Generation of Scaffoldless Hyaline Cartilaginous Tissue from Human iPSCs

Abstract

SummaryDefects in articular cartilage ultimately result in loss of joint function. Repairing cartilage defects requires cell sources. We developed an approach to generate scaffoldless hyaline cartilage from human induced pluripotent stem cells (hiPSCs). We initially generated an hiPSC line that specifically expressed GFP in cartilage when teratoma was formed. We optimized the culture conditions and found BMP2, transforming growth factor β1 (TGF-β1), and GDF5 critical for GFP expression and thus chondrogenic differentiation of the hiPSCs. The subsequent use of scaffoldless suspension culture contributed to purification, producing homogenous cartilaginous particles. Subcutaneous transplantation of the hiPSC-derived particles generated hyaline cartilage that expressed type II collagen, but not type I collagen, in immunodeficiency mice. Transplantation of the particles into joint surface defects in immunodeficiency rats and immunosuppressed mini-pigs indicated that neocartilage survived and had potential for integration into native cartilage. The immunodeficiency mice and rats suffered from neither tumors nor ectopic tissue formation. The hiPSC-derived cartilaginous particles constitute a viable cell source for regenerating cartilage defects.

Activin-A enhances mTOR signaling to promote aberrant chondrogenesis in fibrodysplasia ossificans progressiva

“…The resultant luminescent signal was measured on PowerScan 4 (DS Pharma Biomedical). The inhibitory effects of the von Kossa, safranin O, human-specific anti-vimentin antibody, or collagen I antibody as previously described (38,80,85). Quantitative PCR analysis.…”

<b>Hyaline cartilage formation and tumorigenesis of implanted tissues derived from human induced pluripotent stem </b><b>cells </b>

“…Transplantation of iPSC-derived tissues involves supplemented with 1% FBS, ITS, WNT3A, Activin A, bFGF, BMP2, TGFb, and GDF5 (14). They performed three-dimensional culture for 28-70 days to mature the differentiated hiPSCs, and observed no tumor formation in the following transplantation analyses (14).…”

“…They performed three-dimensional culture for 28-70 days to mature the differentiated hiPSCs, and observed no tumor formation in the following transplantation analyses (14). Considering the high nutritional requirement of immature hiPSCs, long-term culture with low FBS may be essential to omit immature hiPSCs, as well as to prepare a matured cartilage tissue in vitro.…”

“…In addition, iPSCs are free from ethical concerns that are inevitable when using embryonic stem cells (ESCs). Several studies have shown the potential of iPSCs in cartilage regenerative medicine (9,(12)(13)(14). On the other hand, the risk of tumorigenesis should be considered in the clinical application of human iPSCs (hiPSCs) (13).…”

Ten years of induced pluripotency: from basic mechanisms to therapeutic applications

“…He also showed how to expand nephron progenitors from mouse embryos and human iPSCs in vitro, generating a number that should be sufficient for future regenerative medicine (Tanigawa et al, 2016). Finally, Nori Tsumaki (CiRA, Japan) explained how iPSCs could be used to produce chondrocytes that generate hyaline cartilage rather than fibrous cartilage, which is unlike current cell therapies for cartilage (Yamashita et al, 2015). This accomplishment is due, in part, to the expansion of iPSCs and not of chondrocytes in the protocol.…”