叶黄素对胰岛素活性进行调节
B Cohen1, D Novick, M Rubinstein
1Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel. lvrub@weizmann.weizmann.ac.il
概括
调节食欲的荷尔蒙 - - 素,可能会影响肝脏中的胰岛素信号传递. 这项研究发现,素可以改变人类肝细胞中胰岛素诱导的活动,这表明它在肥胖中起着作用.
科学领域:
- 内分泌学 在内分泌学.
- 代谢过程中的代谢.
- 分子生物学分子生物学
背景情况:
- 莱普主要以通过其下丘脑受体 (OB-R) 调节食物摄入量而闻名.
- 在其他组织中存在OB-R变异,但它们的功能在很大程度上仍未被描述.
- 肥胖与改变的瘦素水平和胰岛素抵抗有关.
研究的目的:
- 为了研究一个OB-R变体在人类肝 (肝) 细胞中的功能.
- 为了确定白是否会影响肝脏中的胰岛素信号通路.
- 探索肝脏勒丁信号在与肥胖相关的代谢功能障碍中的潜在作用.
主要方法:
- 培养的人类肝细胞暴露于瘦素,其度与肥胖个体相关.
- 测量了胰岛素诱导的信号事件,包括胰岛素受体基质-1 (IRS-1) 铁酸化及其与生长因子受体结合蛋白2 (Grb2) 的关联.
- 评估了与IRS-1相关的酸氨基3-激酶 (PI3K) 的活性和葡萄糖生成的调节.
主要成果:
- 丁暴露减弱了肝细胞中的几种胰岛素诱导的活动.
- 具体来说,素降低了IRS-1的氨酸酸化和Grb2与IRS-1的关联.
- 莱普也导致了葡萄糖生成的下调,但增加了与IRS-1相关的PI3K的活性.
结论:
- 在人类肝细胞中存在一个功能性的OB-R变体.
- 素可以调节肝脏的关键胰岛素信号通路,包括那些参与葡萄糖代谢的通路.
- 这些发现表明,瘦素可能在通过肝脏机制改变肥胖个体的胰岛素敏感性方面发挥作用.
相关概念视频
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...
Regulation of Food Intake
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
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...
Insulin: The Receptor and Signaling Pathways
Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
Insulin: Dosing Regimen and Adverse Effects
Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance.
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...
Glucagon-like Receptor Agonists
Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...


