Src and its Multiple Adverse Roles Targeted (SMART) in Acute Pancreatitis

描述（由申请人提供）：急性胰腺炎（AP）在严重时可能致命，并且发病率正在增加，导致显著的医疗保健负担和成本。目前，除了支持性治疗外，AP没有特定的治疗方法。不幸的是，靶向单个机械上重要的步骤的常规策略在临床上并不成功，这可能是由于AP中同时激活的多种有害信号传导途径。此外，像肥胖这样的修饰剂会使引发剂的结果恶化，否则可能导致轻度AP，增加了额外的复杂性。因此，我们的目的是确定一个目标，将参与多种机制的AP启动和肥胖期间的脂毒性加重。基于其多重作用，我们将c-Src确定为这样的靶点，其也与人类疾病密切相关。初步资料：我们发现证据表明，在AP启动过程中，c-Src参与了许多层面。这些包括c-Src依赖的高尔基体的顺行延伸，通过高尔基体运输糜蛋白酶，胰蛋白酶原激活，F-肌动蛋白重塑，胰腺酶的基底外侧释放和腺泡细胞死亡。强有力的证据表明，不饱和脂肪酸（乌法）在肥胖期间AP的脂毒性加重中起作用。我们发现了c-Src参与脂毒性加重的证据。这包括脂肪坏死中c-Src表达增加，与脂肪组织中胰脂肪酶量增加相关，沿着脂解减少，脂毒性腺泡损伤，以及c-Src抑制剂改善严重AP。这进一步得到了c-Src表达的支持，c-Src表达导致脂滴的损失，沿着3 T3 LI细胞中脂肪酶量的增加，并且在人脂肪坏死中注意到Src活化并响应于亚油酸（LA）。因此，我们假设c-Src是AP的治疗靶点，因为它参与AP启动及其脂毒性加重过程中的多个步骤。建议：我们建议研究c-Src在AP的发生和脂毒性加重中的多重作用。这些包括其在调节通过高尔基体的货物运输、胰蛋白酶原激活基底外侧渗漏和腺泡细胞死亡中的作用。基于初步数据显示其在AP脂毒性加重中的多种作用，我们还计划探索c-Src在脂毒性介质（例如乌法）中的作用，产生以及c-Src如何进一步调节腺泡和炎症对这些脂毒性介质的反应。这包括c-Src在腺泡和炎性细胞死亡中的作用，以及在 腺泡细胞、脂肪细胞产生炎症介质。最后，我们将研究基因或药物抑制c-Src是否能改善轻度和肥胖相关致死性AP的结局。这些新的研究可以打开一个新的多模式的治疗前沿AP定义的作用，一个单一的可耐受的治疗靶点，即c-Src（目前有药物批准用于人类使用）在多个不同的步骤在AP的启动和脂毒性加重。

DESCRIPTION (provided by applicant): Acute Pancreatitis (AP) is potentially lethal when severe and is increasing in incidence, resulting in significant health care burden and costs. Currently AP has no specific therapy apart from supportive care. The conventional strategy of targeting a single mechanistically important step has unfortunately not been successful on the clinical front, likely due to the multiple deleterious signaling pathways simultaneously activated in AP. Additionally, modifiers like obesity worsen outcomes from an initiator which may otherwise cause mild AP, adding an additional layer of complexity. We thus aimed at identifying a target that would be involved in multiple mechanisms of AP initiation and its lipotoxic exacerbation during obesity. Based on its multiple roles, we identified c-Src as such a target, which also is pharmacologically relevant to human disease. PRELIMINARY DATA: We found evidence of c-Src's involvement at numerous levels during AP initiation. These included c-Src dependent antegrade extension of the Golgi, trafficking of chymotrypsin through the Golgi, trypsinogen activation, F-actin remodeling, basolateral release of pancreatic enzymes and acinar cell death. Strong evidence implicates unsaturated fatty acids (UFA) in the lipotoxic exacerbation of AP during obesity. We found proof of c-Src's involvement in this lipotoxic exacerbation. This included increased expression of c-Src in fat necrosis, associated with increased pancreatic lipase amounts in adipose tissue, along with a reduction in lipolysis, lipotoxic acinar injury, and improvement in severe AP by inhibitors of c-Src. This is further supported by c-Src expression causing a loss of lipid droplets, along with increasing lipase amounts in 3T3LI cells, and Src activation being noted in human fat necrosis and in response to linoleic acid (LA). We therefore hypothesize that c-Src is a therapeutic target in AP since it is involved in multiple steps during AP initiation and its lipotoxic exacerbation. PROPOSAL: We propose to study the multiple roles of c-Src in the initiation and lipotoxic exacerbation of AP. These include its role in regulating trafficking of cargo through the Golgi, trypsinogen activation basolateral leakage and acinar cell death. Based on preliminary data showing its multiple roles in lipotoxic exacerbation of AP, we also plan to explore the role of c-Src in lipotoxic mediator (e.g. UFA), generation and how c-Src further regulates the acinar and inflammatory response to these lipotoxic mediators. This includes c-Src's role in acinar and inflammatory cell death, and in the generation of inflammatory mediators by acinar cells, adipocytes. Lastly, we will study whether genetic or pharmacologic inhibition of c-Src improves outcomes in both mild and obesity associated lethal AP. These novel studies could open a new multimodal therapeutic frontier for AP by defining the role of a single pharmacologically amenable therapeutic target, i.e. c-Src (for which there are drugs currently approved for human use) in multiple distinct steps during the initiation and lipotoxic exacerbation of AP.