Chronic, non-healing wounds of the skin are serious medical complications that affect over 6.5 million Americans, especially older adults. These wounds include pressure sores, diabetic foot ulcers and venous ulcers. There are numerous surgical and dressing treatments for these wounds, but because there are over 70,000 lower-limb amputations each year arising from these wounds, it is clear that new treatments are needed. Strikingly, there are almost no pharmaceutical therapies to accelerate healing of chronic wounds. A major contributor to chronic wounds is a prolonged inflammatory state, and reducing inflammation may be a way to accelerate healing of chronic wounds. Unfortunately, many commonly used anti-inflammatory drugs hinder chronic wound healing; thus, new ways of reducing inflammation are needed. An essential factor in wound healing and an important regulator of inflammation is Nrf2, a transcription factor that induces many cytoprotective and antioxidant genes. As seen in other inflammatory disorders, activating Nrf2 could be a useful therapeutic strategy to treat chronic skin wounds. There are a number of covalent Nrf2 activators, but they are not selective for Nrf2, which is problematic because some of the off-target effects of these molecules are at proteins that hinder chronic wound healing. The central hypothesis is that pharmacologic activation of Nrf2 with non-covalent small molecules will accelerate wound healing, which could lead to new therapeutics to treat chronic wounds. Finding a selective activator of Nrf2 is key to this proposal, so the focus of the proposed studies is on non-covalent Nrf2 activators, because they are likely more selective than non-electrophilic activators. Non-covalent Nrf2 activators can be developed by inhibiting the interaction of Nrf2 with its negative regulator, Keap1. The preliminary data for this proposal were generated using ligand-based drug design to develop nanomolar inhibitors of the Keap1/Nrf2 interaction. These molecules inhibit the interaction of Keap1 and Nrf2 in vitro, and they induce the expression of Nrf2 target genes ex vivo.
Aim 1 will optimize non-covalent Nrf2 activators by maintaining affinity/potency, increasing metabolic stability, and increasing aqueous solubility.
Aim 2 demonstrate that they induce Nrf2 target genes ex vivo and that they are capable of healing scratch wounds in cell culture. Finally, Aim 3 will validate these non-covalent Nrf2 activators in a mouse model of chronic wound healing. These studies will be supported by metabolism and pharmacokinetics studies, to develop high-affinity, metabolically stable, in vivo probes of Nrf2 activation for chronic wounds. These experiments are significant because they will develop novel in vivo probes of non-covalent Nrf2 activation, and they are innovative because they will open up new therapeutic strategies to treat chronic wounds.
The proposed research is relevant to public health because it seeks to develop a treatment strategy for chronic non-healing wounds and because there are currently no good pharmaceutical therapies for accelerating healing in chronic wounds. Thus, the proposed research is relevant to the part of NIH's mission that fosters ?fundamental creative discoveries, innovative research strategies, and their applications as a basis for ultimately protecting and improving health? and that ?supports research in the causes, diagnosis, prevention, and cure of human diseases.? The proposed research is relevant to NIAMS's long-range plan (Part II.J) that deals with ?discovering small molecular activators and inhibitors of cellular processes as potential therapeutic agents? in skin diseases.
| Richardson, Benjamin G; Jain, Atul D; Potteti, Haranatha R et al. (2018) Replacement of a Naphthalene Scaffold in Kelch-like ECH-Associated Protein 1 (KEAP1)/Nuclear Factor (Erythroid-derived 2)-like 2 (NRF2) Inhibitors. J Med Chem 61:8029-8047 |
