Prenatal developmental events can influence adult phenotype and the risk of adult disease. However, it is unknown whether (or to what extent) the actions of hormones and nutrients on early postnatal growth can influence mammalian aging, adult health and longevity. We have recently shown that: (i) the remarkable extension of longevity in hypopituitary Ames dwarf mice can be completely reversed by a six-week course of growth hormone (GH) injections started at the age of 2 weeks;and (ii) limiting nutrient availability during the first three weeks of postnatal life by increasing the numbers of pups in a litter increases both median and maximal lifespan in genetically normal mice. Based on these novel and largely unexpected findings, we hypothesize that the period of rapid postnatal growth represents a critical time window for development of lifelong metabolic and other phenotypic characteristics that influence-and likely predict-longevity and functionality during old age. To test the validity of this hypothesis, we will examine the impact of modestly reducing the amount of available nutrients during suckling (or suckling and the immediate post-weaning period) in normal mice, and the effects of early (starting at one or two weeks) as compared to late (starting at eight weeks) GH replacement therapy in Ames dwarfs and in GHRH-/- mice with isolated GH deficiency. Endpoints will include both longevity and a series of age-sensitive traits related to health span, including indices of immune function, locomotion, stress resistance, and cataract development. We will pay special attention to endpoints related to fuel metabolism, with tests of somatotropic and insulin signaling, pancreatic beta cell function, metabolic rate and respiratory quotient, and expression of GH and insulin-related genes in the liver, skeletal muscle, and both subcutaneous and intra-abdominal (visceral) fat. Lastly, we will in parallel studies see whether early life nutrient limitation, before or before and after weaning, will benefit GHRKO (Laron dwarf) mice, which unlike Ames dwarf mice fail to benefit from calorie restriction (CR) when CR is started at the age of 2 months. Results of the proposed studies will be used to accept or reject specific hypotheses concerning mechanisms by which early hormonal or nutritional interventions can influence aging and longevity. In sum, we will take our studies of the interactions of longevity genes and CR in a novel direction to address the impact of transient changes in nutritional and hormonal signals during early postnatal life on mammalian aging, health span and longevity. Results of these studies will address critical gaps in the present understanding of developmental influences on aging and set a stage for addressing the relationships between early nutrition, growth and adult health which are of major public health significance.
Using normal and mutant mice, we have recently obtained novel and largely unexpected evidence that a modest reduction of nutrient availability during early postnatal development can produce significant extension of longevity, and that absence of growth hormone signaling during this brief period may be sufficient to produce a dramatic increase in life expectancy. In the proposed work we will identify mechanisms of these novel effects and determine whether the observed life extension is associated with positive impacts on health span. These studies address several issues of major public health significance including detrimental effects of early over nutrition and an exciting possibility that aging might be postponed and lifespan extended by judicious life style and diet modifications in children and adolescents.
|Xu, Ming; Tchkonia, Tamar; Kirkland, James L (2016) Perspective: Targeting the JAK/STAT pathway to fight age-related dysfunction. Pharmacol Res 111:152-4|
|Bartke, A; Sun, L; Fang, Y et al. (2016) Growth hormone actions during development influence adult phenotype and longevity. Exp Gerontol 86:22-27|
|Saccon, Tatiana D; Moreira, Fabiana; Cruz, Luis A et al. (2016) Ovarian aging and the activation of the primordial follicle reserve in the long-lived Ames dwarf and the short-lived bGH transgenic mice. Mol Cell Endocrinol :|
|Hascup, Kevin N; Lynn, Mary K; Fitzgerald, Patrick J et al. (2016) Enhanced Cognition and Hypoglutamatergic Signaling in a Growth Hormone Receptor Knockout Mouse Model of Successful Aging. J Gerontol A Biol Sci Med Sci :|
|Bartke, Andrzej; List, Edward O; Kopchick, John J (2016) The somatotropic axis and aging: Benefits of endocrine defects. Growth Horm IGF Res 27:41-5|
|Bartke, Andrzej (2016) Healthspan and longevity can be extended by suppression of growth hormone signaling. Mamm Genome 27:289-99|
|Wang, Bo; Merillat, Sean A; Vincent, Michael et al. (2016) Loss of the Ubiquitin-conjugating Enzyme UBE2W Results in Susceptibility to Early Postnatal Lethality and Defects in Skin, Immune, and Male Reproductive Systems. J Biol Chem 291:3030-42|
|Hascup, Erin R; Wang, Feiya; Kopchick, John J et al. (2016) Inflammatory and Glutamatergic Homeostasis Are Involved in Successful Aging. J Gerontol A Biol Sci Med Sci 71:281-9|
|Martinez, Carolina S; Piazza, VerÃ³nica G; GonzÃ¡lez, Lorena et al. (2016) Mitogenic signaling pathways in the liver of growth hormone (GH)-overexpressing mice during the growth period. Cell Cycle 15:748-59|
|Richardson, Arlan; Fischer, Kathleen E; Speakman, John R et al. (2016) Measures of Healthspan as Indices of Aging in Mice-A Recommendation. J Gerontol A Biol Sci Med Sci 71:427-30|
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