The expression profile of cytoglobin in human fibrotic lung, and the protective role of cytoglobin in hypoxia and oxidative stress in vitro

Cytoglobin (CYGB), a novel member of the globin family, has been shown to be upregulated in response to hypoxia, oxidative stress and fibrogenesis. Presented here is evidence of CYGB expression within cells of fibrotic lesions taken from patients with Idiopathic Pulmonary Fibrosis (IPF) and Chronic Obstructive Pulmonary Disease (COPD). CYGB staining was observed in fibroblasts, endothelial cells, type II pneumocytes, type I pneumocytes, haematopoietic stem cells and inflammatory cells, which were identified using cell specific markers. Cell types which express other members of the globin family, including smooth muscle and red blood cells were negative for CYGB. Fibroblasts were consistently positive for CYGB. CYGB expression was consistently positive within the lesion, and more variable at the edge. This study also provides evidence of an increase in CYGB expression in response to hypoxic and oxidative stress in vitro; however there was no evidence of cytoprotection with over expression of CYGB in response to these insults. There is evidence presented here that the increase in CYGB expression with fibrosis previously reported in the literature, is likely to relate to the hypoxic environment of the lesion and the influx of fibroblasts which are consistently CYGB positive. CYGB is likely to have a role in oxygen and redox homeostasis.

Name dc:type.qualificationname

d_ph

Level dc:type.qualificationlevel

d_ph

Grantor dc:publisher.institution

University of Birmingham

Year dc:date.issued

2010

Author dc:creator

• Carpenter, Melinda

• QR Microbiology