Transforming growth factor beta (TGF-β1) released by astrocytes has been implicated in mediating motor neuron death in ALS (see Apr 2015 news). Now, it is resurfacing as an agent of destruction through another avenue: it contributes to neuromuscular junction (NMJ) abnormalities in ALS. According to a paper in the November 14 Journal of Neuroscience, muscle fibers secrete fibroblast growth factor binding protein 1 (FGFBP1) and concentrate it at the NMJs, but in aging and in SOD1-ALS models, its expression declines. What causes the change in FGFBP1 expression? The researchers honed in on TGF-β1, which accumulates at the neuromuscular synapse during aging and in SOD1-ALS mice and inhibits FGFBP1 expression. These studies point to a potential therapeutically-relevant pathway to protect NMJ integrity in ALS.
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Taetzsch T, Tenga MJ, Valdez G. Muscle fibers secrete FGFBP1 to slow degeneration of neuromuscular synapses during aging and progression of ALS. J. Neurosci. 14 November 2016, 2992-16.