Jason D. Huber - US grants

DESCRIPTION: (Applicant's Abstract) Chronic pain affects nearly 70 million people a year in the United States and costs billions of dollars in medical treatments and lost productivity. To date, all investigations concerning the blood-brain barrier and opioid entry into the brain have been performed on naive, non-pained rats. The focus of my research will be to build upon already existing and proven research methodologies by introducing a pathological state (i.e. chronic pain) and then examining opioid peptide delivery across the BBB as well as determine what other BBB mechanisms are altered during pain. This study will be the first of its kind to examine the role that BBB plays in opioid transport and distribution during pain. A superior model to those used previously in assessing opioid delivery to the brain, since opioid analgesics are typically administered in an effort to relieve pain. The hypothesis of this study is that mediators released during pain affect the biochemical and molecular structure of the blood-brain barrier, resulting in alterations of opioid peptide transport into the brain. These studies will provide new information about mechanisms that may contribute to the permeability changes observed during chronic pain states. Ultimately, this grant may identify a pharmacological approach that could be used in conjunction with current therapies to alleviate pain with greater efficacy and fewer adverse side effects.

[unreadable] DESCRIPTION (provided by applicant): Age is the single greatest risk factor for stroke; yet most stroke models use younger animals. Stroke involves changes in the cerebrovasculature; yet research is predominantly focused on therapeutics that protect neurons. These incongruities in stroke research may, in part, explain the failure of successful neuroprotectants in animal studies to translate into clinically effective therapies. We argue that by not accounting for age and focusing on changes in the cerebrovasculature, the stroke community has overlooked a vast area of potential therapeutic growth. Neuropoietic cytokines play a primary role in the complex relationship between aging and chronic morbidity; yet, little attention has been focused on age- related changes in neuropoietic cytokine activity in the brain. The blood-brain barrier (BBB) is the functional element of the neurovascular unit, an extensive network comprised of endothelium, glia, pericytes, neurons, and extracellular matrix. The BBB partitions the systemic circulation from the brain parenchyma and serves to establish, maintain, and regulate discrete environments within the brain for optimal neuronal function. The proposed studies address priorities outlined in the NINDS Stroke Progress Review Group and speak to the missions of both NINDS and NIA. Our long term goal is to improve functional outcomes of people who have a stroke. Our central hypothesis states age contributes to changes in neuropoietic cytokine signaling resulting in an early, exacerbated disruption of the BBB followed by attenuated vascular recovery after ischemic stroke and reperfusion. We will test our central hypothesis with three specific aims. Specific aim 1 will determine changes in neuropoietic cytokine signaling at the neurovascular unit in aged rats following stroke/reperfusion injury. Specific Aim 2 will investigate changes in neuropoietic cytokine signaling on size and localization of BBB disruption in aged rats following stroke/reperfusion injury. Specific Aim 3 will assess changes in neuropoietic cytokine signaling on cerebral microvasculature recovery in aged rats following stroke/reperfusion injury. We expect the results from this proposal will clearly highlight that aging has profound effects on neuropoietic signaling that influences neurovascular cell-cell communication and BBB function following stroke that must be taken into account when developing and screening therapeutics to reduce morbidity and mortality. PUBLIC HEALTH RELEVANCE: In the United States, stroke is the third leading cause of death and the leading cause of disability; yet effective treatments for people suffering a stroke have not materialized. We contend that age is the single most important risk factor for stroke but most stroke research is being conducted on young animals. Furthermore, most stroke research is focused on rescuing and protecting neurons; yet, stroke is a vascular disease. This grant proposal is designed to evaluate the influence aging has on BBB function following ischemia and reperfusion. Our results will lead to a better understanding of the role age, plays in stroke etiology, progression, and recovery. [unreadable] [unreadable] [unreadable]

There is a tremendous clinical need for improved treatment of acute ischemic stroke. Currently, recombinant tissue plasminogen activator (tPA) is the only FDA approved drug for treatment of acute ischemic stroke. However, less than 5% of people suffering an ischemic stroke receive tPA due to increased risk of secondary cerebral hemorrhage and edema formation. Thus, an unmet need exists to develop novel therapeutics that work in combination with tPA to improve stroke outcome, reduce secondary complications, and extend the time window for administering tPA. Bryostatin-1, an ultrapotent PKC modulator, may provide substantial benefit for treatment of acute ischemic stroke. The long-term goal of our research is to identify and develop therapeutics that markedly improve the safety profile of tPA so that more victims of ischemic stroke are eligible for thrombolysis. The objective of this proposal is to determine if tPA time window can be extended in aged rats co- administered bryostatin-1 with tPA. The central hypothesis is that PKC? activation by administration of bryostatin-1 during the acute phase of ischemic cerebral infarction attenuates cerebral endothelium dysfunction; thus, decreasing the degree of injury & increasing the window, in which reperfusion can be safely accomplished. Rationale is that using two separate models of neurological injury (MCAO & mild traumatic brain injury), administration of bryostatin-1 reduced hemispheric swelling & BBB permeability with improved survival & functional recovery. Using our clinically relevant ischemic stroke model, we will use biochemical, neuropathological, and behavioral measures, to test our central hypothesis and accomplish the objective of this proposal, as described in these two specific aims: (1) Identify optimal dose of bryostatin-1 & validate PKC? as a therapeutic target & (2) identify therapeutic target of bryostatin-1 that improves cerebrovascular function post- MCAO. Specific aim 1 tests the working hypothesis that co-administration of bryostatin-1 with tPA at 6 h after MCAO will selectively activate PKCe in neurons & cerebral microvessels & it will be lower doses of bryostatin-1 (10-30 mcg/m2) that produce the most efficacious stroke outcome. Specific aim 2 test the working hyothesis that co-administration of bryostatin-1 with tPA at 6 h after MCAO reduces cerebral swelling, mitigates hemorrhagic transformation & improves stroke outcome by selective PKC? activation in cerebral endothelial cells attenuating BBB dysfunction in the infarcted hemisphere. Due to the prevalence & debilitating effects of ischemic stroke, the need for better therapeutic strategies cannot be overstated. Unfortunately, the ability to translate promising preclinical findings into effective drugs that clinically mitigate post-stroke brain damage has, to date, failed. This proposal will determine if co-administration of bryostatin-1 with tPA improves stroke outcome & extends the tPA time window following acute ischemic stroke. Results from this proposal have the translational potential to vastly improve the way ischemic stroke is treated.