Regenerating cartilages by engineered ASCs: prolonged TGF-?3/BMP-6 expression improved articular cartilage formation and restored zonal structure.
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ABSTRACT: Adipose-derived stem cells (ASCs) hold promise for cartilage regeneration but their chondrogenesis potential is inferior. Here, we used a baculovirus (BV) system that exploited FLPo/Frt-mediated transgene recombination and episomal minicircle formation to genetically engineer rabbit ASCs (rASCs). The BV system conferred prolonged and robust TGF-?3/BMP-6 expression in rASCs cultured in porous scaffolds, which critically augmented rASCs chondrogenesis and suppressed osteogenesis/hypertrophy, leading to the formation of cartilaginous constructs with improved maturity and mechanical properties in 2-week culture. Twelve weeks after implantation into full-thickness articular cartilage defects in rabbits, these engineered constructs regenerated neocartilages that resembled native hyaline cartilages in cell morphology, matrix composition and mechanical properties. The neocartilages also displayed cartilage-specific zonal structures without signs of hypertrophy and degeneration, and eventually integrated with host cartilages. In contrast, rASCs that transiently expressed TGF-?3/BMP-6 underwent osteogenesis/hypertrophy and resulted in the formation of inferior cartilaginous constructs, which after implantation regenerated fibrocartilages. These data underscored the crucial role of TGF-?3/BMP-6 expression level and duration in rASCs in the cell differentiation, constructs properties and in vivo repair. The BV-engineered rASCs that persistently express TGF-?3/BMP-6 improved the chondrogenesis, in vitro cartilaginous constructs production and in vivo hyaline cartilage regeneration, thus representing a remarkable advance in cartilage engineering.
SUBMITTER: Lu CH
PROVIDER: S-EPMC3978803 | biostudies-other | 2014 Jan
REPOSITORIES: biostudies-other
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