title: Redifferentiation of dedifferentiated chondrocytes by adenoviral vector-mediated TGF-β3 and collagen-1 silencing shRNA in 3D culture.
abstract: Autologous chondrocytes remain one of the most preferable candidates among various therapeutic cell species because of their high efficacy, despite remarkable progress in discovery and development of therapeutic cells for cartilage regenerative medicine to date. However, the essential process of cell expansion via repeated monolayer sub-cultures inevitably induces chondrocytic dedifferentiation. In this study, we aimed to achieve and enhance redifferentiation of dedifferentiated chondrocytes with dual genes of transforming growth factor (TGF)-β3 and short hairpin RNA (shRNA) that restore chondrocytic phenotype and silence fibrous collagen type I (Col I), respectively. It was hypothesized that gene delivery of the two targets would promote chondrogenesis in chondrocytes, and meanwhile inhibit the expression of the undesired Col I. Three types of recombinant adenoviruses were constructed. Two of them were of single-function vectors with the ability to express either TGF-β3 (Ad-TGFβ3) or shRNA (specific for Col I, Ad-shRNA); the third type was of double-function vectors that encode both TGF-β3 and anti-Col I shRNA (Ad-double). We infected the dedifferentiated chondrocytes with Ad-double, or co-transduced them with Ad-TGFβ3 and Ad-shRNA at the same time (designated as Ad-combination). Data from real-time RT-PCR and histological staining suggested a restoration in the expression of cartilage-specific genes including aggrecan, type II collagen, and cartilage oligomeric matrix protein (COMP); while a significant down-regulation of Col I expression was observed in groups treated with Ad-double and Ad-combination compared to other control groups. These results demonstrated that, by genetic modification, dedifferentiated chondrocytes managed to redifferentiate back to chondrocytic phenotype, which may greatly facilitate cartilage regenerative medicine by providing sufficient number of competent therapeutic cells.
authors.affiliation: Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Republic of Singapore.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Yongchang
authors.initials: Y
authors.lastname: Yao
authors.forename: Kai
authors.initials: K
authors.lastname: Su
authors.forename: Patricia Xiaotian
authors.initials: PX
authors.lastname: Pang
authors.forename: Ruijie
authors.initials: R
authors.lastname: Zhou
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Dong-An
authors.initials: DA
authors.lastname: Wang
mesh_terms: D000256:Adenoviridae; D053674:Aggrecans / Q000096:biosynthesis; D000818:Animals; D054337:Cell Dedifferentiation; D002454:Cell Differentiation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology*; D024042:Collagen Type I / Q000235:genetics*; D024043:Collagen Type II / Q000096:biosynthesis; D020868:Gene Silencing; D005822:Genetic Vectors; D006801:Humans; D013552:Swine; D053782:Transforming Growth Factor beta3 / Q000235:genetics*
chemical_list: D053674:Aggrecans; D024042:Collagen Type I; D024043:Collagen Type II; D053782:Transforming Growth Factor beta3