Everything in moderation: excessive nerve cell pruning leads to disease

One of the hallmarks of neurodegenerative diseases like #Alzheimer’s,#Parkinson’s, and #ALS is the deterioration and death of neurons. Traditionally, researchers have focused on the death of the neuron cell body, but a new study in Cell Reports shows that excessive axon pruning may trigger neuron death. Axon pruning happens throughout development and into adolescence, but then generally turns off once we hit adulthood. Researchers at McGill University and Montreal Neurological Institute and Hospital have shown that axon pruning restarts in #neurodegenerative disease, which leads to neuron death. The researchers focused on axons in dorsal root ganglion neurons. They found that certain caspases that direct axon pruning are suppressed by a protein known as XIAP (X-linked inhibitor of apoptosis). In healthy individuals, the cells are able to balance #caspase and XIAP activity. In neurodegenerative disease, however, this balance is altered, leading to a resumption of axon pruning and cell death. Neurodegeneration can only proceed, the scientists say, if XIAP activity decreases, which could point to a new therapeutic target for these diseases.

Read more: http://bit.ly/17SfjPU
Journal article: XIAP Regulates Caspase Activity in Degenerating Axons. Cell Reports, 2013