Inflammatory Factors Combined With Stimulation Of Adipose-derived Mesenchymal Stem Cells Promote Acute Wound Healing In Mice

Skin wound healing is a complex process,which requires the mutual regulation of various cells and bioactive substances,and mainly goes through hemostasis,inflammation,proliferation and remodeling.Disorders at any stage can cause chronic wounds and scars that are difficult to heal,not only causing severe pain to patients,but also a heavy economic burden to the society and patients.It is a problem that the whole society cannot ignore.Recent studies have shown that stem cells play a key role in wound repair due to their differentiation potential and paracrine effects.Adipose-derived mesenchymal stem cells(ADSCs)are beneficial to the wound healing process by accelerating skin wound healing,collagen deposition,neovascularization and cell infiltration,thus promoting wound repair.Stimulation of ADSCs by inflammatory factors(IFN-γ,TNF-α)can improve their biological functions and promote paracrine effects.Dermal fibroblasts(HDFs)play an important role in wound healing and can influence extracellular matrix formation and collagen deposition.Therefore,this study investigated the effects of conditioned medium of ADSCs stimulated by inflammatory factors on wound healing and HDF.In this study,(1)adipose-derived mesenchymal stem cells(ADSCs)were extracted from human adipose tissue,and ADSCs were successfully extracted by microscopic observation,flow cytometric identification and identification of adipogenic and osteogenic differentiation.(2)Inflammatory factors(IFN-γ,TNF-α)stimulated ADSCs to explore the effect on the biological function of ADSCs.ELISA was used to detect the secretion of b FGF,VEGF,PDGF-BB,IL-6,IL-4 and IL-13 cytokines was significantly increased.(3)Full-thickness skin defect modeling was performed on the back of mice,and equal volumes of DMEM,ADSCsCM and IT-ADSCs-CM were injected around the wound for treatment.Morphological photographs were taken on the 3rd,7th and 14 th days,The wound healing rate of the CM group was significantly improved;Tissues were taken on the 3rd,7th and 14 th days,and the tissue sections were subjected to HE staining and Masson staining for observation and statistics.IT-ADSCs-CM could accelerate wound healing;Observation and statistics of immunofluorescence staining,after IT-ADSCs-CM treatment,M1-type pro-inflammatory macrophages decreased and M2-type anti-inflammatory macrophages increased in mice wound tissue,which promoted epithelial regeneration in mice wounds,promoted the formation of new blood vessels in mice wounds,and improved collagen deposition in mice wounds,Therefore,IT-ADSCs-CM can promote wound healing in mice.(4)Dermal fibroblasts were extracted from human foreskin tissue,and the experiments were divided into DMEM group,ADSCs-CM group and IT-ADSCs-CM group.CCK-8 and scratch experiments showed that IT-ADSCs-CM treatment promoted HDF proliferation and migration;Cell immunofluorescence,western blot and q RT-PCR experiments found that fibroblasts in the ITADSCs-CM group differentiated into myofibroblasts and promoted the deposition of type I collagen and type III collagen.Western blot experiments confirmed that it may be related to the regulation of IT-ADSCs-CM through PI3K/AKT signaling pathway.Therefore,this study can conclude that ADSCs stimulated by inflammatory factors(IFN-γ,TNF-α)can promote wound healing and regulate the biological behavior of cells through paracrine action.