Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cytokine tumor necrosis factor (TNF)-alpha has been causally linked to left ventricular (LV) remodeling, but the molecular basis for this effect is unknown. Matrix metalloproteinases (MMPs) have been implicated in cardiac remodeling and can be regulated by TNF-alpha. This study tested the central hypothesis that administration of a TNF-alpha blocking protein would prevent the induction of MMPs and alter the course of myocardial remodeling in developing LV failure. Adult dogs were randomly assigned to the following groups: 1) chronic pacing (250 beats/min, 28 days, n = 12), 2) chronic pacing with concomitant administration of a TNF-alpha blocking protein (TNF block) using a soluble p75 TNF receptor fusion protein (TNFR:Fc; administered at 0.5 mg/kg twice a week subcutaneously, n = 7), and 3) normal controls (n = 10). LV end-diastolic volume increased from control with chronic pacing (83 +/- 12 vs. 118 +/- 10 ml, P < 0.05) and was reduced with TNF block (97 +/- 9 ml, P < 0.05). MMP zymographic levels (92 kDa, pixels) increased from control with chronic pacing (36,848 +/- 9,593 vs. 87,247 +/- 12,912, P < 0.05) and was normalized by TNF block. Myocardial MMP-9 and MMP-13 levels by immunoblot increased with chronic pacing relative to controls (130 +/- 10% and 118 +/- 6%, P < 0.05) and was normalized by TNF block. These results provide evidence to suggest that TNF-alpha contributes to the myocardial remodeling process in evolving heart failure through the local induction of specific MMPs.
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PMID:TNF-alpha and myocardial matrix metalloproteinases in heart failure: relationship to LV remodeling. 1189 63

Heart failure is associated with increased myocardial expression of TNF-alpha. However, the role of TNF-alpha in the development of heart failure is not fully understood. In the present study, we investigated the contribution of TNF-alpha to myocardial mitochondrial dysfunction, oxidative stress, and apoptosis in a unique dog model of heart failure characterized by an activation of all of these pathological processes. Male mongrel dogs were randomly assigned (n = 10 each) to 1) normal controls; 2) chronic pacing (250 beats/min for 4 wk) with concomitant administration of etanercept, a soluble p75 TNF receptor fusion protein, 0.5 mg/kg subcutaneously twice weekly; 3) chronic pacing with administration of saline vehicle. Mitochondrial function was assessed by left ventricular (LV) tissue mitochondrial respiratory enzyme activities. Oxidative stress was assessed with aldehyde levels, and apoptosis was quantified by photometric enzyme immunoassay for cytoplasmic histone-associated DNA fragments and terminal deoxynucleotide transferase-mediated nick-end labeling (TUNEL) assays. LV activity levels of mitochondrial respiratory chain enzyme complex III and V were reduced in the saline-treated dogs and restored either partially (complex III) or completely (complex V) in the etanercept-treated dogs. Aldehyde levels, DNA fragments, and TUNEL-positive cells were increased in the saline-treated dogs and normalized in etanercept-treated dogs. These changes were accompanied by an attenuation of LV dilatation and partial restoration of ejection fraction. Our data demonstrate that TNF-alpha contributes to progressive LV dysfunction in pacing-induced heart failure, mediated in part by a local impairment in mitochondrial function and increase in oxidative stress and myocyte apoptosis.
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PMID:In vivo TNF-alpha inhibition ameliorates cardiac mitochondrial dysfunction, oxidative stress, and apoptosis in experimental heart failure. 1520 65