Peripheral blood aspirates overexpressing IGF‐I via rAAV gene transfer undergo enhanced chondrogenic differentiation processes

Abstract

Implantation of peripheral blood aspirates induced towards chondrogenic differentiation upon genetic modification in sites of articular cartilage injury may represent a powerful strategy to enhance cartilage repair. Such a single‐step approach may be less invasive than procedures based on the use of isolated or concentrated MSCs, simplifying translational protocols in patients. In this study, we provide evidence showing the feasibility of overexpressing the mitogenic and pro‐anabolic insulin‐like growth factor I (IGF‐I) in human peripheral blood aspirates via rAAV‐mediated gene transfer, leading to enhanced proliferative and chondrogenic differentiation (proteoglycans, type‐II collagen, SOX9) activities in the samples relative to control (reporter rAAV‐lacZ) treatment over extended periods of time (at least 21 days, the longest time‐point evaluated). Interestingly, IGF‐I gene transfer also triggered hypertrophic, osteo‐ and adipogenic differentiation processes in the aspirates, suggesting that careful regulation of IGF‐I expression may be necessary to contain these events in vivo. Still, the current results demonstrate the potential of targeting human peripheral blood aspirates via therapeutic rAAV transduction as a novel, convenient tool to treat articular cartilage injuries.

Reduced bone length, growth plate thickness, bone content, and IGF-I as a model for poor growth in the CFTR-deficient rat

“…IGF-I treatment has been utilized to improve linear growth in non-CF children [ 30 ], and improves bone density in disease states with reduced anabolic drive (such as anorexia) [ 31 ]. More recent studies are examining therapeutic ways to improve cartilage growth and repair with IGF-I [ 32 , 33 ]. Although IGF-I and/or GH supplementation have not been studied in CF animal models (specifically evaluating bone metabolism and cartilage growth), our data suggest the importance of such studies to improve understanding of growth mechanism.…”

Regenerative Medicine: A Review of the Evolution of Autologous Chondrocyte Implantation (ACI) Therapy

“…IGF-1 delivery from a scaffold has been shown to promote GAG content and chondrogenic phenotype for human chondrocytes in vitro [104]. This has also been replicated with BM-MSCs, which increase in cell number upon transfection with IGF-1 [105]. Equine models have confirmed the maintenance of increased collagen II and GAG levels upon transplantation [106].…”

Controlled Release of rAAV Vectors from APMA-Functionalized Contact Lenses for Corneal Gene Therapy

“…rAAV-lacZ carries the lacZ gene encoding Escherichia coli β-galactosidase (β-gal), rAAV-RFP the Discosoma sp. red fluorescent protein (RFP) gene, and rAAV-hIGF-I a human insulin-like growth factor I (hIGF-I) cDNA (536 bp), all under the control of the cytomegalovirus immediate-early promoter [39,[42][43][44]. The vectors were packaged as conventional (not self-complementary) vectors using a helper-free, two-plasmid transfection system in 293 cells with the packaging plasmid pXX2 and the adenovirus helper plasmid pXX6 as previously described [39,[42][43][44].…”

“…red fluorescent protein (RFP) gene, and rAAV-hIGF-I a human insulin-like growth factor I (hIGF-I) cDNA (536 bp), all under the control of the cytomegalovirus immediate-early promoter [39,[42][43][44]. The vectors were packaged as conventional (not self-complementary) vectors using a helper-free, two-plasmid transfection system in 293 cells with the packaging plasmid pXX2 and the adenovirus helper plasmid pXX6 as previously described [39,[42][43][44]. The vector preparations were purified by dialysis and titrated by real-time PCR [39,[42][43][44], averaging 10 10 transgene copies/mL (≈1/500 functional recombinant viral particles).…”