Neutrophils Express Tumor Necrosis Factor-α During Mouse Skin Wound Healing

The expression pattern of tumor necrosis factor-α (TNF-α) mRNA and protein was examined in vivo in experimental mouse skin wounds by in situ hybridization and immunohistochemistry. TNF-α mRNA and protein is detected in a distinct layer of mainly neutrophils subadjacent to the wound clot. The layer of TNF-α-positive cells extends from the margin of the advancing epithelial outgrowth to the opposing one. By in situ hybridization the TNF-α mRNA is detectable 12 h after wounding; the signal peaks after 72 h and remains visible up to at least 120 h after wounding. TNF-α mRNA could not be detected in the normal skin or in 5-hour-old wounds, lmmunohistochemical staining for TNF-α and macrophages on adjacent sections confirms that the main part of TNF-α-positive cells are polymorphonuclear neutrophils and shows that most of the cells located just beneath the layer of TNF-α-positive neutrophils are macrophages with weak TNF-α immunoreactivity. The data reported here show that neutrophils serve as an important source of TNF-α during healing of mouse skin wounds. We suggest that this specific expression of TNF-α is related to the process of re-epithelialization

Neutralisation of uPA with a Monoclonal Antibody Reduces Plasmin Formation and Delays Skin Wound Healing in tPA-Deficient Mice

Background: Proteolytic degradation by plasmin and metalloproteinases is essential for epidermal regeneration in skin wound healing. Plasminogen deficient mice have severely delayed wound closure as have mice simultaneously lacking the two plasminogen activators, urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). In contrast, individual genetic deficiencies in either uPA or tPA lead to wound healing kinetics with no or only slightly delayed closure of skin wounds. Methodology/Principal Findings: To evaluate the therapeutic potential in vivo of a murine neutralizing antibody directed against mouse uPA we investigated the efficacy in skin wound healing of tPA-deficient mice. Systemic administration of the anti-mouse uPA monoclonal antibody, mU1, to tPA-deficient mice caused a dose-dependent delay of skin wound closure almost similar to the delayed kinetics observed in uPA;tPA double-deficient mice. Analysis of wound extracts showed diminished levels of plasmin in the mU1-treated tPA-deficent mice. Immunohistochemistry revealed that fibrin accumulated in the wounds of such mU1-treated tPA-deficent mice and that keratinocyte tongues were aberrant. Together these abnormalities lead to compromised epidermal closure. Conclusions/Significance: Our findings demonstrate that inhibition of uPA activity with a monoclonal antibody in adult tPA-deficient mice mimics the effect of simultaneous genetic ablation of uPA and tPA. Thus, application of the murin

Immunolymphoscintigraphy for Metastatic Sentinel Nodes: Test of a Model

Aim. To develop a method and obtain proof-of-principle for immunolymphoscintigraphy for identification of metastatic sentinel nodes. Methods. We selected one of four tumour-specific antibodies against human breast cancer and investigated (1), in immune-deficient (nude) mice with xenograft human breast cancer expressing the antigen if specific binding of the intratumorally injected, radioactively labelled, monoclonal antibody could be scintigraphically visualized, and (2) transportation to and retention in regional lymph nodes of the radioactively labelled antibody after subcutaneous injection in healthy rabbits. Results and Conclusion. Our paper suggests the theoretical possibility of a model of dual isotope immuno-lymphoscintigraphy for noninvasive, preoperative, malignant sentinel node imaging