Effects of matrix metalloproteinase 3 on wound healing: an experimental study / 解放军医学杂志

ABSTRACT

Objective To explore the changes and significance of matrix metalloproteinase 3 (MMP3) during wound healing in rat. Methods Wound fluids and dermal pluripotent stem cells (DPSCs) were isolated with routine method from rats, and they were purified and expanded. Wound fluid was collected on the first day to serve as wound microenvironment, then the responses of DPSCs to wound fluids were investigated, and the expression of MMP3 protein in DPSCs was determined by immunohistochemistry staining. Meanwhile, animal models were repruduced with cutaneous incision and suturing, and the animals were respectively assigned to intractable wound group, in which rats received whole body irradiation, and simple wound group, in which no irradiation was given. The rats were sacrificed on 3rd, 5th, 7th, 10th and 14th day posttrauma (n=5 each), and specimens of wound tissue were harvested, fixed with 10% formalin solution. Twenty four hours later, the samples were dehydrated and embeded, then paraffin section were made. Paraffin sections were stained with hematoxylin and eosin (HE) staining. Light microscopy was used to observe the pathological changes in wounds. Five randomly selected fields were observed under a ?40 objective to evaluate the histological features, especially the amount of tissue repairing cells in wounds. Furthermore, MMP3 contents in wound sites were determined by immunohistochemistry assay and image analysis. Results The expression of MMP3 in DPSCs increased significantly after stimulation by wound fluids. MMP3 contents in rats of simple wound group increased significantly, especially in the dermal tissues, and the peak value appeared 5-7 days after trauma. MMP3 contents in rats of intractable wound group were significantly less than those of simple wound group, and the time when the peak value appeared was also delayed till the 10th day after trauma. Conclusions MMP3 may be an important substrate involved in wound healing. DPSCs may participate in the processes of wound repairing via high expression of MMP3.