IRF6 in the Inflammatory Phase of Cutaneous Wound Healing

描述（由申请人提供）：先天免疫系统在炎症的发生和伤口愈合中起着至关重要的作用。在调节免疫反应的分子中，有干扰素调节因子（IRF）家族的转录因子。特别令人感兴趣的是IRF6，它是该家族的独特成员，也是伤口愈合的转录调节因子。事实上，Van der Woude综合征（VWS）是一种常染色体显性的由IRF6单倍功能不全引起的口面部裂综合征，与非综合征型口面部裂患者相比，VWS患者在矫正手术后更容易出现伤口并发症。Irf6缺失导致小鼠颅面、肢体和表皮异常，导致新生儿死亡。我们最近在肉芽中发现了强烈的Irf6信号

DESCRIPTION (provided by applicant): The innate immune system is of critical importance in the initiation of the inflammation and proper wound healing. Amongst molecules modulating the immune response are the transcription factors of the interferon regulatory factor (IRF) family. Of particular interest is IRF6, a unique member of this family and a transcriptional regulator of wound healing. Indeed, patients with Van der Woude syndrome (VWS), an autosomal dominant orofacial clefting syndrome caused by IRF6 haploinsufficiency, are more likely to have wound complications following corrective surgery than patients with a non-syndromic form of orofacial clefting. Loss of Irf6 results in craniofacial, limb and epidermal anomalies in the mouse, leading to neonatal mortality. We recently identified the presence of strong Irf6 signal in the granulation tissue of excisional wounds, particularly in macrophages and neutrophils. Preliminary data show that neutrophils from patients with VWS have impaired chemotaxis in vitro compared to controls. Furthermore, conditional removal of Irf6 in neutrophils and macrophages in a unique murine model results in a three fold reduction of cellular influx in a simple model of inflammation. Finally, cutaneous wound healing was severely impaired seven days post-wounding. Although the function of other IRF family members in innate immunity is well described, nothing is known about the function of IRF6 in innate immune cells and how it affects the inflammatory phase of cutaneous wound healing. The central hypothesis of this proposal is that Irf6 is required for proper macrophages and neutrophils function in vitro and in vivo in the context of wound healing. In specific aim #1, we will test the hypothesis that Irf6 regulates the secretion and migration of macrophages and neutrophils using luminex assay and live imaging of migration assays. In specific aim #2, we will directly test the hypothesis that expression of Irf6 in innate immune cells is necessary for the proper inflammatory phase of wound healing using our Irf6-conditional knockout mouse crossed with a lysosyme-driven Cre-recombinase mouse model. This proposal is innovative in that it extends the recently discovered role of Irf6 in epidermal morphogenesis and biology to innate immunity and cutaneous wound healing-a process that is highly significant from a clinical perspective, and a major cause of rising health-related costs. A the completion of these studies, we will have a better understanding of the contribution of Irf6 to the inflammatory process during cutaneous wound healing. Because continuous inflammation is a phenomenon leading to chronic wounds, chronic obstructive pulmonary disease, and is also implicated in cancer, new information will be obtained about a potential pathophysiological mechanism for these other common health concerns. PUBLIC HEALTH RELEVANCE: Relevance to Public Health This proposal will evaluate the role of Interferon Regulatory Factor 6 in inflammation in the context of cutaneous wound healing, a major cause of rising health-related costs. We expect to better understand how body closes holes and forms seams following injury. This work could have application to any inflammatory disease, including diabetes, autoimmune disorders, chronic wounds and cancer.