Summary
Plasma kallikrein (PK) is a serine protease generated from plasma prekallikrein, an
abundant circulating zymogen expressed by the Klkb1 gene. The physiological actions
of PK have been primarily attributed to its production of bradykinin and activation
of coagulation factor XII, which promotes inflammation and the intrinsic coagulation
pathway. Recent genetic, molecular, and pharmacological studies of PK have provided
further insight into its role in physiology and disease. Genetic analyses have revealed
common Klkb1 variants that are association with blood metabolite levels, hypertension,
and coagulation. Characterisation of animal models with Klkb1 deficiency and PK inhibition
have demonstrated effects on inflammation, vascular function, blood pressure regulation,
thrombosis, haemostasis, and metabolism. These reports have also identified a host
of PK substrates and interactions, which suggest an expanded physiological role for
this protease beyond the bradykinin system and coagulation. The review summarises
the mechanisms that contribute to PK activation and its emerging role in diabetes
and metabolism.
Keywords
Plasma kallikrein - diabetes - Klkb1 - contact activation pathway