Comparison Of Myocardium Differentiation Capacity Between Human Bone Marrow And Placental Decidua Basalis Derived Mesenchymal Stem Cells In The Three-dimensional Culture System Set With Small Intestinal Submucosa

Objective: To compare myocardium differentiation capacity between human bone marrow and placental decidua basalis derived mesenchymal stem cells in the three-dimensional culture system set with small intestinal submucosa and to provide theoretical rationales for selecting myocardial tissue engineering seed cells. Methods: Mesenchymal stem cells(MSCs) were extracted from human bone marrow and human pacental decidua basalis tissues and then amplifying cultured in vitro. Cellsurface markers in bone marrow mesenchymal stem cells(BM-MSCs)and pacental decidua basalis mesenchymal stem cells(PDB-MSCs)were examined using flow cytometry. In addition, BM-MSCs and PDB-MSCs were differentiated into osteoblasts, adipocytes and chondrocytes to identify their pluripotential differentiation ability. Afer BM-MSCs and PDB-MSCs have been cultured in SIS respectively for 5 days the cells-scaffold compounds were formed and then the cells-scaffold compounds were randomly divided into 4 groups: BM-MSCs-SIS being induced differentiation group, BM-MSCs-SIS being not induced differentiation group, PDB-MSCs-SIS being induced differentiation group and PDB-MSCs-SIS being not induced differentiation group. Aftertreated with 5-aza for 24 h, the cells-scaffold compounds in induced groups continued to be cultured with complete culture medium for 4 weeks. While in the not induced groups, 5-aza was replaced by phosphate buffer saline(PBS) and other operations were the same as induced differentiation groups. After the induced differentiation process was over, morphological changes of BM-MSCs and PDB-MSCs in SIS were observed using scanning electron microscope(SEM); Differentiation of BM-MSCs and PDB-MSCs into cardiomyocyte-like cells was identified using anti human c Tn I immunofluorescence assay; Cell differentiation rates of BM-MSCs and PDB-MSCs were calculated using flow cytometry; Expression of transcription factors which emerged in the early stage of heart development(Nkx2.5 and GATA-4) were detected using RT-PCR assay; Expression of specific proteins which emerged in the late stage of cardiomyogenic differentiation(c Tn I and CX43) were also detected using Western Blot assay. Meanwhile, cells at the edge of SIS were observed under inverted microscope to acknowledge whether these cells could beat spontaneously. Results: MSCs derived from human bone marrow and human pacental decidua basalis tissues were positive for CD90, CD44, CD73 and CD105 and negative for CD45, CD34, CD11 b, CD19 and HLA-DR. What is more, BM-MSCs and PDB-MSCs were differentiated into osteoblasts, adipocytes and chondrocytes. After treated with 5-aza for 24 h and continued to be cultured with normal complete culture medium for 4 weeks BM-MSCs and PDB-MSCs shew good biocompatibility with SIS and a part of these cellsshowed starlike or rod shaped morphology which were quite similar to the morphology of cardiomyocytes. Anti human immunofluoresce assay illustrated BM-MSCs and PDB-MSCs have differentiated into cardiomyocyte-like cells. However, there was no significant difference in the differentiation rate between BM-MSCs and PDB-MSCs. After induced differentiation, the two kind of cells expressed transcription factors which emerged in the early stage of heart development(Nkx2.5 and GATA-4) and specific proteins which emerged in the late stage of cardiomyogenic differentiation(c Tn I and CX43). The two kind of cells expressed transcription factors which emerged in the early stage of heart development at the same level. However, compared with BM-MSCs, PDB-MSCs expressed much more specific proteins proteins which emerged in the late stage of cardiomyogenic differentiation. Meanwhile, there were no cardiomyocyte-like cells which generated from BM-MSCs or PDB-MSCs could beat spontaneously. Conclusion: SIS is an ideal bio-scaffold material for cardiac tissue engineering, it has good biocompatibility with BM-MSCs and PDB-MSCs. Although cardiomyocyte-like cells which generated from BM-MSCs and PDB-MSCs were not fully matured, comparing with BM-MSCs, cardiomyocyte-like cells generated from PDB-MSCs were more mature. Thus, PDB-MSCs may be more fit to to seed cells for myocardial tissue engineering.