Influence of melatonin receptor signalling on parameters involved in blood glucose regulation

Area of Science:

• Endocrinology
• Metabolic Regulation
• Molecular Biology

Background:

• The pineal hormone melatonin influences insulin secretion through MT1 and MT2 G-protein-coupled receptors.
• Understanding melatonin's role in glucose homeostasis is crucial for metabolic health.

Purpose of the Study:

• To elucidate the impact of melatonin receptor signaling on blood glucose regulation.
• To investigate the effects of MT1 and MT2 receptor deletion on metabolic parameters and gene expression.

Main Methods:

• Utilized mouse lines with deletions in MT1, MT2, or both melatonin receptors.
• Compared metabolic parameters (blood glucose, body weight, plasma insulin, and melatonin) between knockout and wild-type mice.
• Analyzed transcript levels of pancreatic islet hormones and glucose transporters (Glut1, Glut2) using reverse transcription polymerase chain reaction.

Main Results:

• MT1- and double-knockout mice exhibited increased plasma insulin and melatonin, with decreased blood glucose and body weight compared to wild-type.
• Melatonin receptor deletion altered glucose concentrations, body weight, and hormone levels in an age- and receptor-dependent manner.
• Receptor deficiency impacted transcript levels of pancreatic hormones and glucose transporters, with Glut1 transcript decreasing in INS-1 cells under melatonin stimulation.

Conclusions:

• Melatonin receptor knockout mouse models demonstrate distinct effects on blood glucose levels, body weight, and plasma hormone concentrations.
• Melatonin receptor signaling is essential for regulating glucose metabolism, insulin levels, and the expression of key metabolic genes.