Table 2.
Adipokine | Association with obesity and/or T2D in humans | Adipokine effect on insulin signalling in animal models | Adipokine effect on insulin signalling in human skeletal muscle | |
---|---|---|---|---|
In Vivo | In Vitro | |||
FGF-21 | Increased [86]. | Increased insulin sensitivity and glucose uptake in mice, via FGF-21 mediated increases in adiponectin production and secretion from adipocytes [76]. | 6 h incubation of mouse EDL muscle with FGF-21 resulted in a 54% increase in insulin stimulated glucose uptake [86]. | Directly increased glucose uptake in primary human myotubes [86]. Prevents palmitate-induced insulin resistance in primary human myotubes by inhibiting stress kinases and NF-κB [87]. |
Continuous cerebral administration for 2 weeks increased whole body insulin sensitivity in rats with dietary induced obesity [77]. | ||||
Daily administration for 6 weeks improved glucose handling in diabetic rhesus monkeys [78]. | ||||
Chemerin | Increased [94, 138]. | Overexpression increased insulin resistance in LDL receptor deficient mice by reducing AKT phosphorylation in response to insulin in skeletal muscle, but not liver or pancreas [96]. | 24 h pre-treatment reduces insulin stimulated glucose uptake in C2C12 myotubes in a dose dependent manor [99]. | 24 h chemerin Increased insulin resistance and reduced insulin stimulated glucose uptake in primary human myotubes, mediated by increased ERK signalling [95]. |
knockout mice display increased skeletal muscle insulin resistance while transgenic mice exhibit increased skeletal muscle insulin resistance [98]. | ||||
Acute chemerin treatment exacerbated glucose intolerance and lowered serum insulin levels in obese and diabetic mice. No effect observed in normoglycemic mice [97]. | ||||
CTRP3 | Decreased [115, 116, 139]. | Administration of recombinant CTRP3 directly lowers glucose levels in normal and insulin-resistant ob/ob mice [140]. | Administration of recombinant CTRP3 to L6 myotubes had no effect on glucose uptake [140]. | Unknown |
Overexpression of CTRP3 improved insulin sensitivity in HFD fed mice [141]. | Increased glucose uptake and GLUT 4 mRNA expression in insulin resistant adipocytes [142]. | |||
RBP4 | Increased [143, 144]. | Overexpression or direct administration of RBP4 increased insulin resistance in mice. RBP4 knockout improves insulin sensitivity in mice [144]. | unknown | Unknown |
Reducing circulating RBP4 in obese mice models improved glucose tolerance and increased insulin stimulated glucose uptake in skeletal muscle up to 60% [145]. | ||||
Vaspin | Increased [65, 67, 68]. | Vaspin treatment increased insulin sensitivity and glucose tolerance in obese and diabetic mice [59, 60]. | Unknown | Unknown |
transgenic mice overexpressing vaspin displayed improved glucose tolerance and were protected from obesity when challenged with a high fat diet [62]. | ||||
Pref-1 | Increased [101]. | Overexpression in mice drives insulin resistance via decreased adipose tissue and skeletal muscle glucose uptake and impaired skeletal muscle insulin signalling [105]. | Unknown | 4 Day exposure to primary human myotubes from lean, obese and T2D subjects had no effect on glucose uptake [106]. |
Follistatin-like 1 | Increased [108]. | Unknown | Blunts insulin signalling-adipocytes [108]. | unknown |
Omentin-1 | Decreased [146, 147]. | Unknown | omentin-1 induced AKT phosphorylation and enhanced insulin-stimulated glucose uptake in human adipocytes [123]. | Unknown Unknown |
Lipocallin-14 | Unknown | Over expression in diet induced obese mice reduced glucose and insulin levels while improving glucose tolerance [124]. | Unknown |