Protective Effect of Electroacupuncture on the Barrier Function of Intestinal Injury in Endotoxemia through HO-1/PINK1 Pathway-Mediated Mitochondrial Dynamics Regulation.

Background and Aims: Endotoxemia (ET) is a common critical illness in patients receiving intensive care and is associated with high mortality and prolonged hospital stay. The intestinal epithelial cell dysfunction is regarded as the "engine" of deteriorated ET. Although electroacupuncture (EA) can mitigate endotoxin-induced intestinal epithelial cell dysfunction in ET, the mechanism through which EA improves endotoxin-induced intestinal injury for preventing ET deterioration needs further investigation. Methods: An in vivo ET model was developed by injecting lipopolysaccharide (LPS) in wild-type and PINK1-knockout mice. An in vitro model was also established by incubating epithelial cells in the serum samples obtained from both groups of mice. Hemin and zinc protoporphyrin IX (ZnPP) were applied to activate or inhibit heme oxygenase 1 (HO-1) production. EA treatment was performed for 30 min consecutively for 5 days before LPS injection, and on the day of the experiment, EA was performed throughout the process. Samples were harvested at 6 h after LPS induction for analyzing tissue injury, oxidative stress, ATP production, activity of diamine oxidase (DAO), and changes in the levels of HO-1, PTEN-induced putative kinase 1 (PINK1), mitochondrial fusion and fission marker gene, caspase-1, and interleukin 1 beta (IL-1ß). Results: In the wild-type models (both in vivo and vitro), EA alleviated LPS-induced intestinal injury and mitochondrial dysfunction, as indicated by decreased reactive oxygen species (ROS) production and oxygen consumption rate (OCR) and reduced levels of mitochondrial fission proteins. EA treatment also boosted histopathological morphology, ATP levels, DAO activity, and levels of mitochondrial fusion proteins in vivo and vitro. The effect of EA was enhanced by hemin but suppressed by Znpp. However, EA + AP, Znpp, or hemin had no effects on the LPS-induced, PINK1-knocked out mouse models. Conclusion: EA may improve the HO-1/PINK1 pathway-mediated mitochondrial dynamic balance to protect the intestinal barrier in patients with ET.

Application of Bone Marrow Mesenchymal Stem Cells Effectively Eliminates Endotoxemia to Protect Rat from Acute Liver Failure Induced by Thioacetamide.

BACKGROUND: Endotoxemia is related to worse clinical outcomes in acute liver failure (ALF), but its management remains unsatisfactory. In this study, we aimed to assess whether the application of bone marrow mesenchymal stem cells (BMSCs) could eliminate endotoxemia and protect rats against ALF induced by thioacetamide (TAA). METHODS: BMSCs were isolated from rats and identified by the specific morphology, differentiation potential, and surface markers. The optimal dose of TAA for this study was explored and TAA-induced ALF rats were randomized to three groups: the normal control group (Saline), ALF group (TAA + Saline), and BMSCs-treated group (TAA + BMSCs). The intestinal migration and differentiation of BMSCs was tracked in vivo, and intestinal permeability, endotoxin and inflammatory cytokines, histology, and mortality were analyzed. Moreover, we added the inhibitor of the PI3K/AKT/mTOR signaling pathway into the co-culture system of BMSCs with enterocytes and then performed CK and Villin expression experiments to assess the role of PI3K/AKT/mTOR signal pathway in the intestinal differentiation of BMSCs. RESULTS: BMSCs migrated to the intestinal injury sites and differentiated into enterocytes, intestinal permeability was decreased compared with the ALF group. The higher expression of endotoxin and inflammatory cytokines were reversed after BMSCs transplantation in rats with ALF. Mortality and intestinal lesion were significantly decreased. Blocking the PI3K/AKT/mTOR signal pathway inhibited BMSCs' intestinal differentiation in vitro. CONCLUSION: BMSCs can eliminate endotoxemia and reduce mortality in rats with ALF, and the PI3K/AKT/mTOR signal pathway is involved in intestinal differentiation. BMSCs transplantation could be a potential candidate for the treatment of endotoxemia in ALF.

Splenic Nerve Neuromodulation Reduces Inflammation and Promotes Resolution in Chronically Implanted Pigs.

Neuromodulation of the immune system has been proposed as a novel therapeutic strategy for the treatment of inflammatory conditions. We recently demonstrated that stimulation of near-organ autonomic nerves to the spleen can be harnessed to modulate the inflammatory response in an anesthetized pig model. The development of neuromodulation therapy for the clinic requires chronic efficacy and safety testing in a large animal model. This manuscript describes the effects of longitudinal conscious splenic nerve neuromodulation in chronically-implanted pigs. Firstly, clinically-relevant stimulation parameters were refined to efficiently activate the splenic nerve while reducing changes in cardiovascular parameters. Subsequently, pigs were implanted with a circumferential cuff electrode around the splenic neurovascular bundle connected to an implantable pulse generator, using a minimally-invasive laparoscopic procedure. Tolerability of stimulation was demonstrated in freely-behaving pigs using the refined stimulation parameters. Longitudinal stimulation significantly reduced circulating tumor necrosis factor alpha levels induced by systemic endotoxemia. This effect was accompanied by reduced peripheral monocytopenia as well as a lower systemic accumulation of CD16+CD14high pro-inflammatory monocytes. Further, lipid mediator profiling analysis demonstrated an increased concentration of specialized pro-resolving mediators in peripheral plasma of stimulated animals, with a concomitant reduction of pro-inflammatory eicosanoids including prostaglandins. Terminal electrophysiological and physiological measurements and histopathological assessment demonstrated integrity of the splenic nerves up to 70 days post implantation. These chronic translational experiments demonstrate that daily splenic nerve neuromodulation, via implanted electronics and clinically-relevant stimulation parameters, is well tolerated and is able to prime the immune system toward a less inflammatory, pro-resolving phenotype.

Therapeutic Rationale for Endotoxin Removal with Polymyxin B Immobilized Fiber Column (PMX) for Septic Shock.

Endotoxin removal therapy with polymyxin B immobilized fiber column (PMX) has been clinically applied for sepsis and septic shock patients since 1994. The effectiveness and usefulness of this therapy have been demonstrated for more than a quarter of a century. However, a documented survival benefit has not yet been demonstrable in a large, multicenter, randomized and controlled trial. Following the findings derived from a large sepsis clinical trial with PMX in North America, a new trial is ongoing to determine if PMX has a long-term survival benefit when administered to septic patients. Another approach to support a survival benefit from intervention with PMX is to utilize a detailed analysis available from a large clinical data base. The endotoxin adsorption capacity of PMX columns in vitro and the effectiveness of PMX columns can be further demonstrable in animal models. The capability of PMX and details of its mechanism of action to intervene in the sepsis cascade and impede organ dysfunction in septic patients is not fully understood. The surface antigen expression in monocytes and neutrophils are improved after PMX therapy. Immunomodulatory effects as a result of endotoxin removal and/or other mechanisms of action have been suggested. These effects and other potential immune effects may explain some of the improved effects upon organ dysfunction of sepsis and septic shock patients. Endotoxemia may be involved in the pathophysiology of other diseases than sepsis. A rapid diagnostic method to detect and target endotoxemia could allow us to practice precision medicine and expand the clinical indications of endotoxin removal therapy.

Effect of supportive therapy on the pharmacokinetics of intravenous marbofloxacin in endotoxemic sheep.

The purpose of this study was to determine the influences of supportive therapy (ST) on the pharmacokinetics (PK) of marbofloxacin in lipopolysaccharide (LPS)-induced endotoxemic sheep. Furthermore, minimum inhibitory concentration (MIC) of marbofloxacin against Escherichia coli, Mannheimia haemolytica, Pasteurella multocida, Klebsiella pneumoniae, Salmonella spp., and Staphylococcus aureus was determined. The study was performed using a three-period cross PK design following a 15-day washout period. In the first period, marbofloxacin (10 mg/kg) was administered by an intravenous (IV) injection. In the second and third periods, marbofloxacin was co-administered with ST (lactated ringer + 5% dextrose + 0.45% sodium chloride, IV, 20 ml/kg, dexamethasone 0.5 mg/kg, SC) and ST + LPS (E. coli O55:B5, 10 µg/kg), respectively. Plasma marbofloxacin concentration was measured using HPLC-UV. Following IV administration of marbofloxacin alone, the t 1 / 2 λ z , AUC0-∞ , ClT , and Vdss were 2.87 hr, 34.73 hr × µg/ml, 0.29 L hr-1  kg-1 , and 0.87 L/kg, respectively. While no change was found in the MBX + ST group in terms of the PK parameters of marbofloxacin, it was determined that the ClT of marbofloxacin decreased, AUC0-∞ increased, and t 1 / 2 λ z and MRT prolonged in the MBX + ST + LPS group. MIC values of marbofloxacin were 0.031 to >16 µg/ml for E. coli, 0.016 to >16 µg/ml for M. haemolytica, 0.016-1 µg/ml for P. multocida, 0.016-0.25 µg/ml for K. pneumoniae, 0.031-0.063 µg/ml for Salmonella spp., and 0.031-1 µg/ml for S. aureus. The study results show the necessity to make a dose adjustment of marbofloxacin following concomitant administration of ST in endotoxemic sheep. Also, the PK and pharmacodynamic effect of marbofloxacin needs to be determined in naturally infected septicemic sheep following concomitant administration of single and ST.

Basophil-derived tumor necrosis factor can enhance survival in a sepsis model in mice.

Basophils are evolutionarily conserved in vertebrates, despite their small numbers and short life span, suggesting that they have beneficial roles in maintaining health. However, these roles are not fully defined. Here we demonstrate that basophil-deficient mice exhibit reduced bacterial clearance and increased morbidity and mortality in the cecal ligation and puncture (CLP) model of sepsis. Among the several proinflammatory mediators that we measured, tumor necrosis factor (TNF) was the only cytokine that was significantly reduced in basophil-deficient mice after CLP. In accordance with that observation, we found that mice with genetic ablation of Tnf in basophils exhibited reduced systemic concentrations of TNF during endotoxemia. Moreover, after CLP, mice whose basophils could not produce TNF, exhibited reduced neutrophil and macrophage TNF production and effector functions, reduced bacterial clearance, and increased mortality. Taken together, our results show that basophils can enhance the innate immune response to bacterial infection and help prevent sepsis.

Bone Marrow Cells Transplant in Septic Mice Modulates Systemic Inflammatory Response via Cell-Cell Contact.

Sepsis is a dynamic disease, displaying an inflammatory profile that varies over time and for each organ. Controlling the inflammatory response based in targeting a single molecule has been proved useless. We hypothesized that treatment with bone marrow-derived mononuclear cells (BMDMCs) may be more efficient to modulate the systemic inflammatory response to infection. Adult male Balb/c mice were subjected to cecal ligation and puncture (CLP) or endotoxemia model of experimental sepsis. BMDMCs were separated under Ficoll gradient and injected intravenously 1 h after the procedures. Cytokines concentration was quantified in plasma, lungs, heart, and gut. Spleens, lymph nodes, and thymus were used for lymphocytes isolation and cell death assessment. All measurements were performed 2 h after BMDMCs injection. RAW264.7 macrophages and BMDMCs were cocultivated in vitro to investigate the mechanisms involved. Our data showed that an early single intravenous injection of BMDMCs in animals submitted to the murine model of endotoxemia led to the improvement of survival rate; BMDMCs persistency in lung, liver, and spleen after 24 h; decreased necrosis and apoptosis of mononuclear cells; lower TNF-α, but increased IL-10 concentration in plasma; and tissue-specific cytokine profile. In vitro experiments demonstrated that IL-6, IL-10, and nitric oxide production depends on direct contact of BMDMCs to macrophages and that TNF-α production is negatively regulated by PGE2. BMDMCs are efficient in protecting animals from endotoxemia and sepsis, reducing systemic inflammation as well as specifically modulating tissue inflammation, producing the necessary immune regulation to re-equilibrate the inflammatory response.

Modulation of neuroinflammation and memory dysfunction using percutaneous vagus nerve stimulation in mice.

BACKGROUND: The vagus nerve is involved in regulating immunity and resolving inflammation. Current strategies aimed at modulating neuroinflammation and cognitive decline, in many cases, are limited and ineffective. OBJECTIVE: We sought to develop a minimally invasive, targeted, vagus nerve stimulation approach (pVNS), and we tested its efficacy with respect to microglial activation and amelioration of cognitive dysfunction following lipopolysaccharide (LPS) endotoxemia in mice. METHODS: We stimulated the cervical vagus nerve in mice using an ultrasound-guided needle electrode under sevoflurane anesthesia. The concentric bipolar needle electrode was percutaneously placed adjacent to the carotid sheath and stimulation was verified in real-time using bradycardia as a biomarker. Activation of vagal fibers was confirmed with immunostaining in relevant brainstem structures, including the dorsal motor nucleus and nucleus tractus solitarius. Efficacy of pVNS was evaluated following administration of LPS and analyses of changes in inflammation and behavior. RESULTS: pVNS enabled stimulation of the vagus nerve as demonstrated by changes in bradycardia and histological evaluation of c-Fos and choline acetyltransferase expression in brainstem nuclei. Following LPS administration, pVNS significantly reduced plasma levels of tumor necrosis factor-α at 3 h post-injection. pVNS prevented LPS-induced hippocampal microglial activation as analyzed by changes in Iba-1 immunoreactivity, including cell body enlargement and shortened ramifications. Cognitive dysfunction following endotoxemia was also restored by pVNS. CONCLUSION: Targeted cervical VNS using this novel percutaneous approach reduced LPS-induced systemic and brain inflammation and significantly improved cognitive responses. These results provide a novel therapeutic approach using bioelectronic medicine to modulate neuro-immune interactions that affect cognition.

Exercise activates vagal induction of dopamine and attenuates systemic inflammation.

Physical exercise is one of the most important factors improving quality of life, but it is not feasible for patients with morbidity or limited mobility. Most previous studies focused on high-intensity or long-term exercise that causes metabolic stress or physiological adaption, respectively. Here, we studied how moderate-intensity swimming affects systemic inflammation in 6-8 week old C57BL/6J male mice during endotoxemia. One-hour swimming prevented hypokalemia, hypocalcemia, attenuated serum levels of inflammatory cytokines, increased anti-inflammatory cytokines but affected neither IL6 nor glycemia before or after the endotoxic challenge. Exercise attenuated serum TNF levels by inhibiting its production in the spleen through a mechanism mediated by the subdiaphragmatic vagus nerve but independent of the splenic nerve. Exercise increased serum levels of dopamine, and adrenalectomy prevented the potential of exercise to induce dopamine and to attenuate serum TNF levels. Dopaminergic agonist type-1, fenoldopam, inhibited TNF production in splenocytes. Conversely, dopaminergic antagonist type-1, butaclamol, attenuated exercise control of serum TNF levels. These results suggest that vagal induction of dopamine may contribute to the anti-inflammatory potential of physical exercise.

Frontline Science: Targeted expression of a dominant-negative high mobility group A1 transgene improves outcome in sepsis.

High mobility group (HMG) proteins are a family of architectural transcription factors, with HMGA1 playing a role in the regulation of genes involved in promoting systemic inflammatory responses. We speculated that blocking HMGA1-mediated pathways might improve outcomes from sepsis. To investigate HMGA1 further, we developed genetically modified mice expressing a dominant negative (dn) form of HMGA1 targeted to the vasculature. In dnHMGA1 transgenic (Tg) mice, endogenous HMGA1 is present, but its function is decreased due to the mutant transgene. These mice allowed us to specifically study the importance of HMGA1 not only during a purely pro-inflammatory insult of endotoxemia, but also during microbial sepsis induced by implantation of a bacterial-laden fibrin clot into the peritoneum. We found that the dnHMGA1 transgene was only present in Tg and not wild-type (WT) littermate mice, and the mutant transgene was able to interact with transcription factors (such as NF-κB), but was not able to bind DNA. Tg mice exhibited a blunted hypotensive response to endotoxemia, and less mortality in microbial sepsis. Moreover, Tg mice had a reduced inflammatory response during sepsis, with decreased macrophage and neutrophil infiltration into tissues, which was associated with reduced expression of monocyte chemotactic protein-1 and macrophage inflammatory protein-2. Collectively, these data suggest that targeted expression of a dnHMGA1 transgene is able to improve outcomes in models of endotoxin exposure and microbial sepsis, in part by modulating the immune response and suggest a novel modifiable pathway to target therapeutics in sepsis.

Endotoxemia Results in Trapping of Transfused Red Blood Cells in Lungs with Associated Lung Injury.

BACKGROUND: Red blood cell (RBC) transfusion is associated with organ failure, in particular in the critically ill. We hypothesized that endotoxemia contributes to increased trapping of RBCs in organs. Furthermore, we hypothesized that this effect is more pronounced following transfusion of stored RBCs compared with fresh RBCs. METHODS: Adult male Sprague-Dawley rats were randomized to receive injection with lipopolysaccharide from E coli or vehicle and transfusion with fresh or stored biotinylated RBCs. After 24 h, the amount of biotinylated RBCs in organs was measured by flow cytometry, as well as the 24-h post-transfusion recovery. Markers of organ injury and histopathology of organs were assessed. RESULTS: Endotoxemia resulted in systemic inflammation and organ injury. Following RBC transfusion, donor RBCs were recovered from the lung and kidney of endotoxemic recipients (1.2 [0.8-1.6]% and 2.2 [0.4-4.4]% of donor RBCs respectively), but not from organs of healthy recipients. Trapping of donor RBCs in the lung was associated with increased lung injury, but not with kidney injury. Stored RBCs induced organ injury in the spleen and yielded a lower 24-h post-transfusion recovery, but other effects of storage time were limited. CONCLUSION: Endotoxemia results in an increased percentage of donor RBCs recovered from the lung and kidney, which is associated with lung injury following transfusion.

Construction of a lentiviral vector containing shRNA targeting ADAM17 and its role in attenuating endotoxemia in mice.

Systemic inflammatory response syndrome is a pathophysiological inflammatory response mediated largely by tumor necrosis factor­α (TNF­α), in response to infectious or non­infectious stimuli. TNF­α secretion in response to bacterial lipopolysaccharide (LPS) is regulated in part by disintegrin and metalloproteinase domain­containing protein 17 (ADAM17). Therefore, the present study aimed to identify an effective inhibitor of ADAM17, in order to control inflammation and associated processes. In the present study, a lentiviral vector expressing short hairpin (sh)RNA targeting the ADAM17 gene was constructed. U937 cells were infected with the lentivirus and stimulated with LPS. ADAM17 expression was assessed by western blotting and TNF­α secretion was assessed by ELISA analysis. The lentivirus was additionally tested in vivo in a mouse model of endotoxemia and sTNF­α expression was assessed by flow cytometry in peritoneal macrophages. In vitro, the ADAM17 shRNA lentivirus reduced ADAM17 expression, and prevented TNF­α maturation in U937 cells. In vivo, mice exposed to the ADAM17 shRNA lentivirus prior to LPS­induced endotoxemia exhibited fewer signs of inflammation and less tissue damage compared with the control mice. In conclusion, the present study successfully constructed a shRNA lentiviral vector targeting the ADAM17 gene that exhibited apparent in vitro and in vivo effects on TNF­α processing in response to an LPS challenge. The results of the present study may aid the design and improvement of drugs designed to inhibit the function of ADAM17, and suggested a novel means of controlling inflammation and associated processes.

Prebiotics: A Novel Approach to Treat Hepatocellular Carcinoma.

Hepatocellular carcinoma is one of the fatal malignancies and is considered as the third leading cause of death. Mutations, genetic modifications, dietary aflatoxins, or impairments in the regulation of oncogenic pathways may bring about liver cancer. An effective barrier against hepatotoxins is offered by gut-liver axis as a change in gut permeability and expanded translocation of lipopolysaccharides triggers the activation of Toll-like receptors which stimulate the process of hepatocarcinogenesis. Prebiotics, nondigestible oligosaccharides, have a pivotal role to play when it comes to inducing an antitumor effect. A healthy gut flora balance is imperative to downregulation of inflammatory cytokines and reducing lipopolysaccharides induced endotoxemia, thus inducing the antitumor effect.

Nutritional Management of Metabolic Endotoxemia: A Clinical Review.

Context • Diet-induced, metabolic endotoxemia is emerging as an important contributory factor to the development of a wide range of chronic diseases, including cardiometabolic, autoimmune, psychiatric, and neurodegenerative illnesses. Emerging human clinical studies have demonstrated that diet and dietary components are potent modifiers of circulating endotoxins and can be used to reduce plasma levels significantly and improve metabolic health. Objective • The aim of the current study was to explore briefly the concept of metabolic endotoxemia and its relationship to disease development, to examine the influence of diet and dietary components on circulating endotoxins, and, finally, discuss the clinical relevance of nutritional interventions for management of metabolic endotoxemia. Design • The researcher performed a literature review of dietary and nutritional interactions with metabolic endotoxemia with a focus on studies relevant to clinical practice. Setting • The study took place at the UK College of Nutrition and Health (London, England). Results • Improving dietary quality, optimizing the intake of phytonutrient-rich foods, improving micronutrient status, consuming fermented foods, manipulating the gut microflora with prebiotics and probiotics, and using specific nutritional supplements, such as glutamine, lactoferrin, resveratrol, and berberine, have been shown to be effective in targeting metabolic endotoxemia. Conclusions • Diet, dietary components, and nutritional supplements, including prebiotics and probiotics, have demonstrated the ability to provide clinically important reductions in circulating endotoxins and improve related sequels, such as inflammation and other negative health markers. The development of personalized nutritional interventions for the management of metabolic endotoxemia is a promising area for future research due to the potential of such interventions to improve multiple aspects of human health and mitigate a wide range of chronic diseases.

Rat BMSC infusion was unable to ameliorate inflammatory injuries in tissues of mice with LPS-induced endotoxemia.

BACKGROUND: Mesenchymal stem cells (MSC) have been shown to have potent immunoregulatory effects. They are able to mitigate inflammation in many contexts of immune disorders, including autoimmune diseases and graft-versus-host disease (GVHD). Endotoxemia can induce systematic inflammation in the body. In this study, we try to investigate whether MSC can attenuate inflammation in models of LPS-induced endotoxemia. METHODS: Bone marrow MSC (BMSC) were isolated and expanded from rats of 4~6-week age. Adult mice were divided randomly into Control group, Model group and BMSC group. LPS were injected peritoneally into mice of Model group and BMSC group to induce endotoxemia. For BMSC group mice, 1×106 BMSC were injected through tail vein 1 hour after LPS application. Animals were sacrificed after 24 hours. Inflammatory damage in lungs and livers were detected through histochemistry. Wet/dry ratio of lung tissues was calculated, levels of inflammatory factors as IL-1ß and TNF-α in lung tissues were measured through ELISA. RESULTS: Inflammatory pathological changes in lung and liver in BMSC group were comparable to those in Model group. Moreover, in some animals, the injuries were exacerbated after BMSC treatment. Accordingly, wet/dry ratio of lung in BMSC group mice was higher than that in Model group mice. IL-1ß level in BMSC-treated group mice was significantly augmented, however, no significant changes were detected between these two groups for level of TNF-α. CONCLUSION: Our results showed that application of BMSC in LPS-induced endotoxemia models couldn't attenuate the inflammatory injuries in tissues. Although BMSC have been shown to be able to induce immune inhibition, however, in some instances, their immuno-inhibitory function might be regulated by the local environment.

Liver Injury and Endotoxemia in Male and Female Alcohol-Dependent Individuals Admitted to an Alcohol Treatment Program.

BACKGROUND: Interactions between the liver, the gut, and the immune system are critical components of alcoholic liver disease (ALD). The aim of this study was to explore the associations between alcohol-induced liver injury, endotoxemia, and inflammation at admission and over time during abstinence, as well as to examine the sex-related differences in these parameters in alcohol-dependent individuals admitted to an alcohol treatment program. METHODS: A cohort of 48 otherwise healthy participants with alcohol use disorder, but no clinical signs of alcoholic liver injury (34 males [M]/14 females [F]) admitted to an alcohol detoxification program, was stratified into 2 groups based on baseline plasma alanine aminotransferase (ALT) levels (as a marker of liver injury). Group 1 (ALT < 40 U/l, 7M/8F) and Group 2 (ALT ≥ 40 U/l, 27M/6F) were identified. Plasma biomarkers of liver damage, endotoxemia, and inflammation were examined at baseline, day 8, and day 15 of the admission. The drinking history was also evaluated. RESULTS: Sixty-nine percent of patients had elevated ALT and other markers of liver damage, including aspartate aminotransferase and cytokeratin 18 (CK18 M65 and CK M30) at baseline, indicating the presence of mild ALD. Elevated CK18 M65:M30 ratio suggested a greater contribution of necrotic rather than apoptotic hepatocyte cell death in the liver injury observed in these individuals. Females showed greater elevations of liver injury markers compared to males, although they had fewer drinks per day and shorter lifetime duration of heavy drinking. Liver injury was associated with systemic inflammation, specifically, elevated plasma tumor necrosis factor-alpha levels. Compared to patients without liver injury, patients with mild ALD had greater endotoxemia (increased serum lipopolysaccharide levels), which decreased with abstinence and this decrease preceded the drop in CK18 M65 levels. CONCLUSIONS: The study documented the association of mild alcohol-induced liver injury and endotoxemia, which improved with 2 weeks of abstinence, in a subset of individuals admitted to an alcohol detoxification program.

Inflammation-Induced Changes in Circulating T-Cell Subsets and Cytokine Production During Human Endotoxemia.

Observational clinical studies suggest the initial phase of sepsis may involve impaired cellular immunity. In the present study, we investigated temporal changes in T-cell subsets and T-cell cytokine production during human endotoxemia. Endotoxin (Escherichia coli lipopolysaccharide 4 ng/kg) was administered intravenously in 15 healthy volunteers. Peripheral blood and bronchoalveolar lavage fluid (BALF) were collected at baseline and after 2, 4, 6, 8, and 24 hours for flow cytometry. CD4+CD25+CD127lowFoxp3+ regulatory T cells (Tregs), CD4+CD161+ cells, and activated Human leukocyte antigen, HLA-DR+CD38+ T cells were determined. Ex vivo whole-blood cytokine production and Toll-like receptor (TLR)-4 expression on Tregs were measured. Absolute number of CD3+CD4+ (P = .026), CD3+CD8+ (P = .046), Tregs (P = .023), and CD4+CD161+ cells (P = .042) decreased after endotoxin administration. The frequency of anti-inflammatory Tregs increased (P = .033), whereas the frequency of proinflammatory CD4+CD161+ cells decreased (P = .034). Endotoxemia was associated with impaired whole-blood production of tumor necrosis factor-α, interleukin-10, IL-6, IL-17, IL-2, and interferon-γ in response to phytohaemagglutinin but did not affect TLR4 expression on Tregs. No changes in the absolute count or frequency of BALF T cells were observed. Systemic inflammation is associated with lymphopenia, a relative increase in the frequency of anti-inflammatory Tregs, and a functional impairment of T-cell cytokine production.

Transfusion of 35-day stored red blood cells does not result in increase of plasma non-transferrin bound iron in human endotoxemia.

BACKGROUND: Transfusion of a single unit of stored red blood cells (RBCs) has been hypothesized to induce supra-physiological levels of non-transferrin bound iron (NTBI), which may enhance inflammation and act as a nutrient for bacteria. We investigated the relation between RBC storage time and iron levels in a clinically relevant "two-hit" human transfusion model. STUDY DESIGN AND METHODS: Eighteen healthy male volunteers (ages 18-35 years) were infused with 2 ng lipopolysaccharide (LPS)/kg to induce systemic inflammatory response syndrome. Two hours later, each participant received either 1 unit of 2-day stored (2D) autologous RBCs, 35-day stored (35D) autologous RBCs, or an equal volume of saline. Every 2 hours up to 8 hours after LPS infusion, hemoglobin, hemolysis parameters, and iron parameters, including NTBI, were measured. RESULTS: Transfusion of both 2D and 35D RBCs caused increases in hemoglobin, plasma iron, and transferrin saturation; whereas levels remained stable in the saline group. Transfusion of 35D RBCs did not result in hemolysis nor did it lead to increased levels of NTBI compared with 2D RBCs or saline. LPS induced increases in ferritin, haptoglobin, bilirubin, and lactate dehydrogenase that were similar in all three groups. CONCLUSION: We conclude that 35D autologous RBCs do not cause hemolysis or increased levels of NTBI during human endotoxemia.

Long-term anti-endotoxin/E. coli efficacy in mice transfected with AAV2/1-muBPI25 -muFcγ1.

Bactericidal/permeability increasing (BPI) is an antibiotic protein which kills Gram-negative bacteria and neutralizes endotoxin. We have previously developed a recombinant adeno-associated virus which contains human BPI amino acid residues 1-199 and Fc fragment of human IgG1 gene (AAV-hBPI-Fc) and shown that the recombinant virus can protect mice from lethal endotoxemia. However, whether AAV-hBPI-Fc can be used in vivo for the long term remains unclear. To address this, we established an adeno-associated virus-containing mouse BPI and Fc fragment genes (muBPI-Fc) and compared antigenicity of these recombinant proteins in murine models. Immunohistochemistry showed the expression of both fusion proteins at injected sites. ELISA and Western blotting showed that the muBPI-Fc protein was detected in serum up to 8 weeks after injection, without generation of autoantibodies against muBPI-Fc. In contrast, expressed hBPI-Fc protein was only detected on the 2nd week, whereas the autoantibody against hBPI-Fc protein occurred in serum from the 4th week to the end of study. muBPI-Fc also reduced production of proinflammatory cytokines and protected mice from endotoxemia and bacteremia. Our data showed that AAV-muBPI-Fc has potential long-term efficacy as an anti-endotoxin and has anti-bacterial activity in mice, suggesting the potential clinical application of AAV-hBPI-Fc, such as in endotoxin shock.

Effects of bone marrow mesenchymal stem cells on the cardiac function and immune system of mice with endotoxemia.

The present study aimed to investigate the effects of bone marrow mesenchymal stem cells (MSCs) on the cardiac function and immune system of mice with endotoxemia. The mice were divided into the following groups: Control group, endotoxemia group, lipopolysaccharide (LPS) treatment group, LPS and MSC treatment group (LPS + MSC group) and MSC group. Following treatment with LPS, the cardiac function of the mice was examined at after 2, 6 and 24 h, and on day 7. An enzyme­linked immunofluorescent assay was used to analyze the serum and the levels of cytokines in the myocardium, and western blotting was used to investigate any changes in the levels of signaling proteins associated with the myocardium. A 3­(4,5­dimethyl­2­thiazolyl)­2,5­diphenyl­2H­tetrazolium bromide assay was used to investigate the growth rate of the splenic cells at after 24 h and on day 7, and the humoral immune function and phagocytosis of the macrophages in the mice were also examined. The cardiac function of the mice with endotoxemia declined, although this impairment was circumvented following treatment with MSCs. The levels of interleukin (IL)­1ß, IL­6, tumor necrosis factor­α and IL­10 in the serum and the myocardium increased following stimulation by LPS, although these declined as a result of MSC treatment. The expression levels of Toll­like receptor 4, p65­nuclear factor­κB and phosphorylated p38 in the mouse myocardium were enhanced following stimulation by LPS, which subsequently decreased as a result of MSC treatment. Compared with the control group, the growth rate of the splenic cells, humoral immune function and the level of phagocytosis of macrophages were all increased, although these parameters declined following treatment with MSCs. Taken together, the present study revealed that the MSCs inhibited the inflammatory reaction in the mice with endotoxemia, and improved cardiac function. By contrast, the cellular and humoral immunity were depressed, and phagocytosis of the macrophages, which were enhanced following simulation with LPS, were decreased following treatment with MSCs. However, no overexpression of the anti­inflammatory factor, IL­10, was observed. The present study hypothesized that MSCs exert a bifunctional role in endotoxemia, by inhibiting inflammatory factors, including IL­1 and IL­6, and inhibiting the compensatory expression of IL­10 following LPS stimulation. This avoids the possibility of excessive inhibition of immunological function, as this results in immunosuppression, and a higher ratio of IL­10 to TNF­α is indicative of a poor prognosis in patients with sepsis.