@article{DengReinhardHennleinetal.2022,
  author    = {Deng, Chunchu and Reinhard, Sebastian and Hennlein, Luisa and Eilts, Janna and Sachs, Stefan and Doose, S{\"o}ren and Jablonka, Sibylle and Sauer, Markus and Moradi, Mehri and Sendtner, Michael},
  title     = {Impaired dynamic interaction of axonal endoplasmic reticulum and ribosomes contributes to defective stimulus-response in spinal muscular atrophy},
  series = {Translational Neurodegeneration},
  volume    = {11},
  journal   = {Translational Neurodegeneration},
  number    = {1},
  issn      = {2047-9158},
  doi       = {10.1186/s40035-022-00304-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300649},
  year      = {2022},
  abstract  = {Background: Axonal degeneration and defects in neuromuscular neurotransmission represent a pathological hallmark in spinal muscular atrophy (SMA) and other forms of motoneuron disease. These pathological changes do not only base on altered axonal and presynaptic architecture, but also on alterations in dynamic movements of organelles and subcellular structures that are not necessarily reflected by static histopathological changes. The dynamic interplay between the axonal endoplasmic reticulum (ER) and ribosomes is essential for stimulus-induced local translation in motor axons and presynaptic terminals. However, it remains enigmatic whether the ER and ribosome crosstalk is impaired in the presynaptic compartment of motoneurons with Smn (survival of motor neuron) deficiency that could contribute to axonopathy and presynaptic dysfunction in SMA. Methods: Using super-resolution microscopy, proximity ligation assay (PLA) and live imaging of cultured motoneurons from a mouse model of SMA, we investigated the dynamics of the axonal ER and ribosome distribution and activation. Results: We observed that the dynamic remodeling of ER was impaired in axon terminals of Smn-deficient motoneurons. In addition, in axon terminals of Smn-deficient motoneurons, ribosomes failed to respond to the brain-derived neurotrophic factor stimulation, and did not undergo rapid association with the axonal ER in response to extracellular stimuli. Conclusions: These findings implicate impaired dynamic interplay between the ribosomes and ER in axon terminals of motoneurons as a contributor to the pathophysiology of SMA and possibly also other motoneuron diseases.},
  language  = {en}
}
@article{FrancoEspinGatiusArmengoletal.2022,
  author    = {Franco-Espin, Julio and Gatius, Ala{\´o} and Armengol, Jos{\´e} {\´A}ngel and Arumugam, Saravanan and Moradi, Mehri and Sendtner, Michael and Calder{\´o}, Jordi and Tabares, Lucia},
  title     = {SMN is physiologically downregulated at wild-type motor nerve terminals but aggregates together with neurofilaments in SMA mouse models},
  series = {Biomolecules},
  volume    = {12},
  journal   = {Biomolecules},
  number    = {10},
  issn      = {2218-273X},
  doi       = {10.3390/biom12101524},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290263},
  year      = {2022},
  abstract  = {Survival motor neuron (SMN) is an essential and ubiquitously expressed protein that participates in several aspects of RNA metabolism. SMN deficiency causes a devastating motor neuron disease called spinal muscular atrophy (SMA). SMN forms the core of a protein complex localized at the cytoplasm and nuclear gems and that catalyzes spliceosomal snRNP particle synthesis. In cultured motor neurons, SMN is also present in dendrites and axons, and forms part of the ribonucleoprotein transport granules implicated in mRNA trafficking and local translation. Nevertheless, the distribution, regulation, and role of SMN at the axons and presynaptic motor terminals in vivo are still unclear. By using conventional confocal microscopy and STED super-resolution nanoscopy, we found that SMN appears in the form of granules distributed along motor axons at nerve terminals. Our fluorescence in situ hybridization and electron microscopy studies also confirmed the presence of β-actin mRNA, ribosomes, and polysomes in the presynaptic motor terminal, key elements of the protein synthesis machinery involved in local translation in this compartment. SMN granules co-localize with the microtubule-associated protein 1B (MAP1B) and neurofilaments, suggesting that the cytoskeleton participates in transporting and positioning the granules. We also found that, while SMN granules are physiologically downregulated at the presynaptic element during the period of postnatal maturation in wild-type (non-transgenic) mice, they accumulate in areas of neurofilament aggregation in SMA mice, suggesting that the high expression of SMN at the NMJ, together with the cytoskeletal defects, contribute to impairing the bi-directional traffic of proteins and organelles between the axon and the presynaptic terminal.},
  language  = {en}
}