Endotoxins Of Gram-negative Bacteria Research Articles

Assessment of the significance of immunoenzyme test-system for determining antiendotoxic immunity against the endotoxin of gram negative bacteria

The purpose of the study was to determine the specificity and sensitivity of the immunoenzymatic test system that detects antibodies against the antigens of these bacteria in order to evaluate antiendotoxic immunity against GShPB endotoxins. It was found that flat bottom polystyrene solid phase carrier was selected for the proposed experimental test system for the detection of endotoxins of these bacteria by IFA method. The sensitivity of the recommended test system was 75% in colon dysbiosis, 76% in acute tonsillitis, 89% in acute bronchitis, and 95% in urinary tract infections, and the specificity was 5-25%, thus the diagnostic value of this test system it was proved for the first time.

Effects of Escherichia coli LPS Structure on Antibacterial and Anti-Endotoxin Activities of Host Defense Peptides.

The binding of Host Defense Peptides (HDPs) to the endotoxin of Gram-negative bacteria has important unsolved aspects. For most HDPs, it is unclear if binding is part of the antibacterial mechanism or whether LPS actually provides a protective layer against HDP killing. In addition, HDP binding to LPS can block the subsequent TLR4-mediated activation of the immune system. This dual activity is important, considering that HDPs are thought of as an alternative to conventional antibiotics, which do not provide this dual activity. In this study, we systematically determine, for the first time, the influence of the O-antigen and Lipid A composition on both the antibacterial and anti-endotoxin activity of four HDPs (CATH-2, PR-39, PMAP-23, and PMAP36). The presence of the O-antigen did not affect the antibacterial activity of any of the tested HDPs. Similarly, modification of the lipid A phosphate (MCR-1 phenotype) also did not affect the activity of the HDPs. Furthermore, assessment of inner and outer membrane damage revealed that CATH-2 and PMAP-36 are profoundly membrane-active and disrupt the inner and outer membrane of Escherichia coli simultaneously, suggesting that crossing the outer membrane is the rate-limiting step in the bactericidal activity of these HDPs but is independent of the presence of an O-antigen. In contrast to killing, larger differences were observed for the anti-endotoxin properties of HDPs. CATH-2 and PMAP-36 were much stronger at suppressing LPS-induced activation of macrophages compared to PR-39 and PMAP-23. In addition, the presence of only one phosphate group in the lipid A moiety reduced the immunomodulating activity of these HDPs. Overall, the data strongly suggest that LPS composition has little effect on bacterial killing but that Lipid A modification can affect the immunomodulatory role of HDPs. This dual activity should be considered when HDPs are considered for application purposes in the treatment of infectious diseases.

In sickness and in health: the dynamics of the fruit bat gut microbiota under a bacterial antigen challenge and its association with the immune response.

Interactions between the gut microbiome (GM) and the immune system influence host health and fitness. However, few studies have investigated this link and GM dynamics during disease in wild species. Bats (Mammalia: Chiroptera) have an exceptional ability to cope with intracellular pathogens and a unique GM adapted to powered flight. Yet, the contribution of the GM to bat health, especially immunity, or how it is affected by disease, remains unknown. Here, we examined the dynamics of the Egyptian fruit bats' (Rousettus aegyptiacus) GM during health and disease. We provoked an inflammatory response in bats using lipopolysaccharides (LPS), an endotoxin of Gram-negative bacteria. We then measured the inflammatory marker haptoglobin, a major acute phase protein in bats, and analyzed the GM (anal swabs) of control and challenged bats using high-throughput 16S rRNA sequencing, before the challenge, 24h and 48h post challenge. We revealed that the antigen challenge causes a shift in the composition of the bat GM (e.g., Weissella, Escherichia, Streptococcus). This shift was significantly correlated with haptoglobin concentration, but more strongly with sampling time. Eleven bacterial sequences were correlated with haptoglobin concentration and nine were found to be potential predictors of the strength of the immune response, and implicit of infection severity, notably Weissella and Escherichia. The bat GM showed high resilience, regaining the colony's group GM composition rapidly, as bats resumed foraging and social activities. Our results demonstrate a tight link between bat immune response and changes in their GM, and emphasize the importance of integrating microbial ecology in ecoimmunological studies of wild species. The resilience of the GM may provide this species with an adaptive advantage to cope with infections and maintain colony health.

CIM monolithic chromatography as a useful tool for endotoxin reduction and purification of bacteriophage particles supported with PAT analytics

Bacteriophages represent immense potential as therapeutic agents. Many of the most compelling applications of bacteriophages involve human therapy, some pertinent to gene therapy, others involving antibiotic replacement. Phages themselves are considered safe for humans. However, phage lysates may contain many kinds of harmful by-products, especially endotoxins of gram-negative bacteria and protein toxins produced by many pathogenic bacterial species. In bacteriophage research and therapy, most applications ask for highly purified phage suspensions, as such it is crucial to reduce proteins, endotoxins, DNA and other contaminants.In this article we present an efficient two-step chromatographic purification method for P. aeruginosa bacteriophage PP-01, using Convective Interaction Media (CIM®) monoliths, that is cGMP compliant and easy to scale-up for most stringent production of the therapeutic phage. First chromatographic step on CIMmultus OH resulted in 100% bacteriophage recovery with a reduction of 98 % protein and more than 99 % DNA content. Polishing was conducted using three different column options, CIMmultus with QA, H-Bond and PrimaS ligands. For PP-01 bacteriophage all three different options worked, but multimodal ligands H-Bond and PrimaS outperformed traditional QA in endotoxin removal (7 log step reduction). Additionally, an HPLC analytical method was developed to estimate phage concentration and impurity profile in different in-process samples. The HPLC method shows good correlation with drop assay titration, provides useful insights and can be run very fast with just 20 min per sample analysis.

Identification workflow of endotoxins by pyrolysis–gas chromatography–mass spectrometry based on a database and chemometrics

Single Shot Pyrolysis-Gas Chromatography-Mass Spectrometry (SS Py-GC-MS) has been previously demonstrated to directly evaluate the endotoxins of Gram-negative bacteria with minimal sample preparation. The analytical method was quick and sensitive, but data processing was time-consuming, especially when comparing two sets of data that were quite similar. In this research article, the data handling workflow was optimized, mainly using two approaches for comparing critical compound quantities to distinguish endotoxins from different sources. Firstly, a library of endotoxin biomarkers for bacteria profiling was constructed and the identification workflow was automated. Bacterial endotoxins could be fingerprinted down to the subspecies level. The approach was then tested on environmental, food, and water samples subjected to minimal sample preparation, and the results were highly promising. In the second approach, Chemometrics was utilized to create a similar but more encompassing database with predictive capability. The results supported the library technique, indicating that distinct bacteria species and subspecies produce endotoxins with varied amounts of each critical compound that could be identified using Py-GC-MS. A Hotelling T2 range plot was successful in differentiating Gram-negative bacterial endotoxins from Fungal mycotoxins and Cyanobacterial endotoxins. This illustrates the potential for the second approach for endotoxins which might not have been discovered. Additionally, the correlation between the molecular structure of lipopolysaccharides (LPS) and the endotoxin's virulence was observed for the first time, using a quantitative model of supervised Multivariate Analysis (MVA).

Role of epidermal growth factor receptor and microbial infections in polycystic kidney disease

Background: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a frequently inherited diseases associated with the presence of fluid-filled cysts. Epidermal Growth Factor Receptor (EGFR) plays role in cysts development
 Material and methods: The following tools (PubMed, PubMed Central, Medline Search Engine, Locate and Google Scholar) were used in literature search. Key words used to search for relevant literature are: Polycystic Kidney Disease, Epidermal Growth Factor Receptor, Tyrosine Kinase Inhibitor, Renal Cyst Formation and Renal Cyst Infection. The studies beyond 10 years were not included in present study.
 Analysis: The cross-examination of research papers allowed to analyse literature around role of EGFR in ADPKD pathophysiology, EGFR TKI as treatment of ADPKD and role of microbial cyst infections in disease progression.
 Results: There is a small body of literature that look at EGFR, Tyrosine Kinase Inhibitor (TKI) and cyst infection in ADPKD over the last decade. The ‘crosstalk’ between Src and EGFR was observed to have an impact on cyst development and progression. Therefore, the combined treatment with different compounds can be a desirable approach in the treatment of ADPKD. There has been observed relationship between cyst infections, decrease in kidney function and PKD gene mutation. Endotoxins of Gram-negative bacteria could be involved in disease development.
 Conclusion: The understanding of mechanisms of ADPKD and several cancers has led to the identification of molecular targets, and one of these is EGFR. The further study could establish the role of endotoxin in ADPKD development and its interaction with EGFR.

Cis-9, Trans-11 CLA Alleviates Lipopolysaccharide-Induced Depression of Fatty Acid Synthesis by Inhibiting Oxidative Stress and Autophagy in Bovine Mammary Epithelial Cells.

Lipopolysaccharide (LPS) is the dominating endotoxin of Gram-negative bacteria, which can cause mastitis. Bovine mammary epithelial cells (BMECs), as major components of the mammary gland, usually suffer LPS challenge. Cis-9, trans-11 conjugated linoleic acid (CLA) has been reported to have anti-inflammatory characteristics, while its anti-oxidative ability to maintain cellular homeostasis in BMECs under LPS challenge is limited. Therefore, we studied whether cis-9, trans-11 CLA can restore the disturbance of cellular homeostasis indicated by the redox status and autophagy level caused by LPS and have an effect on cellular function- milk fat metabolism. For oxidative stress, LPS challenge promoted the formation of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) and decreased the concentration of glutathione. Anti-oxidative signaling regulated by transcription factor nuclear factor, erythroid 2 like 2 (Nrf2) was also depressed by LPS at the mRNA and protein level. However, cis-9, trans-11 CLA pretreatment downregulated the formation of ROS and TBARS and upregulated the expression of antioxidative enzymes. As a part of innate immunity, autophagy was also motivated by LPS challenge, while CLA decreased the autophagy level. LPS and H2O2 inhibited milk fat synthesis-related transcription factor sterol regulatory element binding protein (SREBP1), peroxisome proliferator activated receptor gamma (PPARG) and their downstream enzymes. Furthermore, 50 uM cis-9, trans-11 CLA promoted the mRNA and protein abundance of milk fat synthesis-related genes and lipid droplet formation in BMECs. In conclusion, LPS challenge disturbed the cellular homeostasis and depressed milk fat synthesis in BMECs; while cis-9, trans-11 CLA alleviated oxidative stress and decreased autophagy level, thus promoting milk fat synthesis, which offers a natural therapeutic strategy for mastitis.

Mass Spectrometric Quantification of the Antimicrobial Peptide Pep19-2.5 with Stable Isotope Labeling and Acidic Hydrolysis

Sepsis is the number one cause of death in intensive care units. This life-threatening condition is caused by bacterial infections and triggered by endotoxins of Gram-negative bacteria that leads to an overreaction of the immune system. The synthetic anti-lipopolysaccharide peptide Pep19-2.5 is a promising candidate for the treatment of sepsis as it binds sepsis-inducing lipopolysaccharides and thus prevents initiation of septic shock. For clinical evaluation precise quantification of the peptide in blood and tissue is required. As the peptide is not extractable from biological samples by commonly used methods there is a need for a new analysis method that does not rely on extraction of the peptide. In order to quantify the peptide by mass spectrometry, the peptide was synthesized containing 13C9,15N1-labeled phenylalanine residues. This modification offers high stability during acidic hydrolysis. Following acidic hydrolysis of the samples, the concentration of 13C9,15N1-labeled phenylalanine determined by LC-MS could be unambiguously correlated to the content of Pep19-2.5. Further experiments validated the accuracy of the data. Moreover, the quantification of Pep19-2.5 in different tissues (as studied in Wistar rats) was shown to provide comparable results to the results obtained with radioactively-labeled (14C) Pep19-2.5- Radioactive labeling is considered as the gold standard for quantification of compounds that refrain from reliable extraction methods. This novel method represents a valuable procedure for the determination of Pep19-2.5 and sticky peptides with unpredictable extraction properties in general.

Variation, Modification and Engineering of Lipid A in Endotoxin of Gram-Negative Bacteria.

Lipid A of Gram-negative bacteria is known to represent a central role for the immunological activity of endotoxin. Chemical structure and biosynthetic pathways as well as specific receptors on phagocytic cells had been clarified by the beginning of the 21st century. Although the lipid A of enterobacteria including Escherichia coli share a common structure, other Gram-negative bacteria belonging to various classes of the phylum Proteobacteria and other taxonomical groups show wide variety of lipid A structure with relatively decreased endotoxic activity compared to that of E. coli. The structural diversity is produced from the difference of chain length of 3-hydroxy fatty acids and non-hydroxy fatty acids linked to their hydroxyl groups. In some bacteria, glucosamine in the backbone is substituted by another amino sugar, or phosphate groups bound to the backbone are modified. The variation of structure is also introduced by the enzymes that can modify electrostatic charges or acylation profiles of lipid A during or after its synthesis. Furthermore, lipid A structure can be artificially modified or engineered by the disruption and introduction of biosynthetic genes especially those of acyltransferases. These technologies may produce novel vaccine adjuvants or antagonistic drugs derived from endotoxin in the future.

Endotoxin measurements in the PM10 fraction of ambient air/Endotoxinmessungen in der PM10-Fraktion der Außenluft

As part of the outer cell wall of gram-negative bacteria endotoxins can be found ubiquitous in nature. So far most studies on airborne endotoxins focussed on occupational environments. In Germany IFA-Arbeitsmappe 9450 gives recommendations for sampling and analysis of endotoxins at workplaces. However, apart from background measurements for workplace evaluations, there are currently no guidelines in Germany for endotoxin measurements at environmental settings. Therefore, the aim of this study was to test whether PM10 sampling on filters with a high volume sampler and determination of endotoxin concentration via LAL assay are suitable methods for a new guideline for measurement of endotoxin concentration in ambient air. Over the course of one year endotoxin concentration was investigated at three different rural sampling spots. Annual median endotoxin concentration over all samples was 0.143 EU/m3. Between different sampling spots no significant differences in endotoxin concentrations were observed, yet endotoxin concentration in ambient air showed an obvious seasonal course. The applied methods have proven suitable for the analysis of endotoxins in the outdoor air, although further standardization is needed before implementation in a guideline.

Detection of Beta-Glucan Contamination in Nanotechnology-Based Formulations.

Understanding the potential contamination of pharmaceutical products with innate immunity modulating impurities (IIMIs) is essential for establishing their safety profiles. IIMIs are a large family of molecules with diverse compositions and structures that contribute to the immune-mediated adverse effects (IMAE) of drug products. Pyrogenicity (the ability to induce fever) and activation of innate immune responses underlying both acute toxicities (e.g., anaphylactoid reactions or pseudoallergy, cytokine storm) and long-term effects (e.g., immunogenicity) are among the IMAE commonly related to IIMI contamination. Endotoxins of gram-negative bacteria are the best-studied IIMIs in that both methodologies for and pitfalls in their detection and quantification are well established. Additionally, regulatory guidance documents and research papers from laboratories worldwide are available on endotoxins. However, less information is currently known about other IIMIs. Herein, we focus on one such IIMI, namely, beta-glucans, and review literature and discuss the experience of the Nanotechnology Characterization Lab (NCL) with the detection of beta-glucans in nanotechnology-based drug products.

Эндотоксиновый компонент патогенеза ВИЧ-инфекции

Механизм прогрессирования иммуносупрессии при ВИЧ-инфекции не может быть сведен лишь к гибели CD4+ лимфоцитов вследствие репликации в них вируса. Полученные в результате многочисленных исследований данные свидетельствуют о важной роли избыточной активации иммунной системы в патогенезе заболевания. В качестве одного из факторов, поддерживающих активацию иммунной системы и развитие у ВИЧ-инфицированных разной степени проявлений системного воспалительного ответа, рассматривается эндотоксин (ЭТ) грамотрицательных бактерий. Роль эндотоксина в этом процессе подтверждается высокими показателями эндотоксина и растворимого рецептора CD14 в крови, а также изменениями уровня эндотоксин-связывающих антител у большей части больных с ВИЧ-инфекцией, находящихся на разных стадиях заболевания. Поступлению избыточных количеств эндотоксина в кровоток способствует повреждение кишечной стенки, характерное для течения ВИЧ-инфекции с самого начала заболевания, наблюдающееся в течение всей жизни пациента, и не купирующееся полностью на фоне антиретровирусной терапии (АРВТ). Определенный вклад в микробную транслокацию могут вносить и нарушения микробиоценоза кишечника, так же весьма характерные для течения ВИЧ-инфекции. Продолжение исследований в данном направлении позволит разработать методы патогенетической терапии, которые в сочетании с АРВТ смогут повысить эффективность лечебных мероприятий и увеличить продолжительность жизни пациентов. The mechanism of immunosuppression progression in HIV infection cannot be reduced only to destruction of CD4+ lymphocytes due to the virus replication. Multiple studies have stressed an important role of immune system overactivation in the pathogenesis of the disease. Endotoxin of gram-negative bacteria is considered as one of the factors supporting the immune system activation and manifestations of the systemic inflammatory response of different severity in HIV-infected people. This fact is confirmed by high levels of endotoxin and soluble CD14 receptor as well as by changes in endotoxin-binding antibody titers in a vast majority of patients with HIV infection at different stages of the disease. Excessive amounts of endotoxin release into the blood due to damage of the intestinal wall, which is typical for the course of HIV infection from the disease onset throughout the patient’s life and cannot be completely reversed by antiretroviral therapy (ART). Disorders of the intestinal microbiocenosis, which are also very typical for the HIV infection, can also contribute to the microbial translocation. Further studies in this direction will allow developing methods for pathogenetic therapy, which in combination with ART would increase the effectiveness of therapeutic measures and prolong the life expectancy of patients.

Ethyl pyruvate inhibits LPS induced IPEC-J2 inflammation and apoptosis through p38 and ERK1/2 pathways

ABSTRACT The endotoxin of Gram-negative bacteria threatens the intestinal health of livestock. Ethyl pyruvate (EP) has been shown to regulate intestinal immunity and protect against cell and tissue damage. In this study, it was first verified that EP could reduce the secretion of IL-8, TNF-α, IL-6 and IL-1β in LPS-induced IPEC-J2 cells. Then, we used RNA sequencing (RNA-seq) to analyze the differentially expressed genes (DEGs) of inflammatory factors induced by LPS in IPEC-J2 cells. It was found that LPS induced the upregulation of 377 genes and the downregulation of 477 genes compared to Vehicle; LPS+EP induced the upregulation of 258 genes and the downregulation of 240 genes compared to Vehicle; and LPS+EP induced the upregulation of 373 genes and the downregulation of 188 genes compared to LPS (fold change > 1.5 and FDR < 0.01). Their enrichment pathways included the MAPK signaling pathway, PI3K-Akt signaling pathway, Toll-like receptor signaling pathway, and other pathways. Furthermore, the mRNA level of cytokines associated with inflammation and apoptosis enriched in the MAPK pathway was verified by qRT-PCR. Western blots and immunofluorescence revealed that EP significantly inhibited phosphorylated p38 and phosphorylated-ERK1/2 protein expression levels (P < 0.05). The apoptosis due to LPS reduced by EP was significantly inhibited, as shown by Annexin V-FITC/PI staining. According to the results, EP inhibited the expression of IL-8, TNF-α, IL-6 and IL-1β as well as apoptosis by inhibiting the phosphorylation of p38 and ERK1/2 in LPS-induced IPEC-J2 cells.

The Removal of Endo- and Enterotoxins From Bacteriophage Preparations.

The production of phages for therapeutic purposes demands fast, efficient and scalable purification procedures. Phage lysates have a wide range of impurities, of which endotoxins of gram-negative bacteria and protein toxins produced by many pathogenic bacterial species are harmful to humans. The highest allowed endotoxin concentration for parenterally applied medicines is 5 EU/kg/h. The aim of this study was to evaluate the feasibility of different purification methods in endotoxin and protein toxin removal in the production of phage preparations for clinical use. In the purification assays, we utilized three phages: Escherichia phage vB_EcoM_fHoEco02, Acinetobacter phage vB_ApiM_fHyAci03, and Staphylococcus phage vB_SauM_fRuSau02. The purification methods tested in the study were precipitation with polyethylene glycol, ultracentrifugation, ultrafiltration, anion exchange chromatography, octanol extraction, two different endotoxin removal columns, and different combinations thereof. The efficiency of the applied purification protocols was evaluated by measuring phage titer and either endotoxins or staphylococcal enterotoxins A and C (SEA and SEC, respectively) from samples taken from different purification steps. The most efficient procedure in endotoxin removal was the combination of ultrafiltration and EndoTrap HD affinity column, which was able to reduce the endotoxin-to-phage ratio of vB_EcoM_fHoEco02 lysate from 3.5 × 104 Endotoxin Units (EU)/109 plaque forming units (PFU) to 0.09 EU/109 PFU. The combination of ultrafiltration and anion exchange chromatography resulted in ratio 96 EU/109 PFU, and the addition of octanol extraction step into this procedure still reduced this ratio threefold. The other methods tested either resulted to less efficient endotoxin removal or required the use of harmful chemicals that should be avoided when producing phage preparations for medical use. Ultrafiltration with 100,000 MWCO efficiently removed enterotoxins from vB_SauM_fRuSau02 lysate (from 1.3 to 0.06 ng SEA/109 PFU), and anion exchange chromatography reduced the enterotoxin concentration below 0.25 ng/ml, the detection limit of the assay.

Changes in DNA integrity and gene expression in ovarian follicular cells of lipopolysaccharide-treated female mice.

Lipopolysaccharide (LPS), the endotoxin of gram-negative bacteria, can impair female reproductive function. However, there is a little information about genotoxic stress in ovarian follicular cells as well as about the changes in oocyte developmental potential under endotoxemia. So the aim of our study was to investigate in vitro oocyte maturation, the DNA damage and expression of some developmental competence-related genes in follicular cells of mice treated with LPS. LPS (3mg/kg) was intraperitoneally injected into the mice for 24h, and in vitro maturation of mouse oocyte was determined. The expression levels of genes in cumulus cells were detected by reverse transcriptase polymerase chain reaction. DNA damage in granulosa cells was assessed by the alkaline comet assay. LPS injection caused an impairment of oocyte maturation in vitro: the percentage of oocytes reaching metaphase I and metaphase II decreased markedly compared to vehicle control mice. At the same time we observed strong DNA damage in granulosa cells of LPS-treated animals. The endotoxemia resulted in significantly reduced mRNA expression levels for hyaluronan synthase 2 (HAS2), cyclooxygenase 2 (COX2) and Gremlin-1 (GREM1) genes compared with control. Our results obtained in a mouse model of endotoxin-induced female reproductive dysfunction suggest that LPS may affect oocyte quality through the induction of DNA damage and decreasing the cumulus expression of genes associated with cumulus expansion and oocyte maturation, such as HAS2, COX2 and GREM1.

Protective effect of germanium citrate in endotoxin-induced ovarian dysfunction in mice.

Now it is known that endotoxin of gram-negative bacteria – lipopolysaccharide (LPS) is associated with disturbances of reproductive function in women. To simulate an ovarian dysfunction in endotoxemia and to explore a possible protective action of germanium (Ge) citrate obtained via nanotechnology we used LPS administration into female mice (3 mg/kg). Treatment with LPS caused patho­logical changes in mouse ovaries at 24h post-injection: an impairment of oocyte maturation in vitro, DNA damage in granulosa cells (as estimated by DNA-comet assay) and a decrease in their viability by increasing both necrosis and apoptosis. Pretreatment of mice with Ge citrate (i.p. 100 mkg/kg, 2 injections: 24 h and 1 h before LPS) was effective to reduce genotoxic stress and cell death. Ge citrate administration to LPS-treated mice significantly enhanced oocyte quality (as indicated by improvement in oocyte maturation) that may be due to cytoprotective effect of this compound on surrounding follicular cells. Our results support potential therapeutic application of Ge citrate to improve reproductive function in endotoxemia.

BMSCs ameliorate septic coagulopathy by suppressing inflammation in cecal ligation and puncture-induced sepsis.

Sepsis is an aggressive and life-threatening systemic inflammatory response with a high mortality. Inflammation and coagulation play crucial roles in the pathogenesis of sepsis in a mutually promoting manner. Unlike other single-target molecular therapies that have no obvious effects on clinical sepsis, bone marrow stromal cell (BMSC) therapy offers a broader spectrum of activities ranging from immune and inflammation suppression to tissue regeneration. In this report, we demonstrate that BMSC injection attenuates septic coagulopathy. It decreased the mortality, mitigated lung injury and reduced the surge of proinflammatory factors in mice with sepsis induced by cecal ligation and puncture (CLP). An in vitro cell model also revealed that co-culture with BMSCs reduced secretion of proinflammatory factors and injury of endothelial cells in response to lipopolysaccharide (LPS), an endotoxin of gram-negative bacteria. Together, our results demonstrate that BMSCs suppress sepsis-induced inflammation, endothelial dysfunction and defective coagulation.

Gene-metabolite profile integration to understand the cause of spaceflight induced immunodeficiency

Spaceflight presents a spectrum of stresses very different from those associated with terrestrial conditions. Our previous study (BMC Genom. 15: 659, 2014) integrated the expressions of mRNAs, microRNAs, and proteins and results indicated that microgravity induces an immunosuppressive state that can facilitate opportunistic pathogenic attack. However, the existing data are not sufficient for elucidating the molecular drivers of the given immunosuppressed state. To meet this knowledge gap, we focused on the metabolite profile of spaceflown human cells. Independent studies have attributed cellular energy deficiency as a major cause of compromised immunity of the host, and metabolites that are closely associated with energy production could be a robust signature of atypical energy fluctuation. Our protocol involved inoculation of human endothelial cells in cell culture modules in spaceflight and on the ground concurrently. Ten days later, the cells in space and on the ground were exposed to lipopolysaccharide (LPS), a ubiquitous membrane endotoxin of Gram-negative bacteria. Nucleic acids, proteins, and metabolites were collected 4 and 8 h post-LPS exposure. Untargeted profiling of metabolites was followed by targeted identification of amino acids and knowledge integration with gene expression profiles. Consistent with the past reports associating microgravity with increased energy expenditure, we identified several markers linked to energy deficiency, including various amino acids such as tryptophan, creatinine, dopamine, and glycine, and cofactors such as lactate and pyruvate. The present study revealed a molecular architecture linking energy metabolism and immunodeficiency in microgravity. The energy-deficient condition potentially cascaded into dysregulation of protein metabolism and impairment of host immunity. This project is limited by a small sample size. Although a strict statistical screening was carefully implemented, the present results further emphasize the need for additional studies with larger sample sizes. Validating this hypothesis using an in vivo model is essential to extend the knowledge towards identifying markers of diagnostic and therapeutic value.

Chronic nicotine treatment decreases LPS signaling through NF-κB and TLR-4 modulation in the hippocampus

The hippocampus is a brain region that is rich in nicotinic acetylcholine receptors (nAChRs), especially the α7 subtype. The hippocampus is severely affected in disorders that have a neuroinflammatory component, such as Alzheimer’s disease, Parkinson’s disease, and schizophrenia. Previous studies demonstrated both in vivo and in vitro that nicotine inhibits immunological responses, including those that are triggered by the inflammatory agent lipopolysaccharide (LPS), the endotoxin of Gram-negative bacteria. The present study investigated whether chronically administered nicotine interferes with the nuclear binding of nuclear factor-κB (NF-κB) and the expression of LPS-induced inflammatory response genes. The results indicated that chronic nicotine administration (0.1mg/kg, s.c., 14days) inhibited the LPS-induced nuclear binding of NF-κB and mRNA expression levels of Tnf, Il1b, Nos2, and Tlr4. The presence of both the selective α7 nAChR antagonist methyllycaconitine (MLA; 5.0mg/kg i.p., 14days) and the nonselective nAChR antagonist mecamylamine (Meca; 1.0mg/kg, s.c., 14days) reversed the inhibitory effects of nicotine. These results suggest that the chronic activation of α7- and αxβy-containing nAChRs reduces acute inflammatory responses in the brain.

Prospects of correction of endotoxemia and metabolic syndrome comorbid with allergic dermatitis

Endotoxin of Gram-negative bacteria of the digestive tract, which has a high degree of toxicity to humans, is considered today as a factor in inducing allergic development and formation of combinedforms of atopic dermatitis (AD), is capable of a more severe disease. Increasing the level of endotoxin leads to the development of endogenous intoxication syndrome (EIS) that accompanies the disease, providing a damaging effect on the tissue and determining the prognosis of AD. At SEI complex metabolic disorders is forming that leads not only to a decrease in the volume of organs of the immune system, increase the permeability of natural barriers, but also to a defect interaction of its individual effector units. Excretion of endogenous and exogenous stimuli from the body at allergic dermatosis prevents the formation of secondary immune deficiency and the further development of the pathological process of the skin, contributing to its stabilization and sustainable long-term remission. Application of detoxifying drug “Eubikor” and general aerocryotherapy at atopic dermatitis leads to more intense reduction of SCORAD, reduces the frequency of exacerbations and increase duration of remission. Method of aerocryotherapy was used to stimulate the mechanisms of activation of metabolism and regeneration of damaged tissues. Clinical experience of “Eubikor” and aerocryotherapy rate in patients with atopic dermatitis is presented.