Dr. Rashmi Kothary and his team have recently published a paper, “Differential induction of muscle atrophy pathways in two mouse models of spinal muscular atrophy” in the journal Scientific Reports. This research was funded in part by grant from Cure SMA.
Individuals with SMA do not produce survival motor neuron (SMN) protein at high enough levels, leading to debilitating and often fatal muscle weakness. One of the key unanswered research questions is where and when SMN needs to be delivered in order to provide benefit to those with SMA. Recent research has found that increasing SMN in the central nervous system may not completely alleviate the symptoms of SMA in certain mouse models of SMA, suggesting there are also defects in other tissues, such as the skeletal muscles, that may need to be addressed.
Dr. Kothary and his team found that muscle degradation pathways are activated in both an intermediate and severe SMA model mice, and that the muscle weakness occurred prior to any overt motor neuron pathology. The patterns of atrophy were distinct between the intermediate and severe mouse models, suggesting that different types and severities of SMA might require different treatment strategies.
They also found that administration of a research tool compound called trichostatin A—not suitable for human use—showed promise in reversing some important molecular changes associated with atrophy, which could lead to further development of a treatment to address these muscle defects. Ultimately, treatments that address the muscles could be used in combination with treatments that address the loss of SMN.
This paper from Dr. Kothary further highlights the importance of combination therapies and multiple treatment approaches for all types, ages, and stages of SMA. It also provides insight into how mouse models could be used to develop more precise ways to measure change and evaluate the effects of a treatment for different SMA types.
The grant to Dr. Kothary was funded by Families of SMA Canada.