Connexin-Mediated Hemichannel Activity in Experimental Periodontitis

描述（由申请人提供）：先天免疫系统对入侵的病原体提供立即的非特异性反应。粘膜角质形成细胞之间以及与近端免疫细胞之间的通信是这种应答的基础。该项目的长期目标是通过连接蛋白半通道和间隙连接来表征口腔组织中的细胞间通讯，以设计用于粘膜组织感染的新治疗方法。连接蛋白是形成细胞间通道的蛋白质，其集中在间隙连接中。细胞间的通讯可以通过细胞间缝隙连接通道的打开来启动。此外，连接蛋白半通道（未对接通道）可以促进细胞溶质生物活性介质的转移、释放或摄取-有效地提供细胞之间经由细胞外途径的通信。这些介质可以向近端上皮细胞和免疫细胞发出侵入性病原体存在的信号。然而，随着牙龈卟啉单胞菌渗透牙周组织，控制炎症的细胞间通讯可能变得具有破坏性。在初步实验中，我们已经表明，牙龈卟啉单胞菌增强口腔上皮细胞的半通道开放，对细胞上方的流体运动（机械刺激）的立即反应，口腔角质形成细胞主要表达连接蛋白43（Cx43）。因此，我们假设牙龈卟啉单胞菌通过TLR增强粘膜上皮细胞的半通道开放，增加炎症和牙周病的严重程度。为了验证这个假设，我们将：1。表征Cx43在牙龈卟啉单胞菌增强牙龈上皮细胞中半通道和间隙连接通讯中的作用。2.确定半通道开放是否是TLR参与信号传导的结果。3.使用小鼠牙周炎模型显示Cx43参与牙周病的进展[严重程度增加]。最终了解细胞如何相互通信将使我们能够修改释放的生物活性介质和/或创造改变信号的新方法，这将导致粘膜感染的新治疗方法。 公共卫生相关性：所有细胞都可以通过其外膜内的通道与彼此及其环境进行通信。这项研究旨在了解在牙齿周围组织中引起疾病的细菌是否劫持了细胞之间的通信，从而增加炎症和疾病的严重程度。了解细菌和细胞如何交流将使我们能够创造新的粘膜感染治疗方法。

DESCRIPTION (provided by applicant): The innate immune system provides an immediate nonspecific response to invading pathogens. Communication among mucosal keratinocytes and with proximal immune cells is fundamental to such a response. The long-term goal of this project is to characterize cell-to-cell communication in oral tissues through connexin hemichannels and gap junctions in order to design new treatments for infection of mucosal tissues. Connexins are proteins that form cell-to-cell channels, which are concentrated within gap junctions. Cell-to-cell communication can be initiated by the opening of gap junction channels between cells. In addition, connexin hemichannels (undocked channels) can promote the transfer, release or uptake of cytosolic bioactive mediators - effectively providing for communication between cells via an extracellular pathway. These mediators could signal proximal epithelial and immune cells to the presence of invasive pathogens. However as P. gingivalis penetrates periodontal tissue, cell-to-cell communication controlling inflammation may become destructive. In preliminary experiments, we have shown that Porphyromonas gingivalis potentiates hemichannel opening in oral epithelial cells, an immediate response to fluid movement above the cells (mechanical stimulation), and oral keratinocytes express predominately connexin 43 (Cx43). We hypothesize, therefore, that P. gingivalis potentiates hemichannel opening in mucosal epithelial cells through TLRs, increasing inflammation and the severity of periodontal disease. To test this hypothesis we will: 1. Characterize the role of Cx43 in P. gingivalis potentiation of hemichannel and gap junction communication in gingival epithelial cells. 2. Determine whether hemichannel opening is a result of signaling from engagement of TLRs. 3. Show that Cx43 is involved in the progression [increasing severity] of periodontal disease using a mouse model of periodontitis. Ultimately knowing how cells communicate with each other will allow us to modify released bioactive mediators and/or create novel ways of altering the signal, which will lead to novel treatments for mucosal infection. PUBLIC HEALTH RELEVANCE: All cells can communicate with each other and their environment through channels within their outer membrane. This study seeks to understand if bacteria that cause disease in the tissue around the teeth hijack the communication between cells increasing inflammation and the severity of disease. Knowing how bacteria and cells communicate will allow us to create novel treatments for mucosal infections.