title: Activities of neutrophil membrane-bound proteases in type 2 diabetic patients.
abstract: OBJECTIVE
  Hyperglycemia and oxidative stress in type 2 diabetes (T2DM) provoke neutrophil overstimulation and the release and/or translocation of proteases from granules to the cell surface. Although the expression of neutrophil membrane-bound elastase (MLE) is well documented, the presence of the membrane-bound form of cathepsin B (MCB) is unknown. The aim of our study was to evaluate the neutrophil MLE and MCB activities in T2DM patients and their associations with the metabolic and clinical parameters of the disease.
  
  
  METHODS
  Neutrophils were obtained from 47 T2DM patients and 20 control subjects. The activities of MLE and MCB and the intracellular activities of the examined proteases (ILE and ICB, respectively) were measured using fluorometric substrates. Additionally, the percentage equivalents of the activities, namely, MLEtot/ILEtot and MCBtot/ICBtot, were calculated. The susceptibility to inhibitors of both forms of the studied proteases was also determined.
  
  
  RESULTS
  A significant increase in the activities of MLE, MCB, ILE, and ICB was found in neutrophils from T2DM patients compared with the control group. The percentage equivalent (contribution of the total membrane-bound activities to the total intracellular activities) was also higher. A partial resistance of the membrane-bound forms toward their inhibitors was revealed. Higher activities of both the membrane-bound and the intracellular proteases were also observed in patients with poor glycemic and metabolic control. The differences between subgroups with different therapeutic schemes were also revealed.
  
  
  CONCLUSIONS
  The pathophysiological implications of the neutrophil membrane-bound forms of leukocyte elastase and cathepsin B are of great importance in the development of T2DM and its complications.
authors: Department of Pharmaceutical Biochemistry, Wroclaw Medical University, Wroclaw, Poland. Electronic address: ewa.zurawska-plaksej@umed.wroc.pl.
authors: Ewa
authors: E
authors: Zurawska-Płaksej
authors: Department of Pharmaceutical Biochemistry, Wroclaw Medical University, Wroclaw, Poland.
authors: Agnieszka
authors: A
authors: Piwowar
authors: Department and Clinic of Angiology, Hypertension and Diabetology, Wroclaw Medical University, Wroclaw, Poland.
authors: Maria
authors: M
authors: Knapik-Kordecka
authors: Department of Pharmaceutical Biochemistry, Wroclaw Medical University, Wroclaw, Poland.
authors: Maria
authors: M
authors: Warwas
mesh_terms: D016022:Case-Control Studies; D056649:Cathepsin G; D002462:Cell Membrane / Q000201:enzymology*; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000201:enzymology*; D011480:Protease Inhibitors / Q000494:pharmacology
chemical_list: D011480:Protease Inhibitors; D056649:Cathepsin G; D019272:Leukocyte Elastase
keywords: Cathepsin B; Diabetes mellitus; Leukocyte elastase; Membrane-bound proteases; Neutrophils