Owen M. Woodward, PhD - US grants

DESCRIPTION (provided by applicant): Common rhythmic motor behaviors such as walking, chewing, and breathing are controlled by neural circuits and central pattern generators. Recent studies show single neural circuits can be reconfigured to control two totally different motor behaviors. The marine mollusc Tritonia diomedea possesses a well described rhythmic motor pattern, the escape swim response, and evidence suggests the escape swim control circuit may also control the non-rhythmic/non- muscular crawling behavior. Tritonia diomedea's non- muscular crawling is cilia based and therefore offers the additional opportunity of studying the mechanisms for ciliary control and coordination. This proposal represents the beginnings of a project focusing on the crawling motor system, specifically: a characterization of the neural mechanism responsible for coordinating the motor output / cilia beating (Aim I) and the cellular machinery of cilia beating control (Aim II). The completion of this project will produce a detailed description of how a nervous system can control cilia behavior, the first step of understanding the entire crawling motor system. Cilia lining brain ventricles, airways, and oviducts may be coordinated under nervous control and Tritonia offers an excellent opportunity to discover how. This project may also contribute to the understanding and treatment of motor system disorders as well as demonstrate how the CNS may control non-muscular motor behaviors.

Uric acid (UA) is a terminal metabolite of the purine metabolic pathway in humans. Excess UA, the clinical disorder hyperuricemia, affects 43 million Americans causing gout and increasing risk for hypertension, stroke, metabolic syndrome, and chronic kidney disease. A genetic and physiological approach led to our identification of the multidrug transporter ABCG2 as a high capacity UA efflux transporter and that common ABCG2 variants make the largest genetic contribution to increased UA levels and gout risk. Although the genetic role of ABCG2 in hyperuricemia and gout risk is now well established, we know little of the physiological role of ABCG2 as a renal UA transporter. The process of UA homeostasis is by necessity a dynamic process as diet and metabolism produce highly variable UA loads. Thus, the overarching goal of this proposal is to develop a mechanistic explanation of how ABCG2 mediated renal UA excretion is physiologically regulated, and how dysfunction of the process leads to hyperuricemia and human disease. The AIMs of our proposal will address the following three questions: 1) Is ABCG2 physiologically regulated in vivo and a critical component of UA homeostasis? 2) What role does phosphorylation play in regulating ABCG2 and renal UA excretion? and 3) How does the common ABCG2 gout mutation Q141K alter ABCG2 regulation and the physiology of renal UA excretion? This work will provide a new understanding of the molecular mechanisms of urate homeostasis and illuminate both the consequences of dysregulated hyperuricemia on human health, and novel therapeutic targets for treatment.

PROJECT SUMMARY The Maryland Polycystic Kidney Disease Research and Translation Core Center (MPKD-RTCC) Cell Culture and Engineering Core (CCEC) will accelerate progress in PKD research by addressing a major unmet need for well-defined, reliable in vitro cell PKD models with proper controls. With this overarching goal in mind, CCEC developed new in vitro cell and organoid models that we hope will become the ?gold-standards? of the field. The CCEC is committed to helping investigators find ideal solutions for all their individual in vitro research needs whether it involves mechanistic exploration, human PKD cell validation studies, or therapeutic screening. To best serve the current and expected future demands of the diverse PKD workforce in academia, government, and industry, the CCEC will provide murine cell models of ADPKD, provide engineered inner medullary collecting duct (IMCD3) cell lines expressing custom PKD1 and PKD2 mutations, provide human kidney ADPKD cells and specimens, provide a cutting edge cystogenesis assay using three-dimensional organoid system, provide high through-put, three- dimensional cyst expansion assay, and provide consultation services to make sure the PKD community can fully utilize the CCEC resources.