Growth Hormone Guidance

Intact growth hormone signaling pathways are needed for methionine restriction to extend mouse lifespan.

Jenny Rood
Feb 28, 2015

OLD MICE: Ames dwarf mice (above, right) outlive wild-type mice (above, left), but their life span is unresponsive to changes in dietary methionine levels.CHUCK KIMMERLE AT UNIVERSITY OF NORTH DAKOTA

EDITOR'S CHOICE IN MOLECULAR BIOLOGY

The Paper
H.M. Brown-Borg et al., “Growth hormone signaling is necessary for lifespan extension by dietary methionine,” Aging Cell, 13:1019-27, 2014.

The paradox
Genetic defects in growth-hormone (GH) signaling extend life span in mice, as do diets minimizing the intake of a single amino acid, methionine. Yet scientists had previously observed that the Ames dwarf mouse, deficient in GH, lives longer but has upregulated methionine metabolism. Holly Brown-Borg of the University of North Dakota and her colleagues thus decided to examine how GH genetics and dietary methionine might interact to impact life span.

The diet
Brown-Borg’s team compared four groups of mice on three different diets. Ames dwarf mice, GH-receptor knockout mice, transgenic...