IL-1α reversibly inhibits skeletal muscle ryanodine receptor a novel mechanism for critical illness myopathy?

Edwards JN, Weber C, Liu I, Reischl B, Most P, Wirth-Hücking A, Yi B, Friedrich O, Voelkers M, Buttgereit A, Lang R, Lee A, Polyak F, Von Wegner F, Cully TR (2014)


Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2014

Journal

Book Volume: 50

Pages Range: 1096-1106

Journal Issue: 6

DOI: 10.1165/rcmb.2013-0059OC

Open Access Link: http://www.atsjournals.org/doi/full/10.1165/rcmb.2013-0059OC

Abstract

Critical illness myopathies in patients with sepsis or sustained mechanical ventilation prolong intensive care treatment and threaten both patients and health budgets; no specific therapy is available. Underlying pathophysiological mechanisms are still patchy. We characterized IL-1α action on muscle performance in "skinned" muscle fibers using force transducers and confocal Ca fluorescence microscopy for force/Ca transients and Ca sparks. Association of IL-1α with sarcoplasmic reticulum (SR) release channel, ryanodine receptor (RyR) 1, was investigated with coimmunoprecipitation and confocal immunofluorescence colocalization. Membrane integrity was studied in single, intact fibers challenged with IL-1α. IL-1α reversibly stabilized Mg inhibition of Ca release. Low Mg-induced force and Ca transients were reversibly abolished by IL-1a. At normal Mg , IL-1α reversibly increased caffeine-induced force and Ca transients. IL-1α reduced SR Ca leak via RyR1, as judged by (1) increased SR Ca retention, (2) increased IL-1α force transients being reproduced by 25 μM tetracaine, and (3) reduced Ca spark frequencies by IL-1a or tetracaine. Coimmunoprecipitation confirmed RyR1/IL-1 association. RyR1/IL-1 immunofluorescence patterns perfectly colocalized. Long-term, 8-hour IL-1α challenge of intact muscle fibers compromised membrane integrity in approximately 50% of fibers, and confirmed intracellular IL-1α deposition. IL-1α exerts a novel, specific, and reversible interaction mechanism with the skeletal muscle RyR1 macromolecular release complex without the need to act via its membrane IL-1 receptor, as IL-1R membrane expression levels were not detectable in Western blots or immunostaining of single fibers. We present a potential explanation of how the inflammatory mediator, IL-1α, may contribute to muscle weakness in critical illness. Copyright © 2014 by the American Thoracic Society.

Authors with CRIS profile

Related research project(s)

Involved external institutions

How to cite

APA:

Edwards, J.N., Weber, C., Liu, I., Reischl, B., Most, P., Wirth-Hücking, A.,... Cully, T.R. (2014). IL-1α reversibly inhibits skeletal muscle ryanodine receptor a novel mechanism for critical illness myopathy? American journal of respiratory cell and molecular biology, 50(6), 1096-1106. https://doi.org/10.1165/rcmb.2013-0059OC

MLA:

Edwards, Joshua N., et al. "IL-1α reversibly inhibits skeletal muscle ryanodine receptor a novel mechanism for critical illness myopathy?" American journal of respiratory cell and molecular biology 50.6 (2014): 1096-1106.

BibTeX: Download