Maturation of Normal & Sensitized Airway Contractility

正常成熟度

• 批准号: 7367035
• 负责人: THOMAS Miles MURPHY
• 金额: $ 34.08万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7367035
• 关键词: Address; Adolescent; Adult; Affect; Age; Amino Acids; Animal Model; Antigens; Asthma; Beginning of Life; Biological Models; Birth; Boxing; Calcium; Calmodulin; Cavia; Contractile Proteins; Cyclic AMP-Dependent Protein Kinases; Cytoskeleton; Desmin; Development; Early Intervention; Experimental Designs; Filament; G-Protein-Coupled Receptors; Generations; Genetic; Immune; Inflammation; Injection of therapeutic agent; Inositol; Intermediate Filament Proteins; Intermediate Filaments; Intervention; Life; Light; Live Birth; Measurement; Mechanics; Mediating; Microscopic; Modeling; Muscle; Muscle Cells; Myosin Heavy Chains; Myosin Light Chain Kinase; Myosin Light Chains; Neonatal; Newborn Infant; Numbers; Oranges; Ovalbumin; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Play; Post-Transcriptional Regulation; Prevalence; Principal Investigator; Property; Protein Dephosphorylation; Protein Isoforms; Protein phosphatase; Proteins; Publications; Regulation; Research Personnel; Resistance; Role; Signal Transduction; Smooth Muscle; Testing; Vimentin; Week; airway hyperresponsiveness; base; day; early childhood; fetal; genetic regulatory protein; human tissue; inorganic phosphate; myosin phosphatase; neonate; novel; p21 activated kinase; prevent; programs; receptor; release of sequestered calcium ion into cytoplasm; research study; respiratory smooth muscle; vimentin kinase

Asthma prevalence is greater during childhood and early airway insults may affect the expression of asthma in adults. Airway reactivity in several species increases from minimal during fetal life and birth to a substantial level in a few days to weeks. We have discovered key and parallel roles for the phosphorylation of myosin light chain (MLC20) by myosin light chain kinase (MLCK) and the reduced mechanical opposition to shortening in the normally augmented shortening of airway smooth muscle (ASM) in 3 week old juvenile guinea pigs and immune-augmented shortening in adults following neonatal sensitization. Maximal force generation is unchanged with maturation and following sensitization. Based on our results: ASM shortening declines from juveniles to adulthood while the internal resistance to shortening Rsi and the passive stiffness of the muscle increase. MLCK levels and the phosphorylation of MLC20 decline in parallel. In preliminary experiments neonatal sensitization increases ASM shortening and MLCK content and decreases the Rsi of ADULT ASM only. In this application, these findings are integrated into a novel hypothetical mechanism that relfects a NEW PARADIGM for augmented smooth muscle shortening in normal non-neonatal juveniles and in adults previously sensitized as neonates. This paradigm suggests that changes in the cytoskeleton matrix to facilitate shortening are of similar importance to those factors that facilitate the phosphorylation of myosin light chain. It also suggests that airway hyperresponsiveness may have its origins (and thus the need for intervention) early in life. The specific aims are: 1. To determine whether or not increased MLCK content plays a key regulatory role in the increased ASM shortening in normal juvenile trachealis and adults sensitized as newborns. To determine whether or not the increased content of the fast isoforms SM1B and SM2B of myosin heavy chain increases ASM shortening. 2. To determine the genetic and protein regulation of MLCK expression with development and following neonatal sensitization. 3. To determine whether the increased shortening in normal juvenile trachealis and in adults sensitized as newborns is associated with passive mechanical properties that reduce the internal resistance to shortening. To determine whether the content/phosphorylation of the intermediate filaments desmin and vimentin plays a role in the internal resistance to shortening of airway smooth muscle.

儿童时期哮喘患病率较高，早期气道损伤可能会影响哮喘的表现 在成人中。一些物种的气道反应性从胎儿生命和出生期间的最低水平增加到 在几天到几周内达到显着水平。我们发现了磷酸化的关键和平行作用 肌球蛋白轻链激酶（MLCK）对肌球蛋白轻链（MLC20）的影响以及机械阻力的减少 3 周龄青少年气道平滑肌 (ASM) 正常缩短的缩短 豚鼠和新生儿致敏后成人的免疫增强缩短。最大力 随着成熟和随后的敏化，代数不会发生变化。根据我们的结果：ASM 缩短 从幼年到成年，内阻Rsi缩短，被动刚度下降 的肌肉增加。 MLCK 水平和 MLC20 磷酸化同时下降。在初步 实验新生儿致敏增加了 ASM 缩短和 MLCK 含量，并降低了 Rsi 仅限成人 ASM。在此应用中，这些发现被整合到一种新颖的假设机制中，该机制 反映了一种在正常非新生儿幼体中增强平滑肌缩短的新范式 在以前作为新生儿过敏的成年人中。这个范式表明细胞骨架的变化 促进缩短的基质与促进磷酸化的那些因素具有相似的重要性 肌球蛋白轻链。它还表明气道高反应性可能有其起源（因此 需要在生命早期进行干预。具体目的是： 1. 判断MLCK是否增加 含量在正常幼年气管和成人的 ASM 缩短增加中起着关键的调节作用 新生儿时就敏感。确定快速异构体 SM1B 和 SM1B 的含量是否增加 肌球蛋白重链的 SM2B 增加 ASM 缩短。 2. 确定遗传和蛋白质调控 MLCK 表达随发育和新生儿致敏的变化。 3. 判断是否 正常幼年气管和新生儿过敏的成人气管缩短增加与 被动机械性能，降低内部短路阻力。来判断是否 中间丝结蛋白和波形蛋白的含量/磷酸化在内部发挥作用 抵抗气道平滑肌的缩短。