Friday, September 22, 2023
9/22/2023
We propose to develop as sustainable aging research infrastructure, a new and unique genetically heterogeneous laboratory rat model that can be used to evaluate putative life- and health-extending interventions. The rat has numerous advantages over the mouse for interventional aging research including more human-like physiology and pathophysiology, more cognitive sophistication, and greater genetic diversity compared with standard mouse strains. Inspired by the UM-HET3 mice used by the Interventions testing program, our rat model (OKC-HETb/w) will also be populations of genetically heterogeneous F2 descendants of 4 divergent, inbred strains. A significant difference from the UM-HET3 mice, our breeding scheme takes advantage of the rat’s substantial mitochondrial genomic diversity compared with the mouse to create a population half of which carries the BN strain mitochondria (OKC-HETb), the other half carries the WKY strain mitochondria (OKC- HETw). These mitochondrial genomes mimic great human mitochondrial diversity in that they differ at 95 nucleotides involving 11 of 13 mitochondrial protein-coding genes, 5 tRNA’s and both ribosomal subunits. Our preliminary data show that the OKC-HETb and OKC-HETw rats respond differently to exercise endurance, grip strength, and responsiveness to 17a-estradiol. As a proof of principle, we will evaluate in the OKC-HETb/w rat an anti-aging intervention (17a-estradiol) that was previously found to enhance the longevity of male mice only. An intriguing outcome of our project will be to verify whether or not, this sex-specificity is also seen in our rat model. In the R21 phase of this project we will produce the OKC-HETb/w rats and (1) characterize energetics-based health assays at whole animal and cellular levels under standard and stressed (HFD) conditions in both sexes in both mitochondrial genotypes, (2) determine the dose of 17a-estradiol that will yield blood levels comparable to those found at effective life-extending doses in the ITP study and the short-term effects of 17a-estradiol on metabolic parameters in diet-induced obese mice of both sexes, and (3) provide investigators with tissues as well as young and old OKC-HETb/w. In the R33 phase, we will use the information gained in the R21 phase to: (1) determine the effect of 17a-estradiol on the longevity and age-related pathology in both sexes and both mitochondrial genotypes and (2) determine the long-term effects of 17a-estradiol on age-related changes in metabolic and health parameters, again, in both sexes and both mitochondrial genotypes.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).
