Expression of chemokine by human coronary-artery and umbilical-vein endothelial cells and its regulation by inflammatory cytokines.

BACKGROUND: Activation of the endothelium is a critical event in the process of inflammation and is associated with the production of chemokines. OBJECTIVE: To evaluate the proinflammatory cytokine-induced chemokine repertoire of human coronary-artery endothelial cells (HCAEC) both at the messenger RNA (mRNA) level and at protein level in direct comparison with that of human umbilical-vein endothelial cells (HUVEC). METHODS: Human coronary-artery and human umbilical-vein endothelial cells were obtained commercially and experimental data were derived from cell cultures between passage levels 3 through 6. Supernatant fluids from cytokine [tumor necrosis factor-alpha (TNF-alpha), interleukin-1-alpha, and anti-TNF R55] stimulated endothelial cell cultures were used to study chemokine release. Sandwiched ELISA assays, obtained commercially, were used to estimate cell culture supernatant fluid levels of the selected chemokines: monocytic chemotactic protein-1, regulated upon activated normal T cells expressed and secreted, interleukin-8, transforming growth factor-beta-2 (TGF-beta2), and gamma interferon protein-10. Expression of messenger RNA was determined using selected labeled riboprobes (32P UTP) in a ribonuclease protection assay using total cellular mRNA. RESULTS: Upon in-vitro stimulation with TNF-alpha and interleukin-1-alpha, production of regulated-upon-activated-normal-T-cells expressed and secreted (RANTES) protein by HCAEC was significantly increased relative to that by HUVEC, the greatest effect being found with interleukin-1-alpha. The opposite effect, however, was noted for levels of monocytic-chemotactic-protein-1 protein, which were detected in HUVEC at significantly higher levels than they were in HCAEC challenged by those cytokines. Production of gamma interferon-inducible protein-10 (gammaIP-10) by HUVEC was induced by TNF-alpha and interleukin-1-alpha, whereas only a modest induction by interleukin-1-alpha was seen in HCAEC. TGF-beta-2 protein was constitutively expressed in HCAEC but not in HUVEC. Expression of mRNA was analyzed by the ribonuclease-protectionassay. RANTES mRNA was expressed in HCAEC from 3 h through 48 h after treatment with TNF-alpha, whereas only a modest induction of RANTES was expressed in HUVEC 24 h and 48 h after treatment with TNF-alpha. Monocytic-chemotactic-protein-1 mRNA was constitutively expressed by both types of cell, but the basal levels in HCAEC was significantly higher than in HUVEC. HCAEC constitutively expressed both TGF-beta-1 and TGF-beta-2 mRNA, whereas HUVEC constitutively expressed TGF-beta-1 only. CONCLUSION: Our data indicate that HCAEC and HUVEC express chemokines differently, which could contribute to or influence site-specific recruitment of subsets of leukocytes.

Flow parameters associated with hydrodynamic cell injury.

Two flow parameters are proposed for the analysis of flows that have potential to damage animal cells. They are the state of stress (characterized by the second invariant of the stress tensor) and the flow classification parameter R(D) (which is related to the possibility of stress relaxation). We consider the flow that occurs when a 1.7-mm bubble collapses at a liquid interface. Using these two parameters, we show the regions in which the flow is strong in terms of high hydrodynamic stresses and elongation characteristics.