@article{TejeroAlsakkalHennleinetal.2023,
  author    = {Tejero, Rocio and Alsakkal, Mohammad and Hennlein, Luisa and Lopez-Cabello, Ana M. and Jablonka, Sibylle and Tabares, Lucia},
  title     = {Nifedipine ameliorates cellular differentiation defects of Smn-deficient motor neurons and enhances neuromuscular transmission in SMA mice},
  series = {International Journal of Molecular Sciences},
  volume    = {24},
  journal   = {International Journal of Molecular Sciences},
  number    = {8},
  issn      = {1422-0067},
  doi       = {10.3390/ijms24087648},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313636},
  year      = {2023},
  abstract  = {In spinal muscular atrophy (SMA), mutations in or loss of the Survival Motor Neuron 1 (SMN1) gene reduce full-length SMN protein levels, which leads to the degeneration of a percentage of motor neurons. In mouse models of SMA, the development and maintenance of spinal motor neurons and the neuromuscular junction (NMJ) function are altered. Since nifedipine is known to be neuroprotective and increases neurotransmission in nerve terminals, we investigated its effects on cultured spinal cord motor neurons and motor nerve terminals of control and SMA mice. We found that application of nifedipine increased the frequency of spontaneous Ca\(^{2+}\) transients, growth cone size, cluster-like formations of Cav2.2 channels, and it normalized axon extension in SMA neurons in culture. At the NMJ, nifedipine significantly increased evoked and spontaneous release at low-frequency stimulation in both genotypes. High-strength stimulation revealed that nifedipine increased the size of the readily releasable pool (RRP) of vesicles in control but not SMA mice. These findings provide experimental evidence about the ability of nifedipine to prevent the appearance of developmental defects in SMA embryonic motor neurons in culture and reveal to which extent nifedipine could still increase neurotransmission at the NMJ in SMA mice under different functional demands.},
  language  = {en}
}
@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{WetzelJablonkaBlum2013,
  author    = {Wetzel, Andrea and Jablonka, Sibylle and Blum, Robert},
  title     = {Cell-autonomous axon growth of young motoneurons is triggered by a voltage-gated sodium channel},
  series = {Channels (Austin)},
  volume    = {7},
  journal   = {Channels (Austin)},
  number    = {1},
  doi       = {10.4161/chan.23153},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132586},
  pages     = {51-56},
  year      = {2013},
  abstract  = {Spontaneous electrical activity preceding synapse formation contributes to the precise regulation of neuronal development. Examining the origins of spontaneous activity revealed roles for neurotransmitters that depolarize neurons and activate ion channels. Recently, we identified a new molecular mechanism underlying fluctuations in spontaneous neuronal excitability. We found that embryonic motoneurons with a genetic loss of the low-threshold sodium channel Na\(_V\)1.9 show fewer fluctuations in intracellular calcium in axonal compartments and growth cones than wild-type littermates. As a consequence, axon growth of Na\(_V\)1.9-deficient motoneurons in cell culture is drastically reduced while dendritic growth and cell survival are not affected. Interestingly, Na\(_V\)1.9 function is observed under conditions that would hardly allow a ligand- or neurotransmitter-dependent depolarization. Thus, Na\(_V\)1.9 may serve as a cell-autonomous trigger for neuronal excitation. In this addendum, we discuss a model for the interplay between cell-autonomous local neuronal activity and local cytoskeleton dynamics in growth cone function.},
  language  = {en}
}