Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), essential components in the pathogenesis of immunoinflammatory diseases, are strongly induced in monocytes by direct contact with stimulated T lymphocytes. This study demonstrates that adult human serum (HS) but not fetal calf or cord blood serum displays inhibitory activity toward the contact-mediated activation of monocytes by stimulated T cells, decreasing the production of both TNF-alpha and IL-1beta. Fractionation of HS and N-terminal microsequencing as well as electroelution of material subjected to preparative electrophoresis revealed that apolipoprotein A-I (apo A-I), a "negative" acute-phase protein, was the inhibitory factor. Functional assays and flow cytometry analyses show that high-density lipoprotein (HDL)-associated apo A-I inhibits contact-mediated activation of monocytes by binding to stimulated T cells, thus inhibiting TNF-alpha and IL-1beta production at both protein and messenger RNA levels. Furthermore, apo A-I inhibits monocyte inflammatory functions in peripheral blood mononuclear cells activated by either specific antigens or lectins without affecting cell proliferation. These results demonstrate a new anti-inflammatory activity of HDL-associated apo A-I that might have modulating functions in nonseptic conditions. Therefore, because HDL has been shown to bind and neutralize lipopolysaccharide, HDL appears to play an important part in modulating both acute and chronic inflammation. The novel anti-inflammatory function of apo A-I reported here might lead to new therapeutic approaches in inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, and atherosclerosis.
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PMID:Apolipoprotein A-I inhibits the production of interleukin-1beta and tumor necrosis factor-alpha by blocking contact-mediated activation of monocytes by T lymphocytes. 1129 Jun 1

Migration of vascular smooth muscle cells (VSMC) is a crucial event in the formation of vascular stenotic lesions. Tumor necrosis factor-alpha (TNF-alpha) is elaborated by VSMC in atherosclerosis and following angioplasty. We investigated the role of nuclear factor-kappaB (NF-kappaB) in human VSMC migration induced by TNF-alpha. Adenoviral expression of a mutant form of the inhibitor of NF-kappaB, IkappaB-alphaM, suppressed TNF-alpha-triggered degradation of cellular IkappaB-alpha, inhibited activation of NF-kappaB, and attenuated TNF-alpha-induced migration. Further, IkappaB-alphaM suppressed TNF-alpha-stimulated release of interleukin-6 and -8 (IL-6 and IL-8). Neutralization of IL-6 and IL-8 with appropriate antibodies reduced TNF-alpha-induced VSMC migration. Addition of recombinant IL-6 and IL-8 stimulated migration. Collectively, our data provide initial evidence that TNF-alpha-mediated VSMC migration requires NF-kappaB activation and is associated with induction of IL-6 and IL-8 which act in an autocrine manner.
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PMID:NF-kappaB is required for TNF-alpha-directed smooth muscle cell migration. 1172 52

Intimal proliferation of smooth muscle cells (SMCs) is a key event in the vascular response to injury, including the early stages of atherosclerosis and restenosis after angioplasty. Tumor necrosis factor-alpha (TNF-alpha) has been reported to stimulate growth of cultured human SMCs, but activation of TNF receptors is also known to induce cell death by apoptosis. We report here that SMCs isolated from the neointima of injured rat aortas are characterized by increased expression of TNF-alpha in response to interleukin-1beta and gamma-interferon compared with medial SMCs. Basal and serum-stimulated DNA synthesis was higher in intimal than in medial SMCs. In contrast to previous findings on human SMCs, exposure to interleukin-1beta/gamma-interferon or TNF-alpha did not affect the growth of rat medial SMCs, inhibited DNA synthesis, and decreased cell numbers in cultures of intimal SMCs. Incubation of intimal SMCs with these cytokines also resulted in induction of terminal dUTP nick end-labeling positivity and caspase-3 expression, suggesting cell death by apoptosis, whereas medial cells were markedly less sensitive in this respect. Cytokine-induced apoptosis in intimal cells was effectively inhibited by treatment with antibodies against TNF receptors. These findings suggest that endogenous activation of TNF receptors may represent a way to limit accumulation of SMCs in injured arteries. This mechanism may also be important in SMC death in advanced atherosclerotic plaques.
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PMID:Increased rate of apoptosis in intimal arterial smooth muscle cells through endogenous activation of TNF receptors. 1174 63

Tumor necrosis factor (TNF) receptor superfamily 14 (TNFRSF14) is the cellular receptor for TNF superfamily 14 (LIGHT). Immunohistochemical staining of human carotid atherosclerotic plaques revealed a high level of expression of the TNFRSF14 in regions rich in macrophages/foam cells. To investigate the role of TNFRSF14 in the functioning of monocytes in relation to atherogenesis, we have analyzed TNFRSF14 expression levels and cellular events after stimulation of TNFRSF14 in peripheral blood monocytes or the human macrophage-like cell line, THP-1. A high level of expression of TNFRSF14 was detected in activated monocytes, in macrophages derived from monocytes, and in THP-1 cells. Concomitant activation of THP-1 cells with interferon-gamma and immobilized anti-TNFRSF14 monoclonal antibody resulted in synergistic induction of proatherogenic cytokines, such as TNF-alpha and interleukin-8. Activation of THP-1 cells with immobilized anti-TNFRSF14 monoclonal antibody induced expression of matrix metalloproteinase (MMP)-1, MMP-9, MMP-13, and tissue inhibitors of metalloproteinase-1 and -2. Furthermore, immunohistochemical staining of atherosclerotic plaques with severe infiltration of foam cells revealed that the expression patterns of TNFRSF14 and MMP-1, -9, and -13 overlapped. Treatment of THP-1 cells with soluble LIGHT also caused induction of MMP-9 and interleukin-8. These data suggest that TNFRSF14 is involved in atherosclerosis via the induction of proatherogenic cytokines and decreasing plaque stability by inducing extracellular matrix-degrading enzymes.
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PMID:Tumor necrosis factor receptor superfamily 14 is involved in atherogenesis by inducing proinflammatory cytokines and matrix metalloproteinases. 1174 58

Inflammatory processes are involved with all phases of atherosclerotic lesion growth. Tumor necrosis factor-alpha (TNFalpha) is an inflammatory cytokine that is thought to contribute to lesion development. Lymphotoxin-alpha (LTalpha) is also a proinflammatory cytokine with homology to TNFalpha. However, its presence or function in lesion development has not been investigated. To study the role of these molecules in atherosclerosis, the expression of these cytokines in atherosclerotic lesions was examined. The presence of both cytokines was observed within aortic sinus fatty streak lesions. To determine the function of these molecules in regulating lesion growth, mice deficient for TNFalpha or LTalpha were examined for induction of atherosclerosis. Surprisingly, loss of TNFalpha did not alter lesion development compared with wild-type mice. This brings doubt to the generally held concept that TNFalpha is a "proatherogenic cytokine." However, LTalpha deficiency resulted in a 62% reduction in lesion size. This demonstrates an unexpected role for LTalpha in promoting lesion growth. The presence of LTalpha was observed in aortic sinus lesions suggesting a direct role of LTalpha in modulating lesion growth. To determine which receptor mediated these responses, diet-induced atherosclerosis in mice deficient for each of the TNF receptors, termed p55 and p75, was examined. Results demonstrated that loss of p55 resulted in increased lesion development, but loss of p75 did not alter lesion size. The disparity in results between ligand- and receptor-deficient mice suggests there are undefined members of the TNF ligand and receptor signaling pathway involved with regulating atherogenesis.
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PMID:Loss of lymphotoxin-alpha but not tumor necrosis factor-alpha reduces atherosclerosis in mice. 1180 56

Inflammation has been postulated to contribute to restenosis after balloon angioplasty. Tumor necrosis factor (TNF)-alpha is a pleiotropic proinflammatory cytokine involved in many features of inflammation. We examined the tissue expression pattern of TNF-alpha and the inflammatory response to arterial injury, and the effects of a goat anti-rabbit-TNF-alpha polyclonal antibody on tissue TNF-alpha expression, inflammation and restenosis in a rabbit atherosclerotic model. At different time points following air dessication and subsequent balloon injury, fresh rabbit femoral artery tissues were homogenized and analyzed for TNF-alpha levels by quantitative TNF-alpha bioassay. Rabbits were treated with a goat anti-rabbit-TNF-alpha polyclonal antibody, Serum and tissue TNF-alpha neutralization, macrophage infiltration (as an indicator of inflammation), and neointimal areas were determined. Balloon angioplasty increased tissue TNF-alpha expression 100000-fold over baseline, and this increase persisted over 6 days after arterial injury, serum anti-TNF-alpha antibody levels were sufficient to neutralize tissue TNF-alpha activity by 60-75%, macrophage infiltration was suppressed, but did not decrease the neointimal formation. These data indicate that tissue TNF-alpha levels were markedly increased after balloon angioplasty. Anti-TNF-alpha treatment was sufficient to neutralize tissue TNF-alpha activity, reduce inflammation, but did not inhibit neointimal formation following balloon angioplasty in a rabbit atherosclerotic model.
Atherosclerosis 2002 Mar
PMID:Effect of anti-tumor necrosis factor-alpha polyclonal antibody on restenosis after balloon angioplasty in a rabbit atherosclerotic model. 1188 27

The initiation of an atherosclerotic lesion involves an endothelial cell pro-inflammatory state that recruits leukocytes and promotes their movement across the endothelium. These processes require endothelial expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial-leukocyte adhesion molecule-1 (E-selectin). Tumor necrosis factor-alpha (TNF-alpha) is a powerful inducer of these adhesion molecules. Selenium status is known to affect the rate of atherosclerosis. These experiments tested whether selenium alters cytokine-induced expression of these adhesion molecules. Human umbilical vein endothelial cells (HUVECs) were pretreated for 24 h with sodium selenite (0-2 microM) and then treated with 0 or 50 U/ml TNF-alpha in the presence of 0-2 microM selenite. ICAM-1, VCAM-1 and E-selectin were detected by ELISA and their mRNAs were evaluated by Northern blots. Selenite significantly inhibited TNF-alpha-induced expression of each adhesion molecule in a dose-dependent manner and reduced the level of the respective mRNAs. Nuclear factor-kappa B (NF-kappa B) is required for transcription of these adhesion molecule genes. Western blot analysis revealed that selenite did not inhibit the translocation of the p65 subunit of NF-kappa B to the nucleus. In conclusion, these data indicate selenium can modulate cytokine-induced expression of ICAM-1, VCAM-1 and E-selectin in HUVECs without interfering with translocation of NF-kappa B.
Atherosclerosis 2002 Apr
PMID:Inhibition of TNF-alpha induced ICAM-1, VCAM-1 and E-selectin expression by selenium. 1188 21

Type 2 diabetic mellitus (type 2 DM) comprises more than 95% of all Taiwanese patients with DM. Tumor necrosis factor-alpha (TNF-alpha) expression is linked with insulin resistance, and is under strong genetic control. The correlation between TNF promoter genotypes and type 2 DM is still controversial, because discrepancies among different studies exist. Ethnic differences play certain roles in these conflicting results, because the distribution of TNF promoter polymorphisms is different among study subjects with different racial origins. Therefore, we examined the relationship between the incidence of type 2 diabetes in Taiwanese and two polymorphisms of the TNF-alpha promoter region (positions -238 and -308) as well as the correlation between these polymorphisms and the patients' biochemical manifestations. Genomic DNA was extracted from peripheral blood cells of 261 Taiwanese patients with type 2 DM and 189 non-diabetic control study subjects, and their TNF promoter G-238A and G-308A polymorphisms were analyzed by PCR-RFLP analysis. No significant association between TNF-alpha G-238A and G-308A polymorphisms with type 2 diabetic incidence was observed. However, associations between TNF-alpha G-238A and low-density lipoprotein-cholesterol and between G-308A promoter polymorphism and high-fasting plasma glucose levels, using multiple linear regression analysis with adjustment for the subjects' age, sex, body mass index and diabetic status, were found. Our results suggested that though TNF-alpha G-238A and G-308A polymorphisms were not involved in the pathogenesis of type 2 DM, type 2 diabetic patients carrying TNFA-A or TNF-308*2 genotype might be more susceptible to diabetic complications such as atherosclerosis.
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PMID:TNF-alpha polymorphisms and type 2 diabetes mellitus in Taiwanese patients. 1275 58

Tumor necrosis factor-alpha in low doses activated rat peritoneal macrophages and intensified production of reactive oxygen species (zymosan-depended chemiluminescence). Single or 2-fold incubation with tumor necrosis factor-a activated and preactivated human blood macrophages and promoted oxidative modification of low-density lipoproteins (increased their mobility in agarose gel). Antioxidants (potassium phenosan, probucol, and desferal) suppressed oxidative modification of low-density lipoproteins induced by nonactivated, preactivated, and activated macrophages. Our results show that antioxidants hold much promise for the prevention and therapy of atherosclerosis.
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PMID:Tumor necrosis factor-alpha in low doses preactivates and activates macrophages by increasing their ability to produce reactive oxygen species and oxidize low-density lipoproteins: protective effect of antioxidants. 1291 Mar 6

Tumor necrosis factor (TNF) is an important cytokine in the inflammation process of atherosclerosis. Two biallelic polymorphisms in the TNF-alpha (TNF-alpha -308) and TNF-beta (TNF-beta +252) genes have been reported to be associated with TNF production and susceptibility to inflammatory diseases. We investigated two genetic polymorphisms in the TNF locus (TNF-alpha -308 G-->A and TNF-beta +252 A-->G) as risk factors for cerebral infarction (CI) by determining its prevalence in 294 survivors of CI, and in 581 age-, gender-, and race-matched controls. A significant association was found for the TNF-alpha and TNF-beta genotypes in CI patients compared with controls. A significant increase was found for the TNF-alpha A allele in controls compared with CI patients (chi2 = 7.593, p = 0.006, odds ratio = 1.74, confidence interval = 1.17-2.59). In addition, the TNF-alpha GG genotype increased the relative risk for CI in subjects with the TNF-beta AA genotype (chi2 = 4.998, p = 0.025). As a result, compared to controls, the frequency of the TNF-alpha AA genotype was decreased, whereas that of TNF-beta AA was increased in CI patients. The former implies an association with resistance, whereas the latter suggests an association with susceptibility to the disease. These results show that the TNF-alpha -308 and TNF-beta +252 locus plays an important role in the etiopathogenesis of CI.
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PMID:TNF-alpha and TNF-beta gene polymorphisms in cerebral infarction. 1459 15


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