Table 1.
List of original papers that investigate proteins expressed and/or secreted by skeletal muscle which act on muscle-adipose tissue crosstalk.
| References | Experimental model | Training protocol | Myokines analyzed | Main results | Evidence of muscle-adipose tissue crosstalk |
|---|---|---|---|---|---|
| Norheim et al., 2014 | Healthy and physically inactive men | Combined strength and endurance training for 12 weeks, including two endurance bicycle sessions (60 min−70% VO2máx) and two whole body strength training sessions (60 min) per week. | FNDC5/Irisin | ↑ FNDC5 mRNA expression in skeletal muscle. ↑ Plasma concentration of irisin after 45 min ergometer cycling (~1.2-fold) and ↓ after 2 h rest. |
There was little or no effect of long-term training on selected browning genes and no correlation between circulating irisin with UCP1 mRNA in subcutaneous adipose tissue. |
| Lee et al., 2014 | Healthy adults and volunteers wearing hospital scrubs rested in beds | Acute session of exercise on cycloergometer following graded, stepwise cold exposure to maximal capacity (VO2max) and sub-maximal exercise test at 40% VO2max for 1 h. | Irisin | ↑ Irisin in maximal exercise group compared to cold exposure. | In vitro experiments (BAT) provide mechanistic insight into in vivo observations. The results indicate that shivering-stimulated irisin, in concert with FGF21, phenotypically transforms white adipocytes to BAT-like cells to expand overall thermogenic capacity. |
| Miyamoto-Mikami et al., 2015 | Healthy young subjects and healthy middle-aged/older adults | Cycling on a leg ergometer for 55 min, 3 days/week, for 8 weeks. | Irisin | ↑ Serum irisin level in the middle-aged/older training group ↔Serum irisin level in the young training group |
In the middle-aged/older training group, the endurance training-induced reduction in visceral adipose tissue area was negatively correlated with the change in serum irisin level |
| Kurdiova et al., 2014 | Middle-aged sedentary men | Combined training performed 3 times per week during 3 months. Intensity was maintained at 70–85% of maximal heart rate and strength training Intensity was maintained at 70–85% of maximal heart rate. | FNDC5/Irisin | Exercise did not affect Fndc5/irisin | Was observed a down regulation of Fndc5/irisin in adipose tissue and circulation in T2D group. |
| Roca-Rivada et al., 2013 | Lean and obese rats and obese men | Free access to the activity wheel for 1 or 3 weeks | FNDC5/Irisin | ↑ FNDC5/irisin in muscle after 3 weeks of exercise ↑ FNDC5/irisin in adipose tissue after 1 week of exercise and ↓ after 3 weeks exercise |
75% of irisin expression by skeletal muscle and 28% by AT. No correlation between expression of UCP1 in subcutaneous fat and circulating irisin |
| Pekkala et al., 2013 | Untrained and trained healthy men | Acute low-intensity aerobic exercise was performed with bicycle ergometer for 1 h at a low intensity of 50% VO2max Single resistance exercise of 5 sets of 10 repetitions in leg press until failure. Heavy-intensity endurance exercise, twice a week and combined EE and RE training |
FNDC5/irisin | ↑FNDC5 mRNA only in young men post-RE | No change in plasma level of irisin on adipose tissue. Irisin and FNDC5were not associated with glucose tolerance and being overweight, or with metabolic disturbances, respectively |
| Bueno et al., 2011 | Wistar rats | 1.5 h/day, 45 min at 9:00 AM and 45 min at 05:00 h PM, for 4 weeks. | Myostatin | ↔ In mRNA myostatin between exercised and sedentary normal diet and HFD rats | ↑ In mRNA myostatin in BAT of high-fat rats after swimming ↓ In mRNA myostatin in mesenteric AT of high-fat trained rats versus sedentary high fat diet rats |
| Hjorth et al., 2016 | Sedentary men | 12 weeks of two interval bicycle sessions (60 min, 45-minbicycle test at 70% of VO2max) and two full-body strength training sessions (60 min) per week | Myostatin | ↓mRNA myostatin in skeletal muscle after acute and long-term exercise In cultured muscle cells myostatin promoted an insulin-independent increase in glucose uptake. ↑ Enhanced rate of glucose oxidation and lactate production in muscle cells incubated with myostatin |
The expression of myostatin was correlated negatively with insulin sensitivity ↑ Myostatin mRNA in AT after 12 weeks of training and correlated positively with insulin sensitivity markers. |
| Macpherson et al., 2015 | C57BL/6 mice | Mice ran for 120 min at 15 m/min, with an incline of 5%. | IL-6 | ↑ Expression and secretion of IL-6 and IL-10 in skeletal muscle in exercise HFD group | ↑ On infiltrates cells in AT of HFD group ↓ F480 and CD11 in AT in exercise HFD group |
| Castellani et al., 2015 | C57BL/6 mice | Mice ran for 2 h at 15 m/min at a 5% incline, during 4 weeks | IL-6 | ↔ No differences in plasma IL-6 between sedentary and trained mice | ↑ In levels of il-6 mRNA epididymal AT with no increase in IL-1β and TNF-α ↑ In protein and mRNA levels of IL-6 receptor in epididymal AT |
BAT, Brown Adipose Tissue; AT, Adipose Tissue; EE, Endurance Exercise; RE, Resistance Exercise; T2D, Type 2 Diabetes; ↑, increase, ↓, decrease and ↔, no alterations.