Effects of physical exercise on myokines expression and brown adipose-like phenotype modulation in rats fed a high-fat diet.
OBJECTIVE
Exercise-stimulated myokine secretion into circulation may be related with browning in white adipose tissue (WAT), representing a positive metabolic effect on whole-body fat mass. However, limited information is yet available regarding the impact of exercise on myokine-related modulation of adipocyte phenotype in WAT from obese rats.


METHODS
Sprague-Dawley rats (n=60) were divided into sedentary and voluntary physical activity (VPA) groups and fed with standard (35kcal% fat) or high-fat (HFD, 71kcal% fat)-isoenergetic diets. The VPA-groups had unrestricted access to wheel running throughout the protocol. After-9weeks, half of sedentary standard (SS) and sedentary HFD (HS)-fed animals were exercised on treadmill (endurance training, ET) for 8-weeks while maintaining the dietary treatments.


RESULTS
The adipocyte hypertrophy induced by HFD were attenuated by VPA and ET. HFD decreased 5' AMP-activated protein kinase (AMPK) activity in muscle as well as peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and uncoupling protein 1 (UCP1) proteins in eWAT, while not affecting circulating irisin. VPA increased eWAT Tmem26 mRNA levels in the standard diet-fed group, whereas ET increased AMPK, interleukin 6 (IL-6) and fibronectin type III domain-containing protein 5 (FNDC5) protein expression in muscle, but had no impact on circulating irisin protein content. In eWAT, ET increased bone morphogenetic protein 7 (Bmp7), Cidea and PGC-1α in both diet-fed animals, whereas BMP7, Prdm16, UCP1 and FNDC5 only in standard diet-fed group.


CONCLUSIONS
Data suggest that ET-induced myokine production seems to contribute, at least in part, to the "brown-like" phenotype in WAT from rats fed a HFD.
CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal. Electronic address: silviadarocharodrigues@gmail.com.
Sílvia
S
Rocha-Rodrigues
Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; Obesity & Adipobiology Group, Instituto de Investigación Sanitario de Navarra (IdiSNA), Pamplona, Spain; CIBEROBN, Instituto de Salud Carlos III, Pamplona, Spain.
Amaia
A
Rodríguez
Department of Experimental Biology, Faculty of Medicine, University of Porto, Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Institute for Molecular and Cell Biology (IBMC), University of Porto, Porto, Portugal.
Alexandra M
AM
Gouveia
CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal.
Inês O
IO
Gonçalves
Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; Obesity & Adipobiology Group, Instituto de Investigación Sanitario de Navarra (IdiSNA), Pamplona, Spain; CIBEROBN, Instituto de Salud Carlos III, Pamplona, Spain.
Sara
S
Becerril
Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; Obesity & Adipobiology Group, Instituto de Investigación Sanitario de Navarra (IdiSNA), Pamplona, Spain; CIBEROBN, Instituto de Salud Carlos III, Pamplona, Spain.
Beatriz
B
Ramírez
CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal.
Jorge
J
Beleza
Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain; Department of Endocrinology & Nutrition, Clínica Universidad de Navarra, Pamplona, Spain; Obesity & Adipobiology Group, Instituto de Investigación Sanitario de Navarra (IdiSNA), Pamplona, Spain; CIBEROBN, Instituto de Salud Carlos III, Pamplona, Spain.
Gema
G
Frühbeck
CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal.
António
A
Ascensão
CIAFEL - Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal.
José
J
Magalhães
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D050154:Adiposity; D000818:Animals; D001835:Body Weight; D016207:Cytokines / Q000378:metabolism*; D059305:Diet, High-Fat; D004734:Energy Metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D010641:Phenotype; D010805:Physical Conditioning, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley
D016207:Cytokines
Adiposity; Browning; Endurance training; FNDC5/irisin; IL-6; Skeletal muscle; UCP1