#glycogen

The Scientific Research Notes of S. Sunkavally. Years: 1986 - 1990.

Propaganda!

Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. It is the main storage form of glucose in the human body. In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle.

Molecular embroidery!

The Epinephrine pathway, Insulin Pathway, and Glucose regulation bag In more detail - showing all the different molecules involved and the different pathways and signalling cascades.

Model Muscle

Infantile-onset Pompe disease (IOPD) is a rare but life-threatening disease. It causes skeletal and heart muscle weakness due to a deficiency in an enzyme called acid alpha-glucosidase (GAA). Current treatment with healthy GAA doesn’t provide a complete cure. Researchers now investigate why using the first-ever 3D human skeletal muscle model in a dish. Bundles of human muscle fibres, myobundles (pictured), were grown from muscle cells collected from healthy (left) and IOPD patients (right). IOPD myobundles replicated patient symptoms — reduced GAA enzyme activity, elevated glycogen levels and poor muscle function when under metabolic stress. Treating these myobundles with human GAA, increased GAA activity and reduced glycogen levels as shown by measuring specific protein levels. But this didn’t improve muscle function under stress, as demonstrated by measuring forces generated when myobundles contracted. This model, therefore, presents an effective way to gain new insights into IOPD and potential treatments.

Written by Lux Fatimathas

Image adapted from work by Jason Wang and colleagues

Department of Biomedical Engineering, Duke University, Durham, NC, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Communications Biology, May 2021