Iain A. Drummond - US grants

DESCRIPTION (provided by applicant): The cilium has emerged as a critical cellular organelle in the pathology of kidney cystic disease, retin degeneration, hydrocephalus, and left-right asymmetry defects. Now that a large number of proteins have been identified as part of the "cilia proteome", we propose as the central hypothesis of this application that a significant number of human disease genes will be linked to novel genes that are currently represented in the cilia proteome but are yet uncharacterized. We have exploited the zebrafish to identify novel genes involved in cilia formation and to determine the physiological roles of cilia in kidney, brain, and the generation of left- right asymmetry. Zebrafish are particularly well-suited for high-throughput analysis of the cilia proteome because 1) cilia function can be studied in living embryos in multiple organ systems, 2) both sensory and motile cilia can be studied, 3) phenotypes related to cilia defects have been well characterized, and 4) forward and reverse genetic approaches to gene function are well established. In Aim 1 we plan to address the lack of useful phenotyping tools for high-throughput analysis of the cilia;proteome by generating new epitope-tagged cilia protein-expressing transgenic lines of zebrafish to image cilia, basal bodies and the localization of IFT proteins in living embryos. We will also make transgenics that report that activity of sensory cilia (calcium indicator transgenics). Proteomic and genomic approaches have identified hundreds of proteins associated with cilia and each o these is a candidate human disease gene. In Aim 2 we will conduct a systematic analysis of cilia proteome genes that are highly conserved but completely uncharacterized. Zebrafish homologs of novel cilia genes will be targeted with antisense morpholino oligos and morphant embryos subjected to a battery of assays including live imaging, confocal immunofluorescence of cilia and basal body markers, and cilia sensory signaling. In Aim 3 we will positionally clone the schmalhans gene, a novel gene associated with cilia motility and a candidate gene for human primary ciliary dyskinesia. The overall goal of these studies is to 1) identify novel ciliogenic genes 2) generate new tools to study cilia formation and 3) categorize the large number of cilia associated proteins in terms of their function(s).

kidney; histogenesis; pathologic process; gene mutation; polycystic kidney; cell proliferation; cellular polarity; disease /disorder model; molecular pathology; gene expression; vertebrate embryology; cell transplantation; molecular cloning; zebrafish; nucleic acid sequence;

Autosomal dominant polycystic kidney disease is caused primarily by mutations in two genes, Pkd1 and Pkd2, which function together as a calcium channel complex. Subcellular localization studies suggest that the polycystin2 protein may act in the apical cell membrane associated with cilia or in internal cell membranes as a calcium release channel. However, it is currently not known where polycystin2 channel activity acts in epithelia or which cellular signaling systems may impinge on polycystin2 function. Disruption of zebrafish polycystin2 gene expression using antisense morpholino oligos results in rapid kidney cyst development, randomized organ laterality, hydrocephalus, and body axis curvature. These defects are rescued by co-injection of the human pkd2 mRNA. In Aim 1. we propose using the zebrafish as an in vivo system for structure function analysis of polycystin2. We hypothesize that specific amino acid motifs in polycystin2 target it to its cellular site of action. By disrupting these either in the endogenous zebrafish polycystin2 or in rescuing human polycystin2 mRNAs we will test whether subcellular localization affects the cellular function of polycystin2. In Aim 2. we hypothesize that polycystin 2, acting as a calcium channel, mediates the effects of physical forces on the epithelium. We will measure calcium responses in isolated kidney tubules that lack polycystin2 function or that express altered pkd2 alleles. Finally we propose that mutations in polycytin2 interacting proteins or downstream mediators may effect signaling or function of polycystin2. In Aim 3. we outline a plan to identify cellular components that interact with polycystin2 by screening for dominant suppressors of the zebrafish polycystin2 phenotype. This proposal exploits unique advantages of the zebrafish as a model organism to more fully explore the function of polycystin2 in vivo and further our understanding of the cellular mechanisms of autosomal dominant polycystic kidney disease.

[unreadable] DESCRIPTION (provided by applicant): Odd-skipped related 1 (osr1) is the earliest gene known to be expressed during the formation of the intermediate mesoderm (IM), the embryonic tissue which gives rise to all vertebrate kidney tissue. In zebrafish, chicken, and mouse embryos, osr1 is expressed in undifferentiated IM, and is down regulated upon initiation of kidney duct and tubule formation. Injection of morpholinos to osr1 in zebrafish leads to almost complete loss of early kidney markers, expansion of both dorsal and ventral markers, and a hyperconvergent extension phenotype similar to the Bmp2b mutant swirl. Mice with homozygous deletions in osr1 have severe defects in kidney formation. Misexpression of osr1 in chicken embryos results in ectopic expression of kidney genes in the somite. Finally, osr1 expression is lost in zebrafish swirl mutants. From these data, several, not mutually exclusive hypotheses regarding the function and regulation of osr1 during kidney formation can be postulated: (1) osr1 functions during early embryonic patterning to inhibit dorsal and ventral patterning and establish a band of tissue competent to form IM; (2) osr1 directly promotes early kidney gene expression; and (3) osr1 maintains kidney precursor cells in an early lineage compartment and inhibits terminal differentiation of epithelial structures. These hypothesis will be tested by conducting osr1 gain and loss of function experiments in zebrafish, chicken, and mouse embryos, by studying the effects of the misexpression of other kidney regulatory genes on osr1 expression, and by examining osr1 expression in zebrafish dorso-ventral patterning mutants. By studying osr1 in three diverse vertebrate embryos, a comprehensive picture should emerge of the roles of osr1 during kidney formation, which should add significantly to our understanding of the regulation of kidney development. The studies may also lead to increased understanding of congenital kidney anomalies and may yield important information that can be used to generate kidney tissue for therapeutic purposes. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): Mutations in Polycystin-1 (PKD1) and Polycystin-2 (PKD2) account for all cases of Autosomal Dominant Polycystic Kidney Disease (ADPKD), the most common heritable human disease. In addition to their localization and function in primary cilia, polycystins are localized at sites of cell-matrix interactions, indicating they may act there as mechanosensors of the cellular environment. We have modeled polycystic kidney disease in the zebrafish by disrupting the function of polycystin1 and polycystin2. Our results demonstrate that Polycystins function in signaling pathways that sense the compostion of extracellular matrix and generate feedback signals that terminate "fetal" programs of gene expression. These signals are likely to involve PI3K and intracellular calcium stores since PI3K or SERCA pump inhibitors can phenocopy polycystin loss of function. Specifically, our findings that developmental collagen expression persists abnormally in older larvae lacking polycystins is directly relevant to defects associated with extracellular matrix seen in a variety of ADPKD pathologies including cystic kidney disease, vascular aneurysm, abdominal wall hernia, pericardial effusion, and defects in chondrogenesis. In this proposal we plan to exploit our ability to generate compound loss of function as well as gain of function conditions in zebrafish embryos to dissect signaling pathways by which polycystins function as sensors of the cellular environment. We hypothesize that Polycystin1, functioning at sites of cell matrix contact, interacts with focal adhesion proteins to generate signals involving PI3K that downregulate collagen gene expression. We will test whether beta1 integrin, FAK, or ILK are required in this pathway. We will also test whether the C-terminal product of Polycystin1 GPS cleavage or other subdomains of polycystin1 are sufficient to rescue polycystin1 morphants. The role of ER calcium stores in signaling will be explored by measuring ER calcium in polycystin deficient embryos and assaying for genetic interactions of polycystin1 and polycystin2 with stim1 and orai1, the recently discovered store operated calcium channels. Although it has long been appreciated that defects in extracellular matrix were prominent in ADPKD pathology, a direct role for Polycystins as regulators of matrix production has yet to be demonstrated. If sucessful, our work will provide a direct link between Polycystins as signaling proteins and the control of extracellular matrix production that may be common to all ADPKD pathologies. PUBLIC HEALTH RELEVANCE: Polycystic kidney disease is a common life-threatening disorder for which there is no cure. We intend to show how mutations in Polycystic kidney disease genes result in structural defects in affected organs by causing misregulation of collagen gene expression. Understanding the cellular basis of this disease will create new opportunities to improve the lives of those that suffer from it.

DESCRIPTION (provided by applicant): Congenital abnormalities of the kidney are the major cause of pediatric kidney disease which encompass renal agenesis, juvenile cystic disease, nephrotic syndromes, and Wilms tumor. Understanding kidney development not only guides our understanding of congenital kidney disease but also provides a framework for developing interventions to restore kidney function. Many known disease genes are transcription factors and signaling molecules that regulate kidney organogenesis;in this proposal we aim to understand how regulatory and signaling molecules function to drive initial formation of the kidney and how they might be harnessed to promote kidney tubule regeneration. We have discovered that the odd- skipped related1 (osr1) gene is required to regulate the development of all nephron cell types in zebrafish and for nephrogenesis in mice. We propose extending our comparative analysis of osr1 function in zebrafish and mouse to characterize a distinct cell-autonomous role for osr1 in podocyte differentiation and a non-cell autonomous role for osr1 in tubule cell and angioblast differentiation. Mosaic analysis of osr1-deficient cells in zebrafish embryos, knockdown approaches in mouse kidney explant culture, and generation of a conditional Osr1 knockdout mouse will be used to further our understanding of conserved functions of osr1 in kidney cell differentiation and nephron patterning. Cell non-autonomous effects of osr1-deficiency in zebrafish appear to be due to altered wnt signaling. We will examine wnt signaling and the function of frizzled receptors in previously unexplored contexts including nephric duct formation, nephron patterning, and recovery from kidney injury. Insights gained from this work will guide future efforts to direct kidney progenitor cell differentiation and restore kidney tubule function after injury. PUBLIC HEALTH RELEVANCE: Birth defects associated with impaired kidney development are the primary cause of pediatric kidney disease and can have long lasting effects into adulthood. Chronic kidney disease that results is currently only treatable by kidney dialysis or transplant. We aim to better understand kidney birth defects and apply what we learn about gene regulation and cell signaling to new approaches to treating pediatric and adult kidney disease.

DESCRIPTION (provided by applicant): Ciliogenesis defects are central to kidney diseases including cystic kidney disease and nephronophthisis, two major causes of kidney failure in children and adults. The pathogenic mechanisms in ciliopathies remain puzzling however since cyst formation is delayed and highly focal in postnatal conditional PKD knockout models. It is now clear that renal injury significantly exacerbates cystic disease in the context of cilia defect, suggesting that ciliogenic responses may play a key role in tubule regeneration. Our finding that ciliogenic transcription factors FOXJ1 and rfx2 are rapidly induced by injury or mechanical stretch suggests a new paradigm for understanding cystic disease where ciliogenesis may be required for kidney tubule homeostasis and regeneration after injury. We also find that cell stretch is by itself sufficient to stimulate cell proliferation, further implicating mechanosensingin tubule repair. Our data together with the newly established role of purinergic signaling in kidney tubule mechanosensing suggests a strong link between cell stretch, purinergic signaling, proliferation and transcriptional activation of ciliogenesis. The central hypothesis of this proposl is that kidney tubules lacking the ability to stimulate or maintain ciliogenesis, due to cilia gene mutation, cannot undergo proper repair and are predisposed to cyst formation. This proposal aims to identify signaling pathways that control ciliogenesis in response to injury and stretch and directly link these pathways to transcriptional control of FOXJ1 and rfx2. We will also determine whether stretch induced ciliogenesis and cell proliferation are signaled by the same or divergent pathways. The transcriptional responses to stretch and the significance of foxj1 expression to tubule regeneration will also be examined in mouse models. If successful, this work would integrate tubule injury and mechanosensory signaling pathways with transcriptional control of ciliogenesis and reveal new elements of tubule homeostasis central to kidney disease.

PROJECT SUMMARY In this request for grant transfer, we aim to continue our work defining the signals and mechanisms that mediate connection of newly formed nephrons to the kidney collecting system. Defining mechanisms of tubule interconnection remains incompletely understood and will be essential for engrafting iPScell derived kidney organoids or other stem cell derived kidney replacement tissue. This grant period will be devoted to completing our study of receptors, ligands, and signal transduction pathways that mediate invasive cell behavior and tubule interconnection. Focusing on the regenerating kidney in adult zebrafish as a model of nephron addition, we will use a combination of loss of function mutants, fluorescent transgene reporters, and in situ markers of tissue invasion to define essential signals and effectors of tubule interconnection. The PI, Dr. Iain Drummond, has moved his lab to the Mount Desert Island Biological Laboratory to take on the position of Professor and Director of the Davis Center for Aging and Regeneration. The reasons for the transfer of institution are: 1) The MDI Biological Laboratory is a historical seat of fundamental kidney research, notably the site of Homer Smith's and Frank Epstein's insightful and seminal studies on kidney evolution and epithelial transport. 2) MDI Bio Lab has evolved to be an NIH Center of Research Excellence in Aging and Regeneration, focusing on fundemental studies using genetic model organisms which aligns with the Drummond lab's focus on zebrafish regeneration. Dr. Drummond assumed the position of PI on the MDIBL COBRE grant allowing him to continue and expand his role mentoring young investigators. 3) Under his directorship MDIBL has obtained new, cutting-edge microscopy equipment (Zeiss 980 two photon confocal microscope) that will enable new live imaging approaches to tubule interconnection studies and further developed single cell RNA seq capabilies that will allow completion of kidney regeneration studies. 4) MDIBL has committed support for the PI, students, and a Postdoc that will increase lab productivity and provide more long term stability. 5) Ongoing collaborations with the Jackson Lab on MDI will enable translation of fish studies to mouse models of kidney engraftment. The career plans of the PI are to continue to lead the field in zebrafish kidney development and regeneration and translate fundamental studies of developmental mechanisms and repair pathways to address human AKI and CKD.

PROJECT SUMMARY/ABSTRACT The major components of the Nephrology T32 program at the Massachusetts General Hospital (MGH) are integrated to offer comprehensive multidisciplinary research training to 4 highly selected postdoctoral trainees per year (each receiving a minimum of 2 years of support) under the supervision of 19 senior mentors with diverse and complementary research expertise. Our goal is to train the future leaders of Academic Nephrology. The program includes an exceptionally well-equipped research environment with state-of-the-art technologies. Our collaborative training program provides formal didactic instruction and enrichment activities critically important during the formative training years, and all research trainees complete a program in the Responsible Conduct of Research. Our program has a strong foundation in the Basic Sciences, and an emerging expertise in Clinical and Translational (C/T) Science. The 3 major components of our T32 Program are as follows: A. Training Organized by Established and Emerging Disciplines. The program has a continued focus in Basic (or Fundamental) Research and a growing expertise in C/T Research. Our highly selected and well- funded senior mentoring pool is strongly aligned in these two areas. We have also specifically added a concentration in the area of genetics and genomics of kidney disease, built around the new Associate Director, Iain Drummond PhD, with a total of 4 senior mentors in this area. B. Training Tailored to the Background of Trainees with the Number of Trainees Optimized. In this renewal, we request 4 postdoctoral positions (from our original 7) that will be offered on an annual basis to selected candidates with PhD, MD-PhD or MD degrees. In general, two will be allocated to trainees with a focus in basic research and two to trainees with a focus in C/T research. The profile of our diverse applicants over the past 5 years suggests we will have an excellent applicant pool to meet this balance. The duration of support will be individualized. We provide tuition support for formal instructional courses to trainees in a variety of areas including C/T Science, and in areas of Basic Science for MDs who are committed to a fundamental research track but have minimal wet bench experience. C. Training Facilities and Resources. Training is conducted in the laboratories of our Mentors, a collaborative group of established investigators with strong training records and achievements in kidney research. The MGH Division of Nephrology laboratories collectively occupy >20,000 sq ft of dedicated research space, with over 80% allocated to wet-bench space. Training in C/T Research includes access to the full range of acute and chronic care settings at MGH, including intensive care units, hemodialysis and transplant units and numerous outpatient clinics, and an infrastructure involving statisticians, research coordinators, technicians, and dedicated space to perform human studies.

ABSTRACT This Supplement proposal takes advantage of novel genetic model systems and bioinformatic approaches developed by two young investigators supported by the MDIBL COBRE P20 award (Comparative Biology of Tissue Repair, Regeneration and Aging; P20GM104318) and extends the impact of these approaches to solving the problems in Alzheimer?s disease (AD). Each of these studies proposes a pilot project that will allow the PI to seek competing support to pursue promising leads from the research proposed in this supplement request. COBRE Project 1 (Beck). Nuclei from AD neurons exhibit global mis-localization/degradation of nuclear lamin proteins and loss of heterochromatin marks both in human patients and animal models. Although these changes in chromatin architecture have been well characterized, the exact mechanism by which they contribute to degenerative changes in AD remains unknown. This proposal aims to determine how the disruption of nuclear chromatin architecture contributes to degenerative changes in AD. Our preliminary results demonstrate that, in normal young nuclei, only genes lacking CpG islands (CGI- genes) can reside within lamina-associated heterochromatin, when transcriptionally inactive. In this project, we will test the novel hypothesis that changes in chromatin architecture in AD cause mis-localization of CGI- genes that, in turn, triggers their uncontrolled expression in tissues/contexts where they should not be expressed. We will also examine whether CGI- gene mislocalization can be used as a diagnostic marker for AD in human clinical samples. COBRE Project 3 (Rollins). During AD, the association of Tau with the ribosome leads to its dysfunction. Such dysfunction is likely due to association of Tau with ribosomal protein 6 (RPS-6). This association coincides with the dephosphorylation of RPS-6, which is a potential mechanism by which Tau causes ribosome dysfunction and AD pathology. Using genetic models of RPS-6 phosphorylation we have generated in C.elegans, we will determine if phosphorylated RPS-6 reduces association of Tau with ribosomes. This will be accomplished by tracking the association of fluorescently tagged Tau with active ribosomes using fluorescent polysome profiling. Quantifying the association of Tau with the ribosome in RPS-6 mutants that cannot be phosphorylated or mimic constitutive phosphorylation will provide direct evidence that Tau association with the ribosome is controlled by RPS-6. Furthermore, measuring the lifespan and locomotion of the RPS-6 phospho-mutants in the presence of neuronally expressed Tau will determine whether phosphorylation of RPS-6 may alleviate symptoms of AD. Successful completion of these studies will show how nuclear structural changes leads to dysregulated gene expression in AD and support the development of new diagnostic markers of AD. This work will also clarify how Tau protein causes ribosome dysfunction in AD and support development of therapies targeting RPS-6 phosphorylation to slow the onset and progression Alzheimer?s disease.

OVERALL PROJECT SUMMARY Regeneration of damaged and lost tissues is limited in humans and other mammals. However, robust regeneration is the norm for numerous diverse invertebrates and lower vertebrates. COBRE Phase I, Comparative Biology of Tissue Repair, Regeneration and Aging, played a central role in establishing and growing the Kathryn W. Davis Center for Regenerative Biology and Medicine (Davis Center) at the MDI Biological Laboratory (MDIBL) and in dramatically improving the institution?s research environment. The Davis Center was founded on the guiding principle that studying diverse animal models would lead to a detailed and predictive understanding of the cellular and molecular mechanisms of tissue and organ regeneration, and an understanding of why these processes are poorly active in most human tissues and of why they decline with disease and aging. This in turn would lead to a rational foundation for development of regenerative medicine therapies, particularly small molecule drug candidates capable of stimulating tissue regeneration and slowing or reversing aging-induced degenerative changes in patients. COBRE Phase I supported four early-career Project Leaders and one mid-career Project Leader. All five Project Leaders graduated from Phase I with independent grant support. The average time for graduation of the four early-career Project Leaders was 2.8 years. Phase I Project Leaders also achieved multiple other successes including publication of significant peer-reviewed papers, creation of intellectual property, receipt of foundation and R21 grants and significant peer recognition. Other noteworthy successes include further development and patenting of MSI-1436, the only small molecule known to stimulate regeneration of the adult mammalian heart following a heart attack, discovery of two small molecules with potential to reverse chemotherapy-induced peripheral nerve damage, development of new disease models and research tools, and formation of a growing IDeA program/Maine state government partnership that allowed MDIBL to obtain $3M in voter-approved state bond funding to expand research infrastructure. COBRE Phase II will continue to support the growth and development of the Davis Center in order to establish a self-sustaining critical mass of investigators. Three new early-career scientists, Drs. Sam Beck, James Godwin and Jarod Rollins, have been recruited as Phase II Project Leaders. Recruitment of a fourth Davis Center faculty member is underway. Research programs of Phase II Project Leaders are highly synergistic with and bring new scientific expertise to the Davis Center. Essential services and resources will be provided to the Project Leaders and larger scientific community by continuation of the Comparative Functional Genomics Core and Comparative Animal Models Core. COBRE Phase II will greatly enhance the development of the Davis Center and MDIBL, which in turn will contribute to the continued enhancement of the biomedical research environment in Maine.

Project Summary Kidney disease is the 9th leading cause of death in the U.S. Because few therapies exist to prevent or slow progression, over 700,000 patients have End Stage Renal Disease. These patients are treated with dialysis or renal transplant, the latter resulting in markedly superior survival. However, kidney donors are limited and there is an important unmet need for strategies that enhance renal repair or generate new nephrons for renal replacement. Pluripotent stem cell derived organoids display key features of differentiated kidney tubules and glomerular structures in vitro, and we have shown that they generate patterned nephrons in vivo displaying kidney functions such as filtration and glucose uptake by the proximal tubule. To develop this technology for renal replacement, stem cell derived tubules must be connected to host tubules for urinary output. Our recent work in the zebrafish demonstrated that FGF signaling acts as a chemotactic signal to recruit and polarize cells at sites of new nephron formation and canonical Wnt signaling is required for invasive cell rearrangement to connect tubule lumens. Additional signaling pathways including non-canonical wnt signaling are also likely to play a role in tubule interconnection. To fully explore the requirements for tubule interconnection we have established a synergistic, three-part discovery platform comprising 1) genetic analysis of in vivo new nephron addition in the regenerating zebrafish adult kidney, 2) in vitro 3D cell culture analysis of mammalian epithelial fusion, and 3) in vivo stem cell-derived kidney organoid engraftment to a host mouse collecting system. We will combine these approaches to analyze multiple steps of the tubule fusion process involving 1) recruitment of nephron progenitor cells to target epithelia, 2) removal of intervening ECM/basement membranes, 3) patterned collective cell invasion of target epithelia, and 4) establishment of a continuous patent new lumen to convey the nephron filtrate. These studies will provide important new insights about an essential but understudied cellular mechanism that will be required for in vivo engraftment of new kidney tissue-based renal regeneration therapies.

Abstract The Mount Desert Island Biological Laboratory (MDIBL), in collaboration with The Jackson Laboratory, and the Maine Medical Center Research Institute, proposes a conference series on Stem Cells and Aging to be held annually in July of 2020, 2021, and 2022 at MDIBL with the support of the NIA. This conference builds on a strong tradition of stem cell conferences at MDIBL that were first offered in 2002. The proposed series for 2020- 2022 will focus on stem cells and aging, addressing questions related to the causes of aging-associated failure of stem cell quiescence and activation, the impact of stem cell-extrinsic versus stem cell-intrinsic mechanisms in aging associated dysregulation, and new approaches to delay aging by stabilizing stem cell quiescence or reducing stem cell vulnerability. This conference will be followed by a two-week course at MDIBL iCARB: Immersion in Comparative Aging and Regenerative Biology that trains graduate students, postdoctoral fellows, and career scientists to become leaders in Aging and Regeneration research. The Organizing Committee, made up of national leaders in biomedical and stem cell research, has developed the program of this symposium to address current issues important to both the stem cell and aging research communities. The specific aims of the 2020 symposium are: 1) Present and discuss research studies of aging related pathologies that impact stem cells and regeneration including DNA damage / mutation, inflammation, altered cell metabolism / ROS generation, and aging-related changes in stem cell quiescence; 2) Present and discuss scientific advances defining cell-intrinsic and -extrinsic mechanisms governing stem cell aging including transcriptional programs, epigenetic programs, niche cell communication, and niche composition; 3) Present and discuss research on comparative aspects of aging (human, mouse, fish, worm, fly) with a focus on broadly conserved cellular changes in aging; 4) Present and discuss research on promoting stem cell-based tissue regeneration and rejuvenation in aging including studies of caloric restriction and stem cells, inflammatory signaling in aged stem cells, and niche engineering; and 5) Provide extensive opportunities for interaction between trainees, investigators new to stem cell research, and investigators well established in these research areas. Scientific sessions will include platform presentations, poster sessions, and a trainee/faculty networking lunch.

ADMINISTRATIVE CORE PROJECT SUMMARY COBRE Phase I, Comparative Biology of Tissue Repair, Regeneration and Aging, supported the development and growth of the Kathryn W. Davis Center for Regenerative Biology and Medicine (Davis Center). The Davis Center is the major research focus of the MDI Biological Laboratory (MDIBL). COBRE Phase II will support three Project Leaders and two scientific cores, and will continue to support the growth of the Davis Center in order to establish a critical mass of investigators and a self-sustaining research program. The Administrative Core is critical to the management and success of COBRE Phase II. The COBRE PD/PI and Administrative Core Director, Dr. Kevin Strange, has primary responsibility for administering the program and overseeing the development of the COBRE, its faculty and its cores. He is assisted by the Administrative Core Co-Director, Dr. Nadia Rosenthal, and Program Coordinator, Ms. Amy Somes. Decisions regarding budgets, core usage and direction of the COBRE are made by the Director and Co-Director with advice from the External Advisory Committee (EAC) and Internal Advisory Committee (IAC). Leadership and oversight includes coordination and integration of Project Leader research programs with Center resources and activities; establishing and managing the allocation of Center resources; organizing Center activities; organizing EAC and IAC meetings; management of a rigorous faculty career development plan; faculty and program evaluation; faculty recruitment; and interactions with other groups to further COBRE goals. COBRE Phase I supported four early-career Project Leaders and one mid-career Project Leader. Phase I was highly successful both from formative and summative standpoints. All five Project Leaders graduated from Phase I with independent research program grant support and achieved multiple other successes including publication of significant peer-reviewed papers, creation of patented/patentable intellectual property, receipt of foundation and R21 grants, significant peer recognition and, for the mid-career Project Leader, a major and productive change in his laboratory research direction. The success of Phase I is directly attributable to the implementation of a rigorous career development plan that will be utilized in Phase II. Elements of this plan include a rigorous faculty recruitment process, biannual EAC reviews, biannual Project Leader career SWOT analyses and scientific advisor reviews, mandatory grant proposal development and review, peer-to-peer mentoring, and regular group meetings and meetings with the Administrative Core Director and Co-Director. MDIBL?s long-term strategic scientific goal is to build a world-class research program in regenerative biology and medicine. The Davis Center will remain MDIBL?s sole research focus for the foreseeable future and its sustainability is therefore of the highest priority to MDIBL leadership. Sustainability will be achieved by establishing a critical mass of investigators working at the forefront of regenerative and aging biology.