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theses

The Keap1–Nrf2–ARE system represents a crucial antioxidant defense mechanism that protects cells against oxidative stress-related diseases and inflammation. Activation of this system leads to elevated expression of a variety of antioxidant defense proteins and enzymes important for protection against oxidative damage, inflammation and tumorigenesis. Targeting Keap1–Nrf2 protein–protein interaction (PPI) has become a promising therapeutic strategy for several oxidative stress conditions and inflammatory diseases including chronic kidney disease, pulmonary fibrosis, chronic obstructive pulmonary disorder (COPD), and cancer chemoprevention. Several PPI inhibitors of Keap1–Nrf2 system have been reported; Tecfidera® is one of these inhibitors that is FDA approved for treatment of patients with relapsing multiple sclerosis. Inhibitors of Keap1–Nrf2 PPI are generally classified into direct and indirect inhibitors. Indirect inhibitors of Keap1–Nrf2 PPI are electrophilic species and can cause off-target side effects. Presently, scientists have been focusing on direct inhibitors of Keap1–Nrf2 PPI. In this work, we are focusing on the discovery of potent direct inhibitors of Keap1−Nrf2 PPI by performing a comprehensive structure-activity relationship (SAR) study in currently available scaffolds, or by designing new scaffolds. A fluorescence polarization (FP) assay has been used to evaluate the potency of synthesized compounds in vitro and cell-based assays have been used to test the most active compounds, resulting in the discovery of highly potent non-electrophilic Nrf2 activators. One of the best compounds discovered, 65v (LH835), has an IC50 of 144 ± 5 nM in the fluorescence polarization assay, and 1.7 ± 0.24 nM in a TR-FRET assay. Furthermore, we have demonstrated that the 65v (LH835) is an efficacious inducer of Nrf2 targeted genes in HepG2 C8 cells, exhibiting activity better than the well-known electrophilic activator, sulforaphane. Our direct inhibitors of Keap1–Nrf2 PPI could potentially be developed into drugs for the treatment of a number of oxidative stress-related diseases and conditions.

ETD_8730

Ph.D.

Includes bibliographical references

by Dhulfiqar Ali Abed

doi:10.7282/T35T3PXF

ETD doctoral

The author owns the copyright to this work.