Function of Gut Peptides in Isolated Gut Muscle Cells

肠肽在离体肠肌细胞中的功能

基本信息

批准号：
8755767
负责人：
S Murthy Karnam
金额：
$ 33.17万
依托单位：
VIRGINIA COMMONWEALTH UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1984
资助国家：
美国
起止时间：
1984-04-01 至 2018-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8755767
关键词：
Adverse effects Affect Animal Model Attenuated Blood Vessels Calcineurin Colon Constipation Cyclic AMP Cyclic AMP-Dependent Protein Kinases Cyclic GMP Cystathionine Development Diabetes Mellitus Diabetic mouse Down-Regulation Enteric Nervous System Enzymes Equilibrium Functional disorder Gastric Emptying Gastrointestinal Motility Gastrointestinal tract structure Glucose Goals Human Hybrids Hyperglycemia Impairment In Vitro Interstitial Cell of Cajal Intraperitoneal Injections Knowledge Link Lyase Mediating Metabolic MicroRNAs Molecular Mus Muscle Cells Muscle Contraction Muscle Tonus Muscle function Muscle relaxation phase Myosin Light Chains Nervous system structure Nutritional status Pathway interactions Patients Peptides Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Promoter Regions RNA Relaxation Rho-associated kinase Role Sequence Analysis Signal Pathway Signal Transduction Smooth Muscle Smooth Muscle Myocytes Stomach Testing Up-Regulation Visceral cell motility db/db mouse diabetic diabetic patient in vivo inhibitor/antagonist insight motility disorder mouse model nerve supply novel novel strategies phospholamban phosphoric diester hydrolase public health relevance sulfhydration transcription factor

项目摘要

DESCRIPTION (provided by applicant): Abnormalities in extrinsic and intrinsic innervation and in the abundance and distribution of interstitial cells of Cajal are known to contribute to impairment of gastrointestinal motility in diabetes. Abnormalities in smooth muscle function in relation to diabetes have not been fully explored. The proposed studies are intended to fill this gap in our knowledge. Our previous studies showed that sustained smooth muscle contraction and relaxation are regulated by the RhoA/Rho kinase and cGMP/PKG pathways, respectively. Our preliminary studies in diabetic animal models (NOD and db/db mice) and human diabetic smooth muscle have shown that hyperglycemia causes upregulation of the RhoA/Rho kinase pathway and downregulation of the cGMP/PKG pathway leading to sustained increase in smooth muscle contraction and decrease in its ability to relax. The focus of this proposal is to define the molecular mechanisms that trigger these changes in smooth muscle signaling and identify their contribution to motility dysfunction in diabetes. 1) Microarray and RNA hybrid analysis of control and diabetic gastric and colonic smooth muscle revealed a functional link between miR-133a and RhoA expression that led us to hypothesize that a decrease in miR-133a expression in diabetic smooth muscle mediates the increase in RhoA expression leading to upregulation of the RhoA/Rho kinase pathway and sustained increase in muscle contraction (Specific Aim 1). 2) Sequence analysis of the human and mouse PDE5 promoter region in gastric and colonic smooth muscle identified a link to transcription factor NFATc4 that led us to hypothesize that O- GlcNAcylated phospholamban mediates sequential activation of calcineurin and NFATc4 and increase in PDE5 expression leading to downregulation of the cGMP/PKG pathway and inhibition of muscle relaxation (Specific Aim 2). 3) Preliminary studies identified a link between miR-21 and a decrease in cystathionine- ¿-lyase (CSE) expression in diabetic smooth muscle that led us to hypothesize that a decrease in endogenous H2S formation attenuates inhibitory S-sulfhydration of RhoA and PDE5 and promotes upregulation of the RhoA/Rho kinase and downregulation of the cGMP/PKG pathways (Specific Aim 3). The novel concepts underlying these hypotheses have been validated by preliminary studies in smooth muscle of human and diabetic NOD and db/db mice and support the notion that specific alterations in smooth muscle signaling are driven by high glucose levels. A novel approach involving intraperitoneal injection of miR-133a, miR-21, and other specific inhibitors so as to block selectively each pathway provided evidence that these specific alterations in smooth muscle signaling contribute to motility dysfunction in diabetes. Completion of these studies will expand our understanding of overall motility dysfunction in diabetes and offer avenues for the development of novel therapies.

描述（由适用提供）：已知Cajal的外在和内在神经的异常以及Cajal间质细胞的丰度和分布有助于糖尿病中胃肠道运动的损害。尚未完全探索与糖尿病相关的平滑肌功能异常。拟议的研究旨在填补我们的知识。我们先前的研究表明，持续的平滑肌收缩和松弛受RhoA/Rho激酶和CGMP/PKG途径的调节。我们在糖尿病动物模型（NOD和DB/DB小鼠）和人糖尿病平滑肌方面的初步研究表明，高血糖会导致RhoA/Rho激酶途径的上调，以及CGMP/PKG途径的下调，导致平滑肌摄取和降低能力的持续增长。该建议的重点是定义触发平滑肌信号变化的分子机制，并确定它们对糖尿病运动功能障碍的贡献。 1）对照和糖尿病胃和结肠平滑肌的微阵列和RNA杂交分析揭示了miR-133a和RhoA表达之间的功能联系，这使我们假设糖尿病平滑肌中miR-133a表达的下降会导致RhoA表达的增加导致RhoA/Rho Kinase Path的上调，并促进了use速度的增加，并增加了1次忙碌的男接受忙碌的忙碌（增长）忙碌（增长了忙碌的男术忙碌（增长）。 2）胃和结肠平滑肌中人和小鼠PDE5启动子区域的序列分析确定了与转录因子NFATC4的联系2）。 3) Preliminary studies identified a link between miR-21 and a decrease in cystathionine- ¿ -lyase (CSE) expression in diabetic smooth muscle that led us to hypothesize that a decrease in endogenous H2S formation attenuates inhibitory S-sulfhydration of RhoA and PDE5 and promotes upregulation of the RhoA/Rho kinase and downregulation of the cGMP/PKG途径（特定目标3）。这些假设背后的新概念已通过人类和糖尿病点的平滑肌和DB/DB小鼠的初步研究来验证，并支持这样的观点，即平滑肌信号传导的特定变化是由高葡萄糖水平驱动的。一种涉及miR-133a，miR-21和其他特定抑制剂的新方法，涉及腹膜内注射，以便阻止每种途径，证明平滑肌信号传导中的这些特定变化有助于糖尿病的运动功能障碍。这些研究的完成将扩大我们对糖尿病总体运动功能障碍的理解，并为开发新疗法提供途径。