Related Experiment Video
Updated: Jun 16, 2026
12:33
A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination
Published on: June 25, 2014
Pancreatic islet α cell function and proliferation require the arginine transporter SLC7A2
Erick Spears1,2, Jade E Stanley1,3, Matthew Shou1
1Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
The Journal of Clinical Investigation
|June 15, 2026
Summary
The cationic amino acid transporter SLC7A2 is crucial for alpha cell proliferation and function. It responds to amino acids, impacting glucose regulation and potentially HbA1c levels.
Area of Science:
- Endocrinology
- Metabolism
- Cell Biology
Background:
- Glucagon signaling interruption lowers blood glucose but causes hyperaminoacidemia.
- This hyperaminoacidemia stimulates alpha cell proliferation and glucagon secretion.
- Alpha cells likely sense amino acid levels through specific transporters.
Purpose of the Study:
- To investigate the role of amino acid transporters in alpha cell response to interrupted glucagon signaling.
- To identify the specific transporters involved in alpha cell proliferation and function.
Main Methods:
- Comparative analysis of amino acid transporter expression in alpha vs. beta cells (mouse and human).
- Utilized cell culture, zebrafish, and Slc7a2 knockout mouse models.
- Assessed islet function ex vivo and in vivo in Slc7a2-/- mice.
- Investigated arginine activation of mTOR signaling and SLC38A5 induction.
Main Results:
- SLC7A2 is the most highly expressed cationic amino acid transporter in alpha cells.
- Arginine and SLC7A2 are essential for alpha cell proliferation following interrupted glucagon signaling.
- Slc7a2 deficiency impaired arginine-stimulated glucagon and insulin secretion.
- SLC7A2 mediates arginine-induced mTOR signaling and SLC38A5 expression.
- Single nucleotide polymorphisms in SLC7A2 are associated with HbA1c levels.
Conclusions:
- SLC7A2 plays a central role in amino acid-stimulated alpha cell proliferation.
- SLC7A2 is critical for regulating islet hormone secretion and glucose homeostasis.
- SLC7A2 is a key mediator in the liver/alpha cell axis response to altered nutrient levels.
Related Concept Videos
01:27Glucose 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...
01:05Insulin 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...
01:27Glucose Transporters
Glucose transporters facilitate the transport of glucose across the cell membrane. In addition to glucose, some glucose transporters can also aid the movement of other hexoses such as fructose, mannose, and galactose.
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
01:26Glucose Absorption Into the Small Intestine
Complex carbohydrates consumed cannot be absorbed into the small intestine in their original form. First, they must be hydrolyzed to a monosaccharide form such as glucose or galactose. These monosaccharides are then transported across the intestinal membrane and into the blood via transcellular transport. The intestinal epithelial cells allow the movement of these monosaccharides with a defined 'entry' through membrane transporter proteins present on their apical membrane and 'exit' via the...
01:28Insulin: 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...
01:16Cells 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...