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Search Results: 1 - 10 of 266 matches for " lipopolysaccharide "
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Oronasal administration of lipopolysaccharide prepartum modulated plasma metabolite patterns in periparturient dairy cows  [PDF]
Summera Iqbal, Qendrim Zebeli, Dominik A. Mansmann, Suzanna M. Dunn, Burim N. Ametaj
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.33028

The objective of this study was to evaluate whether repeated oronasal administration of LPS before parturition showed effects on metabolic and clinical responses in periparturient dairy cows. Hundred Holstein dairy cows were randomly allocated to two treatment groups (n = 50). Thirty cows out of 100 were randomly assigned for intensive sampling (n = 15) started at 28 d before the expected day of parturition. Cows received an oral and a nasal treatment of 2 mL and 1 mL of sterile saline solution (0.15 M of NaCl), respectively, alone (control), or containing 3 increasing doses of LPS from Escherichia coli 0111:B4 as follows: 1) 0.01 μg/kg body weight (BW) on d ﹣28, 2) 0.05 μg/kg BW on d ﹣25, and ﹣21, and 3) 0.1 μg/kg BW on d ﹣18 and ﹣14. Blood samples were collected from coccygeal vein at different time points around parturition and analyzed for glucose, lactate, non-esterified fatty acids (NEFA), cholesterol, and betahydro-xybutyrate (BHBA). Clinical monitoring of animals was done throughout the experiment at different time points for overall health status, udder edema (UE), manure score, and body condition score (BCS). Results showed that oronasal administration of LPS increased concentrations of glucose and cholesterol in the serum compared to the control group (P < 0.05). The administration of LPS had no effect on concentrations of NEFA, BHBA, and lactate in the serum (P > 0.05). Oronasal LPS did not influence BCS, manure score or the incidence of UE (P > 0.05). Overall, repeated oronasal administration of LPS modulated some serum metabolites related to energy metabolism around parturition in the treated cows. Further research is warranted to elucidate the mechanisms behind greater glucose and cholesterol status in the serum and their potential effects on long-term metabolic health status of dairy cows.

Use of Escherichia coli toxins in sepsis models  [PDF]
Ian Burkovskiy, Juan Zhou, Christian Lehmann
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.43A056

The high prevalence of sepsis in intensive care units and emergency rooms, along with the high lethality of the sepsis cases makes the study of pathophysiology of sepsis critically important. As a preclinical model, endotoxemia is an important tool to study the pathophysiology of sepsis and septic shock. In this review, we discussed aspects of endotoxemia as an experimental model in sepsis research, including different techniques associated with the purification of the endotoxin of Escherichia coli, serotype dependency and dosage dependency of the experimental results.

Shifts in the balance of brain tryptophan metabolism due to age and systemic administration of lipopolysaccharide  [PDF]
Hideki Miura, Tetsuya Shirokawa, Norio Ozaki, Kenichi Isobe
Health (Health) , 2010, DOI: 10.4236/health.2010.23032
Abstract: The kynurenine (KYN) pathway, which is initi-ated by indoleamine 2, 3-dioxygenase (IDO), is a key tryptophan (TRP) metabolic pathway. It shares TRP with the serotonin (5-HT) pathway. Because activation of the KYN pathway by proinflammatory cytokines induces depressive symptoms, shifts in the balance of TRP metabolism to the KYN pathway are closely related to the etiology of depression. In the present study, the influence of age on the effect of the inflammation response system (IRS) on brain TRP metabolism was investigated. Male ICR mice (PND21) were reared for 4 weeks (younger group) or until they reached 1 year of age (older group), and given an intraperitoneal (i.p.) injection of lipopolysaccharide (LPS). The TRP, KYN, and 5-HT levels were measured in the prefrontal cortex, hippocampus, amygdala, and dorsal raphe nuclei. An increase in TRP and 5-HT levels was observed with age in all brain regions, whereas age was associated with decreases in KYN levels in the dorsal raphe nuclei. In all brain regions, LPS increased TRP levels, while it in-creased KYN levels in the prefrontal cortex and amygdala. Reduced KYN/5-HT ratios in all regions were observed with age, whereas increased KYN/5-HT ratios were observed with LPS in all regions except the dorsal raphe nuclei. Thus, age shifted the balance between the KYN and 5-HT pathways toward the 5-HT pathway, and countered the effects of LPS, which shifted the balance to the KYN pathway. These effects are relevant to the etiology of psychiatric disorders in elderly people.
Lipopolysaccharides in Cyanobacteria: A Brief Overview  [PDF]
Sabrina Gemma, Monica Molteni, Carlo Rossetti
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.65038
Abstract: Cyanobacteria are an interesting group of photosynthetic prokaryotes with a great potential in drug discovery and scientific research. Due to their high degree of diversification, they have been able to adapt to almost all ecological niches. Similarly to Gram-negative bacteria, cyanobacterial cell wall contains Lipopolysaccharides (LPSs) in the outer membrane layer. LPSs are molecules that possess the ability to elicit an innate immune response via Toll-like receptor 4 (TLR-4) activation. Cyanobacterial LPSs have been studied to a minor extent compared to Gram-negative bacterial LPSs. However, available data revealed important differences between the LPSs of these two groups of organisms, both in term of structure and biological activity. This review summarizes the current knowledge about cyanobacterial LPSs, highlighting their peculiarity and their potentiality compared to more characterized bacterial LPSs.
The effect of antibacterial agents on the production of nitric oxide induced by lipopolysaccharide in mice  [PDF]
Hampartsoum Barsoumian, Fadi El-Rami, Alexander M. Abdelnoor
Advances in Bioscience and Biotechnology (ABB) , 2010, DOI: 10.4236/abb.2010.12010
Abstract: Some antibacterial agents have been shown to neutralize the biological properties of bacterial lipopolysaccharide (LPS). The aim of this study was to eluci- date the role of gentamicin, tobramycin, imipenem, tigecycline, and isoniazid in affecting the production of nitric oxide (NO) induced by LPS in mice. Groups of mice were injected intraperitoneally with LPS alone, antibacterial agent alone, or LPS in combination with an antibacterial agent. Serum NO levels were determined at 1, 3, 6 and 9 hours post-injection using the Griess reagent method. Thin layer chroma- tography was performed to determine if antibacterial agent—LPS interaction had occurred. All the antibacterial agents suppressed NO production. More- over, LPS-induced production of NO was suppressed by all the antibacterial agents, tobramycin and tigecycline being the most effective at 9 hours post-injection. Blocking of any of the stages leading to NO production by the antibacterial agents is suggested. Moreover, thin layer chromatograms obtained are suggestive of LPS-antibacterial agent interactions.
Effects of prepartal oronasal administration of lipopolysaccharide on milk composition and productivity of transition Holstein dairy cows  [PDF]
Summera Iqbal, Qendrim Zebeli, Dominik A. Mansmann, Suzanna M. Dunn, Burim N. Ametaj
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.33030

The aim of this study was to evaluate the effects of repeated oronasal administration of lipopolysaccharide (LPS) on milk composition and the overall productive performance of dairy cows. One hundred pregnant Holstein dairy cows were randomly assigned to two treatment groups (n = 50). 30 cows out of 100 were selected for intensive sampling (n = 15) starting at 28 d before parturition. Cows were administered orally and nasally with 2 and 1 mL of saline solution, respectively (control), or saline solution containing 3 doses of LPS from Escherichia coli 0111:B4 as follows: 1) 0.01 μg/kg body weight (BW) on d ﹣28, 2) 0.05 μg/kg BW on d ﹣25 and ﹣21, and 3) 0.1 μg/kg BW on d ﹣18 and ﹣14. Daily feed intake and milk production were recorded for each cow during the first 28 d postpartum. Milk samples were obtained once per week and analyzed for various milk components. Overall, results indicated that treatment did not affect feed intake, milk yield, milk efficiency, fat content, fat yield, protein content, protein yield, lactose content, lactose yield, milk urea nitrogen (MUN), total solid contents, fat-corrected milk (FCM), and energy-corrected milk (ECM; P > 0.05). However, milk somatic cell count (SCC) tended to be lower in the treated cows (P < 0.10). Treated primiparous cows showed tendencies for better milk efficiency (P < 0.10), milk-fat content (P = 0.09), and total solid contents (P = 0.06). There was a treatment by week interaction for milk energy (P = 0.03), and tendencies for FCM, ECM, lactose content, and milk efficiency (P < 0.10) with greater values in the treated primiparous animals. Altogether, results of this study showed that oronasal LPS challenges slightly modulated milk composition of periparturient dairy cows.

Inhibition of Lon protease by bacterial lipopolisaccharide (LPS) though inhibition of ATPase  [PDF]
Nahoko Sugiyama, Noriko Minami, Yoshiyuki Ishii, Fumio Amano
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.44077

Lon protease, an ATP-dependent protease in Escherichia coli, degrades abnormal proteins and regulates several important cellular functions. Here we show novel inhibitory effects of lipopolysaccharide (LPS) on Lon protease activities. LPS inhibited the peptidase, protease, and ATPase activities of Lon; and a dose-response study showed that LPS at low doses more effectively inhibited the ATPase activity than the peptidase one, suggesting different susceptibility to LPS of these activities associated with Lon. Structure-activity relationship studies revealed that ReLPS, detoxified LPS, and mono-phosphoryl as well as diphosphoryl lipid A, also showed similar inhibition, suggesting that neither O-antigen polysaccharide nor O-acyl chain, but rather phosphate groups in the lipid A domain, seem to have been responsible for the inhibitory effects. Besides, LPS was co-precipitated with Lon by an anti-Lon antibody, showing the direct binding of LPS to Lon. These results suggest that LPS bound to Lon and inhibited the protease activity of Lon by inhibiting its ATPase activity. These results also seem to be another example of a negatively charged phosphate group in membrane components of Escherichia coli being involved in the regulation of protease activity of Lon through binding to Lon and inhibiting its ATPase activity, as in the case of cardiolipin.

IL-10 Inhibits LPS-Induced Expression of miR-147 in Murine Macrophages  [PDF]
Leah N. Cardwell, Brian K. Weaver
Advances in Biological Chemistry (ABC) , 2014, DOI: 10.4236/abc.2014.44032
Abstract: Interleukin-10 (IL-10) mediates an anti-inflammatory response that constrains immune responses and limits inflammation-associated pathology. IL-10 does so, in part, by selectively inhibiting pro-inflammatory cytokine and chemokine expression induced in macrophages in response to Toll-like receptor (TLR) signaling. The IL-10-mediated anti-inflammatory response is executed through the activation of STAT3 leading to induction of target genes referred to as IL-10-induced genes. As miRNAs have emerged as important negative regulators of gene expression in various systems, we sought to address whether the IL-10-mediated anti-inflammatory response acts through regulated expression of miRNA genes. Using quantitative PCR-based arrays, we examined 140 miRNA genes with putative roles in inflammation for changes in expression in response to IL-10 and lipopoly-saccharide (LPS) in primary mouse macrophages. IL-10 stimulation resulted in the inhibition of miR-147 expression induced in response to LPS, while having a potentiating effect on the induction of miR-455. miR-147 is the second TLR-induced miRNA, in addition to miR-155, identified to be counter-regulated by IL-10. Its suppression by IL-10 suggests that miR-147 may have an unknown pro-inflammatory function in TLR-triggered macrophages. The results extend the notion that IL-10 selectively regulates expression of miRNA genes, and that miRNA-mediated pathways are a component of the IL-10-mediated anti-inflammatory response.
Region Specific Effects of Maternal Immune Activation on Offspring Neuroimmune Function  [PDF]
Heping Zhou
Open Journal of Immunology (OJI) , 2015, DOI: 10.4236/oji.2015.52006
Abstract: Growing evidence suggests that maternal immune activation has a significant impact on the immuno-competence of the offspring. The present study aimed to characterize region-specific effects of maternal immune activation on the offspring’s neuroimmune function. The offspring born to dams treated with saline or lipopolysaccharide (LPS) at gestational day 18 was stimulated with saline or LPS at postnatal day 21, and the mRNA expression of various inflammatory genes in different brain regions of the offspring was analyzed. The offspring born to saline-treated dams exhibited a typical neuroimmune response with elevated levels of cytokines and chemokines following LPS stimulation in all four brain regions examined. In contrast, the offspring born to LPS- treated dams exhibited significantly reduced mRNA induction of cytokines and chemokines following LPS stimulation in the prefrontal cortex but not in the brainstem when compared with pups born to saline-treated dams. Furthermore, the mRNA expression of LPS-induced I-κBζ was significantly attenuated in the prefrontal cortex when compared with pups born to saline-treated dams. These results suggest that maternal LPS may have differential effects on the neuroimmune function in different regions of the offspring brain, and highlight the importance of maternal milieu in the development of neuroimmune function in the offspring.
The Interaction of Heat and Lipopolysaccharide on the Expression Levels of Receptor Activator of NF-κB Ligand and Osteoprotegerin in Human Periodontal Ligament Cells  [PDF]
Lan Zhang, Qinghua Zheng, Xuedong Zhou, Lu Tang, Qian Wang, Xiaoyu Li, Dingming Huang
Open Journal of Stomatology (OJST) , 2015, DOI: 10.4236/ojst.2015.510030
Abstract: Aim: To investigate the expression levels of receptor activator of NF-κB ligand (RANKL) and oste-oprotegerin (OPG) in human periodontal ligament fibroblasts when stimulated with heat in infective conditions. Methods: Periodontal ligament fibroblasts were subjected to various temperature increases for 5 min with or without 10 ng/mL lipopolysaccharide (LPS) and then maintained at 37℃ for 6 h. After that, the expression levels of RANKL and OPG were investigated using real-time RT-PCR and ELISA. As a positive or negative control, the cells were cultured at 37℃ with or without 10 ng/mL LPS. Data were analyzed using one-way ANOVA at a significant level of p = 0.05. Results: The mRNA expression levels of RANKL and OPG were both down-regulated when the cells were heated in infective conditions. The release of sRANKL was increased at low temperatures in such infection; while at high temperatures heat treatment down-regulated the release of sRANKL induced by LPS. The relative RANKL/OPG expression ratios were increased at low temperatures in infective conditions. Conclusions: The interactions between heat and LPS would affect the balance between RANKL and OPG in periodontal ligament fibroblasts when they were heated in infective conditions. Such infection may be the reason why bone resorption occurs in the local area after warm vertical compaction.
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