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Identification and Validation of a Novel WNK2 Inhibitor: A New Genetically Informed Target for Osteoarthritis Drug
Shivakumar R Veerabhadraiah1, Ying Ma1, Subramanya Hegde2
1Department of Orthopaedics, University of Utah, Salt Lake City, Utah 84108, United States.
Abstract:
Osteoarthritis (OA) is a disease characterized by loss of joint space, degeneration of cartilage at articular surfaces, remodeling of bone and other joint tissues, low-grade inflammation, and pain. It is a leading cause of disability in the aging population. We do not have effective disease-modifying drugs because we lack a comprehensive understanding of the genetic pathways underlying OA development. Our recent work demonstrated that dominant hypermorphic mutations in the osmotic stress sensing kinase, WNK2, are associated with OA susceptibility. To explore WNK2 inhibition as a potential disease-modifying osteoarthritis drug, we identified a WNK2 inhibitor by using a combination of computational and experimental approaches. We used AlphaFold2 to model the WNK2 kinase domain with high confidence (pLDDT score >90), enabling virtual screening of 4.8 million compounds in the ZINC database. Structure-based filtering prioritized 53 candidates interacting with WNK2-specific residues Glu245 and Glu249, with binding energies from -4 to -8 kcal/mol. M04, (1-(6-((3,5-bis-(trifluoromethyl)-benzyl)-(methyl)-amino)-pyrimidin-4-yl)-pyrrolidin-2-yl)-methanol, emerged as a partially selective WNK2 inhibitor with minimal cytotoxicity in human T/C-28a2 chondrocyte cells (cell viability IC50 = 416 μM). M04 inhibited IL1β-mediated proinflammatory gene expression in primary human chondrocytes. RNaseq analysis comparing M04 vs a pan-WNK inhibitor in primary human chondrocytes indicated that M04 was a more effective at reducing expression of IL1β-induced OA-associated pathways. Further studies indicated the R-enantiomer is the active form of the molecule. These findings position M04 as a promising lead for WNK2-targeted OA therapy, supporting further in vivo studies for optimization and validation.
Insights
Researchers identified M04, a WNK2 inhibitor, as a potential osteoarthritis drug. This molecule shows promise in reducing inflammation and modifying disease pathways, offering hope for new osteoarthritis therapies.
Area of Science:
- Biochemistry
- Genetics
- Pharmacology
Background:
- Osteoarthritis (OA) is a major cause of disability, driven by cartilage degeneration and bone remodeling.
- Current treatments lack disease-modifying capabilities due to incomplete understanding of OA genetic pathways.
- WNK2 kinase mutations are linked to OA susceptibility.
Purpose of the Study:
- To identify and characterize a WNK2 inhibitor for potential OA disease modification.
- To explore WNK2 as a therapeutic target for osteoarthritis.
Main Methods:
- Computational modeling (AlphaFold2) and virtual screening of 4.8 million compounds.
- Structure-based filtering to identify WNK2-specific inhibitors.
- Experimental validation including cytotoxicity assays, gene expression analysis, and RNA sequencing.
Main Results:
- A WNK2 inhibitor, M04, was identified with high confidence modeling and virtual screening.
- M04 demonstrated partial selectivity for WNK2, low cytotoxicity, and inhibited IL1β-mediated inflammation in chondrocytes.
- M04 effectively reduced OA-associated pathways, with the R-enantiomer being the active form.
Conclusions:
- M04 is a promising lead compound for WNK2-targeted osteoarthritis therapy.
- Further in vivo studies are warranted for M04 optimization and validation.
- Targeting WNK2 offers a novel strategy for developing disease-modifying osteoarthritis drugs.
