title: Myocardial Infarction Causes Transient Cholinergic Transdifferentiation of Cardiac Sympathetic Nerves via gp130.
abstract: Sympathetic and parasympathetic control of the heart is a classic example of norepinephrine (NE) and acetylcholine (ACh) triggering opposing actions. Sympathetic NE increases heart rate and contractility through activation of β receptors, whereas parasympathetic ACh slows the heart through muscarinic receptors. Sympathetic neurons can undergo a developmental transition from production of NE to ACh and we provide evidence that mouse cardiac sympathetic nerves transiently produce ACh after myocardial infarction (MI). ACh levels increased in viable heart tissue 10-14 d after MI, returning to control levels at 21 d, whereas NE levels were stable. At the same time, the genes required for ACh synthesis increased in stellate ganglia, which contain most of the sympathetic neurons projecting to the heart. Immunohistochemistry 14 d after MI revealed choline acetyltransferase (ChAT) in stellate sympathetic neurons and vesicular ACh transporter immunoreactivity in tyrosine hydroxylase-positive cardiac sympathetic fibers. Finally, selective deletion of the ChAT gene from adult sympathetic neurons prevented the infarction-induced increase in cardiac ACh. Deletion of the gp130 cytokine receptor from sympathetic neurons prevented the induction of cholinergic genes after MI, suggesting that inflammatory cytokines induce the transient acquisition of a cholinergic phenotype in cardiac sympathetic neurons. Ex vivo experiments examining the effect of NE and ACh on rabbit cardiac action potential duration revealed that ACh blunted both the NE-stimulated decrease in cardiac action potential duration and increase in myocyte calcium transients. This raises the possibility that sympathetic co-release of ACh and NE may impair adaptation to high heart rates and increase arrhythmia susceptibility.
  
  
  CONCLUSIONS
  Sympathetic neurons normally make norepinephrine (NE), which increases heart rate and the contractility of cardiac myocytes. We found that, after myocardial infarction, the sympathetic neurons innervating the heart begin to make acetylcholine (ACh), which slows heart rate and decreases contractility. Several lines of evidence confirmed that the source of ACh was sympathetic nerves rather than parasympathetic nerves that are the normal source of ACh in the heart. Global application of NE with or without ACh to ex vivo hearts showed that ACh partially reversed the NE-stimulated decrease in cardiac action potential duration and increase in myocyte calcium transients. That suggests that sympathetic co-release of ACh and NE may impair adaptation to high heart rates and increase arrhythmia susceptibility.
authors.affiliation: Department of Physiology and Pharmacology and.
authors.forename: Antoinette
authors.identifier: http://orcid.org/0000-0001-5703-2298
authors.initials: A
authors.lastname: Olivas
authors.affiliation: Department of Physiology and Pharmacology and Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon 97239, and.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Gardner
authors.affiliation: Department of Pharmacology, University of California, Davis, California 95616.
authors.forename: Lianguo
authors.identifier: http://orcid.org/0000-0002-4747-0419
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Pharmacology, University of California, Davis, California 95616.
authors.forename: Crystal M
authors.initials: CM
authors.lastname: Ripplinger
authors.affiliation: Department of Physiology and Pharmacology and.
authors.forename: William R
authors.initials: WR
authors.lastname: Woodward
authors.affiliation: Department of Physiology and Pharmacology and Knight Cardiovascular Institute, Oregon Health and Science University, Portland, Oregon 97239, and habecker@ohsu.edu.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Habecker
mesh_terms: D000109:Acetylcholine / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D054338:Cell Transdifferentiation / Q000235:genetics / Q000502:physiology*; D002795:Choline O-Acetyltransferase / Q000172:deficiency / Q000235:genetics; D050822:Cytokine Receptor gp130 / Q000378:metabolism*; D004195:Disease Models, Animal; D004299:Dopamine beta-Hydroxylase / Q000235:genetics / Q000378:metabolism; D005260:Female; D005728:Ganglia, Sympathetic / Q000378:metabolism*; D005838:Genotype; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D015428:Myocardial Reperfusion Injury / Q000473:pathology* / Q000503:physiopathology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism / Q000494:pharmacology; D011817:Rabbits; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D050494:Vesicular Acetylcholine Transport Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D050494:Vesicular Acetylcholine Transport Proteins; D050822:Cytokine Receptor gp130; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine; D009638:Norepinephrine
keywords: cholinergic; cytokine; myocardial infarction; sympathetic; transdifferentiation