エフスとエフリンは,臓のベータ細胞を結びつけています
Rohit N Kulkarni1, C Ronald Kahn
1Division of Cell and Molecular Physiology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston MA 02215, USA. rohit.kulkarni@joslin.harvard.edu
Cell
|April 24, 2007
まとめ
臓のβ細胞は,インスリン分泌を調節するシグナルタンパク質EphAとエフリン-Aを介して通信します. この発見は,なぜベータ細胞が臓の小島に集まるのかについての新しい洞察を提供します.
科学分野:
- 細胞生物学 細胞生物学
- エンドクリノロジー エンドクリノロジー
- 分子シグナル伝達です.
背景:
- インスリン分泌に不可欠な臓ベータ細胞の細胞間通信機構は,まだ十分に理解されていません.
- 臓の小島にベータ細胞が集まる現象は知られているが,その機能的意義は不明である.
研究 の 目的:
- 臓のベータ細胞間のコミュニケーションを媒介するシグナル伝達タンパク質の役割を調査する.
- 臓の小島におけるβ細胞のクラスタリングの機能的意義を探求する.
主な方法:
- コンスタンティノヴァ等による研究. (2007) では,分子信号伝達経路解析を用いた.
- ベータ細胞のコミュニケーションにおけるEphAとエフリン-Aタンパク質の機能を調査した.
主要な成果:
- シグナル伝達タンパク質のEphAとエフリンAが,インスリン分泌を調節する役割を果たしていることが判明しました.
- これらのタンパク質は,小島内のベータ細胞のクラスタリングに関する機能的な洞察を提供します.
結論:
- エファとエフリンAシグナル伝達は,臓のβ細胞通信の重要な調節因子である.
- ベータ細胞のクラスタリングは機能的に重要であり,これらのシグナル伝達経路によって媒介され,インスリン分泌に影響を与える可能性が高い.
関連する概念動画
Cell Specific Gene Expression
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
Insulin Secretory Vesicles
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...
Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
Erythropoietin-producing hepatocellular carcinoma receptor (Eph) and its ligand, Eph receptor-interacting protein (Ephrin) were first discovered in the human carcinoma cell line, hence the name. Ephrin-Eph interaction guides cells to reach their appropriate location in adult tissues. They also play an essential role in the immune system by helping in immune cell migration, adhesion, and activation. Based on their structure and function, Eph is divided into two classes — EphA and EphB.
Cells and Secretions of the Pancreas
The pancreas, a vital organ within the abdominal cavity, plays dual roles in the digestive and endocrine systems, collaborating with exocrine and endocrine cells to maintain optimal digestion and blood sugar levels.
Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices.
Concurrently, the dispersed clusters of endocrine cells throughout the...
Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices.
Concurrently, the dispersed clusters of endocrine cells throughout the...
Hormones Regulating Blood Glucose
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...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
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 co-secreted in...
Insulin and C-peptide are co-secreted in...


