TY  - JOUR
A1  - Tejero, Rocio
A1  - Alsakkal, Mohammad
A1  - Hennlein, Luisa
A1  - Lopez-Cabello, Ana M.
A1  - Jablonka, Sibylle
A1  - Tabares, Lucia
T1  - Nifedipine ameliorates cellular differentiation defects of Smn-deficient motor neurons and enhances neuromuscular transmission in SMA mice
JF  - International Journal of Molecular Sciences
N2  - 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.
KW  - spinal muscular atrophy
KW  - motor neurons
KW  - synaptic transmission
KW  - neuromuscular junction
KW  - calcium channels
KW  - nifedipine
KW  - growth cone
KW  - axons
KW  - synaptic vesicles
KW  - postsynaptic potentials
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313636
SN  - 1422-0067
VL  - 24
IS  - 8
ER  - 
TY  - JOUR
A1  - Lüningschrör, Patrick
A1  - Binotti, Beyenech
A1  - Dombert, Benjamin
A1  - Heimann, Peter
A1  - Perez-Lara, Angel
A1  - Slotta, Carsten
A1  - Thau-Habermann, Nadine
A1  - von Collenberg, Cora R.
A1  - Karl, Franziska
A1  - Damme, Markus
A1  - Horowitz, Arie
A1  - Maystadt, Isabelle
A1  - Füchtbauer, Annette
A1  - Füchtbauer, Ernst-Martin
A1  - Jablonka, Sibylle
A1  - Blum, Robert
A1  - Üçeyler, Nurcan
A1  - Petri, Susanne
A1  - Kaltschmidt, Barbara
A1  - Jahn, Reinhard
A1  - Kaltschmidt, Christian
A1  - Sendtner, Michael
T1  - Plekhg5-regulated autophagy of synaptic vesicles reveals a pathogenic mechanism in motoneuron disease
JF  - Nature Communications
N2  - Autophagy-mediated degradation of synaptic components maintains synaptic homeostasis but also constitutes a mechanism of neurodegeneration. It is unclear how autophagy of synaptic vesicles and components of presynaptic active zones is regulated. Here, we show that Pleckstrin homology containing family member 5 (Plekhg5) modulates autophagy of synaptic vesicles in axon terminals of motoneurons via its function as a guanine exchange factor for Rab26, a small GTPase that specifically directs synaptic vesicles to preautophagosomal structures. Plekhg5 gene inactivation in mice results in a late-onset motoneuron disease, characterized by degeneration of axon terminals. Plekhg5-depleted cultured motoneurons show defective axon growth and impaired autophagy of synaptic vesicles, which can be rescued by constitutively active Rab26. These findings define a mechanism for regulating autophagy in neurons that specifically targets synaptic vesicles. Disruption of this mechanism may contribute to the pathophysiology of several forms of motoneuron disease.
KW  - autophagy
KW  - synaptic vesicles
KW  - Pleckstrin homology containing family member 5 (Plekhg5)
KW  - regulation
KW  - motoneuron disease
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170048
VL  - 8
IS  - 678
ER  -