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1.
Opt Express ; 32(2): 1176-1187, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38297675

ABSTRACT

We propose a fast quality of transmission (QoT) estimation method based on cascaded artificial neural networks (ANNs) for intensity modulation-direct detection (IMDD) systems. The proposed method can calculate the bit error rate of three-span 36 km transmission within 0.7 seconds while taking account of the deterministic waveform distortion caused by the chromatic dispersion and self-phase modulation (SPM).

2.
Opt Express ; 30(26): 48030-48041, 2022 Dec 19.
Article in English | MEDLINE | ID: mdl-36558718

ABSTRACT

This paper investigates an auxiliary management and control channel (AMCC) signal extraction method using digital signal processing (DSP) blocks with 3-step moving averaging that allows a single coherent receiver to receive main signal and AMCC signal simultaneously. Receiver sensitivity characteristics versus the modulation index (MI) and average number of the proposed DSP blocks are elucidated. Based on the results, we discuss a policy for designing the parameters. Experiments apply the design policy to achieve receiver sensitivity of -41.8 dBm with both 25 Gbit/s QPSK main signal and 128 kbit/s AMCC signal; the main signal sensitivity penalty is just 0.2 dB.

3.
Opt Express ; 29(11): 17499-17509, 2021 May 24.
Article in English | MEDLINE | ID: mdl-34154291

ABSTRACT

This paper introduces the concept of a symmetric 10 Gbit/s high power-budget TDM-PON based on digital coherent technology and confirms its feasibility through a bidirectional transmission experiment with a transmission distance of 40 km and power budget of more than 50 dB. Burst-mode upstream 10 Gbit/s binary-phase-shift-keying (BPSK) signals synchronized by the clock recovered from downstream 10 Gbit/s NRZ signals are detected by using an optical pre-amplifier and coherent detection based on real-time burst-mode digital signal processing (DSP) in the optical line terminal (OLT). The real-time DSP implements coefficient handover in the adaptive equalizer to allow the reception of burst-mode upstream BPSK signals with short preamble length. An experimental bit error performance evaluation of the real-time burst-mode DSP yields the receiver sensitivity of -45.1 dBm for upstream burst-mode BPSK with a preamble length of 1.3 µs. For downstream signals, the receiver sensitivity of -38.9 dBm is achieved by using a chirp-controlled transmitter with optical post-amplifier so as to avoid the signal distortion created by the chromatic dispersion of single mode fiber (SMF) when the launched power is increased.

4.
Int J Mol Sci ; 22(3)2021 Jan 31.
Article in English | MEDLINE | ID: mdl-33572604

ABSTRACT

Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength that occurs with aging or in association with various diseases. The condition is prevalent worldwide and occurs more frequently in patients with chronic diseases owing to the intrinsic relationship of muscles with glucose, lipid, and protein metabolism. Liver cirrhosis is characterized by the progression of necro-inflammatory liver diseases, which leads to fibrosis, portal hypertension, and a catabolic state, which causes loss of muscle tissue. Sarcopenia is of significant concern in the state of liver cirrhosis because sarcopenia has been associated with higher mortality, increased hospital admissions, worse post-liver transplant outcomes, decreased quality of life, and increased risk for other complications associated with cirrhosis. Therefore, sarcopenia is also an important feature of liver cirrhosis, representing a negative prognostic factor and influencing mortality. An increased understanding of sarcopenia could lead to the development of novel therapeutic approaches that could help improve the cognitive impairment of cirrhotic patients; therefore, we present a review of the mechanisms and diagnosis of sarcopenia in liver disease and existing therapeutic approaches.


Subject(s)
Liver Diseases/diagnosis , Sarcopenia/diagnosis , Humans , Hyperammonemia/complications , Hyperammonemia/diagnosis , Hyperammonemia/therapy , Liver Cirrhosis/complications , Liver Cirrhosis/diagnosis , Liver Cirrhosis/therapy , Liver Diseases/complications , Liver Diseases/therapy , Liver Transplantation , Quality of Life , Sarcopenia/complications , Sarcopenia/genetics , Sarcopenia/therapy
5.
Biochem Biophys Res Commun ; 530(4): 665-672, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32768187

ABSTRACT

The role of sphingosine 1-phosphate (S1P) and its sphingosine-1-phosphate receptors (S1PRs) in non-alcoholic steatohepatitis (NASH) is unclear. We aimed to analyze the role of S1P/S1PRs in a Melanocortin-4 receptor (Mc4r)-deficient NASH murine model using FTY720, the functional antagonist of S1PR1, S1PR3, S1PR4, and S1PR5, and JTE-013, the antagonist of S1PR2. We observed that, compared to that in the control, the mRNA of S1pr1 tended to decrease, whereas those of S1pr2 and S1pr3 significantly increased in Mc4r-knockout (KO) mice subjected to a Western diet (WD). While the fat area did not differ, fibrosis progression differed significantly between control mice and mice in which liver S1PRs were blocked. Lipidomic and metabolomic analysis of liver tissues showed that JTE-013-administered mice showed elevation of S-adenosyl-l-methionine level, which can induce aberrant methylation due to reduction in glycine N-methyltransferase (GNMT) and elevation in diacylglycerol (DG) and triacylglycerol (TG) levels, leading to increased susceptibility to hepatocellular carcinoma (HCC). These phenotypes are similar to those of Gnmt-KO mice, suggesting that blocking the S1P/S1PR2 axis triggers aberrant methylation, which may increase DG and TG, and hepatocarcinogenesis. Our observations that the S1P/S1PR2 axis averts HCC occurrence may assist in HCC prevention in NASH.


Subject(s)
Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology , Non-alcoholic Fatty Liver Disease/pathology , Sphingosine-1-Phosphate Receptors/metabolism , Animals , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Disease Models, Animal , Disease Progression , Gene Expression Regulation , Glycine N-Methyltransferase/genetics , Glycine N-Methyltransferase/metabolism , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Receptor, Melanocortin, Type 4/genetics , Receptor, Melanocortin, Type 4/metabolism , Sphingosine-1-Phosphate Receptors/antagonists & inhibitors , Sphingosine-1-Phosphate Receptors/genetics
6.
Hepatol Res ; 49(10): 1244-1248, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31077507

ABSTRACT

Hepatitis E virus (HEV) infection has been recognized as an acute condition. However, recent reports have shown that immunocompromised patients, such as those receiving solid-organ transplantation, can develop chronic hepatitis with HEV infection. We report two cases of chronic hepatitis E after kidney transplantation (KT) who were successfully treated with ribavirin monotherapy. Several years after KT, both patients had sustained elevations in the levels of liver enzymes for a period of more than 6 months. Both patients had HEV infection, genotype 3a. Histological studies showed infiltration of inflammatory cells without fibrosis. Treatment included ribavirin monotherapy at a dosage of 600 mg daily for 3 months. One month after therapy initiation, HEV-RNA turned to negative, and remained negative at 24 weeks after ribavirin therapy without severe complications. Although the treatment of chronic hepatitis E is not fully established, ribavirin therapy can be a safe and effective treatment for chronic hepatitis E.

7.
Immunopharmacol Immunotoxicol ; 36(2): 145-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24506665

ABSTRACT

The effect of lipopolysaccharide (LPS) on insulin sensitivity in adipocytes were examined by using differentiated 3T3-L1 adipocytes. Insulin-mediated activation of insulin receptor substrate (IRS) 1/2 was inhibited in LPS-pretreated adipocytes and IRS1/2-mediated Akt activation was also attenuated in those cells. LPS inhibited activation of glycogen synthase kinase 3 as a negative regulator of glycogenesis and impaired the glycogen synthesis in response to insulin. LPS-induced activation of phosphoinositide 3-kinase (PI3K) in adipocytes. Involvement of suppressor of cytokine signaling 3 (SOCS3) in LPS-induced IRS1/2 inhibition was excluded. Considering that both insulin and LPS were able to activate the PI3K/Akt signaling pathway, LPS was suggested to impair insulin sensitivity of adipocytes through down-regulating insulin-mediated PI3K/Akt activation.


Subject(s)
Adipocytes/drug effects , Insulin Resistance/physiology , Insulin/metabolism , Lipopolysaccharides/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , 3T3-L1 Cells , Adipocytes/metabolism , Animals , Cell Line , Glycogen Synthase Kinase 3/metabolism , Insulin Receptor Substrate Proteins/metabolism , Mice , Signal Transduction/drug effects , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolism
8.
Immunology ; 140(3): 352-61, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23826757

ABSTRACT

The effect of Pam3CSK4, a Toll-like receptor 2 (TLR2) ligand, on interferon-γ (IFN-γ) -induced nitric oxide (NO) production in mouse vascular endothelial END-D cells was studied. Pre-treatment or post-treatment with Pam3CSK4 augmented IFN-γ-induced NO production via enhanced expression of an inducible NO synthase (iNOS) protein and mRNA. Pam3CSK4 augmented phosphorylation of Janus kinase 1 and 2, followed by enhanced phosphorylation of signal transducer and activator of transcription 1 (STAT1) at tyrosine 701. Subsequently, the enhanced STAT1 activation augmented IFN-γ-induced IFN-regulatory factor 1 expression leading to the iNOS expression. Pam3CSK4 also induced the activation of p38 and subsequent phosphorylation of STAT1 at serine 727. A pharmacological p38 inhibitor abolished the augmentation of IFN-γ-induced NO production by Pam3CSK4. Surprisingly, Pam3CSK4 enhanced a physical association of MyD88 and IFN-γ receptor. Together, these findings suggest that Pam3CSK4 up-regulates IFN-γ signalling in vascular endothelial cells via the physical association between MyD88 and IFN-γ receptor α, and p38-dependent serine 727 STAT1 phosphorylation.


Subject(s)
Endothelium, Vascular/drug effects , Lipopeptides/pharmacology , Myeloid Differentiation Factor 88/metabolism , Nitric Oxide Synthase Type II/metabolism , Nitric Oxide/metabolism , Receptors, Interferon/metabolism , Toll-Like Receptor 2/agonists , Animals , Cell Line , Endothelium, Vascular/immunology , Gene Expression Regulation/drug effects , Interferon-Stimulated Gene Factor 3/metabolism , Interferon-gamma/immunology , MAP Kinase Kinase 4/metabolism , MAP Kinase Signaling System/drug effects , Mice , Nitric Oxide Synthase Type II/genetics , Phosphorylation/drug effects , Protein Binding , p38 Mitogen-Activated Protein Kinases/metabolism , Interferon gamma Receptor
9.
Cell Immunol ; 282(2): 100-5, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23770718

ABSTRACT

The effect of lipopolysaccharide (LPS) on valproic acid (VPA)-induced cell death was examined by using mouse RAW 264.7 macrophage cells. LPS inhibited the activation of caspase 3 and poly (ADP-ribose) polymerase and prevented VPA-induced apoptosis. LPS inhibited VPA-induced p53 activation and pifithrin-α as a p53 inhibitor as well as LPS prevented VPA-induced apoptosis. LPS abolished the increase of Bax/Bcl-2 ratio, which is a critical indicator of p53-mediated mitochondrial damage, in response to VPA. The nuclear factor (NF)-κB inhibitors, Bay 11-7082 and parthenolide, abolished the preventive action of LPS on VPA-induced apoptosis. A series of toll-like receptor ligands, Pam3CSK4, poly I:C, and CpG DNA as well as LPS prevented VPA-induced apoptosis. Taken together, LPS was suggested to prevent VPA-induced apoptosis via activation of anti-apoptotic NF-κB and inhibition of pro-apoptotic p53 activation. The detailed inhibitory mechanism of VPA-induced apoptosis by LPS is discussed.


Subject(s)
Apoptosis/drug effects , Lipopolysaccharides/pharmacology , NF-kappa B/metabolism , Tumor Suppressor Protein p53/metabolism , Valproic Acid/pharmacology , Animals , Cell Line , Dose-Response Relationship, Drug , Immunoblotting , Lipopeptides/pharmacology , Macrophages/cytology , Macrophages/drug effects , Macrophages/metabolism , Mice , NF-kappa B/antagonists & inhibitors , Nitriles/pharmacology , Oligodeoxyribonucleotides/pharmacology , Poly I-C/pharmacology , Proto-Oncogene Proteins c-bcl-2/metabolism , Sesquiterpenes/pharmacology , Sulfones/pharmacology , Toll-Like Receptor 9/agonists , Toll-Like Receptors/agonists , bcl-2-Associated X Protein/metabolism
10.
DEN Open ; 2(1): e63, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35310733

ABSTRACT

Objectives: Diversion colitis (DC) is an inflammatory disorder caused by interruption of the fecal stream and subsequent nutrient deficiency from luminal bacteria. The utility of fecal microbiota transplantation (FMT) for DC was recently investigated; however, the precise pathogenesis of this condition remains unclear. This study aimed to evaluate the utility of autologous FMT in DC and to determine the related changes in the intestinal microbiota. Methods: Autologous FMT was performed to reestablish the intestinal microbiota in five patients (average age, 64.6 ± 8.3 years) with DC. They underwent double-ended colostomy. We assessed the diverted colon by endoscopy and evaluated the microbiota before and after FMT using the 16S rRNA gene sequencing method. Results: All five patients had mild inflammation (ulcerative colitis endoscopic index of severity [UCEIS] 2-3) in the diverted colon based on the colonoscopic findings. Three patients presented with symptoms, such as tenesmus, mucoid stool, and bloody stool. With FMT treatment, all patients achieved endoscopic remission (UCEIS score of 0 or 1) and symptomatic improvement. We observed a significantly decreased α-diversity in DC patients compared to healthy controls. The frequency of aerobic bacteria, such as Enterobacteriaceae, in the diverted colon decreased after autologous FMT. Conclusions: This study was the first to show that the microbiota in the diverted colon was significantly affected by autologous FMT. Since interruption of the fecal stream is central to the development of DC, FMT can be considered a promising treatment.

11.
Cancer Immunol Immunother ; 60(10): 1439-46, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21644032

ABSTRACT

An ADP ribosylation factor-GTPase activating protein (ASAP1) is highly expressed in a variety of tumor cells and is involved in the cell motility, invasion, and metastasis. In order to elucidate the involvement of ASAP1 in lipopolysaccharide (LPS)-mediated inflammatory response, the effect of ASAP1 silencing on LPS-induced proinflammatory mediators production was examined by using RAW 264.7 macrophage-like cells. ASAP1 was constitutively expressed in the cells and the expression was augmented by LPS stimulation. Silencing of ASAP1 with small interfering RNA enhanced the production of tumor necrosis factor-α, interleukin 6, interferon-ß, and nitric oxide in response to LPS. ASAP1 silencing augmented the activation of nuclear factor (NF)-κB and several mitogen-activated protein kinases (MAPKs). On the other hand, ASAP1 silencing did not affect the expression of IRAK4, TRAF6, and Akt as the upstream molecules of NF-κB signaling. A series of toll-like receptor ligands as well as LPS augmented the ASAP1 expression. Taken together, ASAP1 was suggested to negatively regulate LPS-induced proinflammatory mediators production through down-regulating LPS signaling. The feedback function of ASAP1 in LPS-mediated inflammatory response is discussed.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Lipopolysaccharides/immunology , Signal Transduction/immunology , Adaptor Proteins, Signal Transducing/metabolism , Animals , Cell Line , Cytokines/biosynthesis , Cytokines/immunology , Immunoblotting , Inflammation/immunology , Inflammation/metabolism , Macrophages/immunology , Macrophages/metabolism , Mice , RNA, Small Interfering , Reverse Transcriptase Polymerase Chain Reaction
12.
Cell Immunol ; 270(1): 19-24, 2011.
Article in English | MEDLINE | ID: mdl-21477797

ABSTRACT

Thalidomide is known as an anti-angiogenic, anti-tumor, and anti-proliferative agent, widely used in the treatment of some immunological disorders and cancers. The effect of thalidomide on interferon (IFN)-γ induced nitric oxide (NO) production in mouse vascular endothelial cells was examined in order to elucidate the anti-angiogenic or anti-inflammatory action. Thalidomide inhibited IFN-γ-induced NO production in mouse END-D cells via reduced expression of an inducible type of NO synthase (iNOS) protein and mRNA. Since thalidomide did not alter the cell surface expression of IFN-γ receptor, the NO inhibition was suggested to be due to the impairment of IFN-γ-induced intracellular event by thalidomide. Thalidomide inhibited the phosphorylation of IRF1, which was required for the iNOS expression. Moreover, it inhibited the phosphorylation of STAT1, an upstream molecule of IRF1, in IFN-γ signaling. Thalidomide did not inhibit the JAK activation in response to IFN-γ. A phosphatase inhibitor, sodium orthovanadate, abolished the inhibitory action of thalidomide. Therefore, thalidomide was suggested to inhibit IFN-γ-induced NO production via impaired STAT1 phosphorylation.


Subject(s)
Endothelial Cells/metabolism , Thalidomide/pharmacology , Angiogenesis Inhibitors/pharmacology , Animals , Cell Line , Endothelial Cells/cytology , Endothelial Cells/drug effects , Interferon-gamma/metabolism , Interferon-gamma/pharmacology , Mice , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/biosynthesis , Nitric Oxide Synthase Type II/metabolism , Phosphorylation , RNA, Messenger/biosynthesis , Recombinant Proteins , STAT1 Transcription Factor/metabolism , Signal Transduction/drug effects
13.
Microbiol Immunol ; 55(3): 160-7, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21204955

ABSTRACT

Flavopiridol is a cyclin-dependent kinase inhibitor and inhibits the growth of various cancer cells. The effect of flavopiridol on lipopolysaccharide (LPS)-induced proinflammatory mediator production was examined in RAW 264.7 macrophage-like cells. Flavopiridol significantly reduced the production of tumor necrosis factor-α and, to a lesser extent, nitric oxide in LPS-stimulated cells. Flavopiridol inhibited the activation of nuclear factor-κB and IκB kinase in response to LPS. Flavopiridol also inhibited the activation of a series of mitogen-activated protein kinases, such as p38, stress-activated protein kinase/c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2 in response to LPS. However, flavopiridol did not alter the expression of tumor necrosis factor receptor-associated factor 6, myeloid differentiation factor 88 (MyD88) or CD14/toll-like receptor (TLR) 4. Flavopiridol inhibited nitric oxide production induced by a MyD88-dependent TLR2 ligand, but not a MyD88-independent TLR3 ligand. Further, flavopiridol did not alter the phosphorylation of interferon regulatory factor 3 in the MyD88-independent pathway. Therefore, it was suggested that flavopiridol exclusively inhibited the activation of nuclear factor-κB and mitogen-activated protein kinases in the MyD88-dependent pathway. Flavopiridol might be useful for the prevention of LPS-induced inflammatory response.


Subject(s)
Flavonoids/pharmacology , Gene Expression Regulation, Archaeal/drug effects , Lipopolysaccharides/metabolism , Mitogen-Activated Protein Kinases/metabolism , Myeloid Differentiation Factor 88/metabolism , NF-kappa B/metabolism , Piperidines/pharmacology , Protein Kinase Inhibitors/pharmacology , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Cell Line , Lipopolysaccharide Receptors/metabolism , Macrophages/drug effects , Mice , Nitric Oxide/biosynthesis , Phosphorylation/drug effects , Signal Transduction/drug effects , TNF Receptor-Associated Factor 6/metabolism , Toll-Like Receptors/metabolism
14.
Placenta ; 111: 76-81, 2021 08.
Article in English | MEDLINE | ID: mdl-34175522

ABSTRACT

INTRODUCTION: Recent studies have shown that the endometrium possesses unique microbiomes, including Lactobacillus. However, the roles of these microbes are currently unknown, especially in placentation and the early stage of pregnancy. METHODS: The immortalized human first-trimester trophoblast cell line HTR-8/SVneo was cultured in the presence or absence of Lactobacillus crispatus. Invasive and migrative activities were directly evaluated using an optical microscope and a time-lapse imaging system. Protein levels of the invasion-related protein matrix metalloproteinase (MMP)-1, MMP-2, and MMP-9 were evaluated using ELISA. RESULTS: Matrigel invasion of HTR-8/SVneo cells was significantly increased by L. crispatus, though migration was not affected. The culture supernatant of L. crispatus also promoted invasion. Additionally, levels of the active forms of MMP-1 and MMP-2 in the cell culture medium were upregulated by L. crispatus treatment, but that of MMP-9 was not changed. DISCUSSION: L. crispatus promotes trophoblast invasion with an increase in MMP-1 and MMP-2 activation. Our results might explain why Lactobacillus dominance in the endometrium seems beneficial for implantation. Nevertheless, further research is required to determine whether the promotion of trophoblast invasion by L. cripatus is favorable for successful placentation at the early stage of pregnancy.


Subject(s)
Cell Movement , Lactobacillus crispatus/physiology , Trophoblasts/physiology , Cell Line , Collagen , Drug Combinations , Humans , Laminin , Matrix Metalloproteinases/metabolism , Proteoglycans , Trophoblasts/microbiology
15.
Biosci Microbiota Food Health ; 40(3): 150-155, 2021.
Article in English | MEDLINE | ID: mdl-34285860

ABSTRACT

Sarcopenia causes functional disorders and decreases the quality of life. Thus, it has attracted substantial attention in the aging modern world. Dysbiosis of the intestinal microbiota is associated with sarcopenia; however, it remains unclear whether prebiotics change the microbiota composition and result in the subsequent recovery of muscle atrophy in elderly patients with sarcopenia. This study aimed to assess the effects of prebiotics in super-elderly patients with sarcopenia. We analyzed the effects of 1-kestose on the changes in the intestinal microbiota and body composition using a next-generation sequencer and a multi-frequency bioimpedance analysis device. The Bifidobacterium longum population was significantly increased in the intestine after 1-kestose administration. In addition, in all six patients after 12 weeks of 1-kestose administration, the skeletal muscle mass index was greater, and the body fat percentage was lower. This is the first study to show that administration of a prebiotic increased the population of B. longum in the intestinal microbiota and caused recovery of muscle atrophy in super-elderly patients with sarcopenia.

16.
NPJ Regen Med ; 6(1): 19, 2021 Mar 30.
Article in English | MEDLINE | ID: mdl-33785758

ABSTRACT

Mesenchymal stromal cells (MSCs) are used for ameliorating liver fibrosis and aiding liver regeneration after cirrhosis; Here, we analyzed the therapeutic potential of small extracellular vesicles (sEVs) derived from interferon-γ (IFN-γ) pre-conditioned MSCs (γ-sEVs). γ-sEVs effectively induced anti-inflammatory macrophages with high motility and phagocytic abilities in vitro, while not preventing hepatic stellate cell (HSC; the major source of collagen fiber) activation in vitro. The proteome analysis of MSC-derived sEVs revealed anti-inflammatory macrophage inducible proteins (e.g., annexin-A1, lactotransferrin, and aminopeptidase N) upon IFN-γ stimulation. Furthermore, by enabling CX3CR1+ macrophage accumulation in the damaged area, γ-sEVs ameliorated inflammation and fibrosis in the cirrhosis mouse model more effectively than sEVs. Single cell RNA-Seq analysis revealed diverse effects, such as induction of anti-inflammatory macrophages and regulatory T cells, in the cirrhotic liver after γ-sEV administration. Overall, IFN-γ pre-conditioning altered sEVs resulted in efficient tissue repair indicating a new therapeutic strategy.

17.
Immunology ; 129(1): 97-104, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20050332

ABSTRACT

The regulatory role of tumour necrosis factor-a (TNF-a) on the expression of suppressor of cytokine signalling 3 (SOCS-3) in response to lipopolysaccharide (LPS) was examined using peritoneal macrophages from TNF-a-deficient mice. The LPS-induced SOCS-3 expression was markedly augmented in macrophages from wild-type mice whereas such augmentation was not seen in the cells from TNF-a-deficient mice. However, there was no significant difference in the level of SOCS-3 messenger RNA expression between macrophages from wild-type mice and those from TNF-a-deficient mice. The addition of exogenous TNF-a augmented the LPS-induced SOCS-3 expression in macrophages from TNF-a-deficient mice. The pulse chase analysis suggested augmented degradation of LPS-induced SOCS-3 protein in macrophages from TNF-a-deficient mice. Moreover, MG 132, a 26S proteasome inhibitor, sustained the LPS-induced SOCS-3 expression in those cells. The tyrosine phosphorylation of SOCS-3 was definitely induced in LPS-stimulated macrophages from TNF-a-deficient mice but not wild-type mice. A tyrosine phosphatase inhibitor enhanced the tyrosine phosphorylation of SOCS-3 in wild-type mice and accelerated the degradation. Therefore, it was suggested that TNF-a prevented the degradation of SOCS-3 protein via inhibition of the tyrosine phosphorylation in LPS-stimulated macrophages.


Subject(s)
Macrophages, Peritoneal/metabolism , Protein Tyrosine Phosphatases/metabolism , Recombinant Proteins/pharmacology , Suppressor of Cytokine Signaling Proteins/biosynthesis , Tumor Necrosis Factor-alpha/pharmacology , Animals , Cells, Cultured , Cysteine Proteinase Inhibitors/pharmacology , Leupeptins/pharmacology , Lipopolysaccharides/pharmacology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/pathology , Male , Mice , Mice, Knockout , Phosphorylation , Protein Stability/drug effects , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Suppressor of Cytokine Signaling Proteins/immunology , Tumor Necrosis Factor-alpha/genetics
18.
Immunology ; 131(1): 59-66, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20406300

ABSTRACT

Selective Alzheimer disease indicator-1 (seladin-1) is a broadly expressed oxidoreductase and is related to Alzheimer disease, cholesterol metabolism and carcinogenesis. The effect of lipopolysaccharide (LPS) on the expression of seladin-1 was examined using RAW 264.7 macrophage-like cells and murine peritoneal macrophages. Lipopolysaccharide induced the expression of seladin-1 protein and messenger RNA in those macrophages. The seladin-1 expression was also augmented by a series of Toll-like receptor ligands. The LPS augmented the expression of seladin-1 via reactive oxygen species generation and p38 activation. Seladin-1 inhibited LPS-induced activation of p38 but not nuclear factor-kappaB and inhibited the production of tumour necrosis factor-alpha in response to LPS. Moreover, seladin-1 inhibited LPS-induced osteoclast formation and enhanced LPS-induced alkaline phosphatase activity. Therefore, it was suggested that seladin-1 might be an LPS-responsible gene product and regulate the LPS-induced inflammatory response negatively.


Subject(s)
Lipopolysaccharides/pharmacology , Macrophages/drug effects , Nerve Tissue Proteins/metabolism , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Animals , Cell Line , Lipopolysaccharides/immunology , Macrophages/immunology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/metabolism , Mice , Nerve Tissue Proteins/drug effects , Nerve Tissue Proteins/genetics , Osteoclasts/cytology , Osteoclasts/metabolism , Oxidoreductases Acting on CH-CH Group Donors/drug effects , Oxidoreductases Acting on CH-CH Group Donors/genetics , Polymerase Chain Reaction , Tumor Necrosis Factor-alpha/biosynthesis , Tumor Necrosis Factor-alpha/drug effects
19.
Cell Immunol ; 261(2): 122-7, 2010.
Article in English | MEDLINE | ID: mdl-20036355

ABSTRACT

The effect of a series of toll-like receptor (TLR) ligands on the production of nitric oxide (NO) in mouse B1 cells was examined by using CD5(+) IgM(+) WEHI 231 cells. The stimulation with a series of TLR ligands, which were Pam3Csk4 for TLR1/2, poly I:C for TLR3, lipopolysaccharide (LPS) for TLR4, imiquimod for TLR7 and CpG DNA for TLR9, resulted in enhanced NO production via augmented expression of an inducible type of NO synthase (iNOS). LPS was most potent for the enhancement of NO production, followed by poly I:C and Pam3Csk4. Imiquimod and CpG DNA led to slight NO production. The LPS-induced NO production was dependent on MyD88-dependent pathway consisting of nuclear factor (NF)-kappaB and a series of mitogen-activated protein kinases (MAPKs). Further, it was also dependent on the MyD88-independent pathway consisting of toll-IL-1R domain-containing adaptor-inducing IFN-beta (TRIF) and interferon regulatory factor (IRF)-3. Physiologic peritoneal B1 cells also produced NO via the iNOS expression in response to LPS. The immunological significance of TLR ligands-induced NO production in B1 cells is discussed.


Subject(s)
B-Lymphocytes/immunology , Nitric Oxide/metabolism , Toll-Like Receptors/metabolism , Adaptor Proteins, Vesicular Transport/genetics , Adaptor Proteins, Vesicular Transport/metabolism , Aminoquinolines/metabolism , Animals , CD5 Antigens/metabolism , Cell Line , DNA/metabolism , Female , Imiquimod , Immunoglobulin M/metabolism , Interferon Inducers/metabolism , Ligands , Lipopolysaccharides/metabolism , Mice , Mice, Inbred BALB C , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/metabolism , Nitrites/metabolism , Oligodeoxyribonucleotides/genetics , Oligodeoxyribonucleotides/metabolism , Poly I-C/metabolism , Signal Transduction/physiology
20.
Cell Immunol ; 264(2): 114-8, 2010.
Article in English | MEDLINE | ID: mdl-20557878

ABSTRACT

The involvement of retinoblastoma protein-interacting zinc finger 1 (RIZ1), a tumor suppressor, in lipopolysaccharide (LPS)-induced inflammatory responses was investigated by using RAW 264.7 macrophage-like cells. LPS significantly augmented the expression of RIZ1 and the augmentation was mediated by the activation of nuclear factor (NF)-kappaB and Akt. The silencing of RIZ1 with the siRNA led to the inactivation of NF-kappaB in response to LPS. Moreover, the RIZ1 silencing caused the down-regulation of p53 activation and a p53 pharmacological inhibitor attenuated the RIZ1 expression. LPS-induced tumor necrosis factor-alpha and interleukin-6 production was prevented by RIZ1 siRNA or a p53 pharmacological inhibitor. Therefore, RIZ1 was suggested to augment LPS-induced NF-kappaB activation in collaboration with p53 and enhance the production of proinflammatory cytokines in response to LPS.


Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Interleukin-6/biosynthesis , Macrophages/metabolism , NF-kappa B/metabolism , Transcription Factors/metabolism , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Cell Line , Cloning, Molecular , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/immunology , Inflammation , Interleukin-6/genetics , Interleukin-6/metabolism , Lipopolysaccharides/immunology , Lipopolysaccharides/metabolism , Macrophages/immunology , Macrophages/pathology , Mice , Mutation/genetics , NF-kappa B/genetics , RNA, Small Interfering/genetics , Transcription Factors/genetics , Transcription Factors/immunology , Transcriptional Activation/genetics , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
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