E2F1-Deficient Adipose-Derived Stem Cells Improve Wound Closure in Mice by Up-Regulating Expression of VEGF and TGF-β1

Background: Wound healing is a widespread health problem that imposes a financial burden on health systems. Cell therapy with genetically modified adipose-derived stem cells (ADSCs) is a promising strategy for dysregulated wound repair. E2F transcription factor 1 (E2F1) is a bidirectional regulator of cytokines. Here, the authors aimed to investigate the impact and potential mechanism of E2F1 -/- ADSCs in promoting the wound healing process.

Methods: Forty-five C57BL/6 mice (specific pathogen-free, male) with 10-mm full-thickness wounds were randomly treated with subcutaneous injection of 2 × 10 6 wild-type ADSCs, 2 × 10 6 E2F1 -/- ADSCs, or phosphate-buffered saline. The wound closure rate was monitored at days 0, 3, 7, 10, and 14 after treatment. The collagen synthesis, angiogenesis, and wound contraction were calculated by Masson, immunohistochemistry, and immunofluorescent staining (CD31 and KI67), Western blotting (α-smooth muscle actin, collagen I, vascular endothelial growth factor, and transforming growth factor-β1) separately at day 14. In vitro, the conditioned media (CM) of wild-type ADSCs and E2F1 -/- ADSCs were collected to evaluate the impact on proliferation, migration, and angiogenesis.

Results: In vivo, the E2F1 -/- ADSC group exhibited increased healing rate, proliferating vessels, and collagen synthesis compared with control at day 14 ( P < 0.05). Moreover, E2F1 -/- ADSCs showed enhanced vascular endothelial growth factor and transforming growth factor-β1 expression in the wound site and CM, and the CM from E2F1 -/- ADSCs promoted the proliferation, migration, and tube formation of co-cultured cells in vitro ( P < 0.05).

Conclusion: The E2F1 -/- ADSCs exhibited a strong paracrine ability to improve the vascularization process and collagen deposition, thereby accelerating wound healing in the rodent model.

Clinical relevance statement: These findings show that targeting transcription factor E2F1 could regulate the paracrine function of ADSCs, developing E2F1-modified ADSCs as an effective therapeutic option for wound healing and regeneration.