title: Retrograde regulation of motoneuron differentiation by muscle beta-catenin.
abstract: Synapse formation requires proper interaction between pre- and postsynaptic cells. In anterograde signaling, neurons release factors to guide postsynaptic differentiation. However, less is known about how postsynaptic targets retrogradely regulate presynaptic differentiation or function. We found that muscle-specific conditional knockout of beta-catenin (Ctnnb1, also known as beta-cat) in mice caused both morphologic and functional defects in motoneuron terminals of neuromuscular junctions (NMJs). In the absence of muscle beta-catenin, acetylcholine receptor clusters were increased in size and distributed throughout a wider region. Primary nerve branches were mislocated, whereas secondary or intramuscular nerve branches were elongated and reduced in number. Both spontaneous and evoked neurotransmitter release was reduced at the mutant NMJs. Furthermore, short-term plasticity and calcium sensitivity of neurotransmitter release were compromised in beta-catenin-deficient muscle. In contrast, the NMJ was normal in morphology and function in motoneuron-specific beta-catenin-deficient mice. Taken together, these observations indicate a role for muscle beta-catenin in presynaptic differentiation and function, identifying a previously unknown retrograde signaling in the synapse formation and synaptic plasticity.
authors.affiliation: Program of Developmental Neurobiology, Institute of Molecular Medicine and Genetics, Department of Neurology, Medical College of Georgia, 1120 15th Street, Augusta, Georgia 30912, USA.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Li
authors.forename: Xian-Ping
authors.initials: XP
authors.lastname: Dong
authors.forename: Shi-Wen
authors.initials: SW
authors.lastname: Luo
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Dae-Hoon
authors.initials: DH
authors.lastname: Lee
authors.forename: Annie K L
authors.initials: AK
authors.lastname: Ting
authors.forename: Hannah
authors.initials: H
authors.lastname: Neiswender
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Kim
authors.forename: Ezekiel
authors.initials: E
authors.lastname: Carpenter-Hyland
authors.forename: Tian-Ming
authors.initials: TM
authors.lastname: Gao
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Xiong
authors.forename: Lin
authors.initials: L
authors.lastname: Mei
mesh_terms: D000818:Animals; D001370:Axonal Transport / Q000235:genetics; D002450:Cell Communication / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics*; D020439:Growth Cones / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D018345:Mice, Knockout; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000002:abnormalities* / Q000294:innervation* / Q000378:metabolism; D009421:Nervous System Malformations / Q000235:genetics / Q000378:metabolism; D009469:Neuromuscular Junction / Q000002:abnormalities*; D009473:Neuronal Plasticity / Q000235:genetics; D018377:Neurotransmitter Agents / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D011940:Receptor Aggregation / Q000235:genetics; D011950:Receptors, Cholinergic / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D018377:Neurotransmitter Agents; D011950:Receptors, Cholinergic; D051176:beta Catenin