PKH26 combined with Hoechst 33258 to trace the iRhom2 gene and its mutant proteins of Uncv mice in Vero cells / 中国比较医学杂志

Objective To determine the localization of iRhom2 and its mutant proteins of Uncv mice in Vero cells by PKH26 combined with Hoechst 33258 staining.Methods The cell membrane was stained with PKH26, and the nuclei were stained with Hoechst 33258 dye, and observed by laser scanning confocal microscopy.Results It was found that wild iRhom2 was distributed in the cytoplasm, and its iRhom2mut was present both in cytoplasm and cell nuclei.Conclusions The results of our study suggest that a deletion in N-terminal of iRhom2 affects its subcellular localization.

Detection of Specific DNA Sequence with a Non-labeled Molecular Beacon and a Nucleic Acid Dye Hoechst 33258 / 分析化学

A highly sensitive and selective method for specific DNA sequence detection is developed using a non-labeled molecular beacon (MB) and a nucleic acid dye Hoechst 33258. It is demonstrated by a specific DNA sequence of wild-type HBV as a model system. In this strategy, the stem of MB is completely designed as C/G base pairs. In the absence of target DNA, the interaction between Hoechst 33258 and the MBs is very weak,and the fluorescence signals of Hoechst 33258 is very low. In the presence of target DNA, the MBs hybridize with the target DNA and form double-stranded structure. Hoechst 33258 binds to dsDNA, and the fluorescence intensity is significantly enhanced. Under the optimum conditions, the fluorescence intensity of Hoechst 33258 exhibits good linear dependence on target DNA concentration in the range of 2 × 10-10-2 × 10-8 mol/L. The fitted regression equation is △I=3. 3439C(10-10 mol/L) ﹢18. 6949(R2=0. 9982) with a correlation coefficient of 0. 9982 (R2), and the detection limit is 9 × 10-11 mol/L (3σ). The proposed method has good precision, simple operation, fast detection speed, low detection limit, high accuracy and high sensitivity.

Radiomodulation by Hoechst 33258 against radiation- induced damage in murine splenocytes.

In this study modulatory effect of Hoechst 33258 on radiation induced membrane related signaling events which ultimately leads to apoptosis has been investigated. Splenocytes from swiss albino mice were irradiated in air at room temperature in a gamma chamber (240 TBq 60Co Model 4000 A) at the dose-rate of 0.052 Gys-1. Membrane lipid peroxidation, fluidity, specific activities of antioxidant enzymes, levels of nitric oxide, glutathione and apoptosis in presence and absence of different concentrations of Hoechst 33258 has been assayed. DNA binding activity of nuclear factor kappa B and activator protein–1 was also assayed by electrophoretic mobility shift assay. Modulatory effect of Hoechst 33258 was examined at 3 and 5 Gy using different concentrations (10, 20 and 30 µM). Hoechst 33258 was found to inhibit radiation induced peroxidative damage and fluidity and lowered the level of nitric oxide and apoptosis - as evident by DNA ladder assay and FACS, indicating free radicals scavenging potential. Dot plot diagramme clearly showed that 30 µM Hoechst 33258 caused 14% and 19% decrease in apoptotic cells at 3 Gy and 5 Gy of radiation respectively (compared to irradiated control group). Further DNA binding activity of nuclear factor kappa B and activator protein–1 was also inhibited but the antioxidant potential of the cells was enhanced. These findings support that Hoechst 33258 protects the cell from undergoing apoptosis. Hoechst 33258 may have interacted and has an ability to protect splenocytes against radiation induced apoptosis through modulation of membrane-related signaling events and antioxidant status.

Cell cycle and DNA content of mitotic cells in brain ganglia of Drosophila larvae.

The programmes of replication of hetero- and euchromatin regions, mitotic cell cycle and the DNA content in metaphases in brain ganglia from late third instar larvae of Drosophila melanogaster (wild type and a tumour bearing mutant, 1(2)gl, strain) and of Drosophila nasuta were examined by autoradiography of [3H]thymidine labelled (continuous or pulse) cells and by cytophotometry, respectively. Brain ganglia labelled continuously with [3H]thymidine for 24 h in vitro showed a significantly high proportion of cells with incorporation of radioactivity restricted to heterochromatin only. Pulse labelling of brain ganglia from larvae of Drosophila melanogaster and Drosophila nasuta followed by chase for different time intervals showed that (i) the frequency of labelled metaphases was more than 50% within 15 to 30 min of chase and remained higher than 50% in nearly all the chase samples till 24 h, (ii) euchromatin labelled metaphases appeared with a low frequency within 1 to 4 h chase period but the heterochromatin labelled metaphases continued to be more common in the later chase samples also, (iii) single chromatid labelled second cycle metaphases were seen within 1 to 4 h after the pulse, but their frequency did not increase in the later samples. Cytophotometry of feulgen-DNA and Hoechst 33258 stained metaphases in late third instar larval brain ganglia revealed a greater variation in the DNA content of individual metaphases, although the means were close to the expected 4 C content. It appears that in relation to the known asymmetric cell divisions of neuroblast and other neural cells, the mitotically active cells in brain ganglia comprise a heterogenous population with widely varying lengths of the different phases of cell cycle; some of them may not cycle regularly and may possibly have a discontinuous S-phase.

Protective effects of ganoderma lucidum polysaccharides peptide on human umbilical vein endothelial cells injury by reactive oxygen species / 中国药理学通报

Aim To study the protective effects of Ganoderma lucidum polysaccharides peptide(GLPP)on the human umbilical vein endothelial cells(HUVECs)injured by reactive oxygen species(ROS),derived from tert-butylhydroperoxide(t-BOOH).Methods Vascular endothelial cells were obtained from infant umbilical cord for primary cultivation,identified by endothelial cell adhesion molecule-1(CD31)by fluorescence microscope.HUVECs were injured by ROS,derived from t-BOOH.The survival rate of cells was measured by Cell Counting Kit-8 assay.Hoechst 33258 nucleus staining was used to observe the early apoptosis injury by ROS.And the activation of Caspase-3 was detected by spectrophotometry.Electron microscopy was used to show the morphological changes in HUVECs.Results GLPP(6.125,12.5,25,50,100 mg?L-1)could inhibit the apoptosis of HUVECs by ROS.The survival rate of HUVECs was increased by GLPP and the percentage of cell apoptosis was decreased by it too.GLPP decreased the activation of Caspase-3 of HUVECs up-regulated by ROS.Electron microscope showed that the organelle such as mitochondria injury by ROS could be relieved by GLPP.Conclusion GLPP can prevent human umbilical vein endothelial cells from oxidative injury.