Propofol reduces lipopolysaccharide-induced, NADPH oxidase (NOX 2) mediated TNF- α and IL-6 production in macrophages

Porphyromonas gingivalis triggers microglia activation and neurodegenerative processes through NOX4

Periodontitis and infections with periodontal bacteria have been highlighted as risk factors for dementia. In recent years, attention has been drawn to the role of microglia cells in neurodegenerative diseases. However, there is limited knowledge of the influence of periodontal bacteria on microglia cells. The aim of the present study was to investigate the interactions between the periodontal bacteria Porphyromonas gingivalis and microglia cells and to unravel whether these interactions could contribute to the pathology of Alzheimer's disease. We found, through microarray analysis, that stimulation of microglia cells with P. gingivalis resulted in the upregulation of several Alzheimer's disease-associated genes, including NOX4. We also showed that P. gingivalis lipopolysaccharides (LPS) mediated reactive oxygen species (ROS) production and interleukin 6 (IL-6) and interleukin 8 (IL-8) induction via NOX4 in microglia. The viability of neurons was shown to be reduced by conditioned media from microglia cells stimulated with P. gingivalis LPS and the reduction was NOX4 dependent. The levels of total and phosphorylated tau in neurons were increased by conditioned media from microglia cells stimulated with P. gingivalis or LPS. This increase was NOX4-dependent. In summary, our findings provide us with a potential mechanistic explanation of how the periodontal pathogen P. gingivalis could trigger or exacerbate AD pathogenesis.

Low-grade endotoxemia and risk of recurrent thrombosis in primary antiphospholipid syndrome. The multicenter ATHERO-APS study

INTRODUCTION

Low-grade endotoxemia is associated with systemic inflammation, enhanced oxidative stress and cardiovascular events in different clinical settings, but its possible role as "second hit" in patients with primary antiphospholipid syndrome (PAPS) has never been investigated.

PURPOSE

To evaluate the relationship between plasma lipopolysaccharide (LPS) levels, oxidative stress markers and risk of thrombosis in the prospective multicenter ATHERO-APS study.

METHODS

Baseline LPS, soluble NADPH-oxidase 2-derived peptide (sNOX-dp), H2O2 production, hydrogen peroxide breakdown activity (HBA), and nitric oxide (NO) bioavailability were compared in 97 PAPS, 16 non-thrombotic aPL carriers and 21 controls (CTRL) matched for age and sex. Correlations among laboratory variables were explored by Rho Spearman's correlation (rS). Cox-regression analysis was performed to assess the association between LPS and risk for a composite outcome of cardiovascular death, venous and arterial thromboembolism.

RESULTS

In the whole cohort (median age 51 years (IQR 43-60), 72 % female), PAPS demonstrated higher levels of LPS, sNOX-dp and H2O2 and lower levels of NO and HBA compared to non-thrombotic aPL carriers and CTRL. LPS levels were inversely correlated with HBA (rS: -0.295, p = 0.001) and NO (rS: -0.322, p < 0.001) and directly correlated with sNOX-dp (rS:0.469, p < 0.001) and H202 (rS:0.282, p < 0.001). PAPS showed higher levels of LPS, sNOX-dp and H2O2 and lower levels of NO and HBA compared to aPL carriers and CTRL. After a 4.7 years follow-up of, 11 composite outcomes were reported in PAPS (2.5 per 100 patient-years) while none was observed in aPL carriers. On Cox-regression analysis, patients with LPS above the median (>23.1 pg/ml) had a 5-fold increased risk of composite outcome compared to those with LPS below the median, after adjustment for sex, age, diabetes, and global antiphospholipid syndrome score.

CONCLUSION

Low-grade endotoxemia is associated with an increased oxidative stress and a higher risk of thrombosis in PAPS. Its prognostic value in carriers needs to be investigated in larger cohorts.

Thioredoxin/Glutaredoxin Systems and Gut Microbiota in NAFLD: Interplay, Mechanism, and Therapeutical Potential

Non-alcoholic fatty liver disease (NAFLD) is a common clinical disease, and its pathogenesis is closely linked to oxidative stress and gut microbiota dysbiosis. Recently accumulating evidence indicates that the thioredoxin and glutaredoxin systems, the two thiol-redox dependent antioxidant systems, are the key players in the NAFLD's development and progression. However, the effects of gut microbiota dysbiosis on the liver thiol-redox systems are not well clarified. This review explores the role and mechanisms of oxidative stress induced by bacteria in NAFLD while emphasizing the crucial interplay between gut microbiota dysbiosis and Trx mediated-redox regulation. The paper explores how dysbiosis affects the production of specific gut microbiota metabolites, such as trimethylamine N-oxide (TMAO), lipopolysaccharides (LPS), short-chain fatty acids (SCFAs), amino acids, bile acid, and alcohol. These metabolites, in turn, significantly impact liver inflammation, lipid metabolism, insulin resistance, and cellular damage through thiol-dependent redox signaling. It suggests that comprehensive approaches targeting both gut microbiota dysbiosis and the thiol-redox antioxidant system are essential for effectively preventing and treating NAFLD. Overall, comprehending the intricate relationship between gut microbiota dysbiosis and thiol-redox systems in NAFLD holds significant promise in enhancing patient outcomes and fostering the development of innovative therapeutic interventions.

Macrophage Polarization and Reprogramming in Acute Inflammation: A Redox Perspective

Macrophage polarization refers to the process by which macrophages can produce two distinct functional phenotypes: M1 or M2. The balance between both strongly affects the progression of inflammatory disorders. Here, we review how redox signals regulate macrophage polarization and reprogramming during acute inflammation. In M1, macrophages augment NADPH oxidase isoform 2 (NOX2), inducible nitric oxide synthase (iNOS), synaptotagmin-binding cytoplasmic RNA interacting protein (SYNCRIP), and tumor necrosis factor receptor-associated factor 6 increase oxygen and nitrogen reactive species, which triggers inflammatory response, phagocytosis, and cytotoxicity. In M2, macrophages down-regulate NOX2, iNOS, SYNCRIP, and/or up-regulate arginase and superoxide dismutase type 1, counteract oxidative and nitrosative stress, and favor anti-inflammatory and tissue repair responses. M1 and M2 macrophages exhibit different metabolic profiles, which are tightly regulated by redox mechanisms. Oxidative and nitrosative stress sustain the M1 phenotype by activating glycolysis and lipid biosynthesis, but by inhibiting tricarboxylic acid cycle and oxidative phosphorylation. This metabolic profile is reversed in M2 macrophages because of changes in the redox state. Therefore, new therapies based on redox mechanisms have emerged to treat acute inflammation with positive results, which highlights the relevance of redox signaling as a master regulator of macrophage reprogramming.

Effects of propofol and its formulation components on macrophages and neutrophils in obese and lean animals

We hypothesized whether propofol or active propofol component (2,6-diisopropylphenol [DIPPH] and lipid excipient [LIP-EXC]) separately may alter inflammatory mediators expressed by macrophages and neutrophils in lean and obese rats. Male Wistar rats (n = 10) were randomly assigned to receive a standard (lean) or obesity-inducing diet (obese) for 12 weeks. Animals were euthanized, and alveolar macrophages and neutrophils from lean and obese animals were exposed to propofol (50 µM), active propofol component (50 µM, 2,6-DIPPH), and lipid excipient (soybean oil, purified egg phospholipid, and glycerol) for 1 h. The primary outcome was IL-6 expression after propofol and its components exposure by alveolar macrophages extracted from bronchoalveolar lavage fluid. The secondary outcomes were the production of mediators released by macrophages from adipose tissue, and neutrophils from lung and adipose tissues, and neutrophil migration. IL-6 increased after the exposure to both propofol (median [interquartile range] 4.14[1.95-5.20]; p = .04) and its active component (2,6-DIPPH) (4.09[1.67-5.91]; p = .04) in alveolar macrophages from obese animals. However, only 2,6-DIPPH increased IL-10 expression (7.59[6.28-12.95]; p = .001) in adipose tissue-derived macrophages. Additionally, 2,6-DIPPH increased C-X-C chemokine receptor 2 and 4 (CXCR2 and CXCR4, respectively) in lung (10.08[8.23-29.01]; p = .02; 1.55[1.49-3.43]; p = .02) and adipose tissues (8.78[4.15-11.57]; p = .03; 2.86[2.17-3.71]; p = .01), as well as improved lung-derived neutrophil migration (28.00[-3.42 to 45.07]; p = .001). In obesity, the active component of propofol affected both the M1 and M2 markers as well as neutrophils in both alveolar and adipose tissue cells, suggesting that lipid excipient may hinder the effects of active propofol.

Propofol improves brain injury induced by chronic cerebral hypoperfusion in rats

To study effect of propofol on cognitive dysfunction and brain injury in a rat model of chronic cerebral hypoperfusion. The bilateral carotid artery ligation (bilateral common carotid artery occlusion and BCCAO) to establish rat model of chronic cerebral hypoperfusion and randomly assigned to 4 groups (n = 10): sham-operation group treated with saline model group, propofol treatment model group, normal saline treatment, propofol treatment in the sham-operation group; continuous intraperitoneal injection of propofol and saline for 12 weeks. Morris water maze was used to evaluate the learning and memory ability of rats. Determination of central cholinergic and oxidative stress in brain tissue by spectrophotometry. Detection of inflammatory response in brain tissue by immunohistochemistry and ELISA method. Detection of neuronal loss in brain tissue by Nissl and TUNEL staining. Compared with the saline-treated model group, propofol in model group significantly increased the rat brain tissue SOD activity (p < .01) and GPX activity (p < .01), decreased the MDA levels (p < .01) and protein carbonyl compound levels (p < .01). The propofol treatment of model group rats hippocampal GFAP-immunoreactive satellite glial cells (p < .01) and immune Iba1-positive microglia cells (p < .01) area percent compared to saline-treated model group decreased significantly. The number of normal propofol treatment of model group rats hippocampus neuron than in physiological saline treatment model group rats was significantly increased (p < .01). Propofol can improve chronic cerebral hypoperfusion in rats induced by cognitive dysfunction and brain damage.

UPLC-ESI-Q-TOF-MS-Based Metabolite Profiling, Antioxidant and Anti-Inflammatory Properties of Different Organ Extracts of Abeliophyllum distichum

Plant extracts have gained more attention as natural therapeutic agents against inflammation characterized by an overproduction of several inflammatory mediators such as reactive oxygen species and pro-inflammatory cytokines. Although Abeliophyllum distichum Nakai is generally known for its ornamental value, recent pharmacological research has demonstrated its potential therapeutic properties. Thus, to further evaluate the applicability of A. distichum in the food, cosmetic, and medical industries, we identified the phytochemicals in three organ extracts (fruits: AF, branches: AB, leaves: AL) of A. distichum and determined their antioxidant and anti-inflammatory activities. Using UPLC-ESI-Q-TOF-MS, a total of 19 compounds, including dendromoniliside D, forsythoside B, isoacteoside, isomucronulatol 7-O-Glucoside, plantamajoside, and wighteone were identified in the A. distichum organ extracts. AB exhibited a strong reducing power, an oxygen radical antioxidant capacity, and radical scavenging values compared with other samples, whereas AL exhibited the best anti-inflammatory properties. Gene expression, western blot, and molecular docking analyses suggested that the anti-inflammatory effect of AL was mediated by its ability to suppress lipopolysaccharide (LPS)-induced production of reactive oxygen species and/or inhibit LPS-stimulated activation of extracellular signal-regulated protein kinases (ERK1/2) in RAW264.7 cells. Collectively, these results indicate that AL is a potential source of phytochemicals that could be used to treat inflammation-associated diseases.

[Molecular mechanism underlying the inhibitory effect of propofol on lipopolysaccharide-induced pyroptosis of mouse bone marrow-derived macrophages]

OBJECTIVE

To investigate the molecular mechanism underlying the inhibitory effect of propofol on pyroptosis of macrophages.

METHODS

Macrophages derived from bone marrow were extracted and divided into three groups: control group, LPS+ATP group and propofol+LPS+ATP group. The control group was not given any treatment; LPS+ATP group was given LPS 1 μg/mL stimulation for 4 h, then ATP 4 mM stimulation for 1 h; Propofol+LPS+ATP group was given propofol+LPS 1 μg/mL stimulation for 4 h, then ATP stimulation for 1 h. After treatment, the supernatant and cells of cell culture were collected. the cell activity was detected by CCK8 and flow cytometry. The inflammatory cytokines IL-1βand IL-18 were detected by Elisa. Western blot was used to detect the expression of caspase-1 protein and TLR4 on cell membran Immunohistochemical fluorescence was used to detect apoptosis of cells.

RESULTS

LPS+ATP significantly decreased the viability of the macrophages and increased the cellular production of IL-1β and IL-18, activation of caspase-1 protein and the expression of TLR-4 on the cell membrane (P &lt; 0.05). Treatment with propofol obviously reversed the changes induced by LPS+ATP.

CONCLUSIONS

LPS+ATP can induce pyroptosis of mouse bone marrow-derived macrophages, and propofol effectively inhibits such cell death, suggesting that propofol anesthesia is beneficial during operation and helps to regulate the immune function of in patients with sepsis.

MsrA Suppresses Inflammatory Activation of Microglia and Oxidative Stress to Prevent Demyelination via Inhibition of the NOX2-MAPKs/NF-κB Signaling Pathway

Introduction

Demyelination causes neurological deficits involving visual, motor, sensory symptoms. Deregulation of several enzymes has been identified in demyelination, which holds potential for the development of treatment strategies for demyelination. However, the specific effect of methionine sulfoxide reductase A (MsrA) on demyelination remains unclear. Hence, this study aims to explore the effect of MsrA on oxidative stress and inflammatory response of microglia in demyelination.

Methods

Initially, we established a mouse model with demyelination induced by cuprizone and a cell model provoked by lipopolysaccharide (LPS). The expression of MsrA in wild-type (WT) and MsrA-knockout (MsrA^-/-) mice were determined by RT-qPCR and Western blot analysis. In order to further explore the function of MsrA on inflammatory response, and oxidative stress in demyelination, we detected the expression of microglia marker Iba1, inflammatory factors TNF-α and IL-1β and intracellular reactive oxygen species (ROS), superoxide dismutase (SOD) activity, as well as expression of the NOX2-MAPKs/NF-κB signaling pathway-related genes in MsrA^-/- mice and LPS-induced microglia following different treatments.

Results

MsrA expression was downregulated in MsrA^-/- mice. MsrA silencing was shown to produce severely injured motor coordination, increased expressions of Iba1, TNF-α, IL-1β, ROS and NOX2, and extent of ERK, p38, IκBα, and p65 phosphorylation, but reduced SOD activity. Conjointly, our study suggests that Tat-MsrA fusion protein can prevent the cellular inflammatory response and subsequent demyelination through negative regulation of the NOX2-MAPKs/NF-κB signaling pathway.

Conclusion

Our data provide a profound insight on the role of endogenous antioxidative defense systems such as MsrA in controlling microglial function.

Apocynin Dietary Supplementation Delays Mouse Ovarian Ageing

Advanced maternal age is associated with higher infertility rates, pregnancy-associated complications, and progeny health issues. The ovary is considered the main responsible for these consequences due to a continuous decay in follicle number and oocyte quality. Intracellular imbalance between oxidant molecules and antioxidant mechanisms, in favour of the former, results in oxidative stress (OS) that is believed to contribute to ovarian ageing. This work is aimed at evaluating whether an age-related increase in ovarian OS, inflammation, and fibrosis may contribute to tissue dysfunction and whether specific antioxidant supplementation with a NADPH oxidase inhibitor (apocynin) could ameliorate them. Mice aged 8–12 weeks (reproductively young) or 38-42 weeks (reproductively aged) were employed. Aged mice were divided into two groups, with one receiving apocynin (5 mM) in the drinking water, for 7 weeks, upon which animals were sacrificed and their ovaries collected. Ovarian structure was similar at both ages, but the ovaries from reproductively aged mice exhibited lipofuscin deposition, enhanced fibrosis, and a significant age-related reduction in primordial and primary follicle number when compared to younger animals. Protein carbonylation and nitration, and markers of OS were significantly increased with age. Moreover, mRNA levels of inflammation markers, collagens, metalloproteinases (MMPs), and tissue inhibitor MMPs (TIMPs) were upregulated. Expression of the antifibrotic miRNA29c-3p was significantly reduced. Apocynin supplementation ameliorated most of the age-related observed changes, sometimes to values similar to those observed in young females. These findings indicate that there is an age-related increase in OS that plays an important role in enhancing inflammation and collagen deposition, contributing to a decline in female fertility. Apocynin supplementation suggests that the imbalance can be ameliorated and thus delay ovarian ageing harmful effects.

Effect of Propofol on the Production of Inflammatory Cytokines by Human Polarized Macrophages

Macrophages are key immune system cells involved in inflammatory processes. Classically activated (M1) macrophages are characterized by strong antimicrobicidal properties, whereas alternatively activated (M2) macrophages are involved in wound healing. Severe inflammation can induce postoperative complications during the perioperative period. Invasive surgical procedures induce polarization to M1 macrophages and associated complications. As perioperative management, it is an important strategy to regulate polarization and functions of macrophages during inflammatory processes. Although propofol has been found to exhibit anti-inflammatory activities in monocytes and macrophages, it is unclear whether propofol regulates the functions of M1 and M2 macrophages during inflammatory processes. This study therefore investigated the effects of propofol on human macrophage polarization. During M1 polarization, propofol suppressed the production of IL-6 and IL-1β but did not affect TNF-α production. In contrast, propofol did not affect the gene expression of M2 markers, such as IL-10, TGF-β, and CD206, during M2 polarization. Propofol was similar to the GABA_A agonist muscimol in inducing nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and inhibiting IL-6 and IL-1β, but not TNF-α, production. Knockdown of Nrf2 using siRNA significantly reduced the effect of propofol on IL-6 and IL-1β production. These results suggest that propofol prevents inflammatory responses during polarization of human M1 macrophages by suppressing the expression of IL-6 and IL-1β through the GABA_A receptor and the Nrf2-mediated signal transduction pathway.

The role of macrophages in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and its inflammatory and often progressive subtype nonalcoholic steatohepatitis (NASH) are becoming the leading cause of liver-related morbidity and mortality worldwide, and a primary indication for liver transplantation. The pathophysiology of NASH is multifactorial and not yet completely understood; however, innate immunity is a major contributing factor in which liver-resident macrophages (Kupffer cells) and recruited macrophages play a central part in disease progression. In this Review, we assess the evidence for macrophage involvement in the development of steatosis, inflammation and fibrosis in NASH. In this process, not only the polarization of liver macrophages towards a pro-inflammatory phenotype is important, but adipose tissue macrophages, especially in the visceral compartment, also contribute to disease severity and insulin resistance. Macrophage activation is mediated by factors such as endotoxins and translocated bacteria owing to increased intestinal permeability, factors released from damaged or lipoapoptotic hepatocytes, as well as alterations in gut microbiota and defined nutritional components, including certain free fatty acids, cholesterol and their metabolites. Reflecting the important role of macrophages in NASH, we also review studies investigating drugs that target macrophage recruitment to the liver, macrophage polarization and their inflammatory effects as potential treatment options for patients with NASH.

Endothelial-cell inflammation and damage by reactive oxygen species are prevented by propofol via ABCA1-mediated cholesterol efflux

Background: Cholesterol efflux efficiency, reactive oxygen species, and inflammation are closely related to cardiovascular diseases. Our aim was to investigate the effect of propofol on cholesterol-loaded rat aortic endothelial cells after high-density lipoprotein treatment in vitro. Methods and Results: The results showed that propofol promoted cholesterol efflux and ameliorated inflammation and reactive oxygen species overproduction according to the analysis of p65 nuclear translocation and a 2',7'-dichlorofluorescin diacetate assay, respectively. Conclusions: These results provide a possible explanation for the anti-inflammatory, antioxidant, and cholesterol efflux-promoting effects of propofol on rat aortic endothelial cells after incubation with high-density lipoprotein.

Pro-inflammatory hepatic macrophages generate ROS through NADPH oxidase 2 via endocytosis of monomeric TLR4-MD2 complex

Reactive oxygen species (ROS) contribute to the development of non-alcoholic fatty liver disease. ROS generation by infiltrating macrophages involves multiple mechanisms, including Toll-like receptor 4 (TLR4)-mediated NADPH oxidase (NOX) activation. Here, we show that palmitate-stimulated CD11b⁺F4/80^low hepatic infiltrating macrophages, but not CD11b⁺F4/80^high Kupffer cells, generate ROS via dynamin-mediated endocytosis of TLR4 and NOX2, independently from MyD88 and TRIF. We demonstrate that differently from LPS-mediated dimerization of the TLR4–MD2 complex, palmitate binds a monomeric TLR4–MD2 complex that triggers endocytosis, ROS generation and increases pro-interleukin-1β expression in macrophages. Palmitate-induced ROS generation in human CD68^lowCD14^high macrophages is strongly suppressed by inhibition of dynamin. Furthermore, Nox2-deficient mice are protected against high-fat diet-induced hepatic steatosis and insulin resistance. Therefore, endocytosis of TLR4 and NOX2 into macrophages might be a novel therapeutic target for non-alcoholic fatty liver disease.

Reactive species of oxygen promote the development of hepatic steatosis. Here, Kim et al. demonstrate that palmitate stimulates macrophage infiltration and increases oxidative stress during steatosis by binding to the TLR4–MD2 complex, which results in the activation of NOX2.

A GalNAc/Gal-specific lectin from the sea mussel Crenomytilus grayanus modulates immune response in macrophages and in mice

A GalNAc/Gal-specific lectin (CGL) from the edible mussel Crenomytilus grayanus has been demonstrated to exhibit antibacterial properties. However, the mechanism of immune modulation by CGL in mammalian cells remains unclear. Here, we demonstrated that CGL can activate immune responses in macrophages and in mice. In the in vitro cell models, CGL induced tumour necrosis factor-α and interleukin-6 secretion in mouse RAW264.7 macrophages, mouse bone marrow-derived macrophages, human THP-1 macrophages, human peripheral blood mononuclear cells and human blood monocyte-derived macrophages. The CGL-mediated cytokine production was regulated by reactive oxygen species, mitogen-activated protein kinases, protein kinase C-α/δ and NF-κB. Interestingly, in lipopolysaccharide-activated macrophages, CGL induced endotoxin tolerance (characterized by the downregulation of nitric oxide, inducible nitric oxide synthase, interleukin-6 and cyclooxygenase II) via the downregulation of IRAK2 expression, JNK1/2 phosphorylation and NF-κB activation. CGL also slightly increased the bactericidal activity of macrophages and induced cytokine production in mouse models. Overall, our data indicate that CGL has the potential to be used as an immune modulator in mammals.

Heat-Processed Scutellariae Radix Enhances Anti-Inflammatory Effect against Lipopolysaccharide-Induced Acute Lung Injury in Mice via NF- κ B Signaling

The present study was conducted to examine whether heat-processed Scutellariae Radix has an ameliorative effect on lipopolysaccharide- (LPS-) induced acute lung injury in mice. The effects of Scutellariae Radix heat-processed at 160°C (HSR) were compared with those of nonheat-processed Scutellariae Radix (NSR). The LPS-treated group displayed a markedly decreased body weight and significantly increased lung weight; however, the administration of NSR or HSR improved both the body and lung weights. The increased oxidative stress and inflammatory biomarker levels in the serum and lung were reduced significantly with HSR. The reduced superoxide dismutase and catalase increased significantly by both NSR and HSR. Also, the dysregulated oxidative stress and inflammation were significantly ameliorated by NSR and HSR. The expression of inflammatory mediators and cytokines by nuclear factor-kappa B activation was modulated through inhibition of a nuclear factor kappa Bα degradation. Also, lung histological change was markedly suppressed by HSR rather than NSR. Overall, the ameliorative effects of HSR were superior to those when being nonheat-processed. The representative flavonoid contents of Scutellariae Radix that include baicalin, baicalein, and wogonin were greater by heat process. These data reveal heat-processed Scutellariae Radix may be a critical factor involved in the improvement of lung disorders caused by LPS.

Nox family NADPH oxidases: Molecular mechanisms of activation

NADPH oxidases of the Nox family are important enzymatic sources of reactive oxygen species (ROS). Numerous homologue-specific mechanisms control the activity of this enzyme family involving calcium, free fatty acids, protein-protein interactions, intracellular trafficking, and posttranslational modifications such as phosphorylation, acetylation, or sumoylation. After a brief review on the classic pathways of Nox activation, this article will focus on novel mechanisms of homologue-specific activity control and on cell-specific aspects which govern Nox activity. From these findings of the recent years it must be concluded that the activity control of Nox enzymes is much more complex than anticipated. Moreover, depending on the cellular activity state, Nox enzymes are selectively activated or inactivated. The complex upstream signaling aspects of these events make the development of "intelligent" Nox inhibitors plausible, which selectively attenuate disease-related Nox-mediated ROS formation without altering physiological signaling ROS. This approach might be of relevance for Nox-mediated tissue injury in ischemia-reperfusion and inflammation and also for chronic Nox overactivation as present in cancer initiation and cardiovascular disease.

Propofol attenuates LPS-induced tumor necrosis factor-α, interleukin-6 and nitric oxide expression in canine peripheral blood mononuclear cells possibly through down-regulation of nuclear factor (NF)-κB activation

Sepsis is a major cause of mortality in intensive care medicine. Propofol, an intravenous general anesthetic, has been suggested to have anti-inflammatory properties and able to prevent sepsis induced by Gram-positive and Gram-negative bacteria by down-regulating the gene expression of pro-inflammatory cytokines. However, propofol’s anti-inflammatory effects upon canine peripheral blood mononuclear cells (PBMCs) have not yet been clarified. Here, we isolate canine PBMCs and investigate the effects of propofol on the gene expressions of both lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α and upon the production of nitric oxide (NO). Through real-time quantitative PCR and the Griess reagent system, we found that non-cytotoxic levels of propofol significantly inhibited the release of NO and IL-6 and TNF-α gene expression in LPS-induced canine PBMCs. Western blotting revealed that LPS does significantly increase the expression of inducible NO synthase (iNOS) protein in canine PBMCs, while pretreatment with propofol significantly decreases the LPS-induced iNOS protein expression. Propofol, at concentration of 25 µM and 50 µM, also significantly inhibited the LPS-induced nuclear translocation of nuclear factor (NF)-κB p65 protein in canine PBMCs. This diminished TNF-α, IL-6 and iNOS expression, and NO production was in parallel to the respective decreased NF-κB p65 protein nuclear translocation in the LPS-activated canine PBMCs pretreated with 25 µM and 50 µM propofol. This suggests that non-cytotoxic levels of propofol pretreatment can down-regulate LPS-induced inflammatory responses in canine PBMCs, possibly by inhibiting the nuclear translocation of the NF-κB p65 protein.