Serum from patients with severe heart failure downregulates eNOS and is proapoptotic - Role of tumor necrosis factor-alpha

Background-Cytokine activation and endothelial dysfunction are typical phen omena of congestive heart failure (CHF). We tested the hypothesis that incu bating human umbilical vein endothelial cells with serum from patients with CHF will downregulate endothelial constitutive nitric oxide synthase (eNOS ) and induce apoptosis, Methods and Results-We studied 21 patients with severe CHF, Levels of tumor necrosis factor-alpha (TNF-alpha) and several neuroendocrine parameters we re assessed. eNOS was measured by Western Blot analysis and apoptosis by op tical microscopy and flow cytometry. We observed(1) eNOS downregulation (di fference versus healthy subjects at 24 hours [P < 0.05] and 48 hours [P < 0 .001]), (2) nuclear morphological changes typical of apoptosis; and (3) a h igh apoptotic rate with propidium iodide (increasing from 2.1 +/- 0.4% to 1 1.3 +/- 1.2% at 48 hours; P < 0.001 versus healthy subjects) and annexin V. An anti-human TNF-alpha antibody did not completely counteract these effec ts. A strong correlation existed between eNOS downregulation and apoptosis (r = -8.89; P < 0.001). Conclusions-Serum from patients with severe CHF downregulates eNOS expressi on and increases apoptosis, High levels of TNF-alpha likely play a role, bu t they cannot be the only factor responsible.