Functional peroxisomes are required for β-cell integrity in mice.

Area of Science:

• Cell Biology
• Metabolic Research
• Endocrinology

Background:

• Peroxisomes are vital organelles involved in lipid and reactive oxygen species metabolism.
• The specific role of peroxisomes in pancreatic beta-cell function remains largely unexplored.

Purpose of the Study:

• To investigate the contribution of peroxisomal metabolism to pancreatic beta-cell homeostasis.
• To determine the impact of impaired peroxisome function on glucose metabolism and insulin secretion.

Main Methods:

• Generated inducible, beta-cell-specific PEX5 knockout mice (Rip-Pex5-/-).
• Administered tamoxifen and high-fat diet (HFD) to induce PEX5 deletion and metabolic stress.
• Performed phenotypic analysis, including glucose tolerance tests, insulin secretion assays, and biochemical/ultrastructural analyses.

Main Results:

• Impaired peroxisomal metabolism was confirmed by altered fatty acid and plasmalogen levels.
• Rip-Pex5-/- mice exhibited glucose intolerance and reduced insulin secretion.
• Beta-cells showed mitochondrial dysfunction, decreased insulin granules, vacuole overload, increased apoptosis, and reduced beta-cell mass.

Conclusions:

• Normal peroxisome metabolism is essential for maintaining pancreatic beta-cell structure and function.
• Disruption of peroxisome function significantly compromises beta-cell health and glucose homeostasis.