Localization of MMP and TIMP on the chronic skin wounds and possible application of MMP inhibitor

MMPs和MMPs在创面愈合过程中的作用和调节机制尚不完全清楚。缺乏慢性创面的实验模型是评价的主要问题。我们用压疮组织来评价MMPs的功能。在上皮化边缘，MMP2和MMP9在基底层至颗粒层之间的上皮细胞中表达上调。压疮中部未见MMPs和TIMPs。随着上皮化，创面成纤维细胞和创面巨噬细胞表达MMP2、MMP9和TIMP2。为了建立动物模型，我们评估了慢性肾功能衰竭大鼠和肉桂小鼠的伤口愈合情况。慢性肾功能衰竭大鼠未见切开创面和全层创面愈合延迟。在肉桂小鼠身上观察到伤口愈合的延迟。最后一项研究是观察皮肤伤口是否形成生物膜。在SD大鼠背部造成全层或部分层创面。将携带绿色荧光蛋白基因的铜绿假单胞菌(PAO1)悬液涂于创面。切取创面，进行组织学和免疫组织化学检查。罗丹明标记的刀豆蛋白A显示了生物膜的存在。我们证实在本实验模型中可以观察到铜绿假单胞菌在皮肤创面上形成生物膜，部分厚度的创面适合观察生物膜的形成。同时，一块标准化的背侧缺血瓣被提起并缝合。在皮瓣上形成了部分厚度的伤口。与非缺血对照相比，缺血区创面生物膜的形成程度明显减少。创面缺血在实验模型中不增加生物膜的形成。

The functions and regulations of MMPs and MMPs on the wound healing process are not fully understood. The lack of experimental models for chronic wounds is the main problem for the evaluation. We evaluated the functions of MMPs using pressure ulcer tissues. At the edge of epithelization, MMP2 and MMP9 are upregulated in the epithelial cells between basal layer to granular layers. In the middle area of pressure ulcer, MMPs and TIMPs are not found. Along with epithelization, wound fibroblast and wound macrophage expressed MMP2 and MMP9 and TIMP2. For the development of animal model, we evaluated wound healing in the chronic renal failure rat and cinnamon mouse. Delay of wound healing of incisional wound and full thickness wound was not observed in the chronic renal failure rat. Delay in the wound healing was observed in cinnamon mouse. The final study was to observe whether biofilm formation occurs on skin wounds. Full or partial thickness wounds were created on the backs of SD rats. Suspensions of P.aeruginosa (PAO1 carrying the gene encoding the green fluorescent protein) was applied on the wounded area. Wounds were harvested and processed for histology and immunohistochemistry. The presence of biofilm were indicated Rhodamine-conjugated concanavalin A. We confirmed biofilm formation by P.aeruginosa on skin wounds can observe in this experimental model, and partial thickness wounds were proper for to observe biofilm formation. Also, a standardized dorsal ischemic flap was lifted and sutured. Partial thickness wounds were created on the flap. The extent of biofilm formation was significantly diminished on the surface of ischemic wound compared with non-ischemic control. Wound ischemia in the experimental model does not increase the formation of biofilms.