TITLE:
Effects of oleic acid on murine macrophage dysfunction
AUTHORS:
Naofumi Shiomi, Keiko Watanabe
KEYWORDS:
Macrophage; Oleic Acid; Cancer; Allergy; Dysfunction
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.6 No.6,
June
26,
2013
ABSTRACT:
Obese
individuals exhibit much higher risks not only for metabolic syndrome, but also
for cancer and allergies, than normal-weight subjects. This fact suggests that
signals secreted from adipocytes change the characteristics of lymphocytes,
such as macrophages and T-cells. We focused on a free fatty acid, oleic acid,
as a signal inducing such changes and examined its effects on murine J774.2
macrophages. When the cells were cultured in medium containing high concentrations
(1, 2 and 4 mM) of oleic acid, apoptosis occurred, and the apoptotic cells were
gathered into clusters of very large size by the work of enzymes for phagocytosis.
When the cells were cultured in medium containing 0.5 mM of oleic acid, the
fatty acid did not affect cell growth; however, it inhibited nitrogen monoxide
(NO) secretion and the gene expressions of interleukins and TNF-α. NO disturbs the invasion of
macrophages into blood vessels, and interleukins promote the differentiation
and proliferation of T- and B-cells. Therefore, these results suggest that the
high risks for cancer and allergies observed in obese subjects are associated with the dysfunction of macrophages induced by fatty acids. Moreover, we also examined the protective effects of
carnitine against dysfunction. However, carnitine did not exhibit sufficient
effects.