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. 2006 Dec 29;351(4):860-4.
doi: 10.1016/j.bbrc.2006.10.129. Epub 2006 Nov 2.

AgRP-deficiency could lead to increased lifespan

Stephen M Redmann Jr  1 , George Argyropoulos
Affiliations

AgRP-deficiency could lead to increased lifespan

Stephen M Redmann Jr et al. Biochem Biophys Res Commun. .

Abstract

The Agouti-related protein (AgRP) is a central orexigenic peptide leading to increased food intake when ubiquitously overexpressed. AgRP-deficient (AgRP(-/-)) mice have either no phenotype or present an age-related leanness. In this study, AgRP(-/-) mice were fed alternate high fat or low fat diets in an effort to determine whether AgRP is a mediating factor for the effects of dietary fat on metabolic parameters. There were no striking metabolic differences between AgRP(-/-) and the equally obese wild type littermates but AgRP(-/-) mice displayed a significantly longer lifespan. The point estimate of median survival for the AgRP(-/-) group was 9.8% greater while the significantly low hazard ratio (0.494) suggests that mortality incidence of AgRP(-/-) mice is less than one-half that of the wild type reference population. It is concluded that although AgRP(-/-) mice become morbidly obese consuming a high fat diet (a landmark feature for a shortened lifespan), they seem to overcome obesity- and age-related pathologies and live significantly longer than their metabolically similar wild type littermates.

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Figures

Figure 1
Figure 1
Metabolic characteristics of AgRP-deficient (−/−) and wild type littermate (+/+) male mice: (A) Body weight, (B) Percent body fat, (C) Percent muscle mass, (D) Energy expenditure, (E) Food intake.
Figure 2
Figure 2
Metabolic characteristics of AgRP-deficient (−/−) and wild type littermate (+/+) female mice: (A) Body weight, (B) Percent body fat, (C) Percent muscle mass, (D) Energy expenditure, (E) Food intake.
Figure 3
Figure 3
Survival function estimates of AgRP-deficient (−/−) and wild type (+/+) littermate mice (males and females pooled together per genotype) (the asterisk “*” represents one censured observation corresponding to a surviving AgRP−/− male.
See this image and copyright information in PMC

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