD group and Que treatment group were treated by ligation of right common carotid artery to make anoxia and build HIBD model; sham-operation group had the separation of the right common carotid artery only. Que treatment group were injected intraperitoneally with quercetin (40 mg/kg) once a day for 7 days immediately after modeling while sham-operation group and HIBD group received equivalent normal saline at the same time. The rats in each group were scored of neurological function at 1 h after the last administration, and the ability of spatial learning-memory was tested by Morris water maze at the age of 28 days. After performing the test above, all rats were decapitated and the brains were taken. Pathological changes of hippocampus were observed by HE staining; the expression of brain-derived neurotrophic factor (BDNF) and nerve growth associated protein (GAP-43) in hippocampus CA1 area were detected by immunohistochemistry. Results There were significant differences in neurological deficit score and learning-memory ability among the three groups (P<0.01), and neurological deficit score was the highest and the learning-memory ability was the lowest in HIBD group. Pathological examination showed that the structure of hippocampal neurons was intact in sham-operation group. It was loose and disorder, and even loss of neurons in HIBD group. Compared with the HIBD group, the loose in the structure of hippocampal was lighter, and the number of neurons was increased in the Que treatment group. There was statistical difference in the positive expression of BDNF and GAP-43 in the hippocampal CA1 area among the three groups (P<0.01), with those in HIBD group being lower than in Que treatment group and sham-operation group and those in treatment group being lower than in sham-operation group (P<0.01). Conclusions Quercetin can enhance the expression of BDNF and GAP-43 in hippocampal CA1 region, promote nerve regeneration, improve the long-term learning-memory ability of HIBD neonatal rats, and protect the brain.

The effect of Quercetin on the long-term memory and PARP-1/AIF signal path in neonatal rats with hypoxic-ischemic brain damage / 临床儿科杂志

Objective To explore the effect of Quercetin on the long-term memory and PARP-1/AIF signal path in neonatal rats with hypoxic-ischemic brain damage (HIBD). Methods Fifty-six 7-day-old SD rats were randomly divided into sham-operation group, HIBD group, low dose of Quercetin group (20 mg/kg), and high dose of Quercetin group (40 mg/kg), each of 14 rats. Except for sham-operation group, in the other groups HIBD model were made by right common carotid artery ligation and anoxiate. The Quercetin groups were injected with the corresponding doses of Quercetin immediately once a day continuously for 7 days after the model was made,. Sham-operation group and HIBD group were intraperitoneally injected with normal saline at the same time. Neural function was evaluated by Hanging wire test and Vertical pole test at 21 days old. The capacity of learning and memory was detected by Morris water maze at 28 days old, and then rats were killed and brains were taken. HE was used to observe the pathological changes of hippocampus. Western blot were used to detect the expression of PARP-1 and AIF in hippocampus. Results Compared with sham-operation group, the neural function and learning and memory ability decreased significantly in HIBD group. Those ability in both low dose and high dose of Quercetin groups were remarkably increased in comparison with HIBD group, and there were statistic differences (P??0.05). Conclusion Quercetin could improve long-term learning memory in newborn rats with HIBD, and the mechanism may be down-regulation of PARP-1/AIF cell apoptosis signaling pathway, inhibition of neuronal apoptosis, and thus play a role in protection of brain.

Substrate specificities of bile salt hydrolase 1 and its mutants from Lactobacillus salivarius / 生物工程学报

In order to analyze the correlation between critical residues in the catalytic centre of BSH and the enzyme substrate specificity, seven mutants of Lactobacillus salivarius bile salt hydrolase (BSH1) were constructed by using the Escherichia coli pET-20b(+) gene expression system, rational design and site-directed mutagenesis. These BSH1 mutants exhibited different hydrolytic activities against various conjugated bile salts through substrate specificities comparison. Among the residues being tested, Cys2 and Thr264 were deduced as key sites for BSH1 to catalyze taurocholic acid and glycocholic acid, respectively. Moreover, Cys2 and Thr264 were important for keeping the catalytic activity of BSH1. The high conservative Cys2 was not the only active site, other mutant amino acid sites were possibly involved in substrate binding. These mutant residues might influence the space and shape of the substrate-binding pockets or the channel size for substrate passing through and entering active site of BSH1, thus, the hydrolytic activity of BSH1 was changed to different conjugated bile salt.

Effect of thyrotropin-releasing hormone (TRH) on endotoxic shock in rats / 中国药理学通报

The effect of TRH on endotoxic shock in rats was studied, iv 0. 22-2 mg ?kg-1 TRH significantly reversed hypotension induced by iv coli E. endotoxin (40 mg ?kg-1) into rats and caused a 4. 2 kPa rise in mean arterial pressure (MAP). MAP after TRH administered could be stablized over a higher level than control for 30 min and maintained for 3 h during observation. Interestingly enough, the MAP rose gradually in TRH-treated rats as contrast with increasingly falling of that in control group during the late shock. TRH also improved 24 h sur-vival of shock rats. The dose-response relationship could be observed between 0. 22 ~0. 67 mg ?kg-1 TRH and disappeared over a highest dose (2 mg ?kg-1). It was shown that the best dose to reverse hypotension and to improve survival was 0. 67 mg ?kg-1 TRH. Naloxone 2 mg ?kg-1 showed the nearly same effect as 0. 22 mg ?kg-1 TRH in increasing MAP, but the former had higher 24 h survival of rats than the later.