2012 — 2015 |
Kavelaars, Annemieke |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
A Novel Molecular Switch Regulating Transition From Acute to Chronic Pain. @ University of Tx Md Anderson Can Ctr
DESCRIPTION (provided by applicant): Chronic pain causes debilitation and suffering in millions of Americans. Treatments to provide relief from this chronic pain are often ineffective. A critical and rate-limiting step for developing new treatments is that the underlying biological cause for the transition from acute to chronic pain is poorly understood. This research application is targeted directly at filling this void. We recently discovered that G protein-coupled receptor kinase 2 (GRK2) is key to preventing transition to chronic hyperalgesia. Chronic inflammation causes a decrease in GRK2 in pain transmitting neurons (nociceptors) that we mimicked in a mouse model using Cre-Lox technology. Using this model, we have now demonstrated that low nociceptor GRK2 markedly prolongs thermal hyperalgesia induced by the prototypic inflammatory mediator prostaglandin E2 (PGE2) without affecting baseline sensitivity. This project aims at determining the molecular pathways that underlie the transition to chronic pain that occurs when nociceptor GRK2 is low and understanding how chronic inflammation reduces GRK2 in nociceptors. Our hypothesis is that an inflammation-induced reduction in nociceptor GRK2 switches signaling in response to cAMP-inducing mediators like PGE2 from protein kinase A towards the cAMP target known as exchange protein directly activated by cAMP (Epac) and its downstream targets leadin to transition to chronic pain. To test our hypothesis we will answer four specific questions: 1. What is the contribution of nociceptor GRK2 to mechanical hyperalgesia? 2. How do GRK2 and Epac1 interact to regulate Epac signaling to its downstream effectors? 3. When and how does inflammation reduce GRK2 and increase Epac1 in nociceptors? and 4. Can we generate proof of principle that targeting GRK2/Epac prevents transition to chronic pain? In aim 1, we will use an in vivo approach with SNS-GRK2 mice that have low nociceptor GRK2. In aim 2, in vitro approaches using GRK2 deletion mutants, a kinase dead GRK2 mutant, kinase assays and co-immuno-precipitations will be used. In aim 3, we will use immuno-fluorescence and qPCR analysis of nociceptor GRK2/Epac in response to inflammation. In aim 4, we will use a classic genetic approach to develop and use novel mouse models with nociceptor specific deletion of Epac1 and overexpression of GRK2. The proposed research is innovative for three major reasons: (a) This is the first time GRK2 has been found to function as an endogenous inhibitor of Epac activation; (b) We will directly test our hypothesis that the newly discovered GRK2/Epac interface functions as an intracellular molecular switch regulating hyperalgesic signaling and thereby the transition to chronic pain; (c) Identifying the downstream GRK2/Epac interface to combat chronic pain represents a completely novel approach that avoids the disadvantages of targeting upstream receptors or mediators. This contribution is significant because it is the first step in a continuum of research that is very likely to lead to development of novel pharmacologic strategies that specifically target the newly identified GRK2/Epac interface to prevent chronic pain.
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0.954 |
2012 — 2015 |
Dantzer, Robert Kavelaars, Annemieke Kelley, Keith W (co-PI) [⬀] |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
A Novel Neuroimmune Risk Factor For Comorbid Depression and Chronic Pain @ University of Tx Md Anderson Can Ctr
DESCRIPTION (provided by applicant): The present application aims at using neuroimmune approaches to understand the neurobiological basis of behavior. The objective is to study how dysregulated interactions between the nervous and immune systems contribute to comorbidity of depression and pain. Depressive disorders and chronic pain represent two major health burdens in the Western world. Chronic pain predisposes to depression and vice versa, and 30-60% of the cases suffer from both depression and chronic pain. The broad question we seek to answer using a neuroimmune approach is: Why is chronic pain a risk factor for depression, and vice versa? Peripheral inflammation causes sickness behavior that can culminate into depressive behavior when the tryptophan metabolizing enzyme 2,3 indoleamine dioxygenase (IDO) is upregulated. We recently made the exciting discovery that an intracellular protein known as G protein coupled receptor kinase 2 (GRK2) possesses anti- inflammatory properties and acts as a molecular switch that regulates transition from acute to chronic pain. Our newest preliminary data indicate that low GRK2 enhances IDO expression by microglia in vitro. This proposal will test the completely novel concept that GRK2 is a critical molecule that explains the shared risk for developing depression and chronic pain. We have shown that chronic neuropathic pain or inflammation significantly reduces GRK2 in microglia from rodents. This finding is clinically important because low GRK2 in microglia is sufficient to transform transient inflammatory pain into chronic pain. We also showed that low GRK2 augments pro-inflammatory cytokine production and increases activation of p38 in vivo and in vitro. Moreover, we have preliminary data that p38 activity regulates IDO expression, which is key to development of inflammation-associated depressive-like behavior. We hypothesize that the reduction in microglial GRK2 caused by chronic neuropathic pain increases microglial p38 activity, pro-inflammatory cytokine production and IDO expression, thereby acting as risk factor for prolonged depressive-like and pain behaviors. To test this hypothesis, we will answer the following specific questions: 1. Is development of neuropathic pain and depressive-like behavior temporally related to the inflammation-induced reduction in GRK2 and the increase in IDO in CNS microglia/mF? 2. Is low GRK2 a risk factor for development of depressive-like behaviors and what is the mechanism? We will use mice with low GRK2 in microglia that we have generated using Cre-Lox technology. 3. Are comorbid depression and chronic pain both prevented by treatments that interfere with the loop of reduced GRK2, increase in p38 activity and upregulation of IDO? Collectively, these innovative experiments will identify low GRK2 as a completely novel risk factor for development of comorbid depression and chronic pain via a p38/cytokine/IDO-dependent pathway. Identification of these new molecular mechanisms underlying comorbid depression and pain is needed for effective development of novel prevention and therapeutic strategies.
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0.954 |
2016 — 2020 |
Heijnen, Cobi J Kavelaars, Annemieke |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Mesenchymal Stem Cells to Repair Chemobrain @ University of Tx Md Anderson Can Ctr
PROJECT SUMMARY Chemotherapy-induced cognitive deficit (?chemobrain?) is a major side effect of cancer treatment that fre- quently persists long into survivorship. There are no FDA-approved drugs for prevention or treatment of che- mobrain, and the underlying mechanisms are poorly understood. This application aims at filling this void and responds to provocative question #9: What are the molecular and/or cellular mechanisms that un- derlie the development of cancer therapy-induced severe adverse sequelae? Our previous work in models of ischemic brain damage demonstrated that nasally applied mesenchymal stem cells migrate into the brain to restore cognitive and sensorimotor dysfunction, by promoting endogenous repair mechanisms leading to restoration of brain structure and by suppression of neuro-inflammation. Our preliminary data show that cisplatin induces cognitive deficits in mice that are associated with decreased neurogenesis, abnormalities in white matter organization and dendritic spine integrity, and impaired mito- chondrial respiration. Preliminary data indicate that mesenchymal stem cells (MSC) administered intranasally travel into the brain, restore the cognitive deficits and normalize mitochondrial function. Preliminary in vitro data indicates that MSC transfer healthy mitochondria to neurons damaged by cisplatin. Our working hypothesis is that cisplatin induces cognitive deficits by causing persistent mitochondrial damage leading to neuroinflammation, stem cell depletion, abnormalities in white matter organization and dendritic spine integrity, and impaired synaptic connectivity. We propose that nasally administered MSC re- verse CICI by restoring mitochondrial function and suppressing neuroinflammation. To test our hypothesis we will pursue the following Specific Aims: Aim 1: Treat CICI by intranasal administration of MSCs; Aim 2: Determine whether nasally administered MSCs migrate into the brain to promote endogenous repair mecha- nisms; and Aim 3: Determine the mechanisms underlying the effect of cisplatin and MSC on the brain. This study is innovative because: a) we will be the first to fully analyze CICI in the mouse at the neuroim- aging, cellular, mitochondrial and inflammatory levels; b) the potential to restore CICI by nasal administration of MSC has not been tested; c) the hypothesis that MSC transfer mitochondrial to damaged neurons in vivo has not been tested; c) successful completion of this study will identify key molecular mechanisms underlying chemobrain; and d) we will provide proof of principle that chemobrain can be repaired. This project is significant because chemobrain is a common side effect of cancer treatment that often per- sists into survivorship and reduces quality of life. We have already performed extensive safety studies in mice treated with MSC for ischemic brain damage. Successful completion of this project will provide the first step toward a treatment for brain damage and associated functional impairments caused by chemotherapy for tu- mors outside the nervous system or by other cancer treatments, including radiation therapy for brain tumors.
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0.954 |
2016 — 2020 |
Dantzer, Robert Heijnen, Cobi J Kavelaars, Annemieke |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Neuroimmune Mechanisms of Recovery From Comorbid Depression and Chronic Pain @ University of Tx Md Anderson Can Ctr
SUMMARY Depression and chronic pain frequently co-occur and are difficult to treat. In the first award period, we identified mechanisms common to both depression and pain as well as mechanisms specific to depression. We showed that inflammatory activity in the spinal cord is at the origin of both pain and depression in a mouse model of chronic neuropathic pain in response to nerve injury. However, depression additionally requires in- flammation-induced activation of the tryptophan metabolizing enzyme indoleamine 2,3 dioxygenase (IDO1). In this renewal application, we propose to change our focus from the mechanisms underlying devel- opment of depression and chronic pain to the endogenous resolution mechanism that normally prevents transition to these maladaptive, long-lasting consequences of inflammation. We have obtained exciting new findings identifying a key role for CD8 T cells in the resolution of depression and pain. Our preliminary data indicate that T cells and endogenous peripheral monocytes that produce the cyto- kine interleukin (IL)-10 are required for resolution of inflammation-induced pain and depression. Mice that genetically lack T cells develop prolonged pain and depression in two different models of peripheral inflamma- tion. Adoptive transfer of T cells to these mice normalizes resolution of pain and depression without altering the course of peripheral inflammation. The prolonged depression in T cell-deficient mice versus control mice is associated with persistent elevation of IDO1 and lack of IL-10 production in the brain. Our overall hypothesis is that CD8 T cells promote resolution of depression and pain by inducing IL-10 production by monocytes/macrophages. This leads to the downregulation of glial activation in the central nerv- ous system. In addition, we propose that CD8 T cells that have been educated in vivo in either an antigen-spe- cific or a non?antigen-specific way will be more efficient than T cells from naïve mice will be in promoting res- olution of inflammation-induced pain and depression. We will pursue 3 specific aims to test this set of hypotheses: Aim 1: Examine the role of T cells in the resolution of depression-like behavior and pain; Aim 2: Investigate the contribution, source, and target cell of endogenous IL-10 in promoting resolution of depression and pain; Aim 3: Assess whether T cells are educated in vivo to promote resolution of depression and pain. Our proposal is innovative because the concept that neuroimmune T cell-dependent mechanisms are re- quired for recovery from depression pain opens a totally novel perspective on the treatment of comorbid pain and depression. This project is significant because of the high prevalence of comorbid depression and chronic pain and the lack of effective treatment. If successful, our project will unravel unexplored endogenous path- ways governing resolution of depression and pain, and thereby allow the development of novel strategies for treatment, including ex vivo T cell education or vaccination strategies.
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0.954 |
2018 — 2019 |
Galko, Michael J [⬀] Kavelaars, Annemieke |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
An Exploratory Proposal to Move Select Drosophila Nociception Screen Hits Into Mouse Models @ University of Tx Md Anderson Can Ctr
PROJECT SUMMARY/ABSTRACT Pain and pain sensitization are devastating side effects of tissue injury, cancer treatment, and certain diseases like diabetes. Treating pain effectively is an enormous clinical obstacle for many injuries and disease states. Pain research leaders have argued that new models in which novel conserved gene targets can be efficiently identified are urgently needed. Even more essential is the translation of new conserved targets functionally identified in these new and simple models to more clinically relevant vertebrate models. Our long-term goal is to identify novel pain/pain sensitization regulators with high potential for clinical translation. Over the last ten years my laboratory has performed a number of genetic screens in the fruit fly Drosophila, by combining unique tissue damage and pain assays. These screens have identified highly conserved regulators of pain biology (in particular acute and chronic pain sensitization following tissue damage) whose roles in regulating pain were not previously appreciated from work in other models. The two most promising screen hits as defined by conservation, robustness and uniqueness of their Drosophila phenotype, and novelty to pain biology, are Smoothened, the signal transducer of the Hh signaling pathway, and the Insulin receptor. In fly larvae, both genes are required in peripheral nociceptive sensory neurons? Smoothened to regulate acute thermal pain sensitization and the Insulin receptor (InR) to regulate the cessation of acute sensitization. InR is particularly interesting as the neuron-specific role in regulating the transition from acute to chronic sensitization may provide an entirely new way of looking at the pain associated with diabetes. Our goal in this exploratory R21 proposal is necessary and urgent. For both Smoothened and the Insulin Receptor we propose to perform parallel experiment(s) in mice to those that we have already performed in flies: we will conditionally knock these genes out in pain-sensing sensory neurons and assess baseline, acute, and chronic pain phenotypes in two standard assays. This is necessary because this type of forward translation of Drosophila-based results, though standard and useful in developmental biology and innate immunity, has not been previously attempted in any systematic way in the pain field. It is urgent because successful translation (meaning the genes do actually regulate pain biology in some way in mice) could establish a veritable pipeline of new conserved pain gene targets for testing in vertebrate models. This is especially true as we have many other conserved targets that have been identified in our screens. The results could be both scientifically compelling- providing new insight into conserved regulation of pain responses. They could also be clinically useful- pointing the way to new druggable conserved targets that have been difficult to identify systematically in other complementary experimental systems. The importance of pain-sensing and sensitizing mechanisms to the animal, reflected in the high evolutionary conservation of these mechanisms, suggest to us that this approach is likely to work.
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0.954 |
2018 — 2021 |
Heijnen, Cobi J Kavelaars, Annemieke |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Pq12 Targeting Hdac6 For Chemotherapy-Induced Neuropathy and Chemobrain @ University of Tx Md Anderson Can Ctr
SUMMARY Chemotherapy-induced peripheral neuropathy (CIPN) and chemotherapy-induced cognitive impairment (CICI) are major side effects of cancer treatment that frequently persist long into survivorship. No drugs have been approved by the US Food and Drug Administration to prevent and/or adequately manage CIPN and CICI. This application aims at filling this void. A concern when designing drugs to manage CIPN and CICI is that they should not impair tumor control. Ideally, agents to control these neurotoxicities should also enhance tumor control. Recent findings indicate that inhibitors of histone deacetylase 6 (HDAC6) meet these goals. HDAC6 de-acetylates non-histone cytosolic proteins like tubulin without inducing epigenetic changes. Recent preclinical and clinical data show promise for HDAC6 inhibitors to improve tumor control. We recently showed that HDAC6 inhibition fully reverses established CIPN in cisplatin-treated mice. This was associated with restoration of mitochondrial health in sensory neurons. Preliminary data indicate that co- administration of HDAC6 inhibitors protect against CIPN by preventing mitochondrial damage. Additional preliminary data indicate that HDAC6 inhibition also reverses established CICI and associated brain mitochondrial damage. Our hypothesis is that HDAC6 inhibition prevents and reverses CIPN and CICI in mice with or without tumors by targeting mitochondrial health, oxidative stress, and downstream neuroimmune pathways. We will test our hypothesis in 3 specific aims: Aim1: Determine the capacity of HDAC6 inhibitors to prevent CIPN in mice with or without tumors. Aim 2: Determine the effect of HDAC6 inhibition on established CIPN. Aim 3: Determine whether the beneficial effects of HDAC6 inhibition extend to CICI. In aims 1 and 3, we will investigate the effect of HDAC6 inhibitors on tumor control and ensure that HDAC6 inhibitors also prevent CIPN and CICI in the presence of a tumor. This study is innovative because we propose to target HDAC6 activity in neurons to control neurotoxicities while at the same time enhancing cancer control. The expected outcome is significant because it will identify HDAC6 inhibition as a realistic novel approach to control CIPN and CICI. This will increase the quality of life of millions of cancer patients and survivors. Clinical trials to examine the effect of HDAC6 inhibitors on tumor control are already underway, and therefore the expected results of this project should rapidly convince clinicians to examine the value of HDAC6 inhibitors for management of both CIPN and CICI. Identification of HDAC6 inhibitors as drugs that can be used after completion of chemotherapy to completely resolve established CIPN and CICI will be of great benefit for cancer survivors suffering every day from these persistent neurotoxicities.
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0.954 |