Functional Roles of Furin in Cardio-Cerebrovascular Diseases.

Furin plays a major role in post-translational modification of several biomolecules, including endogenous hormones, growth factors, and cytokines. Recent reports have demonstrated the association of furin and cardio-cerebrovascular diseases (CVDs) in humans. This review describes the possible pathogenic contribution of furin and its substrates in CVDs. Early-stage hypertension and diabetes mellitus show a negative correlation with furin. A reduction in furin might promote hypertension by decreasing maturation of B-type natriuretic peptide (BNP) or by decreasing shedding of membrane (pro)renin receptor (PRR), which facilitates activation of the renin-angiotensin-aldosterone system (RAAS). In diabetes, furin downregulation potentially leads to insulin resistance by reducing maturation of the insulin receptor. In contrast, the progression of other CVDs is associated with an increase in furin, including dyslipidemia, atherosclerosis, ischemic stroke, myocardial infarction (MI), and heart failure. Upregulation of furin might promote maturation of membrane type 1-matrix metalloproteinase (MT1-MMP), which cleaves low-density lipoprotein receptor (LDLR), contributing to dyslipidemia. In atherosclerosis, elevated levels of furin possibly enhance maturation of several substrates related to inflammation, cell proliferation, and extracellular matrix (ECM) deposition and degradation. Neuronal cell death following ischemic stroke has also been shown to involve furin substrates (e.g., MT1-MMP, hepcidin, and hemojuvelin). Moreover, furin and its substrates, including tumor necrosis factor-α (TNF-α), endothelin-1 (ET-1), and transforming growth factor-β1 (TGF-β1), are capable of mediating inflammation, hypertrophy, and fibrosis in MI and heart failure. Taken together, this evidence provides functional significance of furin in CVDs and might suggest a potential novel therapeutic modality for the management of CVDs.