"Regulation of Leukocyte-Derived Matrix Metalloproteinases and Azurophi" by Martin Woo
Electronic Thesis and Dissertation Repository

Degree

Master of Science

Program

Physiology and Pharmacology

Supervisor

Dr. Douglas D. Fraser

Abstract

Diabetic Ketoacidosis (DKA) is associated with pediatric cerebrovascular-related complications. DKA-associated inflammation instigates leukocyte adherence to the brain microvascular endothelium. As adhered leukocytes release enzymes that compromise vascular integrity, we questioned a role for leukocyte-derived matrix metalloproteinases (MMPs) and azurophilic enzymes (elastase, proteinase-3, myeloperoxidase). Our aims were to measure leukocyte-derived enzymes in DKA plasma, determine associations with DKA severity and investigate their effect on the cerebrovascular endothelium.

Plasma was obtained from children with type-1 diabetes, either in acute DKA or insulin-controlled. DKA was associated with altered plasma levels of ↓MMP-2, ↑MMP-8, ↑MMP-9 and ↑TIMP-4, which are largely leukocyte in origin. DKA was also associated with elevated plasma leukocyte elastase, proteinase-3 and myeloperoxidase. MMP-8, MMP-9 and proteinase-3 were positively correlated with DKA severity. Azurophilic enzymes decreased ZO-1 and degraded β-catenin in cerebrovascular endothelium.

In summary, DKA is associated with dynamic regulation of leukocyte proteolytic enzymes that can impair blood brain barrier integrity.

Share

COinS