Chemical Genetics to Define Regenerative Pathways

Oregon State University, Corvallis OR

Investigators

Abstract

Abstract: Injury, disease and aging all result in a loss of tissue and reduced quality of life. Numerous human conditions could be significantly improved if therapies that encourage tissue regeneration were available. Zebrafish, unlike mammals, have the remarkable ability to fully regenerate lost or damaged tissues. This regenerative ability has stimulated scientific investigations for decades with hopes of finding ways to permit human tissue regeneration. A number of experimental models have been developed to identify the genes that control the regeneration process. The consensus from these studies is that the basic regeneration pathways are well-conserved, yet we are just beginning to identify the networks that permit tissue regeneration. There remain enormous information gaps. The focus of this proposal is on defining the signaling pathways and the genes required for regeneration. In preliminary studies, two zebrafish fin regeneration models were developed and a number of regeneration-responsive genes were identified using microarray analysis. An immediate goal is to determine the role of these genes in the regeneration process. In addition, this proposal will, for the first time use the power of chemical genetics to probe tissue regeneration. The main goal is to identify chemicals that perturb normal regeneration. The hypothesis is that if a chemical specifically block tissue regeneration, it must interfere or block the activity of critical macromolecules that are essential for this remarkable process. As part of the preliminary data for this proposal, a commercially available chemical library was screened and a number of small molecules were identified that specifically inhibited tissue regeneration. The goal of this proposal is to define the molecular and cellular mechanisms of early life stage fin regeneration in zebrafish. The underlying hypothesis is that there are common regenerative pathways that are induced in regenerating tissues. A natural extension of this hypothesis is that once critical genes and pathways are identified in zebrafish; they can be validated in other regenerative models. Two specific aims have been developed to identify novel regulators of early life stage fin regeneration 1) Identify and define the role of genes expressed during fin regeneration; 2) To identify bioactives that modulate early life stage regeneration, and begin to define their biochemical targets Together these studies will begin to define the molecular machinery that controls regeneration. The broader impacts for this project are many. In addition to identifying genes and pathways that choreograph tissue regeneration, these studies will generate a number of molecular markers that can be evaluated in other regenerative models such as mammals. It would be impractical to conduct a chemical genetic screen in mammals, so rodent cannot be used for drug discovery. The results these zebrafish discovery studies are rapid and can be rapidly translated to other models. On a broader scale, the analysis the structure and function relationships of the chemicals may lead to novel drug development that may be used to promote tissue regeneration in humans. There would be a tremendous clinical benefit if therapies that encourage tissue regeneration following injury were available. Successful completion of these studies will also highlight the enormous advantages of chemical genetic approaches compared to traditional gene knockout or chemical induced-genetic screens to study complex processes. From a training standpoint, a number of undergraduate, graduate and high school students will be involved with the proposed studies. Regardless of their stage in career development, each will gain valuable experience in hypothesis formulation, experimental design, laboratory organization, and data presentation. The Tanguay laboratory is committed to K-12 education and outreach as demonstrated a long track record in involving teachers and students in research. Thus, it is expected that research from this project will provide numerous opportunities to make significant scientific discoveries, but as importantly, a mechanism to train students and to translate the results to the general public.