Objective To explore the effect of stroma cell-derived factor receptor CXCR4 on the homing of the hematopoietic stem/progenitor cells in utero transplantation. Methods CD34~+ cells were collected by Ficoil density gradient centrifugation and MiniMACS and then stimulated for 48 h by SCF and IL-6 cytokines prior to transplantation. CD184(CXCR4) expressions and transmigrate rates of the CD34~+ cells were analysed by flow cytometer. Cells pre-treated with different treatment were transplanted into the abdominal cavity of the fetal BALB/c mouse in the pregnant days 13～14. Human CD45 cells as the marker of graft were detected by flow cytometry after 1 month the fetus born. Results Expression changes of CD184 on CD34~+ cells were from 9. 58%±1. 56% to 19. 32%±3. 64% after SCF and IL-6 stimulation. The CD34~+/CXCR4~(high) cells exhibited significant increases in SDF-1 mediated chemotaxis compared with the CD34~+/CXCR4~(low) cells. Transmigration of CD34~+ /CXCR4~(high) was inhibited by pretreatment with an-tiCXCR4mAb and PTX. The positive rates of human CD45 cells detected in the fetal mouse were significantly higher in the SCF and IL-6 pretreatment group. This effects were significantly abrogated after the addition of antiCXCR4mAb or PTX. Conclusion Up-regulation of CXCR4 expression may be useful for improving hematopoietic stem/progenitor cells homing in utero transplantation. This homing process is mediated and depends on the CXCR4 receptors. The signal transduction is mediated by PTX-sensitive Gi protein.

Objective To explore the effect of stroma cell-derived factor receptor CXCR4 on the homing of the hematopoietic stem/progenitor cells in utero transplantation. Methods CD34+ cells were collected by Ficoll density gradient centrifugation and MiniMACS and then stimulated for 48 h by SCF and IL-6 cytokines prior to transplantation. CD184(CXCR4) expressions and transmigrate rates of the CD34+ cells were analysed by flow cytometer. Cells pretreated with different treatment were transplanted into the abdominal cavity of the fetal BALB/c mouse in the pregnant days 13～14. Human CD45 cells as the marker of graft were detected by flow cytometry after 1 month the fetus born. Results Expression changes of CD184 on CD34+ cells were from 9.58%?1.56% to 19.32%?3.64% after SCF and IL-6 stimulation. The CD34+/CXCR4high cells exhibited significant increases in SDF-1 mediated chemotaxis compared with the CD34+/CXCR4low cells. Transmigration of CD34+/CXCR4high was inhibited by pretreatment with antiCXCR4mAb and PTX. The positive rates of human CD45 cells detected in the fetal mouse were significantly higher in the SCF and IL-6 pretreatment group. This effects were significantly abrogated after the addition of antiCXCR4mAbor PTX. Conclusion Up-regulation of CXCR4 expression may be useful for improving hematopoietic stem/progenitor cells homing in utero transplantation. This homing process is mediated and depends on the CXCR4 receptors. The signal transduction is mediated by PTX-sensitive Gi protein.

AIM: To investigate the use of therapy ultrasound to enhance nonviral gene delivery. METHODS: Endothelial cells (EC) and vascular smooth muscle cells (VSMC) were cultured in 6-well plates. Plasmid (pcDNA3.1/His/LacZ) with or without microbubbles at the different concentrations was transfected into the cells with the use of ultrasound for 1 min at 2 MHz, 1.8 mechanical index (MI). Additional controls included ultrasound alone, microbubble alone and microbubble plus plasmid. The rate of blue cells and the activities of ?-Gal were measured. In addition, cell viability was detected with different time from 1 to 30 min of ultrasound irradiation and the different concentrations of microbubbles. RESULTS: In the group of ultrasound with microbubble, the rate of blue cells and activity of ?-Gal markedly increased by 60% and 9-fold, respectively. Microbubbles at concentration of 10% led to the highest transfection effect. Ultrasoud exposure at 1 to 30 minute had no cell toxic effects, while microbubbles at the concentration of 50% had significant effect on cell survival. CONCLUSIONS: Albumin-coated microbubbles markedly enhance gene delivery by therapeutic ultrasound-mediated microbubble destruction, which can be used as a safe and practicality vectors in gene therapy.

Exposure to ionizing radiation intervenes in genomic stability and gene expression,resulting in the disruption of normal metabolic processes in cells and organs by causing complex biolog-ical responses.Altered genomic variations,gene expression and metabolite concentrations in blood or tissue samples reflect systemic radiation damage.With the application of new techniques and exten-sive study on the mechanisms for ionizing radiation damage,related indicators such as chromosomal variation,gene expression,lipid and metabolism are being recognized and promise to be the markers for early diagnosis and prognosis of radiation exposure.Therefore,this article reviews recent progress in and potential applications of biomarkers related to ionizing radiation injury.