Calpain-1 inhibitors for selective treatment of rheumatoid arthritis: what is the future?
Effective small-molecule treatment of inflammatory diseases remains an unmet need in medicine. Current treatments are either limited in effectiveness or invasive. The latest biologics prevent influx of inflammatory cells to damaged tissue. Calpain-1 is a calcium-activated cysteine protease that plays an important role in neutrophil motility. It is, therefore, a potential target for intervention in inflammatory disease. Many inhibitors of calpains have been developed but most are unselective and so unsuitable for drug use. However, recent series of α-mercaptoacrylate inhibitors target regulatory domains of calpain-1 and are much more specific. These compounds are effective in impairing the cell spreading mechanism of neutrophils in vitro and raise the possibility of treating rheumatoid arthritis with a pill; however, challenges still remain. Improved bioavailability is needed and solution of their precise mode of action should prompt the development of specific calpain-1 screens for novel classes of inhibitors.
School of Chemistry & Cardiff Catalysis Institute, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK.
David J
DJ
Miller
Sarah E
SE
Adams
Maurice B
MB
Hallett
Rudolf K
RK
Allemann
D000818:Animals; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000201:enzymology*; D002154:Calpain / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D055808:Drug Discovery; D006801:Humans; D008958:Models, Molecular; D017434:Protein Structure, Tertiary / Q000187:drug effects
D015853:Cysteine Proteinase Inhibitors; D002154:Calpain; C484806:CAPN1 protein, human