Transfer of ARNs and ribosomas from glias to axons

Abstract

Whether axons contain RNAs and ribosomes has been motive of discussion along decades. Nowadays, it is accepted that the neuronal soma provides axons with both mRNAs (messenger RNAs) and ribosomes, by axoplasmic transport. Nevertheless, without denying neuron soma origin, an alternative origin has been proposed: the adaxonal glia. This review describes new evidence supporting glia-to-axon ribosomes and RNAs transfer and describes these processes in invertebrate as well as in vertebrate axons. The important implications of the transfer of messenger RNAs, micro RNAs and ribosomes from glia to axon are discussed, especially in relation to the functional integration between glias and axons. Although more experimental support is needed to fundament this concept, which is recently evolving continuously, it strongly impacts on our understanding of the molecular and cellular biology of axons regarding function and pathology. It is possible that the physiopathology of many human axonal diseases should be deeply reviewed under the light of glia to axon RNA and ribosome transfer demonstration, as well as the regulatory role of glia over axonal protein synthesis. A better understanding of the above mentioned elements might help to pave the way for the introduction of controlled therapeutic measures during progressive neurodegeneration or axonal injury.