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Shao C, Yang X, Jing Y, Hou X, Huang Y, Zong C, Gao L, Liu W, Jiang J, Ye F, Shi J, Zhao Q, Li R, Zhang X, Wei L. The stemness of hepatocytes is maintained by high levels of lipopolysaccharide via YAP1 activation. Stem Cell Res Ther 2021; 12:342. [PMID: 34112239 PMCID: PMC8193885 DOI: 10.1186/s13287-021-02421-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 05/26/2021] [Indexed: 12/14/2022] Open
Abstract
Background The liver possesses a powerful regeneration ability, which is correlated with the stemness of hepatocytes in the portal vein (PV). However, the mechanism underlying the maintenance of hepatocyte stemness has not been elucidated. Here, we hypothesized that high levels of lipopolysaccharide from the portal vein might maintain the stemness of hepatocytes in the PV area. Methods First, we examined the location of hepatic stem cells and the concentration of lipopolysaccharide (LPS) in the portal vein and inferior vena cava. Then, we assessed the effect of LPS on stemness maintenance in mice by using antibiotics to eliminate LPS and knocking out the LPS receptor, TLR4. In vitro, the effect of LPS on the stemness of hepatocytes was investigated by colony and sphere formation assays and assessment of pluripotent and stem cell marker expression. Furthermore, we studied the mechanism by which LPS regulates the stemness of hepatocytes. Finally, we ligated the portal vein branch to further verify the effect of LPS. Results We found that a high level of LPS from the portal vein was correlated with the location of hepatic stem cells in the PV area, and elimination of LPS by antibiotics inhibited the expression of the stemness marker. LPS promoted colony and sphere formation and induced the upregulation of pluripotent and stem cell markers in AML12 cells. Furthermore, in the reprogramming medium, LPS facilitated the dedifferentiation of mature hepatocytes into hepatic progenitor-like cells, which exhibited a bipotent differentiation capacity in vivo and in vitro. Mechanistically, LPS bound TLR4 to regulate stemness of hepatocytes via the activation of YAP1 signaling, and blockade of YAP1 abolished the LPS-induced cell stemness and upregulation of pluripotent markers. Conclusions Our study implies a correlation between LPS/TLR4/YAP1 signaling and cell stemness, and LPS was shown to be involved in stemness maintenance of hepatocytes in the PV area. LPS might be used to induce the dedifferentiation of mature hepatocytes into progenitor-like cells for repair of liver injury. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02421-7.
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Affiliation(s)
- Changchun Shao
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Xue Yang
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Yingying Jing
- Institute of Translational Medicine, Shanghai University, Shanghai, 200444, China
| | - Xiaojuan Hou
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Yihua Huang
- Department of Pathology, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350108, China
| | - Chen Zong
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Lu Gao
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Wenting Liu
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Jinghua Jiang
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Fei Ye
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Junxia Shi
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Qiudong Zhao
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Rong Li
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China
| | - Xiaoren Zhang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, State Key Laboratory of Respiratory Disease, Guangzhou, 510000, China.
| | - Lixin Wei
- Tumor Immunology and Gene Therapy Center, Third Affiliated Hospital of Second Military Medical University, Shanghai, 200438, China.
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Cyclin-dependent kinase inhibitor roscovitine attenuates liver inflammation and fibrosis by influencing initiating steps of liver injury. Clin Sci (Lond) 2021; 135:925-941. [PMID: 33786590 DOI: 10.1042/cs20201111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 12/16/2022]
Abstract
Liver diseases present a significant public health burden worldwide. Although the mechanisms of liver diseases are complex, it is generally accepted that inflammation is commonly involved in the pathogenesis. Ongoing inflammatory responses exacerbate liver injury, or even result in fibrosis and cirrhosis. Here we report that roscovitine, a cyclin-dependent kinase (CDK) inhibitor, exerts beneficial effects on acute and chronic liver inflammation as well as fibrosis. Animal models of lipopolysaccharide (LPS)/d-galactosamine- and acute or chronic CCl4-induced liver injury showed that roscovitine administration markedly attenuated liver injury, inflammation and histological damage in LPS/d-galactosamine- and CCl4-induced acute liver injury models, which is consistent with the results in vitro. RNA sequencing (RNA-seq) analysis showed that roscovitine treatment repressed the transcription of a broad set of pro-inflammatory genes involved in many aspects of inflammation, including cytokine production and immune cell proliferation and migration, and inhibited the TGF-β signaling pathway and the biological process of tissue remodeling. For further validation, the beneficial effect of roscovitine against inflammation was evaluated in chronic CCl4-challenged mice. The anti-inflammation effect of roscovitine was observed in this model, accompanied with reduced liver fibrosis. The anti-fibrotic mechanism involved inhibition of profibrotic genes and blocking of hepatic stellate cell (HSC) activation. Our data show that roscovitine administration protects against liver diseases through inhibition of macrophage inflammatory actions and HSC activation at the onset of liver injury.
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Thomson AW, Vionnet J, Sanchez-Fueyo A. Understanding, predicting and achieving liver transplant tolerance: from bench to bedside. Nat Rev Gastroenterol Hepatol 2020; 17:719-739. [PMID: 32759983 DOI: 10.1038/s41575-020-0334-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/11/2020] [Indexed: 02/07/2023]
Abstract
In the past 40 years, liver transplantation has evolved from a high-risk procedure to one that offers high success rates for reversal of liver dysfunction and excellent patient and graft survival. The liver is the most tolerogenic of transplanted organs; indeed, immunosuppressive therapy can be completely withdrawn without rejection of the graft in carefully selected, stable long-term liver recipients. However, in other recipients, chronic allograft injury, late graft failure and the adverse effects of anti-rejection therapy remain important obstacles to improved success. The liver has a unique composition of parenchymal and immune cells that regulate innate and adaptive immunity and that can promote antigen-specific tolerance. Although the mechanisms underlying liver transplant tolerance are not well understood, important insights have been gained into how the local microenvironment, hepatic immune cells and specific molecular pathways can promote donor-specific tolerance. These insights provide a basis for the identification of potential clinical biomarkers that might correlate with tolerance or rejection and for the development of novel therapeutic targets. Innovative approaches aimed at promoting immunosuppressive drug minimization or withdrawal include the adoptive transfer of donor-derived or recipient-derived regulatory immune cells to promote liver transplant tolerance. In this Review, we summarize and discuss these developments and their implications for liver transplantation.
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Affiliation(s)
- Angus W Thomson
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. .,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Julien Vionnet
- Institute of Liver Studies, Medical Research Council (MRC) Centre for Transplantation, School of Immunology and Infectious Diseases, King's College London University, King's College Hospital, London, UK.,Transplantation Center, University Hospital of Lausanne, Lausanne, Switzerland.,Service of Gastroenterology and Hepatology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Alberto Sanchez-Fueyo
- Institute of Liver Studies, Medical Research Council (MRC) Centre for Transplantation, School of Immunology and Infectious Diseases, King's College London University, King's College Hospital, London, UK
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4
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Lin M, Long J, Li W, Yang C, Loughran P, O'Doherty R, Billiar TR, Deng M, Scott MJ. Hepatocyte high-mobility group box 1 protects against steatosis and cellular stress during high fat diet feeding. Mol Med 2020; 26:115. [PMID: 33238880 PMCID: PMC7687718 DOI: 10.1186/s10020-020-00227-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis. METHODS Wild type (WT) C57BL/6 and HC-HMGB1-/- mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks. RESULTS As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1-/- mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1-/- mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1-/- mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation. CONCLUSIONS Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.
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Affiliation(s)
- Minjie Lin
- Clinical Skills Training Center, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Jungke Long
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Wenbo Li
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Department of Plastic Surgery, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Chenxuan Yang
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Tsinghua University School of Medicine, Beijing, 100084, China
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Robert O'Doherty
- The Center for Metabolism and Mitochondrial Medicine of University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Meihong Deng
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- University of Pittsburgh, NW607 MUH, 3459 Fifth Ave, Pittsburgh, PA, 15213, USA.
| | - Melanie J Scott
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- University of Pittsburgh, NW653 MUH, 3459 Fifth Ave, Pittsburgh, PA, 15213, USA.
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5
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Seyama M, Yoshida K, Yoshida K, Fujiwara N, Ono K, Eguchi T, Kawai H, Guo J, Weng Y, Haoze Y, Uchibe K, Ikegame M, Sasaki A, Nagatsuka H, Okamoto K, Okamura H, Ozaki K. Outer membrane vesicles of Porphyromonas gingivalis attenuate insulin sensitivity by delivering gingipains to the liver. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165731. [PMID: 32088316 DOI: 10.1016/j.bbadis.2020.165731] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/20/2022]
Abstract
Outer membrane vesicles (OMVs) are nanosized particles derived from the outer membrane of gram-negative bacteria. Oral bacterium Porphyromonas gingivalis (Pg) is known to be a major pathogen of periodontitis that contributes to the progression of periodontal disease by releasing OMVs. The effect of Pg OMVs on systemic diseases is still unknown. To verify whether Pg OMVs affect the progress of diabetes mellitus, we analyzed the cargo proteins of vesicles and evaluated their effect on hepatic glucose metabolism. Here, we show that Pg OMVs were equipped with Pg-derived proteases gingipains and translocated to the liver in mice. In these mice, the hepatic glycogen synthesis in response to insulin was decreased, and thus high blood glucose levels were maintained. Pg OMVs also attenuated the insulin-induced Akt/glycogen synthase kinase-3 β (GSK-3β) signaling in a gingipain-dependent fashion in hepatic HepG2 cells. These results suggest that the delivery of gingipains mediated by Pg OMV elicits changes in glucose metabolisms in the liver and contributes to the progression of diabetes mellitus.
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Affiliation(s)
- Mariko Seyama
- Department of Oral Healthcare Promotion, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kaya Yoshida
- Department of Oral Healthcare Education, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
| | - Kayo Yoshida
- Department of Oral Healthcare Promotion, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Natsumi Fujiwara
- Department of Oral Healthcare Promotion, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kisho Ono
- Department of Dental Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan; Department of Oral and Maxillofacial Surgery and Biopathology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Takanori Eguchi
- Department of Dental Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan; Advanced Research Center for Oral and Craniofacial Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hotaka Kawai
- Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Jiajie Guo
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yao Weng
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Yuan Haoze
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kenta Uchibe
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Mika Ikegame
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Akira Sasaki
- Department of Oral and Maxillofacial Surgery and Biopathology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hitoshi Nagatsuka
- Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kuniaki Okamoto
- Department of Dental Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hirohiko Okamura
- Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Kazumi Ozaki
- Department of Oral Healthcare Promotion, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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6
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Hanslin K, Sjölin J, Skorup P, Wilske F, Frithiof R, Larsson A, Castegren M, Tano E, Lipcsey M. The impact of the systemic inflammatory response on hepatic bacterial elimination in experimental abdominal sepsis. Intensive Care Med Exp 2019; 7:52. [PMID: 31456116 PMCID: PMC6712186 DOI: 10.1186/s40635-019-0266-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/19/2019] [Indexed: 01/29/2023] Open
Abstract
Background Bacterial translocation from the gut has been suggested to induce a systemic inflammatory response syndrome (SIRS) and organ dysfunction. The liver has a pivotal role in eliminating circulating bacteria entering from the gut. We investigated whether pre-existing inflammation affects hepatic bacterial elimination. Methods Fifteen anaesthetised piglets were infused with E. coli in the portal vein for 3 h. The naive group (n = 6) received the bacterial infusion without endotoxin exposure. SIRS (SIRS group, n = 6) was induced by endotoxin infusion 24 h before the bacterial infusion. For effects of anaesthesia, controls (n = 3) received saline instead of endotoxin for 24 h. Bacterial counts and endotoxin levels in the portal and hepatic veins were analysed during bacterial infusion. Results The bacterial killing rate was higher in the naive group compared with the SIRS group (p = 0.001). The ratio of hepatic to portal venous bacterial counts, i.e. the median bacterial influx from the splanchnic circulation, was 0.06 (IQR 0.01–0.11) in the naive group and 0.71 (0.03–1.77) in the SIRS group at 3 h, and a magnitude lower in the naive group during bacteraemia (p = 0.03). Similar results were seen for hepatic endotoxin elimination. Peak log tumour necrosis factor alpha was higher in the naive 4.84 (4.77–4.89) vs. the SIRS group 3.27 (3.26–3.32) mg/L (p < 0.001). Conclusions Our results suggest that hepatic bacterial and endotoxin elimination is impaired in pigs with pre-existing SIRS while the inflammatory response to bacterial infusion is diminished. If similar mechanisms operate in human critical illness, the hepatic elimination of bacteria from the gut could be impaired by SIRS. Electronic supplementary material The online version of this article (10.1186/s40635-019-0266-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katja Hanslin
- Anesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Jan Sjölin
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Paul Skorup
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Frida Wilske
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Robert Frithiof
- Hedenstierna Laboratory, CIRRUS, Anesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Anders Larsson
- Section of Clinical Chemistry, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Markus Castegren
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.,Perioperative Medicine and Intensive Care, Karolinska University Hospital and CLINTEC, Karolinska Institute, Stockholm, Sweden
| | - Eva Tano
- Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Miklos Lipcsey
- Hedenstierna Laboratory, CIRRUS, Anesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
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Khan MGM, Ghosh A, Variya B, Santharam MA, Kandhi R, Ramanathan S, Ilangumaran S. Hepatocyte growth control by SOCS1 and SOCS3. Cytokine 2019; 121:154733. [PMID: 31154249 DOI: 10.1016/j.cyto.2019.154733] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 05/18/2019] [Accepted: 05/21/2019] [Indexed: 02/06/2023]
Abstract
The extraordinary capacity of the liver to regenerate following injury is dependent on coordinated and regulated actions of cytokines and growth factors. Whereas hepatocyte growth factor (HGF) and epidermal growth factor (EGF) are direct mitogens to hepatocytes, inflammatory cytokines such as TNFα and IL-6 also play essential roles in the liver regeneration process. These cytokines and growth factors activate different signaling pathways in a sequential manner to elicit hepatocyte proliferation. The kinetics and magnitude of these hepatocyte-activating stimuli are tightly regulated to ensure restoration of a functional liver mass without causing uncontrolled cell proliferation. Hepatocyte proliferation can become deregulated under conditions of chronic inflammation, leading to accumulation of genetic aberrations and eventual neoplastic transformation. Among the control mechanisms that regulate hepatocyte proliferation, negative feedback inhibition by the 'suppressor of cytokine signaling (SOCS)' family proteins SOCS1 and SOCS3 play crucial roles in attenuating cytokine and growth factor signaling. Loss of SOCS1 or SOCS3 in the mouse liver increases the rate of liver regeneration and renders hepatocytes susceptible to neoplastic transformation. The frequent epigenetic repression of the SOCS1 and SOCS3 genes in hepatocellular carcinoma has stimulated research in understanding the growth regulatory mechanisms of SOCS1 and SOCS3 in hepatocytes. Whereas SOCS3 is implicated in regulating JAK-STAT signaling induced by IL-6 and attenuating EGFR signaling, SOCS1 is crucial for the regulation of HGF signaling. These two proteins also module the functions of certain key proteins that control the cell cycle. In this review, we discuss the current understanding of the functions of SOCS1 and SOCS3 in controlling hepatocyte proliferation, and its implications to liver health and disease.
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Affiliation(s)
- Md Gulam Musawwir Khan
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
| | - Amit Ghosh
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
| | - Bhavesh Variya
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
| | - Madanraj Appiya Santharam
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
| | - Rajani Kandhi
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
| | - Sheela Ramanathan
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada
| | - Subburaj Ilangumaran
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, Québec, Canada.
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Wang YW, Zhang CH, He X. Minor allele of rs1057317 polymorphism in TLR4 is associated with increased risk of Helicobacter pylori -induced gastric cancer. J Cell Biochem 2019; 120:1969-1978. [PMID: 30242897 DOI: 10.1002/jcb.27493] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/25/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND Helicobacter pylori (HP) plays a significant role in the carcinogenesis of gastric cancer (GC), the second leading cause of cancer-related death worldwide. The aim of this study was to investigate the effect of rs1057317 polymorphism on the interaction between microRNA-034a (miR-034a) and toll-like receptor 4 (TLR4), and their involvement in the HP-associated GC. METHODS Computation analyses, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and luciferase assays were performed to identify potential miRNAs involved in the carcinogenesis of HP-induced GC. Subsequently, the effect of miR-34a and recombinant TNFα-interacting protein α (rTip-α) on the expression of TLR4, interleukin (IL)-6, and tumor necrosis factor α (TNF-α) was measured. RESULTS Three hundred and twelve HP-positive GC patients (HP+ GC) and 380 HP-negative GC patients (HP- GC) were enrolled into this study. It was found that, in HP-positive patient, the AA genotype of the rs1057317 polymorphism was closely associated with the risk of GC (95% confidence interval, 1.12 to 2.70; odds ratio, 1.74; P = 0.0129). Furthermore, between the HP+ GC and HP- GC groups, miR-34a was the only miRNA showing a significantly different expression. Subsequently, TLR4 was identified as a target gene of miR-34a. Interestingly, miR-34a evidently reduced the expression of TLR4 3'-untranslated region (3'-UTR) containing the C allele of the rs1057317 polymorphism, but the TLR4 3'-UTR containing the A allele in the rs1057317 was not affected by miR-34a. In addition, the expression of IL-6 and TNF-α was significantly downregulated by miR-34a, but increased by rTip-α. Both miR-34a and rTip-α could enhance the viability of cells, although the effect of rTip-α was stronger. CONCLUSION The data of this study suggested that the rs1057317 polymorphism in the miR-34a binding site of TLR4 may predict the risk of HP-induced GC.
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Affiliation(s)
- Yi-Wei Wang
- General Surgery Department, First Center Clinical College of Tianjin Medical University, Tianjin, China
| | - Cai-Hong Zhang
- Proctology Department, Fourth Xing Yuan Hospital of Yulin, Yulin, China
| | - Xiang He
- Gastroenterology Department, Xi'an XD Group Hospital, Xi'an, China
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9
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Ye F, Winchester D, Stalvey C, Jansen M, Lee A, Khuddus M, Mazza J, Yale S. Proposed mechanisms of relative bradycardia. Med Hypotheses 2018; 119:63-67. [PMID: 30122494 DOI: 10.1016/j.mehy.2018.07.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/18/2018] [Accepted: 07/14/2018] [Indexed: 12/17/2022]
Abstract
Relative bradycardia is the term used to describe the mechanism where there is dissociation between pulse and temperature. This finding is important to recognize since it may provide further insights into the potential underlying causes of disease. There is no known proposed mechanism to explain this phenomenon. We hypothesize that relative bradycardia is the central mechanism reflecting and influenced potentially by the direct pathogenic effect on the sinoatrial node as well as cross-talk between the autonomic nervous system and immune system. Cardiac pacemaker cells may act as a target for inflammatory cytokines leading to alteration in heart rate dynamics or their responsiveness to neurotransmitters during systemic inflammation. These factors account for the important role of how the host response to infectious and non-infectious causes influences the appearance of relative bradycardia. We propose several methods that may be useful to confirm the proposed theoretical framework to further enhance our understanding of this paradoxical phenomenon. This includes measuring, during the episode of relative bradycardia, proinflammatory and anti-inflammatory cytokines, monitoring heart rate variability (HRV), and assessing underlying comorbidities and outcomes in patients with the same disease.
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Affiliation(s)
- Fan Ye
- Graduate Medical Education, University of Central Florida College of Medicine, 6850 Lake Nona Blvd, Orlando, FL 32827, United States
| | - David Winchester
- Department of Cardiology, University of Florida, College of Medicine, Gainesville, FL 32610, United States
| | - Carolyn Stalvey
- Department of General Internal Medicine, University of Florida, College of Medicine, Gainesville, FL 32610, United States
| | - Michael Jansen
- The Cardiac and Vascular Institute, Gainesville, 4645 NW 8th Ave., Gainesville, FL 32605, United States
| | - Arthur Lee
- The Cardiac and Vascular Institute, Gainesville, 4645 NW 8th Ave., Gainesville, FL 32605, United States
| | - Matheen Khuddus
- The Cardiac and Vascular Institute, Gainesville, 4645 NW 8th Ave., Gainesville, FL 32605, United States
| | - Joseph Mazza
- Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449, United States
| | - Steven Yale
- Department of Internal Medicine, University of Central Florida College of Medicine, 6850 Lake Nona Blvd, Orlando, FL 32827, United States.
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10
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Torres-Espín A, Forero J, Fenrich KK, Lucas-Osma AM, Krajacic A, Schmidt E, Vavrek R, Raposo P, Bennett DJ, Popovich PG, Fouad K. Eliciting inflammation enables successful rehabilitative training in chronic spinal cord injury. Brain 2018; 141:1946-1962. [PMID: 29860396 PMCID: PMC6022560 DOI: 10.1093/brain/awy128] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/09/2018] [Accepted: 03/28/2018] [Indexed: 01/24/2023] Open
Abstract
Rehabilitative training is one of the most successful therapies to promote motor recovery after spinal cord injury, especially when applied early after injury. Polytrauma and management of other medical complications in the acute post-injury setting often preclude or complicate early rehabilitation. Therefore, interventions that reopen a window of opportunity for effective motor training after chronic injury would have significant therapeutic value. Here, we tested whether this could be achieved in rats with chronic (8 weeks) dorsolateral quadrant sections of the cervical spinal cord (C4) by inducing mild neuroinflammation. We found that systemic injection of a low dose of lipopolysaccharide improved the efficacy of rehabilitative training on forelimb function, as assessed using a single pellet reaching and grasping task. This enhanced recovery was found to be dependent on the training intensity, where a high-intensity paradigm induced the biggest improvements. Importantly, in contrast to training alone, the combination of systemic lipopolysaccharide and high-intensity training restored original function (reparative plasticity) rather than enhancing new motor strategies (compensatory plasticity). Accordingly, electrophysiological and tract-tracing studies demonstrated a recovery in the cortical drive to the affected forelimb muscles and a restructuration of the corticospinal innervation of the cervical spinal cord. Thus, we propose that techniques that can elicit mild neuroinflammation may be used to enhance the efficacy of rehabilitative training after chronic spinal cord injury.
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Affiliation(s)
- Abel Torres-Espín
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Juan Forero
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Keith K Fenrich
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Ana M Lucas-Osma
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Aleksandra Krajacic
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Emma Schmidt
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Romana Vavrek
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Pamela Raposo
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - David J Bennett
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
| | - Phillip G Popovich
- Center for Brain and Spinal Cord Repair, Department of Neuroscience, 460 W. 12th Ave., 694 Biomedical Research Tower, Ohio State University; Columbus, Ohio, USA
| | - Karim Fouad
- Faculty of Rehabilitation Medicine, University of Alberta; Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta; Edmonton, Alberta, Canada
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11
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Li M, Song K, Huang X, Fu S, Zeng Q. GDF‑15 prevents LPS and D‑galactosamine‑induced inflammation and acute liver injury in mice. Int J Mol Med 2018; 42:1756-1764. [PMID: 29956733 DOI: 10.3892/ijmm.2018.3747] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 06/22/2018] [Indexed: 11/06/2022] Open
Abstract
Growth differentiation factor‑15 (GDF‑15) is a transforming growth factor (TGF)‑β superfamily member with a poorly characterized biological activity, speculated to be implicated in several diseases. The present study aimed to determine whether GDF‑15 participates in sepsis‑induced acute liver injury in mice. Lipopolysaccharide (LPS) and D‑galactosamine (D‑GalN) were administered to mice to induce acute liver injury. Survival of mice, histological changes in liver tissue, and levels of inflammatory biomarkers in serum and liver tissue were evaluated following treatment with GDF‑15. The underlying mechanism was investigated by western blotting, ELISA, flow cytometry, and reverse transcription‑quantitative polymerase chain reaction using Kupffer cells. The results demonstrated that GDF‑15 prevented LPS/D‑GalN‑induced death, increase in inflammatory cell infiltration and serum alanine aminotransferase and aspartate aminotransferase activities. In addition, GDF‑15 treatment reduced the production of hepatic malondialdehyde and myeloperoxidase, and attenuated the increase of interleukin (IL)‑6, tumor necrosis factor (TNF)‑α, and IL‑1β expression in serum and liver tissue, accompanied by inducible nitric oxide synthase (iNOS) inactivation in the liver. Similar changes in the expression of inflammatory cytokines, IL‑6, TNF‑α and IL‑1β, and iNOS activation were observed in the Kupffer cells. Further mechanistic experiments revealed that GDF‑15 effectively protected against LPS‑induced nuclear factor (NF)‑κB pathway activation by regulating TGFβ‑activated kinase 1 (TAK1) phosphorylation in Kupffer cells. In conclusion, GDF‑15 reduced the activation of pro‑inflammatory factors, and prevented LPS‑induced liver injury, most likely by disrupting TAK1 phosphorylation, and consequently inhibiting the activation of the NF‑κB pathway in the liver.
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Affiliation(s)
- Min Li
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Kui Song
- Department of Hematology, The First Affiliated Hospital of Jishou University, Jishou, Hunan 416000, P.R. China
| | - Xiaowen Huang
- Department of Pediatrics, Boai Hospital of Zhongshan City, Zhongshan, Guangdong 528400, P.R. China
| | - Simao Fu
- Department of Pediatrics, Boai Hospital of Zhongshan City, Zhongshan, Guangdong 528400, P.R. China
| | - Qiyi Zeng
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
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12
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Fetal and Maternal Innate Immunity Receptors Have Opposing Effects on the Severity of Experimental Malaria in Pregnancy: Beneficial Roles for Fetus-Derived Toll-Like Receptor 4 and Type I Interferon Receptor 1. Infect Immun 2018; 86:IAI.00708-17. [PMID: 29440369 PMCID: PMC5913849 DOI: 10.1128/iai.00708-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/07/2018] [Indexed: 12/13/2022] Open
Abstract
Malaria in pregnancy (MiP) is a distinctive clinical form of Plasmodium infection and is a cause of placental insufficiency leading to poor pregnancy outcomes. Maternal innate immunity responses play a decisive role in the development of placental inflammation, but the action of fetus-derived factors in MiP outcomes has been overlooked. We investigated the role of the Tlr4 and Ifnar1 genes, taking advantage of heterogenic mating strategies to dissect the effects mediated by maternally and fetally derived Toll-like receptor 4 (TLR4) or type I interferon receptor 1 (IFNAR1). Using a mouse infection system displaying severe MiP outcomes, we found that the expressions of TLR4 and IFNAR1 in the maternal compartment take part in deleterious MiP outcomes, but their fetal counterparts patently counteract these effects. We uncovered that fetal TLR4 contributes to the in vitro uptake of infected erythrocytes by trophoblasts and to the innate immune response in the placenta, offering robust protection of fetus viability, but had no sensible impact on the placental parasite burden. In contrast, we observed that the expression of IFNAR1 in the fetal compartment was associated with a reduced placental parasite burden but had little beneficial effect on fetus outcomes. Furthermore, the downregulation of Ifnar1 expression in infected placentas and in trophoblasts exposed to infected erythrocytes indicated that the interferon-IFNAR1 pathway is involved in the trophoblast response to infection. This work unravels that maternal and fetal counterparts of innate immune pathways drive opposing responses in murine placental malaria and implicates the activation of innate receptors in fetal trophoblast cells in the control of placental infection and in the protection of the fetus.
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13
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Yang D, Zheng X, Wang N, Fan S, Yang Y, Lu Y, Chen Q, Liu X, Zheng J. Kukoamine B promotes TLR4-independent lipopolysaccharide uptake in murine hepatocytes. Oncotarget 2018; 7:57498-57513. [PMID: 27542278 PMCID: PMC5295368 DOI: 10.18632/oncotarget.11292] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 08/11/2016] [Indexed: 12/30/2022] Open
Abstract
Free bacterial lipopolysaccharide (LPS) is generally removed from the bloodstream through hepatic uptake via TLR4, the LPS pattern recognition receptor, but mechanisms for internalization and clearance of conjugated LPS are less clear. Kukoamine B (KB) is a novel cationic alkaloid that interferes with LPS binding to TLR4. In this study, KB accelerated blood clearance of LPS. KB also enhanced LPS distribution in the hepatic tissues of C57 BL/6 mice, along with LPS uptake in primary hepatocytes and HepG2 cells. By contrast, KB inhibited LPS internalization in Kupffer and RAW 264.7 cells. Loss of TLR4 did not affect LPS uptake into KB-treated hepatocytes. We also detected selective upregulation of the asialoglycoprotein receptor (ASGPR) upon KB treatment, and ASGPR colocalized with KB in cultured hepatocytes. Molecular docking showed that KB bound to ASGPR in a manner similar to GalNAc, a known ASGPR agonist. GalNAc dose-dependently reduced KB internalization, suggesting it competes with KB for ASGPR binding, and ASGPR knockdown also impaired LPS uptake into hepatocytes. Finally, while KB enhanced LPS uptake, it was protective against LPS-induced inflammation and hepatocyte injury. Our study provides a new mechanism for conjugated LPS hepatic uptake induced by the LPS neutralizer KB and mediated by membrane ASGPR binding.
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Affiliation(s)
- Dong Yang
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xinchuan Zheng
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Ning Wang
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Shijun Fan
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yongjun Yang
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yongling Lu
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Qian Chen
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xin Liu
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jiang Zheng
- Medical Research Center, Southwest Hospital, Third Military Medical University, Chongqing, China
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14
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Duncan SA, Baganizi DR, Sahu R, Singh SR, Dennis VA. SOCS Proteins as Regulators of Inflammatory Responses Induced by Bacterial Infections: A Review. Front Microbiol 2017; 8:2431. [PMID: 29312162 PMCID: PMC5733031 DOI: 10.3389/fmicb.2017.02431] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 11/23/2017] [Indexed: 12/31/2022] Open
Abstract
Severe bacterial infections can lead to both acute and chronic inflammatory conditions. Innate immunity is the first defense mechanism employed against invading bacterial pathogens through the recognition of conserved molecular patterns on bacteria by pattern recognition receptors (PRRs), especially the toll-like receptors (TLRs). TLRs recognize distinct pathogen-associated molecular patterns (PAMPs) that play a critical role in innate immune responses by inducing the expression of several inflammatory genes. Thus, activation of immune cells is regulated by cytokines that use the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway and microbial recognition by TLRs. This system is tightly controlled by various endogenous molecules to allow for an appropriately regulated and safe host immune response to infections. Suppressor of cytokine signaling (SOCS) family of proteins is one of the central regulators of microbial pathogen-induced signaling of cytokines, principally through the inhibition of the activation of JAK/STAT signaling cascades. This review provides recent knowledge regarding the role of SOCS proteins during bacterial infections, with an emphasis on the mechanisms involved in their induction and regulation of antibacterial immune responses. Furthermore, the implication of SOCS proteins in diverse processes of bacteria to escape host defenses and in the outcome of bacterial infections are discussed, as well as the possibilities offered by these proteins for future targeted antimicrobial therapies.
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Affiliation(s)
- Skyla A Duncan
- Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, United States
| | - Dieudonné R Baganizi
- Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, United States
| | - Rajnish Sahu
- Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, United States
| | - Shree R Singh
- Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, United States
| | - Vida A Dennis
- Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL, United States
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15
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Yu J, Zhang W, Qian H, Tang H, Lin W, Lu B. SOCS1 regulates hepatic regenerative response and provides prognostic makers for acute obstructive cholangitis. Sci Rep 2017; 7:9482. [PMID: 28842621 PMCID: PMC5573403 DOI: 10.1038/s41598-017-09865-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 07/31/2017] [Indexed: 12/31/2022] Open
Abstract
Acute obstructive cholangitis (AOC) is a common and severe infectious diseases that occurs in an obstructed biliary system. The suppressors of cytokine signaling (SOCS) family include well-known negative regulators of cytokine receptor signaling. However, few studies have been conducted to determine their function in AOC. In this study, we showed that SOCS1 expression aberrantly changed and was associated with AOC prognosis in rat models. Decreased SOCS1 expression enhances regenerative response after biliary drainage (BD) resulting from AOC by upregulating hepatocyte growth factor (HGF) signaling. To detect SOCS1 expression in the liver less invasively and to predict the prognosis for AOC after BD, miR-221 and miR-222 were investigated. Ectopic SOCS1 expression indirectly decreases miR-221/222 expression through Met in vitro. An inverse correlation between SOCS1 expression and miR-221/222 expression in liver tissue or in serum was verified in rats. Serum from AOC patients showed that lower expression of circulating miR-221/222 after endoscopic nasobiliary drainage was associated with delayed restoration of liver function. Our results showed that SOCS1 regulates hepatic regenerative response, and indirectly detecting downstream molecules, such as miR-221/222, may provide prognostic makers for AOC.
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Affiliation(s)
- Jianhua Yu
- Department of Hepatobiliary Surgery, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China
| | - Weiguang Zhang
- Department of Molecular Medicine and Clinical Laboratory, Shaoxing Second Hospital, Shaoxing, China
| | - Hongwei Qian
- Department of Hepatobiliary Surgery, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China
| | - Haijun Tang
- Department of Hepatobiliary Surgery, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China
| | - Weiguo Lin
- Department of Hepatobiliary Surgery, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China
| | - Baochun Lu
- Department of Hepatobiliary Surgery, Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, China.
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16
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Bala S, Csak T, Kodys K, Catalano D, Ambade A, Furi I, Lowe P, Cho Y, Iracheta-Vellve A, Szabo G. Alcohol-induced miR-155 and HDAC11 inhibit negative regulators of the TLR4 pathway and lead to increased LPS responsiveness of Kupffer cells in alcoholic liver disease. J Leukoc Biol 2017; 102:487-498. [PMID: 28584078 PMCID: PMC6608073 DOI: 10.1189/jlb.3a0716-310r] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 04/11/2017] [Accepted: 05/04/2017] [Indexed: 12/13/2022] Open
Abstract
Inflammation promotes the progression of alcoholic liver disease. Alcohol sensitizes KCs to gut-derived endotoxin (LPS); however, signaling pathways that perpetuate inflammation in alcoholic liver disease are only partially understood. We found that chronic alcohol feeding in mice induced miR-155, an inflammatory miRNA in isolated KCs. We hypothesized that miR-155 might increase the responsiveness of KCs to LPS via targeting the negative regulators of LPS signaling. Our results revealed that KCs that were isolated from alcohol-fed mice showed a decrease in IRAK-M, SHIP1, and PU.1, and an increase in TNF-α levels. This was specific to KCs, as no significant differences were observed in these genes in hepatocytes. We found a causal effect of miR-155 deficiency on LPS responsiveness, as KCs that were isolated from miR-155 KO mice showed a greater induction of IRAK-M, SHIP1, and suppressor of cytokine signaling 1 after LPS treatment. C/EBPβ, a validated miR-155 target, stimulates IL-10 transcription. We found a higher induction of C/EBPβ and IL-10 in KCs that were isolated from miR-155 KO mice after LPS treatment. Gain- and loss-of-function studies affirmed that alcohol-induced miR-155 directly regulates IRAK-M, SHIP1, suppressor of cytokine signaling 1, and C/EBPβ, as miR-155 inhibition increased and miR-155 overexpression decreased these genes in LPS or alcohol-pretreated wild-type KCs. HDAC11, a regulator of IL-10, was significantly increased and IL-10 was decreased in KCs that were isolated from alcohol-fed mice. Functionally, knockdown of HDAC11 with small interfering RNA resulted in an IL-10 increase in LPS or alcohol-pretreated Mϕ. We found that acetaldehyde and NF-κB pathways regulate HDAC11 levels. Collectively, our results indicate that the alcohol-induced responsiveness of KCs to LPS, in part, is governed by miR-155 and HDAC11.
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Affiliation(s)
- Shashi Bala
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Timea Csak
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Karen Kodys
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Donna Catalano
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Aditya Ambade
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Istvan Furi
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Patrick Lowe
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Yeonhee Cho
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Arvin Iracheta-Vellve
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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17
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Wubing C, Yuqiong D, Lianyin G, Niancong C, Qiuyun Z, Xiuwen F, Jiajia L, Rongbing W. Lipopolysaccharide/Toll-like receptor 4 signaling pathway involved Qingdu decoction treating severe liver injury merging with endotoxemia. J TRADIT CHIN MED 2017. [DOI: 10.1016/s0254-6272(17)30073-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Li L, Cao Y, Xie Z, Zhang Y. A High-Concentrate Diet Induced Milk Fat Decline via Glucagon-Mediated Activation of AMP-Activated Protein Kinase in Dairy Cows. Sci Rep 2017; 7:44217. [PMID: 28287130 PMCID: PMC5347023 DOI: 10.1038/srep44217] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 02/06/2017] [Indexed: 12/17/2022] Open
Abstract
Dairy cows are often fed a high-concentrate (HC) diet to meet lactation demands; however, long-term concentrate feeding is unhealthy and decreases milk fat. Therefore, we investigated the effects of liver lipid metabolism on milk fat synthesis. Ten lactating Holstein cows were assigned randomly into HC and LC (low-concentrate) diet groups. After 20 weeks of feeding, milk fat declined, and lipopolysaccharide levels in the jugular, portal, and hepatic veins increased in the HC group. Liver consumption and release of nonesterified fatty acid (NEFA) into the bloodstream also decreased. AMP-activated protein kinase alpha (AMPKα) was up-regulated significantly in the livers of the HC-fed cows. The HC diet also up-regulated the expression of the transcription factor peroxisome proliferator-activated receptor α (PPARα) and its downstream targets involved in fatty acid oxidation, including carnitine palmitoyltransferase-1,2 (CPT-1, CPT-2), liver-fatty acid-binding protein (L-FABP), and acyl-CoA oxidase (ACO). The HC diet increased blood glucagon (GC) levels, and liver glucagon receptor (GCGR) expression was elevated. Cumulatively, a long-term HC diet decreased plasma concentrations of NEFA via the GC/GCGR-AMPK-PPARα signalling pathway and reduced their synthesis in the liver. The decreased NEFA concentration in the blood during HC feeding may explain the decline in the milk fat of lactating cows.
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Affiliation(s)
- Lin Li
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Yang Cao
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Zhenglu Xie
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, China
| | - Yuanshu Zhang
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, China
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19
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Abstract
Sepsis and septic shock are characterized by life-threatening organ dysfunction caused by a dysregulated host response to infection. The liver has a central role during sepsis, and is essential to the regulation of immune defence during systemic infections by mechanisms such as bacterial clearance, acute-phase protein or cytokine production and metabolic adaptation to inflammation. However, the liver is also a target for sepsis-related injury, including hypoxic hepatitis due to ischaemia and shock, cholestasis due to altered bile metabolism, hepatocellular injury due to drug toxicity or overwhelming inflammation, as well as distinct pathologies such as secondary sclerosing cholangitis in critically ill patients. Hence, hepatic dysfunction substantially impairs the prognosis of sepsis and serves as a powerful independent predictor of mortality in the intensive care unit. Sepsis is particularly problematic in patients with liver cirrhosis (who experience increased bacterial translocation from the gut and impaired microbial defence) as it can trigger acute-on-chronic liver failure - a syndrome with high short-term mortality. Here, we review the importance of the liver as a guardian, modifier and target of sepsis, the factors that contribute to sepsis in patients with liver cirrhosis and new therapeutic strategies.
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20
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Gram Negative Bacterial Inflammation Ameliorated by the Plasma Protein Beta 2-Glycoprotein I. Sci Rep 2016; 6:33656. [PMID: 27670000 PMCID: PMC5037396 DOI: 10.1038/srep33656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/31/2016] [Indexed: 01/12/2023] Open
Abstract
Lipopolysaccharide (LPS) is a major component of the outer wall of gram negative bacteria. In high doses LPS contributes to the inflammation in gram negative sepsis, and in low doses contributes to the low grade inflammation characteristic of the metabolic syndrome. We wanted to assess the role of beta2-glycoprotein I (β2GPI) a highly conserved plasma protein and its different biochemical forms in a mouse model of LPS systemic inflammation. Normal and β2GPI deficient mice were administered LPS through their veins and assessed for a range of inflammation markers in their blood and liver. Different biochemical forms of β2GPI were measured in normal mice given either saline or LPS. We show that β2GPI has a significant role in inhibiting LPS induced inflammation. In this study we provide some evidence that β2GPI serves a protective role in a mouse model of LPS inflammation. This resolves the controversy of previous studies which used LPS and β2GPI in test tube based models of LPS induced activation of white cells. We also highlight the potential relevance of a newly discovered biochemical form of β2GPI in LPS mediated inflammation and we speculate that this form has a protective role against LPS induced pathology.
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21
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Topchiy E, Cirstea M, Kong HJ, Boyd JH, Wang Y, Russell JA, Walley KR. Lipopolysaccharide Is Cleared from the Circulation by Hepatocytes via the Low Density Lipoprotein Receptor. PLoS One 2016; 11:e0155030. [PMID: 27171436 PMCID: PMC4865154 DOI: 10.1371/journal.pone.0155030] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 04/02/2016] [Indexed: 01/12/2023] Open
Abstract
Sepsis is the leading cause of death in critically ill patients. While decreased Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) function improves clinical outcomes in murine and human sepsis, the mechanisms involved have not been fully elucidated. We tested the hypothesis that lipopolysaccharide (LPS), the major Gram-negative bacteria endotoxin, is cleared from the circulation by hepatocyte Low Density Lipoprotein Receptors (LDLR)—receptors downregulated by PCSK9. We directly visualized LPS uptake and found that LPS is rapidly taken up by hepatocytes into the cell periphery. Over the course of 4 hours LPS is transported towards the cell center. We next found that clearance of injected LPS from the blood was reduced substantially in Ldlr knockout (Ldlr-/-) mice compared to wild type controls and, simultaneously, hepatic uptake of LPS was also reduced in Ldlr-/- mice. Specifically examining the role of hepatocytes, we further found that primary hepatocytes isolated from Ldlr-/- mice had greatly decreased LPS uptake. In the HepG2 immortalized human hepatocyte cell line, LDLR silencing similarly resulted in decreased LPS uptake. PCSK9 treatment reduces LDLR density on hepatocytes and, therefore, was another independent strategy to test our hypothesis. Incubation with PCSK9 reduced LPS uptake by hepatocytes. Taken together, these findings demonstrate that hepatocytes clear LPS from the circulation via the LDLR and PCSK9 regulates LPS clearance from the circulation during sepsis by downregulation of hepatic LDLR.
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Affiliation(s)
- Elena Topchiy
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - Mihai Cirstea
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - HyeJin Julia Kong
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - John H Boyd
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - Yingjin Wang
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - James A Russell
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - Keith R Walley
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
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22
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Baranova IN, Souza ACP, Bocharov AV, Vishnyakova TG, Hu X, Vaisman BL, Amar MJ, Chen Z, Kost Y, Remaley AT, Patterson AP, Yuen PST, Star RA, Eggerman TL. Human SR-BI and SR-BII Potentiate Lipopolysaccharide-Induced Inflammation and Acute Liver and Kidney Injury in Mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2016; 196:3135-47. [PMID: 26936883 PMCID: PMC4856165 DOI: 10.4049/jimmunol.1501709] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 01/24/2016] [Indexed: 12/18/2022]
Abstract
The class B scavenger receptors BI (SR-BI) and BII (SR-BII) are high-density lipoprotein receptors that recognize various pathogens, including bacteria and their products. It has been reported that SR-BI/II null mice are more sensitive than normal mice to endotoxin-induced inflammation and sepsis. Because the SR-BI/II knockout model demonstrates multiple immune and metabolic disorders, we investigated the role of each receptor in the LPS-induced inflammatory response and tissue damage using transgenic mice with pLiv-11-directed expression of human SR-BI (hSR-BI) or human SR-BII (hSR-BII). At 6 h after i.p. LPS injection, transgenic hSR-BI and hSR-BII mice demonstrated markedly higher serum levels of proinflammatory cytokines and 2- to 3-fold increased expression levels of inflammatory mediators in the liver and kidney, compared with wild-type (WT) mice. LPS-stimulated inducible NO synthase expression was 3- to 6-fold higher in the liver and kidney of both transgenic strains, although serum NO levels were similar in all mice. Despite the lower high-density lipoprotein plasma levels, both transgenic strains responded to LPS by a 5-fold increase of plasma corticosterone levels, which were only moderately lower than in WT animals. LPS treatment resulted in MAPK activation in tissues of all mice; however, the strongest response was detected for hepatic extracellular signal-regulated protein kinase 1 and 2 and kidney JNK of both transgenic mice. Histological examination of hepatic and renal tissue from LPS-challenged mice revealed more injury in hSR-BII, but not hSR-BI, transgenic mice versus WT controls. Our findings demonstrate that hSR-BII, and to a lesser extent hSR-BI, significantly increase LPS-induced inflammation and contribute to LPS-induced tissue injury in the liver and kidney, two major organs susceptible to LPS toxicity.
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Affiliation(s)
- Irina N Baranova
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892
| | - Ana C P Souza
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Alexander V Bocharov
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892;
| | - Tatyana G Vishnyakova
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892
| | - Xuzhen Hu
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Boris L Vaisman
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Marcelo J Amar
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Zhigang Chen
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892
| | - Yana Kost
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892
| | - Alan T Remaley
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Amy P Patterson
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892; National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Peter S T Yuen
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Robert A Star
- Renal Diagnostics and Therapeutics Unit, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Thomas L Eggerman
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892; Division of Diabetes, Endocrinology, and Metabolic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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23
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Patra S, Muthuraman MS, Meenu M, Priya P, Pemaiah B. Anti-inflammatory effects of royal poinciana through inhibition of toll-like receptor 4 signaling pathway. Int Immunopharmacol 2016; 34:199-211. [PMID: 26971223 DOI: 10.1016/j.intimp.2016.02.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/08/2016] [Accepted: 02/22/2016] [Indexed: 02/06/2023]
Abstract
Inflammation is part of the non-specific immune response that occurs in reaction to any type of bodily injury. In some disorders the inflammatory process, which under normal conditions is self-limiting, becomes continuous and chronic inflammatory diseases develop subsequently including cardiovascular diseases, diabetes, cancer etc. Barks of Delonix regia is used traditionally in the treatment of inflammatory diseases. Therefore, in this study we evaluated the therapeutic potential of D. regia ethanol extract and its active constituent β-Elemene with special interest in inflammation model using standard in vivo anti-inflammatory models: Carrageenan-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To explicate the mechanism of action for the possible anti-inflammatory activity, we determined the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2), and pro-inflammatory cytokines (TNF-a, IL-1b, IL-6, and IL-12). Additionally, we determined the toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 (MyD88), by mRNA expression in drug treated LPS-induced murine macrophage model. To explore the mechanism of anti-inflammatory activity, we evaluated expression of c-Jun N-terminal kinases (JNK), nuclear factor kappa-B cells (NF-kB), and NF-kB inhibitor alpha (IK-Ba). Furthermore, we determined the acute and sub-acute toxicity of D. regia extract in BALB/c mice. This study established a significant anti-inflammatory activity of D. regia extract and β-Elemene along with the inhibition of TNF-a, IL-1b, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-kBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the D. regia extract and β-Elemene can efficiently inhibit inflammation.
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Affiliation(s)
- Satyajit Patra
- American International Medical University, Bosejour Road, Gros Islet, Saint Lucia
| | | | - M Meenu
- Department of Biotechnology, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India
| | - Padma Priya
- Department of Biotechnology, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India
| | - Brindha Pemaiah
- Centre for Advanced Research in Indian System of Medicine, SASTRA University, Thanjavur, Tamil Nadu, India
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24
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Grakoui A, Crispe IN. Presentation of hepatocellular antigens. Cell Mol Immunol 2016; 13:293-300. [PMID: 26924525 PMCID: PMC4856799 DOI: 10.1038/cmi.2015.109] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/24/2015] [Accepted: 11/25/2015] [Indexed: 12/31/2022] Open
Abstract
The liver is an organ in which antigen-specific T-cell responses manifest a bias toward immune tolerance. This is clearly seen in the rejection of allogeneic liver transplants, and multiple other phenomena suggest that this effect is more general. These include tolerance toward antigens introduced via the portal vein, immune failure to several hepatotropic viruses, the lack of natural liver-stage immunity to malaria parasites, and the frequent metastasis of cancers to the liver. Here we review the mechanisms by which T cells engage with hepatocellular antigens, the context in which such encounters occur, and the mechanisms that act to suppress a full T-cell response. While many mechanisms play a role, we will argue that two important processes are the constraints on the cross-presentation of hepatocellular antigens, and the induction of negative feedback inhibition driven by interferons. The constant exposure of the liver to microbial products from the intestine may drive innate immunity, rendering the local environment unfavorable for specific T-cell responses through this mechanism. Nevertheless, tolerance toward hepatocellular antigens is not monolithic and under specific circumstances allows both effective immunity and immunopathology.
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Affiliation(s)
- Arash Grakoui
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine and Yerkes National Primate Research Center, Atlanta, GA, USA
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25
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Wallace RJ, Gropp J, Dierick N, Costa LG, Martelli G, Brantom PG, Bampidis V, Renshaw DW, Leng L. Risks associated with endotoxins in feed additives produced by fermentation. Environ Health 2016; 15:5. [PMID: 26768246 PMCID: PMC4714429 DOI: 10.1186/s12940-016-0087-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/10/2016] [Indexed: 05/27/2023]
Abstract
Increasingly, feed additives for livestock, such as amino acids and vitamins, are being produced by Gram-negative bacteria, particularly Escherichia coli. The potential therefore exists for animals, consumers and workers to be exposed to possibly harmful amounts of endotoxin from these products. The aim of this review was to assess the extent of the risk from endotoxins in feed additives and to calculate how such risk can be assessed from the properties of the additive. Livestock are frequently exposed to a relatively high content of endotoxin in the diet: no additional hazard to livestock would be anticipated if the endotoxin concentration of the feed additive falls in the same range as feedstuffs. Consumer exposure will be unaffected by the consumption of food derived from animals receiving endotoxin-containing feed, because the small concentrations of endotoxin absorbed do not accumulate in edible tissues. In contrast, workers processing a dusty additive may be exposed to hazardous amounts of endotoxin even if the endotoxin concentration of the product is low. A calculation method is proposed to compare the potential risk to the worker, based on the dusting potential, the endotoxin concentration and technical guidance of the European Food Safety Authority, with national exposure limits.
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Affiliation(s)
- R John Wallace
- Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, AB21 9SB, UK.
| | | | - Noël Dierick
- Department of Animal Production, Ghent University, Ghent, Belgium.
| | - Lucio G Costa
- Department of Neuroscience, University of Parma, Parma, Italy.
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA.
| | - Giovanna Martelli
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
| | | | - Vasileios Bampidis
- Division of Animal Production, Department of Agricultural Technology, School of Agricultural Technology, Food Technology and Nutrition, Alexander Technological Educational Institute (ATEITHE), 57400, Thessaloniki, Greece.
| | | | - Lubomir Leng
- Institute of Animal Physiology, Slovak Academy of Sciences, Kosice, Slovakia.
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26
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Liu X, Qin Y, Dai A, Zhang Y, Xue H, Ni H, Han L, Zhu L, Yuan D, Tao T, Cao M. SMAD4 is Involved in the Development of Endotoxin Tolerance in Microglia. Cell Mol Neurobiol 2016; 36:777-88. [PMID: 26758028 DOI: 10.1007/s10571-015-0260-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/25/2015] [Indexed: 12/11/2022]
Abstract
Initial exposure of macrophages to LPS induces hyporesponsiveness to a second challenge with LPS, a phenomenon termed LPS tolerance. Smad4 plays important roles in the induction of LPS tolerance. However, the function of Smad4 in microglia remains unknown. Here we show that expression of Smad4 was highly up-regulated in LPS-tolerized mouse cerebral cortex. Smad4 was mostly colocalized with microglia, rarely with neurons. Using a microglia cell line, BV2, we find that LPS activates endogenous Smad4, inducing its migration into the nucleus and increasing its expression. Smad4 significantly suppressed TLR-triggered production of proinflammatory cytokines (IL-6), increased anti-inflammatory cytokine in LPS-tolerized microglia. Moreover, IL-6 concentrations in culture supernatants after second LPS challenge are higher in SMAD4 small interfering RNA (siRNA) BV2 cells than control siRNA BV2 cells, indicating failure to induce tolerance in absence of Smad4 signaling. In our study, we conclude that both in vivo and in vitro, Smad4 signaling is required for maximal induction of endotoxin tolerance.
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Affiliation(s)
- Xiaorong Liu
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Yongwei Qin
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina.,Department of Pathogen Biology, Medical College of Nantong University, Nantong, 226001, China
| | - Aihua Dai
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Yu Zhang
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Huaqing Xue
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina
| | - Haidan Ni
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Lijian Han
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Liang Zhu
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Debin Yuan
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina
| | - Tao Tao
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina.
| | - Maohong Cao
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China.
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27
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Deng M, Ma T, Yan Z, Zettel KR, Scott MJ, Liao H, Frank A, Morelli AE, Sodhi CP, Hackam DJ, Billiar TR. Toll-like Receptor 4 Signaling on Dendritic Cells Suppresses Polymorphonuclear Leukocyte CXCR2 Expression and Trafficking via Interleukin 10 During Intra-abdominal Sepsis. J Infect Dis 2015; 213:1280-8. [PMID: 26603204 DOI: 10.1093/infdis/jiv562] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 11/09/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Toll-like receptor 4 (TLR4) is a critical receptor involved in the sensing of gram-negative bacterial infection. However, the roles of TLR4 in sepsis are cell-type specific. Dendritic cells (DCs) are known to play a central role in microbial detection, alerting the immune system to the presence of infection and coordinating adaptive immune response. The goal of this study was to investigate the impact of DC-specific TLR4 signaling on host defense against intra-abdominal polymicrobial sepsis. METHODS C57BL/6, global Tlr4 knockout, cell-specific knockout control, and CD11c-specific Tlr4(-/-) mice underwent cecal ligation and puncture (CLP). RESULTS Specific deletion of TLR4 on DCs in mice improved survival and enhanced bacterial clearance. Deletion of TLR4 on DCs was associated with lower levels of circulating interleukin 10 (IL-10), higher polymorphonuclear leukocyte (PMN) accumulation in the peritoneal cavity, and higher expression of chemokine (C-X-C motif) receptor 2 (CXCR2) on PMNs after CLP. In vitro studies of DC and neutrophil cocultures confirmed that TLR4-dependent secretion of IL-10 from DCs regulated neutrophil CXCR2 expression. CONCLUSIONS Our data shed light on a previously unrecognized role for TLR4 signaling on DCs in driving IL-10 secretion during sepsis and, through this pathway, regulates PMN recruitment via suppression of CXCR2 expression.
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Affiliation(s)
- Meihong Deng
- Department of Surgery, University of Pittsburgh, Pennsylvania
| | - Tao Ma
- Department of General Surgery, Tianjin Medical University General Hospital
| | - Zhengzheng Yan
- Department of Pathophysiology, Southern Medical University, Guangzhou, China
| | - Kent R Zettel
- Department of Surgery, University of Pittsburgh, Pennsylvania
| | - Melanie J Scott
- Department of Surgery, University of Pittsburgh, Pennsylvania
| | - Hong Liao
- Department of Surgery, University of Pittsburgh, Pennsylvania
| | - Alicia Frank
- Department of Surgery, University of Pittsburgh, Pennsylvania
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28
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Tang J, Li L, Li CM, Wu J, Sun Y, Wang GL. Upregulation of HO-1 with Haemin Alleviates LPS-Stimulated Pro-inflammatory Responses Through Downregulation of p38 Signalling Pathways in Rat Liver. Scand J Immunol 2015; 82:443-51. [DOI: 10.1111/sji.12352] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 08/10/2015] [Indexed: 12/21/2022]
Affiliation(s)
- J. Tang
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - L. Li
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - C.-M. Li
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - J. Wu
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - Y. Sun
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - G.-L. Wang
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
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29
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Sharifnia T, Antoun J, Verriere TGC, Suarez G, Wattacheril J, Wilson KT, Peek RM, Abumrad NN, Flynn CR. Hepatic TLR4 signaling in obese NAFLD. Am J Physiol Gastrointest Liver Physiol 2015; 309:G270-8. [PMID: 26113297 PMCID: PMC4537925 DOI: 10.1152/ajpgi.00304.2014] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 06/11/2015] [Indexed: 02/08/2023]
Abstract
Nonalcoholic fatty liver disease occurs frequently in the setting of metabolic syndrome, but the factors leading to nonalcoholic steatohepatitis (NASH) are not fully understood. This study investigated Toll-like receptor 4 (TLR4) signaling in human liver with the goal of delineating whether activation of this pathway segregates those with nonalcoholic fatty liver from those with NASH. Experiments were performed using liver biopsy tissue obtained from class III obese subjects undergoing bariatric surgery, and extended to an immortalized human hepatocyte HepaRG cell line and primary human hepatocytes. The bacterial endotoxin lipopolysaccharide (LPS) and total free fatty acid levels were significantly increased in plasma of NASH patients. TLR4 mRNA levels were significantly increased in subjects with NASH compared with NAFL as was interferon regulatory factor (IRF) 3 in the myeloid differentiation factor 88-independent signaling pathway. In HepaRG cells, nuclear factor-κB (NF-κB) nuclear translocation and functional activity increased following treatment with the fatty acid, palmitate, and following exposure to LPS compared with hepatocytes stimulated with a lipogenic treatment that induced de novo lipogenesis. Palmitate and LPS induction of NF-κB activity was partially attenuated by chemical- or small-interfering RNA-mediated inhibition of TLR4. Expression of TLR4 and its downstream mediators was upregulated with palmitate and LPS. Similar results were observed using primary human hepatocytes from a lean donor. Interestingly, NF-κB activity assays showed obese donor hepatocytes were resistant to chemical TLR4 inhibition. In conclusion, TLR4 expression is upregulated in a large cohort of NASH patients, compared with those with NAFL, and this occurs within the setting of increased LPS and fatty acids.
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Affiliation(s)
- Torfay Sharifnia
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Joseph Antoun
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Thomas G. C. Verriere
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Giovanni Suarez
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Julia Wattacheril
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Keith T. Wilson
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; ,3Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Richard M. Peek
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Naji N. Abumrad
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Charles R. Flynn
- 2Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and
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30
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Abstract
Nonalcoholic fatty liver disease occurs frequently in the setting of metabolic syndrome, but the factors leading to nonalcoholic steatohepatitis (NASH) are not fully understood. This study investigated Toll-like receptor 4 (TLR4) signaling in human liver with the goal of delineating whether activation of this pathway segregates those with nonalcoholic fatty liver from those with NASH. Experiments were performed using liver biopsy tissue obtained from class III obese subjects undergoing bariatric surgery, and extended to an immortalized human hepatocyte HepaRG cell line and primary human hepatocytes. The bacterial endotoxin lipopolysaccharide (LPS) and total free fatty acid levels were significantly increased in plasma of NASH patients. TLR4 mRNA levels were significantly increased in subjects with NASH compared with NAFL as was interferon regulatory factor (IRF) 3 in the myeloid differentiation factor 88-independent signaling pathway. In HepaRG cells, nuclear factor-κB (NF-κB) nuclear translocation and functional activity increased following treatment with the fatty acid, palmitate, and following exposure to LPS compared with hepatocytes stimulated with a lipogenic treatment that induced de novo lipogenesis. Palmitate and LPS induction of NF-κB activity was partially attenuated by chemical- or small-interfering RNA-mediated inhibition of TLR4. Expression of TLR4 and its downstream mediators was upregulated with palmitate and LPS. Similar results were observed using primary human hepatocytes from a lean donor. Interestingly, NF-κB activity assays showed obese donor hepatocytes were resistant to chemical TLR4 inhibition. In conclusion, TLR4 expression is upregulated in a large cohort of NASH patients, compared with those with NAFL, and this occurs within the setting of increased LPS and fatty acids.
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31
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Walley KR, Thain KR, Russell JA, Reilly MP, Meyer NJ, Ferguson JF, Christie JD, Nakada TA, Fjell CD, Thair SA, Cirstea MS, Boyd JH. PCSK9 is a critical regulator of the innate immune response and septic shock outcome. Sci Transl Med 2015; 6:258ra143. [PMID: 25320235 DOI: 10.1126/scitranslmed.3008782] [Citation(s) in RCA: 257] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A decrease in the activity of proprotein convertase subtilisin/kexin type 9 (PCSK9) increases the amount of low-density lipoprotein (LDL) receptors on liver cells and, therefore, LDL clearance. The clearance of lipids from pathogens is related to endogenous lipid clearance; thus, PCSK9 may also regulate removal of pathogen lipids such as lipopolysaccharide (LPS). Compared to controls, Pcsk9 knockout mice displayed decreases in inflammatory cytokine production and in other physiological responses to LPS. In human liver cells, PCSK9 inhibited LPS uptake, a necessary step in systemic clearance and detoxification. Pharmacological inhibition of PCSK9 improved survival and inflammation in murine polymicrobial peritonitis. Human PCSK9 loss-of-function genetic variants were associated with improved survival in septic shock patients and a decrease in inflammatory cytokine response both in septic shock patients and in healthy volunteers after LPS administration. The PCSK9 effect was abrogated in LDL receptor (LDLR) knockout mice and in humans who are homozygous for an LDLR variant that is resistant to PCSK9. Together, our results show that reduced PCSK9 function is associated with increased pathogen lipid clearance via the LDLR, a decreased inflammatory response, and improved septic shock outcome.
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Affiliation(s)
- Keith R Walley
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada.
| | - Katherine R Thain
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada
| | - James A Russell
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada
| | - Muredach P Reilly
- Cardiovascular Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Nuala J Meyer
- Pulmonary, Allergy, and Critical Care Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA. Center for Translational Lung Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jane F Ferguson
- Cardiovascular Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jason D Christie
- Pulmonary, Allergy, and Critical Care Division, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA. Center for Translational Lung Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA. Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Taka-aki Nakada
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, Chiba 260-8677, Japan
| | - Chris D Fjell
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada
| | - Simone A Thair
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada
| | - Mihai S Cirstea
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada
| | - John H Boyd
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver V6Z 1Y6, Canada
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32
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Espinosa-Carrasco G, Villard M, Le Saout C, Louis-Plence P, Vicente R, Hernandez J. Systemic LPS Translocation Activates Cross-Presenting Dendritic Cells but Is Dispensable for the Breakdown of CD8+ T Cell Peripheral Tolerance in Irradiated Mice. PLoS One 2015; 10:e0130041. [PMID: 26075613 PMCID: PMC4468093 DOI: 10.1371/journal.pone.0130041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/15/2015] [Indexed: 11/26/2022] Open
Abstract
Lymphodepletion is currently used to enhance the efficacy of cytotoxic T lymphocyte adoptive transfer immunotherapy against cancer. This beneficial effect of conditioning regimens is due, at least in part, to promoting the breakdown of peripheral CD8+ T cell tolerance. Lymphodepletion by total body irradiation induces systemic translocation of commensal bacteria LPS from the gastrointestinal tract. Since LPS is a potent activator of the innate immune system, including antigen presenting dendritic cells, we hypothesized that LPS translocation could be required for the breakdown of peripheral tolerance observed in irradiated mice. To address this issue, we have treated irradiated mice with antibiotics in order to prevent LPS translocation and utilized them in T cell adoptive transfer experiments. Surprisingly, we found that despite of completely blocking LPS translocation into the bloodstream, antibiotic treatment did not prevent the breakdown of peripheral tolerance. Although irradiation induced the activation of cross-presenting CD8+ dendritic cells in the lymphoid tissue, LPS could not solely account for this effect. Activation of dendritic cells by mechanisms other than LPS translocation is sufficient to promote the differentiation of potentially autoreactive CD8+ T cells into effectors in irradiated mice. Our data indicate that LPS translocation is dispensable for the breakdown of CD8+ T cell tolerance in irradiated mice.
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Affiliation(s)
- Gabriel Espinosa-Carrasco
- Inserm U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, F-34295, France
- Université Montpellier, UFR de Médecine, Montpellier, F-34000, France
| | - Marine Villard
- Inserm U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, F-34295, France
- Université Montpellier, UFR de Médecine, Montpellier, F-34000, France
| | - Cecile Le Saout
- CMRS/Laboratory of Immunoregulation, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Pascale Louis-Plence
- Inserm U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, F-34295, France
- Université Montpellier, UFR de Médecine, Montpellier, F-34000, France
| | - Rita Vicente
- Inserm U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, F-34295, France
- Université Montpellier, UFR de Médecine, Montpellier, F-34000, France
| | - Javier Hernandez
- Inserm U1183, Institute for Regenerative Medicine and Biotherapy, Montpellier, F-34295, France
- Université Montpellier, UFR de Médecine, Montpellier, F-34000, France
- * E-mail:
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Ren W, Wang X, Zhang A, Li C, Chen G, Ge X, Pan K, Dong JH. Selective bowel decontamination improves the survival of 90% hepatectomy in rats. J Surg Res 2015; 195:454-64. [DOI: 10.1016/j.jss.2015.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 12/12/2014] [Accepted: 01/13/2015] [Indexed: 12/23/2022]
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Chang G, Zhang K, Xu T, Jin D, Seyfert HM, Shen X, Zhuang S. Feeding a high-grain diet reduces the percentage of LPS clearance and enhances immune gene expression in goat liver. BMC Vet Res 2015; 11:67. [PMID: 25889631 PMCID: PMC4414381 DOI: 10.1186/s12917-015-0376-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/26/2015] [Indexed: 01/06/2023] Open
Abstract
Background The effects of feeding a high-grain (HG) diet on lipopolysaccharide (LPS) clearance and innate immune defence responses in the liver remain unclear. Therefore, we conducted the present study in which twelve female goats were randomly assigned to either a treatment group fed a HG diet (60% grain, n = 6) or a control group fed a low grain diet (LG; 40% grain, n = 6) for 6 weeks. Catheters were installed in the mesenteric, portal and hepatic veins, as well as one femoral artery of the goats, for determining blood flow and net clearance rate of LPS in the liver. Plasma and tissue samples were collected in the week 6 for analyzing pro-inflammatory cytokines, acute phase protein and biochemical parameters, as well as expression of genes involved in immune response. Result HG diet feeding increased blood flow and LPS concentration in the portal vein, hepatic vein and artery. Hepatic net LPS clearance showed that HG diet feeding elevated the rate of hepatic LPS clearance, but decreased the percentage of removed LPS accounting for the total entry of LPS into the liver. Our results demonstrated that the feeding of HG diet increased plasma concentrations of pro-inflammatory cytokines and acute phase proteins and triggered a systemic inflammatory response. In addition, peripheral blood plasma concentrations of alanine aminotransferase, alkaline phosphatase and total bilirubin were increased in the HG group compared to the LG group. This indicated that the impairment of hepatocytes occurred after 6 weeks of HG diet feeding. The expression of genes involved in immune response and Toll-like receptor (TLR)4 protein in the liver was up-regulated in the HG group compared to the LG group, indicating that increased entry of LPS enhanced hepatic immune defence responses and contributed to hepatic inflammatory responses. Conclusion These results provide insight into the capacity of the liver to clear LPS. The increased entry of LPS into liver enhanced hepatic immune defence responses, thereby elevated the rate of LPS clearance. However, the reduction of the percentage of hepatic LPS clearance could be due to the formation of hepatocyte lesion during HG diet feeding.
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Affiliation(s)
- Guangjun Chang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR, China.
| | - Kai Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR, China.
| | - Tianle Xu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR, China.
| | - Di Jin
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR, China.
| | - Hans-Martin Seyfert
- Leibniz Institute for Farm Animal Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
| | - Xiangzhen Shen
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR, China.
| | - Su Zhuang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, PR, China.
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Pol JG, Lekbaby B, Redelsperger F, Klamer S, Mandouri Y, Ahodantin J, Bieche I, Lefevre M, Souque P, Charneau P, Gadessaud N, Kremsdorf D, Soussan P. Alternative splicing-regulated protein of hepatitis B virus hacks the TNF-α-stimulated signaling pathways and limits the extent of liver inflammation. FASEB J 2015; 29:1879-89. [PMID: 25630972 DOI: 10.1096/fj.14-258715] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 12/28/2014] [Indexed: 12/31/2022]
Abstract
Hepatitis B splicing-regulated protein (HBSP) of the hepatitis B virus (HBV) was uncovered a few years ago but its function remains unknown. HBSP expression occurs from a spliced viral transcript that increases during the course of liver disease. This study aimed at characterizing the impact of HBSP on cellular signaling pathways in vitro and on liver pathogenesis in transgenic (Tg) mice. By RT-qPCR array, NF-κB-inducible genes appeared modulated in HepG2 cells transduced with a HBSP-encoding lentivirus. Using luciferase and Western blot assays, we observed a decreased activation of the NF-κB pathway in HBSP-expressing cells following TNF-α treatment, as illustrated by lower levels of phosphorylated IκB-α. Meanwhile, the level of phosphorylated JNK increased together with the sensitivity to apoptosis. The contrasting effects on JNK and IκB-α activation upon TNF-α stimulation matched with a modulated maturation of TGF-β-activated kinase 1 (TAK1) kinase, assessed by 2-dimensional SDS-PAGE. Inhibition of the NF-κB pathway by HBSP was confirmed in the liver of HBSP Tg mice and associated with a significant decrease of chemically induced chronic liver inflammation, as assessed by immunohistochemistry. In conclusion, HBSP contributes to limit hepatic inflammation during chronic liver disease and may favor HBV persistence by evading immune response.
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Affiliation(s)
- Jonathan G Pol
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Bouchra Lekbaby
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - François Redelsperger
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Sofieke Klamer
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Yassmina Mandouri
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - James Ahodantin
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Ivan Bieche
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Marine Lefevre
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Philippe Souque
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Pierre Charneau
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Noémie Gadessaud
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Dina Kremsdorf
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
| | - Patrick Soussan
- *INSERM U845, Pathogenèse des Hépatites Virales B et Immunothérapie, Paris, France; Institut Pasteur, Département de Virologie, Paris, France; Université Paris-Descartes, Centre Hospitalier Universitaire Necker, Paris, France; Laboratoire de Génétique Moléculaire, Faculté des Sciences Pharmaceutiques, Paris, France; Service d'Anatomo-pathologie, Hôpital Tenon, Paris, France; Virologie Moléculaire et Vectorologie, Centre National de la Recherche Scientifique - Unité de Recherche Associée 3015, Institut Pasteur, Paris, France; Plateforme d'Histologie, Laboratoire L-RB126, Paris, France; **Laboratoire de Virologie, Hôpital Tenon, Paris, France; and Université Pierre et Marie Curie, Centre Hospitalier Universitaire Tenon, Paris France
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Mgcina LS, Dubery IA, Piater LA. Comparative conventional- and quantum dot-labeling strategies for LPS binding site detection in Arabidopsis thaliana mesophyll protoplasts. FRONTIERS IN PLANT SCIENCE 2015; 6:335. [PMID: 26029233 PMCID: PMC4428080 DOI: 10.3389/fpls.2015.00335] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/28/2015] [Indexed: 05/10/2023]
Abstract
Lipopolysaccharide (LPS) from Gram-negative bacteria is recognized as a microbe-associated molecular pattern (MAMP) and not only induces an innate immune response in plants, but also stimulates the development of characteristic defense responses. However, identification and characterization of a cell surface LPS-receptor/binding site, as described in mammals, remains elusive in plants. As an amphiphilic, macromolecular lipoglycan, intact LPS potentially contains three MAMP-active regions, represented by the O-polysaccharide chain, the core and the lipid A. Binding site studies with intact labeled LPS were conducted in Arabidopsis thaliana protoplasts and quantified using flow cytometry fluorescence changes. Quantum dots (Qdots), which allow non-covalent, hydrophobic labeling were used as a novel strategy in this study and compared to covalent, hydrophilic labeling with Alexa 488. Affinity for LPS-binding sites was clearly demonstrated by concentration-, temperature-, and time-dependent increases in protoplast fluorescence following treatment with the labeled LPS. Moreover, this induced fluorescence increase was convincingly reduced following pre-treatment with excess unlabeled LPS, thereby indicating reversibility of LPS binding. Inhibition of the binding process is also reported using endo- and exocytosis inhibitors. Here, we present evidence for the anticipated presence of LPS-specific binding sites in Arabidopsis protoplasts, and furthermore propose Qdots as a more sensitive LPS-labeling strategy in comparison to the conventional Alexa 488 hydrazide label for binding studies.
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Affiliation(s)
| | | | - Lizelle A. Piater
- *Correspondence: Lizelle A. Piater, Department of Biochemistry, University of Johannesburg, Corner of Kingsway and University Road, Auckland Park 2006, Johannesburg, Gauteng, South Africa
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Eftekhari G, Hajiasgharzadeh K, Ahmadi-Soleimani SM, Dehpour AR, Semnanian S, Mani AR. Activation of central muscarinic receptor type 1 prevents development of endotoxin tolerance in rat liver. Eur J Pharmacol 2014; 740:436-41. [PMID: 25008070 DOI: 10.1016/j.ejphar.2014.06.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/24/2014] [Accepted: 06/26/2014] [Indexed: 12/13/2022]
Abstract
Endotoxin tolerance is a mechanism in which cells receiving low doses of endotoxin, enter a transient phase with less inflammatory response to the next endotoxin challenges. Central nervous system is known to modulate systemic inflammation through activation of the cholinergic system; however, the role of central anti-inflammatory pathway in pathophysiology of hepatic endotoxin tolerance is unknown. Our study was designed to assess the effect central muscarinic type 1 receptor (M1) activation on development of endotoxin tolerance in rat liver. Endotoxin tolerance was induced by daily intraperitoneal injection of endotoxin (1 mg/kg) for 5 days. Animals were randomly divided into two groups which received intracerebroventricular injection of either MCNA-343 (an M1 agonist, 5 ng/kg) or saline 1h after intraperitoneal injection of saline or endotoxin. The responsiveness to endotoxin was assessed by measuring hepatic MCP-1 (monocyte chemotactic protein-1), iNOS (inducible nitric oxide synthase) and TNF-α (tumor necrosis-α) mRNA expression 3h after intraperitoneal administration of endotoxin using quantitative RT-PCR. A significant reduction in hepatic expression of MCP-1, iNOS and TNF-α was observed in rats with 5 days endotoxin challenge in comparison with rats given a single dose of endotoxin. There was no significant difference in hepatic expression of MCP-1, iNOS or TNF-α between acute and chronic LPS-treated groups in rats given MCNA-343. Central MCNA-343 stimulation could prevent the induction of hepatic endotoxin tolerance in animals receiving repeated doses of endotoxin. This indicates that M1 cholinergic receptor activation in the central nervous system can modulate endotoxin tolerance in rat liver.
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Affiliation(s)
- Golnar Eftekhari
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Khalil Hajiasgharzadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | | | - Ahmad R Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ali R Mani
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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Chen C, Deng M, Sun Q, Loughran P, Billiar TR, Scott MJ. Lipopolysaccharide stimulates p62-dependent autophagy-like aggregate clearance in hepatocytes. BIOMED RESEARCH INTERNATIONAL 2014; 2014:267350. [PMID: 24683544 PMCID: PMC3934718 DOI: 10.1155/2014/267350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 11/18/2013] [Accepted: 11/26/2013] [Indexed: 01/11/2023]
Abstract
Impairment of autophagy has been associated with liver injury. TLR4-stimulation by LPS upregulates autophagy in hepatocytes, although the signaling pathways involved remain elusive. The objective of this study was to determine the signaling pathway leading to LPS-stimulated autophagy in hepatocytes. Cell lysates from livers of wild type (WT; C57BL/6) mice given LPS (5 mg/kg-IP) and hepatocytes from WT, TLR4ko, and MyD88ko mice treated with LPS (100 ng/mL) up to 24 h were collected. LC3II, p62/SQSTM1, Nrf2, and beclin1 levels were determined by immunoblot, immunofluorescence, and qPCR. Autophagy-like activation was measured by GFP-LC3-puncta formation and LC3II-expression. Beclin1, Nrf2, p62, MyD88, and TIRAP were knocked-down using siRNA. LC3II-expression increased in both liver and hepatocytes after LPS and was dependent on TLR4. Beclin1 expression did not increase after LPS in hepatocytes and beclin1-knockdown did not affect LC3II levels. In hepatocytes given LPS, expression of p62 increased and p62 colocalized with LC3. p62-knockdown prevented LC3II puncta formation. LPS-induced LC3II/p62-puncta also required MyD88/TIRAP signaling and localization of both Nrf2 and NF κ B transcription factors to the nucleus to upregulate p62-expression. Therefore, TLR4-activation by LPS in hepatocytes induces a p62-mediated, not beclin1-mediated, autophagy-like clearance pathway that is hepatoprotective by clearing aggregate-prone or misfolded proteins from the cytosol and preserving energy homeostasis under stress.
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Affiliation(s)
- Christine Chen
- Department of Surgery, University of Pittsburgh, NW607 MUH, 3459 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Meihong Deng
- Department of Surgery, University of Pittsburgh, NW607 MUH, 3459 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Qian Sun
- Department of Surgery, University of Pittsburgh, NW607 MUH, 3459 Fifth Avenue, Pittsburgh, PA 15213, USA
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, NW607 MUH, 3459 Fifth Avenue, Pittsburgh, PA 15213, USA
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Timothy R. Billiar
- Department of Surgery, University of Pittsburgh, NW607 MUH, 3459 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Melanie J. Scott
- Department of Surgery, University of Pittsburgh, NW607 MUH, 3459 Fifth Avenue, Pittsburgh, PA 15213, USA
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Li B, Yu M, Pan X, Ren C, Peng W, Li X, Jiang W, Zheng J, Zhou H. Artesunate reduces serum lipopolysaccharide in cecal ligation/puncture mice via enhanced LPS internalization by macrophages through increased mRNA expression of scavenger receptors. Int J Mol Sci 2014; 15:1143-61. [PMID: 24441569 PMCID: PMC3907860 DOI: 10.3390/ijms15011143] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/02/2014] [Accepted: 01/09/2014] [Indexed: 11/24/2022] Open
Abstract
Innate immunity is the first line of defense in human beings against pathogen infection; monocytes/macrophages are the primary cells of the innate immune system. Recently, macrophages/monocytes have been discovered to participate in LPS clearance, and the clearance efficiency determines the magnitude of the inflammatory response and subsequent organ injury. Previously, we reported that artesunate (AS) protected sepsis mice against heat-killed E. coli challenge. Herein, we further confirmed that AS protected cecal ligation/puncture (CLP) sepsis mice. Its protection on sepsis mice was related to not only reduction of pro-inflammatory cytokines and serum LPS levels but also improvement of liver function. Based on the fact that AS did not directly bind and neutralize LPS, we hypothesized that the reduction of serum LPS level might be related to enhancement of LPS internalization and subsequent detoxification. Our results showed that AS increased FITC-LPS internalization by peritoneal macrophage and liver Kupffer cell, but enhancement of LPS internalization by AS was not related to the clathrin-dependent pathway. However, AS induced mRNA expression of important scavenger receptors (SRs); SR-A and MARCO mRNA expression was upregulated, suggesting that AS enhancement of LPS internalization and inhibition of pro-inflammatory cytokines was related to changes in mRNA expression of SRs.
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Affiliation(s)
- Bin Li
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Mengchen Yu
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Xichun Pan
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Chuanliang Ren
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Wei Peng
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Xiaoli Li
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Weiwei Jiang
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Jiang Zheng
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Hong Zhou
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
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Sun Y, Li H, Sun MJ, Zheng YY, Gong DJ, Xu Y. Endotoxin Tolerance Induced by Lipopolysaccharides Derived from Porphyromonas gingivalis and Escherichia coli: Alternations in Toll-Like Receptor 2 and 4 Signaling Pathway. Inflammation 2013; 37:268-76. [DOI: 10.1007/s10753-013-9737-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gandhi A, Moorthy B, Ghose R. Drug disposition in pathophysiological conditions. Curr Drug Metab 2013; 13:1327-44. [PMID: 22746301 DOI: 10.2174/138920012803341302] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 04/04/2012] [Accepted: 04/19/2012] [Indexed: 12/19/2022]
Abstract
Expression and activity of several key drug metabolizing enzymes (DMEs) and transporters are altered in various pathophysiological conditions, leading to altered drug metabolism and disposition. This can have profound impact on the pharmacotherapy of widely used clinically relevant medications in terms of safety and efficacy by causing inter-individual variabilities in drug responses. This review article highlights altered drug disposition in inflammation and infectious diseases, and commonly encountered disorders such as cancer, obesity/diabetes, fatty liver diseases, cardiovascular diseases and rheumatoid arthritis. Many of the clinically relevant drugs have a narrow therapeutic index. Thus any changes in the disposition of these drugs may lead to reduced efficacy and increased toxicity. The implications of changes in DMEs and transporters on the pharmacokinetics/pharmacodynamics of clinically-relevant medications are also discussed. Inflammation-mediated release of pro-inflammatory cytokines and activation of toll-like receptors (TLRs) are known to play a major role in down-regulation of DMEs and transporters. Although the mechanism by which this occurs is unclear, several studies have shown that inflammation-associated cell-signaling pathway and its interaction with basal transcription factors and nuclear receptors in regulation of DMEs and transporters play a significant role in altered drug metabolism. Altered regulation of DMEs and transporters in a multitude of disease states will contribute towards future development of powerful in vitro and in vivo tools in predicting the drug response and opt for better drug design and development. The goal is to facilitate a better understanding of the mechanistic details underlying the regulation of DMEs and transporters in pathophysiological conditions.
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Affiliation(s)
- Adarsh Gandhi
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX 77030, USA
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Jing J, Yang IV, Hui L, Patel JA, Evans CM, Prikeris R, Kobzik L, O'Connor BP, Schwartz DA. Role of macrophage receptor with collagenous structure in innate immune tolerance. THE JOURNAL OF IMMUNOLOGY 2013; 190:6360-7. [PMID: 23667110 DOI: 10.4049/jimmunol.1202942] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Macrophages play a key role in host defense against microbes, in part, through phagocytosis. Macrophage receptor with collagenous structure (MARCO) is a scavenger receptor on the cell surface of macrophages that mediates opsonin-independent phagocytosis. The goal of our study is to investigate the role of MARCO in LPS or lipotechoic acid-induced macrophage tolerance. Although it has been established that expression of MARCO and phagocytosis is increased in tolerant macrophages, the transcriptional regulation and biological role of MARCO in tolerant macrophages have not been investigated. In this study, we confirm that tolerized mouse bone marrow-derived macrophages (BMDM) selectively increase expression of MARCO (both transcript and cell surface receptor) and increase phagocytosis. We found that H3K4me3 dynamic modification of a promoter site of MARCO was increased in tolerized BMDM. Blocking methylation by treatment with 5-aza-2'-deoxycytidine resulted in reduced H3K4me3 binding in the promoter of MARCO, decreased expression of MARCO, and impaired phagocytosis in tolerized BMDM. However, 5-aza-2'-deoxycytidine had no effect on the inflammatory component of innate immune tolerance. In aggregate, we found that histone methylation was critical to MARCO expression and phagocytosis in tolerized macrophages, but did not affect the inflammatory component of innate immune tolerance.
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Affiliation(s)
- Jian Jing
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
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43
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Deng M, Scott MJ, Loughran P, Gibson G, Sodhi C, Watkins S, Hackam D, Billiar TR. Lipopolysaccharide clearance, bacterial clearance, and systemic inflammatory responses are regulated by cell type-specific functions of TLR4 during sepsis. THE JOURNAL OF IMMUNOLOGY 2013; 190:5152-60. [PMID: 23562812 DOI: 10.4049/jimmunol.1300496] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The morbidity associated with bacterial sepsis is the result of host immune responses to pathogens, which are dependent on pathogen recognition by pattern recognition receptors, such as TLR4. TLR4 is expressed on a range of cell types, yet the mechanisms by which cell-specific functions of TLR4 lead to an integrated sepsis response are poorly understood. To address this, we generated mice in which TLR4 was specifically deleted from myeloid cells (LysMTLR4KO) or hepatocytes (HCTLR4KO) and then determined survival, bacterial counts, host inflammatory responses, and organ injury in a model of cecal ligation and puncture (CLP), with or without antibiotics. LysM-TLR4 was required for phagocytosis and efficient bacterial clearance in the absence of antibiotics. Survival, the magnitude of the systemic and local inflammatory responses, and liver damage were associated with bacterial levels. HCTLR4 was required for efficient LPS clearance from the circulation, and deletion of HCTLR4 was associated with enhanced macrophage phagocytosis, lower bacterial levels, and improved survival in CLP without antibiotics. Antibiotic administration during CLP revealed an important role for hepatocyte LPS clearance in limiting sepsis-induced inflammation and organ injury. Our work defines cell type-selective roles for TLR4 in coordinating complex immune responses to bacterial sepsis and suggests that future strategies for modulating microbial molecule recognition should account for varying roles of pattern recognition receptors in multiple cell populations.
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Affiliation(s)
- Meihong Deng
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Haddadian Z, Eftekhari G, Mazloom R, Jazaeri F, Dehpour AR, Mani AR. Effect of endotoxin on heart rate dynamics in rats with cirrhosis. Auton Neurosci 2013; 177:104-13. [PMID: 23511062 DOI: 10.1016/j.autneu.2013.02.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 02/11/2013] [Accepted: 02/25/2013] [Indexed: 12/11/2022]
Abstract
Reduced heart rate variability (HRV) is a hallmark of systemic inflammation which carries negative prognostic information in sepsis. Decreased HRV is associated with partial uncoupling of cardiac pacemaker from cholinergic neural control during systemic inflammation. Sepsis is a common complication in liver cirrhosis with high mortality. The present study was aimed to explore the hypothesis that endotoxin uncouples cardiac pacemaker from autonomic neural control and reduces HRV in an experimental model of cirrhosis. Cirrhosis was induced by surgical ligation of the bile duct in rats. Cirrhotic rats were given intraperitoneal injection of either saline or lipopolysaccharide (endotoxin, 1mg/kg). Changes in HRV indices were studied in conscious rats using implanted telemetric probes. The atria were isolated and chronotropic responsiveness to cholinergic stimulation was assessed in vitro. Endotoxin injection induced a significant tachycardia and decreased short-term and long-term HRV indices in control rats. However, endotoxin was unable to increase heart rate in cirrhotic animals. In contrast with control rats, endotoxin induced biphasic changes in short-term HRV in cirrhotic rats. Acute endotoxin challenge reduced long-term HRV with 60-min delay in comparison with control animals. Endotoxin injection was associated with a significant hypo-responsiveness to cholinergic stimulation in control rats in vitro. Endotoxin did not change atrial chronotropic responsiveness to cholinergic stimulation in cirrhotic rats. Our data shows that cirrhosis is associated with development of tolerance to cardiac chronotropic effect of endotoxin in rats.
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Affiliation(s)
- Zahra Haddadian
- Department of Physiology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Jazaeri F, Tavangar SM, Ghazi-Khansari M, Khorramizadeh MR, Mani AR, Dehpour AR. Cirrhosis is associated with development of tolerance to cardiac chronotropic effect of endotoxin in rats. Liver Int 2013; 33:368-74. [PMID: 23311391 DOI: 10.1111/liv.12039] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 11/03/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND/AIMS Sepsis is a common complication of cirrhosis with a high mortality. Cirrhosis is associated with cardiac chronotropic and inotropic dysfunction, which is known as cirrhotic cardiomyopathy and might be linked to endotoxaemia. This study was aimed to explore the hypothesis that the inflammatory response induced by administration of low dose of lipopolysaccharide (LPS) exacerbates cardiac chronotropic dysfunction in cirrhotic rats; and if so, whether this is associated with altered cardiac toll-like receptor expression. METHODS Cirrhosis was induced by surgical ligation of the bile duct in male Wister rats. Four weeks after bile duct ligation or sham surgery, the subjects were given intraperitoneal injection of either saline or LPS (0.1 mg/kg). Five hours after LPS injection, the atria were isolated and spontaneously beating rate and chronotropic responsiveness to β-adrenergic stimulation was assessed using standard organ bath. The expression of toll-like receptor 4 (TLR4) was assessed the atria using immunohistochemistry as well as quantitative RT-PCR. RESULTS LPS injection could induce a significant hypo-responsiveness to adrenergic stimulation in sham-operated rats. However, in cirrhotic rats, the chronotropic responses did not change after acute injection of LPS. Immunohistochemical study showed that TLR4 is mainly expressed in the myocardium in control atria and its expression is markedly decreased in myocardial layer following chronic bile duct ligation. CONCLUSION Our data showed that cirrhosis is associated with development of tolerance to cardiac chronotropic effect of LPS in rats and this might be caused by altered localization of TLR4 in myocardium.
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Affiliation(s)
- Farahnaz Jazaeri
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Fang H, Liu A, Sun J, Kitz A, Dirsch O, Dahmen U. Granulocyte colony stimulating factor induces lipopolysaccharide (LPS) sensitization via upregulation of LPS binding protein in rat. PLoS One 2013; 8:e56654. [PMID: 23437199 PMCID: PMC3577878 DOI: 10.1371/journal.pone.0056654] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/12/2013] [Indexed: 01/01/2023] Open
Abstract
Liver is the main organ for lipopolysaccharide (LPS) clearance. Sensitization to LPS is associated with the upregulation of LPS-binding protein (LBP) in animal models. Therefore, we hypothesized that LBP could induce LPS sensitization through enhancing hepatic uptake of LPS. In this study, we examined the role of LBP in pathogenesis of LPS induced systemic inflammatory response syndrome (SIRS). LBP expression was upregulated after granulocyte colony stimulating (G-CSF) pretreatment. The effect of LBP was further confirmed by blockade of LBP using LBP blocking peptide--LBPK95A. After G-CSF pretreatment, upregulation of LBP was observed in bone marrow cells and liver. The G-CSF induced LBP upregulation caused LPS hypersensitization in rats as indicated by higher mortality and severer liver damage. Of note, LBP blockade increased the survival rate and attenuated the liver injury. The LBP induced LPS hypersensitization was associated with increased hepatic uptake of LPS and augmented hepatic expression of LPS receptors, such as toll-like receptor (TLR)-4. Furthermore, LBP mediated early neutrophil infiltration, which led to increased monocyte recruitment in liver after LPS administration. In conclusion, G-CSF induced LBP expression could serve as a new model for investigation of LPS sensitization. We demonstrated the crucial role of LBP upregulation in pathogenesis of LPS induced SIRS.
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Affiliation(s)
- Haoshu Fang
- Experimental Transplantation Surgery, University Hospital of Jena, Jena, Germany
| | - Anding Liu
- Experimental Transplantation Surgery, University Hospital of Jena, Jena, Germany
- Experimental Medicine Center, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Jian Sun
- Experimental Transplantation Surgery, University Hospital of Jena, Jena, Germany
- Department of Hepatobiliopancreatic Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Alexandra Kitz
- Institution of Neuroimmunology, Georg-August-University Gottingen, Gottingen, Germany
| | - Olaf Dirsch
- Institute for Pathology, University Hospital of Jena, Jena, Germany
| | - Uta Dahmen
- Experimental Transplantation Surgery, University Hospital of Jena, Jena, Germany
- * E-mail:
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Kim SM, Sakai T, Dang HV, Tran NH, Ono K, Ishimura K, Fukui K. Nucling, a novel protein associated with NF-κB, regulates endotoxin-induced apoptosis in vivo. J Biochem 2012; 153:93-101. [PMID: 23071121 DOI: 10.1093/jb/mvs119] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Nucling is a proapoptotic protein that regulates the apoptosome and nuclear factor-kappa B (NF-κB) signalling pathways. Strong stimuli, such as Gram-negative bacterial lipopolysaccharide (LPS), induce the simultaneous secretion of cytokines following the activation of NF-κB. Proinflammatory cytokines can induce liver damage through several mechanisms such as increases in oxidative stress and apoptotic reactions leading to tissue necrosis. Herein, we show that Nucling-knockout (KO) mice are resistant to LPS that consistently caused mortality in wild-type (WT) counterparts. Although serum levels of cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 did not differ significantly between WT and Nucling-KO mice after the LPS challenge, hepatocytes of Nucling-KO mice were refractory to LPS- or TNF-α-induced cell death. These results were consistent with the decreased expression of proapoptotic proteins including apoptosis-inducing factor and cleaved form of poly (ADP-ribose) polymerase and terminal deoxynucleotidyl transferase dUTP nick end-labelling positive cells in the liver of Nucling-KO mice after the administration of a lethal dose of LPS. Moreover, the upregulation of NF-κB-regulated anti-apoptotic molecules including cellular inhibitor of apoptosis (cIAP) 1 and cIAP2 was observed in the liver of Nucling-KO mice after LPS treatment. These findings indicate that the Nucling deficiency leads to resistance to apoptosis in liver. We propose that Nucling is important for the induction of apoptosis in cells damaged by cytotoxic stressors through the NF-κB signalling pathway.
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Affiliation(s)
- Sun Mi Kim
- Division of Enzyme Pathophysiology, The Institute for Enzyme Research (KOSOKEN), The University of Tokushima, Graduate School, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan
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Chanthaphavong RS, Loughran PA, Lee TYS, Scott MJ, Billiar TR. A role for cGMP in inducible nitric-oxide synthase (iNOS)-induced tumor necrosis factor (TNF) α-converting enzyme (TACE/ADAM17) activation, translocation, and TNF receptor 1 (TNFR1) shedding in hepatocytes. J Biol Chem 2012; 287:35887-98. [PMID: 22898814 DOI: 10.1074/jbc.m112.365171] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We and others have previously shown that the inducible nitric-oxide synthase (iNOS) and nitric oxide (NO) are hepatoprotective in a number of circumstances, including endotoxemia. In vitro, hepatocytes are protected from tumor necrosis factor (TNF) α-induced apoptosis via cGMP-dependent and cGMP-independent mechanisms. We have shown that the cGMP-dependent protective mechanisms involve the inhibition of death-inducing signaling complex formation. We show here that LPS-induced iNOS expression leads to rapid TNF receptor shedding from the surface of hepatocytes via NO/cGMP/protein kinase G-dependent activation and surface translocation of TNFα-converting enzyme (TACE/ADAM17). The activation of TACE is associated with the up-regulation of iRhom2 as well as the interaction and phosphorylation of TACE and iRhom2, which are also NO/cGMP/protein kinase G-dependent. These findings suggest that one mechanism of iNOS/NO-mediated protection of hepatocytes involves the rapid shedding of TNF receptor 1 to limit TNFα signaling.
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Affiliation(s)
- R Savanh Chanthaphavong
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
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Shao B, Munford RS, Kitchens R, Varley AW. Hepatic uptake and deacylation of the LPS in bloodborne LPS-lipoprotein complexes. Innate Immun 2012; 18:825-33. [PMID: 22441700 DOI: 10.1177/1753425912442431] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Much evidence indicates that bacterial LPS (endotoxin) is removed from the bloodstream mainly by the liver, yet the hepatic uptake mechanisms remain uncertain and controversial. In plasma, LPS can be either 'free' (as aggregates, bacterial membrane fragments or loosely bound to albumin, CD14, or other proteins) or 'bound' (complexed with lipoproteins). Whereas most free LPS is taken up by Kupffer cells (KCs), lipoprotein-bound LPS has seemed to be cleared principally by hepatocytes. Here, we compared the liver's ability to take up and deacylate free LPS aggregates and the LPS in preformed LPS-high density lipoprotein (HDL) complexes. In mice examined from 1 h to 7 d after a small amount of fluorescent (FITC-)LPS was injected into a lateral tail vein, we found FITC-LPS almost entirely within, or adjacent to, KCs. As expected, FITC-LPS complexed with HDL (FITC-LPS-HDL) disappeared more slowly from the circulation and a smaller fraction of the injected dose of FITC-LPS was found in the liver. Unexpectedly, the FITC-LPS injected as FITC-LPS-HDL complexes was also found within sinusoids, adjacent to, or within, KCs. In other experiments, we found that both free and HDL-bound radiolabeled LPS underwent enzymatic deacylation by acyloxyacyl hydrolase (AOAH), the LPS-inactivating enzyme that is principally produced within the liver by KCs. Our observations suggest that KCs and AOAH play important roles in clearing and catabolizing both free LPS and the LPS in circulating LPS-HDL complexes.
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Affiliation(s)
- Baomei Shao
- Department of Internal Medicine, Division of Infectious Diseases, The University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
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50
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Bohne F, Martínez-Llordella M, Lozano JJ, Miquel R, Benítez C, Londoño MC, Manzia TM, Angelico R, Swinkels DW, Tjalsma H, López M, Abraldes JG, Bonaccorsi-Riani E, Jaeckel E, Taubert R, Pirenne J, Rimola A, Tisone G, Sánchez-Fueyo A. Intra-graft expression of genes involved in iron homeostasis predicts the development of operational tolerance in human liver transplantation. J Clin Invest 2011; 122:368-82. [PMID: 22156196 DOI: 10.1172/jci59411] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 10/26/2011] [Indexed: 12/13/2022] Open
Abstract
Following organ transplantation, lifelong immunosuppressive therapy is required to prevent the host immune system from destroying the allograft. This can cause severe side effects and increased recipient morbidity and mortality. Complete cessation of immunosuppressive drugs has been successfully accomplished in selected transplant recipients, providing proof of principle that operational allograft tolerance is attainable in clinical transplantation. The intra-graft molecular pathways associated with successful drug withdrawal, however, are not well defined. In this study, we analyzed sequential blood and liver tissue samples collected from liver transplant recipients enrolled in a prospective multicenter immunosuppressive drug withdrawal clinical trial. Before initiation of drug withdrawal, operationally tolerant and non-tolerant recipients differed in the intra-graft expression of genes involved in the regulation of iron homeostasis. Furthermore, as compared with non-tolerant recipients, operationally tolerant patients exhibited higher serum levels of hepcidin and ferritin and increased hepatocyte iron deposition. Finally, liver tissue gene expression measurements accurately predicted the outcome of immunosuppressive withdrawal in an independent set of patients. These results point to a critical role for iron metabolism in the regulation of intra-graft alloimmune responses in humans and provide a set of biomarkers to conduct drug-weaning trials in liver transplantation.
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Affiliation(s)
- Felix Bohne
- Liver Unit, Hospital Clinic Barcelona, IDIBAPS, CIBEREHD, University of Barcelona, Barcelona, Spain
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