James R. Pauly - US grants

animal tissue; substance abuse related disorder; radiography; nervous system; infant mortality; Mammalia; biomedical resource; mother /infant health care; psychology; behavioral /social science research tag;

Trauma to the CNS initiates acute and secondary cascades of biochemical and metabolic changes often results in a state of persistent neurological dysfunction. Understanding the neurochemical alterations that occur following damage to the CNS is critical for the development of therapeutic strategies that can prevent and/or remediate the detrimental effects of trauma. The neurobiological basis for the protracted memory deficit that commonly occurs following traumatic brain injury (TBI) is not clearly understood although a number of studies have suggested that deficits in the CNS cholinergic system play a prominent role. However, most of the previous studies have focused on muscarinic, rather than nicotinic cholinergic receptor mechanisms. This is surprising since deficits in the nicotinic receptor system have been repeatedly associated with the cognitive deficit that occurs to neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease. Our initial studies clearly demonstrate that a cortical contusion injury (CCI) causes significant and widespread defects in hippocampal and cortical alpha 7 nicotinic receptor (nAChr) expression. The working hypothesis of the proposed studies is that changes in the CNS alpha7 nAChr's contribute significantly to head trauma- induced cognitive dysfunction. Furthermore, we predict that pharmacological modulation of alpha7 neuronal nicotinic receptors will have neuroprotective and cognitive-enhancing properties in head-injured rats. The Specific Aims of this proposal will evaluate: 1) the time course of changes in alpha7 protein and message expression following TBI 2) neuroprotective actions of nicotinic receptor antagonists administered in the acute phase of TBI, 3) cognitive enhancing properties of nicotine and selective alpha7 agonists administered acutely (or chronically) in the delayed phase of TBI 4) the effects of TBI on deficits in auditory sensory gating and 5) restoration of sensory gating following treatment with nicotine and other selective alpha7 agonists.

[unreadable] DESCRIPTION (provided by applicant): Neuropsychological development is frequently impaired in children exposed to prenatal tobacco smoke, even after adjusting for other possible genetic and environmental confounds. Although the causative agents in tobacco smoke that lead to altered development are not known, accumulating evidence from animal studies suggests that nicotine may play a crucial role. However, in most animal studies nicotine has been administered acutely to naive dams, leading to significant fetal hypoxia and increased levels of stress hormones, which could contribute to an unfavorable fetal environment. Our previous studies have shown that oral nicotine exposure is a stress free and effective method for delivery of nicotine to pregnant mice. Oral nicotine delivery to pregnant mice causes persistent, gender-dependent changes in baseline behavior and sensitivity to nicotine in the progeny. In this proposal we will study one possible neurochemical mechanism that may underlie behavioral teratogenicity produced by developmental nicotine exposure. We propose a thorough and systematic evaluation of changes in structure/function of dopaminergic and nicotinic cholinergic neuronal systems following prenatal nicotine administration. The underlying hypothesis of this proposal is that prenatal nicotine exposure changes the temporal and anatomical patterns of apoptotic cell death in the developing mouse nervous system. Inhibition of apoptotic cell death in the CNS may cause permanent molecular, cellular or neurochemical changes that predispose animals to have altered sensitivity to drugs and/or susceptibility to drug seeking and relapse. These studies will provide a thorough assessment of changes in cholinergic and dopaminergic neurotransmission following prenatal nicotine exposure. In light of consistent evidence that enhancement of dopamine (DA) neurotransmission may be important for nicotine reinforcement/addiction, we believe that evaluation of dopaminergic function is the most relevant target for mechanistic studies to unravel the causes of nicotine induced behavioral teratogenicity. These studies are relevant to public health since nicotine replacement therapy is commonly prescribed for women that are pregnant and wish to stop smoking tobacco. We believe that nicotine plays a significant role in the negative outcomes that have been frequently associated with in utero tobacco smoke exposure. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): The recent failure of several Phase III clinical trials (pharmacological and non-pharmacological) in patients with head injury underscores the need for improved therapeutic modalities. TBI in humans is a heterogeneous condition that differs substantially in severity, location, etiology, clinical presentation and neuropathology. This differs from experimental TBI studies where multiple variables are carefully controlled. The acute and chronic molecular, cellular, biochemical and pathophysiological events that follow TBI are complex and multi-factorial. There may not be a single "magic bullet" drug that will be completely successful in preventing secondary damage following brain injury. Rather, combinatorial drug treatments that target specific windows of secondary pathology may be more efficacious than treatment with a single drug. In the proposed experiments, the PIs will evaluate cellular and functional outcomes following TBI and administration of Cyclosporin A (CsA), followed by dietary choline supplementation. The combination of CsA and choline was chosen based on the clinical utility of these drugs, previously published work, and preliminary data generated by the Pauly/Scheff/Sullivan labs. The overall hypothesis of this proposal is that a combinatorial approach will optimize outcome compared to single or dual treatment modalities. The experiments will advance the understanding of the neurobiological consequences of TBI and determine the efficacy of a combined pharmacological/behavioral approach to recovery in two different models of brain injury. The outcome measures proposed will provide important new information about neurobiological outcomes following TBI. Animal studies in TBI have generally not utilized combinatorial approaches to therapy. However, given the variability and complexity of human brain injuries, a treatment strategy that uses multiple agents, targeted at specific neuropathological events, seems to be a pragmatic approach that may optimize outcome. The studies proposed for this research are highly significant and could add to our understanding of the pathophysiology and therapeutic treatment of individuals with traumatic brain injuries. If the studies show benefit of combining CsA and choline, the PIs will meet with clinical investigators to see if this could possibly be a new trial or an add-on to the CsA trial under consideration for funding. Although the pharmacological experiments proposed are not particularly mechanistic, they are feasible and directly translatable into human patients. The NIH road map contends that if therapeutics are directly translatable to humans, mechanistic studies are not the initial priority. Two different models of rat TBI will be used in these experiments, the cortical contusion model of focal injury, and the medial fluid percussion model of diffuse injury. The combined outcome measure the PIs will test may provide better characterization of recovery than previously used in either the CCI or MFPI model. Finally, functional recovery in terms of cognition is a major focus of this grant. These studies are translational since both cyclosporin and choline are both approved for use in human patients. However, the animal literature has gaps, especially for the effects of CsA on cognitive recovery. Choline is readily available and could be administered to TBI patients outside of a critical care setting. Animal studies in TBI have generally not utilized combinatorial approaches to therapy. However, given the variability and complexity of human brain injuries, a treatment strategy that uses multiple agents, targeted at specific neuropathological events, seems to be a pragmatic approach that may optimize outcome. PUBLIC HEALTH RELEVANCE: The recent failure of several Phase III clinical trials (pharmacological and non-pharmacological) in patients with traumatic brain injury (TBI) underscores the need for improved therapeutic modalities. The overall hypothesis of this proposal is that a combinatorial approach with cyclosporin A (CsA) and dietary choline supplementation will optimize outcome compared to single treatment modalities. CsA and choline are both approved by the FDA and actively being pursued in NIH-sponsored trials as monotherapy for human TBI patients. The PIs'hypothesis will be evaluated in two different models of rat TBI that have different mechanisms and timing of neuropathology. These studies are a logical extension of current trials in TBI, and will use a set of testable hypotheses to provide clinically relevant information about this drug combination.

Lafora disease (LD) is a fatal childhood epilepsy and a non-classical glycogen storage disorder with no treatment or cure. Over the last 15 years, we and others have defined the molecular underpinnings of LD that position the field to cure this horrific disease. A hallmark of LD is cytosolic aberrant glycogen-like inclusions known as Lafora bodies (LBs) that accumulate in cells of most tissues, including the brain. Like patients, LD mouse models present with LBs and neurodegeneration. Reduced glycogen synthesis via genetic methods eliminates LB formation and rescues the neurological phenotype in LD mouse models. Thus, a current focus in the field is to decrease LBs with the goal of treating LD. Valerion Therapeutics has engineered a cell delivery platform utilizing antibody fragments allowing their antibody-enzyme fusions (AEFs) to deliver a protein into a myriad of cells. In collaboration with Valerion, we recently identified therapeutic strategies to clear LBs. This involves use of a novel targeting functionality fused to active LB-degrading amylases, called VAL-0417 and VAL-1221. We have completed in vitro proof of concept experiments and found that VAL-0417 and VAL-1221 degrade LBs. Further, in situ experiments demonstrate that they penetrate cells and they are active in cells. Strikingly, we see that intracerebroventricular (ICV) injection of VAL-0417 and VAL-1221 efficiently degrade LBs in LD mouse models, lowering total glucan levels of LD mouse brains to near WT levels. Pompe disease is a classical glycogen storage disease caused by lack of the lysosomal enzyme acid ?- glucosidase (GAA) that normally degrades glycogen. Valerion has completed pre-clinical studies with VAL- 1221 and initiated a Phase 1/2 clinical trial. This trail involves IV administration of VAL-1221. However, the current VAL-1221 formulation is not suitable for human ICV injections. Therefore, this proposal will: Specific Aims for the R61 phase of the grant (1 year) Specific Aim 1 ? Reformulate VAL-1221 for ICV delivery. A series of go/no-go studies will be performed to optimize the activity and stability of VAL-1221. We will also determine the brain biodistribution, pharmacokinetic (PK), and pharmacodynamic (PD) parameters of ICV VAL-1221. Specific Aims for the R33 phase of the grant (2 years) Specific Aim 2 ? Establish the optimal in vivo dosing strategy for ICV VAL-1221. We will perform a dose escalation study to determine the maximum tolerated dose of ICV VAL-1221, along with studies that will assess the duration and frequency of ICV VAL-1221 administration that most efficaciously improves glucan clearance from the brains of Laforin knockout mice that have extensive pathological load, i.e. LBs. We are poised to perform the preclinical research required to translate this therapy into the clinic. Additionally, VAL-1221 is a novel approach with potential beyond LD.