Subcutaneous adipose tissue sclerostin is reduced and Wnt signaling is enhanced following 4‐weeks of sprint interval training in young men with obesity

• Published in: Physiological reports Vol. 10; no. 6; pp. e15232 - n/a
• Main Authors: Kurgan, Nigel, Islam, Hashim, Matusiak, Jennifer B. L., Baranowski, Bradley J., Stoikos, Joshua, Fajardo, Val A., MacPherson, Rebecca E. K., Gurd, Brendon J., Klentrou, Panagiota
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-03-2022; John Wiley and Sons Inc; Wiley
• Subjects: Adipocytes; Adipose tissue; beta Catenin - metabolism; Biopsy; Biosynthesis; Body fat; Bone growth; Bone mass; bone–adipose tissue crosstalk; Carbohydrates; Catenin; Exercise; Fitness training programs; Gene expression; High-Intensity Interval Training; Humans; Insulin resistance; Interleukin 6; Interval training; Laboratories; Male; Metabolism; Obesity; Obesity - therapy; Original; Osteocytes; Osteogenesis; Phosphorylation; Physical fitness; Physical training; Proteins; sclerostin; SOST protein; sprint interval training; Subcutaneous Fat - metabolism; Wnt protein; Wnt signaling; Wnt Signaling Pathway; bone-adipose tissue crosstalk; Wnt signaling; sprint interval training; sclerostin
• ISSN: 2051-817X; 2051-817X
• DOI: 10.14814/phy2.15232

Sclerostin is a Wnt/β‐catenin antagonist, mainly secreted by osteocytes, and most known for its role in reducing bone formation. Studies in rodents suggest sclerostin can also regulate adipose tissue mass and metabolism, representing bone–adipose tissue crosstalk. Exercise training has been shown to reduce plasma sclerostin levels; but the effects of exercise on sclerostin and Wnt/β‐catenin signaling specifically within adipose tissue has yet to be examined. The purpose of this study was to examine subcutaneous WAT (scWAT) sclerostin content and Wnt signaling in response to exercise training in young men with obesity. To this end, 7 male participants (BMI = 35 ± 4; 25 ± 4 years) underwent 4 weeks of sprint interval training (SIT) involving 4 weekly sessions consisting of a 5‐min warmup, followed by 8 × 20 s intervals at 170% of work rate at VO2peak, separated by 10 s of rest. Serum and scWAT were sampled at rest both pre‐ and post‐SIT. Despite no changes in serum sclerostin levels, we found a significant decrease in adipose sclerostin content (−37%, p = 0.04), an increase in total β‐catenin (+52%, p = 0.03), and no changes in GSK3β serine 9 phosphorylation. There were also concomitant reductions in serum TNF‐α (−0.36 pg/ml, p = 0.03) and IL‐6 (−1.44 pg/ml, p = 0.05) as well as an increase in VO2peak (+5%, p = 0.03) and scWAT COXIV protein content (+95%, p = 0.04). In conclusion, scWAT sclerostin content was reduced and β‐catenin content was increased following SIT in young men with excess adiposity, suggesting a role of sclerostin in regulating human adipose tissue in response to exercise training.
In this study, we examined sclerostin content in serum and subcutaneous adipose tissue both pre‐ and post‐exercise training in humans with obesity. Our data support that sclerostin decreases while Wnt/β signaling, the pathway sclerostin antagonizes, increases in adipose tissue fol. These results provide observational evidence for an endocrine role of sclerostin in humans and suggest a role of sclerostin/Wnt signaling in exercise induced adipose tissue adaptations.