Cure SMA-funded researcher Chien-Ping Ko has published a paper in the Journal of Neuroscience, called “Defects in Motoneuron–Astrocyte Interactions in Spinal Muscular Atrophy.” The research for this paper was supported by a donation from the Dhont Family Foundation to Cure SMA.
Individuals with SMA don’t correctly produce survival motor neuron (SMN) protein at high enough levels, due to a mutation in the SMN1 gene. Researchers have found that mouse models of SMA improve when SMN protein is restored in astrocytes, which are cells that give support to motor neurons.
This suggests that astrocytes also play a role in SMA, along with motor neurons. It also suggests that we may be able to identify new therapeutic targets by addressing this underlying mechanism.
Using mixed and matched cell cultures of pure motoneurons and astrocytes from both SMA mice and healthy mice, researchers we able to measure how both cell types contribute to motor neuron and muscle synapse loss in SMA. “Synapse” refers to the electrical transmissions between motor neurons, or other types of neurons, and/or muscle cells. These transmissions are essential to proper motor function.
In pure motoneuron cultures, SMA motoneurons exhibited normal survival but intrinsic defects in synapse formation and synaptic transmission. In pure astrocyte cultures, SMA astrocytes exhibited defects in an important cellular function called calcium homeostasis. In cultures with both motoneurons and astrocytes, synapse formation and synaptic transmission were significantly reduced when either motoneurons, astrocytes, or both, were from SMA mice compared with those in non-SMA mice.
This research will be used as the basis for further experimentation on how astrocytes are involved in SMA, and how they might be used to treat SMA. Congratulations to Dr. Ko and his team on their accomplishments.