Serum from patients with chronic obstructive pulmonary disease promotes proangiogenic behavior of the vascular endothelium

OBJECTIVE

It has been documented that COPD is a risk factor for lung cancer. In COPD patients, changes in lung angiogenesis - a critical process in the development of lung cancer - have been poorly investigated. We aimed to determine whether serum from COPD patients could promote the proangiogenic capabilities of endothelial cells in vitro.

PATIENTS AND METHODS

The research was carried out using sera from COPD patients and healthy volunteers, endothelial cells EA.hy926, and bronchial epithelial cells. The concentration of angiogenic molecules was quantified using ELISA tests. The proliferation and migration of EA.hy926 were tested using fluorescence-based methods. Tube formation was analyzed with a commercially available assay.

RESULTS

Sera from COPD patients and conditioned media generated by epithelial cells exposed to these sera stimulate proliferation, but not migration, of EA.hy926. This coincided with increased tube formation in both experimental regimens. The sera from COPD patients contained increased levels of CCL2, CCL21, and HGF, whereas the conditioned media generated by epithelial cells treated with these sera exhibited increased levels of CCL2, CCL21, CXCL8, FGF, and sICAM-1. The concentration of angiogenic markers in the sera and conditioned media, and their effect on the behavior of the endothelium were independent of smoking status (COPD and controls), stage of obstruction, and disease group (COPD).

CONCLUSIONS

The increased incidence of lung malignancy in COPD patients may be associated, at least to some extent, with the direct and indirect proangiogenic activity of their sera (via alterations in the secretome of epithelial cells).

Interleukin-17: a mediator of inflammatory responses

Interleukin-17 (IL-17) is a prototype member of a new cytokine family with six species identified to date. IL-17 is secreted mainly by activated CD4(+) and CD8(+) T lymphocytes, while its receptor is distributed ubiquitously. IL-17 has been classified as a proinflammatory cytokine because of its ability to induce the expression of many mediators of inflammation, most strikingly those that are involved in the proliferation, maturation and chemotaxis of neutrophils. Increased levels of IL-17 have been associated with several conditions, including airway inflammation, rheumatoid arthritis, intraperitoneal abscesses and adhesions, inflammatory bowel disease, allograft rejection, psoriasis, cancer and multiple sclerosis. This review provides an overview of IL-17 activities, concentrating on those that lead to neutrophil recruitment.