Gene Therapy for Bone Repair Using Human Cells: Superior Osteogenic Potential ofBone Morphogenetic Protein 2–Transduced Mesenchymal Stem Cells Derived from Adipose Tissue Compared to Bone Marrow

Abstract

Ex vivo regional gene therapy strategies using animal mesenchymal stem cells genetically modified to overexpress osteoinductive growth factors have been successfully used in a variety of animal models to induce both heterotopic and orthotopic bone formation. However, in order to adapt regional gene therapy for clinical applications, it is essential to assess the osteogenic capacity of transduced human cells and choose the cell type that demonstrates the best clinical potential. Bone-marrow stem cells (BMSC) and adipose-derived stem cells (ASC) were selected in this study for in vitro evaluation, before and after transduction with a lentiviral two-step transcriptional amplification system (TSTA) overexpressing bone morphogenetic protein 2 (BMP-2; LV-TSTA-BMP-2) or green fluorescent protein (GFP; LV-TSTA-GFP). Cell growth, transduction efficiency, BMP-2 production, and osteogenic capacity were assessed. The study demonstrated that BMSC were characterized by a slower cell growth compared to ASC. Fluorescence-activated cell sorting analysis of GFP-transduced cells confirmed successful transduction with the vector and revealed an overall higher but not statistically significant transduction efficiency in ASC versus BMSC (90.2 ± 4.06% vs. 80.4 ± 8.51%, respectively; p = 0.146). Enzyme-linked immunosorbent assay confirmed abundant BMP-2 production by both cell types transduced with LV-TSTA-BMP-2, with BMP-2 production being significantly higher in ASC versus BMSC (239.5 ± 116.55 ng vs. 70.86 ± 24.7 ng; p = 0.001). Quantitative analysis of extracellular deposition of calcium (Alizarin red) and alkaline phosphatase activity showed that BMP-2-transduced cells had a higher osteogenic differentiation capacity compared to non-transduced cells. When comparing the two cell types, ASC/LV-TSTA-BMP-2 demonstrated a significantly higher mineralization potential compared to BMSC/LV-TSTA-BMP-2 7 days post transduction (p = 0.014). In conclusion, this study demonstrates that transduction with LV-TSTA-BMP-2 can significantly enhance the osteogenic potential of both human BMSC and ASC. BMP-2-treated ASC exhibited higher BMP-2 production and greater osteogenic differentiation capacity compared to BMP-2-treated BMSC. These results, along with the fact that liposuction is an easy procedure with lower donor-site morbidity compared to BM aspiration, indicate that adipose tissue might be a preferable source of MSCs to develop a regional gene therapy approach to treat difficult bone-repair scenarios.

Mesenchymal Stem Cells for Regenerative Medicine

“…However, these hDPSCs are screened from a stromal vascular dental pulp fraction; therefore, this represents a limited source for further research and application. Since ADSCs can be routinely isolated from lipoaspirate with a high degree of purity with minimal donor site morbidity or patient discomfort, ADSCs are considered to have the most significant potential as a primary source for clinical bone tissue engineering [48,56,57]. Additional comparative and screening studies are necessary to identify other cell sources with applications in bone reconstruction.…”

Topography: A Biophysical Approach to Direct the Fate of Mesenchymal Stem Cells in Tissue Engineering Applications

“…Owing to their ability to differentiate into chondrocytes, MSCs have also been evaluated in the context of cartilage repair [ 33 ]. BM-MSCs, AD-MSCs but also synovium-derived MSCs (S-MSCs) [ 53 ] have been broadly studied in this context [ 53 , 54 ]. While BM-MSCs have shown the best results in terms of chondrogenic differentiation both in vitro and in vivo; S-MSCs have demonstrated enhanced proliferation [ 33 , 53 ].…”

Focal adhesion kinase promotes BMP2‐induced osteogenic differentiation of human urinary stem cells via AMPK and Wnt signaling pathways

“…These data suggested that hUSCs have the potential to differentiate into osteoblasts. BMP2 is a major member of the BMP family which exhibits strong osteoinductive ability and can induce osteogenic differentiation of adult stem cells such as bone marrow mesenchymal stem cells (BMSCs), adipose mesenchymal stem cells, embryonic stem cells, gingival mesenchymal stem cells, and periodontal ligament stem cells (Bougioukli et al, 2018;Ghaderi et al, 2018;Miao et al, 2018). However, the effects of BMP2 on osteogenic induction of hUSCs have not been reported and the underlying mechanism deserves further exploration to meet the requirements of seed cells for bone tissue engineering.…”