Page 8 - 《运动与健康科学》(英文)2024年第2期

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Journal of Sport and Health Science 13 (2024) 130132

Commentary

TaggedAPTARAH1Considerations for exerkine research focusing on the response

to exercise trainingTaggedAPTARAEnd
a
TaggedAPTARAPIan A.J. Darragh , Brendan Egan a,b, *TaggedAPTARAEnd
a
TaggedAPTARAP School of Health and Human Performance, Dublin City University, Glasnevin, Dublin D09 V209, Ireland
b
Florida Institute for Human and Machine Cognition, Pensacola, FL 32502, USA
TaggedAPTARAEnd Received 16 October 2023; accepted 24 October 2023
Available online 4 November 2023
2095-2546/Ó 2024 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license.
(http://creativecommons.org/licenses/by-nc-nd/4.0/)

TaggedAPTARAPGarc ıa-Hermoso and colleagues 1 recently published a TaggedAPTARAH1Discordance between the response to acute exercise and
systematic literature review and meta-analysis on exercise exercise trainingTaggedAPTARAEnd
training-induced changes in exerkine concentrations in type 2
TaggedAPTARAPSome exerkines are pleiotropic molecules in the sense that
diabetes mellitus patients, providing a contemporary view on
they can be released from different cell types under different
how exerkines respond to exercise training. That review
conditions/stimuli and elicit varying physiological effects
prompted us to highlight 2 additional considerations that
depending on the context of their release. For example, inter-
should be taken into account when studying the response of 4
leukin-6 (IL-6) is released from activated macrophages and
exerkines to exercise training. Firstly, whether exerkines can
adipocytes within adipose tissue to elicit proinflammatory
exhibit discordant responses to acute exercise compared to 5 4,5
effects, and consequent insulin resistance. IL-6 is also
exercise training, and secondly, the need to consider the
released from contracting skeletal muscle during acute exer-
residual effects of the most recent exercise bout.TaggedAPTARAEnd
cise, with resultant effects including potentiating insulin secre-
TaggedAPTARAPThe term “exerkine” has been operationally defined as “a
tion and action, enhancing glucose uptake, and increasing fat
signaling moiety released in response to acute exercise and/or 6
oxidation. In contrast to acute exercise where circulating IL-6
chronic exercise, exerting its effects through endocrine, para-
concentrations increase, Garc ıa-Hermoso and colleagues’
crine, and/or autocrine pathways”, and encompasses “a broad 1
analysis found that circulating IL-6 concentrations decrease
range of signaling moieties, including cytokines, nucleic acids
at rest in response to exercise training. In fact, the exercise
(microRNA, mRNA, and mitochondrial DNA), lipids, and
training-induced decreases in resting IL-6 concentrations were
metabolites, which are frequently driven by cell-specific extra-
2 positively correlated with a decrease in hemoglobin A1c
cellular vesicle secretion”. To date, most exerkine research
(b = 0.44, p = 0.012). Therefore, despite the increase in circu-
has focused on molecules that have circulating concentrations lating IL-6 stimulated by acute exercise contributing to whole
that are increased in response to acute exercise. 2,3 Whether
body glucose control during and after acute exercise, a
there are changes in resting concentrations of exerkines as a
decrease in resting IL-6 concentration in response to exercise
consequence of exercise training is an important question for
training is also associated with improvements in glucose
the field. For example, health benefits conveyed by exerkines 6
control. Release of IL-6 from skeletal muscle is negligible at
may be limited to the effects of acute exercise whereby exer- 7
rest. Therefore the decreases in circulating IL-6 elicited by
kines function through stimulating transient changes in tissue
exercise training is likely caused by lower IL-6 release from
metabolism via signal transduction and/or altered gene expre- 8
non-muscle sources such as adipose tissue which when
ssion. Alternatively, exerkines could play a more comprehen-
present and indicative of chronic, subclinical inflammation
sive role in conveying the benefits of exercise whereby exercise 9
can contribute to tissue-specific insulin resistance. A similar
training induces altered exerkine profiles at rest that lead to
example is fetuin-A, a liver- and adipose tissue-derived glyco-
more persistent changes in tissue metabolism and/or signaling,
3 protein whose elevated concentration is associated with insulin
thereby creating a more prolonged time course of benefit. TaggedAPTARAEnd 10
resistance. Circulating concentration of fetuin-A is tran-
siently elevated by a single bout of exercise before returning
TaggedAPTARAEndTaggedAPTARAEnd Peer review under responsibility of Shanghai University of Sport. 11
TaggedAPTARAEnd* Corresponding author. to baseline after 24 h, yet is decreased in response to exercise
1
E-mail address: brendan.egan@dcu.ie (B. Egan). training. TaggedAPTARAEnd
https://doi.org/10.1016/j.jshs.2023.11.002
Cite this article: Darragh IAJ, Egan B. Considerations for exerkine research focusing on the response to exercise training. J Sport Health Sci 2024;13:1302.