1.Effects of glutamine on alpha-sarcomeric actin and its mRNA expression of myocardium in rats with endotoxemia.
Hong WANG ; Jing-kun PAN ; Mei SUN ; Zhuo ZHOU ; Hong GAO
Chinese Journal of Pediatrics 2005;43(12):925-929
OBJECTIVEEndotoxemia is a serious syndrome resulting in multi-organ failure. Once it happens, the penetration of small intestine epithelium increases, body liquid losses, then effective circulating blood decreases and serious metabolic acidosis, serious hypotension, systolic failure, and even shock may occur. In this pathological process, endotoxin, tumor necrosis alpha and systolic dysfunction play important roles. Nowadays, many studies have been done to resolve the systolic dysfunction, but too much attention had been paid to the followings: the depressions of myocardium caused by tumor necrosis alpha, other inflammatory factors, endotoxin and metabolic acidosis; the disturbance of blood vessel-nerve regulations; nitric oxide (NO)/inducible nitric oxide synthase (iNOS) over-synthesis and the decreased density of beta-receptors in the myocardium and/or their activities. Little attention has been paid to the relationship between alpha sarcmeric actin (alpha-SA) and systolic dysfunction during endotoxemia. Glutamine (Gln) can be metabolized into glutathione, an eliminator of free radical. It has been used in preventing myocardial damage from reperfusion. This study aimed to observe the dynamic changes of alpha-SA and mRNA expressions in rats with endotoxemia and examine the effects of Gln on them.
METHODSClassical rat model of endotoxemia was established by intraperitoneal injection of LPS (4 mg/kg, Escherichia coli O55:B5, Sigma). 121 Wistar 18-day-rats were divided into three groups randomly, (1) 0 h control group (normal saline: 1 ml/kg, n = 11). (2) LPS group (LPS: 4 mg/kg, n = 55). (3) Gln group (LPS: 4 mg/kg and immediately 13.64%; Gln: 1 ml/kg, Fresenus, n = 55), Furthermore, LPS and Gln groups were divided into 2, 4, 6, 24 and 72 h time points (n = 11). Each time point of LPS and Gln as well as control rats were anaesthetized at each time point with 1% chloral hydrate injected intraperitoneally at the dosage of 1 ml/kg. Then rats were sacrificed at appoint time, and the hearts were isolated. Eight of them were put in 76 degrees C liquid nitrogen and then frozen in minute 80 degrees C icebox in order to measure the expression of alpha-SA mRNA by RT-PCR. Three of them were fixed in 4% formaldehydum polymerisatum for 12 to 16 h, then the expression of alpha-SA was detected by immunohistochemistry.
RESULTS(1) Compared to 0 h, the expressions of alpha-SA and mRNA in LPS group were significantly depressed (P < 0.01). In LPS group, the lowest was at 6 - 24 h, while in Gln group, it was postponed to 24 h. At 72 h, there was no difference in expressions of alpha-SA between Gln and 0 h group (P > 0.05). (2) Comparing at same time point, the expressions of alpha-SA were significant higher in Gln group than those in LPS group, while the expressions of alpha-SA mRNA in Gln group were high at 4-72 h. There was, however, no significant difference at early phase (P > 0.05).
CONCLUSIONAlpha-SA and its mRNA expression were depressed in LPS-induced endotoxemia, especially from 6 to 24 h. It could damage the systolic function. alpha-SA decrease in endotoxemia was due to the inhibited synthesis other than the promoted degradation. Glutamine could inhibit the effects of LPS on both alpha-SA and its mRNA expressions.
Actins ; metabolism ; Animals ; Endotoxemia ; metabolism ; Glutamine ; pharmacology ; Lipopolysaccharides ; Myocardium ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar
2.LPS-induced endothelial cytoskeleton remodeling in human lung vessels and related miRNAs-profiling.
Yuzhen LYU ; Wenqin YU ; Yulu YANG ; Xiaolan XUE ; Haibin MA ; Xiaowei MA
Chinese Journal of Cellular and Molecular Immunology 2023;39(7):592-598
Objective To investigate the effects of lipopolysaccharide (LPS) on human pulmonary vascular endothelial cells (HPVECs) cytoskeleton and perform biological analysis of the microRNA (miRNA) spectrum. Methods The morphology of HPVECs was observed by microscope, the cytoskeleton by FITC-phalloidin staining, and the expression of VE-cadherin was detected by immunofluorescence cytochemical staining; the tube formation assay was conducted to examine the angiogenesis, along with cell migration test to detect the migration, and JC-1 mitochondrial membrane potential to detect the apoptosis. Illumina small-RNA sequencing was used to identify differentially expressed miRNAs in NC and LPS group. The target genes of differentially expressed miRNAs were predicted by miRanda and TargetScan, and the functional and pathway enrichment analysis was performed on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Further biological analysis of related miRNAs was carried out. Results After the LPS got induced, the cells became round and the integrity of cytoskeleton was destroyed. The decreased expression of VE-cadherin was also observed, along with the decreased ability of angiogenesis and migration, and increased apoptosis. Sequencing results showed a total of 229 differential miRNAs, of which 84 miRNA were up-regulated and 145 miRNA were down-regulated. The target gene prediction and functional enrichment analysis of these differential miRNA showed that they were mainly concentrated in pathways related to cell connection and cytoskeleton regulation, cell adhesion process and inflammation. Conclusion In vitro model of lung injury, multiple miRNAs are involved in the process of HPVECs cytoskeleton remodeling, the reduction of barrier function, angiogenesis, migration and apoptosis.
Humans
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Lipopolysaccharides/pharmacology*
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Endothelial Cells/metabolism*
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MicroRNAs/metabolism*
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Lung/metabolism*
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Cytoskeleton
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Gene Expression Profiling
3.Establishing the model of kappaB-decoy inhibiting the activity of NF-kappaB in PC12 cells.
Dong-mei WANG ; De-zheng GONG ; Sheng-ming YIN ; De-qin YU ; Hong XU ; Jing XU ; Jie ZHAO ; Yi-ping SUN
Chinese Journal of Applied Physiology 2010;26(2):195-198
OBJECTIVEObserving the time course and establishing the model of kappaB-decoy oligodeoxynucleotides (rcB-decoy) inhibiting the activity of NF-kappaB in the PC12 cells.
METHODSPC12 cells cultivating in the 6 wells plate were divided into 3 groups, experimental group: adding kappaB-decoy complex (6 microg DNA/well), the control group: adding scrambled-decoy complex, the normal group: adding lipid-Lipofectamine 2000, transfer and cultivate 48 h, then lipopolysaccharide (LPS, 200 ng/ml) was added in the cells for 0.5-4 h. The immunocytochemistry and Western blot were used to measure the expression or the activity of NF-kappaB in PC12 cells.
RESULTSIn PC12 cells, compared with normal group, the expression of NF-kappaB enhanced obviously with the time of the stimulation of LPS in scrambled-decoy treated control group (P < 0.01), in 2-4 h the level reached the peak; the expression of NF-kappaB showed the stable level with the time of the stimulation of LPS in kappaB-decoy treated experimental group, compared with the control group, the expression levels were obviously lower than the respective time point of control groups (P < 0.01).
CONCLUSIONkappaB-decoy could reduce the expression of NF-kappaB in the normal PC12 cells and inhibit the activity of NF-cB in the pathologic PC12 cells.
Animals ; Cells, Cultured ; Lipopolysaccharides ; pharmacology ; NF-kappa B ; antagonists & inhibitors ; metabolism ; Oligodeoxyribonucleotides ; pharmacology ; PC12 Cells ; Rats
4.Effects of exogenous carbon monoxide-releasing molecule 2 intervention in vitro on formation of human neutrophil extracellular traps stimulated by endotoxin/lipopolysaccharide and its mechanism.
Mingming SONG ; Xu WANG ; Weiting QIN ; Mingfeng ZHUANG ; Xiaohan XU ; Yisen ZHANG ; Bingwei SUN
Chinese Journal of Burns 2016;32(2):82-88
OBJECTIVETo explore the effects of exogenous carbon monoxide-releasing molecule 2 (CORM-2) on formation of human neutrophil extracellular traps (NETs) stimulated by endotoxin/lipopolysaccharide (LPS) and its relevant mechanism.
METHODSVenous blood samples were collected from a healthy adult volunteer to isolate neutrophils. The neutrophils were divided into normal control (NC) group, LPS group, LPS+ 10 μmol/L CORM-2 group, LPS+ 50 μmol/L CORM-2 group, and LPS+ inactive CORM-2 (iCORM-2) group according to the random number table. No treatment was given to the neutrophils in NC group. The neutrophils in LPS group underwent LPS stimulation (1 μL, 1 μg/mL). The neutrophils in LPS+ 10 μmol/L CORM-2 group, LPS+ 50 μmol/L CORM-2 group, and LPS+ iCORM-2 group underwent the same LPS stimulation as that in LPS group and treatment of 10 μmol/L CORM-2, 50 μmol/L CORM-2, and 50 μmol/L iCORM-2, respectively, with the volune of 1 μL. After conventional culture for 1 h, the number of NETs was determined with propidium iodide staining method; the early cell apoptosis rate was determined with flow cytometer; the generation level of reactive oxygen species (ROS) was assessed with dihydrogenrhodamine 123 fluorescent probe staining method (denoted as mean fluorescence intensity); the expression level of phosphorylated extracellular regulated kinase 1/2 (p-ERK1/2) was determined by Western blotting. The sample numbers of each group in the 4 experiments were all 5. Data were processed with one-way analysis of variance and SNK test.
RESULTS(1) The numbers of NETs per 400-time visual field in cells of LPS and LPS+ iCORM-2 groups were close to the number in NC group (with P values above 0.05). The number of NETs per 400-time visual field was significantly larger in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups than in NC and LPS groups (with P values below 0.05). The number of NETs per 400-time visual field in cells of LPS+ iCORM-2 group was close to that of LPS group (P>0.05). (2) The early cell apoptosis rate was significantly increased in LPS, LPS+ 10 μmol/L CORM-2, LPS+ 50 μmol/L CORM-2, and LPS+ iCORM-2 groups than in NC group (with P values below 0.05). The early cell apoptosis rates in LPS+ 10 μmol/L CORM-2, LPS+ 50 μmol/L CORM-2, and LPS+ iCORM-2 groups were close to the rate in LPS group (with P values above 0.05). (3) The generation level of ROS was significantly higher in cells of LPS, LPS+ 10 μmol/L CORM-2, and LPS+ iCORM-2 groups than in NC group (with P values below 0.05). The generation level of ROS in cells of LPS+ 50 μmol/L CORM-2 group was close to that of NC group (P>0.05). The generation level of ROS was lower in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups than in LPS group (with P values below 0.05), while the generation level of ROS in cells of LPS+ iCORM-2 group was close to that of LPS group (P>0.05). (4) The expression levels of p-ERK1/2 in cells of LPS and LPS+ iCORM-2 groups (respectively 0.0311±0.001 and 0.0309±0.0018) were close to the level in NC group (0.0304±0.0046, with P values above 0.05). The expression level of p-ERK1/2 was significantly higher in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups (respectively 0.7891±0.0201 and 1.2970±0.0056) than in NC group (with P values below 0.05). The expression level of p-ERK1/2 was significantly higher in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups than in LPS group (with P values below 0.05). The expression level of p-ERK1/2 in cells of LPS+ iCORM-2 group was close to that of LPS group (P>0.05).
CONCLUSIONSCORM-2 can obviously increase the production of NETs in LPS-induced neutrophils, and it might be attributable to the promotion of inhibition of ROS generation and phosphorylation of ERK1/2.
Apoptosis ; Carbon Monoxide ; metabolism ; Extracellular Traps ; Humans ; Lipopolysaccharides ; pharmacology ; Organometallic Compounds ; pharmacology ; Phosphorylation ; drug effects
6.Suppressed Production of Pro-inflammatory Cytokines by LPS-Activated Macrophages after Treatment with Toxoplasma gondii Lysate.
Eun Jung LEE ; Yoo Mi HEO ; Jong Hak CHOI ; Hyun Ouk SONG ; Jae Sook RYU ; Myoung Hee AHN
The Korean Journal of Parasitology 2008;46(3):145-151
During Toxoplasma gondii infection, macrophages, dendritic cells, and neutrophils are important sources of pro-inflammatory cytokines from the host. To counteract the pro-inflammatory activities, T. gondii is known to have several mechanisms inducing down-regulation of the host immunity. In the present study, we analyzed the production of proand anti-inflammatory cytokines from a human myelomonocytic cell line, THP-1 cells, in response to treatment with T. gondii lysate or lipopolysaccharide (LPS). Treatment of THP-1 cells with LPS induced production of IL-12, TNF-alpha, IL-8, and IL-10. Co-treatment of THP-1 cells with T. gondii lysate inhibited the LPS-induced IL-12, IL-8 and TNF-alpha expression, but increased the level of IL-10 synergistically. IL-12 and IL-10 production was down-regulated by anti-human toll-like receptor (TLR)-2 and TLR4 antibodies. T. gondii lysate triggered nuclear factor (NF)-kappaB-dependent IL-8 expression in HEK293 cells transfected with TLR2. It is suggested that immunosuppression induced by T. gondii lysate treatment might occur via TLR2-mediated NF-kappaB activation.
Animals
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Cell Line
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Cytokines/*biosynthesis
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Humans
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Inflammation/metabolism
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Lipopolysaccharides/*pharmacology
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Macrophages/*drug effects/*metabolism
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Toxoplasma
7.Role of autophagy in lipopolysaccharide-induced apoptosis of odontoblasts.
Huacui XIONG ; Ke CHEN ; Meimei LI
Journal of Southern Medical University 2020;40(12):1816-1820
OBJECTIVE:
To investigate the role of autophagy in lipopolysaccharide (LPS)-induced apoptosis of murine odontoblasts.
METHODS:
Murine odontoblasts (mDPC-23 cells) were treated with 5 μg/mL LPS for 6, 12 and 24 h, and the changes in cell viability was examined using CCK8 kit and cell apoptosis was detected by TUNEL staining. The changes in the protein levels of LC3, Beclin1, Atg5, AKT, p-AKT, mTOR and p-mTOR were detected using Western blotting. The effect of 3-MA treatment for 24 h on LPS-induced apoptosis of mDPC-23 cells was evaluated by detecting the expressions of apoptosis-related proteins caspase-3 and Bax using Western blotting.
RESULTS:
Stimulation with LPS for 6 and 12 h did not cause significant changes in the proliferation or apoptosis of mDPC-23 cells, but LPS treatment for 24 h significantly suppressed cell proliferation (
CONCLUSIONS
LPS stimulation induces autophagy to promote apoptosis of mDPC-23 cells, and suppression of autophagy attenuates LPS-induced apoptosis. Autophagy may play an important role in the injury of inflamed pulp tissues.
Animals
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Apoptosis
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Autophagy
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Lipopolysaccharides/pharmacology*
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Mice
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Odontoblasts/metabolism*
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Proto-Oncogene Proteins c-akt/metabolism*
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Signal Transduction
8.Coactivator p300-induced H3K27 acetylation mediates lipopolysaccharide-induced inflammatory mediator synthesis.
Ke HU ; Xiang Yu CAO ; Yu Xian LI ; Ling Li LIU ; Yue Fu CHEN ; Li Jun CHEN ; Min Jiang HUANG ; Bi Feng TAN ; Hui Ming YIN
Journal of Southern Medical University 2022;42(3):321-329
OBJECTIVE:
To investigate the role of acetylated modification induced by coactivator p300 in lipopolysaccharide (LPS)- induced inflammatory mediator synthesis and its molecular mechanism.
METHODS:
Agilent SurePrint G3 Mouse Gene Expression V2 microarray chip and Western blotting were used to screen the molecules whose expression levels in mouse macrophages (RAW246.7) were correlated with the stimulation intensity of LPS. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (chip-qPCR) were used to verify the binding of the molecules to the promoters of IL-6 and TNF-α genes. The effects of transfection of RAW246.7 cells with overexpression or interfering plasmids on IL-6 and TNF-α synthesis were evaluated with ELISA, and the binding level of the target molecules and acetylation level of H3K27 in the promoter region of IL-6 and TNF-α genes were analyzed by chromatin immunoprecipitation sequencing technique (chip-seq).
RESULTS:
Gene microarray chip data and Western blotting both confirmed a strong correlation of p300 expression with the stimulation intensity of LPS. Immunocoprecipitation confirmed the binding between p300 and c-myb. The results of EMSA demonstrated that c-myb (P < 0.05), but not p300, could directly bind to the promoter region of IL-6 and TNF-α genes; p300 could bind to the promoters only in the presence of c-myb (P < 0.05). The expressions of p65, p300 and c-myb did not show interactions. Both p300 overexpression and LPS stimulation could increase the level of promoter-binding p300 and H3K27 acetylation level, thus promoting p65 binding and inflammatory gene transcription; such effects were obviously suppressed by interference of c-myb expression (P < 0.05). Interference of p65 resulted in inhibition of p65 binding to the promoters and gene transcription (P < 0.05) without affecting p300 binding or H3K27 acetylation level.
CONCLUSION
LPS can stimulate the synthesis of p300, whose binding to the promoter region of inflammatory genes via c-myb facilitates the cohesion of p65 by inducing H3K27 acetylation, thus promoting the expression of the inflammatory genes.
Acetylation
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Animals
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Inflammation Mediators
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Interleukin-6/metabolism*
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Lipopolysaccharides/pharmacology*
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Mice
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Tumor Necrosis Factor-alpha/metabolism*
9.Platelet-rich Plasma Induces M2 Macrophage Polarization via Regulating AMPK Singling Pathway.
Lin-Ying SHI ; Yan-Hui LI ; Jing-Jing XU ; Yu ZHANG ; Ting-Ting XIE ; Yu-Bing XU ; Gui-Qiu SHAN ; Mou ZHOU
Journal of Experimental Hematology 2023;31(5):1486-1491
OBJECTIVE:
To investigate the role of platelet-rich plasma (PRP) in inducing the M2 macrophage polarization via regulating AMPK singling pathway.
METHODS:
The expressions of M1 marker CD11c and M2 marker CD206 in macrophages of blank control group, LPS group, LPS+PRP group, and LPS+PRP+Compound C group were detected by flow cytometry. Western blot was used to observe the effects of PRP on the expression of AMPK-mTOR signaling pathway-related proteins at different times (12 h, 18 h and 24 h) after LPS treatment. RNA interference technology was used to silence the expression of AMPK in macrophages, and the expression of TGF-β protein was subsequently examined by Western blot.
RESULTS:
LPS significantly reduced the expression of CD206 and increased the expression of CD11c (P <0.05). After the addition of PRP, the expression of CD206 was significantly increased (P <0.05), while the expression of CD11c was significantly decreased (P <0.05). Compared with LPS group, PRP treatment significantly increased the expressions of p-AMPK and p-ULK1 proteins at 12 h, 18 h and 24 h, while significantly decreased the expression of p-mTOR protein (P <0.05). After the addition of AMPK inhibitor Compound C, the expression of CD206 was significantly reduced (P <0.05) and the expression of CD11c was significantly increased compared with LPS+PRP group (P <0.05). After silencing the expression of AMPK in macrophages, the promotion effect of PRP on TGF-β was significantly reduced (P <0.05).
CONCLUSION
PRP can stimulate the transformation of macrophages to M2 type via AMPK signalling pathway.
Humans
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AMP-Activated Protein Kinases/pharmacology*
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Lipopolysaccharides/pharmacology*
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Macrophages/metabolism*
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Transforming Growth Factor beta/metabolism*
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Platelet-Rich Plasma/metabolism*
10.Decreased number of CD14+TLR4+ monocytes and their impaired cytokine responses to lipopolysaccharide in patients with chronic kidney disease.
Zhi LIU ; Yan-hong KAN ; Yu-dan WEI ; Xiu-jiang LI ; Fan YANG ; Yue HOU ; Yu-jun DU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2015;35(2):206-211
This study aimed to examine the number of circulating Toll-like receptor 4 (TLR4) + CD14+ monocytes in patients with different stages of chronic kidney disease (CKD), their responses to lipopolysaccharide (LPS), and to explore the potential association of the number of TLR4+CD14+ monocytes with clinical laboratory measures. The numbers of TLR4+CD14+, LPS-stimulated TNF-α+CD14+ and interleukin (IL)-6+CD14+ monocytes were determined by flow cytometry in 9 patients with stage 3 CKD, 11 with stage 4 CKD, 16 with stage 5 CKD, and 19 healthy controls (HCs). Their laboratory tests were performed by routine methods and the potential association among these measures was analyzed by Pearson's correlation analysis. The numbers of CD14+, CD14+TLR4+, LPSstimulated TNF-α+CD14+ and IL-6+CD14+ monocytes in patients with CKD were significantly less than those of HCs (all P<0.05), and were negatively associated with patient disease severity. The number of CD14+TLR4+ monocytes was positively correlated with estimated glomerular filtration rate (eGFR, P<0.001) and the levels of hematocrit (P<0.01), but negatively correlated with the levels of blood urine nitrogen, serum creatinine, and C-reactive protein (P<0.001 for all), in the CKD patients. Our data indicate that significant reduction in the number of TLR4+ monocytes and their impaired responses to LPS may be associated with the progression of CKD in Chinese patients.
Cytokines
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metabolism
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Humans
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Kidney Failure, Chronic
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metabolism
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Lipopolysaccharide Receptors
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metabolism
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Lipopolysaccharides
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pharmacology
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Monocytes
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metabolism
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Toll-Like Receptor 4
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metabolism