PDGF-BB and IL-4 co-overexpression is a potential strategy to enhance mesenchymal stem cell-based bone regeneration

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.

The effect of genetically modified platelet-derived growth factor-BB over-expressing mesenchymal stromal cells during core decompression for steroid-associated osteonecrosis of the femoral head in rabbits

“…A wide array of promoters has been used for gene expression in various cell types transduced with lentiviral vectors [ 27 – 29 ]. Specifically, the CMV and PGK promoters have been previously utilized to stimulate gene expression in genetically modified MSCs [ 16 , 30 , 31 ]. Interestingly, prior studies have noted that the CMV promoter activity may be greater or lower than the PGK depending on the type of cell that is transduced [ 31 – 33 ].…”

“…Two distinct types of PDGF-BB-MSCs were generated by infecting MSCs with the lentiviral vector carrying the human PDGF-BB gene under the cytomegalovirus (CMV) and human phosphoglycerate kinase (PGK) promoter, respectively. Briefly, the pCDH-CMV-PDGF-BB-EF1a-copGFP plasmid was constructed by insertion of PDGF-BB coded genes into the control transfer plasmid, pCDH-CMV-MCS-EF1a-copGFP (System Biosciences, Palo Alto, CA), and the pCDH-PGK-PDGF-BB-EF1a-copGFP plasmid was constructed by replacing the CMV promoter in pCDH-CMV-PDGF-BB-EF1a-copGFP with the PGK promoter from pCDH-PGK (Addgene, Watertown, MA) [ 16 ]. The control lentivirus vectors or PDGF-BB-overexpressing lentivirus vectors were produced in human embryonic 293 T cells (ATCC, Manassas, VA) by co-transfecting with the control or PDGF-BB-overexpressing transfer plasmids, packaged plasmid (psPAX2), and enveloped plasmid (pMD2G VSVG) using a calcium phosphate transfection kit (Takara Bio USA, Inc., Mountain View, CA) with 25 mmol/L chloroquine.…”

“…Our group recently demonstrated that murine MSCs that were genetically modified to overexpress PDGF-BB accelerated cellular proliferation and promoted greater osteogenesis and mineralization in vitro [ 16 ]. Given these findings, we hypothesized that the addition of MSCs genetically modified to overexpress PDGF-BB may improve the outcomes of CD in the treatment of ONFH.…”

Mesenchymal Stem Cells and NF-κB Sensing Interleukin-4 Over-Expressing Mesenchymal Stem Cells Are Equally Effective in Mitigating Particle-Associated Chronic Inflammatory Bone Loss in Mice

“…Mesenchymal stem cells (MSCs) have shown great potential in skeletal tissue regeneration ( Caplan, 1991 ; Zhang et al, 2021 ). Previously we showed an intervention using unaltered MSCs during the chronic inflammatory phase could mitigate the adverse effects of contaminated particles on bone ( Utsunomiya et al, 2021a ).…”

“…Previously we showed an intervention using unaltered MSCs during the chronic inflammatory phase could mitigate the adverse effects of contaminated particles on bone ( Utsunomiya et al, 2021a ). Furthermore, specific properties of MSCs, such as differentiation capability and immunomodulation potential can be further refined by genetic modification to optimize MSC-based therapy ( Wei et al, 2018 ; Zhang et al, 2021 ). Whether local delivery of genetically modified MSCs could abrogate the adverse effects of particles on bone in vivo , using the murine continuous femoral infusion model is unknown.…”