Document Type

Journal Article

Publication Title

Medicine & Science in Sports & Exercise

Volume

54

Issue

1

First Page

89

Last Page

97

PubMed ID

34468415

Publisher

Wolters Kluwer

School

School of Medical and Health Sciences / Exercise Medicine Research Institute

RAS ID

36913

Funders

Edith Cowan University

National Institute of Arthritis and Musculo-skeletal

Skin Disease Grant

Comments

This is a non-final version of an article published in final form in Mavropalias, G., Wu, Y. F., Boppart, M. D., Blazevich, A. J., & Nosaka, K. (2022). Increases in integrin-ILK-RICTOR-Akt proteins, muscle mass, and strength after eccentric cycling training. Medicine & Science in Sports & Exercise, 54(1), 89-97. https://doi.org/10.1249/MSS.0000000000002778

Mavropalias, G., Wu, Y. F., Boppart, M. D., Blazevich, A. J., & Nosaka, K. (2022). Increases in integrin-ILK-RICTOR-Akt proteins, muscle mass, and strength after eccentric cycling training. Medicine & Science in Sports & Exercise, 54(1), 89-97.

https://doi.org/10.1249/MSS.0000000000002778

Abstract

PURPOSE:

Recently, it has been suggested that a cellular pathway composed of integrin, integrin-linked kinase (ILK), rapamycin-insensitive companion of mTOR (RICTOR), and Akt may facilitate long-term structural and functional adaptations associated with exercise, independent of the mTORC1 pathway. Therefore, we examined changes in integrin-ILK-RICTOR-Akt protein in vastus lateralis (VL) before and after 8 wk of eccentric cycling training (ECC), which was expected to increase muscle function and VL cross-sectional area (CSA).

METHODS:

Eleven men (23 ± 4 yr) completed 24 sessions of ECC with progressive increases in intensity and duration, resulting in a twofold increase in work from the first three (75.4 ± 14.1 kJ) to the last three sessions (150.7 ± 28.4 kJ). Outcome measures included lower limb lean mass, VL CSA, static strength, and peak and average cycling power output. These measures and VL samples were taken before and 4-5 d after the last training session. RESULTS: Significant (P < 0.05) increases in integrin-β1 (1.64-fold) and RICTOR (2.99-fold) protein as well as the phosphorylated-to-total ILK ratio (1.70-fold) were found, but integrin-α7 and Akt did not change. Increases in lower limb, thigh, and trunk lean mass (2.8%-5.3%, P < 0.05) and CSA (13.3% ± 9.0%, P < 0.001) were observed. Static strength (18.1% ± 10.8%) and both peak (8.6% ± 10.5%) and average power output (7.4% ± 8.3%) also increased (P < 0.05). However, no significant correlations were found between the magnitude of increases in protein and the magnitude of increases in CSA, static strength, or power output.

CONCLUSIONS:

In addition to increased muscle mass, strength, and power, we demonstrate that ECC increases integrin-β1 and RICTOR total protein and p-ILK/t-ILK, which may play a role in protection against muscle damage as well as anabolic signaling to induce muscle adaptations.

DOI

10.1249/MSS.0000000000002778

Research Themes

Society and Culture

Priority Areas

Human movement and performance

Available for download on Tuesday, January 31, 2023

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