IGF-1 has sexually dimorphic, pleiotropic, and time-dependent effects on healthspan, pathology, and lifespan

• DOI: 10.1007/s11357-017-9971-0
• Publication Date: 2017-04-13T04:08:03Z
• Authors: Nicole M. Ashpole; Sreemathi Logan; Andriy Yabluchanskiy; Matthew C. Mitsch...; Han Yan; Julie A. Farley; Erik L. Hodges; Zoltan Ungvari; Anna Csiszar; Sixia Chen; Constantin Georgescu; Gene B. Hubbard; Yuji Ikeno; William E. Sonntag
• Keywords: Male; 0301 basic medicine; Sex Characteristics; 0303 health sciences; Health Status; Longevity; Genetic Pleiotropy; 3. Good health; Mice, Inbred C57BL; Mice; 03 medical and health sciences; Animals; Female; Insulin-Like Growth Factor I

Reduced circulating levels of IGF-1 have been proposed as a conserved anti-aging mechanism that contributes to increased lifespan in diverse experimental models. However, IGF-1 has also been shown to be essential for normal development and the maintenance of tissue function late into the lifespan. These disparate findings suggest that IGF-1 may be a pleiotropic modulator of health and aging, as reductions in IGF-1 may be beneficial for one aspect of aging, but detrimental for another. We postulated that the effects of IGF-1 on tissue health and function in advanced age are dependent on the tissue, the sex of the animal, and the age at which IGF-1 is manipulated. In this study, we examined how alterations in IGF-1 levels at multiple stages of development and aging influence overall lifespan, healthspan, and pathology. Specifically, we investigated the effects of perinatal, post-pubertal, and late-adult onset IGF-1 deficiency using genetic and viral approaches in both male and female igf f/f C57Bl/6 mice. Our results support the concept that IGF-1 levels early during lifespan establish the conditions necessary for subsequent healthspan and pathological changes that contribute to aging. Nevertheless, these changes are specific for each sex and tissue. Importantly, late-life IGF-1 deficiency (a time point relevant for human studies) reduces cancer risk but does not increase lifespan. Overall, our results indicate that the levels of IGF-1 during development influence late-life pathology, suggesting that IGF-1 is a developmental driver of healthspan, pathology, and lifespan.