The Chair of our Scientific Advisory Board, Professor Brunhilde Wirth of the University of Cologne, published an important paper in the American Journal of Human Genetics.
This study, partly funded by SMA Europe, unravels impaired endocytosis in SMA. Endocytosis is a mechanism used by cells to recycle and transport molecules by engulfing them. This is especially important in neurons, because they have to rapidly release neurotransmitters to communicate with each other and with muscles. Without this specialised neurotransmitter recycling, synaptic vesicles are not recycled fast enough to keep up with nerve and muscle cell activity.
Wirth et al. go on to show that increasing the levels of two genetic modifiers, Plastin 3 and Coronin1C, coupled with administration of low dose SMN antisense oligonucleotide, improves disease state in SMA animal models dramatically. The team therefore hypothesised that disturbed endocytosis might be a key cellular mechanism underlying impaired neurotransmission and neuromuscular junction maintenance in SMA.
The team’s work identifies a new and potentially exciting point of intervention in the treatment of SMA. Altering levels of molecules involved in endocytosis might be used in conjunction with SMN-enhancing agents in a combination therapy of the future.
S. Hosseinibarkooie et al. The Power of Human Protective Modifiers: PLS3 and CORO1C Unravel Impaired Endocytosis in Spinal Muscular Atrophy and Rescue SMA Phenotype. Am J Hum Genet. 2016 Sep 1;99(3):647-65. doi: 10.1016/j.ajhg.2016.07.014. Download the paper here, through the AJHG website.