PROJECT SUMMARY This project is a continuation and further development of a previous INIA project, which was based on studies showing ethanol-induced changes in brain neuroimmune gene expression in animal models and humans. Those data suggested that ethanol dysregulates proinflammatory, Toll-like receptor (TLR) signaling in the brain. During the previous period of funding, we found that pharmacological or genetic manipulation of molecules that signal through the myeloid differentiation primary response gene 88 (MyD88) alters ethanol intake and preference. The proposed renewal has three Specific Aims. Specific Aim 1 seeks to repurpose three existing FDA-approved drugs with proven anti-inflammatory activity: apremilast (a phosphodiesterase-4 inhibitor recently approved for treating psoriasis), sulfasalazine (an inhibitor of IKKβ used in the treatment of inflammatory bowel disease), and gemfibrozil (a PPARα activator used in the treatment of hyperlipidemia). These drugs will be tested for their effectiveness in reducing ethanol intake and altering other ethanol- dependent behaviors in mice. Specific Aim 2 will explore another branch of TLR inflammatory signaling that depends on signaling via the TIR-domain-containing adapter-inducing interferon-β (TRIF) protein. This aim will examine the role of brain regional and cell-specific knockdown of TRIF-dependent signaling proteins on ethanol intake using lentiviral-mediated RNA interference in collaboration with the Lasek project. Specific Aim 3 serves a collaborative function to provide behavioral testing of new drugs and candidate genes for other INIA projects. The Mayfield project will analyze gene expression networks to predict drugs that will normalize the network, and we will test these drugs for their ability to reduce ethanol consumption in mice. The Hitzemann and Mayfield projects will elect candidate long non-coding RNAs based on transcriptome analyses of high drinking-in-the-dark (HDID) mouse lines and of rhesus macaques chronically exposed to ethanol (in collaboration with INIA-Stress) and human postmortem brain samples. The Homanics project will generate mutant mice for the candidate long non-coding RNAs, and we will perform behavioral testing with these mice. We will also continue to provide mutant mice for the Roberto project and provide Crh-Cre rats for the Pfefferbaum/Zahr project. We anticipate that other INIA projects will identify additional drugs or targets that require behavioral testing, which we will carry out as part of this collaborative function.