Myosin Light Chain Kinase (MLCK) Gene Influences Exercise Induced Muscle Damage during a Competitive Marathon

Myosin light chain kinase (MLCK) phosphorylates the regulatory light chain (RLC) of myosin producing increases in force development during skeletal muscle contraction. It has been suggested that MLCK gene polymorphisms might alter RLC phosphorylation thereby decreasing the ability to produce force and to resist strain during voluntary muscle contractions. Thus, the genetic variations in the MLCK gene might predispose some individuals to higher values of muscle damage during exercise, especially during endurance competitions. The aim of this investigation was to determine the influence of MLCK genetic variants on exercise-induced muscle damage produced during a marathon. Sixty-seven experienced runners competed in a marathon race. The MLCK genotype (C37885A) of these marathoners was determined. Before and after the race, a sample of venous blood was obtained to assess changes in serum myoglobin concentrations and leg muscle power changes were measured during a countermovement jump. Self-reported leg muscle pain and fatigue were determined by questionnaires. A total of 59 marathoners (88.1%) were CC homozygotes and 8 marathoners (11.9%) were CA heterozygotes. The two groups of participants completed the race with a similar time (228 ± 33 vs 234 ± 39 min; P = 0.30) and similar self-reported values for fatigue (15 ± 2 vs 16 ± 2 A.U.; P = 0.21) and lower-limb muscle pain (6.2 ± 1.7 vs 6.6 ± 1.8 cm; P = 0.29). However, CC marathoners presented higher serum myoglobin concentrations (739 ± 792 vs 348 ± 144 μg·mL-1; P = 0.03) and greater pre-to-post- race leg muscle power reduction (-32.7 ± 15.7 vs -21.2 ± 21.6%; P = 0.05) than CA marathoners. CA heterozygotes for MLCK C37885A might present higher exercise-induced muscle damage after a marathon competition than CC counterparts.

Citation: Del Coso J, Valero M, Lara B, Salinero JJ, Gallo-Salazar C, Areces F (2016) Myosin Light Chain Kinase (MLCK) Gene Influences Exercise Induced Muscle Damage during a Competitive Marathon. PLoS ONE 11(8):
e0160053.

https://doi.org/10.1371/journal.pone.0160053

Editor: Christopher R. Weber, University of Chicago, UNITED STATES

Received: February 29, 2016; Accepted: July 13, 2016; Published: August 2, 2016

Copyright: © 2016 Del Coso et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: Data are available from the Camilo Jose Cela Ethics Committee for researchers who meet the criteria for access to confidential data. The contact for the Camilo Jose Cela Ethics Committee where requests for data may be sent is: flopez@ucjc.edu.

Funding: The study was supported by a Grant-in-aid from the Vice-Rectorate of Research and Science, at the Camilo Jose Cela University. This in an internal grant given by the university to the scientists of the own university (2014/003) (http://www.ucjc.edu/la-universidad/estructura-academica/vicerrectorados/vicerrectorado-de-innovacion/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

This research explores how genetic variations in MLCK affect muscle damage in marathon runners.