HOXB6-mRNA and its gene expression in the differentiation process of human cytomegalovirus-infected hematopoietic stem progenitor cells into granulocyte and erythrocyte progenitor cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Is the inhibition of the hematopoietic stem progenitor cell (HSPC) proliferation and differentiation after human cytomegalovirus (HCMV) infection associated with abnormal expression of infected cell proliferated gene?OBJECTIVE: To observe the HOXB6-mRNA expression in the process of proliferation and differentiation of HCMV-infected HSPC into colony-forming unit granulocyte-macrophage (CFU-GM) and colony-forming unit erythroid (CFU-E).DESIGN: A controlled observation.SETTING: Laboratory for Molecular Biology, Affiliated Hospital of Luzhou Medical College, Lanzhou, Gansu Province, China.MATERIALS All cord blood (CB) specimens were provided by the Obstetrics Department of Affiliated Hospital of Luzhon Medical College. They were collected from the umbilical vein of normal term neonates delivered spontaneously. All neonate mothers were healthy and HBS-Ag-negative. HCMV-IgM antibody revealed by routine ELUSA and HCMV-DNA checked by PCR were undetectable. Written informed consent for the laboratory measurements was obtained from each neonate mother, and the protocol was approved by the hospital's Ethics Committee. HCMV-AD169 strains were obtained from the Institute of Virology, Chinese Academy of Preventive Medicine. All-trans retinoic acid (ATRA, lot No. 20010126) was provided by Chongqing Huapont Pharm. Co., Ltd., China.METHODS: This study was performed at the Laboratory of Molecular Biology (state-level), Affiliated Hospital of Luzhou Medical College of Luzhou Medical College from April 2006 to April 2007. Cord blood mononuclear cells were separated for HSPC culture. According to different interventions, the study consisted of 4 groups. Control group no HCMV virus solution was added and equal volume of culture medium was added instead. HCMV group 105 PFU/mL HCMV-AD169 virus solution was added to the culture system. ATRA group ATRA was added into the cultivation system at the final concentration of 60 μ mol/L. HCMV+ATRA group ATRA was added into the HCMV group, and its final concentration was also 60 μ mol/L.MAIN OUTCOME MEASURES: In each group, cells were harvested on days 3,7 and 12. HOXB6 mRNA expression levels in CFU-GM and CFU-E were detected by real-time fluorescent-based quantification PCR.RESULTS: In the control group, both CFU-E and CFU-GM expressed HOXB6-mRNA. The HOXB6 mRNA expression was increased as a function of time. The HOXB6-mRNA expressed by CFU-E reached its peak level on day 12, while that expressed by CFU-GM reached its peak level on day 7. Compared to control group, the expression levels of CFU-E and CFU-GM HOXB6-mRNA genes in normal cord blood were significantly lower in the HCMV group (P＜0.05)and significantly higher in the ATRA group (P＜0.05) at each time point after HCMV infection. Furthermore, the expression levels were significantly higher in the ATRA+HCMV group than in the HCMV group at each time point(P＜0.05-0.01).CONCLUSION: HOXB6-mRNA expression is stable and lasting in the proliferation and differentiation of HSPC into CFU-GM and CFU-E. HCMV could down regulate HOXB6 gene expression, and ATRA could up regulate HOXB6 gene expression.