通过ATF6α和通过E2F1通过葡萄糖对β细胞增殖的双输入调节
Huguet V Landa-Galvan1, Thalia A Castro1, Jahi J Noel1
1Division of Endocrinology, Diabetes and Metabolism and the Joan and Sanford I. Weill Center for Metabolic Health, Weill Cornell Medicine, New York, NY.
Diabetes
|October 31, 2025
概括
激活转录因子6 (ATF6α) 通过E2F1促进胰腺β细胞的增殖,但需要葡萄糖. 循环素依赖性激酶4/6 (CDK4/6) 通过酸化视网膜母细胞瘤蛋白来实现这一过程,该蛋白作为葡萄糖传感器.
科学领域:
- 细胞生物学 细胞生物学
- 内分泌学 在内分泌学.
- 糖尿病研究 糖尿病研究
背景情况:
- 增加胰腺β细胞质量对于糖尿病管理至关重要.
- 在高胰岛素需求期间,包括激活转录因子6 (ATF6α) 在内的内质网膜 (ER) 应激反应通路被激活.
- ATF6α促进β细胞增殖,但其机制和葡萄糖依赖性尚不清楚.
研究的目的:
- 阐明ATF6α诱导β细胞增殖的机制.
- 了解ATF6α媒介增殖的依赖葡萄糖的调节.
- 确定增强β细胞质量的潜在治疗点.
主要方法:
- 在小鼠和人类小岛细胞中研究了ATF6α激活.
- 分析了E2F1,视网膜母细胞瘤 (Rb) 蛋白和循环素依赖激酶 (CDK4/6) 在β细胞增殖中的作用.
- 利用thapsigargin诱导普遍的ER压力并评估E2F1表达和活性.
主要成果:
- ATF6α的激活增加了E2F1的表达,一个关键的细胞循环驱动器,以葡萄糖依赖的方式.
- 在正常葡萄糖中,E2F1活性受到Rb脱酸化的抑制,但在高葡萄糖中通过CDK4/6对Rb酸化后被激活.
- 过度表达CDK4或CDK6在正常葡萄糖和人类β细胞中分别挽救了ATF6α诱导的β细胞增殖.
结论:
- 一种新的双输入机制调节β细胞的增殖,整合ER压力 (通过ATF6α) 和血糖状况 (通过CDK4/6-介导的Rb酸化).
- Rb酸化作为葡萄糖传感器,允许ATF6α驱动的增殖.
- 准ATF6α-CDK4/6-Rb-E2F1轴为糖尿病患者增加β细胞质量提供了一个潜在的策略.
相关概念视频
Cell Specific Gene Expression
16.2K
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...
16.2K
Hormones Regulating Blood Glucose
6.4K
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...
6.4K
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
2.1K
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...
2.1K
Insulin Secretory Vesicles
6.4K
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...
6.4K
cAMP-dependent Protein Kinase Pathways
8.3K
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,...
8.3K
Glucose Homeostasis: Regulation of Blood Glucose
3.8K
Carbohydrates consumed through foods are converted into glucose, a crucial energy source for the body. In the prandial state, high blood glucose levels stimulate the secretion of insulin from the pancreas. Insulin inhibits hepatic glucose production and stimulates glucose uptake and metabolism by muscle and adipose tissue. The excess glucose is converted into glycogen and stored in the liver and muscles.
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
3.8K


