Neutrophil Apoptosis and H2O2 Release by LPS in Diabetics

Seo, Ki Hyun; Na, Joo Ock; Moon, Seung Hyug; Uh, Soo Taek; Kim, Yong Hoon; Park, Choon Sik

Abstract

BACKGROUND: Bacterial infections in diabetic patients are an important cause of increased morbidity and mortality. It has been reported that bacterial infections in diabetics showed more impaired PMN functions such as reduced PMN respiratory burst and decreased microbicidal activity in inflammed tissues. Also, apoptosis(programmed cell death) is postulated to be a key mechanism for neutrophil elimination. It is very important that PMN apoptosis keeps the balance from an area of inflammation. Actuallly, as little was known about PMN apoptosis and respiratory burst in diabetes, we investigated PMN apoptosis and hydrogen peroxide production after endotoxin exposure.
METHODS
Peripheral venous blood samples were collected by routine venipuncture from healthy volunteers and diabetics to harvest neutrophils. We respectively measured the PMN apoptosis, the production of hydrogen peroxide, and the cell viability.
RESULTS
Normal neutrophils showed a tendency to decreased apoptosis after endotoxin treatment. In patients with diabetes, PMN apoptosis was significantly decreased compared with healthy controls. In addition, the LPS-induced neutrophils in diabetics demonstrated more decreased apoptosis. However, the production of hydrogen peroxide was not different between groups.
CONCLUSION
These observations suggest that the decreased PMN apoptosis in diabetics with endotoxin exposure may also affect the increased susceptibility and severity of infections.