Biomedical subjects

S Barve

Publications and source records attributed to S Barve.

At least 19 recordsLinked to original sources

PubMed2005

Akt inhibition upregulates FasL, downregulates c-FLIPs and induces caspase-8-dependent cell death in Jurkat T lymphocytes.

In T lymphocytes, the role of Akt in regulating Fas/Fas ligand (FasL)-mediated apoptotic signaling and death is not clearly understood. In this study, we observed that inhibition of Akt causes enhanced expression of FasL mRNA and protein and increased death-inducing signaling complex (DISC) formation with Fas-associated death domain (FADD) and procaspase-8 recruitment. Also, caspase-8 was activated at the DISC with accompanying decrease in c-FLIPs expression. FasL neutralizing antibody significantly decreased apoptotic death in the Akt-inhibited T cells. Additionally, Akt inhibition-induced Fas signaling was observed to link to the mitochondrial pathway via Bid cleavage. Further, inhibition of caspase-8 activity effectively blocked the loss of mitochondrial membrane potential and DNA fragmentation, suggesting that DISC formation and subsequent caspase-8 activation are critical initiating events in Akt inhibition-induced apoptotic death in T lymphocytes. These data demonstrate yet another important survival function governed by Akt kinase in T lymphocytes, which involves the regulation of FasL expression and consequent apoptotic signaling.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Antioxidants inhibit cytokine production and suppress NF-kappaB activation in CAPAN-1 and CAPAN-2 cell lines.

Interleukin (IL) -6 and IL-8 are cytokines that have been shown to play a role in several pancreatic diseases, including acute pancreatitis, chronic pancreatitis, and pancreatic adenocarcinoma. Previously, we have demonstrated that tumor necrosis factor-alpha (TNF-alpha) and gram-negative bacterial lipopolysaccharide stimulate production of IL-6 and IL-8 and activation of the transcription factor NF-kappaB in the well-differentiated pancreatic ductal adenocarcinoma cell lines CAPAN-1 and CAPAN-2. In these studies we have examined the effect of chain-breaking and glutathione-enhancing antioxidants on NF-kappaB activation and production of IL-6 and IL-8 in these cell lines. Generally, suppression of NF-kappaB activation correlated well with inhibition of IL-6 and IL-8 secretion. In the CAPAN-2 cell line, antioxidants inhibited both NF-kappaB activation and IL-6 and IL-8 secretion. In the CAPAN-1 cell line, antioxidants generally failed to suppress both NF-kappaB activation and IL-6 and IL-8 secretion. The single exception was the chain-breaking antioxidant butylated hydroxyanisole (BHA), which markedly inhibited IL-6 and IL-8 secretion, but had no effect on NF-kappaB activation. These findings may have implications for the treatment of acute and chronic pancreatitis and pancreatic cancer.

Adenocarcinoma↗

PubMed2001

How is the liver primed or sensitized for alcoholic liver disease?

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Hidekazu Tsukamoto and Yoshiyuki Takei. The presentations were (1) Tribute to Professor Rajendar K. Chawla, by Craig J. McClain; (2) Dysregulated TNF signaling in alcoholic liver disease, by Craig J. McClain, S. Joshi-Barve, D. Hill, J Schmidt, I. Deaciuc, and S. Barve; (3) The role of mitochondria in ethanol-mediated sensitization of the liver, by Anna Colell, Carmen Garcia-Ruiz, Neil Kaplowitz, and Jose C. Fernandez-Checa; (4) A peroxisome proliferator (bezafibrate) can prevent superoxide anion release into hepatic sinusoid after acute ethanol administration, by Hirokazu Yokoyama, Yukishige Okamura, Yuji Nakamura, and Hiromasa Ishii; (5) S-adenosylmethionine affects tumor necrosis factor-alpha gene expression in macrophages, by Rajendar K. Chawla, S. Barve, S. Joshi-Barve, W. Watson, W. Nelson, and C. McClain; (6) Iron, retinoic acid and hepatic macrophage TNFalpha gene expression in ALD, by Hidekazu Tsukamoto, Min Lin, Mitsuru Ohata, and Kenta Motomura; and (7) Role of Kupffer cells and gut-derived endotoxin in alcoholic liver injury, by N. Enomoto, K. Ikejima, T. Kitamura, H. Oide, Y. Takei, M. Hirose, B. U. Bradford, C. A. Rivera, H. Kono, S. Peter, S. Yamashina, A. Konno, M. Ishikawa, H. Shimizu, N. Sato, and R. Thurman.

Animals↗

PubMed2001

The green tea polyphenol (-)-epigallocatechin-3-gallate blocks nuclear factor-kappa B activation by inhibiting I kappa B kinase activity in the intestinal epithelial cell line IEC-6.

The I kappa B kinase complex (IKK) mediates activation of the transcription factor nuclear factor-kappa B (NF-kappa B). We previously showed that green tea polyphenols inhibited endotoxin-mediated tumor necrosis factor-alpha (TNF alpha) production by blocking NF-kappa B activation. In this study, we evaluated whether green tea polyphenols inhibit NF-kappa B by blocking IKK activity. We assessed IKK activity by detecting changes in phosphorylation of an I kappa B alpha-glutathione S-transferase (GST) fusion protein. IEC-6 cells pretreated with an extract of green tea polyphenols (GrTPs; 0--0.4 mg/ml) had diminished TNF alpha-induced IKK and NF-kappa B activity. Of the various GrTPs, (-)-epigallocatechin-3-gallate (EGCG) was the most potent inhibitor. We next examined whether EGCG inhibited activated IKK. In cytosolic extracts of TNF alpha-stimulated cells, EGCG inhibited phosphorylation of I kappa B alpha-GST (IC(50) > 18 microM) consistent with inhibition of IKK activity. Using other polyphenols, we showed that the gallate group was essential for inhibition, and antioxidants were ineffective in blocking activated IKK. Importantly, EGCG decreased IKK activity in cytosolic extracts of NIK transiently transfected cells. This latter finding showed that our findings were not related to nonspecific kinase activity. In conclusion, EGCG is an effective inhibitor of IKK activity. This may explain, at least in part, some of the reported anti-inflammatory and anticancer effects of green tea.

Animals↗

PubMed2000

Cytokine production by CAPAN-1 and CAPAN-2 cell lines.

Recently, there has been a great deal of interest in the role of cytokines in acute pancreatitis. Serum levels of IL-1, IL-6, and TNF-alpha have been demonstrated to be elevated in acute pancreatitis. We hypothesized that cytokines may be produced primarily by pancreatic parenchymal cells. Reasoning that ductal epithelium is the cell type most likely to be exposed to noxious stimuli in common causes of pancreatitis, such as ERCP and passage of a gallstone, we examined the response of well differentiated pancreatic ductal adenocarcinoma cell lines to stimuli known to stimulate cytokine production in other cells. CAPAN-1 and CAPAN-2 cells were incubated with endotoxin or TNF-alpha. The supernatant was assayed for production of IL-1, IL-6, and IL-8 by ELISA. The cells were assayed for activation of the transcription factor NF-kappaB by electrophoretic mobility shift assay. There was no detectable production of IL-1 by either cell line. CAPAN-1 cells had concentration-dependent production of IL-6 and IL-8 in response to both endotoxin and TNF-alpha. CAPAN-2 cells had concentration-dependent production of IL-6 and IL-8 in response to TNF-alpha. They had low level expression of IL-8 that was unaffected by any concentration of LPS, and no detectable production of IL-6 in response to LPS. These findings suggest that pancreatic duct cells may take an active part in the pathogenesis of acute pancreatitis through the production of cytokines.

Acute Disease↗

PubMed2000

Increased monocyte nuclear factor-kappaB activation and tumor necrosis factor production in alcoholic hepatitis.

Increased tumor necrosis factor-a activity has been reported in patients with alcoholic hepatitis and is implicated in its pathogenesis. The aim of this study was to investigate potential mechanisms of increased tumor necrosis factor-a activity in alcoholic hepatitis. Monocyte nuclear factor-kB activity was assessed by electrophoretic mobility shift assay, monocyte tumor necrosis factor-a mRNA was semi-quantitatively assessed by reverse transcriptase polymerase chain reaction, and tumor necrosis factor-a in monocyte culture supernatants was measured. There was significantly greater spontaneous nuclear factor-kB activity in the monocytes of 6 patients with alcoholic hepatitis as compared with that in the monocytes of control subjects. There was spontaneous tumor necrosis factor-a mRNA and tumor necrosis factor-a release from the monocytes of patients with alcoholic hepatitis but not from the monocytes of normal subjects. Endotoxin increased nuclear factor-kB activity and induced tumor necrosis factor-a mRNA and tumor necrosis factor-a release from normal subjects' monocytes. Endotoxin further increased nuclear factor-kB activity, tumor necrosis factor-a mRNA, and tumor necrosis factor-a release from the monocytes of patients with alcoholic hepatitis. Supershift assays indicate that the monocyte nuclear factor-kB activation involves the p50 and p65 subunits. Dysregulated tumor necrosis factor-a metabolism in alcoholic hepatitis monocytes is associated with increased nuclear factor-kB activity and tumor necrosis factor-a mRNA expression.

Adult↗

PubMed1999

Increased monocyte MCP-1 production in acute alcoholic hepatitis.

Monocyte chemoattractant protein-1 (MCP-1) is a potent mononuclear cell-specific chemotactic protein. MCP-1 is a candidate chemoattractant for activation and hepatic infiltration of mononuclear cells in alcoholic hepatitis (AH). Blood was collected from 15 patients with AH (mean bilirubin 17.6+/-3.5 mg/dl; normal 0. 2-1.0 mg/dl) on admission and at time points for up to 6 months. Peripheral blood monocytes were isolated and MCP-1 production assessed by measuring MCP-1 concentrations in monocyte culture supernatants after overnight (20 h) incubation. Monocytes from normal subjects did not product detectable MCP-1 unless stimulated with endotoxin (LPS;5 microg/ml). The mean level of constitutive MCP-1 from AH patient monocytes was 4694+/-2432 pg/ml 20 h on admission. The mean MCP-1 level for LPS-treated monocytes was 4903+/-1540 pg/ml 20 h for normal subjects and was significantly elevated in AH patients to 11589+/-3266 pg/ml/20 h. AH patient monocyte MCP-1 production was decreased in vitro when monocytes were treated with N-acetylcysteine (5 mM) and also decreased over the 6-month study as the patients improved clinically. MCP-1 plasma levels were below the detection limits of the assay used in both AH patients and normal subjects. Thus, monocytes from AH patients not only constitutively product MCP-1, but also produce higher levels of MCP-1 with endotoxin stimulation. Further studies are needed to clarify the role of MCP-1 in the activation and hepatic infiltration of mononuclear cells in alcoholic liver disease.

Acetylcysteine↗

PubMed1999

Antioxidants attenuate nuclear factor-kappa B activation and tumor necrosis factor-alpha production in alcoholic hepatitis patient monocytes and rat Kupffer cells, in vitro.

UNLABELLED: There is increased tumor necrosis factor-alpha (TNF) activity in alcoholic hepatitis (AH). OBJECTIVES: To examine the effects of antioxidants and glutathione enhancing agents on NF-kappaB activation and TNF production in Kupffer cells and monocytes. DESIGN AND METHODS: Isolated rat Kupffer cells and peripheral blood monocytes from AH patients were treated in vitro. NF-kappaB activation was assessed by electrophoretic mobility shift assay and TNF was measured in cell culture supernatants. RESULTS: Monocytes from AH patients had greater TNF production compared to normal volunteers. Pretreatment with antioxidants or gluathione enhancing agents inhibited TNF production and NF-kappaB activation in both monocytes from normal and AH patients as well as in rat Kupffer cells. CONCLUSIONS: There may be a therapeutic role for antioxidants or glutathione enhancing agents in disease states with increased TNF activity such as AH.

Animals↗

PubMed1999

Cytokines in alcoholic liver disease.

Cytokines are low-molecular-weight mediators of cellular communication produced by multiple cell types in the liver, with the Kupffer cell critically important. Inflammatory cytokines such as tumor necrosis factor, interleukin-1, and interleukin-8, and hepatic acute-phase cytokines such as interleukin-6 play a role in modulating certain metabolic complications in alcoholic liver disease and probably play a role in the liver injury of alcoholic liver disease. Two potential inducers of cytokine production in alcoholic liver disease are endotoxin and reactive oxygen species generated after ethanol metabolism. Cytotoxic cytokines likely induce liver cell death by both necrosis and apoptosis in alcoholic liver disease. Anticytokine therapy has been highly successful in attenuating cell injury/death in a variety of toxin-induced models of liver injury, including alcohol-related liver injury. Anticytokine therapy has been used successfully in humans in disease processes such as Crohn's disease and rheumatoid arthritis. There is an emerging rationale for use of anticytokine therapy in alcoholic liver disease, with the goal of maintaining beneficial effects of cytokines and inhibition of the deleterious effects of these potentially toxic agents.

Animals↗

PubMed1999

A high dose of ionizing radiation induces tissue-specific activation of nuclear factor-kappaB in vivo.

Activation of the transcription factor nuclear factor-kappaB (NF-kappaB) is one of the important responses of cells to an external stress such as ionizing radiation. We studied radiation-induced NF-kappaB activation in vivo in male BALB/c mice. After the mice were exposed to 8.5 Gy total-body gamma irradiation, the spleen, mesenteric lymph nodes, thymus, liver, lung, colon, brain and bone marrow were harvested 1, 2.5, 5, 10 and 20 h postirradiation. NF-kappaB DNA-binding activity was analyzed in the nuclear protein extracts by a gel shift assay. When compared to the levels in untreated control mice, radiation induced activation of NF-kappaB in spleen, mesenteric lymph nodes and bone marrow but not in the other tissues examined. In contrast, an i.p. injection of a lethal dose (3 mg/kg) of lipopolysaccharide also increased activity of NF-kappaB in the liver and lung. The gel supershift assay with Nfkb1, Rela and/or Rel antibodies revealed that the specific molecular forms of NF-kappaB activated by radiation in the spleen were Nfkb1 homodimers and Nfkb1/Rela heterodimers. In mesenteric lymph nodes, the heterodimerized Rel/Rela NF-kappaB was also activated. In bone marrow, an NF-kappaB-like binding factor was induced that may be Nfkb1/Rela- and Rel/Rela-like heterodimers, but it exhibited a higher mobility than Nfkb1 homodimers. These results indicate that in vivo, ionizing radiation induces NF-kappaB activation that varies in both tissue distribution and moleoular composition.

Animals↗

PubMed1998

Clinical predictors of outcome in hypoxic ischaemic encephalopathy in term neonates.

Thirty-eight full-term infants with hypoxic ischaemic encephalopathy were followed up prospectively to determine simple predictors of outcome at 1 year. Three predictors of outcome, based on clinical examination alone, were evaluated. These were presence of seizures, grading of encephalopathy and neurobehavioural assessment at discharge from the hospital. Development was assessed using the Bayley scales of infant development, and a mental and motor quotient below 85 was considered to be delayed development. At 1 year, 15 infants showed delayed development; five of them had cerebral palsy. Predictive values were determined for each indicator. Seizures per se did not affect the outcome. All infants with mild encephalopathy were normal. The predictive value of moderate-to-severe encephalopathy was 50%. Abnormal neurobehaviour at the age of 7 days or at discharge, if earlier, was found to be the best predictor of outcome with a predictive value of 91.6%.

Anticonvulsants↗

PubMed1998

Tumor necrosis factor and alcoholic liver disease.

Increased levels of hepatic and serum tumor necrosis factor (TNF) have been documented in animal models of alcoholic liver disease and in human alcoholic liver disease. This dysregulated TNF metabolism has been postulated to play a role in many of the metabolic complications and the liver injury of alcoholic liver disease. One potential therapy for alcoholic liver disease may be agents that downregulate TNF production or block TNF activity. Indeed, agents such as prostaglandins and glucocorticoids (both inhibit TNF production) have been used in both human liver disease and experimental models of liver injury, and anti-TNF antibody has recently been shown to attenuate the hepatotoxicity in an animal model of alcoholic-related liver disease. In this study, we demonstrate that a simple ex vivo system can be used to initially assess potential efficacy of anticytokine agents when administered to humans. Both prednisone and a prostaglandin analog were effective in downregulating TNF and interleukin-8 production. The liver is normally resistant to TNF cytotoxicity. Sensitivity to TNF cytotoxicity is thought to occur when there is inadequate production of hepatic protective factors. In this study, we showed that, when patients with acute alcoholic hepatitis were matched with trauma patients for serum levels of interleukin-6, they had similar depressions in the negative acute phase protein, albumin, but markedly different increases in the major acute phase protein, C reactive protein. Patients with alcoholic hepatitis had a very blunted response. We also showed that inhibiting activation of the redox sensitive transcription factor NFkappaB sensitizes to TNF-induced hepatocyte death in vitro. This transcription factor is important for the production of both cytokines and many acute phase protective factors. Several hepatic protective factors are induced by TNF. One possible mechanism for liver injury in alcoholic hepatitis may be inadequate generation of hepatic protective factors. Our future understanding of mechanisms of alcoholic liver disease will involve understanding the balance between noxious and protective factors in the liver, and this should lead to rational therapy for this disease process.

Animals↗

PubMed1998

Use of transfected liver cells to evaluate potential mechanisms of alcohol-induced liver injury.

There is increased activity of the proinflammatory cytokine, tumor necrosis factor (TNF) in alcoholic liver disease (ALD). Hepatic neutrophil infiltration is a principal injurious manifestation of ALD. TNF can induce cellular oxidative injury directly, and indirectly by inducing neutrophil chemotactic factor (IL-8) production by hepatocytes. IL-8 activates and chemotactically attracts neutrophils to the liver where they release oxidizing substances. Patients with ALD also have decreased protective factors for cellular oxidative injury. Manganous superoxide dismutase (MnSOD) is an antioxidant protective factor. The objectives of these studies were to investigate mechanisms for induction of an injurious factor (IL-8) and a protective factor (MnSOD) in the HepG2 human hepatoma cell line. In the first set of experiments, IL-8 gene reporter constructs were used to transiently transfect a derivative (MVh2E1-9) of the HepG2 cell line which expresses P-4502E1 and metabolizes ethanol. Inactivation of the NF-kappaB and 3'NF-IL-6 DNA binding sites decreased IL-8 gene transcriptional activation in response to TNF while inactivation of the 5'NF-IL-6 binding site increased IL-8 gene transcriptional activity in response to TNF. This system may be useful to assess the effects of ethanol on TNF-induced hepatocyte IL-8 production. In the second set of experiments, HepG2 cells were cultured in 25 to 100 mmol concentrations of ethanol. Both TNF and ethanol increased HepG2 cell MnSOD activity in short-term (72 hr) cultures with ethanol. However, after long-term (10 weeks) culture with ethanol, there was no induction of MnSOD by ethanol and there was a diminished induction of MnSOD in response to TNF. Further studies are needed to assess the effect of this diminished induction of MnSOD with chronic ethanol culture on HepG2 cell susceptibility to TNF cytotoxicity. We conclude that transfected liver cell lines can be used to evaluate mechanisms for increased injurious factors and decreased protective factors in alcoholic liver injury.

Animals↗

PubMed1997

Zinc attenuates tumor necrosis factor-mediated activation of transcription factors in endothelial cells.

OBJECTIVE: The objective of the study was to test the hypothesis that zinc can protect against endothelial dysfunction by interfering with oxidative stress-mediated cellular signaling and subsequent inhibition of an endothelial cell inflammatory response. Our approach was to compare alterations on molecular and biochemical levels with changes in endothelial barrier function that occur in zinc deficient conditions. METHODS: To investigate our hypothesis, endothelial cells were exposed to zinc deficient media for 2 to 10 days to deplete cellular zinc stores. Following this, half of the groups received zinc supplementation (9.2 microM) for 48 hours. The other half served as zinc deficient controls. These cells were then challenged with tumor necrosis factor-alpha (TNF) for varying time periods. Nuclear extracts were prepared from cells and analyzed for nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1) binding. Media from cells were analyzed for interleukin 8 (IL-8) production, and cellular proteins were determined. RESULTS: Zinc supplementation resulted in a 74% increase in cellular zinc content. It was also shown that a 1.5 hour exposure to TNF (100 U/mL medium) significantly increased NF-kappa B and AP-1 binding, which was lowered considerably when cells were supplemented with physiological levels of zinc. Zinc supplementation also caused a marked attenuation in IL-8 expression by endothelial cells in response to TNF-mediated cell activation. DISCUSSION: Our previous data clearly show that zinc is a protective and critical nutrient for maintenance of endothelial integrity. The present data suggest that zinc may protect against cytokine-mediated activation of oxidative stress sensitive transcription factors, upregulation of inflammatory cytokines and endothelial cell dysfunction. This may have implications in understanding mechanisms of atherosclerosis.

Animals↗

PubMed1997

Cytokines and alcoholic liver disease.

Chemical messengers called cytokines play an important role during the body's initial response to infection (i.e., acute inflammation). Cytokines attract and activate components of the immune system, promote blood clotting, and facilitate the release of additional chemical messengers. In addition, cytokines induce the liver to shift its physiological function, emphasizing inflammatory and immune responses at the expense of normal metabolism. Alcohol consumption may cause excessive cytokine production in the liver, leading to inflammatory liver disease. Researchers are seeking ways to moderate the toxic effects of cytokines while sparing their protective functions.

Animals↗

PubMed1997

Early predictors of neurodevelopmental outcome in high risk infants.

OBJECTIVE: To find out a few simple and easily elicitable items at three and six months of age that can predict neurodevelopmental outcome at one year in high risk babies. DESIGN: One year longitudinal follow up study. SETTING: Hospital based study including inborn and outborn infants discharged from the Neonatal Intensive Care Unit (NICU) of a referral hospital, followed up in a High Risk Clinic. METHODS: Sixty high risk babies were followed up longitudinally for a period of one year. A detailed neurodevelopmental examination was done with special attention to the following items-axillary suspension, head support, social smile, disappearance of primitive reflexes and neurobehavior at three months age while pull to sit, rolling over, sitting momentarily without support, transfer of objects and voluntary reach were evaluated at six months age. Bayley Scales of Infant Development (Baroda Norms) was used for assessing the outcome at one year. RESULTS: Babies with absence of social smile, abnormal neurobehavior at three months and absent pulling to sit position, absent voluntary reach, and absent transfer of objects, remained delayed at one year. The specificity of each of these items was 100%. These items had a positive predictive value of 100%. CONCLUSIONS: Inability to achieve social smile and abnormal neurobehavior at three months age and absence of pulling to sit position, transfer of objects and voluntary reach at six months age, warrant early intervention. These items are easy to elicit, do not require any special kit or elaborate training. Hence these items can be tested even by those working at the primary level or in office practice.

Adaptation, Physiological↗

PubMed1996

Linoleic acid activates nuclear transcription factor-kappa B (NF-kappa B) and induces NF-kappa B-dependent transcription in cultured endothelial cells.

High dietary intakes of unsaturated fats may be atherogenic by disrupting normal functions of the vascular endothelium, due in part to the ability of linoleic acid (18:2n-6) to contribute to an increase in cellular oxidative stress and related injurious events. Exposing endothelial cells to 90 micromol linoleic acid/L for 6 h resulted in a significant increase in lipid hydroperoxides that coincided wih an increase in intracellular calcium concentrations. Treatment with this fatty acid caused an initial decrease in glutathione concentrations, which was followed by an increase at later time points. Most importantly, a significant activation of the oxidative stress-sensitive nuclear transcription factor-kappa B (NF-kappa B) was achieved after a 6-h exposure to 18:2n-6, which is the time point at which maximal depletion of cellular glutathione was observed. The fatty acid-mediated NF-kappa B activation was accompanied by induction of NF-kappa B-dependent transcription, as measured by chloramphenicol acetyltransferase (CAT) assay of an NF-kappa B-responsive promoter construct. Pretreatment of endothelial cells with vitamin E and N-acetyl cysteine inhibited the fatty acid-induced activation of NF-kappa B and formation of lipid hydroperoxides. These data suggest that oxidative stress-induced cellular changes are critical early events in fatty acid-mediated endothelial cell dysfunction.

Animals↗

PubMed1996

Linoleic acid and TNF-alpha cross-amplify oxidative injury and dysfunction of endothelial cells.

Factors implicated in the development of atherosclerosis include metabolic alterations of the endothelium induced by certain lipids and inflammatory cytokines. To study the hypothesis that the combined presence of unsaturated fatty acids and inflammatory cytokines may cross-amplify their individual injurious effects, cultured endothelial cells were treated with 90 mu M of linoleic acid (18:2 n-6) and/or 20 ng/ml (100 U/ml) of tumor necrosis factor-alpha (TNF) for up to 24 h. Disturbances in endothelial cell metabolism were determined by measuring cellular oxidative stress, oxidative stress-inducible nuclear factor-kappa B (NF-kappa B) and NF-kappa B-related transcription, intracellular calcium levels, and endothelial barrier function reflected by transendothelial albumin movement. Both 18:2 and TNF increased cellular oxidation, intracellular calcium, and endothelial barrier permeability. These changes were cross-amplified in cells treated both with 18:2 and TNF, compared with 18:2 or TNF alone. In contrast, a combined exposure to 18:2 and TNF did not potentiate effects mediated by 18:2 or TNF alone on NF-kappa B activation or NF-kappa B-related transcription. Pretreatment with 25 mu M vitamin E attenuated 18:2 and/or TNF-mediated endothelial cell dysfunction. These results suggest that certain unsaturated fatty acids can potentiate TNF-mediated endothelial cell dysfunction and that oxidative stress may be partially responsible for these metabolic events. These findings have implications for understanding lipid-mediated inflammatory responses in atherosclerosis.

Animals↗