Decrease of PKB/Akt Phosphorylation is Partially Mediated by SAPK/JNK Activation in Serum-free L6 Myoblasts Starved
Mee-Young Kim1, Jeong-Uk Lee2, Ju-Hyun Kim2
1Laboratory of Health Science and Nanophysiotherapy, Department of Physical Therapy, Graduate School, Yongin University, Republic of Korea ; Laboratory of Health Science and Nanophysiotherapy, Department of Physical Therapy, Graduate School, Yongin University, Republic of Korea.
Journal of Physical Therapy Science
|December 2, 2014
Summary
Serum-free starvation significantly decreases protein kinase B/Akt phosphorylation in L6 myoblasts. This reduction is partly linked to stress-activated protein kinase/c-Jun N-terminal kinase activity.
Area of Science:
- Muscle cell biology
- Molecular signaling pathways
Background:
- Cell cultures are utilized to model muscle atrophy in various experimental settings.
- The specific impact of serum-free starvation on protein kinase B/Akt (PKB/Akt) activation in skeletal muscle cells requires further elucidation.
Purpose of the Study:
- To investigate the alterations in PKB/Akt phosphorylation within L6 myoblasts subjected to serum-free starvation.
- To understand the role of SAPK/JNK signaling in mediating these changes.
Main Methods:
- L6 myoblasts were cultured and subjected to serum-free starvation for extended periods.
- Western blotting was employed to quantify PKB/Akt expression and phosphorylation levels.
Main Results:
- A significant decrease in PKB/Akt phosphorylation was observed in starved L6 myoblasts compared to controls.
- This reduction in phosphorylation occurred progressively over 120 hours of serum-free starvation.
- Administration of SP600125, a SAPK/JNK inhibitor, partially reversed the decreased PKB/Akt phosphorylation.
Conclusions:
- Serum-free starvation in L6 myoblasts leads to diminished PKB/Akt phosphorylation.
- The observed decrease in PKB/Akt phosphorylation is, in part, mediated by the activity of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK).
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