Chemical Modulators of the PIEZO2 Mechanoreceptor for the Study and Treatment of Pain

National Center For Advancing Translational Sciences

Investigators

Abstract

PIEZO2 is a stretch-gated ion channel expressed in touch neurons, nociceptors, and mechanosensitive epithelial cells. Under normal conditions, it mediates gentle touch and suppresses itch. Human subjects with inherited loss of function (LOF) mutations in this gene fail to develop mechanical allodynia, a very common type of chronic pain whereby normally innocuous touch becomes painful. During inflammatory and neuropathic pain, touch becomes painful (tactile allodynia), but this hypersensitivity is absent in PIEZO2 LOF patients and mice. These findings highlight PIEZO2 as a novel therapeutic target for chronic itch and mechanical pain. Agonists may relieve itch, while antagonists could treat allodynia without disrupting normal pain or temperature sensation. The goal of this collaboration is to develop high throughout screens to discover and characterize small molecule probes of the mechanosensory ion channels PIEZO2. Validated hits will be optimized, and leads will be tested in animal models to demonstrate target engagement and efficacy. To enable therapeutic discovery, the team developed PIEZO2-expressing excitable HEK293 (eHEK) cell lines co-expressing CaV3.3 and Kir2.1 for calcium imaging alongside PIEZO1 and null lines for counter-screening. A 1536-well agonist assay was optimized and used to screen ~30,000 small molecules from NCATS and NCI collections. One PIEZO2 agonist chemotype was identified and validated using orthogonal assays. Several PIEZO1 agonist hits, surprisingly including cancer drugs Cabazitaxel and Docetaxel, are also being evaluated. The team is now building a 1536-well antagonist assay leveraging the new PIEZO2 agonist. As an alternative approach, the team is developing a panning strategy to discover PIEZO2-targeting nanobodies that could functionally replace small molecules.