Advancing age is the major risk factor for many serious illnesses, including cancer, cardiovascular disease, and dementia. The rising number of older individuals is thus causing a major burden of ill health. However, individuals that reach an exceptional old age often seem to escape or delay age-related diseases, and part of this trait seems to be encoded in their genome. Hence, by studying the genome of long-lived individuals, we may be able to identify mechanisms that could be harnessed to foster healthy ageing in the general population. Our previous work suggests that large genome-wide association studies (GWAS) of long-lived individuals can be used to identify genetic variants involved in longevity. However, the common genetic variants thus far identified using GWAS only explain a minor part of the genetic component of longevity. This trait, therefore, may well be mainly determined by rare genetic variants, which can be detected using whole-genome or exome sequencing of long-lived families or exceptionally long-lived individuals. The aim of the proposed project is to establish the effect of genetic variants identified in genetic studies of long-lived individuals on general health and lifespan using cellular models and, subsequently, model organisms. To this end, we use CRISPR/Cas9 genome editing to generate cell lines and mice that harbour genetic variants identified in GWAS and sequencing studies of long-lived families and exceptionally long-lived individuals. Our initial focus is on rare genetic variants in genes involved in the insulin/insulin-like growth factor 1 (IIS)/mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signalling pathways, given the well-known role of these pathways in ageing in pre-clinical model organisms. We subsequently perform detailed characterisation of the generated cell lines, where we look at the effect of the variants on IIS/mTOR and MAPK/ERK signalling as well as general cellular health. In the generated mouse lines we study effects on lifespan and general health. The phenotypic characterisation is performed at three stages during the life of the mice, i.e. young, middle, and old age and we also collect tissues of the mice for molecular analyses at the same timepoints. In addition, we aim to design a high-throughput screening platform to identify compounds that can pharmacologically recapitulate the effects we observed in our generated cell lines.
