| RRC ID |
67924
|
| Author |
Kizaki T, Maegawa T, Sakurai T, Ogasawara JE, Ookawara T, Oh-ishi S, Izawa T, Haga S, Ohno H.
|
| Title |
Voluntary exercise attenuates obesity-associated inflammation through ghrelin expressed in macrophages.
|
| Journal |
Biochem Biophys Res Commun
|
| Abstract |
Chronic low-level inflammation is associated with obesity and a sedentary lifestyle, causing metabolic disturbances such as insulin resistance. Exercise training has been shown to decrease chronic low-level systemic inflammation in high-fat diet (HFD)-induced obesity. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Ghrelin is a peptide hormone predominantly produced in the stomach that stimulates appetite and induces growth hormone release. In addition to these well-known functions, recent studies suggest that ghrelin localizes to immune cells and exerts an anti-inflammatory effect. The purpose of the current study was to investigate the role of ghrelin expressed in macrophages in the anti-inflammatory effects of voluntary exercise training. Expression of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein (MCP)-1 and F4/80 was increased in adipose tissue from mice fed a HFD (HFD mice) compared with mice fed a standard diet (SD mice), whereas the expression of these inflammatory cytokines was markedly decreased in mice performing voluntary wheel running during the feeding of a HFD (HFEx mice). The expression of TNF-α was also increased in peritoneal macrophages by a HFD and exercise training inhibited the increase of TNF-α expression. Interestingly, expression of ghrelin in peritoneal macrophages was decreased by a HFD and recovered by exercise training. Suppression of ghrelin expression by siRNA increased TNF-α expression and LPS-stimulated NF-κB activation in RAW264 cells, which is a macrophage cell line. TNF-α expression by stimulation with LPS was significantly suppressed in RAW264 cells cultured in the presence of ghrelin. These results suggest that ghrelin exerts potent anti-inflammatory effects in macrophages and functions as a mediator of the beneficial effects of exercise training.
|
| Volume |
413(3)
|
| Pages |
454-9
|
| Published |
2011-9-30
|
| DOI |
10.1016/j.bbrc.2011.08.117
|
| PII |
S0006-291X(11)01535-X
|
| PMID |
21907183
|
| MeSH |
Adipose Tissue / metabolism
Animals
Cell Line
Chemokine CCL2 / metabolism
Ghrelin / biosynthesis
Ghrelin / physiology*
Inflammation / therapy*
Macrophages, Peritoneal / metabolism*
Male
Mice
Mice, Inbred C57BL
Obesity / therapy*
Physical Conditioning, Animal*
Tumor Necrosis Factor-alpha / metabolism
|
| IF |
2.985
|
| Resource |
| Human and Animal Cells |
RAW 264(RCB0535) |
