While spinal muscular atrophy (SMA), generally, has still no cure, experts at Brown University have found a “multipronged counterattack” for older patients and their families. In December last year, the first treatment for the disease acquired US market approval. Alarmingly, the disease remains to be fatal in early childhood.
Now, per Science Daily, a new study led by Brown University widens the current understanding of researchers on how genetic mutation undermines the communication between motor neurons and the muscles they control. The same mutation cause spinal muscular atrophy cases.
In the report, about one in every 8,000 children is born with some kind of SMA. The mutation in both copies of the gene that code for the survival motor neuron (SMN) protein interrupts its production. Therefore, a dysfunction of motor neurons that control muscles occurs. The most severe form, Type l, causes children to die by the age of two years. Unfortunately, even the fundamental breathing control gets compromised.
Although other SMA patients live much longer than the others, they still suffer significant muscle weakness. Anne Heart, a senior author of the study and a professor of neuroscience at Brown University, says if they can have a deeper understanding about SMH, they can create combinatorial therapies. One will raise SMN levels and the other will help neurons survive in the challenge of too little SMN.
In 206, Heart’s lab published proofs that one mechanistic consequence of the disease is a disruption of the process by which neurons can recycle proteins needed for neural control of muscles. For his part, graduate student Patrick O’Hern reveals a new complex cause-and-effect sequence in both C. Elegans worm and mice models of SMA. Per UPI, the researchers at Brown – in collaboration with the University of Cologne, Germany – concluded that lack of SMN disrupts the working of the protein Gemini 3, which lessens the activity of a particular microRNA needed to stop the overexpression of a motor neuron receptor called m2R.
If there are too many m2R receptors caused by overexpression in SMA, motor neurons will be too sensitive to their acetylcholine output. The latter causes motor neurons to prematurely shut down its release, affecting muscle function later on. Heart added that if they will be able to decrease the activity of these receptors, the results “could be beneficial.”