Exogenous leukocyte and endogenous elastases can mediate mitogenic activity in pulmonary artery smooth muscle cells by release of extracellular matrix-bound basic fibroblast growth factor

摘要: There is increasing evidence that extracellular matrix (ECM)-degrading proteinases contribute to the process of medial hypertrophy and neointimal proliferation in pulmonary vascular diseases. However, little known about how proteinases, specifically elastases, induce smooth muscle cell (SMC) hyperplasia. Our objective was determine whether exogenous human leukocyte elastase (HLE), as well endogenous elastase, could release basic fibroblast growth factor (bFGF), a potent mitogen stored ECM surrounding SMCs. Cultured ovine porcine artery SMC were pre-incubated with [125I]-bFGF. After removal unbound [125I]-bFGF, administration HLE (0-1.0 microgram /ml, 1 h) resulted concentration-dependent accumulation [125I]-bFGF conditioned medium, mirrored by depletion from ECM. The serine inhibitor elafin blocked this HLE-mediated action. Assessment Western immunoblotting further demonstrated evoked ECM-bound bFGF. When incubated serum-starved SMC, medium HLE-treated cells stimulated [3H]-thymidine incorporation, feature neutralized bFGF antibodies. In addition, exposed serum treated elastin (STE), previously shown stimulate liberated bioavailable stores, determined autoradiography, immunoblotting, stimulation DNA synthesis proliferation. Chondroitin sulfate, an STE-induced activity, attenuated studies demonstrate HLE, secreted inflammatory cells, matrix-bound bFGF, suggesting mechanism whereby through degradation ECM, associated progressive disease.