Coculture with mesenchymal stem cells facilitates the proliferation of hematopoietic stem cells under different coculture modes

Wang Shu-yue; Lin Fan-li; Qian Yi; Chen Xiao-qing; Liu Yang; Li Shu-tan; Cheng Yan; Xiong Hao; Huang Chun-lan

doi:10.3969/j.issn.2095-4344.0508

Abstract：BACKGROUND: Although a large number of related studies have been carried out, there is still a lack of practical methods to amplify hematopoietic stem cells(HSCs)in vitro.Mesenchymal stem cells(MSCs)secrete a variety of cytokines that promote the HSCs proliferation and inhibit their differentiation. These cytokines play an important role in maintaining the hematopoietic microenvironment and regulating HSCs function. OBJECTIVE:To investigate the effect of bone marrow MSCs on the proliferation of HSCs in vitro under different coculture modes. METHODS:Mesenchymal stem cells from the bone marrow of C57BL/6 mice were cultured in vitro using the whole bone marrow adherent culture. CD117+cells (HSCs) were sorted from passage 3 cells by using miniMACS magnetic beads sorting. Then, CD117+cells were co-cultured with MSCs under different coculture models, including single culture of HSCs (control group), Transwell coculture (upper chamber, HSCs; lower chamber, MSCs) and two-dimensional contact coculture (coculturing HSCs and MSCs in 24-well plates). The morphology of HSCs was observed under phase contrast microscope and fluorescence microscope, and the number of active cells of HSCs was counted at 1, 3, 5, and 7 days after coculture. RESULTS AND CONCLUSION: During the coculture of 1-7 days, the number of HSCs in the two groups was increased with culture time (P <0.05). After 3 days of coculture, HSCs in each group was grown into the logarithmic growth phase, and morphological changes in some HSCs were detected at 5 days of coculture. At 7 days of coculture, the viabilities of HSCs in different culture models were ranked as follows: single culture model < Transwell coculture model < two-dimensional contact coculture model (P < 0.05). These findings suggest that MSCs can effectively promote the proliferation of HSCs in vitro,and the promotion effect is increased under contact coculture conditions.