Identification of Biologically Active Compounds That Drive DACH1 Expression

Diminished expression of the transcription factor Dachshund homolog 1 (DACH1) was recently identified as a major kidney injury susceptibility factor for both podocytes and tubular cells. Therapeutic strategies that augment DACH1 expression in these cell types are high yield approaches that may prevent chronic kidney disease (CKD) progression. Transcription factor modeling of the DACH1 promoter predicts the presence of several glucocorticoid response elements. We show that glucocorticoid (GC) administration caused early and sustained induction of DACH1 expression in both human podocytes and human embryonic kidney (293T) cells. While we speculate that DACH1 may be a central transcriptomic regulator of the beneficial GC response, GCs are riddled with systemic toxicities that limit their use. With this in mind, we designed a high throughput screening assay to identify novel biologically active compounds that drive DACH1 promoter activity. To do this, we cloned the DACH1 promoter, including the 3kb immediately upstream of its ATG start site, into a luciferase reporter construct (DACH1-Luc). We are currently developing stably transfected 293T cell lines that carry the DACH1-Luc or control vector alone. Our plan is to use these cells to screen a 4,000 compound library from the National Cancer Institute (NCI). Compounds will be selected based on their ability to drive luciferase activity, after which their biological activity will be confirmed by western blotting for DACH1 protein in compound-treated cells. Our goal is to test the therapeutic potential of select lead compounds in mouse models of CKD and ultimately in human clinical trials.