In vitro differentiation of umbilical cord blood CD34+ cells into mature megakaryocytes and generation of plateletss
- VernacularTitle:脐血CD34+细胞体外诱导分化为成熟巨核细胞及产出血小板
- Author:
Xin LI
;
Fangping CHEN
;
Jing LIU
;
Xinhua WU
;
Tiebin JIANG
;
Xueyuan TANG
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2009;13(10):1976-1980
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: There still was not any report about inducing stem cells into matured cells to form products in vitro.OBJECTIVE: To induce CD34+ cells of umbilical cord blood to differentiate into mature megakaryocytes, and to investigate the mechanism of production of platelets.DESIGN, TIME AND SETTING: This cytology in vitro study was conducted at the Central Laboratory of Xiangya Hospital and Xiangya Third Hospital from 2004 to 2006. MATERIALS: Umbilical cord was collected from healthy full-term pregnant puerperants at the Xiangya Hospital.METHODS: The CD34+ cells were isolated from umbilical cord blood by magnetic activated cell sorting (MACS) and then cultured in 24-well culture plate at 5x107/L in StemPro-34 serum-free medium, supplemented with L-glutamine, saturated human transferrin, CaCl2, insulin, deionized bovine serum albumin and recombinant human thrombopoietin at 37℃, under 0.05 volume fraction CO2 saturated humidity to be differentiated into megakaryocytes for 14-21 days. Cell medium was absorbed, and centrifuged to obtain supernatant. Samples were centrifuged again, and then supernatant was removed. The remaining was platelet-like particles in cell culture plate. Platelet was isolated from normal platelet-rich plasma.MAIN OUTCOME MEASURES: The following parameters were measured: morphological changes in cultured cells and platelet-like particles in supematant; results of immunohistochemistry; observation results under a microscope; platelet aggregation; CD41 expression.RESULTS: At day 10, silk-like substances were found in megakaryocyte culture medium, with the presence of platelet-sized particles. The production of platelet-sized particles reached a peal at day 16. Cultured cells were strongly positively for platelet-specific antigen GP Ⅱb Ⅲa. Under the optical microscope, mature megakaryocytes were detected, with the presence of some immature megakaryocytes, and platelet-sized particles were found surrounding megakaryocytes. Under the electron microscope, a majority of mature megakaryocytes and a few apoptotic megakaryocytes were detected, and platelet-sized particles in the supernatant had the same size and structure with the platelet in the platelet-rich plasma. Some platelet surfaces were smooth or irregular. Platelet-sized particles in the supematant aggregated in response to thrombin as platelets in normal platelet-rich plasma. Flow cytometry demonstrated that the cultured platelets had the same high expression rate of CD41 as the platelets from platelet rich plasma.CONCLUSION: Umbilical cord blood CD34+ cells can be induced to differentiate into pudfied and mature megakaryocytes and platelets in vitro.
