Inflammatory bowel disease (IBD) causes inflammation of the digestive tract. Although the etiology is complex, studies of patient genetics have shed light on genes and pathways that contribute to IBD pathophysiology. Because a correlation was found between loss-of-function mutations of anti-inflammatory cytokine interleukin (IL)-10 and increased risk of IBD, a potential target for therapeutic intervention is increasing levels of IL-10 in dendritic cells that are numerous inside the gut but lack high levels of IL-10. Using an ex vivo model, we screened 60,000 compounds from the DOS and commercial screening collections for validated hits that up-regulate IL-10. Transcriptional profiles of large collections of DOS compounds and other compounds with known modes of action have been profiled using the L1000 assay system. This allowed us to query the L1000 data to see if the IL-10 DOS leads would cluster with any known classes of bioactives. Analysis of the transcriptional response of IL-10 DOS hits in comparison to other compound classes that up-regulate IL-10 provided insight into the modes of action of these different compound screening collections. We found that the screening collection SnAr 9-para clustered with compounds that perturb microtubule polymerization. Based on this correlation, we hypothesized that compounds located in the SnAr 9-para library might affect microtubule dynamics. This led to the experimentation of biochemical and cell-based assays on active and inactive analogs of IL-10 enhancers. In the biochemical assay, the active analog more closely resembled the profile of an inhibitor nocadozole, while the inactive analog did not affect tubulin polymerization. Additionally, the results from the cell-based assay displayed the active analog appearing to have a decrease in the amount of spindles it contained in comparison to the control DMSO in treated cells. From these results we concluded that the IL-10 enhancing activity of SnAr 9-para leads tracks with suppression of tubulin polymerization. Although we were able to successfully find the probable mechanism for this library, this set of series will be deprioritized because of toxicity concerns associated with microtubule modulators.
PROJECT: Transcriptional profiling yields insights into the targets of small molecule IL-10 enhancers
Do not focus on the destination; enjoy the journey: It is an often used expression, and one that definitely applies to the experience of the Broad’s SRPG program. Here, the focus is not on proving yourself, but improving yourself. This approach allowed me to grow and learn tremendously as a scientist and as a person.