BAIBA Does Not Regulate UCP-3 Expression in Human Skeletal Muscle as a Response to Aerobic Exercise.
β-Aminoisobutyric acid (BAIBA) has shown to modulate uncoupling protein (UCP)-1 expression, which is mainly expressed in white adipose tissue; however, no studies to date have analyzed its potential effect on the main uncoupling protein of skeletal muscle, UCP-3. The main goal of this study was to assess the potential effect of acute aerobic exercise on serum BAIBA and skeletal muscle UCP-3. The secondary goal was to assess the potential involvement of the transcription factors proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and peroxisome proliferator-activated receptor alpha (PPARα), as well as free fatty acids (FFAs) in UCP-3 expression. A tertiary goal of the study was to evaluate the potential effect of consuming a preexercise meal on the outcome of the first 2 objectives.



In a randomized crossover design, untrained participants performed 2 acute cycling sessions (350 kcal at 70% of their VO2peak) after 2 experimental conditions: (1) consumption of a multi-macronutrient shake and (2) a fasting period of 8 hours. Blood samples were taken at baseline, preexercise, postexercise, 1 hour, and 4 hours postexercise, and muscle biopsies were taken at the last 4 time points. UCP-3 protein concentration and expression, as well as the mRNA expression of PGC-1α and PPARα, were measured in muscle, and BAIBA, glucose, and FFA were measured in serum.



Aerobic exercise failed to induce a significant effect on serum BAIBA, PGC-1α, and PPARα regardless on the feeding condition. Despite the lack of effect of exercise on the previous variables, UCP-3 expression and protein concentration significantly increased in the shake condition.



The expression of human skeletal muscle UCP-3 as a result of exercise might be controlled by factors other than BAIBA.
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Flor E
FE
Morales
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Jeffrey S
JS
Forsse
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Thomas L
TL
Andre
b Department of Health , Kinesiology and Sport, University of South Alabama , Mobile , Alabama.
Sarah K
SK
McKinley-Barnard
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Paul S
PS
Hwang
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Ian G
IG
Anthony
c Department of Kinesiology and Sport Management , Texas Tech University , Lubbock , Texas.
Grant M
GM
Tinsley
d Department of Nutrition , Tecnológico de Monterrey , Monterrey , N.L. , México.
Mike
M
Spillane
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Peter W
PW
Grandjean
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Alejandro
A
Ramirez
a Department of Health , Human Performance and Recreation, Baylor University , Waco , Texas.
Darryn S
DS
Willoughby
D000293:Adolescent; D000328:Adult; D000621:Aminoisobutyric Acids / Q000494:pharmacology*; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000071247:Uncoupling Protein 3 / Q000235:genetics / Q000378:metabolism*; D055815:Young Adult
D000621:Aminoisobutyric Acids; D014157:Transcription Factors; C000604392:UCP3 protein, human; D000071247:Uncoupling Protein 3; C033435:3-aminoisobutyric acid
Uncoupling protein 3; aerobic exercise; beta-aminoisobutyric acid; fasted; free fatty acids; glucose