Dexmedetomidine inhibits microglial activation through SNHG14/HMGB1 pathway in spinal cord ischemia-reperfusion injury mice.

OBJECTIVE: Microglial activation is an essential pathological mechanism of spinal cord ischemia-reperfusion injury (SCIRI). Previous studies showed dexmedetomidine (DEX) could alleviate SCIRI while the mechanism was not clear. This study aims to investigate the role of DEX in microglial activation and clarify the underlying mechanism. METHODS: The motion function of mice was quantified using the Basso Mouse Scale for Locomotion. The expression of long non-coding RNA (lncRNA) small nucleolar RNA host gene 14 (SNHG14) was determined by qRT-PCR. The expression of high-mobility group box 1 (HMGB1) was measured by western blot. The activation of microglia was evaluated by the expression of ED-1 and the levels of TNF-α and IL-6. The interplay between SNHG14 and HMGB1 was confirmed with RNA pull-down and RIP assay. The stability of HMGB1 was measured by ubiquitination assay and cycloheximide-chase assay. RESULTS: DEX inhibited microglial activation and down-regulated SNHG14 expression in SCIRI mice and oxygen and glucose deprivation/reoxygenation (OGD/R)-treated primary microglia. Functionally, SNHG14 overexpression reversed the inhibitory effect of DEX on OGD/R-induced microglial activation. Further investigation confirmed that SNHG14 bound to HMGB1, positively regulated HMGB1 expression by enhancing its stability. In addition, the silence of HMGB1 eliminated the pro-activation impact of SNHG14 overexpression on DEX-treated microglia under the OGD/R condition. Finally, in vivo experiments showed SNHG14 overexpression abrogated the therapeutic effect of DEX on SCIRI mice by up-regulating HMGB1. CONCLUSION: DEX accelerated HMGB1 degradation via down-regulating SNHG14, thus inhibiting microglial activation in SCIRI mice.

Propofol alleviates oxidative stress via upregulating lncRNA-TUG1/Brg1 pathway in hypoxia/reoxygenation hepatic cells.

Reducing oxidative stress is an effective method to prevent hepatic ischaemia/reperfusion injury (HIRI). This study focuses on the role of propofol on the oxidative stress of hepatic cells and the involved lncRNA-TUG1/Brahma-related gene 1 (Brg1) pathway in HIRI mice. The mouse HIRI model was established and was intraperitoneally injected with propofol postconditioning. Hepatic injury indexes were used to evaluate HIRI. The oxidative stress was indicated by increasing 8-isoprostane concentration. Mouse hepatic cell line AML12 was treated with hypoxia and subsequent reoxygenation (H/R). The targeted regulation of lncRNA-TUG1 on Brg1 was proved by RNA pull-down, RIP (RNA-binding protein immunoprecipitation) and the expression level of Brg1 responds to silencing or overexpression of lncRNA-TUG1. Propofol alleviates HIRI and induces the upregulation of lncRNA-TUG1 in the mouse HIRI model. Propofol increases cell viability and lncRNA-TUG1 expression level in H/R-treated hepatic cells. In H/R plus propofol-treated hepatic cells, lncRNA-TUG1 silencing reduces cell viability and increased oxidative stress. LncRNA-TUG1 interacts with Brg1 protein and keeps its level via inhibiting its degradation. Brg1 overexpression reverses lncRNA-TUG1 induced the reduction of cell viability and the increase in oxidative stress. LncRNA-TUG1 silencing abrogates the protective role of propofol against HIRI in the mouse HIRI model. LncRNA-TUG1 has a targeted regulation of Brg1, and thereby affects the oxidative stress induced by HIRI. This pathway mediates the protective effect of propofol against HIRI of hepatic cell.

Genetic diversity of Borrelia burgdorferi sensu lato isolates from Northeastern China.

Thirty-two strains of Borrelia burgdorferi sensu lato were isolated from Ixodes persulcatus ticks collected from northeastern China from May to June in 2004 and 2005. Restriction fragment length polymorphism (RFLP) analysis and sequence analysis of 5S-23S rRNA intergenic spacer revealed that 29 (90.6%) belonged to Borrelia garinii, demonstrating B, C, and a unique pattern. The remaining three isolates (9.4%) were Borrelia afzelii with pattern D. The phylogenetic analysis based on 5S-23S rRNA intergenic spacer showed that B. garinii and B. afzelii genospecies clustered into two separate lineages. B. garinii strains were classified into three different branches: All the strains with RFLP pattern C were in the same branch, strain VH10 with a unique RFLP pattern clustered with strains VH9 and MDH2 with pattern B, and the rest of the strains with pattern B constitute another branch. These findings demonstrate the genetic diversity of B. burgdorferi sensu lato isolates from northeastern China.

Genetic diversity of Borrelia burgdorferi sensu lato isolates from Northeastern China.

Thirty-two strains of Borrelia burgdorferi sensu lato were isolated from Ixodes persulcatus ticks collected from northeastern China from May to June in 2004 and 2005. Restriction fragment length polymorphism (RFLP) analysis and sequence analysis of 5S-23S rRNA intergenic spacer revealed that 29 (90.6%) belonged to Borrelia garinii, demonstrating B, C, and a unique pattern. The remaining three isolates (9.4%) were Borrelia afzelii with pattern D. The phylogenetic analysis based on 5S-23S rRNA intergenic spacer showed that B. garinii and B. afzelii genospecies clustered into two separate lineages. B. garinii strains were classified into three different branches: All the strains with RFLP pattern C were in the same branch, strain VH10 with a unique RFLP pattern clustered with strains VH9 and MDH2 with pattern B, and the rest of the strains with pattern B constitute another branch. These findings demonstrate the genetic diversity of B. burgdorferi sensu lato isolates from northeastern China.

Isolation and genetic characterization of hantaviruses carried by Microtus voles in China.

To gain more insights into hantavirus distribution in China, Microtus fortis were caught in Jilin province and M. maximowiczii in the Inner Mongolia Autonomous Region. Hantavirus specific RNA was detected by RT-PCR in 3 out of 26 M. fortis and 5 out of 64 M. maximowiczii. Two hantaviruses (Fusong-Mf-682 and Yakeshi-Mm-59) were isolated successfully in cell culture and their S and M segment nucleotide sequences were determined. Phylogenetic analysis of the S and M segment sequences revealed that the Mf-originated strains from Fusong were closely related to Vladivostok hantavirus (VLAV) with 99% nucleotide identity, but differed from the Yakeshi-Mm strains, with an amino acid divergence of more than 8.8% for the N protein and 11.8% for the GnGc proteins. Yakeshi-Mm strains were closely related to the Khabarovsk hantavirus (KHAV) isolated earlier from M. fortis in Khabarovsk, with an amino acid sequence identity of more than 98.4% for the S segment and 95.6% for the M segment. On phylogenetic trees, Yakeshi-Mm strains clustered together with KHAV and Topografov virus (TOPV) carried by Lemmus sibiricus. The results suggest that the hantavirus carried by M. fortis in China belongs to VLAV type and should be considered as a distinct hantavirus species. They also suggest that M. fortis is the natural host of VLAV (including Fusong-Mf strains), whereas M. maximowiczii is the natural host of KHAV including Yakeshi-Mm strains. Thus, in addition to Hantaan, Seoul, Dabieshan and Puumala-like Hokkaido viruses, at least two other hantaviruses, namely KHAV and VLAV, are circulating in China.

[Expressions of LRP, GST-pi and MRP1 in acute leukemia patients and its clinical significance].

This study was purposed to investigate the relationship of expressions of gluthatione-S-transferase-pi (GST-pi), multidrug resistance protein-1 (MRP-1), lung resistance protein (LRP) with multidrug resistance of acute leukemia (AL), the correlation between 3 kinds protein expressions and the correlation of their protein expression with clinical features of AL patients. The S-P immunohistochemical staining method was used to determine the expressions of GST-pi, MRP1 and LRP proteins in 80 AL patients and 30 normal subjects. The results showed that there was the correlation between GST-pi, MRP1, LRP protein expression and chemotherapy resistance, meanwhile CR rates of patients with positive expression of those proteins were lower than that of patients with negative expression (P<0.05), so those protein expressions may be accounted for poor prognosis. There was the positive relationship between expression of GST-pi and MRP1 in refractory group (r=0.851, P<0.01). It is concluded that co-examination of GST-pi and MRP1 has greater significance than examination of one kind of protein in evaluating poor prognosis of leukemia patients. LRP protein expression increase obviously when WBC counts >or= 10 x 10(9)/L (63.6%, P<0.05), therefore LRP protein has great judging value for evaluating drug resistance and prognosis of acute leukemia patients whose peripheral blood WBC counts were high.

[Expression of cyclin g2 mRNA in patients with acute leukemia and its clinical significance].

To evaluate the expression of cyclin G2 mRNA in patients with acute leukaemia (AL) and its clinical value, the expression of cyclin G2, G1 and P53 mRNA in the bone marrow from 74 AL patients and 10 normal individuals as control were detected with reverse transcription polymerase chain reaction (RT-PCR). The positive segment of cyclin G2 was analyzed by DNA sequencing. The results showed that (1) the positive rate and the expressing level of cyclin G2 in AL patients (52.7%, 0.552 +/- 0.498) were significantly lower than those in normal control (100%, 1.953 +/- 0.675) (P < 0.01); (2) among new diagnosed AL patients, the complete remission (CR) rate (69.2%) in the positive cyclin G2 patients was higher than that (40%) in negative cyclin G2 patients (P < 0.05); (3) the positive rate of cyclin G2 (43.6%) in resistance group was significantly higher than that (68.6%) in sensitive group (P < 0.01); (4) following-up for 14.3 month (11 - 18.5 month) in 28 AL patients with CR, there were 10 relapsed in 11 AL patients with low expression level of cyclin G2 (90.9%); and 7 relapsed in 17 AL patients with high expression (41.2%), and there was significant difference (P < 0.05). In conclusion, the expression of cyclin G2 in AL patients was higher than that in normal control, the abnormal expression of cyclin G2 might be a prognostic marker of CR in AL patients.

[Effect of cyclin G1 antisense oligodeoxynucleotides (ASON) on the growth of HL-60 cells in nude mice].

OBJECTIVE: To study the inhibition effect of cyclin G(1) antisense oligodeoxynucleotides (ASON) on the growth of HL-60 cells in nude mice. METHODS: (1) Nude mice were divided into control group, sense oligodeoxynucleotides (SON) group and ASON group. After (60)Co radiation, with HL-60 cells SON group and ASON group were subcutaneously innoculated; (2) The weight and volume of tumors were continually measured; (3) The morphology of tumor cells was observed by microscope; (4) The protein and mRNA expression levels of cyclin G(1) were determined by flow cytometry (FCM) and reverse transcription polymerase chain reaction (RT-PCR); (5) The cell apoptosis was detected by electron microscopy and FCM. RESULTS: (1) The inhibition rate of tumor in ASON group was 69.4%. In ASON group, the wight and volume of tumor were significantly lower than those in SON group and control group. (2) The HL-60 cells in ASON group showed morphologically smaller nuclei, less mitosis, less heteromorphosis and apoptosis. CONCLUSION: The cyclin G(1) ASON can inhibit the growth of HL-60 cells in nude mice and induce apoptosis.

[Proliferation regulation effect of cyclin G1 antisense oligodeoxy-nucleotides with liposomal transfection on HL-60 cell].

To investigate the effect of cyclin G1 antisense oligodeoxynucleotide (ASON) with liposomal transfection on mediating proliferation of HL-60 cell, the cyclin G1 ASON with liposomal transfection was used in vitro in co-culture with HL-60 cell, the protein and mRNA expression levels of cyclin G1 were measured by immunocytochemistry assay and RT-PCR. The cell apoptosis was detected by electron microscopy, in situ cell apoptosis detection kit (POD), DNA gel electrophoresis and flow cytometry (FCM). The results showed that in the cyclin G1 ASON group the protein and mRNA expression of cyclin G1 were significantly inhibited as compared with sense oligodeoxynucleotide (SON) group and blank group. When the ASON concentration increased, the proliferation ratio of HL-60 cell and CFU of HL-60 were also significantly inhibited. There was apoptosis of HL-60 cell. In conclusion, cyclin G1 ASON can specifically inhibit its protein and mRNA expression levels as well as the HL-60 cell proliferations and can accelerate the apoptosis of leukemia cells with concentration-dependent effect of ASON.