Adam R. Ferguson, Ph.D. - US grants

DESCRIPTION (provided by applicant): Spinal cord injury (SCI) is a devastating syndrome, affecting approximately 250,000 people in the USA and costing 9.7 billion dollars annually. SCI is characterized by an acute loss of cells with the initial insult, followed by a secondary phase of cell death over several hours and days. Our long-term goal is to understand the mechanisms of this secondary cell death so that we can design drugs that spare tissue and improve function after SCI. The specific hypothesis is that the cytokine tumor necrosis factor alpha (TNFa) released after SCI facilitates excitotoxic cell death by enhancing membrane localization of AMPA receptors (AMPARs). This hypothesis is based on findings that 1) TNFa and glutamate levels rise after SCI;2) TNFa enhances cell death caused by kainate (KA), an agonist of AMPARs;3) TNFa causes trafficking of AMPA receptors to the cell membrane in vitro;4) TNFa-induced AMPA receptor trafficking in vitro is selective for Ca++ permeable AMPARs. The specific aims are to test: 1) whether SCI induces AMPA trafficking at time points when TNF levels are known to be elevated 2) whether TNFa nano-injection induces AMPAR trafficking in vivo.

DESCRIPTION (provided by applicant): Spinal cord injury (SCI) produces a multifaceted syndrome characterized by loss of mobility, loss of bladder, bowel and sexual function, pathological pain, and a loss of autonomy. The past 20 years have seen significant progress in our ability to emulate many features of human SCI in animal models, yet few experimental therapies have translated from the laboratory to human patients. One major obstacle to translation is the lack of information about which outcome metrics for SCI are comparable across different laboratories, strains, types of injuries, and species. Identification of these important common outcome metrics is a major goal of the proposed project. We hypothesize that experimental SCI produces a bio-behavioral syndrome that is reflected not by only one outcome, but rather consistent patterns across many different outcomes. This view is implicitly assumed by many experimental SCI researchers when they evaluate experimental therapeutics using several outcomes from the same experimental subjects. However these data have not been analyzed using sophisticated multivariate information processing procedures which are designed to detect, measure, and quantify disease patterns in complex datasets. By pooling data from several laboratories and making cross- species comparisons, we will leverage existing experimental data to identify common metrics of SCI that can be used for evaluating mechanism of SCI that translate across species. We propose the following Aims: 1) Build a pooled database of existing experimental rodent and primate SCI research data to provide a platform for knowledge discovery and multivariate quantification across diverse outcomes and experimental models. We will start with data from 5 major SCI research centers to provide a framework for later contributions from other research groups. 2) Identify syndrome measures in rodent SCI models, using the same multivariate techniques often used by clinical researchers to define and measure complex disease states. 3) Identify which multivariate outcome patterns in rodent models are most sensitive to the effects of graded injury and which are most sensitive to change over time, with the goal of improving sensitivity and streamlining testing of therapeutic interventions. 4) Identify which multivariate outcome patterns in non-human primates are most sensitive to the effects of SCI and recovery over time, providing important information about the most sensitive outcomes for therapeutic testing in this valuable preclinical model. 5) Make translational multivariate comparisons of rodent and primate SCI data to identify which outcome patterns best translate across experimental models and which are species- and model-specific, setting the stage for future multivariate comparisons to human data. This represents a new direction for the field of experimental SCI and we expect this approach to help define outcome metrics that are comparable across species, facilitating translational SCI research. PUBLIC HEALTH RELEVANCE: The proposed Project focuses on spinal cord injury, a devastating syndrome, affecting approximately 250,000 people in the United States, and costing the nation almost 10 billion dollars per year in healthcare and loss-of- productivity. Injured individuals are plagued by loss of mobility;loss of bladder, bowel and sexual function;pathological pain;and a loss of autonomy. These changes profoundly reduce the quality of life for injured individuals and their loved ones.

DESCRIPTION (provided by applicant): Prior research has shown that neurons within the spinal cord are sensitive to response-outcome (instrumental) relationships. Rats with complete spinal cord transections can learn to maintain the hindlimb in a flexed position if leg shock is delivered when the leg is extended (response- contingent shock). Using this simple preparation, we have shown that stimulation alters the capacity for spinal learning in a bidirectional manner. Training with response-contingent shock promotes later spinal learning. Conversely, nociceptive stimulation that is independent of leg position (uncontrollable shock or peripheral paw injury) inhibits future spinal learning and impairs locomotor recovery after contusive spinal cord injury (SCI). Prior work has found that these impairments in spinal learning depend on a maladaptive form of glutamate-mediated plasticity that impairs future use-dependent plasticity in the spinal cord. The cellular mechanisms regulating this plasticity of plasticity (metaplasticity) are not well-understood. Our hypothesis is that the cytokine tumor necrosis factor a (TNFa) within the spinal cord plays a critical mechanistic role in spinal learning impairments after uncontrollable stimulation. TNFa is released in elevated levels after SCI or nociceptive stimulation. TNFa has recently been found to alter synaptic plasticity within the injured spinal cord by increasing trafficking of the glutamate AMPA receptor (AMPAR) to the plasma membrane of spinal neurons. Preliminary data suggest that TNFa-induced AMPAR trafficking may contribute to spinal learning impairments after SCI. Intrathecal delivery of an AMPAR agonist or TNFa impairs spinal learning. Conversely a TNFa inhibitor promotes spinal learning. Aim 1 establishes the dose-response and temporal features of these TNFa-mediated effects. Aim 2 evaluates TNFa mRNA and protein levels in the spinal cord after uncontrollable stimulation using qRT-PCR, ELISA, in situ hybridization and immunofluorescence. Aim 3 examines TNF-induced trafficking of AMPARs to the plasma membrane of spinal neurons after uncontrollable stimulation by biochemical and confocal microscopy methods. Aim 4 tests the therapeutic potential of a TNFa1 inhibitor for promoting use-dependent plasticity and recovery of function after contusive SCI. Our long-term goal is to unravel the mechanisms that regulate adaptive spinal plasticity, allowing patients to re-establish essential functions, while limiting the maladaptive plasticity that can lead to spasticity or intractable pain. By defining key mechanisms that disable spinal cord learning and recovery of function, we hope to provide novel therapeutic targets that promote spinal cord learning and neurorehabilitation after SCI. PUBLIC HEALTH RELEVANCE: Project Narrative/Public Health Relevance Statement Spinal cord Injury (SCI) produces a devastating syndrome that is characterized by loss of motor control and mobility, as well as sensory dysfunction and pain. The proposed project explores cellular mechanisms that regulate a form of spinal cord learning that is thought to contribute to recovery of function after SCI. These studies may provide a novel target for improving recovery after SCI.

? DESCRIPTION (provided by applicant): Spinal cord Injury (SCI) produces a devastating syndrome characterized by loss of motor function, hyper- reflexia, spasticity, and pain. The long-term goal of SCI therapy is to promote adaptive spinal plasticity for restoration of function while limiting maladaptive plasticity that results in hyper-reflexia, spasticity and intractable pain. Recent research has indicated that both adaptive and maladaptive CNS plasticity can occur at the level of the spinal cord to dictate recovery of function. However, the specific conditions that promote adaptive versus maladaptive spinal plasticity in SCI are not well-understood. Our central hypothesis is that maladaptive spinal plasticity is predicated upon aberrant peripheral stimulation in the acute phase of SCI. This hypothesis has strong clinical/translational relevance, as epidemiological studies indicate that peripheral injuries are prevalent comorbidities in human SCI. Our preliminary experimental data suggest that peripheral nociceptive stimulation delivered caudal to a complete SCI lesion produces maladaptive spinal plasticity that manifests as tactile hyper-reflexia and spasticity. Similar effects are observed wih nerve injury below the SCI lesion. Our findings link these effects to specific alterations in glutamate receptor-mediated synaptic plasticity in the spinal ventral horn, providing a novel therapeutic target for restoration of function after SCI. The Aims expand on the preliminary data to: 1) test the specific impact of nociceptive stimulation below SCI on hyper- reflexia/spasticity, 2) evaluate synaptic mechanisms involved, and 3) test an intervention for combating maladaptive plasticity to promote adaptive recovery in a clinically-relevant model of contusive SCI. The proposed project has implications for therapeutic targeting in polytraumatic SCI-a prevalent clinical presentation where CNS lesions are accompanied with peripheral injuries.

PROJECT SUMMARY: Trauma to the spinal cord and brain (neurotrauma) together impact over 2.5 million people per year in the US, with economic costs of $80 billion in healthcare and loss-of-productivity. Yet precise pathophysiological processes impacting recovery remain poorly understood. This lack of knowledge limits the reliability of therapeutic development in animal models and limits translation across species and into humans. Part of the problem is that neurotrauma is intrinsically complex, involving heterogeneous damage to the central nervous system (CNS), the most complex organ system in the body. This results in a multifarious CNS syndrome spanning across heterogeneous data sources and multiple scales of analysis. Multi-scale heterogeneity makes spinal cord injury (SCI) and traumatic brain injury (TBI) difficult to understand using traditional analytical approaches that focus on a single endpoint for testing therapeutic efficacy. Single endpoint-testing provides a narrow window into the complex system of changes that describe the holistic syndromes of SCI and TBI. In this sense, complex neurotrauma is fundamentally a problem that requires big- data analytics to evaluate reproducibility in basic discovery and cross-species translation. For the proposed TOP-VISION cooperative agreement we will: 1) integrate preclinical neurotrauma data on a large-scale; 2) develop novel applications of cutting-edge multidimensional analytics to make sense of complex neurotrauma data; and 3) validate bio-functional patterns in targeted big-data-to-bench experiments in multi-PI single center (UG3 phase), and multicenter (UH3 phase) studies. The goal of the proposed project is to develop an integrated workflow for preclinical discovery, reproducibility testing, and translational discovery both within and across neurotrauma types. Our team is well-positioned to execute this project given that with prior NIH funding we built one of the largest multicenter, multispecies repositories of neurotrauma data to-date, housing detailed multidimensional outcome data on nearly N=5000 preclinical subjects and over 20,000 curated variables. We will leverage these existing data resources and apply recent innovations from data science to render complex multidimensional endpoint data into robust syndromic patterns that can be visualized and explored by researchers and clinicians for discovery, hypothesis-generation and ultimately translational outcome testing.

PROJECT SUMMARY: Trauma to the spinal cord and brain (neurotrauma) together impact over 2.5 million people per year in the US, with economic costs of $80 billion in healthcare and loss-of-productivity. Yet precise pathophysiological processes impacting recovery remain poorly understood. This lack of knowledge limits the reliability of therapeutic development in animal models and limits translation across species and into humans. Part of the problem is that neurotrauma is intrinsically complex, involving heterogeneous damage to the central nervous system (CNS), the most complex organ system in the body. This results in a multifarious CNS syndrome spanning across heterogeneous data sources and multiple scales of analysis. Multi-scale heterogeneity makes spinal cord injury (SCI) and traumatic brain injury (TBI) difficult to understand using traditional analytical approaches that focus on a single endpoint for testing therapeutic efficacy. Single endpoint-testing provides a narrow window into the complex system of changes that describe the holistic syndromes of SCI and TBI. In this sense, complex neurotrauma is fundamentally a problem that requires big- data analytics to evaluate reproducibility in basic discovery and cross-species translation. For the proposed TOP-VISION cooperative agreement we will: 1) integrate preclinical neurotrauma data on a large-scale; 2) develop novel applications of cutting-edge multidimensional analytics to make sense of complex neurotrauma data; and 3) validate bio-functional patterns in targeted big-data-to-bench experiments in multi-PI single center (UG3 phase), and multicenter (UH3 phase) studies. The goal of the proposed project is to develop an integrated workflow for preclinical discovery, reproducibility testing, and translational discovery both within and across neurotrauma types. Our team is well-positioned to execute this project given that with prior NIH funding we built one of the largest multicenter, multispecies repositories of neurotrauma data to-date, housing detailed multidimensional outcome data on nearly N=5000 preclinical subjects and over 20,000 curated variables. We will leverage these existing data resources and apply recent innovations from data science to render complex multidimensional endpoint data into robust syndromic patterns that can be visualized and explored by researchers and clinicians for discovery, hypothesis-generation and ultimately translational outcome testing.

PROJECT SUMMARY/ABSTRACT Trauma to the central nervous system (CNS: spinal cord and brain) together affect more than 2.5 million people per year in the US, with economic costs of $80 billion in healthcare and loss-of-productivity. Yet, the precise pathophysiological processes impairing recovery remain poorly understood. This lack of knowledge is exacerbated by poor reproducibility of findings in animal models and limits translation of therapeutics across species and into humans. Part of the problem is that neurotrauma is intrinsically complex, involving heterogeneous damage to the central nervous system (CNS), by far the most complex organ system in the body. This results in a multifaceted CNS syndrome reflected across heterogeneous endpoints and multiple scales of analysis. Multi-scale heterogeneity makes traumatic brain injury (TBI) and spinal cord injury (SCI) difficult to understand using traditional analytical approaches that focus on a single endpoint for testing therapeutic efficacy. Single endpoint-testing provides a narrow window into the complex system of changes that describe SCI and TBI. Understanding these disorders involves managing datasets that include high volume anatomy data, high velocity physiology decision-support data, the high variety functional/behavioral data, and assessing correlations among these endpoints. In this sense, neurotrauma is fundamentally a data management problem that involves the classic ?3Vs of big data? (volume, velocity, variety). Of these, variety is perhaps the greatest data challenge in neurotrauma research for reproducibility in basic discovery, cross-species translation, and ultimately clinical implementation. For the proposed Data Repositories Cooperative Agreement (U24) we will build on our prior work managing data variety in the Open Data Commons for SCI (odc-sci.org) and TBI (odc-tbi.org) to make neurotrauma data Findable, Accessible, Interoperable, and Reusable (FAIR). The milestone-driven aims will: 1) further develop and harden our data lifecycle management system with end-to-end data version control and provenance tracking, data certification, and data citation; 2) develop in-cloud data dashboards and visualizations to monitor data quality and to promote data reuse, exploration, and hypothesis generation; 3) establish a pan- neurotrauma (PANORAUMA) data commons that brings together separate data assets currently supported by our multi-PI (MPI) team by aligning a patchwork of governance structures and policies. The goal of the proposed project is to develop a pooled repository for preclinical discovery, reproducibility testing, and translational discovery both within and across neurotrauma types. Our team is well-positioned to execute this project given that we developed some of the largest multicenter, multispecies neurotrauma data repositories of neurotrauma to-date (N>10,000 subjects 20,000 curated variables); the Neuroscience Information Framework (NIF); data terminologies and standards for these fields (MIASCI, NIFSTD); and policy work with the International Neuroinformatics Coordinating Facility (INCF). The PANORAUMA cooperative agreement is highly responsive to PAR-20-089, leveraging early successes in SCI and TBI data sharing to improve quality and sustainability.