BACKGROUND: Endotoxin tolerance (ET) is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide (LPS) leads to dramatically elevated survival. Accumulating evidence has shown that peripheral T cells contribute to the induction of ET. However, what happens to T cell development in the thymus under ET conditions remains unclear. The purpose of this study was to analyze the alterations in thymocyte populations (double-positive [DP] and single-positive [SP] cells) under ET conditions. METHODS: Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups: a group examined 72 h after LPS injection (72-h group) and a group examined 8 days after LPS injection (8-day group). Injection of phosphate-buffered saline was used as a control (control group). Changes in thymus weight, cell counts, and morphology were detected in the three groups. Moreover, surface molecules such as CD4, CD8, CD44, CD69, and CD62L were analyzed using flow cytometry. Furthermore, proliferation, apoptosis, cytokine production, and extracellular signal-regulated kinase (ERK) pathway signaling were analyzed in thymocyte populations. The polymorphism and length of the T-cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) were analyzed using capillary electrophoresis DNA laser scanning analysis (ABI 3730). RESULTS: Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET. Moreover, the proportions of DP cells (control: 72.130 ± 4.074, 72-h: 10.600 ± 3.517, 8-day: 84.770 ± 2.228), CD4+ SP cells (control: 15.770 ± 4.419, 72-h: 44.670 ± 3.089, 8-day: 6.367 ± 0.513), and CD8+ SP cells (control: 7.000 ± 1.916, 72-h: 34.030 ± 3.850, 8-day: 5.133 ± 0.647) were obviously different at different stages of ET. The polymorphism and length of TCR β chain CDR3 also changed obviously, indicating the occurrence of TCR rearrangement and thymocyte diversification. Further analysis showed that the expression of surface molecules, including CD44, CD69, and CD62L, on thymocyte populations (DP and SP cells) were changed to different degrees. Finally, the proliferation, apoptosis, cytokine production, and ERK pathway signaling of thymocyte populations were changed significantly. CONCLUSION These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.
Animals ; CD4-Positive T-Lymphocytes ; Cell Differentiation ; Endotoxins/toxicity* ; Flow Cytometry ; Mice ; Signal Transduction ; Thymocytes ; Thymus Gland

Animals ; Apoptosis ; Endotoxins/toxicity* ; Heart/drug effects* ; MAP Kinase Signaling System ; Myocardium/pathology* ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing/metabolism*

BACKGROUNDAcute lung injury (ALI) is a serious and common condition for which there are currently no specific strategies for treatment. Recent studies have suggested that bone marrow-derived multipotent mesenchymal stem cells (MSCs) may have therapeutic applications in multiple clinical disorders. We explored the biological effects of MSCs during endotoxin-induced ALI and the mechanisms involved.

METHODSMSCs were isolated from male rat bone marrow and the ALI model was induced by intravenous endotoxin injection. Female rats were sacrificed at 6 hours, 24 hours, 4 days, 1 week and 3 weeks post-injection of MSCs or saline and the lung tissue, bronchoalveolar lavage fluid, and serum were harvested for analysis. We further evaluated the survival of the rats and examined the effects of endotoxin-induced injury on the interaction between alveolar macrophages (AMs) and MSCs in ex vivo.

RESULTSThere was a significant decrease in numbers of neutrophils in bronchoalveolar lavage fluid (P < 0.05), and myeloperoxidase activity in the lung (P < 0.01), and of TNF-α and IL-1β in serum (P < 0.05) in the MSC treated rats at 4 days. Furthermore, MSC treated rats exhibited improved survival, lower lung injury score, higher concentration of IL-10 in the serum and a reduced hydroxyproline content, but these differences were not statistically significant. Moreover, co-cultures of MSCs and AMs had significantly reduced levels of TNF-α, IL-1β and macrophage inflammatory protein (MIP)-1α and significantly increased levels of IL-10 (P < 0.05) in the culture supernatants.

CONCLUSIONSTreatment with intravenous injection of bone marrow-derived MSCs have beneficial effects on endotoxin-induced ALI in rats. The beneficial effect might be achieved through the engraftment of differentiated MSCs in the lungs and appears derive more from their capacity to secrete soluble factors that modulate immune responses.

Acute Lung Injury ; chemically induced ; metabolism ; therapy ; Animals ; Bone Marrow Cells ; cytology ; Cells, Cultured ; Coculture Techniques ; Endotoxins ; toxicity ; Female ; Lung ; metabolism ; pathology ; Macrophages, Alveolar ; cytology ; Male ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; physiology ; Peroxidase ; metabolism ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVESTo identify significantly differentially expression genes of steroid-induced femoral head necrosis (SINFH) of rats by gene chip, and to find out the potential factors and molecular mechanisms that oxidative stress originate or strengthen the SINFH.

METHODSTwenty Wistar rats were divided into experimental group and control group randomly. E. coli endotoxin was given to all rats at a dose of 20 µg/kg body weight by daily i.p. for two times. Then methylprednisolone (40 mg/kg) or saline was daily injected into the left gluteus muscle of the rats in experimental group and control group respectively. Six weeks later, the mRNA was extracted from the femoral head of rats in every group, and the cDNA were obtained by inverse transcript, then carried out microarray detection. The quantitative RT-PCR was used to confirm the result of microarray, and the differentially expressed genes were analyzed for the functional annotation by gene ontology (GO).

RESULTSCompared to the control group, 190 genes in the experimental group were differentially expressed, with 52 up-regulated and 138 down-regulated. Of these genes, 102 are known (have deposited in GeneBank), while 88 of them are unknown. The known genes can be divided into several families according to their biological functions, such as: oxidative stress, apoptosis, signal transduction, angiogenesis, extracellular matrix, lipid metabolism, and gene transcription related genes. The results of quantitative RT-PCR are consistent with gene-chip results.

CONCLUSIONSThe occurrence of SINFH is a complicated process affected by multiple factors and signaling pathways. Our findings indicate that many genes which are involved in different signaling pathways were differentially expressed between SINFH rats and normal rats.

Animals ; Endotoxins ; toxicity ; Female ; Femur Head Necrosis ; chemically induced ; genetics ; Gene Expression ; Genomics ; Male ; Oligonucleotide Array Sequence Analysis ; Prednisolone ; adverse effects ; Rats ; Rats, Wistar

BACKGROUNDAntithrombin-III (AT-III), the major inhibitor of thrombin in plasma, also has anti-inflammation property and might have positive effect on sepsis. The present study aimed to investigate the effects of AT-III on inflammatory reaction and pulmonary protection in endotoxin-induced acute lung injury (ALI) rat.

METHODSSixty male Sprague-Dawley rats were randomly assigned equally to normal control group, ALI group, AT-III treatment group, AT-III + heparin treatment group, and heparin treatment group. The pulmonary vascular permeability index (PVPI) was measured by single nuclide tracer technique. The activity of AT-III in plasma was determined by the method of synthetic chromogenic substrata. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels in serum were determined by enzyme-linked immunosorbent assay. The expressions of lung tissue mitogen-activated protein kinases (ERK1/2, P38 and JNK MAPK) were determined by Western blotting.

RESULTSRats had significantly improved lung histopathology in the AT-III treatment group and heparin treatment group compared with the ALI group. The PVPI of the ALI group was 0.38 + or - 0.04, significantly higher than that of the normal control group (0.20 + or - 0.02, P < 0.01), AT-III treatment group (0.30 + or - 0.04, P < 0.01) and heparin treatment group (0.28 + or - 0.04, P < 0.01) respectively. There were no significant differences of PVPI in the ALI group and AT-III + heparin treatment group. The activity of AT-III in plasma in the ALI group was (76 + or - 8)%, significantly lower than that of the normal control group ((96 + or - 11)%, P < 0.05) and AT-III treatment group ((105 + or - 17)%, P < 0.05) respectively. The serum levels of TNF-alpha and IL-6 of the ALI group were (2.770 + or - 0.373) microg/L and (1.615 + or - 0.128) ng/ml respectively, significantly higher than those of the normal control group ((0.506 + or - 0.093) microg/L and (0.233 + or - 0.047) ng/ml respectively, all P < 0.01), AT-III treatment group ((1.774 + or - 0.218) microg/L and (1.140 + or - 0145) ng/ml respectively, all P < 0.01) and heparin treatment group ((1.924 + or - 0.349) microg/L and (1.223 + or - 0.127) ng/ml respectively, all P < 0.01). The lung tissue levels of phospho-ERK1/2 and phospho-P38 MAPK expressions were markedly higher in the ALI group than in the normal control group, AT-III treatment group and heparin treatment group respectively.

CONCLUSIONSAT-III without concomitant heparin inhibited the activation of ERK1/2 and P38 MAPK, down-regulated the levels of downstream cytokines TNF-alpha and IL-6, relieved endothelial permeability, and improved the ALI in endotoxin-induced rats. It might be helpful to administrate AT-III alone, not with concomitant heparin, to those patients with ALI and sepsis.

Acute Lung Injury ; chemically induced ; drug therapy ; enzymology ; pathology ; Animals ; Anti-Inflammatory Agents ; therapeutic use ; Antithrombin III ; therapeutic use ; Endotoxins ; toxicity ; Heparin ; therapeutic use ; Lung ; drug effects ; metabolism ; pathology ; Male ; Mitogen-Activated Protein Kinases ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe whether electroacupuncture (EA) at Zusanli (ST 36) reduces endotoxin-induced hepatic injury in rats and to explore the mechanism.

METHODSForty male SD rats were randomly divided into 4 groups, a endotoxin group, an EA group, a normal group and a non-acupoint group. Hepatic injury rat model was prepared by injection of endotoxin (5 mg/kg) into the caudal vein, the normal group received the injection of the equal amount of saline; for the EA group, EA (2-100 Hz, 2 mA, 1.5 h) was given at "Zusanli" (ST 36) half an hour after modeling, and for the non-acupoint group, acupuncture was given at the point 5 mm lateral to and 5 mm below "Zusanli" (ST 36), and other treatments were as same as those in the EA group.

RESULTSInjection of endotoxin into the caudal vein could significantly increase TNF-alpha content in the liver and plasma ALT activity (P<0.01), which were decreased by EA (P<0.01) and were not significantly changed in the non-acupoint group (P>0.05).

CONCLUSIONThe abnormal increases of TNF-alpha content in the liver and plasma ALT activity induced by endotoxin can be decreased by EA at "Zusanli" (ST 36), protecting the organ, and the mechanism is possibly related with the decrease of TNF-alpha content in the liver.

Acupuncture Points ; Alanine Transaminase ; blood ; Animals ; Electroacupuncture ; Endotoxins ; toxicity ; Liver ; drug effects ; Male ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; analysis

OBJECTIVETo study the protective effect of soybean protease inhibitor on LPS-induced lung injury in rats.

METHODFifty male SD rats were randomly divided in five groups, 10 rats in each group as sham-operation group, model control group, positive medicine group, and high, moderate SBTI groups. Except the sham-group, other groups were induced by intratracheal instillation of LPS with a dose of 6 mg x kg(-1). All rats were given drug throughout intraperitoneal injection except the model controlled group, the positive medicine group was given PMSF with a dose of 50 mg x kg(-1), the high dose group of SBTI was given SBTI with a dose of 100 mg x kg(-1), a dose of the moderate group is 50 mg x kg(-1). We examined all rats in seven days. Index exam: cell quantity, activity of neutrophilic granulocyte released elastic protease proteins in BALF, histopathological examination and so on.

RESULTSoybean protease inhibitor can level down the level of total protein, cell quantity, PMN percent, activity of neutrophilic granulocyte in BALF. SBTI level down the content of NF-kappa B in nucleoprotein, while increase the content of I kappa B alpha in plasmoprotein.

CONCLUSIONSBTI is useful in protecting experimental pulmonary injury induced by LPS in rats.

Acute Lung Injury ; chemically induced ; drug therapy ; metabolism ; pathology ; Animals ; Endotoxins ; toxicity ; Granulocytes ; drug effects ; metabolism ; pathology ; I-kappa B Proteins ; metabolism ; Male ; NF-KappaB Inhibitor alpha ; Rats ; Soybeans ; chemistry ; Transcription Factor RelA ; metabolism ; Trypsin Inhibitors ; pharmacology

A quantitative structure-property relationship (QSPR) model in terms of amino acid composition and the activity of Bacillus thuringiensis insecticidal crystal proteins was established. Support vector machine (SVM) is a novel general machine-learning tool based on the structural risk minimization principle that exhibits good generalization when fault samples are few; it is especially suitable for classification, forecasting, and estimation in cases where small amounts of samples are involved such as fault diagnosis; however, some parameters of SVM are selected based on the experience of the operator, which has led to decreased efficiency of SVM in practical application. The uniform design (UD) method was applied to optimize the running parameters of SVM. It was found that the average accuracy rate approached 73% when the penalty factor was 0.01, the epsilon 0.2, the gamma 0.05, and the range 0.5. The results indicated that UD might be used an effective method to optimize the parameters of SVM and SVM and could be used as an alternative powerful modeling tool for QSPR studies of the activity of Bacillus thuringiensis (Bt) insecticidal crystal proteins. Therefore, a novel method for predicting the insecticidal activity of Bt insecticidal crystal proteins was proposed by the authors of this study.
Algorithms ; Amino Acids ; genetics ; Animals ; Artificial Intelligence ; Bacterial Proteins ; classification ; genetics ; toxicity ; Cell Survival ; drug effects ; Coleoptera ; growth & development ; Diptera ; growth & development ; Endotoxins ; classification ; genetics ; toxicity ; Hemolysin Proteins ; classification ; genetics ; toxicity ; Insect Control ; methods ; statistics & numerical data ; Insecticides ; toxicity ; Lepidoptera ; growth & development ; Models, Biological ; Reproducibility of Results ; Toxicity Tests ; methods ; statistics & numerical data

OBJECTIVETo observe the binding power of polymyxin B (PMB) and its simulation peptide to lipopolysaccharide (LPS) and lipoid A.

METHODSLPS and lipoid A were separately coated on biosensor. 5 microl of PMB (0.01 microg/L) 5 microl of its simulating peptide 1 (PMBSP1 0.01 microg/L) and 5 microl of its simulating peptide 2 (PMBSP2, 0.01 microg/L) were respectively added into the hydrophobic sample pool. The combining power of PMB and its simulating peptides PMBSP1 and PMBSP2 to LPS and lipoid A was compared. RESULTS (1) PMBSP1 almost did not bind LPS and lipoid A, while PMB and PMBSP2 possessed high affinity with LPS and lipoid A. (2) The peak value (98.41 +/- 7.31) rad/s of PMBSP2 binding LPS was much higher than that (83.58 +/- 5.42) rad/s of PMB in binding LPS (P < 0.05). While the peak value of PMB in binding lipoid A was similar to that of PMBSP2. (3) The peak value of PMB binding LPS was significantly lower than that of PMB in binding lipoid A (P < 0.05). But there was no difference between the peak value of PMBSP2 in binding LPS and that of PMBSP2 in binding lipoid A. (4) PMBSP2 could bind to LPS and lipoid A in a shorter time to reach peak levels.

CONCLUSIONCompared with PMB, the PMBSP2 could bind to LPS and lipoid A in a shorter time. In addition, PMBSP2 exhibited similar affinity to LPS and lipoid A. This indicated that PMBSP might possess better anti-LPS activity due to its lack of space steric hindrance when PMBSP binding the lipoid A of LPS.

Cell Wall ; chemistry ; Endotoxins ; Gram-Negative Bacteria ; Lipopolysaccharides ; chemistry ; toxicity ; Peptides ; chemistry ; pharmacology ; Polymyxin B ; chemistry ; pharmacology

OBJECTIVETo observe the effect of sevoflurane on membrane permeability of alveolar capillaries in rats with acute lung injury and the ratio of inflammatory cells in bronchoalveolar lavage fluid in rats with acute endotoxin lung injury.

METHODS48 Wistar rats were selected and divided into group C, L, S1L and S2L after injection evans blue 50 mg/kg in random with 12 rats in each group. Group C was taken as control group, 1.2 ml normal saline was injected into the rats via femoral vein and then the rats were mechanically ventilated for 4 hours; The rats in group L were also mechanically ventilated for 4 hours after injection of endotoxin 5 mg/kg via the same vein. For the rats in group S1L and S2L, 1.0 or 1.5 minimal alveolar concentration (MAC) sevoflurane was inhaled with mechanical ventilation after injection of endotoxin 5 mg/kg. Evans blue was not injected into 6 rats of each group in order that the 6 rats could be used for pathological examination and alveoli lavage, lung pathomorphological score of the lung, lung wet/dry weight ratio, the content of lung water, lung permeability index, content of evans blue, total amount and ratio of inflammatory cells in bronchoalveolar lavage fluid (BALF) were all determined.

RESULTSSevoflurane of 1.0 MAC and 1.5 MAC made lung wet/dry weight ratio and content of lung water change insignificantly; lung permeability index, content of evans blue and pathomorphological score in group S1L decreased from 4.86 +/- 0.82, 112.21 +/- 11.44 ng/mg, 9.17 +/- 0.90 to 3.98 +/- 0.50, 92.85 +/- 11.80 ng/mg, 7.50 +/- 0.96; group S2L decreased to 3.91 +/- 0.34, 96.33 +/- 8.79 ng/mg, 7.67 +/- 0.75. Sevoflurane of 1.0 MAC and 1.5 MAC did not have a significantly effect on total amount and ratio of inflammatory cells in BALF.

CONCLUSIONMembrane permeability of alveolar capillaries after acute endotoxin lung injury decreased by inhalation of sevoflurane of 1.0 MAC and 1.5 MAC and pathological injury of lung tissue relieved.

Animals ; Blood-Air Barrier ; drug effects ; physiology ; Bronchoalveolar Lavage Fluid ; cytology ; Capillary Permeability ; drug effects ; physiology ; Endotoxins ; toxicity ; Female ; Male ; Methyl Ethers ; pharmacology ; Rats ; Rats, Wistar ; Respiratory Distress Syndrome, Adult ; chemically induced ; pathology ; physiopathology