PMID- 25761522 OWN - NLM STAT- MEDLINE DCOM- 20160119 LR - 20181113 IS - 1756-6606 (Electronic) IS - 1756-6606 (Linking) VI - 8 DP - 2015 Feb 10 TI - The novel protein kinase C epsilon isoform at the adult neuromuscular synapse: location, regulation by synaptic activity-dependent muscle contraction through TrkB signaling and coupling to ACh release. PG - 8 LID - 10.1186/s13041-015-0098-x [doi] LID - 8 AB - BACKGROUND: Protein kinase C (PKC) regulates a variety of neural functions, including neurotransmitter release. Although various PKC isoforms can be expressed at the synaptic sites and specific cell distribution may contribute to their functional diversity, little is known about the isoform-specific functions of PKCs in neuromuscular synapse. The present study is designed to examine the location of the novel isoform nPKCepsilon at the neuromuscular junction (NMJ), their synaptic activity-related expression changes, its regulation by muscle contraction, and their possible involvement in acetylcholine release. RESULTS: We use immunohistochemistry and confocal microscopy to demonstrate that the novel isoform nPKCepsilon is exclusively located in the motor nerve terminals of the adult rat NMJ. We also report that electrical stimulation of synaptic inputs to the skeletal muscle significantly increased the amount of nPKCepsilon isoform as well as its phosphorylated form in the synaptic membrane, and muscle contraction is necessary for these nPKCepsilon expression changes. The results also demonstrate that synaptic activity-induced muscle contraction promotes changes in presynaptic nPKCepsilon through the brain-derived neurotrophic factor (BDNF)-mediated tyrosine kinase receptor B (TrkB) signaling. Moreover, nPKCepsilon activity results in phosphorylation of the substrate MARCKS involved in actin cytoskeleton remodeling and related with neurotransmission. Finally, blocking nPKCepsilon with a nPKCepsilon-specific translocation inhibitor peptide (epsilonV1-2) strongly reduces phorbol ester-induced ACh release potentiation, which further indicates that nPKCepsilon is involved in neurotransmission. CONCLUSIONS: Together, these results provide a mechanistic insight into how synaptic activity-induced muscle contraction could regulate the presynaptic action of the nPKCepsilon isoform and suggest that muscle contraction is an important regulatory step in TrkB signaling at the NMJ. FAU - Obis, Teresa AU - Obis T AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. teresa.obis@gmail.com. FAU - Besalduch, Nuria AU - Besalduch N AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. nbesal@yahoo.es. FAU - Hurtado, Erica AU - Hurtado E AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. erica.hurtado@urv.cat. FAU - Nadal, Laura AU - Nadal L AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. lauranadalm@gmail.com. FAU - Santafe, Manel M AU - Santafe MM AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. manuel.santafe@urv.cat. FAU - Garcia, Neus AU - Garcia N AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. ngs@fmcs.urv.es. FAU - Tomas, Marta AU - Tomas M AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. marta.tomas@urv.cat. FAU - Priego, Mercedes AU - Priego M AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. merce18pl@hotmail.com. FAU - Lanuza, Maria A AU - Lanuza MA AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. mariaangel.lanuza@urv.cat. FAU - Tomas, Josep AU - Tomas J AD - Unitat d'Histologia i Neurobiologia (UHN). Facultat de Medicina i Ciencies de la Salut, Universitat Rovira i Virgili, Sant Llorenc 21, 43201, Reus, Spain. josepmaria.tomas@urv.cat. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20150210 PL - England TA - Mol Brain JT - Molecular brain JID - 101468876 RN - 0 (Intracellular Signaling Peptides and Proteins) RN - 0 (Isoenzymes) RN - 0 (Marcks protein, rat) RN - 0 (Membrane Proteins) RN - 125267-21-2 (Myristoylated Alanine-Rich C Kinase Substrate) RN - EC 2.7.10.1 (Receptor, trkB) RN - EC 2.7.11.13 (Protein Kinase C-epsilon) RN - N9YNS0M02X (Acetylcholine) RN - NI40JAQ945 (Tetradecanoylphorbol Acetate) SB - IM MH - Acetylcholine/*metabolism MH - Aging/*metabolism MH - Animals MH - Animals, Newborn MH - Electrophysiological Phenomena/drug effects MH - Intracellular Signaling Peptides and Proteins/metabolism MH - Isoenzymes/metabolism MH - Male MH - Membrane Proteins/metabolism MH - Models, Biological MH - *Muscle Contraction/drug effects MH - Muscle, Skeletal/drug effects/metabolism MH - Myristoylated Alanine-Rich C Kinase Substrate MH - Neuromuscular Junction/drug effects/*enzymology MH - Phosphorylation/drug effects MH - Protein Kinase C-epsilon/*metabolism MH - Rats, Sprague-Dawley MH - Receptor, trkB/*metabolism MH - Signal Transduction/drug effects MH - Synapses/drug effects/*enzymology MH - Tetradecanoylphorbol Acetate/pharmacology PMC - PMC4348107 EDAT- 2015/03/13 06:00 MHDA- 2016/01/20 06:00 PMCR- 2015/02/10 CRDT- 2015/03/13 06:00 PHST- 2014/11/10 00:00 [received] PHST- 2015/01/16 00:00 [accepted] PHST- 2015/03/13 06:00 [entrez] PHST- 2015/03/13 06:00 [pubmed] PHST- 2016/01/20 06:00 [medline] PHST- 2015/02/10 00:00 [pmc-release] AID - s13041-015-0098-x [pii] AID - 98 [pii] AID - 10.1186/s13041-015-0098-x [doi] PST - epublish SO - Mol Brain. 2015 Feb 10;8:8. doi: 10.1186/s13041-015-0098-x.