Neuropathic pain is a debilitating public health concern for which novel non-narcotic therapeutic targets are desperately needed. Using unbiased transcriptomic screening of the dorsal horn spinal cord after nerve injury we have identified that Gpr183 (Epstein-Barr virus-induced gene 2) is upregulated after chronic constriction injury (CCI) in rats. GPR183 is a chemotactic receptor known for its role in the maturation of B cells, and the endogenous ligand is the oxysterol 7a,25-dihydroxycholesterol (7a,25-OHC). The role of GPR183 in the central nervous system is not well characterized, and its role in pain is unknown. The profile of commercially available probes for GPR183 limits their use as pharmacological tools to dissect the roles of this receptor in pathophysiological settings. Using in silico modeling, we have screened a library of 5 million compounds to identify several novel small-molecule antagonists of GPR183 with nanomolar potency. These compounds are able to antagonize 7a,25-OHC-induced calcium mobilization in vitro with IC 50 values below 50 nM. In vivo intrathecal injections of these antagonists during peak pain after CCI surgery reversed allodynia in male and female mice. Acute intrathecal injection of the GPR183 ligand 7a,25-OHC in naïve mice induced dosedependent allodynia. Importantly, this effect was blocked using our novel GPR183 antagonists, suggesting spinal GPR183 activation as pronociceptive. These studies are the first to reveal a role for GPR183 in neuropathic pain and identify this receptor as a potential target for therapeutic intervention. SIGNIFICANCE STATEMENTWe have identified several novel GPR183 antagonists with nanomolar potency. Using these antagonists, we have demonstrated that GPR183 signaling in the spinal cord is pronociceptive. These studies are the first to reveal a role for GPR183 in neuropathic pain and identify it as a potential target for therapeutic intervention.These studies were supported by the Saint Louis University start-up funds of Dr.

Many clinical studies and epidemiological investigations have clearly demonstrated that women are twice as likely to develop cholesterol gallstones as men, and oral contraceptives and other estrogen therapies dramatically increase that risk. Further, animal studies have revealed that estrogen promotes cholesterol gallstone formation through the estrogen receptor (ER) α, but not ERβ, pathway. More importantly, some genetic and pathophysiological studies have found that G protein-coupled estrogen receptor (GPER) 1 is a new gallstone gene, Lith18, on chromosome 5 in mice and produces additional lithogenic actions, working independently of ERα, to markedly increase cholelithogenesis in female mice. Based on computational modeling of GPER, a novel series of GPER-selective antagonists were designed, synthesized, and subsequently assessed for their therapeutic effects via calcium mobilization, cAMP, and ERα and ERβ fluorescence polarization binding assays. From this series of compounds, one new compound, 2-cyclohexyl-4-isopropyl-N-(4-methoxybenzyl)aniline (CIMBA), exhibits superior antagonism and selectivity exclusively for GPER. Furthermore, CIMBA reduces the formation of 17β-estradiol-induced gallstones in a dose-dependent manner in ovariectomized mice fed a lithogenic diet for 8 weeks. At 32 μg/day/kg CIMBA, no gallstones are found, even in ovariectomized ERα (−/−) mice treated with 6 μg/day 17β-estradiol and fed the lithogenic diet for 8 weeks. In conclusion, CIMBA treatment protects against the formation of estrogen-induced cholesterol gallstones by inhibiting the GPER signaling pathway in female mice. CIMBA may thus be a new agent for effectively treating cholesterol gallstone disease in women.­

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This work explores the interface between 3D-printing, material sciences, and microfluidics with electrochemical detection in an undergraduate laboratory. This work includes a module for the characterization and electrochemical analysis of microelectrodes that spans 4 weeks (3 h per week). Laboratory exercises include the fabrication of a 3D-printed device, examination of 3D-printing techniques, scanning electron microscopy (SEM), and electrochemistry. This interdisciplinary curricula exposed students to the process of designing a functioning microfluidic device. Students began by designing the microfluidic chip with AutoDesk Inventor. To gain a better understanding of the microelectrodes utilized in a microfluidic system, students explored the surfaces of various microelectrodes with SEM. On the basis of the visualization of the microelectrodes with SEM, students formed a hypothesis on the impact of electrode surface area on the sensitivity and limit of detection. Cyclic voltammetry in a classical three-electrode system was used to experimentally examine the relationship between electrode surface area and sensitivity. The module concluded with the use of the fabricated 3D-printed chip and amperometry to develop a calibration curve and determination of an unknown concentration of analyte. This work highlights the integration of 3D-printing, SEM, microfluidics, and electrochemistry into the upper-level undergraduate curriculum.