title: Skeletal muscle calpain acts through nitric oxide and neural miRNAs to regulate acetylcholine release in motor nerve terminals.
abstract: Cholinergic overactivity in diseases of neuromuscular transmission elicits a retrograde signal resembling homeostatic synaptic plasticity that downregulates transmitter release. Understanding this compensatory pathway could provide insights into novel therapeutic avenues and molecular mechanisms underlying learning and memory. Here we identify nitric oxide as a possible source of this signal in pathological human and mouse muscle samples and link this signaling pathway to changes in synaptic function in the neuromuscular junction. We further show that neuronal nitric oxide synthase is regulated by cholinergic excess through activation of skeletal muscle calpain and its effect on Cdk5 and CaMKII, leading to direct modulation of presynaptic function. Finally, we show that this signaling pathway acts through specific miRNA control of presynaptic vesicle protein expression. The control of presynaptic miRNA levels by postsynaptic activity represents a novel mechanism for the modulation of synaptic activity in normal or pathological conditions.
authors.affiliation: Department of Neurology, University of Chicago Medical Center, Chicago, IL 60637, USA.
authors.forename: Haipeng
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
authors.forename: Bula
authors.initials: B
authors.lastname: Bhattacharyya
authors.affiliation: Departments of Neurology and Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, PA. 19104-4318.
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Neurology, University of Chicago Medical Center, Chicago, IL 60637, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Gomez
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002154:Calpain / Q000502:physiology*; D002460:Cell Line; D045744:Cell Line, Tumor; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000502:physiology*; D009046:Motor Neurons / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*
chemical_list: D035683:MicroRNAs; D009569:Nitric Oxide; D002154:Calpain; D000109:Acetylcholine