Baculovirus-Mediated Growth Factor Expression in Dedifferentiated Chondrocytes Accelerates Redifferentiation: Effects of Combinational Transduction

Abstract

Transduction of partially dedifferentiated rabbit chondrocytes with a baculovirus (Bac-CB) expressing bone morphogenetic protein-2 (BMP-2) reverses dedifferentiation and enhances matrix production. Hereby we examined whether transduction with Bac-CB in combination with another baculovirus expressing transforming growth factor-beta1 (TGF-beta1) or insulin-like growth factor-1 (IGF-1) synergistically augmented chondrogenic differentiation. Passage 3 rabbit articular chondrocytes were transduced by different baculovirus combinations: single transduction with Bac-CB, cotransduction with Bac-CB and Bac-CT (expressing TGF-beta1), cotransduction with Bac-CB and Bac-CI (expressing IGF-1), and transduction with Bac-CB followed by repeated transduction with Bac-CT, Bac-CI, or Bac-CB 5 days later. Transduced cells were encapsulated into alginate beads for culture. Among these strategies, only cotransduction with Bac-CB and Bac-CT led to improved redifferentiation when compared with Bac-CB single transduction, as evidenced by the enhanced expression of aggrecan and collagen IIB (Col IIB), suppressed expression of Col I and Col X, emergence of chondrocyte-specific lacunae, and elevated deposition of matrix molecules. The cotransduction also accelerated the expression of Sox9, Col IIB, and aggrecan. In summary, baculovirus-mediated coexpression of TGF-beta1 and BMP-2 synergistically accelerates the chondrocyte redifferentiation process and improves the maintenance of chondrocyte phenotype and accumulation of cartilage-specific matrix molecules.

Spinner-flask culture induces redifferentiation of de-differentiated chondrocytes

“…Culture in various types of three-dimensional scaffolds or hydrogels have been shown to re-differentiate de-differentiated chondrocytes (Capito and Spector 2006;Lin et al 2008;Malda et al 2003;Melero-Martin et al 2006;Stevens et al 2004;Takahashi et al 2007;Veilleux et al 2004). Growth factors, such as insulin-like growth factor-1, bone morphogenic protein-2 and TGF, also induce re-differentiation of de-differentiated chondrocytes (Liu et al 2007;Sung et al 2009). However, these methods require additional materials, which would increase the cost but hardly produce sufficient numbers of re-differentiated chondrocytes.…”

“…The statistical analysis was performed between the same culture period secreted a higher level of TGF-b and exhibited a morphology of differentiated chondrocytes (Kessler and Grande 2008). TGF-b induces redifferentiated chondrocyte (Sung et al 2009;Liu et al 2007). In spinner culture of chondrocytes, the redifferentiation could be caused in part by enhanced TGF-b secretion, which was stimulated by shear stress.…”

How to avoid complement attack in baculovirus-mediated gene delivery

“…These studies have been followed by extensive work by Hu and co-workers, who have demonstrated the potential of baculovirus as a delivery vector for cartilage and bone tissue engineering (Lin et al, 2010b). The first indication of the possibility to use baculovirus vectors for cartilage engineering came from studies demonstrating efficient gene transfer into articular chondrocytes (Ho et al, 2004;Sung et al, 2007), which by combination of growth factor expression, such as bone morphogenetic protein-2 (BMP-2) and rotating-shaft bioreactor culture, allowed formation of hyaline cartilaginous tissues (Chen et al, , 2008Sung et al, 2009). When the chondrocyte cultures engineered this way were implanted into rabbits they were able to repair osteochondral defects at the patellar grooves .…”

Redifferentiation of Dedifferentiated Chondrocytes by Adenoviral Vector-Mediated TGF-β3 and Collagen-1 Silencing shRNA in 3D Culture

“…Lin et al 15 found that adenoviral vector-mediated BMP-4 had capability to recover chondrocytic phenotype of dedifferentiated chondrocytes in vitro and in vivo. A series of studies by Sung et al 23,24 demonstrated that transfer of BMP-2 or TGF-b1 via baculovirus could induce redifferentiation of dedifferentiated chondrocytes. Especially, the co-transduction of baculovirus-BMP-2 and baculovirus-TGF-b1 elevated the production of cartilaginous ECM molecules and maintained the chondrocytic phenotype.…”