Statin treatment reduces matrix degradation capacity of proinflammatory polarized macrophages.

BACKGROUND AND AIMS: Macrophages are versatile immune cells involved in tissue degradation and remodeling. Proinflammatory macrophages have the highest capacity of matrix degradation and proteolysis. Within atherosclerotic lesions, proinflammatory macrophages are associated with unstable plaques. Statins have been demonstrated to increase plaque stability. Possible changes of polarized macrophage tissue degradation behavior under statin treatment are currently unknown. METHODS: Polarized macrophages were tested in vitro for matrix degradation capacity with or without statin treatment. RESULTS: Proinflammatory macrophages show high matrix degradation capacity, which is lost after statin treatment. Statin concentrations were within a physiological range and did not influence overall macrophage polarization. Proinflammatory macrophages showed however a loss of filopodia where activators of MMPs are located. Loss of matrix degradation in proinflammatory macrophages was associated with changes of MMP14 activation and loss of uPAR localization at filopodia. Supplementation of mevalonate restored localization of uPAR to cellular protrusions and matrix degradation capacity. CONCLUSION: Statins reduce the matrix degradation potential of proinflammatory macrophages by reducing uPAR localization to cellular filopodia and reducing intracellular MMP14 activation.

Regulation of the fibrinolytic potential of cultured human umbilical vein endothelial cells: astragaloside IV downregulates plasminogen activator inhibitor-1 and upregulates tissue-type plasminogen activator expression.

We have investigated whether the saponin astragaloside IV (AS-IV), a 3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosylcycloastragenol, purified from the Chinese herb drug Astragalus membranaceus, which is used in traditional Chinese medicine to treat cardiovascular diseases, might affect the fibrinolytic potential of cultured human umbilical vein endothelial cells (HUVECs). When HUVECs were conditioned with AS-IV, a dose (0.01-100 microg AS-IV/ml)- and time-dependent decrease in plasminogen activator inhibitor type 1 (PAI-1) and an increase in tissue-type plasminogen activator (t-PA) synthesis were observed, which were significant from 1 microg AS-IV/ml and from 12 h of incubation with 100 microg AS-IV/ml. PAI-1 antigen decreased from 641 +/- 86 to 318 +/- 18 ng/10(5) cells/24 h, whereas t-PA antigen increased from 4.1 +/- 0.3 to 9.7 +/- 0.4 ng/10(5) cells/24 h after addition of 100 microg AS-IV/ml. PAI-1 activity decreased to 30% of control level, whereas t-PA activity and t-PA-PAI-1 complexes reached a maximum stimulation of 3- and 5-fold over control levels, respectively, in the conditioned media of HUVECs treated with 100 microg AS-IV/ml for 24 h. PAI-1-specific mRNA expression decreased to 55% (2.2 kb) and 72% (3.2 kb), 66% (2.2 kb) and 88% (3.2 kb), and 19% (2.2 kb) and 41% (3.2 kb) of control values after incubation for 6, 12 and 18 h, respectively, whereas t-PA-specific mRNA increased 2-, 2.5- and 1.4-fold in HUVECs treated with 100 microg/ml AS-IV for 6, 12, and 18 h, respectively. In conclusion our data give evidence that in fact AS-IV can increase the fibrinolytic potential of cultured HUVECs not only by upregulating the expression of t-PA as NG-R1 does, but also by downregulating the expression of PAI-1.