Changes in expressions of sRNA SpR19 and its potential target GroEL in Streptococcus mutans strains with different cariogenicity cultured under different pH conditions / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in the expression level of sRNA SpR19 and its potential target protein GroEL in clinical isolates of Streptococcus mutans with different cariogenicity exposed to different pH conditions and explore the possibility of using these molecules as biomarkers for assessing the cariogenicity of the bacteria.</p><p><b>METHODS</b>The total RNAs were extracted from the clinical isolates of Streptococcus mutans with high (strain 17) and low cariogenicity (strain 5) for high-throughput sequencing for profiling of the differentially expressed sRNAs. The candidate sRNA, SpR19, was selected for further study on the basis of bioinformatics analysis considering the role of its potential target in the cariogenic process. The differential expression levels of SpR19 in the strains exposed to both pH5.5 and pH7 culture conditions were verified by quantitative real-time PCR. The expression of the potential target of SpR19, GroEL, was also investigated at both the protein and mRNA level using Western blotting and quantitative real-time PCR.</p><p><b>RESULTS</b>Bioinformatic analysis suggested multiple potential target sites of SpR19 both in GroEL mRNA and in the upstream and downstream inter-genic regions. Under different pH conditions, the highly cariogenic strain 17 expressed consistently low levels of SpR19 as compared with the strain 5 with a low cariogenicity; GroEL showed a reverse expression pattern in the 2 strains. An inverse correlation was found between the expressions of SpR19 and GroEL.</p><p><b>CONCLUSION</b>The highly cariogenic strain 17 expressed low levels of SpR19 and high levels of GroEL in both acidic and neutral culture conditions. SpR19 may negatively regulate the cariogenicity of Streptococcus mutants by targeting at GroEL.</p>

Advances in research on intronic miRNAs feedback regulation of their host genes / 军事医学科学院院刊

miRNAs were discovered less than a decade ago, and have emerged as important regulators of gene expression in mammals. A large number of miRNAs have been identified to be located within the intronic regions of protein-encoding genes(host genes) and called intronic miRNAs. The intronic miRNAs may play a key role in regulating the expression and function of their host genes due to the fact that most of them are co-expressed with the host genes. In this paper, the recent advances on the research on potential relationship between intronic miRNAs and their host genes are reviewed.

Expression, purification of Staphylococcus aureus Efb protein and preparation of its functional antibody / 军事医学科学院院刊

Objective:To clone and express the Staphylococcus aureus Efb(extracellular fibrinogen-binding protein) protein in Escherichia coli, to purify the expression product and prepare its functional antibody and to detect the functions of Efb protein for further studies on S.aureus infection.Methods: Efb gene was amplified by PCR using S.aureus NCTC-8325 genome DNA as template and cloned into the recombinant expression vectors pET28a. E.coli BL21(DE3) with the plasmid was induced with IPTG for protein production. The protein was purified by Ni~(2+) affinity chromatography. The function of Efb protein was determined by complement activity assay and inhibition ELISA.The polyclonal antibodies were prepared by immunizing the animals. Results: The purified recombinant Efb was obtained, which could inhibit the CH50 and AH50 effectively. The functional poly-antibodies of Efb were prepared.Conclusion:Efb could inhibit the classical pathway and alternative pathway of complement activation, and the antibodies against to Efb could block the inhibition of the classical pathway of complement activation induced by Efb.

Transfer RNAs inhibit the growth of L929 cells in vitro / 中国应用生理学杂志

<p><b>AIM</b>To explore the effects of tRNA on the growth of mammalian cells.</p><p><b>METHODS</b>L929, NIH3T3, MCF-7 and PC12 cells were seeded in 96 well culture plate individually, and incubated at 37 degrees C in 5% CO2 for 4 h, the tRNAs from different species were added to the culture media individually. After certain time of incubation, the viability of the cells was evaluated by the MTT methods. Sub-confluent L929 cells were incubated with 200 microg/ml ytRNA for different times, then the cells were pooled and analyzed with flow cytometry assay.</p><p><b>RESULTS</b>tRNA specifically inhibited the growth of L929 cells in a dose-dependent manner. The sizes of tRNA-treated cells showed larger sizes and longer processes than those of untreated cells. Flow cytometric analysis further showed that most of tRNA-treated cells were arrested in S phase of the cell cycle.</p><p><b>CONCLUSION</b>The cell growth inhibitory effects of tRNAs were caused mainly by their degraded fragments. The results suggested that tRNA or its degraded fragments might play important roles in regulation of cell proliferation.</p>

Preliminary study on change of serum proteome in noxious heat blood stasis syndrome treated by radix Paeoniae rubra / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effect of red peony root (RPR) on serum proteome in rat suffering from noxious heat with blood stasis Syndrome (NH-BS).</p><p><b>METHODS</b>The differences of serum proteome among rats in four groups, treated with lipopolysaccharide (LPS), RPR, LPS + RPR and saline respectively, were analyzed by bi-dimensional electrophoresis (2DE) assay. LPS was administered by intravenous injection and RPR by oral intake.</p><p><b>RESULTS</b>(1) Serum of rats with LPS induced NH-BS showed significant changes in volume of serum protein (xPr) in 13 points on 2DE collagen, the volume of xPr 16 and 19 were significantly lower, volume of xPr 1, 2, 3, 4, 6, 7, 8, 9, 11, 12 and 23 were significantly higher respectively, as compared with those in the normal control group. (2) After being treated with RPR, the increased volume of xPr 1, 2, 3, 4 and 9 significantly decreased, and the decreased xPr 16 significantly increased, with xPr 2, 3 restored to normal level but the xPr16 still lower and xPr 1, 4, 9 higher than those in the normal group. RPR showed interaction with LPS on xPr 1, 3, 9, and 16. (3) For xPr 19, the interaction of RPR with LPS might be synergistic. (4) In the group treated with RPR, volumes of xPr 13 and 14 were significantly higher and those of 15, 17 were significantly lower than those in the normal group respectively, but the similar changes didn't found in the LPS group.</p><p><b>CONCLUSION</b>The molecular basis of therapeutic effect of RPR on NH-BS might be through the regulation of xPr 1, 2, 3, 4, 9 and 16.</p>

Study on serum proteome of rat endotoxemia treated by figwort root / 中国中药杂志

<p><b>OBJECTIVE</b>To study the serum proteome of rat endotoxemia treated by figwort root (FR).</p><p><b>METHOD</b>The differences of serum proteome among rats treated with lipopolysaccharide (LPS), FR, LPS + FR and saline respectively were analyzed by two-dimensional electrophoresis (2DE) assay.</p><p><b>RESULT</b>The volumes of sixteen serum proteins (xPr) in LPS induced-endotoxemia group were greatly changed compared with those of the control group. Among them, the volumes of xPr 16, 19 were significantly decreased, and the volumes of xPr 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 18, 23 were significantly increased. When treated with FR, the volumes of xPr 1, 6, 7, 8, 9, 11, 12, 14, 18, 23 were significantly decreased, and the volumes of xPr 8, 9, 11, 12, 23, 14 were back to normal level. Two factors statistic analysis showed that FR had interaction with LPS for xPr 1, 5, 8, 10, 11, 12, 18, 19, 20, 21, 22, and FR might be the functional antagonist of LPS. We also observed that the volumes of xPr 10, 13, 15, 20, 21, 22 were found to change significantly only in FR treated group but not in LPS treated group or control group. Interestingly, the volume of xPr 13, 20, 21, 22 were increased and the volume of xPr 10, 15 were decreased.</p><p><b>CONCLUSION</b>The molecular basis of therapeutic effect of FR on endotoxemia might be through the regulation of xPr 1, 6, 7, 8, 9, 11, 12, 14, 18, 23. We can use proteomic techniques to study the molecular mechanisms of diseases treated by functional Chinese herbs and the combination of different herbs is necessary for the treatment of endotoxemia, as FR can not regulated all the changed proteins induced by LPS.</p>