Distinct proteasomal activity for fast and slow twitch skeletal muscle during aging
- Skeletal muscle alterations during aging lead to dysfunctional metabolism, correlating with frailty and early mortality. The loss of proteostasis is a hallmark of aging. Whether proteostasis loss plays a role in muscle aging remains elusive. To address this question we collected muscles, Soleus (SOL, type I) and Extensor digitorum longus (EDL, type II), from young (4 months) and old (25 months) C57BL/6 mice and evaluated the proteasomal system. Initial work showed decreased 26 S activity in old SOL. EDL displayed lower proteasomal activity in both ages compared to any of the SOL ages. Moreover, in order to understand if during aging there is the so-called “fiber switch from fast-to-slow”, we performed western blots against sMHC and fMHC (slow and fast myosin heavy chain, respectively). Preliminary results suggest that young SOL is composed by slow twitch fibers but also contains fast twitch fibers, while young EDL seems to be mostly composed by fast twitch fibers that level down during aging, suggesting the switch. As a conclusion,Skeletal muscle alterations during aging lead to dysfunctional metabolism, correlating with frailty and early mortality. The loss of proteostasis is a hallmark of aging. Whether proteostasis loss plays a role in muscle aging remains elusive. To address this question we collected muscles, Soleus (SOL, type I) and Extensor digitorum longus (EDL, type II), from young (4 months) and old (25 months) C57BL/6 mice and evaluated the proteasomal system. Initial work showed decreased 26 S activity in old SOL. EDL displayed lower proteasomal activity in both ages compared to any of the SOL ages. Moreover, in order to understand if during aging there is the so-called “fiber switch from fast-to-slow”, we performed western blots against sMHC and fMHC (slow and fast myosin heavy chain, respectively). Preliminary results suggest that young SOL is composed by slow twitch fibers but also contains fast twitch fibers, while young EDL seems to be mostly composed by fast twitch fibers that level down during aging, suggesting the switch. As a conclusion, EDL seems to have less proteasomal activity, however, if this is a contributor or a consequence to the muscle fiber switch during aging still needs further investigation.…
Author details: | Raquel Fernando, Cathleen Drescher, Stefanie Deubel, Tilman GruneORCiDGND, Jose Pedro CastroORCiD |
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DOI: | https://doi.org/10.1016/j.freeradbiomed.2018.04.393 |
ISSN: | 0891-5849 |
ISSN: | 1873-4596 |
Title of parent work (English): | Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research |
Publisher: | Elsevier |
Place of publishing: | New York |
Publication type: | Other |
Language: | English |
Date of first publication: | 2018/05/14 |
Publication year: | 2018 |
Release date: | 2021/11/30 |
Volume: | 120 |
Number of pages: | 1 |
First page: | S119 |
Last Page: | S119 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Ernährungswissenschaft |
DDC classification: | 6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit |