Ning Zhang1, Chi-Wen Lo1, Takeshi Utsunomiya1, Masahiro Maruyama1, Ejun Huang1, Claire Rhee1, Qi Gao1, Zhenyu Yao2, Stuart B Goodman3,4. 1. Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA. 2. Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA. zhenyuy@stanford.edu. 3. Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA. goodbone@stanford.edu. 4. Department of Bioengineering, Stanford University, Stanford, CA, USA. goodbone@stanford.edu.
Abstract
BACKGROUND: Mesenchymal stem cell (MSC)-based therapy has the potential for immunomodulation and enhancement of tissue regeneration. Genetically modified MSCs that over-express specific cytokines, growth factors, or chemokines have shown great promise in pre-clinical studies. In this regard, the anti-inflammatory cytokine interleukin (IL)-4 converts pro-inflammatory M1 macrophages into an anti-inflammatory M2 phenotype; M2 macrophages mitigate chronic inflammation and enhance osteogenesis by MSC lineage cells. However, exposure to IL-4 prematurely inhibits osteogenesis of MSCs in vitro; furthermore, IL-4 overexpressing MSCs inhibit osteogenesis in vivo during the acute inflammatory period. Platelet-derived growth factor (PDGF)-BB has been shown to enhance osteogenesis of MSCs with a dose-dependent effect. METHODS: In this study, we generated a lentiviral vector that produces PDGF-BB under a weak promoter (phosphoglycerate kinase, PGK) and lentiviral vector producing IL-4 under a strong promoter (cytomegalovirus, CMV). We infected MSCs with PDGF-BB and IL-4-producing lentiviral vectors separately or in combination to investigate cell proliferation and viability, protein expression, and the capability for osteogenesis. RESULTS: PDGF-BB and IL-4 co-overexpression was observed in the co-infected MSCs and shown to enhance cell proliferation and viability, and osteogenesis compared to IL-4 overexpressing MSCs alone. CONCLUSIONS: Overexpression of PDGF-BB together with IL-4 mitigates the inhibitory effect of IL-4 on osteogenesis by IL-4 overexpressing MSCS. PDGF-BB and IL-4 overexpressing MSCs may be a potential strategy to facilitate osteogenesis in scenarios of both acute and chronic inflammation.
BACKGROUND: Mesenchymal stem cell (MSC)-based therapy has the potential for immunomodulation and enhancement of tissue regeneration. Genetically modified MSCs that over-express specific cytokines, growth factors, or chemokines have shown great promise in pre-clinical studies. In this regard, the anti-inflammatory cytokine interleukin (IL)-4 converts pro-inflammatory M1 macrophages into an anti-inflammatory M2 phenotype; M2 macrophages mitigate chronic inflammation and enhance osteogenesis by MSC lineage cells. However, exposure to IL-4 prematurely inhibits osteogenesis of MSCs in vitro; furthermore, IL-4 overexpressing MSCs inhibit osteogenesis in vivo during the acute inflammatory period. Platelet-derived growth factor (PDGF)-BB has been shown to enhance osteogenesis of MSCs with a dose-dependent effect. METHODS: In this study, we generated a lentiviral vector that produces PDGF-BB under a weak promoter (phosphoglycerate kinase, PGK) and lentiviral vector producing IL-4 under a strong promoter (cytomegalovirus, CMV). We infected MSCs with PDGF-BB and IL-4-producing lentiviral vectors separately or in combination to investigate cell proliferation and viability, protein expression, and the capability for osteogenesis. RESULTS: PDGF-BB and IL-4 co-overexpression was observed in the co-infected MSCs and shown to enhance cell proliferation and viability, and osteogenesis compared to IL-4 overexpressing MSCs alone. CONCLUSIONS: Overexpression of PDGF-BB together with IL-4 mitigates the inhibitory effect of IL-4 on osteogenesis by IL-4 overexpressing MSCS. PDGF-BB and IL-4 overexpressing MSCs may be a potential strategy to facilitate osteogenesis in scenarios of both acute and chronic inflammation.
Authors: Tzu-Hua Lin; Taishi Sato; Katherine R Barcay; Heather Waters; Florence Loi; Ruth Zhang; Jukka Pajarinen; Kensuke Egashira; Zhenyu Yao; Stuart B Goodman Journal: Tissue Eng Part A Date: 2015-01-22 Impact factor: 3.845
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Authors: Jukka Pajarinen; Tzu-Hua Lin; Taishi Sato; Florence Loi; Zhenyu Yao; Yrjö T Konttinen; Stuart B Goodman Journal: PLoS One Date: 2015-11-10 Impact factor: 3.240