Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The finding of outer membrane protein I (OprI) of Pseudomonas aeruginosa in hemodialyzers used by patients with end-stage renal failure led us to study the possible role of OprI as cytokine inducer. However, there are few reports on the biological activity of OprI, because it is difficult to obtain highly purified OprI. In this study, we attempt to establish a procedure for the efficient purification of OprI, which does not include lipopolysaccharide, from the bacterial culture broth, not hemodialyzers, to demonstrate that OprI is a potent cytokine inducer. From bacterial culture broth (1 liter), P. aeruginosa PAO1, which was confirmed previously by the sequence coding, was separated by centrifugation, high-performance liquid chromatography, and disk electrophoresis. Mouse bone marrow cells were stimulated by purified OprI, and the supernatants of the culture were analyzed by several enzyme-linked immunosorbent assay kits. The tumor necrosis factor alpha production stimulated by purified OprI was confirmed and degraded within 24 h. Furthermore, interleukin (IL) 1alpha, IL-1beta, IL-6, and granulocyte-macrophage colony-stimulating factor were also induced by OprI despite the absence of lipopolysaccharide. We conclude that OprI has the potential to induce tumor necrosis factor alpha production in mouse bone marrow cells and that tumor necrosis factor alpha contributes to the induction of inflammatory cytokines, namely IL-1alpha, IL-1beta, IL-6, and granulocyte/macrophage colony-stimulating factor, while lipopolysaccharide has little effect on these cells. These results suggest the presence of a pathway of inflammatory signal transduction triggered by OprI. In addition, OprI is possibly one of the harmful dialysate pollutants in hemodialysis patients besides the well-known lipopolysaccharide.
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PMID:The outer membrane protein I of Pseudomonas aeruginosa PAO1, a possible pollutant of dialysate in hemodialysis, induces cytokines in mouse bone marrow cells. 1045 34

This paper is a review of three topics related to bio-trace metals. First, the transfer of metals into tissues of patients with chronic diseases treated with hemodialysis is examined. Such diseases include chronic hepatitis, diabetes, and chronic renal failure. In these diseases, metal contents from fingernails were flexible but non-specific. Toxicity may appear as the amount of heavy metals in tissues of patients with chronic renal failure treated with hemodialysis. For example, cadmium and lead were not excreted from the blood of patients during the hemodialysis treatment, and, therefore, their amounts gradually increased in the blood of patients. The level of zinc increased and was excreted in the urine of diabetic patients and experimental animals. Calcium accumulated in the kidney of streptozotocin (STZ)-induced diabetic rats that were fed low zinc diets; and, as a result, severe renal failure occurred. From these results, complication syndromes of either metal deficiency or excesses may occur in tissues of patients with chronic diseases. Second, the role of metallothionein (MT), an inducible protein, and the properties of MT isoforms have been studied on experimental animals. In the exocrine cells of the pancreas, MT was induced by various stresses such as zinc, STZ, alloxan and 4-aminopyrazolo-(3,4-d) pyrimidine, but the effects of those stresses were not clear in the endocrine cells. Therefore, MT may have a role in the exocrine cells of the pancreas. In addition, we were able to separate completely MT-1 and MT-2 isoforms in cytosol fractions of tissues using a capillary zone electrophoresis system at neutral pH without any detergents. Each role of the MT isoforms in the tissues soon started to become clear. Third, cisplatin, a platinum-containing anti-tumor drug, did not penetrate into the brain tissue under physiological conditions, as there is a blood-brain barrier to cerebral tissues; however, it did penetrate with either short-term hypoxia or in the case of lipopolysaccharide-treated experimental animals. Nitric oxide, prostaglandin, and free radicals are related to the penetration. Older rats had a higher sensitivity to cisplatin than younger rats.
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PMID:[Studies of metals and metallothionein in tissue]. 1072 70

Patients with chronic renal failure show an immunodeficiency characterized by frequent infectious complications and a low response to vaccinations. This is paralleled in vitro by a low T-cell proliferation on mitogenic stimuli because of an impaired costimulation by accessory cells. Furthermore, alterations of the cytokine profile are correlated with impaired immune function. The immune system is influenced by both uremia and renal replacement therapy. To evaluate the influence of hemodialysis on immune parameters, we studied patients before and after the initiation of chronic hemodialysis therapy. Fourteen patients with end-stage renal failure were tested before dialysis initiation and during the first 6 weeks of hemodialysis treatment. We determined the in vitro T-cell proliferation, as well as plasma levels of interleukin-6 (IL-6) and the release of IL-6 and IL-10 into culture supernatant poststimulation with lipopolysaccharide. After 6 weeks of intermittent hemodialysis, in vitro T-cell proliferation on stimulation improved significantly (stimulation index, 21.6 +/- 18.5 versus 58.1 +/- 45.5; P < 0.01). This improvement occurred regardless of whether synthetic dialyzers or cellulosic membranes were used for the initiation of dialysis. Plasma IL-6 levels, as well as IL-6 and IL-10 secretion, did not change during the study period. In patients with end-stage renal disease, the initiation of hemodialysis led to a significant improvement of in vitro T-cell proliferation. This effect may have a role for an improvement of immune function in vivo. The expected normalization of IL-6 and IL-10 production may be masked by cytokine induction through hemodialysis membranes.
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PMID:Initiation of hemodialysis treatment leads to improvement of T-cell activation in patients with end-stage renal disease. 1073 80

The pathogenesis of sepsis-induced renal failure is multifactorial and only partially understood. In these studies we evaluated intrarenal microcirculatory changes during endotoxemia and the potential role of nitric oxide (NO) and endothelin in these changes. In anesthetized rats endotoxin infusion [lipopolysaccharide (LPS), Escherichia coli serotype 0127:B8; 10 mg/kg/h] resulted in hypotension and a transient enhancement of renal blood flow, with cortical vasodilation and a loss of outer medullary vasodilatory response to hypotension. The initial cortical vasodilation was abolished by the NO synthase inhibitor NG-nitro-L-arginine methyl ester, but not by indomethacin. Direct NO measurements disclosed a gradual rise in cortical NO, despite the waning vasodilatory effect, suggesting antagonizing vasoconstrictive stimuli. In rats pretreated by LPS (1 mg/kg i.p. 1 day earlier) the renal blood flow was reduced to 55% of that of controls. Moreover, the vasodilatory response to LPS infusion was converted into profound cortical and medullary vasoconstriction. In these preconditioned rats the endothelin receptor antagonist bosentan evoked a vasodilatory response and attenuated the vasoconstrictive reaction to LPS infusion. The infusion of another LPS (E. coli serotype 0111:B4) exerted predominant and protracted renal vasodilation without hypotension. In conclusion, different LPS exert diverse systemic and renal hemodynamic responses. The 0127:B8 serotype attenuates renal medullary vasodilation during hypotension, exerts transient cortical vasodilation, and following repeated exposure induces profound renal vasoconstriction. NO and endothelin participate in LPS-induced vascular responses that may predispose to hypoxic tubular damage.
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PMID:Endotoxin-induced renal failure. I. A role for altered renal microcirculation. 1094 Jul 26

Acute endotoxemic renal failure involves renal vasoconstriction, which presumably occurs despite increased nitric oxide (NO) generation by inducible NO synthase in the kidney. The present study examined the hypothesis that the renal vasoconstriction during endotoxemia occurs in part because of desensitization of soluble guanylate cyclase (sGC). Endotoxic shock was induced in male B6/129F2/J mice by an intraperitoneal injection of Escherichia coli lipopolysaccharide. The endotoxemia resulted in shock and renal failure as evidenced by a decrease in mean arterial pressure and an increase in serum creatinine and urea nitrogen. Serum NO increased in a time-dependent manner, reaching the highest levels at 24 h, in parallel with induction of inducible NO synthase protein in the renal cortex. In renal cortical slices obtained from endotoxemic mice, cyclic guanosine monophosphate (cGMP) increased significantly at 6 h and 15 h as compared with control but normalized at 24 h after injection of lipopolysaccharide. Incubation of renal cortical slices in the presence of a phosphodiesterase inhibitor isobutylmethylxantine did not alter the pattern of changes in cGMP. Incubation of renal cortical slices with 2 mM sodium nitroprusside resulted in a similar accumulation of cGMP in slices taken from control and endotoxemic mice at 6 h and 15 h. However, in slices from 24-h endotoxemic mice, accumulation of cGMP in response to sodium nitroprusside was significantly lower. This lower stimulability of sGC was not paralleled by a decrease in its abundance in renal cortex on immunoblot. Taken together, these results demonstrate a desensitization of sGC in renal cortex during endotoxemia, which may contribute to the associated renal vasoconstriction.
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PMID:Desensitization of soluble guanylate cyclase in renal cortex during endotoxemia in mice. 1105 91

Spontaneous bacterial peritonitis (SBP) is a common complication of cirrhotic patients with ascites that usually results in renal failure and death despite the efficacy of the current antibiotic therapy. The pathogenesis of these phenomena is poorly known but it has been related to the production of vasoactive cell mediators locally acting on the splanchnic vasculature. Because previous studies showed that peritoneal macrophages of cirrhotic patients may produce high quantities of vascular endothelial growth factor (VEGF), a powerful vessel permeabilizing agent, when stimulated by cytokines and bacterial lipopolysaccharide, the present study was aimed to seek whether peritoneal macrophages of SBP patients are induced to produce increased amounts of VEGF. Our results indicate that the production rate and the messenger RNA (mRNA) and protein expression of this substance are increased in macrophages of patients with SBP in comparison with those of noninfected cirrhotic patients. This characteristic feature is absent in circulating monocytes of these patients. Moreover, enhanced endothelial cell proliferation induced by conditioned medium of macrophages isolated from the ascites of patients with SBP is abolished by anti-VEGF antibody, and peritoneal tissue of cirrhotic patients expresses both VEGF receptors, Flt-1 and KDR. These results, therefore, are consistent with the concept that locally released macrophage-derived VEGF may result in increased vascular permeability and plasma leakage in the peritoneal vessels of cirrhotic patients with SBP.
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PMID:Increased production of vascular endothelial growth factor in peritoneal macrophages of cirrhotic patients with spontaneous bacterial peritonitis. 1152 33

Nitric oxide (NO) is postulated to play a key role in the pathophysiology of renal failure in sepsis. Whether the renal effects of increased NO are beneficial or harmful remains unclear. In a porcine model of lipopolysaccharide (LPS)-induced shock, we evaluated the effect of LPS on glomerular filtration rate (GFR) and renal blood flow (RBF). We then administered the nonselective nitric oxide synthase (NOS) inhibitor N(G)-L-arginine methyl ester (L-NAME), and compared its effects on GFR and RBF with those of S-methylisothiourea (SMT), a selective NOS inhibitor, and those of saline. We postulated that SMT, by maintaining constitutive NO, would be more beneficial than either L-NAME or saline. LPS infusion decreased mean arterial pressure (MAP), and increased cardiac output, RBF, and medullary NO content. The increased RBF was diverted to the medulla. There was no evidence of renal dysfunction in the saline-resuscitated group. Both NOS inhibitors increased MAP but decreased RBF, but only L-NAME reduced GFR and increased sodium excretion and renal oxygen extraction. We conclude that NO in endotoxemia is beneficial because it maintains RBF and GFR. Additionally, selective NOS inhibition did not offer any advantages over saline resuscitation.
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PMID:Renal effects of nitric oxide in endotoxemia. 1173 42

In conscious, chronically instrumented rats we examined 1) renal tubular functional changes involved in lipopolysaccharide (LPS)-induced acute renal failure; 2) the effects of LPS on the expression of selected renal tubular water and sodium transporters; and 3) effects of milrinone, a phosphodiesterase type 3 (PDE3) inhibitor, and Ro-20-1724, a PDE4 inhibitor, on LPS-induced changes in renal function. Intravenous infusion of LPS (4 mg/kg b.wt. over 1 h) caused an immediate decrease in glomerular filtration rate (GFR) and proximal tubular outflow without changes in mean arterial pressure (MAP). LPS-induced fall in GFR and proximal tubular outflow were sustained on day 2. Furthermore, LPS-treated rats showed a marked increase in fractional distal water excretion, despite significantly elevated levels of plasma vasopressin (AVP). Semiquantitative immunoblotting showed that LPS increased the expression of the Na(+),K(+),2Cl(-)-cotransporter (BSC1) in the thick ascending limb, whereas the expression of the AVP-regulated water channel aquaporin-2 in the collecting duct (CD) was unchanged. Pretreatment with milrinone or Ro-20-1724 enhanced LPS-induced increases in plasma tumor necrosis factor-alpha and lactate, inhibited the LPS-induced tachycardia, and exacerbated the acute LPS-induced fall in GFR. Furthermore, Ro-20-1724-treated rats were unable to maintain MAP. We conclude 1) PDE3 or PDE4 inhibition exacerbates LPS-induced renal failure in conscious rats; and 2) LPS treated rats develop an escape from AVP in the CDs, which could be aimed to protect against water intoxication in septic conditions associated with decreased GFR and high levels of AVP.
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PMID:Lipopolysaccharide-induced acute renal failure in conscious rats: effects of specific phosphodiesterase type 3 and 4 inhibition. 1223 72

Nuclear factor kappa B (NF-kappaB), a pleiotropic transcriptional factor that promotes cell survival and protects cells from apoptosis, requires reduced thiols at critical steps in its activation pathway. Mercuric ion (Hg(2+)), one of the strongest thiol-binding agents known, impairs NF-kappaB activation and transcriptional activity in normal rat kidney epithelial (NRK52E) cells at concentrations as low as 0.5 microM by binding to specific reduced thiol moieties in the NF-kappaB activation pathway. We hypothesized that prevention of NF-kappaB activation by Hg(2+) will increase the sensitivity of kidney cells to the apoptosis-inducing effects of other toxicants to which these cells are otherwise resistant by virtue of their NF-kappaB-activating capacity. Fewer than 5% of untreated kidney cells in culture (70-90% confluent) were found to be apoptotic when evaluated by DNA fragmentation (terminal deoxynucleotide transferase-mediated dUTP nick-end labeling) or flow cytometric DNA profile analyses. Hg(2+) (5 microM) treatment for 24 hr increased this proportion by 1.5- to 2-fold. Neither lipopolysaccharide (LPS) (1 microg/mL) nor tumor necrosis factor-alpha (TNF-alpha; 300 U/mL), both potent activators of NF-kappaB in kidney cells, significantly altered the proportion of apoptotic cells, compared with untreated controls, when applied without Hg(2+) pretreatment. However, when LPS or TNF-alpha was administered after Hg(2+) pretreatment (5 microM for 30 min), the proportion of cells undergoing apoptosis 22 hr later increased by 4- to 6-fold compared with untreated controls. In contrast, Hg(2+) pretreatment did not increase the amount of apoptosis caused by apoptosis-inducing agents that do not activate NF-kappaB (staurosporine, Fas ligand). These findings suggest that Hg(2+) enhances the sensitivity of kidney cells to apoptotic stimuli as a consequence of inhibition of NF-kappaB activity. Because apoptosis is known to play a key role in the pathogenesis of renal failure resulting from toxicant injury to proximal tubular cells, promotion of apoptosis via inhibition of NF-kappaB activity may define a novel molecular mechanism by which Hg(2+) toxicity is initiated in kidney cells.
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PMID:Attenuation of nuclear factor kappa B (NF-kappaB) promotes apoptosis of kidney epithelial cells: a potential mechanism of mercury-induced nephrotoxicity. 1242 38

The bioartificial kidney (BAK) consists of a conventional hemofiltration cartridge in series with a renal tubule assist device (RAD) containing 10(9) porcine renal proximal tubule cells. BAK replaces filtration, transport, and metabolic and endocrinologic activities of a kidney. Previous work in an acutely uremic dog model demonstrated that BAK ameliorated endotoxin (lipopolysaccharide [LPS])-induced hypotension and altered plasma cytokine levels. To further assess the role of BAK in sepsis in acute renal failure, dogs were nephrectomized and 48 h later administered intraperitoneally with 30 x 10(10) bacteria/kg of E. coli. One hour after bacterial administration, animals were placed in a continuous venovenous hemofiltration circuit with either a sham RAD without cells (n = 6) or a RAD with cells (n = 6). BP, cardiac output, heart rate, pulmonary capillary wedge pressure, and systemic vascular resistance were measured throughout the study. All animals tested were in renal failure, with blood urea nitrogen and serum creatinine concentrations greater than 60 and 6 mg/dl, respectively. RAD treatment maintained significantly better cardiovascular performance, as determined by arterial BP (P < 0.05) and cardiac output (P < 0.02), for longer periods than sham RAD therapy. Consistently, all sham RAD-treated animals, except one, expired within 2 to 9 h after bacterial administration, whereas all RAD-treated animals survived more than 10 h. Plasma levels of TNF-alpha, IL-10, and C-reactive protein (CRP) were measured during cell RAD and sham RAD treatment. IL-10 levels were significantly higher (P < 0.01) during the entire treatment interval in the RAD animals compared with sham controls. These data demonstrated in a pilot large animal experiment that the BAK with RAD altered plasma cytokine levels in acutely uremic animals with septic shock. This change was associated with improved cardiovascular performance and increased survival time. These results demonstrate that the addition of cell therapy to hemofiltration in an acutely uremic animal model with septic shock ameliorates cardiovascular dysfunction, alters systemic cytokine balance, and improves survival time.
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PMID:Bioartificial kidney ameliorates gram-negative bacteria-induced septic shock in uremic animals. 1253 47


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