title: Variations in the ratios of co-cultured mesenchymal stem cells and chondrocytes regulate the expression of cartilaginous and osseous phenotype in alginate constructs.
abstract: As mesenchymal stem cells (MSCs) are capable of self-renewal and multilineage differentiation, the feasibility and efficacy of co-culturing human MSCs (hMSCs) with rabbit articular chondrocytes (rACs) to promote chondrogenic and osteogenic differentiation of hMSCs for clinical osteoarthritic therapy were investigated in the present study. The two distinct cell types were encapsulated in alginate hydrogels singly or in one of three ratios (2:1, 1:1, 1:2 of hMSCs to rACs) and cultured under chondrogenic conditions for 28 days. The results demonstrated that newly synthesized cartilaginous extracellular matrix (ECM) and type II collagen (col-2) gene signal were upregulated with greater hMSC ratios and longer culture periods. However, a specific col-2 gene probe for human was found only in single hMSC group but absent in all co-culture groups, which indicate that the enhanced cartilaginous phenotype originated from the co-cultured rACs. Osseous phenotype was histologically detected only in the 2:1 group on day 28; and xenogenic osteocalcin assay showed that it originated from hMSCs. This suggests that variations in the ratios of co-cultured hMSC and rAC regulated the cartilaginous and osseous phenotype as well as the differentiation of hMSCs in alginate constructs. The study provides new insights into the role of cell-cell interactions in regulating both cell differentiation and cell function and highlights the importance of developing appropriate differentiation protocols for tissue engineering therapies.
authors: Division of Stem Cell and Tissue Engineering, State Key Laboratory of Biotherapy, West China Hospital, West China Medicine School, Sichuan University, Chengdu, China.
authors: Xiang-tao
authors: XT
authors: Mo
authors: Shang-chun
authors: SC
authors: Guo
authors: Hui-qi
authors: HQ
authors: Xie
authors: Li
authors: L
authors: Deng
authors: Wei
authors: W
authors: Zhi
authors: Zhou
authors: Z
authors: Xiang
authors: Xiu-qun
authors: XQ
authors: Li
authors: Zhi-ming
authors: ZM
authors: Yang
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D001842:Bone and Bones / Q000166:cytology* / Q000187:drug effects*; D002356:Cartilage / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D002469:Cell Separation; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects; D018920:Coculture Techniques; D004247:DNA / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D020723:Glucuronic Acid / Q000494:pharmacology; D006603:Hexuronic Acids / Q000494:pharmacology; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D015675:Osteocalcin / Q000378:metabolism; D010641:Phenotype; D011817:Rabbits
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D015675:Osteocalcin; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid; D004247:DNA