Funded Projects

Multi-protein complexes have emerged as a mechanism for spatiotemporal specificity and efficiency in the function and regulation of cellular signals. Many ion channels are clustered either with the receptors that modulate them or with other ion channels whose activities are linked. Often, the clustering is mediated by scaffolding proteins, such as AKAP79/150. We will probe complexes containing AKAP79/150 and three different channels critical to nervous function: KCNQ/Kv7, TRPV1, and CaV1.2. We will use"super-resolution" STORM imaging of primary sensory neurons and heterologously expressed tissue-culture cells, in which individual complexes can be visualized at 10–20 nm resolution with visible light. We hypothesize that AKAP79/150 brings several of these channels together to enable functional coupling, which we will examine by patch-clamp electrophysiology of the neurons. Since all three of these channels bind to AKAP79/150, we hypothesize that they co-assemble into complexes in neurons and that they are dynamically regulated by other cellular signals.

Data suggest that members of minority groups are more likely to develop chronic pain and to have greater pain burden. We will identify a set of promising intervention targets for reducing or eliminating racial/ethnic pain disparities. We will interview adult survivors of serious physical injury, comprised of roughly equal proportions of African-Americans (AA), Latinos, and non-Latino Whites (NLW), and examine their medical records for information on injury severity and medication use in-hospital. Our aims are to determine whether: 1) AA and Latino physical injury survivors experience more severe pain relative to NLW; 2) AA and Latino injury survivors experience greater pain burden relative to NLW counterparts; 3) differences in pain severity burden are linked to a set of target candidates for interventions; and (4) pain outcomes in at-risk minority groups can be linked to a set of target candidates for group-tailored interventions to reduce pain severity and pain burden.

An International Cooperative Biodiversity Group with an interdisciplinary leadership team of physicians, pharmacologists, evolutionary biologists, and chemists will discover and develop therapeutic agents produced by Brazilian symbiotic bacteria. The team will target three therapeutic areas: 1) infectious fungal pathogens, 2) Chagas disease and leishmaniasis, and 3) cancers of the blood. All three areas represent major threats to human health that need to be addressed with new therapeutic agents. Internationally, invasive fungal diseases kill more people than malaria or TB, while Chagas disease imposes a special burden on Brazil, killing as many Brazilians as TB. Leishmaniasis has now passed Chagas disease in the Brazilian population. Despite major improvements in cancer chemotherapy, cancer is projected to result in 8 million deaths internationally this year (13% of all deaths, WHO) and an estimated 13 million per year by 2030.

The Philippine Mollusk Symbiont International Cooperative Biodiversity Group harnesses the vast biodiversity of the Philippines to discover new drugs to treat bacterial infections, parasitic infections, pain, and other neurological conditions and cancer, all of which are serious health problems in both the Philippines and the United States. The Republic of the Philippines represents a unique nexus of exceptional biodiversity, dense human population with pressing societal needs, consequent urgent need for conservation, and government commitment to education and technology to harness national human and natural resources for a sustainable future. Mollusks are one of the most diverse groups of marine animals, and their associated bacteria represent an unexplored trove of chemical diversity. Researchers will use an increasing understanding of the interactions between mollusk symbionts and their hosts to discover the most novel and useful molecules. The project will document and describe Philippine mollusk biodiversity and support training and infrastructure that provide the foundation for conservation of Philippine biodiversity.

The goal of this project is to generate data and reagents that help uncover critical functions of the poorly characterized members of ion channels. It focuses on co-perturbation of ion channel genes and their interacting genetic components as opposed to singly altering ion channel genes in mouse models. This approach will validate our proteomics approaches in the most definitive manner: in vivo. We see in vivo exploration as an essential step to evaluate ion channel function. Our major aims include mapping ion channel interactions and complexes using a high-throughput proteomics platform at UCSF. These data will be interrogated using integrative approaches established by the Monarch Initiative, where biochemical interactions will be validated and prioritized for further study. Another major aim is function-centric: We use mouse models for elucidation of human disease mechanisms, where we embrace a genetic interaction scheme to uncover ion channel redundancy and polygenic effects.

The primary objective of this project is to de-implement the use of opioid analgesics for the management of postoperative pain following dental extractions and to implement effective alternative pain management. We propose a cluster-randomized trial designin which dental practitioners are randomly assigned to one of three conditions: 1) standard practice as a control condition; 2) a clinical decision support (CDS) tool that will extract patient history and interface with the state prescription drug monitoring program to provide personalized recommendations for analgesic prescribing and offer language for discussing non-opioid pain management; 3) an enhanced version of the CDS (CDS-E) that will also include information regarding optimal, evidence-based non-opioid pain management delivered to the patient both before and following the dental extraction visit. We will examine opioid and non-opioid prescribing data from the electronic health record across study arms as well as other provider- and patient-focused outcomes using mixed methods.

Persistent pain states arising from inflammatory conditions, such as in arthritis, diabetes, HIV, and chemotherapy, exhibit a common feature in the release of damage-associated molecular pattern molecules, which can activate toll-like receptor-4 (TLR4). Previous studies suggest that TLR4 is critical in mediating the transition from acute to persistent pain. TLR4 as well as other inflammatory receptors localize to lipid raft microdomains on the plasma membrane. We have found that the secreted apoA-I binding protein (AIBP) accelerates cholesterol removal, disrupts lipid rafts, prevents TLR4 dimerization, and inhibits microglia inflammatory responses. We propose that AIBP targets cholesterol removal to lipid rafts harboring activated TLR4. The aims of this proposal are to: 1) determine whether AIBP targets lipid rafts harboring activated TLR4; 2) test whether AIBP reduces glial activation and neuroinflammation in mouse models of neuropathic pain; and 3) identify the origin and function of endogenous AIBP in the spinal cord.

TWIK-related spinal cord K+ (TRESK) channel is abundantly expressed in all primary afferent neurons (PANs) in trigeminal ganglion (TG) and dorsal root ganglion (DRG), mediating background K+ currents and controlling the excitability of PANs. TRESK mutations cause migraine headache but not body pain in humans, suggesting that TG neurons are more vulnerable to TRESK dysfunctions. TRESK knock out (KO) mice exhibit more robust behavioral responses than wild-type controls in mouse models of trigeminal pain, especially headache. We will investigate the mechanisms through which TRESK dysfunction differentially affects TG and DRG neurons. Based on our preliminary finding that changes of endogenous TRESK activity correlate with changes of the excitability of TG neurons during estrous cycles in female mice, we will examine whether estrogen increases migraine susceptibility in women through inhibition of TRESK activity in TG neurons. We will test the hypothesis that frequent migraine attacks reduce TG TRESK currents.

Wound care procedures (WCPs), such as dressing changes, cause moderate to severe pain in 74% of patients, nearly half of whom experience severe pain. Mainstay recommendations to prevent pain during WCPs have focused on either administration of preventive and procedural analgesia or use of expensive, non-adherent dressings. However, it is unclear which patients to target for analgesia or expensive dressings, leading to their inappropriate over- or underuse. To achieve the aims of the study, a comprehensive set of wound, patient, and biological factors will be measured concurrently with pain during a dressing change among a sample of 450 inpatients with open wounds. A predictive model will be developed and biological mechanisms will be examined using logistic regression. The proposed study has the potential to make significant contributions because clinicians will be able to target those patients requiring preventive pain control, thereby eliminating the spiraling impact of painful procedures on nociceptor sensitization.

We discovered a class of non-opioid modulators of the T-type Cav3.2 channel that could treat neuropathic pain. In vivo pharmacokinetic and pharmacodynamic studies and preliminary toxicological studies identified AFA-279 and other candidates, which did not produce observable side-effects and showed greater analgesic effects than other neuropathic pain medications in rodent models. The goal of this proposed project is to submit the IND application on our Cav3.2 modulator to the Food and Drug Administration (FDA). We will produce AFA-279 under Good Manufacturing Practice (GMP)–like conditions using chemical manufacturing controls for Good Laboratory Practice (GLP) nonclinical toxicity studies and GMP clinical batch future Phase 1 clinical trials, complete toxicological and safety studies to establish the safety profile of AFA-279, prepare and submit the IND application, and then initiate early clinical trials. Our ultimate goal is to deliver a safer, more effective, non-opioid Cav3.2 channel modulator to patients suffering from neuropathic pain.

Postoperative ileus (POI) following gastrointestinal (GI) surgery leads to significant patient morbidity and prolonged hospitalizations. Recent studies have demonstrated that intestinal manipulation and surgical trauma activate inflammatory macrophages (M?) and release inflammatory mediators such as nitric oxide (NO) to inhibit intestinal smooth muscle cells in POI. Intestinal M? are a highly heterogeneous and dynamic population in the innate immune system. Preliminary studies show that transient receptor potential vanilloid 4 (TRPV4) channel, a molecular sensor of tissue damage and inflammation, is exclusively expressed by the F4/80+/CD206+ intestinal anti-inflammatory M2 M?. Activation of TRPV4 produces an intestinal contractile response and improves GI transit in a mouse model of POI. The current proposal aims to elucidate the cellular and molecular mechanisms underlying the activation of TRPV4 in the intestinal M2 M?.

Sickle cell disease (SCD) is an inherited hematologic disorder accompanied by severe pain, inflammation, and vascular injury. We propose that nociceptor activation by ongoing hypoxia/reperfusion (H/R) injury leads to the release of neuropeptides by sensory nerves in the skin, stimulating vascular insult and mast cell activation in SCD. In turn, mast cell tryptase activates protease-activated receptor 2 on sensory nerve endings, resulting in exaggerated neuroinflammation, vascular injury, and central sensitization. Our general hypothesis is that neurogenic inflammation contributes to pain in SCD and that cannabinoids provide analgesia by disrupting neurogenic inflammation and nociceptor sensitization. We also hypothesize that EEG and functional MRI can be used to optimize analgesic treatments in SCD. We propose to use transgenic sickle mice, and individual cells involved in evoking pain, to perform this translational study. A proof of principle study in humans will examine the effect of cannabis on pain in sickle patients.