Efeitos de acidos graxos na indução de inflamação hipotalamica / Effects of fatty acids on the induction of hypothalamic inflammation

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

In animal models of diet-induced obesity, the activation of an inflammatory response in the hypothalamus produces molecular and functional resistance to the anorexigenic hormones insulin and leptin. The primary events triggered by dietary fats that ultimately lead to hypothalamic cytokine expression and inflammatory signaling are unknown. Here, we test the hypothesis that dietary fats act through the activation of Toll-like receptors 2/4 and endoplasmic reticulum stress to induce cytokine expression in the hypothalamus of rodents. Rats were treated icv with different types of fatty acids and hypothalamic protein extracts were obtained for determination of inflammatory and endoplasmic reticulum stress protein expression by immunoblot. Localization of inflammatory markers were performed by immunohistochemistry. Long-chain saturated fatty acids activate predominantly Toll-like receptor 4 signaling, which determines not only the induction of local cytokine expression but also promotes endoplasmic reticulum stress. Rats fed on a monounsaturated fat-rich diet do not develop hypothalamic leptin resistance, while Toll-like receptor 4 loss-of-function mutation and immunopharmacological inhibition of Toll-like receptor 4 protects mice from diet induced obesity. Toll-like receptor 4 acts as a predominant molecular target for saturated fatty acids in the hypothalamus, triggering the intracellular signaling network that induces an inflammatory response and determines the resistance to anorexigenic signals.

ASSUNTO(S)

acidos graxos obesity toll-like receptors receptores tool-like fatty acids obesidade

ACESSO AO ARTIGO

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