The Akt/mTOR pathway: Data comparing young and aged mice with leucine supplementation at the onset of skeletal muscle regeneration

The data described herein is related to the article “Differential Effects of Leucine Supplementation in Young and Aged Mice at the Onset of Skeletal Muscle Regeneration” [1]. Aging is associated with a decreased ability of skeletal muscle to regenerate following injury. Leucine supplementation has been extensively shown, in young subjects, to promote protein synthesis during regeneration; however, the effects of leucine supplementation on the Akt/mTOR pathway in aged mice at the onset of muscle regeneration are not fully elucidated. In this article, we present data on the Akt/mTOR protein synthesis pathway at the onset of muscle regeneration in young and aged C57BL/6J mice that are and are not receiving leucine supplementation. More specifically, protein content of total Akt, mTOR, p70S6K and 4EBP-1 are presented. Additionally, we provide relative (phosphorylated:total) protein content comparisons of these targets as they present themselves in young and aged mice who have neither been injured nor received leucine supplementation. Lastly, markers of atrophy (FoxO1/O3, MuRF-1, Atrogin-1) are also reported in these young and aged control groups.


Subject area
Biology More specific subject area Skeletal muscle, leucine supplementation, regeneration, aging Type of data Graphs, images How data was acquired Immunoblotting, PCR

Data format Analyzed Experimental factors
Three-month and 24-month old female C57BL/6J mice received an intramuscular injection of bupivacaine or PBS and were or were not given leucine supplementation.

Experimental features
Young and aged female C57BL/6J mice received an intramuscular injection of PBS or bupivacaine in the tibialis anterior. After the injection, mice were given or not given leucine supplementation. Three days after the injection, mice were sacrificed, and the tibialis anterior was isolated, weighed and prepared for immunoblotting.

Data source location
University of Arkansas, Fayetteville, Arkansas

Data accessibility
All data are provided with this article Value of the data The data provides age-induced alterations in protein degradation and synthesis markers which gives further insight into the natural physiological changes that occur as a function of age.
Provides data on the effects of leucine supplementation on Akt/mTOR signaling proteins at the onset of skeletal muscle regeneration in an aged population which is valuable for future studies examining later time points when regeneration should be resolved.
This data will help other researchers determine the effectiveness of leucine supplementation for promoting regeneration in an aged population.

Muscle extraction and sample preparation
Three days post-injection, the TA and tibias were extracted as previously described [1,4,6]. The TA was snap frozen in liquid nitrogen and stored at À 80°C. Immediately following tissue harvest, the mouse was euthanized via exsanguination of the heart.

Statistical analyses
Results are reported as mean 7SE. Pre-planned comparison between 3 month and 24 month uninjured, untreated controls (no injury, no leucine) were conducted by Student's t-tests. Two-way ANOVAs (leucine supplementation Â injury) were conducted at each level of age to determine significant main effects and interactions (CA, SPSS 23). Post hoc analysis on significant interactions was done with a Student-Newman-Keuls test. Significance was established at an alpha level of 0.05.

Funding
This work was supported by the Claude Pepper Older Americans Independence Center (P30 AG028718).