Jill M. Weimer, Ph.D. - US grants

[unreadable] DESCRIPTION (provided by applicant): Radial glial cells are critical for the proper formation of the mammalian brain, providing both a source of new neurons as well as a scaffold for neuronal migration. These functions of depend on the structural and molecular polarity of radial glia and disruption in any aspect of their development, differentiation, and neuronal interaction can lead to aberrant placement of cells within the brain. Radial glia are one of the most strikingly polarized cells in the developing nervous system and disruption in this polarity can result in gross malformation within the brain, such as lissencephaly, polymicrogyria, and heterotopias. To explore the regulation of polarity in these cells, we have focused on molecular signaling events regulated by neuregulin 1 (NRG1) and its receptor, ErbB. In particular, having established that signaling through this receptor complex is important in establishing and maintaining polarity within radial glial cells, we will determine whether activation of principal determinants in cell polarity are regulated through ErbB signaling. Furthermore, we will investigate whether induction of ErbB2 in the adult brain is sufficient to revert astrocytes to radial glia. Study of these molecular events will significantly contribute to understanding of mammalian brain development. [unreadable] [unreadable]

PROJECT SUMMARY (See Instnjctions): During cortical development, neuronal progenitors proliferate and then migrate away from the ventricular zone (VZ) to take up residence in the cortical plate (CP). These immature cells take one of two paths upon exiting the VZ: 1) migrating directly along the radial glia scaffold to the CP, taking up residence in an inside out fashion or 2) they migrate to the subventricular zone (SVZ) and take on a multipolar morphology to become intermediate progenitors (IPs), undergo an additional round of cell division before continuing on their way to the CP. Although disruption in these events are known to contribute to pediatric neurodevelopmental disorders, the factors regulating progenitor retention in, and release from, unique neurogenic niches are not well understood. Small RhoGTPases, including cdc42 and RhoG, serve as regulators of progenitor proliferation and fate determination within the developing cortex. The mechanisms regulating RhoGTPases particularly in the developing nervous system, are not well understood. These regulators, comprised of GEFs and GAP) control the GTP-loading state, and thus activity, of RhoGTPases. Because GEFs act as activators for RhoGTPase, we hypothesize that GEFs are critical to RhoGTPase-mediated regulation of progenitor proliferation and fate determination in the developing cerebral cortex. We sought to identify GEFs with restricted expression in neurogenic niches of the developing cerebral cortex. Our efforts led us to a small guanine exchange factor (SGEF) whose expression is restricted to the VZ/SVZ during the peak of neurogenesis. SGEF is known to induce formation of F-actin rich protrusions on fibroblasts and endothelial cells (1-2). In support of a role for SGEF in the developing cerebral cortex, mice deficient in SGEF {SGEF^') exhibit reduced neural progenitor proliferation in the SVZ. We will use three aims to test our hypothesis: Aim I: Can altered GEF expression mediate changes in the behavior of immature neurons? Aim II: Do GEFs selectively influence the proliferation and placement of neural progenitors? Aim III: By what mechanism(s) does SGEF regulate the developing cerebral cortex? These studies seek to uncover the mechanism and functional regulation of GEFs in the development of the mammalian cerebral cortex. By focusing on SGEF, whose expression is restricted to a defined neurogenic niche in the developing cerebral cortex and whose deletion appears to have nominal consequences outside of the central nervous system, we are able to use the developing cerebral cortex as a model to uncover clues about how GEFs function to regulate RhoGTPase signaling. '

DESCRIPTION (provided by applicant): The neuronal ceroid lipofuscinoses (NCLs) are a family of devastating neurodegenerative diseases resulting from mutations in as many as 14 different genes. Researchers have long sought a molecular link between various NCLs. Recent studies suggest a common NCL pathway associated specifically with membrane associated protein forms of the disease (CLN3, CLN6, CLN5, CLN8) may be intracellular transport via disrupted interaction with the cytoskeletal network. In support of this concept, we have identified a novel complex containing the ER-associated CLN6, whose mutation results in a variant late infantile NCL (vLINCL), the collapsin response mediator protein 2 (CRMP2), and the kinesin motor protein, KLC4. Acting through a network of protein interactions, CRMP2 regulates axonal/dendritic specification and extension during neurodevelopment and contributes to maintenance/regeneration in the mature brain. We hypothesize that the CRMP2/CLN6/KLC4 (CCK) complex utilizes CLN6 as a molecular tag on ER-vesicles for segregation of cargo to distal sites in dendrites and axons. Disruption of this signaling complex could contribute to the pathogenesis of vLINCL through altered neuronal process outgrowth and maintenance. To test this hypothesis, we propose aims that will 1) determine how the CCK complex regulates ER-vesicle transport development and maintenance of neurons; 2) define how CCK complex transport is linked to early events in neuronal differentiation and identify what cargo is transported by CLN6-tagged vesicles; and 3) determine if stabilization of CRMP2-associated complexes, independent of CLN6 rescue, could ameliorate neurological deficits in a pre- clinical NCL mouse model. These studies will expands our understanding of CLN6's contribution to crucial cellular processes and start to unravel the biological significance of the CCK complex in developing and mature neurons, as well as its role and the role of intracellular trafficking in neurological disorders such as the NCLs.

Project Summary Providing medical students with meaningful research experiences during their training is an important piece in generating physicians who incorporate research into their careers. There is a strong need for research aware clinicians in rural areas in the Upper Midwest. Having a cadre that focuses its efforts in the area of pediatric medicine will also be important in addressing the health disparities seen in rural and American Indian populations. The ultimate goal of the DRPMS is to help meet the future needs of health-related research by contributing to the development of physicians who will be well- prepared to use evidence-based medicine in practice and contribute to translational research. The Northern Plains have a large number of health disparities among the children and adolescents. Thus there is a compelling need to support and promote the training of the physicians in training in developmental research. Faculty members at the Sanford School of Medicine are strong in research focused on development: prenatal development, postnatal development, diseases and issues of children and adolescents. The Developmental Research Program for Medical Students (DRPMS) proposed here will help provide medical students with exposure to research areas of development in order to kindle their interest in pursuing this as part of their careers. The Sanford School of Medicine has recently integrated its curriculum. As an extension of this, the school is in the process of developing a strategy to integrate research into the educational experience of all medical students as a required educational activity. While the school of medicine has always had ad hoc programs for medical students to participate in research, the program proposed in this application will provide a structured program that involves research but includes an additional seminars series on career development, including how to incorporate scholarship, as well as responsible conduct of research. The Program Directors will be assisted in the management of the program by an Executive Committee and an Internal Advisory Committee. Six students per year will be accepted into the DRPMS. There will be specific strategies employed to increase the number of trainees from diverse and disadvantaged backgrounds. Selection of the trainees will be done by the Executive Committee. The research progress will be followed by the mentor(s) and the PDs. After completion of the program trainees will be invited back to become peer mentors or to continue on with research outside of the program. Intermediate and longitudinal follow- up of the trainees will be performed as part of the program's evaluation.

PROJECT SUMMARY The Pediatric Biomedical Research Program at Sanford Research will provide research experiences in pediatric biomedical science to undergraduate students in South Dakota, support the pursuit of scientific careers, and increase diversity in the scientific community. Sanford Research is a hub for pediatric research with a track record of student training at all levels. Through integration of cutting-edge research experiences, career and professional development workshops, presentation opportunities, peer mentoring, and outreach activities, we will accomplish the following aims: I. Grow scientific career training opportunities in South Dakota by building career pipelines and preparing students for the growing biomedical workforce; II. Expand student exposure to the scientific workforce through interaction with scientists at all career levels, peer mentoring opportunities, and career and professional development programming; III. Increase diversity in the scientific community by training underrepresented students for science careers; IV. Enhance regional community awareness of science through outreach activities aimed at educating and inspiring community members and the next generation of scientists. With a growing biomedical workforce demand and limited training opportunities within South Dakota, the Pediatric Biomedical Research Program will be a vital resource to train undergraduate students in pediatric research and prepare them for biomedical career opportunities in this dynamic and rapidly growing region.

Overall Summary The purpose of the Transdisciplinary Center for Population Health (TCPH) COBRE is to facilitate the development of American Indian (AI) and rural health research in South Dakota. The theme that defines this center is the application of an ecological framework to address important issues in AI and rural health populations. All of the projects incorporate transdisciplinary teams, including perspectives directly from the involved populations. This initial and continuous engagement creates an environment where research results can be immediately disseminated and applied. These selected Project Leaders have each started down the path towards research independence and are on the cusp of being competitive at the R01 level. This proposed COBRE center will allow for the needed mentorship and concentrated funding for that development to occur. These Project Leaders will then graduate off of COBRE funding, assume larger mentorship roles within the center, and allow for the recruitment of new researchers to build our capacity and increase the impact of research on AI and rural health. A plan has been created with national training institutes that specialize in AI and rural health research to help draw a new group of talented, energetic and creative researchers to the region. The TCPH includes core services that focus on the unique regulatory needs of human subjects research, particularly the complexity that exists with multiple research partnerships, and data management and statistical tools to optimize the quality and utility of data.

PROJECT SUMMARY Rare diseases are defined as those diseases affecting less than 1 in 5000 patients in the US. Although singularly rare, combined there are over 7000 rare disease that affect approximately 1 in every 10 Americans. For these patients, it is often difficult to find or build patient support networks or gain access to the latest research on their particular rare disease. The team in the Sanford Research's Coordination of Rare Diseases at Sanford (CoRDS) registry program has a nine-year history of hosting an annual rare disease symposium for medical professions, scientists, rare disease patients, and patient advocates. This event, which started as a grassroots effort, serves as a collaborative research summit drawing attendees from across the Great Plain states. With this proposal, our goal is to grow this once one-day event into a multi-day Great Plains Rare Disease Summit that will provide access to the highest standard of scientific and clinical research in a format that is accessible to patients, advocates and community members. Incorporating this mix of attendees encourages communication between the research and patient communities. Investigators will come away from the meeting having heard the patient's story and have a better understanding of how the disease impacts the person. Likewise, patients and advocates will come away with a better scientific understanding of their condition and can go back to their communities as more effective and energized advocates for rare disease research and awareness. Although rare disease events are held across the US, none are held consistently in the Great Plains region. For families and patient advocacy groups with high medical costs and health barriers, attending these events can be cost prohibitive or logistically challenging. By bringing the conference to the region in which they live, we are providing a much needed, mutually beneficial connection to the research world. Our objective is to establish the Great Plains Rare Disease Summit as a destination conference for scientists, medical professionals, patients, advocates, and industry throughout the US. Each year, the conference will promote groundbreaking research in rare diseases and provide an important avenue for conversation between scientists, clinicians, and those affected by the diseases they study and treat. We will achieve these objectives by 1) providing rural rare disease patients, caregivers and advocates access to a high quality rare disease education and support; 2) providing a forum for experts to present cutting edge research; 3) building up the rare disease community in the region for patients, caregivers, and advocates; and 4) developing an innovative new program that promotes rare disease education and research in the Great Plains.

CLN3 Batten disease is a fatal lysosomal storage disorder (LSD) resulting from autosomal recessive mutations in CLN3. The disease progresses from vision loss in early childhood to seizures, motor decline, cognitive disability and dementia, with a typical life expectancy of 15-30 years of age. There is no cure for CLN3 Batten and the only treatments available address some disease symptoms, but do not delay disease progression. The discovery of an effective treatment for CLN3 Batten has been hindered by a lack of understanding of the protein's function and the underlying mechanisms leading to neurodegeneration. The goal of this proposal is to test a therapeutic approach for CLN3 Batten that employs antisense oligonucleotides (ASOs) and in so doing, elucidate mechanisms of neurodegeneration in this disease that will inform research and discovery of effective treatments for Batten diseases and other LSDs. Most cases of CLN3 Batten are caused by deletion of exons 7 and 8 (CLN3?78), which results in an open reading frame shift and a premature termination codon. We hypothesize that using ASOs to redirect pre-mRNA splicing and correct the reading frame of CLN3?78 mRNA will partially restore protein function and have a therapeutic effect in CLN3 Batten disease. Our preliminary findings support our hypothesis, demonstrating that restoring the CLN3?78 reading frame alleviates dysfunction associated with disease in both cell and animal models. We will test our hypothesis in the proposed project with the aims to 1) compare the function of the wild type and novel CLN3 isoforms, 2) develop an approach using ASOs to increase CLN3?ex78 isoforms, 3) assess ASO treatments for CLN3 Batten disease using human cell lines as well as mouse and 4) porcine models of CLN3 Batten disease. Collectively, this study will allow us to better understand the function of the CLN3 protein and the utility of ASOs in treating CLN3 Batten disease.