The role of SerpinB2 in insulin resistance and inflammation

SerpinB2 在胰岛素抵抗和炎症中的作用

• 批准号: 10615780
• 负责人: Partha Dutta
• 金额: $ 46.38万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10615780
• 关键词: Adipose tissue; Age; Alteplase; Anti-Inflammatory Agents; Apoptosis; Apoptotic; Binding; Body mass index; Caspase; Cells; Data; Diabetes Mellitus; Disease; Exhibits; Frequencies; GKLF protein; Genetic Transcription; Glucose Clamp; Hematopoietic; Human; Hyperinsulinism; In Vitro; Individual; Inflammation; Inflammatory; Insulin Resistance; Interferon Gamma Receptor Complex; Interferon Type II; Interleukin-1 beta; Interleukin-13; Interleukin-4; Knowledge; MAPK3 gene; Macrophage; Malignant Neoplasms; Measures; Mediating; Metabolic syndrome; Mitogen-Activated Protein Kinases; Molecular; Mus; Nematode infections; Obese Mice; Obesity; Pathogenesis; Pathologic; Patients; Plasminogen Activator Inhibitor 1; Plasminogen Activator Inhibitor 2; Play; Prevention; Process; Production; Proteins; Role; Serine Proteinase Inhibitors; Small Interfering RNA; Source; T-Lymphocyte; TNF gene; Testing; Thinness; Tissues; Urokinase; Visceral; Wild Type Mouse; cytokine; diabetic patient; drug development; experimental study; extracellular signal-regulated kinase 4; glucose tolerance; impaired glucose tolerance; improved; in vivo; inhibitor; insulin sensitivity; insulin tolerance; monocyte; nanoparticle; non-diabetic; overexpression; promoter; receptor; transcription factor; transcriptome; transglutaminase 2

Project Summary/ Abstract: Plasminogen activator inhibitor type 1 (PAI-1) and type 2 (PAI-2) are serine protease inhibitors of tissue plasminogen activator and urokinase. PAI-2, which is encoded by SerpinB2, has been shown to be critical to the pathogenesis of different diseases including cancer and nematode infection. However, its role in obesity- associated insulin resistance is not known. Our preliminary experiments revealed that diabetic patients harbored significantly reduced number of SerpinB2+ cells in omental adipose tissue compared to non-diabetic individuals. Moreover, we observed an inverse correlation between the frequency of SerpinB2+ cells and body mass index in patients, suggesting a protective role of SerpinB2 in diabetes. Consistently, SerpinB2-deficient mice exhibited impaired glucose tolerance. Among all hematopoietic cells in visceral adipose tissue (VAT), only resident macrophages expressed detectable and high amount of SerpinB2. This macrophage subset had significantly reduced SerpinB2 expression in obese humans and mice compared to lean control. Furthermore, VAT of obese humans and mice contained diminished number of resident macrophages due to their high apoptosis, which is in line with the well-known anti-apoptotic role of SerpinB2. Additionally, we found that SerpinB2 is essential for the production of anti-inflammatory cytokines, such as IL-4 and IL-13, by VAT resident macrophages. These cytokines are crucial for maintaining insulin sensitivity. Based on these observations, we hypothesize that reduced SerpinB2 expression in obesity triggers VAT resident macrophage apoptosis, increases inflammation and promotes insulin resistance. We will test this hypothesis in two specific aims. Aim. 1. To determine the role of SerpinB2 in insulin resistance, we will use 3-fold approaches: a) SerpinB2-/- mice, b) macrophage-specific SerpinB2-deficient mice (LysMcre/+ SerpinB2fl/fl) and c) SerpinB2 silencing in VAT macrophages in vivo in wild type mice using siRNA formulated in lipidoid nanoparticles. Furthermore, we will determine if T cell-derived IFN-γ in obesity decreases SerpinB2 expression. We will also test if SerpinB2- mediated production of anti-inflammatory cytokines depends on Kruppel-like factor 4 (Klf4) and mitogen activated protein kinase (MAPK) activators ERK1/2. Aim. 2. We will investigate the molecular mechanisms of the prevention of apoptosis by SerpinB2. Our preliminary data demonstrated that SerpinB2-deficient macrophages contained diminished levels of transglutaminase 2 (TG2), a known modulator of caspase. Additionally, we observed that SerpinB2 directly binds to TG2. To determine if anti-apoptotic effect of SerpinB2 is TG2-mediated, we will overexpress SerpinB2 in TG2-deficient macrophages and use specific TG2 inhibitors.

项目摘要/摘要： 纤溶酶原激活物抑制剂1型（PAI-1）和2型（PAI-2）是组织的串行蛋白抑制剂 纤溶酶原激活剂和尿激酶。由serpinb2编码的PAI-2已被证明对 包括癌症和线虫感染在内的不同疾病的发病机理。但是，它在肥胖症中的作用 - 相关的胰岛素抵抗尚不清楚。我们的初步实验表明糖尿病患者 与非糖尿病人相比 个人。此外，我们观察到serpinb2+细胞和身体的频率之间存在反相关性 患者的质量指数表明SERPINB2在糖尿病中的作用受到保护。一贯，serpinb2缺乏效率 小鼠暴露于葡萄糖耐受性受损。在内脏脂肪组织（VAT）中的所有造血细胞中，仅 居民巨噬细胞表示可检测到的serpinb2。这个巨噬细胞子集有 与瘦肉对照相比，肥胖人和小鼠的SERPINB2表达显着降低。此外， 肥胖人类和小鼠的桶中包含巨噬细胞数量减少，原因很高 凋亡，与SERPINB2的众所周知的抗凋亡作用一致。此外，我们发现 SERPINB2对于增值税居民的产生抗炎细胞因子（例如IL-4和IL-13）至关重要 巨噬细胞。这些细胞因子对于维持胰岛素敏感性至关重要。基于这些观察，我们 假设肥胖症中serpinb2的表达降低，触发了增值税居民巨噬细胞凋亡， 增加影响并促进胰岛素抵抗。我们将以两个具体的目的来检验这一假设。目的。 1。确定serpinb2在胰岛素耐药性中的作用，我们将使用3倍方法：a）serpinb2 - / - 小鼠，b） 巨噬细胞特异性的serpinb2缺乏小鼠（lysmcre/+ serpinb2fl/fl）和c）serpinb2在增值税中沉默 巨噬细胞在野生型小鼠的体内使用脂肪纳米颗粒中配制的siRNA。此外，我们会的 确定肥胖症中T细胞衍生的IFN-γ是否会降低SERPINB2的表达。我们还将测试是否serpinb2-- 抗炎细胞因子的介导的产生取决于Kruppel样因子4（KLF4）和有丝分裂原 活化的蛋白激酶（MAPK）活化剂ERK1/2。目的。 2。我们将研究分子机制 SERPINB2预防凋亡。我们的初步数据表明SERPINB2缺乏效率 巨噬细胞包含caspase的已知调节剂的转谷氨酰胺2（TG2）的水平降低。 此外，我们观察到SERPINB2直接与TG2结合。确定serpinb2的抗凋亡作用是否 是TG2介导的，我们将在TG2缺乏巨噬细胞中过表达SERPINB2并使用特定的TG2抑制剂。