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 phenomena of congestive heart failure (CHF). We tested the hypothesis that incubating human umbilical vein endothelial cells with serum from patients with CHF will downregulate endothelial constitutive nitric oxide synthase (eNOS) and induce apoptosis.


RESULTS
We studied 21 patients with severe CHF. Levels of tumor necrosis factor-alpha (TNF-alpha) and several neuroendocrine parameters were assessed. eNOS was measured by Western Blot analysis and apoptosis by optical microscopy and flow cytometry. We observed (1) eNOS downregulation (difference 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 high apoptotic rate with propidium iodide (increasing from 2.1+/-0.4% to 11.3+/-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 effects. A strong correlation existed between eNOS downregulation and apoptosis (r = -0.89; P<0.001).


CONCLUSIONS
Serum from patients with severe CHF downregulates eNOS expression and increases apoptosis. High levels of TNF-alpha likely play a role, but they cannot be the only factor responsible.
Agnoletti
L
L
Salvatore Maugeri Foundation, Institute for Care and Research, Cardiovascular Pathophysiology Research Centre, Gussago, Brescia, Italy.
Curello
S
S
Bachetti
T
T
Malacarne
F
F
Gaia
G
G
Comini
L
L
Volterrani
M
M
Bonetti
P
P
Parrinello
G
G
Cadei
M
M
Grigolato
P G
PG
Ferrari
R
R
D000368:Aged; D017209:Apoptosis; D002478:Cells, Cultured; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000502:physiology; D005434:Flow Cytometry; D006333:Heart Failure / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
D014409:Tumor Necrosis Factor-alpha; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III