在激素刺激的胰岛素分泌β细胞中周期性AMP的振荡
Oleg Dyachok1, Yegor Isakov, Jenny Sågetorp
1Department of Medical Cell Biology, Uppsala University, BMC, Box 571, SE-751 23 Uppsala, Sweden.
Nature
|January 20, 2006
概括
胰腺β细胞中的循环AMP (cAMP) 振荡,影响胰岛素分泌. 这些cAMP振荡与信号相互作用并调节基因转录,揭示了一个新的信号机制.
科学领域:
- 蜂信号传输是如何进行的
- 内分泌学 在内分泌学.
- 分子生物学分子生物学
背景情况:
- 循环AMP (cAMP) 是一个关键的第二信使,调节细胞功能,如胰岛素分泌.
- 在胰腺β细胞中,cAMP增强了由葡萄糖和GLP-1刺激的依赖的表细胞分裂和胰岛素释放.
- 贝塔细胞中受体触发的cAMP信号的时间动态在很大程度上仍未被描述.
研究的目的:
- 为了研究胰腺β细胞中cAMP的动力学和信号模式.
- 探索cAMP和信号在胰岛素分泌中的相互作用.
- 阐明cAMP信号动态对细胞目标的下游影响.
主要方法:
- 开发和应用一种新型的比度渐变波微镜技术.
- 同时测量β细胞中的细胞内cAMP和Ca2+度.
- 对激素刺激 (葡萄糖,GLP-1) 的反应中cAMP信号动态的分析.
主要成果:
- 胰岛素分泌的β细胞在用葡萄糖和GLP-1刺激时表现出cAMP度的明显波动.
- cAMP和Ca2+信号通路是相互连接和相互增强的.
- 持续的cAMP升高,而不是振荡,触发了cAMP依赖的蛋白激酶催化子单元的核转移.
结论:
- 贝塔细胞中受体触发的cAMP信号的特征是振荡,代表了一种新的信号模式.
- 对于调节不同的下游细胞反应而言,cAMP信号的时间动态至关重要.
- 了解cAMP振荡动力学,可以了解胰岛素分泌和基因转录的差异调节.
相关概念视频
Intracellular Signaling Cascades
44.8K
Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner is called signal transduction. Signal transduction only occurs with cell-surface receptors, which cannot interact with most components of the cell, such as DNA. Only internal receptors can interact directly with DNA in the nucleus to initiate protein synthesis. When a ligand binds to its receptor, conformational changes occur that affect the...
44.8K
Insulin Secretory Vesicles
6.3K
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
6.3K
cAMP-dependent Protein Kinase Pathways
7.3K
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
7.3K
Feedback Regulation of Calcium Concentration
2.9K
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
2.9K
Hormones Regulating Blood Glucose
7.5K
Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
In addition to accelerating glucose uptake and utilization, insulin has...
7.5K
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
2.8K
The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are...
Insulin and C-peptide are...
2.8K


