Peptide-RNA complexation-induced fluorescence"turn on"displacement assay for the recognition of small ligands targeting HIV-1 RNA / 药物分析学报

The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluores-cence indicator displacement assays have been used to identify ligands that can inhibit the Rev-RRE interaction;however,the small fluorescence indicators cannot fully replace the Rev peptide or protein.As a result,a single rhodamine B labeled Rev(RB-Rev)model peptide was utilized in this study to develop a direct and efficient Rev-RRE inhibitor screening model.Due to photon-induced electron transfer quenching of the tryptophan residue on the RB fluorophore,the fluorescence of RB in Rev was weakened and could be dramatically reactivated by interaction with RRE RNA in ammonium acetate buffer(approximately six times).The interaction could reduce the electron transfer between tryptophan and RB,and RRE could also increase RB fluorescence.The inhibitor screening model was evaluated using three known positive Rev-RRE inhibitors,namely,proflavin,6-chloro-9-[3-(2-chloroethylamino)pro-pylamino]-2-methoxyacridine(ICR 191),and neomycin,as well as a negative drug,arginine.With the addition of the positive drugs,the fluorescence of the Rev-RRE decreased,indicating the displacement of RB-Rev.This was confirmed using atomic force microscopy(AFM)and the fluorescence was essentially unaffected by the addition of arginine.The results demonstrated that RB-Rev can be used as a fluorescent probe for recognizing small ligands that target RRE RNA.The Rev-RRE inhibitor screening model offers a novel approach to evaluating and identifying long-acting Rev inhibitors.

The ameliorate effect of anthocyanin onMouse testis damage / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of Anthocyanin (Ay) on Cadmium-Induced Mouse testis Damage.</p><p><b>METHODS</b>Mouse testis damage model were constructed and testis malonaldehyde (MDA) and protein carbonxyl content (PCO), as well as catalase (CAT) and superoxide dismutase (SOD) were determined.</p><p><b>RESULTS</b>The intoxication of cadmium can cause the increase of MDA and PCO content in mouse testis (P < 0.05), however, the activities of SOD and CAT were altered (P < 0.01).</p><p><b>CONCLUSION</b>Ay have the strong potent to scavenge free radicals, owing to its special chemical structures, and act as a protector to inhibit the oxidative stress induced by cadmium.</p>

Effects of hydrogen sulfide on pulmonary surfactant in rats with acute lung injury induced by lipopolysccharide / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the changes of pulmonary surfactant (PS) in rats with acute lung injury(ALI) induced by lipopolysaccharide (LPS) and to explore the effects of hydrogen sulfide (H2S) on PS.</p><p><b>METHODS</b>Fourty- eight male rats were randomly divided into six groups (n = 8). They were control group, LPS group, LPS+ NaHS low, middle, high dose groups and LPS+ PPG group. Saline was administrated in Control group. LPS was administrated in LPS group. In LPS + NaHS low, middle, high dose groups or LPS + PPG group, sodium hydrosulfide (NaHS) of different doses or DL-propargylglycine (PPG) were respectively administrated when the rats were administrated of LPS after 3 hours. All the rats were killed at 6 hours after administration of Saline or LPS. The morphological changes of alveolar epithelial type II cells (AEC-II) were respectively observed by transmission electron microscopes. The content of H2S in plasma and activity of cystathionine-gamma-lyase (CSE) in lung tissues were respectively detected. The contents of total protein (TP) and total phospholipids (TPL) in bronchoalveolar lavage fluid (BLAF) were respectively measured. The pulmonary surfactant protein A (SP-A), surfactant protein B (SP-B) and surfactant protein-C (SP-C) mRNA expressions in lung tissues were analysed.</p><p><b>RESULTS</b>(1) Compared with control group, the content of H2S in plasma, activity of CSE, content of TPL, and SP-A, SP-B and SP-C mRNA expressions were respectively decreased in LPS group (P < 0.05 or P < 0.01). But the content of TP was increased in LPS group (P < 0.01); (2) Compared with LPS group, the content of H2S, activity of CSE and SP-A mRNA expression were significantly increased in LPS + NaHS low, middle and high dose groups (P < 0.05). The SP-B mRNA expression and content of TPL were significantly increased in LPS + NaHS Middle and High dose groups (P < 0.05). The content of TP was decreased in LPS + NaHS High dose group (P < 0.05). The SP-C mRNA expression was not altered in LPS+ NaHS low, middle and high dose groups (P > 0.05); (3) Compared with LPS group, the content of H2S, activity of CSE, content of TPL, and SP-A, SP-B and SP-C mRNA expressions were respectively decreased, but content of TP was increased in LPS + PPG group (P < 0.05).</p><p><b>CONCUSION</b>The decrease of PS is the important physiopathologic process of ALI induced by LPS. Exogenously applied H2S could attenuate the process of ALI that possibly because H2S could adjust the compose and secretion of PS.</p>

Discrimination of anticancer agent action loci at G(2) and M phases by flow cytometry and confocal microscopic imaging / 中国实验血液学杂志

This study was purposed to evaluate a method to discriminate the action loci of anticancer agents in G(2) and M phases of cell cycle. The meta-amsacrine (m-AMSA) and vinblastine (VBL), already known as G(2) and M phase arrest agent respectively, were used to induce the arrest of MOLT-4 cells at G(2) and M phases, the change of DNA content was detected by flow cytometry, the morphology of arrested cells was observed by confocal microscopy so as to find the arrest efficacy difference of 2 anticancer agents. As a result, the flow cytometric detection showed that the arrested MOLT-4 cells displayed the raise of peaks in G(2) and M phases, but flow cytometric detection alone can not discriminate the difference between them. The observation with confocal microscopy showed that the MOLT-4 cells arrested by m-AMSA displayed the morphologic features in G(2) phase, while the MOLT-4 cells arrested by VBL displayed the morphologic features in M phase. This observation with confocal microscopy is helpful to discriminate the difference between them. In conclusion, the combination of flow cytometry with confocal microscopy is one of the effective methods to discriminate the kind of G(2) or M phase arresting agent of anticancer drugs.