Claes Wahlestedt - US grants

DESCRIPTION (provided by applicant): This application is focused on the design, synthesis and evaluation of potential biological probes and treatment agents for alcohol dependence based on their actions on the nociceptin receptor (NOP receptor). We seek to identify compounds that act as partial agonists at the human NOP receptor. We will utilize a medicinal chemistry approach via de novo design and synthesis of putative NOP receptor ligands through cheminformatics efforts and by accessing compounds from the NIH's MLSCN library to generate novel compounds with high affinity, selectivity, and novel structural scaffolds. Compounds will be tested in various cell-based functional assays and in receptor binding assays. Lead compounds will be further evaluated in pharmacokinetic analyses followed by assessment of their efficacies in (1) electrophysiological assay of rat central amygdala (CeA) GABA release and (2) self-administration of alcohol in dependent rats. Current alcohol addiction pharmacotherapies have shown moderate efficacy and no clinically testable compounds targeting the NOP receptor are in existence today. Our preliminary results describe the identification of a novel and patentable NOP receptor ligand series represented by SR-2319 and SR-2039, with low nanomolar affinity and selectivity over opioid receptor family members. These compound scaffolds, and others that will be created, should prove useful for the development of additional compounds. Our current lead compound, SR-2319, like the commonly used agonist Ro64-6198, does not possess intrinsic hedonic value in rewarding brain stimulation in rats as evaluated in the intracranial self-stimulation (ICSS) paradigm. We therefore believe that targeting of the NOP receptor will not likely be associated with abuse liability. In sum, we aim to take a systematic and multi-disciplinary drug discovery strategy to identify NOP partial agonist(s) for the potential use in alcohol dependence. PUBLIC HEALTH RELEVANCE: Alcohol dependence and abuse represents a considerable health and economic burden on society with available pharmacotherapies demonstrating insufficient efficacy. Our goal is to generate a novel therapeutic entity to be used in alcohol research and with the potential of ultimately translating into the clinic as efficacious treatments for alcohol dependence and abuse.

DESCRIPTION (provided by applicant): Large-scale cDNA sequencing efforts conducted by our lab and others have provided strong evidence that, in sharp contrast to earlier understanding, much of the human genome is transcribed into non-protein-coding RNA (ncRNA). Human ncRNA transcription is extremely widespread and pervasive with potentially broad implications for neuronal function. Both short ncRNA, such as microRNA (miRNA) and long ncRNA, like natural antisense transcripts (NATs) are reported as modulators of transcription by induction of DNA methylation and chromatin remodeling. This application focuses on the role of ncRNA as epigenomic modulators of Alzheimer's disease. Our recent publication (Nature Medicine 10.1038/nm.1784,July 2008) demonstrates that ncRNA exert a pivotal role in Alzheimer's disease pathophysiology. The reports on the role of various families of ncRNA in neurological disorders highlight the fact that ncRNA-mediated epigenomic modulation of transcription is pervasive and appear particularly prominent in the nervous system. Several functions proposed for ncRNA, among them regulation of chromatin architecture and epigenetic memory, have received much attention. Importantly, modifications of chromatin structure induced by ncRNA are suggested as many histone methyl transferase (HMTase) complexes lack DNA-binding domains but possess RNA- binding motifs. Both trimethylated K4 on H3 (a mark of active transcription) and trimethylated K27 on H3 (a mark of repressed chromatin) were reported in association with ncRNAs, suggesting a scaffold model for the ncRNA in guiding chromatin modification. Here, we describe an approach to create a comprehensive epigenomic inventory of long and short ncRNA associated with Alzheimer's disease. We shall include both long and short ncRNAs by employing a NAT-specific siRNA library as well as a deep sequencing approach to create a catalog of ncRNA's involved in the pathogenesis of Alzheimer's disease. By applying Chromatin immunoprecipitation (ChIP), as well as MS2 RNA tagging and Cryogenic- immunoprecipitation, (Cryo-IP) followed by deep sequencing of RNA fractions (ChIP-Seq) and Mass-spectrometry of protein fractions, we will study RNA-chromatin, RNA-RNA and RNA- protein interactions. Further, we will validate involvement of candidate epigenomic modulators of Alzheimer's disease by studying different sets of human brain RNA derived from Alzheimer's disease patients and control individuals. The experiments proposed in this application promise to yield significant insights into epigenomic mechanisms by which gene expression is controlled. Furthermore we postulate that ncRNAs will prove to be broadly involved in the pathogenesis of Alzheimer's disease. Importantly, detailed studies on Alzheimer's disease-related ncRNAs will potentially lead to the discovery of novel therapeutic targets and/or biomarkers. PUBLIC HEALTH RELEVANCE: Alzheimer's disease is a devastating age-related neurodegenerative disorder characterized by progressive impairment of cognition and short-term memory loss. Despite considerable research efforts, researchers are still a long way from the ultimate goal of revealing clear risk factors that can help in the diagnosis, prevention and treatment of the disease. Current theories about the development of common late-onset Alzheimer's disease hinge on the premise that Alzheimer's disease arises mainly from heritable causes. However, these genetic causes are at least in part atypical (nonconventional), and we therefore argue that so-called "epigenetic/epigenomic" causes must be considered.