In vitro stage‐specific chondrogenesis of mesenchymal stem cells committed to chondrocytes

Abstract

Objective. Osteoarthritis is characterized by an imbalance in cartilage homeostasis, which could potentially be corrected by mesenchymal stem cell (MSC)-based therapies. However, in vivo implantation of undifferentiated MSCs has led to unexpected results. This study was undertaken to establish a model for preconditioning of MSCs toward chondrogenesis as a more effective clinical tool for cartilage regeneration.Methods. A coculture preconditioning system was used to improve the chondrogenic potential of human MSCs and to study the detailed stages of chondrogenesis of MSCs, using a human MSC line, Kp-hMSC, in commitment cocultures with a human chondrocyte line, hPi (labeled with green fluorescent protein [GFP]). In addition, committed MSCs were seeded into a collagen scaffold and analyzed for their neocartilage-forming ability.Results. Coculture of hPi-GFP chondrocytes with Kp-hMSCs induced chondrogenesis, as indicated by the increased expression of chondrogenic genes and accumulation of chondrogenic matrix, but with no effect on osteogenic markers. The chondrogenic process of committed MSCs was initiated with highly activated chondrogenic adhesion molecules and stimulated cartilage developmental growth factors, including members of the transforming growth factor ␤ superfamily and their downstream regulators, the Smads, as well as endothelial growth factor, fibroblast growth factor, insulin-like growth factor, and vascular endothelial growth factor. Furthermore, committed Kp-hMSCs acquired neocartilageforming potential within the collagen scaffold. Osteoarthritis (OA), one of the most common musculoskeletal diseases, has been ascribed to an imbalance in cartilage homeostasis in the aging process (1,2). Hyaline cartilage has little capacity for self-repair. As a result, continuous mechanical stress can lead to the degradation of articular cartilage, culminating in a vicious cycle of destructive processes (3). Many therapeutic interventions directed at the restoration of the reparative capacity of chondrocytes have been explored (3-5). One of the emerging approaches is cell-based therapy, in which expanded chondrocytes are used for cartilage repair. However, the outcome of this approach has been disappointing, due to the difficulties in maintaining chondrocytic phenotypes and the decrease in proliferative capacity of autologous chondrocytes with increasing age (1,6,7). Conclusion. These findings help define the molecular markers of chondrogenesis and more accuratelyCell therapy based on autologous mesenchymal stem cells (MSCs), which have a vast proliferative ca-

Engineering Musculoskeletal Tissues with Human Embryonic Germ Cell Derivatives

“…In recent years, a number of studies have demonstrated chondrocyte-mediated chondrogenic differentiation of stem cells [36,[41][42][43]. A variety of unidentified morphogenetic factors from chondrocytes such as growth factors, hormones, and ECM influence the chondrogenesis of LVEC cells either individually or in synergy with other factors such as TGF-b1.…”

Cell-Derived Polymer/Extracellular Matrix Composite Scaffolds for Cartilage Regeneration, Part 1: Investigation of Cocultures and Seeding Densities for Improved Extracellular Matrix Deposition

“…Coculturing chondrocytes together with MSCs takes advantage of both secreted factors and direct cell-to-cell contact to direct differentiation and potentially stimulate matrix production. [28][29][30] The objective of this study was to determine the optimal ratio of chondrocytes to MSCs that results in dense and well-distributed cartilage-like ECM deposition within a fibrous polymeric scaffold, while minimizing the required number of chondrocytes. This was performed by culturing in fetal bovine serum (FBS) containing media without exogenous growth factor supplementation.…”

Indirect co-culture with tenocytes promotes proliferation and mRNA expression of tendon/ligament related genes in rat bone marrow mesenchymal stem cells

“…Moreover, this in vitro culture system made MSCs fate more controllable than in vivo and easier for understanding the molecular events within the crosstalk of MSCs and the local environment. Co-culturing with appropriate cell types, MSCs have been elucidated to commit to corresponding lineages, such as osteoblasts (Csaki et al 2009), chondrocytes (Chen et al 2009), ligament cells (Lee et al 2007), cardiomyocytes , hepatocytes (Lange et al 1999) and smooth muscle cells Ball et al 2004). Interestingly, direct cell-to-cell contact has been proven to be indispensable for the commitment of a sort of cell types, such as smooth muscle cells and cardiomyocytes Ball et al 2004).…”