TGF-ß1 overexpressing human MSCs generated using gene editing show robust therapeutic potential for treating collagen-induced arthritis.

Transforming growth factor ß (TGF-ß) plays a pivotal role in cartilage differentiation and other functions of mesenchymal stem cells (MSCs). In this study, we investigated the therapeutic potential of TGF-ß1 overexpressing amniotic MSCs (AMMs) generated using gene editing in a mouse model of damaged cartilage. The TGF-ß1 gene was inserted into a safe harbor genomic locus in AMMs using transcription activator-like effector nucleases. The chondrogenic properties of TGF-ß1-overexpressing AMMs (AMM/T) were characterized using reverse transcription polymerase chain reaction (RT-PCR), quantitative RT-PCR, and histological analysis, and their therapeutic effects were evaluated in mouse model of collagen-induced arthritis (CIA). AMM/T expressed cartilage-specific genes and showed intense Safranin O and Alcian blue staining. Furthermore, injecting AMM/T attenuated CIA progression compared with AMM injection, and increased the regulatory T (Treg) cell population, while suppressing T helper (Th)17 cell activation in CIA mice. Proinflammatory factors, such as interleukin-1ß (IL-1ß), IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α were significantly decreased in AMM/T injected CIA mice compared with their AMM injected counterparts. In conclusion, genome-edited AMMs overexpressing TGF-ß1 may be a novel and alternative therapeutic option for protecting cartilage and treating inflammatory joint arthritis.

Minicircle-based GCP-2 ex vivo gene therapy enhanced the reepithelialization and angiogenic capacity.

Recently, minicircle (MC)-based cell therapy has been emerging as a novel technology for nonviral genetic modification. In this study, we investigated the characteristics of granulocyte chemotactic protein-2 (GCP-2)-overexpressing fibroblasts (GCP-2/MC) using MC microporation technology, as well as its therapeutic mechanism in wound healing. GCP-2 parent plasmid and MC containing GCP-2 were generated. Human dermal fibroblasts (HDF) were transfected with MC containing GCP-2. Quantitative reverse transcription polymerase chain reaction (qRT-PCR), scratch wound assay, and in vivo wound healing assay were performed. Gene and protein expression analysis revealed that GCP-2/MC highly expressed epithelialization growth factor, epidermal growth factor (EGF), chemokines, GCP-2, interleukin (IL)-8, as well as wound healing-associated genes such as insulin growth factor (IGF)-1 and hepatocyte growth factor (HGF). An in vitro scratch wound closure and matrigel tube formation assays demonstrated that the culture medium derived from GCP-2/MC substantially accelerated the wound closure and matrigel network formation. Wounds in nude mice were created by skin excisions followed by injections of GCP-2/MC. Results showed high cell survival potential and that GCP-2/MC transplantation highly accelerated skin wound closure by increasing reepithelialization, capillary density, and enhancing angiogenic factors, suggesting direct benefits for cutaneous closure. Taken together, these data suggest that MC-based GCP-2 overexpression could be a promising alternative strategy for promoting wound healing.

IL-10-secreting human MSCs generated by TALEN gene editing ameliorate liver fibrosis through enhanced anti-fibrotic activity.

Mesenchymal stem cells (MSCs) are known for their ability to repair liver damage. However, their therapeutic potential still needs to be enhanced. In the present study, we produced genome-edited MSCs that secrete interleukin 10 (IL-10) and evaluated their therapeutic potential in a liver fibrosis model. Multiple copies of the IL-10 gene were inserted into a safe harbor genomic locus in amniotic mesenchymal stem cells (AMMs) using transcription activator-like effector nucleases (TALENs). The IL-10 gene-edited AMMs (AMM/I) were characterized by reverse transcription PCR (RT-PCR), quantitative RT-PCR (qRT-PCR), and microarray. The effects of AMM/I-conditioned cell medium (CM) on the activation of hepatic stellate cells (HSC) were analyzed in vitro and in vivo therapeutic assays were performed on a mouse liver fibrosis model. The engineered AMM/I expressed high levels of IL-10. AMM/I-CM inhibited the activation of HSC (in vitro) and TNF-α expression of T cells/macrophage derived from fibrotic liver. In addition, human IL-10 was detected in the serum of the mice transplanted with AMM/I and transplantation of AMM/I significantly inhibited thioacetamide (TAA)-induced liver fibrosis and ameliorated abnormal liver function. Furthermore, a high number of human albumin-expressing AMM/I were successfully engrafted into the liver of recipient mice. Overall, genome-edited AMMs overexpressing anti-fibrotic IL-10 might be a promising alternative therapeutic option for the treatment of liver cirrhosis.

Dual chemotactic factors-secreting human amniotic mesenchymal stem cells via TALEN-mediated gene editing enhanced angiogenesis.

BACKGROUND: Even though mesenchymal stem cells (MSCs) have angiogenic property, their cytokine secretory capacity is limited to treat ischemic vascular disorders. In present study, we produced genome-edited MSCs that secreted dual chemokine granulocyte chemotactic protein-2 (GCP-2) and stromal-derived factor-1α (SDF-1α) and determined their therapeutic potential in the context of experimental ischemia. METHODS: GCP-2 and SDF-1α genes were integrated into safe harbor site at the safe harbor genomic locus of amniotic mesenchymal stem cells (AMM) via transcription activator-like effector nucleases (TALEN). GCP-2 and SDF-1α gene-edited AMM (AMM/GS) were used for quantitative (q)-PCR, Matrigel tube formation, cell migration, Matrigel plug assays and in vivo therapeutic assays using hindlimb ischemia mouse model. RESULTS: AMM/GS-derived culture media (CM) induced significantly higher tube lengths and branching points as compared to AMM/S CM and AMM CM. Interestingly, Matrigel plug assays revealed that significantly higher levels of red blood cells were found in AMM/GS than AMM/S and AMM Matigel plugs and exhibited micro-vascular like formation. Cells was transplanted into ischemic mouse hindlimbs and compared with control groups. AMM/GS injection prevented limb loss and augmented blood perfusion, suggesting that enhances neovascularization in hindlimb ischemia. In addition, transplanted AMM/GS revealed high vasculogenic potential in vivo compared with transplanted AMM/S. CONCLUSION: Taken together, genome-edited MSCs that express dual chemokine GCP-2 and SDF-1α might be alternative therapeutic options for the treatment of ischemic vascular disease.