Adipsin is an adipokine that improves β cell function in diabetes

Area of Science:

• Metabolic disease research
• Endocrinology
• Molecular biology

Background:

• Type 2 diabetes mellitus (T2DM) is characterized by pancreatic beta cell failure, leading to insulin deficiency and high blood sugar.
• The role of adipokines, signaling molecules from fat tissue, in regulating beta cell function is an area of active investigation.

Purpose of the Study:

• To investigate the role of the adipokine adipsin in maintaining pancreatic beta cell function and its potential as a therapeutic target for T2DM.

Main Methods:

• Utilized genetically modified animal models lacking adipsin to assess glucose metabolism and insulin secretion.
• Isolated pancreatic islets were used to study glucose-stimulated insulin secretion.
• Administered adipsin to diabetic mice to evaluate its effects on hyperglycemia.
• Identified and characterized the downstream signaling pathway of adipsin, including the peptide C3a and its receptor.

Main Results:

• Mice lacking adipsin exhibited glucose intolerance and reduced insulin secretion.
• Adipsin replenishment in diabetic mice improved hyperglycemia by enhancing insulin secretion.
• The peptide C3a, generated by adipsin, was identified as a potent insulin secretagogue.
• The C3a receptor was found to be essential for adipsin's beneficial effects on islets, mediated by increased ATP, respiration, and Ca(2+) levels.
• Type 2 diabetes patients with beta cell failure showed reduced adipsin levels.

Conclusions:

• The adipsin/C3a signaling pathway represents a critical link between adipose tissue and pancreatic beta cell function.
• This pathway plays a beneficial role in maintaining beta cell physiology.
• Targeting the adipsin/C3a pathway offers a promising therapeutic strategy for managing type 2 diabetes mellitus.