Glycogen shunt is essential for submandibular gland morphogenesis.

Area of Science:

• Developmental Biology
• Cellular Metabolism
• Organogenesis

Background:

• Glycogen metabolism is vital for cellular energy. The "glycogen shunt" concept regulates glycogen synthesis, accumulation, and breakdown for timely glucose provision, especially during organogenesis.
• Understanding glycogen's role in gland development is crucial for insights into developmental processes.

Purpose of the Study:

• To investigate the temporal and spatial localization of glycogen and related molecules during mouse submandibular gland development.
• To determine the functional role of glycogenolysis in submandibular gland morphogenesis and differentiation using organ culture.

Main Methods:

• Analysis of glycogen and related molecule localization in embryonic and postnatal mouse submandibular glands.
• In vitro organ culture of submandibular gland tissues with glycogenolysis inhibition using a glycogen phosphorylase inhibitor.

Main Results:

• Glycogen synthesis initiated at embryonic day 13.5 (E13.5), with accumulation and degradation observed at E15.5.
• Postnatally, glycogen-retained cells increased, with active synthesis and degradation in acinar and terminal tubule cells.
• Inhibition of glycogenolysis impaired early branching morphogenesis and significantly reduced acinar and myoepithelial cell differentiation.

Conclusions:

• The glycogen shunt is essential for early growth and cell differentiation during submandibular gland development.
• Glycogen metabolism dynamically regulates energy supply to support critical developmental events like branching and differentiation.