We have developed a PEX1-G843D patient skin cell-based screening assay to identify novel drugs that recover peroxisome functions. We used this to successfully identify a group of drugs called flavonoids and then using structure-activity studies, we identified the strongest flavonoid compound to recover PEX1-G843D functions in cell lines. This successful assay is continuing to be used to screen additional compounds at the NIH in collaboration with Dr. Joseph Hacia and the Global Foundation for Peroxisome Disorders.
Learn more about this screening assay
Learn more about structure-activity relationships in flavonoids
We are currently using this assay to study peroxisome functions in our patient cell lines with various gene changes. We are also working on finding and testing other cellular assays to study peroxisome functions in patient fibroblasts that are not suited for the reporter screening assay.
Fluorescent microcopy image of a ZSD patient fibroblast cell line expressing a green fluorescent protein (GFP) reporter with a peroxisome‐targeting signal (GFP‐PTS1). Fibroblasts shown on the left fail to import the GFP-PTS1 protein while those shown on the right import the GFP-PTS1 protein as seen by the punctated green fluorescence that co-localizes with peroxisomes. Provided by Xuting Sun, Master Student in our lab in 2017.
Confocal immunofluorescence microscopy image showing PEX14 protein in green bound to peroxisome membranes and nuclei in blue in normal control fibroblasts. This experiment was done to quantify the number of peroxisomes across different patient cell lines. Provided by Xuting Sun, Master Student in our lab in 2017.
We are working on a project to correct the common PEX1-G843D variant into a normal PEX1 protein in patient’s skin cell lines using the CRISPR/Cas9 gene editing technology. This project will help to dissect out the genetic background of the patient to determine if additional mutations are contributing to the disease. We hope that this work will set the stage for future research on gene editing as a potential therapy.