Effects Of Endothelial-Mesenchymal Transiton During Cutaneous Wound Healing

Objective:To boserve the expressing feature of EnMT in human pathologic scar tissue and during mice cutaneous wound healing.Methods:Human tissue specimens were obtained from 10 pathologic scars and 10 normal skin.Specimens were made into paraffin sections.Expression of factorⅧrelated antigen andα-Smooth muscle actin(α-SMA) was detected by immunofluorescence assay.Forty-eight male Kunming mice were anaesthetized by intraperitioneal administration of pentobarbital sodium(30mg/kg body weight).Full-thickness skin wounds(1.5×1.5cm2) through the panniculus carnosus were made aseptically on the middle of back skin and near the neck.The wounds were left unsutured and without dressing.Skin samples,including a 5-mm margin of unwounded skin from each wound,were collected at days3,5,7,9,12 and 14 post-wounding.Normal mice skin for control group. Each group specimens were divided into two parts:one was made into frozen sections,and the other was used for isolate and culture endothelial cells,respectibvely,finally immunofluorescence assay was used for measure the factorⅧandα-SMA expression of frozen sections and isolated endothlial cells.At least four animals for each experimental time point were collected.Results:Immunofluorescence assay showed that factorⅧandα-SMA positive cells exists in the human pathologic scar tissue and during mice cutaneous wound healing.During cutaneous wound healing, a small number of factorⅧandα-SMA positive cells in control group. While it was significantly increased on postwounding Day 3,5,7,9 than in control group(P<0.01) and rose to a peak level on postwounding Day 7,then it gradually decreased to the normal level after postwounding Day 12 (P>0.05).Conclusions: EnMT exists in human pathologic scar tissue and during mice cutaneous wound healing,and the profile of EnMT exhibited a unimodal expression during cutaneous wound healing . Bojective: To boserve the different concentration TGF-β1 in promoting transformation of endothelial cells into interstitial cells and study the mechanism of EnMT during pathologic scarring and wound healing.Methods: Endothelial cells were isolated from human umbilical vein endothelial cells and cultured with different concentration of TGF-β1 (0,10,25 and 50ng/ml) for 72 h.Then,changes of cell morpholgy were observed under an inverted phase contrast microscope. Expression of FⅧrelated antigen andα-Smooth Muscle Actin(α-SMA) was detected by immunofluorescence assay.Expression of VE-cardherin,α-SMA and typeⅠcollagen was detected by RT-PCR.Results:A paving stone-like growth and a spindle-like growth of endothelial cells was observed in control group and TGF-β1 stimulating group,respectively.Immunofluorescence assay showed a small number of factorⅧandα-SMA positive cells in control group.The number of factorⅧandα-SMA positive cells was significantly greater in TGF-β1 group than in control group(P<0.05) and increased with the concentration of TGF-β1.The number of TGF-β1.RT-PCR showed that the expression level of VE-Cadherin significantly decreased with the concentration of TGF-β1(P< 0.05) while the expression level ofα-SMA and typeⅠcollagen significantly increased with concentration of TGF-β1(P<0.05).Conclusions: TGF-β1 promotes the transformation of endothelial cells into interstitial cells in a concentration-dependent manner.