Involvement Of Lipopolysaccharide Research Articles

The inhibitory effect of RADKPS on pyroptosis of nucleus pulposus-derived mesenchymal stem cells.

IIntervertebral disc(IVD) degeneration(IDD)is a primary cause of low back pain(LBP)in people, which is associated with nucleus pulposus-derived mesenchymal stem cells(NPMSCs). In this study, the involvement of lipopolysaccharide(LPS) in the pyroptosis of NPMSCs was investigated, The effect of RADKPS on the pyroptosis of NPMSCs and the underlying mechanism behind the impact of RADKPS on the proliferative capacity of NPMSCs were also studied.Pyroptosis of NPMSCs was induced with 10 μg/ml LPS and its effects on the downstream signaling pathways were explored. The protective effect of RADKPS on NPMSCs under the action of LPS and its possible mechanism were explored. Usinng different techniques such as immunohistochemical analysis, cell proliferation assay, qPCR, and Western blot analysis. Accordingly, Caspase1/p20/p10, a protein associated with pyroptosis, was found to be over-expressed in LPS-challenged NPMSCs, Furthermore, the qPCR results demonstrated that LPS promoted the expression of pyroptosis-related gene IL-1β(P<0.0001) ,while down-regulated the expression of sox-9(p<0.001),which was a gene associated with the extracellular matrix(ECM). The immunohistochemical results identified lowered ERK1/2 expression and phosphorylated (p-)ERK1/2 in the degenerated IVD tissues. In this study, the influence of RADKPS on the proliferative ability of NPMSCs was evaluated using two-dimensional and three-dimensional cultures. It was noted that RADKPS promoted the proliferation of NPMSCs in the two-dimensional and three-dimensional cultures. The findings of the western blot experiments revealed that RADKPS inhibited the expression of pyroptosis-related proteins, while it upregulated the p-ERK1/2 (p < 0.001), RhoA (p < 0.01), collagen II (p < 0.01), and sox-9 (p < 0.01), while ERK inhibitor PD98059 and RhoA signaling pathway inhibitor CCG-1423 inhibited their expression.These findings reveal to us that RADKPS hydrogel may protect NPMSCs from pyroptosis. It was also noted that cell proliferation-related signaling pathways may promote the proliferation of NPMSCs. The results revealed that RADKPS hydrogel could be used as a potential therapeutic approach for IDD.

The role of lipopolisaccharide and antibodies to the lipopolysaccharide in the systemic circulation to the cardiovascular risk group determination

Abstract The inflammatory concept of atherogenesis is the leading one. Its finds development in the endotoxin theory of atherosclerosis, confirmed by numerous experimental studies and a several of clinical observations. But the involvement of lipopolysaccharide (LPS) in atherogenesis in humans has been studied without assessing the morphological changes in the structure of the vascular wall and not included an antibodies response. Existing scales for assessing the risk of developing cardiovascular diseases have a maximum error for patients with an average level risk. We examined 113 patients belonging to one group of cardiovascular risk (&amp;lt;5% on the SCORE scale). We evaluated such indicators, which can be attribution to risk factors and can be application in practice, as the level of LPS in blood plasma, the level of antibodies to the LPS Salmonella minnnesota RE 595 (AB-LPS-1) and LPS Escherichia coli O55 (AB-LPS-2) in serum. A duplex scanning of extracranial brachiocephalic arteries (BCA) and a testing for lipid profile were made. It was revealed that the lipid profile do not allow to evaluate the condition of the BCA wall prior duplex scanning. A significant difference was found in the concentration and frequency of occurrence of LPS and AB-LPS indicators among patients with varying degrees of severity of atherosclerotic lesions of BCA (table). Thus, the inclusion of as risk factors the level of LPS, the concentration of AB-LPS can help in predicting the condition of the carotid arteries wall and, accordingly, in changing the degree of risk in patients at the primary diagnosis level without the participation of high-tech expensive imaging techniques. Simple binary models with high specificity and sensitivity were constructed using cluster analysis to predict the severity of BCA atherosclerosis using concentration of LPS and AB-LPS adapted for practical (figure). Comparison risk factors between groups Parameter Group (by arterial wall state) p-value Intact wall Thickening of TIM ASP Cholesterol, mmol/L 6.43 [6.04; 6.82] 5.81 [4.75; 8.28] 6.63 [5.68; 7.51] 0.2750 LDL, mmol/L 4.43 [4.03; 4.78] 3.64 [3.04; 4.98] 4.74 [3.74; 5.28] 0.0558 HDL, mmol/L 1.09 [0.94; 1.29] 1.21 [1.07; 1.51] 1.13 [0.98; 1.35] 0.3198 Triglycerides, mmol/L 1.72 [1.23; 2.54] 1.21 [0.91; 1.92] 1.48 [0.99; 2.07] 0.2752 Atherogenicity index 4.23 [3.45; 6.32] 3.67 [2.91; 4.48] 4.93 [3.92; 5.68] 0.3532 LPS, EU/ml 0.90 [0.60; 1.52] 0.60 [0.41; 0.98]* 1.20 [0.60; 1.8]* 0.0067* AB-LPS-1, c.o.u.d. 216.0 [132.5; 248.5]* 127.5 [105.75; 221.5] 123.0 [91.00; 187.0]* 0.0444* AB-LPS-2, c.o.u.d. 374.0 [199.0; 481.0] 399.5 [195.75; 451.0] 265.0 [200.0; 399.0] 0.1991 *Result was significant at p&amp;lt;0.05 at post-hoc pairwise comparisons. “Decision tree” for a group of patients Funding Acknowledgement Type of funding source: None

Prognostic Importance of Systemic Endotoxinemia Indicators in Atherogenesis

Numerous studies have indicated a close relationship between lipid metabolism disorders and the inflammatory component of atherogenesis. Excess endotoxin (ET) in the general circulation can induce chronic inflammation, and its role in atherogenesis is difficult to overestimate. The involvement of lipopolysaccharide (LPS) in atherogenesis in humans has been studied without assessing the morphological changes in the structure of the vascular wall. It seemed therefore of importance to study the dynamics of the systemic endotoxinemia (SEE) parameters as probable markers of atherosclerosis in association with a progression of morphological changes in the arterial wall. A total of 104 volunteers were examined. The patients had lipid profile abnormalities without clinical manifestations of atherosclerosis, reported themselves to be healthy, and belonged to the moderate risk category (2–4%) on the SCORE scale. A Control group (n = 9) comparable the patients by sex and age. All subjects underwent a duplex scanning of extracranial brachiocephalic arteries (BCA) and a venous blood testing for lipid profile and SEE parameters, including ET, antibodies to the hydrophobic and hydrophilic part of the LPS molecule, and their concentration ratio. The patients were divided into three groups based on the structural changes detected in the arterial wall by ultrasound testing: no morphological change in the BCA (Normal), a thickening of the intima–media complex (TIM), and identified atherosclerotic plaque (ASP). Patients of the ASP group have a significantly higher ET concentration and a reduced activity of anti-ET immunity (AEI) as compared with the accepted reference values and values observed in the TIM group. ET level was not increased, but the AEI activity was reduced in the TIM group, as well as in the Control group. All SEE parameters were within their normal ranges in the Normal group. The main risk factors in assessing the risk for detecting atherosclerotic plaque of the BCA were an age over 55 years and a decrease in antibodies to the hydrophobic part of the LPS molecule below 163 c. u. o. d. Significant differences observed in SEE parameters between patient groups made it possible to assume that an increase in blood LPS concentration and a decrease in AEI activity are risk factors for atherosclerosis.

Involvement of lipopolysaccharide in ovarian cystic follicles in dairy cow: Expressions of LPS receptors and steroidogenesis-related genes in follicular cells of cystic follicles

In ovarian cystic follicles, molecular changes in the growing follicle may have a local action and contribute to anovulation and cystic formation. One of the candidate molecules that affect the steroid and gonadotropin signaling systems of cystic follicles is lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria. To examine the molecular characteristics of bovine cystic follicles, we analyzed LPS concentration in follicular fluid of cystic follicles, and the expression of LPS receptors and steroidogenesis-related genes in granulosa and theca cells. Cystic follicles were categorized as estradiol (E2)-active (EACF) and E2-inactive cystic follicle (EICF). Overall, LPS concentration in follicular fluid of EACF and EICF was higher compared with healthy preovulatory follicles (POF). Expression of luteinizing hormone receptor (LHR) in granulosa and thecal cells was decreased in EACF and EICF compared with POF. Expression of CYP19 in granulosa cells of EACF and EICF was lower than POF. High expression of StAR in granulosa and thecal cells was observed in EICF. In granulosa cells, the expression of TLR4 and TLR2 mRNA was higher in EICF than other follicles. By contrast, higher expression of TLR2 in thecal cells was observed in EICF. Thus, high LPS concentration in follicular fluid of cystic follicles may be associated with the regulation of expression of steroidogenesis-related genes in granulosa and theca cells. These finding revealed the molecular characteristics of bovine ovarian cysts and possible involvement of LPS in the pathology of cystic follicle diseases.

Acute induction of anomalous and amyloidogenic blood clotting by molecular amplification of highly substoichiometric levels of bacterial lipopolysaccharide

It is well known that a variety of inflammatory diseases are accompanied by hypercoagulability, and a number of more-or-less longer-term signalling pathways have been shown to be involved. In recent work, we have suggested a direct and primary role for bacterial lipopolysaccharide (LPS) in this hypercoagulability, but it seems never to have been tested directly. Here, we show that the addition of tiny concentrations (0.2 ng l−1) of bacterial LPS to both whole blood and platelet-poor plasma of normal, healthy donors leads to marked changes in the nature of the fibrin fibres so formed, as observed by ultrastructural and fluorescence microscopy (the latter implying that the fibrin is actually in an amyloid β-sheet-rich form that on stoichiometric grounds must occur autocatalytically). They resemble those seen in a number of inflammatory (and also amyloid) diseases, consistent with an involvement of LPS in their aetiology. These changes are mirrored by changes in their viscoelastic properties as measured by thromboelastography. As the terminal stages of coagulation involve the polymerization of fibrinogen into fibrin fibres, we tested whether LPS would bind to fibrinogen directly. We demonstrated this using isothermal calorimetry. Finally, we show that these changes in fibre structure are mirrored when the experiment is done simply with purified fibrinogen and thrombin (±0.2 ng l−1 LPS). This ratio of concentrations of LPS : fibrinogen in vivo represents a molecular amplification by the LPS of more than 108-fold, a number that is probably unparalleled in biology. The observation of a direct effect of such highly substoichiometric amounts of LPS on both fibrinogen and coagulation can account for the role of very small numbers of dormant bacteria in disease progression in a great many inflammatory conditions, and opens up this process to further mechanistic analysis and possible treatment.

Non-typhoidal Salmonella encephalopathy involving lipopolysaccharide in cattle

This study assessed the involvement of lipopolysaccharide (LPS) in the non-typhoidal Salmonella encephalopathy (NTSE) caused by a unique isolate of Salmonella enterica serovar Saint-paul (SstpNPG). NTSE was prevented by genetic (deletion of murE) or pharmacologic (polymyxin) disruption of LPS on SstpNPG although the disruption of LPS did not deter brain penetration of the strain. This is the first study to demonstrate that LPS is involved in the manifestations of NTSE.

Detailed characterization of the lipid A fraction from the nonpathogen Acinetobacter radioresistens strain S13

The genus Acinetobacter is composed of ubiquitous, generally nonpathogen environmental bacteria. Interest concerning these microorganisms has increased during the last 30 years, because some strains, belonging to the so-called A. baumannii-A. calcoaceticus complex, have been implicated in some severe pathological states in debilitated and hospitalized patients. The involvement of lipopolysaccharides (LPSs) as virulence factors in infections by Acinetobacter has been proven, and ongoing studies are aimed toward the complete serological characterization of the O-polysaccharides from LPSs isolated in clinical samples. Conversely, no characterization of the lipid A fraction from Acinetobacter strains has been performed. Here, the detailed structure of the lipid A fraction from A. radioresistens S13 is reported for the first time. A. radioresistens strains have never been isolated in cases of infectious disease. Nevertheless, it is known that the lipid A structure, with minor variations, is highly conserved across the genus; thus, structural details acquired from studies of this nonpathogen strain represent a useful basis for further studies of pathogen species.

Binding of Actinobacillus pleuropneumoniae lipopolysaccharides to glycosphingolipids evaluated by thin-layer chromatography.

The binding profile of Actinobacillus pleuropneumoniae serotypes 1 and 2 to various glycosphingolipids was evaluated by using thin-layer chromatogram overlay. A. pleuropneumoniae whole cells recognized glucosylceramide (Glcbeta1Cer), galactosylceramide (Galbeta1Cer) with hydroxy and nonhydroxy fatty acids, sulfatide (SO(3)-3Galbeta1Cer), lactosylceramide (Galbeta1-4Glcbeta1Cer), gangliotriaosylceramide GgO3 (GalNAcbeta1-4Galbeta1-4Glcbeta1Cer), and gangliotetraosylceramide GgO4 (Galbeta1-3GalNAcbeta1-4Galbeta1-4Glcbeta1Cer) glycosphingolipids. We observed no binding to globoseries, globotriaosylceramide Gb3, globoside Gb4, or Forssman Gb5 glycosphingolipids or to gangliosides GM1, GM2, GM3, GD1a, GD1b, GD3, and GT1b. The A. pleuropneumoniae strains tested also failed to detect phosphatidylethanolamine or ceramide. Interestingly, extracted lipopolysaccharide (LPS) of serotype 1 and serotype 2 as well as detoxified LPS of serotype 1 showed binding patterns similar to that of whole bacterial cells. Binding to GlcCer, GalCer, sulfatide, and LacCer, but not to GgO3 and GgO4 glycosphingolipids, was inhibited after incubation of the bacteria with monoclonal antibodies against LPS O antigen. These findings indicate the involvement of LPS in recognition of three groups of glycosphingolipids: (i) GlcCer and LacCer, where glucose is probably an important saccharide sequence required for LPS binding; (ii) GalCer and sulfatide glycosphingolipids, where the sulfate group is part of the binding epitope of the isoreceptor; and (iii) GgO3 and GgO4, where GalNacbeta1-4Gal disaccharide represents the minimal common binding epitope. Taken together, our results indicate that A. pleuropneumoniae LPS recognize various saccharide sequences found in different glycosphingolipids, which probably represents a strong virulence attribute.

Induction of Systemic Resistance Against Fusarium Wilt of Radish by Lipopolysaccharides ofPseudomonas fluorescens

In commercial greenhouse trials, Pseudomonas fluorescens strain WCS374 suppressed Fusarium wilt and increased radish yield. In bioassays, the involvement of lipopolysaccharides (LPSs) in induction of systemic resistance was studied. Induction of systemic resistance by selected plant growth-promoting rhizobacteria (PGPR) strains of P. fluorescens was involved in the suppression of Fusarium wilt of radish in a special rockwool bioassay. In this bioassay, the pathogen, Fusarium oxysporum f. sp. raphani, and the PGPR strain were inoculated at spatially separate locations on the plant root and were confined to these locations throughout the experiments. PGPR strains WCS374 and WCS417 of P. fluorescens and their crude cell wall extracts, which contained the LPS or purified LPS (consisting of lipid A/innercore/O-antigen side chain), induced systemic resistance, whereas P putida WCS358 or its crude or purified LPS did not. Neither the phage-resistant mutants of WCS374 and WCS417 lacking the O-antigenic side chain of the LPS nor the crude or purified lipid A/innercore of these mutants reduced disease incidence in this experimental design. Strain WCS374, but not its O-antigen-minus mutant, also induced systemic resistance when applied on the cotyledon of radish on an agar disk cut from a plate culture. The pathogen was delivered on the root in peat 2 days later. Thus, the resistance-inducing O-antigen of strain WCS374 was effective not only onto the root, but also on the cotyledon. In a bioassay with greenhouse soil naturally infested with the Fusarium wilt pathogen of radish, strain WCS374, but not the O-antigen-minus mutant, suppressed disease. This suggests the involvement of induced resistance in natural soil bioassays and commercial greenhouse trials.

Effects of lipopolysaccharide on hypothalamic-pituitary-adrenal axis in vitro

The possible involvement of lipopolysaccharide (LPS) and interleukin-1β (IL-1β) and their eventual interplay in CRH and ACTH release from cultured hypothalamic and pituitary cells respectively, have been studied. IL-1β was able to activate the hypothalamo-pituitary-adrenal axis at both hypothalamic and pituitary sites; LPS showed no direct action at hypothalamic level but it was able to inhibit basal and IL-1β-induced ACTH release: this could be responsible for a blunting of the adrenal cortex response that normally occurs in septic shock syndrome.

Involvement of lipopolysaccharide in the secretion of Escherichia coli alpha-haemolysin and Erwinia chrysanthemi proteases.

The presence of the alpha-haemolysin secretion genes sensitizes Escherichia coli to vancomycin, a glycopeptide antibiotic that is normally excluded from the Gram-negative envelope (owing to its large size) (M(r) 1400). The selection of vancomycin mutants in strains carrying such genes was found to be a very powerful method for selecting non-haemolytic mutants. In this way, mutations in the known secretion genes, hlyB, hlyD and tolC, were obtained. However additional mutations mapped in genes rfaH and galU which are required for lipopolysaccharide (LPS) biosynthesis. Mutations in rfaH and galU strongly reduced alpha-haemolysin secretion as well as the secretion of Erwinia chrysanthemi proteases in E. coli without affecting their synthesis. These mutations markedly lowered the content of TolC protein, required for haemolysin secretion and also of the PrtF protein necessary for protease secretion. These results raise the possibility that LPS is involved in the correct incorporation of the TolC and PrtF proteins into the cell envelope.

Role of outer membrane components in the nonspecific binding ofEscherichia coli to cellulose

The involvement of lipopolysaccharide and outer membrane proteins in the binding ofEscherichia coli to cellulose was investigated. Cellulose binding was assayed in defined strains with or without O-antigenic polysaccharide and in mutants with defects in lipopolysaccharide core synthesis. Binding was also tested in strains lacking major outer membrane proteins. Optimal cellulose binding was exhibited by rough strains and was reduced to various extents in the presence of different O-antigens. Core defects also reduced but did not abolish binding to cellulose. Reduced binding was also found in mutants lacking OmpC protein, but OmpC/OmpA double mutants orompB mutants lacking OmpC and OmpF were not affected. Mutants with reduced cellulose binding were also isolated directly through selection of nonbinding populations after chromatography on cellulose columns. Each of the independent isolates derived fromE. coli K12 with reduced cellulose binding had multiple mutations, with additional phenotypic changes such as phage resistance, increased sensitivity to bile salts, or altered patterns of outer membrane proteins. These results suggest that no single receptor that could be altered by mutation was responsible for the binding ofE. coli to cellulose. Rather, the nonspecific binding of cellulose was more likely to be due to interaction with, or the combined activity of, several integral outer membrane components that could be masked by O-antigen.

Involvement of lipopolysaccharide in the pathogenicity of Treponema hyodysenteriae.

Treponema hyodysenteriae, the etiologic agent of swine dysentery, caused gross and microscopic lesions in the large intestines of C3HeB/FeJ mice. No gross lesions were observed in the intestines of the closely related, but lipopolysaccharide-resistant, C3H/HeJ strain of mice, and microscopic lesions were mild, if present at all. In the presence of actinomycin D, 1 mg of T. hyodysenteriae lipopolysaccharide (LPS) was lethal for C3HeB/FeJ but not for C3H/HeJ mice. Also, the treponemal LPS was chemotactic for macrophages from C3H/HeJ mice but not for macrophages from C3HeB/FeJ mice. The difference between the two mouse strains in lesion development may be due to the nondestructive nature of LPS in C3H/HeJ mice, which suggests that the treponemal LPS is involved in the pathogenicity of T. hyodysenteriae. T. hyodysenteriae may prove to be a useful bacterium in the study of LPS-resistant C3H/HeJ mice, because resistance to the treponemal LPS and to the treponeme itself appear to correlate.