Hypothalamic fatty acid metabolism mediates the orexigenic action of ghrelin.
نویسندگان
چکیده
Current evidence suggests that hypothalamic fatty acid metabolism may play a role in regulating food intake; however, confirmation that it is a physiologically relevant regulatory system of feeding is still incomplete. Here, we use pharmacological and genetic approaches to demonstrate that the physiological orexigenic response to ghrelin involves specific inhibition of fatty acid biosynthesis induced by AMP-activated protein kinase (AMPK) resulting in decreased hypothalamic levels of malonyl-CoA and increased carnitine palmitoyltransferase 1 (CPT1) activity. In addition, we also demonstrate that fasting downregulates fatty acid synthase (FAS) in a region-specific manner and that this effect is mediated by an AMPK and ghrelin-dependent mechanisms. Thus, decreasing AMPK activity in the ventromedial nucleus of the hypothalamus (VMH) is sufficient to inhibit ghrelin's effects on FAS expression and feeding. Overall, our results indicate that modulation of hypothalamic fatty acid metabolism specifically in the VMH in response to ghrelin is a physiological mechanism that controls feeding.
منابع مشابه
Hypothalamic Ceramide Levels Regulated by CPT1C Mediate the Orexigenic Effect of Ghrelin
Recent data suggest that ghrelin exerts its orexigenic action through regulation of hypothalamic AMP-activated protein kinase pathway, leading to a decline in malonyl-CoA levels and desinhibition of carnitine palmitoyltransferase 1A (CPT1A), which increases mitochondrial fatty acid oxidation and ultimately enhances the expression of the orexigenic neuropeptides agouti-related protein (AgRP) and...
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ورودعنوان ژورنال:
- Cell metabolism
دوره 7 5 شماره
صفحات -
تاریخ انتشار 2008