Generation of LexA enhancer-trap lines in Drosophila by an international scholastic network.

Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development, and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

Acute alcohol intake induces SOCS1 and SOCS3 and inhibits cytokine-induced STAT1 and STAT3 signaling in human monocytes.

BACKGROUND: Acute alcohol consumption is associated with induction of immuno-inhibitory cytokines and down-regulation of pro-inflammatory responses to various pathogens. We previously reported that alcohol activates janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling leading to IL-10 induction. The JAK-STAT pathway also activates its own negative regulators, suppressors of cytokine signaling (SOCS) 1 and SOCS3. SOCS proteins are inducible inhibitors that negatively regulate STAT3/STAT1 signaling pathways induced by cytokines, IL-6 or IFNs. Here we aimed to explore the effect of acute alcohol on induction of SOCS1/SOCS3 and regulation of STAT3/STAT1 pathways induced by IL-6 or IFNs in human monocytes. METHODS: Blood samples from normal volunteers were collected before and 24 hours after consumption of 2 ml vodka/kg body weight. For in vitro experiments human monocytes were pretreated with ethanol (EtOH) followed by stimulation with cytokines; proteins were analyzed by Western blot, nuclear protein binding to DNA by EMSA, and RNA by real time PCR. RESULTS: Acute in vivo or in vitro alcohol treatment increased both SOCS1 and SOCS3 RNA expression in monocytes. Alcohol treatment resulted in increased STAT3 and STAT1 DNA binding capacity. Activation of both STAT1 and STAT3 has been shown to induce SOCS1/3. We hypothesized that induction of SOCS proteins by alcohol in turn may lead to modulation of cytokine signaling through STAT1 and STAT3. Indeed, we observed significant down-regulation of IL-6-, IFNalpha- and IFNgamma-induced STAT1 DNA binding as well as inhibition of IL-6- and IFNgamma-induced STAT3 when alcohol was added to monocytes 3 hours prior to the cytokine stimulation. Consistent with inhibition of IL-6-induced STAT3 DNA binding in alcohol-pretreated cells, the levels of IL-6-dependent genes, MCP-1 and ICAM-1, was reduced after IL-6 stimulation. Similar to EtOH alone, combined EtOH+IL-6 simulation resulted in increased expression of both SOCS3 and SOCS1 genes. CONCLUSION: While acute alcohol treatment alone activates STAT1/3 signaling pathways and induces SOCS3 and SOCS1 levels in monocytes, alcohol also leads to down-regulation of IL-6-, IFNalpha-, and IFNgamma-induced signaling via STAT1/STAT3 pathways, likely through excessive SOCS activation.