This project will use the regenerating caudal fin of the zebrafish as a model system to test the hypothesis that the loss of regenerative capacity in senescence is caused by genomic instability. The significance of this stems from the fact that although this hypothesis has been popular for many decades, it remains controversial and has not been definitively tested. It is important to do so, because if the hypothesis is correct then health decline with age cannot be prevented, only slowed down. The hypothesis is testable because it makes specific predictions in regard to the effects of age, as well as of conditions that are known to either accelerate or decelerate aging. The first prediction is that loss of regenerative capacity with age is proportional to the loss of genomic integrity. The second prediction is that conditions that accelerate aging will increase genomic instability whereas conditions that extend lifespan will have the opposite effect. The third prediction is that genetic networks that function to promote regeneration early in life will tend to lose functionality and/or reliability later in life. These predictions, and hence our hypothesis, will be tested by way of two specific aims that make innovative use of zebrafish as an experimentally tractiable animal model for regeneration research, and high throughput sequencing to analyze genome-wide gene expression.
The first aim i s to determine how age, chronically elevated stress signaling (via Cortisol), and treatment with the lifespan-extending drug rapamycin affect regenerative capacity, genomic integrity, and mitochondrial function. Toward that end we will perform quantitative PCR of DNA extracted from caudal fins of young, middle aged, or old zebrafish that are either untreated or subjected to long-term treatments with Cortisol or rapamycin, and measure the change in relative amounts of DNA damage in both mitochondrial and nuclear genomes with respect to age and treatment. In addition, the rate and extent of tailfin regeneration will be quantified in each treatment group, and mitochondrial function assessed in tissue samples from each group. The second specific aim is to determine how age, chronically elevated Cortisol, and rapamycin treatment affect regenerative gene expression. Toward that end we will perform high-throughput sequence analyses of RNA (mRNA-seq and microRNA-seq) extracted from regenerating caudal fins dissected from young, middle aged, or old zebrafish that are either untreated or have been subjected to long-term treatment with Cortisol or rapamycin. These studies will both test our hypothesis, and provide the initial data required to systematically map the genomic regulatory systems underlying the decline of regenerative capacity in senescence.

Public Health Relevance

Old age is a major public health issue in the United States owing to the rapid expansion of the aging population. Health decline in old age entails progressive loss of functionality in the body's ability to repair and/or replace damaged tissues. In order to elucidate the causes of this decline, this project makes use of the regenerating tail fin of the zebrafish as an experimental model to ascertain whether age-related loss of regenerative capacity is caused by genomic instability, and whether this is exacerbated by chronic stress.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Exploratory Grants (P20)
Project #
5P20GM104318-02
Application #
8728964
Study Section
Special Emphasis Panel (ZGM1-TWD-B)
Project Start
Project End
Budget Start
2014-06-01
Budget End
2015-05-31
Support Year
2
Fiscal Year
2014
Total Cost
$388,079
Indirect Cost
$163,756
Name
Mount Desert Island Biological Lab
Department
Type
DUNS #
077470003
City
Salsbury Cove
State
ME
Country
United States
Zip Code
04672
Wu, Cheng-Wei; Deonarine, Andrew; Przybysz, Aaron et al. (2016) The Skp1 Homologs SKR-1/2 Are Required for the Caenorhabditis elegans SKN-1 Antioxidant/Detoxification Response Independently of p38 MAPK. PLoS Genet 12:e1006361
Soundararajan, Ramani; Stearns, Timothy M; Czachor, Alexander et al. (2016) Global gene profiling of aging lungs in Atp8b1 mutant mice. Aging (Albany NY) 8:2232-2252
Lisse, Thomas S; Middleton, Leah J; Pellegrini, Adriana D et al. (2016) Paclitaxel-induced epithelial damage and ectopic MMP-13 expression promotes neurotoxicity in zebrafish. Proc Natl Acad Sci U S A 113:E2189-98
Rizzo, Francesca; Coffman, James A; Arnone, Maria Ina (2016) An Elk transcription factor is required for Runx-dependent survival signaling in the sea urchin embryo. Dev Biol 416:173-86
King, Benjamin L; Yin, Viravuth P (2016) A Conserved MicroRNA Regulatory Circuit Is Differentially Controlled during Limb/Appendage Regeneration. PLoS One 11:e0157106
Davis, Allan Peter; Grondin, Cynthia J; Johnson, Robin J et al. (2016) The Comparative Toxicogenomics Database: update 2017. Nucleic Acids Res :
King, Benjamin L; Shi, Ling Fang; Kao, Peter et al. (2016) Calcium activated K⁺ channels in the electroreceptor of the skate confirmed by cloning. Details of subunits and splicing. Gene 578:63-73
Grondin, Cynthia J; Davis, Allan Peter; Wiegers, Thomas C et al. (2016) Advancing Exposure Science through Chemical Data Curation and Integration in the Comparative Toxicogenomics Database. Environ Health Perspect 124:1592-1599
Yamada, Toshiki; Krzeminski, Mickael; Bozoky, Zoltan et al. (2016) Role of CBS and Bateman Domains in Phosphorylation-Dependent Regulation of a CLC Anion Channel. Biophys J 111:1876-1886
Hartig, Ellen I; Zhu, Shusen; King, Benjamin L et al. (2016) Cortisol-treated zebrafish embryos develop into pro-inflammatory adults with aberrant immune gene regulation. Biol Open 5:1134-41

Showing the most recent 10 out of 36 publications