Lipid-associated metabolic signalling networks in pancreatic beta cell function

Area of Science:

• Metabolic regulation of insulin secretion
• Pancreatic beta cell function
• Endocrinology

Background:

• Glucose-stimulated insulin secretion (GSIS) involves ATP-sensitive potassium (KATP)-dependent and independent pathways.
• Lipid signaling and anaplerosis are key amplification pathways in GSIS.
• A metabolic partitioning switch involving acetyl-CoA carboxylase (ACC)/malonyl-CoA/carnitine palmitoyltransferase-1 (CPT-1) has been proposed.

Purpose of the Study:

• To review evidence for the ACC/malonyl-CoA/CPT-1 axis in controlling GSIS.
• To highlight the axis's importance in conditions with elevated fatty acids.
• To link this axis to the broader glycerolipid/non-esterified fatty acid (NEFA) cycle.

Main Methods:

• Review of existing scientific literature and studies.
• Analysis of metabolic signaling pathways in pancreatic beta cells.
• Integration of data on lipid metabolism and insulin secretion.

Main Results:

• The ACC/malonyl-CoA/CPT-1 axis plays a critical role in beta cell response to glucose and fatty acids.
• This axis is particularly important under conditions of hyperlipidaemia, fasting, and diabetes.
• The axis is interconnected with the glycerolipid/NEFA cycle, influencing lipolysis and lipid signaling.

Conclusions:

• The ACC/malonyl-CoA/CPT-1 axis is a central regulator of fuel-stimulated insulin secretion.
• Understanding this axis provides insights into metabolic dysregulation in diabetes and hyperlipidaemia.
• Acetyl-CoA carboxylase may also influence pancreatic beta cell growth.