Researchers have identified a naturally occurring molecule that has the potential for preserving sites of communication between nerves and muscles in amyotrophic lateral sclerosis (ALS) and over the course of aging — as well as a molecule that interferes with this helpful process.
The discovery in mice has implications for patients with ALS, also known as Lou Gehrig's disease.
Published in The Journal of Neuroscience, the research team describes a growth factor called FGFBP1, which is secreted by muscle fibers and maintains neuromuscular junctions — a critical type of synapse that allows the spinal cord to communicate with muscles, sending signals from the central nervous system to create movements.
In mouse models of ALS, a growth factor associated with the immune system, called TGF-beta, emerges and prevents muscles from secreting factors needed to maintain their connections with neurons.
"TGF-beta is upregulated in ALS and in turn blocks expression of FGFBP1, which is released by muscle fibers to preserve the integrity of the neuromuscular junction," said Gregorio Valdez, who led the study. "The body is trying to help itself by generating more TGF-beta. Unfortunately, TGF-beta accumulates at the synapse where it blocks expression of FGFBP1, accelerating degeneration of the neuromuscular junction."
FGFBP1 also gradually decreases during aging, but more precipitously in ALS, because TGF-beta accumulates at the synapse, according to the researchers.
Paper: “Muscle fibers secrete FGFBP1 to slow degeneration of neuromuscular synapses during aging and progression of ALS”
Reprinted from materials provided by Virginia Tech.