Deletion of the gene encoding G0/G 1 switch protein 2 (G0s2) alleviates high-fat-diet-induced weight gain and insulin resistance, and promotes browning of white adipose tissue in mice.
OBJECTIVE
Obesity is a global epidemic resulting from increased energy intake, which alters energy homeostasis and results in an imbalance in fat storage and breakdown. G0/G1 switch gene 2 (G0s2) has been recently characterised in vitro as an inhibitor of adipose triglyceride lipase (ATGL), the rate-limiting step in fat catabolism. In the current study we aim to functionally characterise G0s2 within the physiological context of a mouse model.


METHODS
We generated a mouse model in which G0s2 was deleted. The homozygous G0s2 knockout (G0s2 (-/-)) mice were studied over a period of 22 weeks. Metabolic variables were measured including body weight and body composition, food intake, glucose and insulin tolerance tests, energy metabolism and thermogenesis.


RESULTS
We report that G0s2 inhibits ATGL and regulates lipolysis and energy metabolism in vivo. G0s2 (-/-) mice are lean, resistant to weight gain induced by a high-fat diet and are glucose tolerant and insulin sensitive. The white adipose tissue of G0s2 (-/-) mice has enhanced lipase activity and adipocytes showed enhanced stimulated lipolysis. Energy metabolism in the G0s2 (-/-) mice is shifted towards enhanced lipid metabolism and increased thermogenesis. G0s2 (-/-) mice showed enhanced cold tolerance and increased expression of thermoregulatory and oxidation genes within white adipose tissue, suggesting enhanced 'browning' of the white adipose tissue.


CONCLUSIONS
Our data show that G0s2 is a physiological regulator of adiposity and energy metabolism and is a potential target in the treatment of obesity and insulin resistance.
Goodman Cancer Research Centre, McGill University, Room 616, 1160 Ave des Pins, Montréal, QC, H3A 1A3, Canada.
Wissal
W
El-Assaad
Karim
K
El-Kouhen
Amro H
AH
Mohammad
Jieyi
J
Yang
Masahiro
M
Morita
Isabelle
I
Gamache
Orval
O
Mamer
Daina
D
Avizonis
Nicole
N
Hermance
Sander
S
Kersten
Michel L
ML
Tremblay
Michelle A
MA
Kelliher
Jose G
JG
Teodoro
D052437:Adipocytes, Brown / Q000502:physiology*; D052436:Adipose Tissue, White / Q000502:physiology*; D050154:Adiposity / Q000235:genetics; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics*; D054338:Cell Transdifferentiation / Q000235:genetics*; D059305:Diet, High-Fat / Q000009:adverse effects; D004734:Energy Metabolism / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D007333:Insulin Resistance / Q000235:genetics*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D022722:Thermogenesis / Q000235:genetics; D015430:Weight Gain / Q000235:genetics*
D018797:Cell Cycle Proteins; C508072:G0S2 protein, mouse