IL-6-mediated Jak2/Stat3 signaling and Brain Development

IL-6 介导的 Jak2/Stat3 信号传导与大脑发育

• 批准号: 7985709
• 负责人: Jun Tan
• 金额: $ 22.05万
• 依托单位: UNIVERSITY OF SOUTH FLORIDA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7985709
• 关键词: Adult; Adult Children; Affect; Anti-Inflammatory Agents; Anti-inflammatory; Antibodies; Attenuated; Autistic Disorder; Behavior; Behavioral; Bioflavonoid; Blood; Brain; Cell Nucleus; Cells; Chemicals; Child; Citrus; Clinical Research; Clinical Trials; Data; Defect; Development; Diet; Diosmin; Event; Fetus; Figs - dietary; Folate; Food; Foundations; Functional disorder; Future; Human; Immune; Immune system; Immunohistochemistry; Impairment; Infection; Inflammatory; Injection of therapeutic agent; Interleukin-6; JAK2 gene; Janus kinase 2; Lead; Light; Luteolin; Mediating; Molecular; Mothers; Mus; Neural Tube Defects; Neurons; Newborn Infant; Oral; Oral Administration; Pathway interactions; Phosphorylation; Phosphotransferases; Play; Primary Cell Cultures; Principal Investigator; Problem behavior; Process; Production; Prophylactic treatment; Proteins; Qualifying; Recombinants; Regulation; Reporting; Risk; Role; Signal Pathway; Signal Transduction; Social Behavior; Social Interaction; Stat3 protein; Supplementation; Testing; Time; Validation; Vision; Western Blotting; Work; attenuation; behavior test; behavioral impairment; brain tissue; cytokine; fetal; flavanoid; immune activation; improved; in utero; in vivo; inhibitor/antagonist; maternal serum; neurodevelopment; offspring; pregnant; prenatal; programs; public health relevance; therapeutic target; young adult

DESCRIPTION (provided by applicant): It has been suggested that maternal immune activation (MIA) by a range of infections can affect fetal brain development and thus behavior of young and adult offspring. Most recently, Smith and colleagues (2007) reported that increased IL-6 in the maternal serum plays a key role in altering fetal brain development and impairing behaviors in social interactions in the offspring, all the way into adulthood. Interestingly, these effects could be attenuated by blocking IL-6, using anti-IL-6 antibody and/or mice deficient in IL-6. Our preliminary studies showed that the citrus bioflavonoid, luteolin, inhibits neuronal JAK2/STAT3 phosphorylation in both murine neuron-like (N2a) cells and primary cultured neuronal cells challenged with mouse recombinant IL-6 protein. As a validation of these findings, we next examined the effects of a STAT3 inhibitor (S31-201) and diosmin, a flavanoid structurally similar to luteolin, on JAK2/STAT3 signaling in vivo. When either agent was applied to pregnant mice with an injection of IL-6, JAK2/STAT3 phosphorylation and pro-inflammatory cytokines were both significantly reduced in brain homogenates from newborn mice. We further showed that diosmin administered orally in chow [10 mg/kg/day (0.005% diosmin in NIH31 control chow)] significantly changes behavioral deficits in social interaction and reduces pro-inflammatory cytokines in brain tissues of IL-6/MIA adult offspring. We also found that diosmin reduces the CNS levels in pro- inflammatory cytokines consistent with JAK2/STAT3 signal pathway inhibition. It's well known that the risk of altering fetal brain development is associated with prenatal maternal infection, specifically, with cytokine- related inflammatory events in the CNS. Presumably, diosmin molecular inhibition of JAK2/STAT3 pathway could be involved in improving abnormal social interaction in IL-6/MIA adulthood offspring. In this proposal, we will examine whether or not JAK2/STAT3 signal pathway activation could be specifically involved in brain histological abnormalities in IL-6-induced MIA (presumably resulting in development of abnormal behavior in adult offspring that mimics features of autism). In addition, we intend to fully characterize and qualify diosmin's potential effect on improving abnormal, autistic like social behaviors in IL-6/MIA offspring in adulthood via its attenuation of the JAK2/STAT3 signal pathway. These studies could lay the foundation for autism clinical trials with diosmin diet supplementation in the near future. PUBLIC HEALTH RELEVANCE: It has been suggested that activation of pregnant mother's immune system by infections can affect the brain of the developing fetus and thus behavior of young and adult offspring. Most recently, it was reported that increased IL-6 (a chemical messenger of the immune system) in the mother's blood plays a key role in altering fetal brain development and impairing behaviors in social interactions in the offspring. Interestingly, these effects could be avoided by blocking IL-6 chemically with an antibody or by genetically altering mice so they are deficient in IL-6. Our preliminary studies showed that the natural citrus molecule, luteolin, inhibits the signaling mechanism (JAK2/STAT3) in neurons which carries IL-6's signal to the nucleus. This occurred in neuron-like (N2a) cells and neurons removed and cultured from mouse brains and then challenged with mouse IL-6 protein. As a validation of these findings, we next examined the effects of an artificial STAT3 inhibitor and diosmin, a structurally similar natural citrus molecule to luteolin, on JAK2/STAT3 signaling in mice. When either agent was applied to pregnant mice with an injection of IL-6 to activate the mother's immune system JAK2/STAT3 activation and inflammatory cytokines were both significantly reduced in the brains of the newborn mice. We further showed that diosmin given orally mixed in mouse food significantly improves behavioral problems in social interaction and reduces inflammatory cytokines in brain tissues of the offspring of the IL-6 injected mothers. Further, diosmin specifically reduces the brain inflammatory cytokines triggered by JAK2/STAT3 signaling. Presumably, diosmin inhibition of JAK2/STAT3 pathway could be involved in improving abnormal social interaction in offspring of IL-6 injected mothers. In this proposal, we will examine whether or not JAK2/STAT3 signal pathway activation could be specifically involved in brain structural abnormalities in IL-6-induced activation of the maternal immune system (presumably resulting in development of abnormal behavior in adult offspring that mimics features of autism). In addition, we intend to fully test diosmin's potential effect on improving abnormal, autistic like behaviors of offspring of IL-6 immune activated mothers by the JAK2/STAT3 signal pathway blocking with diosmin. These studies could lay the foundation for diosmin as a prenatal supplement in at-risk mothers to avoid autism development in their children, much like folate is currently in use to avoid neural tube defects.

描述（由申请人提供）：有人提出，一系列感染引起的母体免疫激活（MIA）会影响胎儿大脑发育，从而影响幼年和成年后代的行为。最近，Smith 及其同事 (2007) 报告称，母体血清中 IL-6 的增加在改变胎儿大脑发育和损害后代社交互动行为方面发挥着关键作用，一直到成年。有趣的是，这些效应可以通过使用抗 IL-6 抗体和/或缺乏 IL-6 的小鼠阻断 IL-6 来减弱。我们的初步研究表明，柑橘生物类黄酮、木犀草素可抑制小鼠神经元样 (N2a) 细胞和用小鼠重组 IL-6 蛋白攻击的原代培养神经元细胞中的神经元 JAK2/STAT3 磷酸化。为了验证这些发现，我们接下来检查了 STAT3 抑制剂 (S31-201) 和地奥司明（一种与木犀草素结构相似的黄酮类化合物）对体内 JAK2/STAT3 信号传导的影响。当将任一药物应用于注射 IL-6 的怀孕小鼠时，新生小鼠脑匀浆中的 JAK2/STAT3 磷酸化和促炎细胞因子均显着降低。我们进一步表明，在饲料中口服地奥司明[10 mg/kg/天（NIH31对照饲料中0.005%地奥司明）]显着改变了社交互动中的行为缺陷，并减少了IL-6/MIA成年后代脑组织中的促炎细胞因子。我们还发现地奥司明降低 CNS 中促炎细胞因子的水平，这与 JAK2/STAT3 信号通路抑制一致。众所周知，改变胎儿大脑发育的风险与产前母体感染有关，特别是与中枢神经系统中细胞因子相关的炎症事件有关。据推测，地奥司明对 JAK2/STAT3 通路的分子抑制可能参与改善 IL-6/MIA 成年后代的异常社交互动。 在本提案中，我们将检查 JAK2/STAT3 信号通路激活是否可能专门参与 IL-6 诱导的 MIA 中的脑组织学异常（可能导致成年后代出现模仿自闭症特征的异常行为）。此外，我们打算充分表征和鉴定地奥司明通过减弱 JAK2/STAT3 信号通路对改善 IL-6/MIA 后代成年期异常、自闭症样社会行为的潜在影响。这些研究可以为不久的将来通过饮食补充地奥司明的自闭症临床试验奠定基础。 公共卫生相关性：有人认为，感染激活孕妇的免疫系统可能会影响发育中胎儿的大脑，从而影响年轻和成年后代的行为。最近，据报道，母亲血液中 IL-6（免疫系统的化学信使）的增加在改变胎儿大脑发育和损害后代社交互动行为方面发挥着关键作用。有趣的是，这些影响可以通过用抗体化学阻断 IL-6 或通过基因改造小鼠使其缺乏 IL-6 来避免。我们的初步研究表明，天然柑橘分子木犀草素可抑制神经元中将 IL-6 信号传递至细胞核的信号传导机制 (JAK2/STAT3)。这种情况发生在神经元样 (N2a) 细胞和从小鼠大脑中取出并培养的神经元中，然后用小鼠 IL-6 蛋白进行攻击。为了验证这些发现，我们接下来检查了人工 STAT3 抑制剂和地奥司明（一种与木犀草素结构相似的天然柑橘分子）对小鼠 JAK2/STAT3 信号传导的影响。当将任一药物应用于怀孕小鼠并注射 IL-6 以激活母亲的免疫系统时，新生小鼠大脑中的 JAK2/STAT3 激活和炎症细胞因子均显着减少。我们进一步表明，在小鼠食物中混合口服地奥司明可显着改善社交互动中的行为问题，并减少注射 IL-6 的母亲后代脑组织中的炎症细胞因子。此外，地奥司明特异性降低由 JAK2/STAT3 信号传导触发的脑炎症细胞因子。据推测，地奥司明对 JAK2/STAT3 通路的抑制可能与改善注射 IL-6 的母亲的后代的异常社交互动有关。在本提案中，我们将检查 JAK2/STAT3 信号通路激活是否可能专门参与 IL-6 诱导的母体免疫系统激活中的大脑结构异常（可能导致成年后代出现模仿自闭症特征的异常行为）。此外，我们打算通过地奥司明阻断JAK2/STAT3信号通路来充分测试地奥司明对改善IL-6免疫激活母亲的后代异常、自闭症样行为的潜在作用。这些研究可以为地奥司明作为高危母亲的产前补充剂，以避免孩子患自闭症奠定基础，就像目前使用叶酸来避免神经管缺陷一样。