Beta-cell responses to oxidative stress and Type 1 diabetes

1型糖尿病(T1D)是一种自身免疫性疾病，由于产生活性氧(ROS)、促炎性细胞因子/趋化因子和T细胞效应分子而导致胰腺β细胞的破坏。最近的证据表明，β细胞功能障碍也是T1D发病机制中的一个活跃参与者。我们将比较倾向于T1D的非肥胖糖尿病(NOD)小鼠和抵抗T1D的Ncf1m1J小鼠无法产生NADPH氧化酶(NOX)衍生的超氧化物的胰腺β细胞功能特性的变化。我们将研究NOD.Ncf1m1J小鼠中ROS的缺失如何调节β细胞的功能识别、与免疫细胞的相互作用以及T1D的延迟。为了证实我们的小鼠遗传模型，我们将检测用一种药理锰金属卟啉抗氧化剂与人类胰岛治疗后的胰腺b细胞反应。我们的主要假设是，ROS的减少将保留或增强β细胞的功能特性，如T1D倾向于NOD小鼠和人类胰岛的转录信号和胰岛素分泌所定义的那样。为了解决这一假设，将定义以下独立和相互关联的目标：(1)定义ROS的遗传消融如何保留β细胞的功能特性。(2)确定ROS缺失是否可降低胰腺β细胞介导的炎症反应。(3)确定抗氧化剂处理是否保留了小鼠和人β-细胞的功能。从我们的研究中获得的见解将增加我们对糖尿病病因的理解，并可能指出未来使用抗氧化剂化合物来保存和/或取代胰腺β细胞的功能的策略。

Type 1 diabetes (T1D) is an autoimmune disease resulting in pancreatic β-cell destruction due to the generation of reactive oxygen species (ROS), proinflammatory cytokines/chemokines, and T cell effector molecules. Recent evidence has shown that β-cell dysfunction is also an activate participant in T1D pathogenesis. We will compare pancreatic β-cell functional identity changes that occur with T1D-prone Non-obese Diabetic (NOD) mice with T1D-resistant NOD.Ncf1m1J mice unable to generate NADPH oxidase (NOX)-derived superoxide. We will examine how the absence of ROS in NOD.Ncf1m1J mice can regulate β-cell functional identity, interactions with immune cells, and delay in T1D. To corroborate our genetic mouse models, we will examine pancreatic b-cell responses following treatment with a pharmacological manganese metalloporphyrin antioxidant with human islets. Our overarching hypothesis is that reduction of ROS will preserve or enhance β-cell functional identity, as defined by transcriptional signatures and insulin secretion in T1D-prone NOD mice and human islets. To address this hypothesis, the following independent and interrelated aims will be defined: (1) Define how genetic ablation of ROS preserves β-cell functional identity. (2) Determine whether the absence of ROS can decrease pancreatic β-cell-mediated inflammatory responses. (3) Determine whether antioxidant treatment preserves the function of mouse and human β-cells. The insights gained from our studies will increase our understanding of diabetes etiology and may also point to future strategies employing antioxidant compounds to preserve and/or replace the function of pancreatic β-cells.