Matrix metalloproteinases and TIMP-1 production by peripheral blood granulocytes from COPD patients and asthmatics

Both asthmatic and COPD patients were found to have increased amounts of gr anulocytes and matrix metalloproteinase-9 (MMP-9) in their sputum. The pres ent study was conducted to investigate whether the elevated amounts of MMP- 9 and TIMP-1 found in such patients' airways may be linked to an enhanced s ecretion by granulocytes. Blood granulocytes from asthmatics (n = 10), COPD patients (n = 11), and healthy controls (n = 11) were isolated and culture d under basal conditions or after stimulation by phorbol 12-myristate 13-ac etate (PMA) or N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). MMP-9 activity was detected by zymography while MMP-8 and TIMP-1 levels were meas ured by ELISA. In zymography, pro- and activated forms of MMP-9 were presen t in each group (healthy subjects, asthmatics, and COPD patients). Spontane ous release was not different between the three groups. Stimulation by fMLP and PMA increased to a similar extent the release of MMP-9 by granulocytes in all the three groups. TIMP-1 levels were also increased after stimulati on by PMA and fMLP only in healthy subjects and COPD patients. MMP-8 levels were barely detectable. We conclude that circulating granulocytes from COP D patients and asthmatics do not display an abnormal secretion of MMP-9, an d that granulocytes from asthmatics have an impaired ability to release TIM P-1 upon stimulation.