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Huang TQ, Chen YX, Zeng SL, Lin Y, Li F, Jiang ZM, Liu EH. Bergenin Alleviates Ulcerative Colitis By Decreasing Gut Commensal Bacteroides vulgatus-Mediated Elevated Branched-Chain Amino Acids. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:3606-3621. [PMID: 38324392 DOI: 10.1021/acs.jafc.3c09448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Ulcerative colitis is closely associated with the dysregulation of gut microbiota. There is growing evidence that natural products may improve ulcerative colitis by regulating the gut microbiota. In this research, we demonstrated that bergenin, a naturally occurring isocoumarin, significantly ameliorates colitis symptoms in dextran sulfate sodium (DSS)-induced mice. Transcriptomic analysis and Caco-2 cell assays revealed that bergenin could ameliorate ulcerative colitis by inhibiting TLR4 and regulating NF-κB and mTOR phosphorylation. 16S rRNA sequencing and metabolomics analyses revealed that bergenin could improve gut microbiota dysbiosis by decreasing branched-chain amino acid (BCAA) levels. BCAA intervention mediated the mTOR/p70S6K signaling pathway to exacerbate the symptoms of ulcerative colitis in mice. Notably, bergenin greatly decreased the symbiotic bacteria Bacteroides vulgatus (B. vulgatus), and the gavage of B. vulgatus increased BCAA concentrations and aggravated the symptoms of ulcerative colitis in mice. Our findings suggest that gut microbiota-mediated BCAA metabolism plays a vital role in the protective effect of bergenin on ulcerative colitis, providing novel insights for ulcerative colitis prevention through manipulation of the gut microbiota.
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Affiliation(s)
- Tian-Qing Huang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Yu-Xin Chen
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Su-Ling Zeng
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei 230601, China
| | - Yang Lin
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Fei Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
| | - Zheng-Meng Jiang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
- College of Pharmacy, Nanjing University of Chinese Medicine, No. 138 Xianlin Road, Nanjing 210023, China
| | - E-Hu Liu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China
- College of Pharmacy, Nanjing University of Chinese Medicine, No. 138 Xianlin Road, Nanjing 210023, China
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2
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Ganji N, Li B, Lee C, Pierro A. Necrotizing enterocolitis: recent advances in treatment with translational potential. Pediatr Surg Int 2023; 39:205. [PMID: 37247104 DOI: 10.1007/s00383-023-05476-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2023] [Indexed: 05/30/2023]
Abstract
Necrotizing enterocolitis (NEC) is one of the most prevalent and devastating gastrointestinal disorders in neonates. Despite advances in neonatal care, the incidence and mortality due to NEC remain high, highlighting the need to devise novel treatments for this disease. There have been a number of recent advancements in therapeutic approaches for the treatment of NEC; these involve remote ischemic conditioning (RIC), stem cell therapy, breast milk components (human milk oligosaccharides, exosomes, lactoferrin), fecal microbiota transplantation, and immunotherapy. This review summarizes the most recent advances in NEC treatment currently underway as well as their applicability and associated challenges and limitations, with the aim to provide new insight into the paradigm of care for NEC worldwide.
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Affiliation(s)
- Niloofar Ganji
- Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
- Translational Medicine, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - Bo Li
- Translational Medicine, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - Carol Lee
- Translational Medicine, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - Agostino Pierro
- Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.
- Translational Medicine, Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada.
- Division of General and Thoracic Surgery, The Hospital for Sick Children, University of Toronto, 1526-555 University Ave, Toronto, ON, M5G 1X8, Canada.
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3
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Salama AAA, Elgohary R, Fahmy MI. Protocatechuic acid ameliorates lipopolysaccharide-induced kidney damage in mice via downregulation of TLR-4-mediated IKBKB/NF-κB and MAPK/Erk signaling pathways. J Appl Toxicol 2023. [PMID: 36807594 DOI: 10.1002/jat.4447] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/31/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023]
Abstract
Acute kidney injury (AKI) is a very critical cause of death in the whole world. Lipopolysaccharide (LPS) induces kidney damage by activating various deleterious inflammatory and oxidative pathways. Protocatechuic acid, a natural phenolic compound, has shown to exert beneficial effects against oxidative and inflammatory responses. The study aimed to clarify the nephroprotective activity of protocatechuic acid in LPS-induced acute kidney damage in mice. Forty male Swiss mice were allocated in four groups as follows: normal control group; LPS (250 μg/kg, ip)-induced kidney injury group; LPS-injected mice treated with protocatechuic acid (15 mg/kg, po), and LPS-injected mice treated with protocatechuic acid (30 mg/kg, po). Significant toll-like receptor 4 (TLR-4)-mediated activation of IKBKB/NF-κB and MAPK/Erk/COX-2 inflammatory pathways has been observed in kidneys of mice treated with LPS. Oxidative stress was revealed by inhibition of total antioxidant capacity, catalase, nuclear factor erythroid 2-related factor 2 (Nrf2), and NAD(P)H quinone oxidoreductase (NQO1) enzyme along with increased nitric oxide level. In parallel, focal inflammatory effects were shown in between the tubules and glomeruli as well as in the perivascular dilated blood vessels at the cortex affecting the normal morphology of the kidney tissues of LPS-treated mice. However, treatment with protocatechuic acid reduced LPS-induced changes in the aforementioned parameters and restored normal histological features of the affected tissues. In conclusion, our study uncovered that protocatechuic acid has nephroprotective effects in mice with AKI through opposing different inflammatory and oxidative cascades.
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Affiliation(s)
| | - Rania Elgohary
- Narcotics, Ergogenics and Poisons Department, National Research Centre, Cairo, Egypt
| | - Mohamed Ibrahim Fahmy
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Heliopolis University, Cairo, Egypt
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4
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Nango H, Ohtani M. S-1-propenyl-L-cysteine suppresses lipopolysaccharide-induced expression of matrix metalloproteinase-1 through inhibition of tumor necrosis factor-α converting enzyme-epidermal growth factor receptor axis in human gingival fibroblasts. PLoS One 2023; 18:e0284713. [PMID: 37083725 PMCID: PMC10121056 DOI: 10.1371/journal.pone.0284713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 04/05/2023] [Indexed: 04/22/2023] Open
Abstract
Periodontal disease is the most common dental health problem characterized by the destruction of connective tissue and the resorption of alveolar bone resulting from a chronic infection associated with pathogenic bacteria in the gingiva. Aged garlic extract has been reported to improve gingival bleeding index and probing pocket depth score in patients with mild to moderate periodontitis. Although our previous study found that aged garlic extract and its constituents suppressed the tumor necrosis factor-α-induced inflammatory responses in a human gingival epithelial cell line, the mechanism underlying the effect of aged garlic extract on the destruction of the gingiva remains unclear. The present study investigated the effect of S-1-propenyl-L-cysteine, one of the major sulfur bioactive compounds in aged garlic extract, on the lipopolysaccharide-induced expression of matrix metalloproteinases in human gingival fibroblasts HGF-1 cells. Matrix metalloproteinases are well known to be closely related to the destruction of the gingiva. We found that S-1-propenyl-L-cysteine suppressed the lipopolysaccharide-induced expression and secretion of matrix metalloproteinase-1 in HGF-1 cells. In addition, S-1-propenyl-L-cysteine inhibited the lipopolysaccharide-induced phosphorylation of epidermal growth factor receptor and expression of the active form of tumor necrosis factor-α converting enzyme. Furthermore, the inhibitors of epidermal growth factor receptor tyrosine kinase and tumor necrosis factor-α converting enzyme, AG-1478 and TAPI-1, respectively, reduced the lipopolysaccharide-induced protein level of matrix metalloproteinase-1, as did S-1-propenyl-L-cysteine. Taken together, these results suggested that S-1-propenyl-L-cysteine suppresses the lipopolysaccharide-induced expression of matrix metalloproteinase-1 through the blockade of the tumor necrosis factor-α converting enzyme-epidermal growth factor receptor axis in gingival fibroblasts.
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Affiliation(s)
- Hiroshi Nango
- Central Research Institute, Wakunaga Pharmaceutical Co., Ltd., Akitakata, Hiroshima, Japan
| | - Masahiro Ohtani
- Central Research Institute, Wakunaga Pharmaceutical Co., Ltd., Akitakata, Hiroshima, Japan
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5
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Afroz R, Kumarapperuma H, Nguyen QVN, Mohamed R, Little PJ, Kamato D. Lipopolysaccharide acting via toll-like receptor 4 transactivates the TGF-β receptor in vascular smooth muscle cells. Cell Mol Life Sci 2022; 79:121. [PMID: 35122536 PMCID: PMC8817999 DOI: 10.1007/s00018-022-04159-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/06/2022] [Accepted: 01/20/2022] [Indexed: 12/11/2022]
Abstract
Toll-like receptors (TLRs) recognise pathogen‑associated molecular patterns, which allow the detection of microbial infection by host cells. Bacterial-derived toxin lipopolysaccharide activates TLR4 and leads to the activation of the Smad2 transcription factor. The phosphorylation of the Smad2 transcription factor is the result of the activation of the transforming growth factor-β receptor 1 (TGFBR1). Therefore, we sought to investigate LPS via TLR4-mediated Smad2 carboxy terminal phosphorylation dependent on the transactivation of the TGFBR1. The in vitro model used human aortic vascular smooth muscle cells to assess the implications of TLR4 transactivation of the TGFBR1 in vascular pathophysiology. We show that LPS-mediated Smad2 carboxy terminal phosphorylation is inhibited in the presence of TGFBR1 inhibitor, SB431542. Treatment with MyD88 and TRIF pathway antagonists does not affect LPS-mediated phosphorylation of Smad2 carboxy terminal; however, LPS-mediated Smad2 phosphorylation was inhibited in the presence of MMP inhibitor, GM6001, and unaffected in the presence of ROCK inhibitor Y27632 or ROS/NOX inhibitor DPI. LPS via transactivation of the TGFBR1 stimulates PAI-1 mRNA expression. TLRs are first in line to respond to exogenous invading substances and endogenous molecules; our findings characterise a novel signalling pathway in the context of cell biology. Identifying TLR transactivation of the TGFBR1 may provide future insight into the detrimental implications of pathogens in pathophysiology.
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Affiliation(s)
- Rizwana Afroz
- School of Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD, 4102, Australia.,Centre for Cancer Cell Biology and Drug Discovery, Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, QLD, 4111, Australia
| | - Hirushi Kumarapperuma
- School of Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Quang V N Nguyen
- School of Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Raafat Mohamed
- School of Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD, 4102, Australia.,Department of Basic Sciences, College of Dentistry, University of Mosul, Mosul, Iraq
| | - Peter J Little
- School of Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD, 4102, Australia.,Department of Pharmacy, Xinhua College of Sun Yat-Sen University, Tianhe District, Guangzhou, 510520, China.,Sunshine Coast Health Institute, University of the Sunshine Coast, Birtinya, QLD, 4575, Australia
| | - Danielle Kamato
- School of Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD, 4102, Australia.
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6
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Wendimu MY, Alqinyah M, Vella S, Dean P, Almutairi F, Davila-Rivera R, Rayatpisheh S, Wohlschlegel J, Moreno S, Hooks SB. RGS10 physically and functionally interacts with STIM2 and requires store-operated calcium entry to regulate pro-inflammatory gene expression in microglia. Cell Signal 2021; 83:109974. [PMID: 33705894 DOI: 10.1016/j.cellsig.2021.109974] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/19/2021] [Accepted: 03/04/2021] [Indexed: 01/14/2023]
Abstract
Chronic activation of microglia is a driving factor in the progression of neuroinflammatory diseases, and mechanisms that regulate microglial inflammatory signaling are potential targets for novel therapeutics. Regulator of G protein Signaling 10 is the most abundant RGS protein in microglia, where it suppresses inflammatory gene expression and reduces microglia-mediated neurotoxicity. In particular, microglial RGS10 downregulates the expression of pro-inflammatory mediators including cyclooxygenase 2 (COX-2) following stimulation with lipopolysaccharide (LPS). However, the mechanism by which RGS10 affects inflammatory signaling is unknown and is independent of its canonical G protein targeted mechanism. Here, we sought to identify non-canonical RGS10 interacting partners that mediate its anti-inflammatory mechanism. Through RGS10 co-immunoprecipitation coupled with mass spectrometry, we identified STIM2, an endoplasmic reticulum (ER) localized calcium sensor and a component of the store-operated calcium entry (SOCE) machinery, as a novel RGS10 interacting protein in microglia. Direct immunoprecipitation experiments confirmed RGS10-STIM2 interaction in multiple microglia and macrophage cell lines, as well as in primary cells, with no interaction observed with the homologue STIM1. We further determined that STIM2, Orai channels, and the calcium-dependent phosphatase calcineurin are essential for LPS-induced COX-2 production in microglia, and this pathway is required for the inhibitory effect of RGS10 on COX-2. Additionally, our data demonstrated that RGS10 suppresses SOCE triggered by ER calcium depletion and that ER calcium depletion, which induces SOCE, amplifies pro-inflammatory genes. In addition to COX-2, we also show that RGS10 suppresses the expression of pro-inflammatory cytokines in microglia in response to thrombin and LPS stimulation, and all of these effects require SOCE. Collectively, the physical and functional links between RGS10 and STIM2 suggest a complex regulatory network connecting RGS10, SOCE, and pro-inflammatory gene expression in microglia, with broad implications in the pathogenesis and treatment of chronic neuroinflammation.
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Affiliation(s)
- Menbere Y Wendimu
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States of America
| | - Mohammed Alqinyah
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States of America
| | - Stephen Vella
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, United States of America
| | - Phillip Dean
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States of America
| | - Faris Almutairi
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States of America
| | - Roseanne Davila-Rivera
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States of America
| | - Shima Rayatpisheh
- Department of Biological Chemistry, University of California, Los Angeles 90095, United States of America
| | - James Wohlschlegel
- Department of Biological Chemistry, University of California, Los Angeles 90095, United States of America
| | - Silvia Moreno
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, United States of America
| | - Shelley B Hooks
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States of America.
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7
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Dai M, Hu S, Liu CF, Jiang L, Yu W, Li ZL, Guo W, Tang R, Dong CY, Wu TH, Deng WG. BPTF cooperates with p50 NF-κB to promote COX-2 expression and tumor cell growth in lung cancer. Am J Transl Res 2019; 11:7398-7409. [PMID: 31934287 PMCID: PMC6943470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
Cyclooxygenase-2 (COX-2) is overexpressed in most human cancers, but its precise regulatory mechanism in cancer cells remains unclear. The aims of this study are to discover and identify the new regulatory factors which bind to the COX-2 promoter and regulate COX-2 expression and cancer cell growth, and to elucidate the mechanisms of action of these factors in lung cancer. In this study, the COX-2 promoter-binding protein BPTF (bromodomain PHD finger transcription factor) was detected, identified and verified by biotin-streptavidin-agarose pulldown, mass spectrum analysis and chromatin immunoprecipitation (ChIP) in lung cancer cells, respectively. The expressions of COX-2 and BPTF in lung cancer cell lines, mouse tumor tissues and human clinical samples were detected by RT-PCR, Western blot and immunohistochemistry assays. The interaction of BPTF with NF-kB was analyzed by immunoprecipitation and confocal immunofluorescence assays. We discovered and identified BPTF as a new COX-2 promoter-binding protein in human lung cancer cells. Knockdown of BPTF inhibited COX-2 promoter activity and COX-2 expression in lung cancer cells in vitro and in vivo. We also found that BPTF functioned as a transcriptional regulator through its interaction with the p50 subunit of NF-kB. Knockdown of BPTF abrogated the binding of p50 to the COX-2 promoter, while the inhibition of p50 activity abolished the decreased trend of COX-2 expression and lung cancer cell proliferation caused by BPTF silencing. Moreover, we showed that the expressions of BPTF and COX-2 in tumor tissues of lung cancer patients were positively correlated, and high co-expression of BPTF and COX-2 predicted poor prognosis in lung cancer patients. Collectively, our results indicated that BPTF cooperated with p50 NF-κB to regulate COX-2 expression and lung cancer growth, suggesting that the BPTF/p50/COX-2 axis could be a potential therapeutic target for lung cancer.
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Affiliation(s)
- Meng Dai
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
- Dalian Municipal Central HospitalDalian, China
| | - Sheng Hu
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
| | | | - Ling Jiang
- Dalian Municipal Central HospitalDalian, China
| | - Wendan Yu
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
| | | | - Wei Guo
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
| | - Ranran Tang
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
| | - Cheng-Yong Dong
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
| | - Tai-Hua Wu
- The First Affiliated Hospital and Institute of Cancer Stem Cell, Dalian Medical UniversityDalian, China
| | - Wu-Guo Deng
- Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center of Cancer MedicineGuangzhou, China
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8
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Akinsulire O, Perides G, Anez-Bustillos L, Cluette-Brown J, Nedder A, Pollack E, Singh P, Liu Y, Sanchez-Fernandez LL, Obregon E, Bicak E, Kiefer S, Yakah W, Gutierrez HV, Dao DT, Vurma M, Ehling S, Gordon D, DeMichele S, Freedman SD, Martin CR. Early Enteral Administration of a Complex Lipid Emulsion Supplement Prevents Postnatal Deficits in Docosahexaenoic and Arachidonic Acids and Increases Tissue Accretion of Lipophilic Nutrients in Preterm Piglets. JPEN J Parenter Enteral Nutr 2019; 44:69-79. [PMID: 31441521 DOI: 10.1002/jpen.1697] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 07/10/2019] [Accepted: 08/03/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Preterm delivery and current nutrition strategies result in deficiencies of critical long-chain fatty acids (FAs) and lipophilic nutrients, increasing the risk of preterm morbidities. We sought to determine the efficacy of preventing postnatal deficits in FAs and lipophilic nutrients using an enteral concentrated lipid supplement in preterm piglets. METHODS Preterm piglets were fed a baseline diet devoid of arachidonic acid (AA) and docosahexaenoic acid (DHA) and randomized to enteral supplementation as follows: (1) Intralipid (IL), (2) complex lipid supplement 1 (CLS1) with an AA:DHA ratio of 0.25, or (3) CLS2 with an AA:DHA ratio of 1.2. On day 8, plasma and tissue levels of FAs and lipophilic nutrients were measured and ileum histology performed. RESULTS Plasma DHA levels decreased in the IL group by day 2. In contrast, DHA increased by day 2 compared with birth levels in both CLS1 and CLS2 groups. The IL and CLS1 groups demonstrated a continued decline in AA levels during the 8-day protocol, whereas AA levels in the CLS2 group on day 8 were comparable to birth levels. Preserving AA levels in the CLS2 group was associated with greater ileal villus height and muscular layer thickness. Lipophilic nutrients were effectively absorbed in plasma and tissues. CONCLUSIONS Enteral administration of CLS1 and CLS2 demonstrated similar increases in DHA levels compared with birth levels. Only CLS2 maintained AA birth levels. Providing a concentrated complex lipid emulsion with an AA:DHA ratio > 1 is important in preventing postnatal AA deficits.
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Affiliation(s)
- Olajumoke Akinsulire
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - George Perides
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | | | - Joanne Cluette-Brown
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Arthur Nedder
- Animal Resources Children's Hospital, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Elizabeth Pollack
- Animal Resources Children's Hospital, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Pratibha Singh
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Yan Liu
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | | | - Evelyn Obregon
- Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Ece Bicak
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Savanna Kiefer
- Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - William Yakah
- Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Hilda V Gutierrez
- Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Duy T Dao
- Department of Surgery, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Mustafa Vurma
- Abbott Nutrition Research and Development, Abbott Laboratories, Abbott Park, Illinois, USA
| | - Stefan Ehling
- Abbott Nutrition Research and Development, Abbott Laboratories, Abbott Park, Illinois, USA
| | - Douglas Gordon
- Abbott Nutrition Research and Development, Abbott Laboratories, Abbott Park, Illinois, USA
| | - Stephen DeMichele
- Abbott Nutrition Research and Development, Abbott Laboratories, Abbott Park, Illinois, USA
| | - Steven D Freedman
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Division of Translational Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Camilia R Martin
- Department of Neonatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Division of Translational Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
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9
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Di Cagno R, Filannino P, Vincentini O, Cantatore V, Cavoski I, Gobbetti M. Fermented Portulaca oleracea L. Juice: A Novel Functional Beverage with Potential Ameliorating Effects on the Intestinal Inflammation and Epithelial Injury. Nutrients 2019; 11:E248. [PMID: 30678049 PMCID: PMC6412393 DOI: 10.3390/nu11020248] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/21/2019] [Accepted: 01/21/2019] [Indexed: 12/15/2022] Open
Abstract
P. oleracea L. contains high level of nutrients and biologically active compounds. Recently, lactic fermentation has been proposed as a biotechnological option to enrich the profile of biogenic compounds of Portulaca oleracea L. puree. This study investigated the capability of fermentation by selected lactic acid bacteria to enhance the restoring features of Portulaca oleracea juice towards intestinal inflammation and epithelial injury. Lactic acid fermentation markedly increased the total antioxidant capacity of P. oleracea juice, preserved the inherent levels of vitamins C, A, and E, and increased the bioavailability of the level of vitamin B₂ and that of phenolics. The effects of fermented P. oleracea juice on a Caco-2 cell line were investigated using an in vitro model closest to the in vivo conditions. Fermented P. oleracea juice strongly decreased the levels of pro-inflammatory mediators and reactive oxygen species. It also counteracted the disruption of the Caco-2 cell monolayers treated with the inflammatory stimulus. We used a diversified spectrum of lactic acid bacteria species, and some effects appeared to be strains- or species-specific. Fermentation with Lactobacillus kunkeei B7 ensured the best combination for the content of bioactive compounds and the ability to counteract the intestinal inflammation and epithelial injury.
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Affiliation(s)
- Raffaella Di Cagno
- Faculty of Sciences and Technology, Libera Università di Bolzano, 39100 Bolzano, Italy.
| | - Pasquale Filannino
- Department of Soil, Plant and Food Science, University of Bari Aldo Moro, 70126 Bari, Italy.
| | - Olimpia Vincentini
- Unit of Human Nutrition and Health, Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, 00161 Roma, Italy.
| | - Vincenzo Cantatore
- Department of Soil, Plant and Food Science, University of Bari Aldo Moro, 70126 Bari, Italy.
| | - Ivana Cavoski
- CIHEAM-MAIB, Mediterranean Agronomic Institute of Bari, 70010 Valenzano, Bari, Italy.
| | - Marco Gobbetti
- Faculty of Sciences and Technology, Libera Università di Bolzano, 39100 Bolzano, Italy.
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10
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Shirey KA, Sunday ME, Lai W, Patel M, Blanco JCG, Cuttitta F, Vogel SN. Novel role of gastrin releasing peptide-mediated signaling in the host response to influenza infection. Mucosal Immunol 2019; 12:223-231. [PMID: 30327535 PMCID: PMC6301097 DOI: 10.1038/s41385-018-0081-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 07/19/2018] [Accepted: 08/08/2018] [Indexed: 02/04/2023]
Abstract
Gastrin-releasing peptide (GRP) is an evolutionarily well-conserved neuropeptide that was originally recognized for its ability to mediate gastric acid secretion in the gut. More recently, however, GRP has been implicated in pulmonary lung inflammatory diseases including bronchopulmonary dysplasia, chronic obstructive pulmonary disease, emphysema, and others. Antagonizing GRP or its receptor mitigated lethality associated with the onset of viral pneumonia in a well-characterized mouse model of influenza. In mice treated therapeutically with the small-molecule GRP inhibitor, NSC77427, increased survival was accompanied by decreased numbers of GRP-producing pulmonary neuroendocrine cells, improved lung histopathology, and suppressed cytokine gene expression. In addition, in vitro studies in macrophages indicate that GRP synergizes with the prototype TLR4 agonist, lipopolysaccharide, to induce cytokine gene expression. Thus, these findings reveal that GRP is a previously unidentified mediator of influenza-induced inflammatory disease that is a potentially novel target for therapeutic intervention.
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Affiliation(s)
- Kari Ann Shirey
- Dept. of Microbiology and Immunology, Univ. of Maryland, School of Medicine, Baltimore, MD USA 21201
| | - Mary E. Sunday
- Dept. of Pathology, Duke University Medical Center, Durham, NC USA 27710
| | - Wendy Lai
- Dept. of Microbiology and Immunology, Univ. of Maryland, School of Medicine, Baltimore, MD USA 21201
| | - Mira Patel
- Sigmovir Biosystems, Inc., Rockville, MD USA 20850
| | | | - Frank Cuttitta
- Mouse Cancer Genetics Program, National Cancer Institute, NIH, Frederick, MD USA 21702
| | - Stefanie N. Vogel
- Dept. of Microbiology and Immunology, Univ. of Maryland, School of Medicine, Baltimore, MD USA 21201
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11
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Long-chain fatty acid-induced intracellular signaling in GPR120-expressing brush cells at the limiting ridge of the murine stomach. Cell Tissue Res 2018; 376:71-81. [PMID: 30560457 DOI: 10.1007/s00441-018-2972-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/23/2018] [Indexed: 12/29/2022]
Abstract
Brush cells at the gastric groove have been proposed to operate as sensory cells capable of sensing constituents of ingested food. Recent studies have indicated that these cells express GPR120 (also known as FFAR4), the G protein-coupled receptor for long-chain fatty acids (LCFAs). However, functional implications of this receptor in brush cells have remained elusive. Here, we show that a great proportion of brush cells express GPR120. We used phosphorylation of the extracellular signal-regulated kinases 1/2 (ERK1/2) as a readout to monitor brush cell responses to the LCFAs oleic acid and α-linolenic acid. Our results demonstrate that ERK1/2 phosphorylation is increased upon exposure to both fatty acids. Increased ERK1/2 phosphorylation is accompanied by upregulated mRNA and protein levels of cyclooxygenase 2 (COX-2), a key enzyme for prostaglandin biosynthesis. Immunohistochemical experiments confirmed that oleic acid caused ERK1/2 phosphorylation and induced COX-2 expression in brush cells. Our results indicate that LCFA sensing elicits a signaling process in brush cells that may be relevant for a local regulation of gastric functions.
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12
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Golden JM, Escobar OH, Nguyen MVL, Mallicote MU, Kavarian P, Frey MR, Gayer CP. Ursodeoxycholic acid protects against intestinal barrier breakdown by promoting enterocyte migration via EGFR- and COX-2-dependent mechanisms. Am J Physiol Gastrointest Liver Physiol 2018; 315:G259-G271. [PMID: 29672156 PMCID: PMC6139640 DOI: 10.1152/ajpgi.00354.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 01/31/2023]
Abstract
The intestinal barrier is often disrupted in disease states, and intestinal barrier failure leads to sepsis. Ursodeoxycholic acid (UDCA) is a bile acid that may protect the intestinal barrier. We hypothesized that UDCA would protect the intestinal epithelium in injury models. To test this hypothesis, we utilized an in vitro wound-healing assay and a mouse model of intestinal barrier injury. We found that UDCA stimulates intestinal epithelial cell migration in vitro, and this migration was blocked by inhibition of cyclooxygenase 2 (COX-2), epidermal growth factor receptor (EGFR), or ERK. Furthermore, UDCA stimulated both COX-2 induction and EGFR phosphorylation. In vivo UDCA protected the intestinal barrier from LPS-induced injury as measured by FITC dextran leakage into the serum. Using 5-bromo-2'-deoxyuridine and 5-ethynyl-2'-deoxyuridine injections, we found that UDCA stimulated intestinal epithelial cell migration in these animals. These effects were blocked with either administration of Rofecoxib, a COX-2 inhibitor, or in EGFR-dominant negative Velvet mice, wherein UDCA had no effect on LPS-induced injury. Finally, we found increased COX-2 and phosphorylated ERK levels in LPS animals also treated with UDCA. Taken together, these data suggest that UDCA can stimulate intestinal epithelial cell migration and protect against acute intestinal injury via an EGFR- and COX-2-dependent mechanism. UDCA may be an effective treatment to prevent the early onset of gut-origin sepsis. NEW & NOTEWORTHY In this study, we show that the secondary bile acid ursodeoxycholic acid stimulates intestinal epithelial cell migration after cellular injury and also protects the intestinal barrier in an acute rodent injury model, neither of which has been previously reported. These effects are dependent on epidermal growth factor receptor activation and downstream cyclooxygenase 2 upregulation in the small intestine. This provides a potential treatment for acute, gut-origin sepsis as seen in diseases such as necrotizing enterocolitis.
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Affiliation(s)
- Jamie M Golden
- Department of Pediatric Surgery, Children's Hospital Los Angeles , Los Angeles, California
| | - Oswaldo H Escobar
- Department of Pediatric Surgery, Children's Hospital Los Angeles , Los Angeles, California
| | - Michelle V L Nguyen
- Department of Pediatric Surgery, Children's Hospital Los Angeles , Los Angeles, California
| | - Michael U Mallicote
- Department of Pediatric Surgery, Children's Hospital Los Angeles , Los Angeles, California
| | - Patil Kavarian
- Department of Pediatric Surgery, Children's Hospital Los Angeles , Los Angeles, California
| | - Mark R Frey
- Department of Pediatrics and Biochemistry and Molecular Biology, Children's Hospital Los Angeles , Los Angeles, California
- Keck School of Medicine, University of Southern California , Los Angeles, California
| | - Christopher P Gayer
- Department of Pediatric Surgery, Children's Hospital Los Angeles , Los Angeles, California
- Keck School of Medicine, University of Southern California , Los Angeles, California
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13
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Yuan Y, Ding D, Zhang N, Xia Z, Wang J, Yang H, Guo F, Li B. TNF-α induces autophagy through ERK1/2 pathway to regulate apoptosis in neonatal necrotizing enterocolitis model cells IEC-6. Cell Cycle 2018; 17:1390-1402. [PMID: 29950141 DOI: 10.1080/15384101.2018.1482150] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Necrotizing enterocolitis (NEC) is a potentially fatal illness in premature neonates. Tumor necrosis factor-α (TNF-α) and autophagy are associated with the pathogenesis of NEC. This study aimed to explore whether TNF-α might regulate apoptosis in neonatal NEC model cells IEC-6 via regulation of autophagy. NEC rat model was induced by hand feeding and exposure to asphyxia/cold-stress for histologic examination. The NEC in vitro model (IEC-6/NEC cells) was established by stimulating the intestinal epithelial cell line IEC-6 with lipopolysaccharide (LPS, 100 μg/mL) for 3 h to investigate the effects of TNF-α on IEC-6 proliferation and apoptosis. In this study, NEC rats showed decreased proliferating cell nuclear antigen (PCNA) expression, increased TUNEL-positive cells, higher expression of TNF-α, p-ERK1/2, and autophagy-related proteins in rat small intestine compared with their controls. Additionally, the LPS-stimulated IEC-6/NEC cells showed a significantly decreased proliferation and increased apoptosis compared with the control cells. Furthermore, the LPS-stimulated IEC-6/NEC cells exhibited enhanced autophagy level, as evidenced by a dose-dependent increase in Beclin-1 protein expression, LC3II/LC3I ratio and accumulation of MDC-positive autophagic vacuoles. Moreover, inhibition of autophagy by wortmannin or LY294002 significantly abolished the LPS-mediated decreased proliferation and increased apoptosis of IEC-6/NEC cells. Results also showed that inhibition of ERK1/2 pathway using U0126 significantly inhibited TNF-α-induced autophagy. Furthermore, the TNF-α-mediated inhibition of IEC-6 proliferation and promotion of IEC-6 apoptosis was abolished by U0126. Our findings demonstrated that TNF-α might induce autophagy through ERK1/2 pathway to regulate apoptosis in neonatal NEC cells IEC-6. Our study enhances our understanding of neonatal NEC pathogenesis.
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Affiliation(s)
- Yuhang Yuan
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Daokui Ding
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Ning Zhang
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Ziqiang Xia
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Jiaxiang Wang
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Heying Yang
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Fei Guo
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Bing Li
- a Department of Pediatric Surgery , The First Affiliated Hospital of Zhengzhou University , Zhengzhou , China
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14
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Chen W, Zhong H, Wang X, Pang Q, Zhuang J, Hu J, Chen Y, Hu J, Liu J, Tang J. Mig6 reduces inflammatory mediators production by regulating the activation of EGFR in LPS‐induced endotoxemia. J Cell Physiol 2018; 233:6975-6983. [DOI: 10.1002/jcp.26488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/11/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Wenting Chen
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical SciencesSouthern Medical UniversityGuangzhouChina
| | - Hanhui Zhong
- The Department of Anesthesia, Nanfang HospitalSouthern Medical UniversityGuangzhouChina
| | - Xiaofei Wang
- The Department of Anesthesia, Nanfang HospitalSouthern Medical UniversityGuangzhouChina
| | - Qiongni Pang
- The Department of Anesthesia, Nanfang HospitalSouthern Medical UniversityGuangzhouChina
| | - Jinling Zhuang
- The Department of Anesthesia, Nanfang HospitalSouthern Medical UniversityGuangzhouChina
| | - Jian Hu
- Heart, Lung, Blood, and Vascular Medicine InstituteUniversity of PittsburghPittsburgh, Pennsylvania
| | - Yeming Chen
- The Department of AnesthesiaThe Third Affiliated HospitalSouthern Medical UniversityGuangzhouChina
| | - Jijie Hu
- The Department of Orthopaedics and Traumatology, Nanfang HospitalSouthern Medical UniversityGuangzhouChina
| | - Jinghua Liu
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical SciencesSouthern Medical UniversityGuangzhouChina
| | - Jing Tang
- The Department of Anesthesia, Nanfang HospitalSouthern Medical UniversityGuangzhouChina
- The Department of AnesthesiaAffiliated hospital of Guangdong Medical UniversityGuangdongChina
- Guangdong Provincial Key Laboratory of Molecular Oncologic PathologySouthern Medical SciencesGuangzhouChina
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15
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Liu W, Mao L, Ji F, Chen F, Wang S, Xie Y. Icariside II activates EGFR-Akt-Nrf2 signaling and protects osteoblasts from dexamethasone. Oncotarget 2018; 8:2594-2603. [PMID: 27911877 PMCID: PMC5356826 DOI: 10.18632/oncotarget.13732] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 11/21/2016] [Indexed: 12/22/2022] Open
Abstract
The potential effect of icariside II on dexamethasone-induced osteoblast cell damages was evaluated here. In MC3T3-E1 osteoblastic cells and the primary murine osteoblasts, co-treatment with icariside II dramatically attenuated dexamethasone- induced cell death and apoptosis. Icariside II activated Akt signaling, which is required for its actions in osteoblasts. Akt inhibitors (LY294002, perifosine and MK-2206) almost abolished icariside II-induced osteoblast cytoprotection against dexamethasone. Further studies showed that icariside II activated Nrf2 signaling, downstream of Akt, to inhibit dexamethasone-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary osteoblasts. On the other hand, Nrf2 shRNA knockdown inhibited icariside II-induced anti-dexamethasone cytoprotection in MC3T3-E1 cells. Finally, we showed that icariside II induced heparin-binding EGF (HB-EGF) production and EGFR trans-activation in MC3T3-E1 cells. EGFR inhibition, via anti-HB-EGF antibody, EGFR inhibitor AG1478 or EGFR shRNA knockdown, almost blocked icariside II-induced Akt-Nrf2 activation in MC3T3-E1 cells. Collectively, we conclude that icariside II activates EGFR-Akt-Nrf2 signaling and protects osteoblasts from dexamethasone. Icariside II might have translational value for the treatment of dexamethasone-associated osteoporosis/osteonecrosis.
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Affiliation(s)
- Weidong Liu
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Li Mao
- Department of Endocrinology, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Feng Ji
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Fengli Chen
- Clinical Laboratory, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Shouguo Wang
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Yue Xie
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
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16
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Jin X, Zimmers TA, Jiang Y, Milgrom DP, Zhang Z, Koniaris LG. Meloxicam increases epidermal growth factor receptor expression improving survival after hepatic resection in diet-induced obese mice. Surgery 2018; 163:1264-1271. [PMID: 29361369 DOI: 10.1016/j.surg.2017.11.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/08/2017] [Accepted: 11/28/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND Patients with fatty liver have delayed regenerative responses, increased hepatocellular injury, and increased risk for perioperative mortality. Currently, no clinical therapy exists to prevent liver failure or improve regeneration in patients with fatty liver. Previously we demonstrated that obese mice have markedly reduced levels of epidermal growth factor receptor in liver. We sought to identify pharmacologic agents to increase epidermal growth factor receptor expression to improve hepatic regeneration in the setting of fatty liver resection. METHODS Lean (20% calories from fat) and diet-induced obese mice (60% calories from fat) were subjected to 70% or 80% hepatectomy. RESULTS Using the BaseSpace Correlation Engine of deposited gene arrays we identified agents that increased hepatic epidermal growth factor receptor. Meloxicam was identified as inducing epidermal growth factor receptor expression across species. Meloxicam improved hepatic steatosis in diet-induced obese mice both grossly and histologically. Immunohistochemistry and Western blot analysis demonstrated that meloxicam pretreatment of diet-induced obese mice dramatically increased epidermal growth factor receptor protein expression in hepatocytes. After 70% hepatectomy, meloxicam pretreatment ameliorated liver injury and significantly accelerated mitotic rates of hepatocytes in obese mice. Recovery of liver mass was accelerated in obese mice pretreated with meloxicam (by 26% at 24 hours and 38% at 48 hours, respectively). After 80% hepatectomy, survival was dramatically increased with meloxicam treatment. CONCLUSION Low epidermal growth factor receptor expression is a common feature of fatty liver disease. Meloxicam restores epidermal growth factor receptor expression in steatotic hepatocytes. Meloxicam pretreatment may be applied to improve outcome after fatty liver resection or transplantation with steatotic graft.
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Affiliation(s)
- Xiaoling Jin
- Department of Surgery, Thomas Jefferson University School of Medicine, Philadelphia, PA, USA
| | - Teresa A Zimmers
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yanlin Jiang
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Daniel P Milgrom
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Zongxiu Zhang
- Department of Surgery, Thomas Jefferson University School of Medicine, Philadelphia, PA, USA
| | - Leonidas G Koniaris
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
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17
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Valenty LM, Longo CM, Horzempa C, Ambesi A, McKeown-Longo PJ. TLR4 Ligands Selectively Synergize to Induce Expression of IL-8. Adv Wound Care (New Rochelle) 2017; 6:309-319. [PMID: 29062588 DOI: 10.1089/wound.2017.0735] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 05/01/2017] [Indexed: 01/22/2023] Open
Abstract
Objective: Dysfunctional remodeling of the extracellular matrix contributes to the formation of TLR-dependent feed forward loops that drive chronic inflammation. We have previously shown that two Type III domains of Fibronectin, FnEDA and FnIII-1c, cooperate to induce the synergistic release of interleukin 8 (IL-8) from dermal fibroblasts. We now identify steps in the TLR4 pathway where synergy can be demonstrated as well as additional kinases functioning in fibronectin activation of TLR4 signaling. We also evaluate the ligand and cell-type specificity of this synergistic response. Approach: FnEDA, FnIII-1c, and lipopolysaccharide (LPS)-induced genes in fibroblasts were analyzed by a quantitative reverse transcription-polymerase chain reaction (qPCR) and protein was measured by an enzyme-linked immunosorbent assay (ELISA). Kinases functioning in gene expression were identified by using specific inhibitors. Activated TLR4-dependent effector molecules were identified by cell fractionation and Western blot and quantified by image analysis. Results: The addition of FnEDA and FnIII-1c to dermal fibroblasts resulted in a synergistic increase in the expression of IL-8, tumor necrosis factor alpha (TNF-α), and vascular cell adhesion molecule (VCAM-1). Synergy between these domains was detected at the level of nuclear factor kappa-light chain enhancer of activated B cells (NF-κB) and inhibitor of kappa B kinase (IKK) activation. Induction of IL-8 by fibronectin ligands was partially attenuated in the presence of inhibitors to either epidermal growth factor receptor or Src kinases. FnIII-1c also synergized with LPS to induce IL-8 in dermal fibroblasts, whereas the combined effect of FnEDA and LPS on IL-8 synthesis was additive. In contrast, synergistic responses to these ligands were not observed in THP-1 monocytic cells. Innovation: The data suggest that chronic inflammation may be driven by matrix- and pathogen-derived TLR4 ligands that work in synergy to promote an exuberant innate response. Conclusion: The data suggest that the molecular mechanism underlying synergistic responses to TLR4 ligands lies upstream of IKK activation, likely in the molecular composition of the TLR4 receptor complex that assembles in response to each ligand. In addition, synergistic responses to TLR4 activation may be both cell-type and ligand specific.
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Affiliation(s)
- Lauren M. Valenty
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
| | - Christine M. Longo
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
| | - Carol Horzempa
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
| | - Anthony Ambesi
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
| | - Paula J. McKeown-Longo
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
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18
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McKeown-Longo PJ, Higgins PJ. Integration of Canonical and Noncanonical Pathways in TLR4 Signaling: Complex Regulation of the Wound Repair Program. Adv Wound Care (New Rochelle) 2017; 6:320-329. [PMID: 29062589 DOI: 10.1089/wound.2017.0736] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/10/2017] [Indexed: 12/17/2022] Open
Abstract
Significance: Chronic inflammation and maladaptive repair contribute to the development of fibrosis that negatively impacts quality of life and organ function. The toll-like receptor (TLR) system is a critical node in the tissue response to both exogenous (pathogen-associated) and endogenous (damage-associated) molecular pattern factors (PAMPs and DAMPs, respectively). The development of novel TLR ligand-, pathway-, and/or target gene-specific therapeutics may have clinical utility in the management of the exuberant inflammatory/fibrotic tissue response to injury without compromising the host defense to pathogens. Recent Advances: DAMP ligands, released upon wounding, and microbial-derived PAMPs interact with several TLRs, and their various coreceptor partners, engaging downstream pathways that include Src family kinases, the epidermal growth factor receptor, integrins and the tumor suppressor phosphatase and tensin homolog (PTEN). Toll-like receptor 4 (TLR4) activation enhances cellular responses to the potent profibrotic cytokine transforming growth factor-β1 (TGF-β1) by attenuating the expression of receptors that inhibit TGF-β1 signaling. Critical Issues: Common as well as unique pathways may be activated by PAMP and DAMP ligands that bind to the repertoire of TLRs on various cell types. Dissecting mechanisms underlying ligand-dependent engagement of this complex, highly interactive, network will provide for adaptation of new and focused therapies directed to the regulation of pathologically significant profibrotic genes. Inherent in this diversity are therapeutic opportunities to modulate the pathophysiologic consequences of persistent TLR signaling. The recently identified involvement of receptor and nonreceptor kinase pathways in TLR signaling may present novel opportunities for pharmacologic intervention. Future Directions: Clarifying the identity and function of DAMP-activated TLR complexes or ligand-binding partners, as well as their engaged downstream effectors and target genes, are key factors in the eventual design of pathway-specific treatment modalities. Such approaches may be tailored to address the spectrum of TLR-initiated pathologies (including localized and persistent inflammation, maladaptive repair/fibrosis) and, perhaps, even titrated to achieve patient-unique beneficial clinical outcomes.
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Affiliation(s)
- Paula J. McKeown-Longo
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
| | - Paul J. Higgins
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, New York
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19
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Xu X, Wang J, Yang R, Dong Z, Zhang D. Genetic or pharmacologic inhibition of EGFR ameliorates sepsis-induced AKI. Oncotarget 2017; 8:91577-91592. [PMID: 29207668 PMCID: PMC5710948 DOI: 10.18632/oncotarget.21244] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/06/2017] [Indexed: 12/19/2022] Open
Abstract
Despite recent studies have demonstrated that the EGF receptor (EGFR) activation provided a renoprotective role during ischemic and folic acid-induced AKI, the role and regulation mechanism of EGFR in septic AKI remains unclear. Here, gefitinib, a highly selective EGFR inhibitor, abrogated LPS-induced phosphorylation of EGFR, ERK1/2, and STAT3 as well as expression of COX, eNOS, and proinflammatory cytokines in HK-2 cells. In addition, c-Src is an upstream of EGFR signaling pathway and mediates LPS-induced EGFR transactivation. In vivo, either gefitinib or genetic approaches (Wave-2 mutant mice, which have reduced EGFR tyrosine kinase activity) protected against LPS or cecal ligation and puncture (CLP) induced AKI respectively. Interestingly, the beneficial effects of gefitinib or genetic approaches were accompanied by the dephosphorylation of EGFR, ERK1/2, and STAT3, the down regulation of expression of COX, eNOS, macrophage infiltration, proinflammatory cytokines production and the renal cell apoptosis. Furthermore, mRNA array results indicated that gene families involved in cell death, inflammation, proliferation and signal transduction were down regulated in Wave-2 (Wa-2) mice. Take together, these data suggest that EGFR may mediate renal injury by promoting production of inflammatory factors and cell apoptosis. Inhibition of EGFR may have therapeutic potential for AKI during endotoxemia.
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Affiliation(s)
- Xuan Xu
- Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.,Emergency Medicine and Difficult Diseases Institute, Central South University, Changsha, Hunan, People's Republic of China.,Department of Emergency Medicine, Second Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, People's Republic of China
| | - Juan Wang
- Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.,Emergency Medicine and Difficult Diseases Institute, Central South University, Changsha, Hunan, People's Republic of China
| | - Ruhao Yang
- Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.,Emergency Medicine and Difficult Diseases Institute, Central South University, Changsha, Hunan, People's Republic of China
| | - Zheng Dong
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.,Department of Cellular Biology and Anatomy, Medical College of Georgia and Charlie Norwood VA Medical Center, Augusta, Georgia, USA
| | - Dongshan Zhang
- Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.,Emergency Medicine and Difficult Diseases Institute, Central South University, Changsha, Hunan, People's Republic of China.,Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
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20
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Slomiany BL, Slomiany A. Role of LPS-elicited signaling in triggering gastric mucosal inflammatory responses to H. pylori: modulatory effect of ghrelin. Inflammopharmacology 2017; 25:415-429. [PMID: 28516374 DOI: 10.1007/s10787-017-0360-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 05/05/2017] [Indexed: 12/14/2022]
Abstract
Infection with Helicobacter pylori is a primary culprit in the etiology of gastric disease, and its cell-wall lipopolysaccharide (LPS) is recognized as a potent endotoxin responsible for triggering a pattern of the mucosal inflammatory responses. The engagement by the LPS of gastric mucosal Toll-like receptor 4 (TLR4) leads to initiation of signal transduction events characterized by the activation of mitogen-activated protein kinase (MAPK) cascade, induction of phosphoinositide-specific phospholipase C (PLC)/protein kinase C (PKC)/phosphatidylinositol 3-kinase (PI3K) pathway, and up-regulation in Src/Akt. These signaling events in turn exert their influence over H. pylori-elicited excessive generation of NO and PGE2 caused by the disturbances in nitric oxide synthase and cyclooxygenase isozyme systems, increase in epidermal growth factor receptor transactivation, and the induction in matrix metalloproteinase-9 (MMP-9) release. Interestingly, the extent of gastric mucosal inflammatory response to H. pylori is influenced by a peptide hormone, ghrelin, the action of which relays on the growth hormone secretagogue receptor type 1a (GHS-R1a)-mediated mobilization of G-protein dependent transduction pathways. Yet, the signals triggered by TLR-4 activation as well as those arising through GHS-R1a stimulation converge at MAPK and PLC/PKC/PI3K pathways that form a key integration node for proinflammatory signals generated by H. pylori LPS as well as for those involved in modulation of inflammation by ghrelin. Hence, therapeutic targeting these signals' convergence and integration node could provide a novel and attractive opportunities for developing more effective treatments of H. pylori-related gastric disease.
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Affiliation(s)
- B L Slomiany
- Research Center, C855, Rutgers School of Dental Medicine, Rutgers, The State University of New Jersey, 110 Bergen Street, PO Box 1709, Newark, NJ, 07103-2400, USA
| | - A Slomiany
- Research Center, C855, Rutgers School of Dental Medicine, Rutgers, The State University of New Jersey, 110 Bergen Street, PO Box 1709, Newark, NJ, 07103-2400, USA.
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21
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Sukhotnik I, Haj B, Pollak Y, Dorfman T, Bejar J, Matter I. Effect of bowel resection on TLR signaling during intestinal adaptation in a rat model. Surg Endosc 2016; 30:4416-24. [PMID: 26895894 DOI: 10.1007/s00464-016-4760-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 01/11/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND Bacterial overgrowth is common complication of short bowel syndrome (SBS) and is a result of an impaired gut barrier function. Toll-like receptor 4 (TLR4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of bowel resection on TLR4 signaling in intestinal mucosa in a rat model. METHODS Male Sprague-Dawley rats were randomly assigned to one of the two experimental groups of eight rats each: Sham rats underwent bowel transection and re-anastomosis and SBS rats underwent 75 % small bowel resection. Rats were killed on day 14. Bacterial translocation (BT) to mesenteric lymph nodes, liver, portal blood and peripheral blood was determined at the kill. The expression of TLR4, MyD88 and TRAF6 in the intestinal mucosa was determined using real-time PCR, Western blot and immunohistochemistry. RESULTS SBS rats demonstrated a 100 % BT to lymph nodes and to liver (Level I), 80 % translocation to portal blood (Level II) and 60 % translocation to peripheral blood (Level III) at day 7 as well as a 100 % BT to lymph nodes and liver, and 40 % translocation to peripheral blood at day 14. Microarray expression profiling demonstrated that most of the TLR signaling-related genes were up-regulated in resected rats compared to control animals. SBS rats showed a significant increase in TLR4 and TRAF6 mRNA in jejunum and ileum, TLR4 and MyD88 protein expression in jejunum and ileum, and a significant increase in the number of TLR4 and TRAF6 positive cells (immunohistochemistry) compared to sham animals. CONCLUSIONS In a rat model of SBS, elevated intestinal BT is associated with a stimulated TLR4 signaling.
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Affiliation(s)
- Igor Sukhotnik
- Laboratory of Intestinal Adaptation and Recovery, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. .,Department of Pediatric Surgery B, Bnai Zion Medical Center, 47 Golomb St., P.O.B. 4940, 31048, Haifa, Israel.
| | - Bassel Haj
- Laboratory of Intestinal Adaptation and Recovery, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Surgery, Bnai Zion Medical Center, Haifa, Israel
| | - Yulia Pollak
- Laboratory of Intestinal Adaptation and Recovery, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Tatiana Dorfman
- Laboratory of Intestinal Adaptation and Recovery, The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Jacob Bejar
- Department of Pathology, Bnai Zion Medical Center, Haifa, Israel
| | - Ibrahim Matter
- Department of Surgery, Bnai Zion Medical Center, Haifa, Israel
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Slomiany BL, Slomiany A. Helicobacter pylori-induced gastric mucosal TGF-α ectodomain shedding and EGFR transactivation involves Rac1/p38 MAPK-dependent TACE activation. Inflammopharmacology 2015; 24:23-31. [PMID: 26658844 DOI: 10.1007/s10787-015-0254-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 11/11/2015] [Indexed: 01/26/2023]
Abstract
Infection of gastric mucosa by H. pylori triggers a pattern of inflammatory responses characterized by the rise in proinflammatory cytokine production, up-regulation in mitogen-activated protein kinase (MAPK) cascade, and the induction in epidermal growth factor receptor (EGFR) activation. In this study, we report on the role of MAPK/p38 and Rac1 in the regulation of H. pylori LPS-induced TGF-α ectodomain shedding and EGFR transactivation. We show that stimulation of gastric mucosal cells with the LPS, reflected in p38 phosphorylation, guanine nucleotide exchange factor Dock180 activation and the rise in Rac1-GTP level, is accompanied by the activation of membrane-associated metalloprotease, (TACE) also known as ADAM17, responsible for soluble TGF-α release. Further, we reveal that the LPS-induced TGF-α shedding and EGFR transactivation involves the TACE activation through phosphorylation by p38 that requires Rac1 participation. Moreover, we demonstrate that up-regulation in H. pylori LPS-elicited Rac1-GTP membrane translocation plays a pivotal role in recruitment of the activated p38 to the membrane for TACE activation through phosphorylation on Thr(735). Taken together, our findings provide strong evidence as to the essential function of Rac1 in TACE activation, TGF-α ectodomain shedding, and the EGFR transactivation.
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Affiliation(s)
- B L Slomiany
- Research Center, C875, Rutgers School of Dental Medicine, Rutgers, The State University of New Jersey, 110 Bergen Street, PO Box 1709, Newark, NJ, 07103 2400, USA.
| | - A Slomiany
- Research Center, C875, Rutgers School of Dental Medicine, Rutgers, The State University of New Jersey, 110 Bergen Street, PO Box 1709, Newark, NJ, 07103 2400, USA
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Zheng L, Dai YC, Zhang YL, Chen X, Fang CY, Tang ZP. Role of endoplasmic reticulum stress signaling molecule PERK in bowel mucosal injury in ulcerative colitis. Shijie Huaren Xiaohua Zazhi 2015; 23:5493-5498. [DOI: 10.11569/wcjd.v23.i34.5493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Endoplasmic reticulum stress (ERS) is the main focus in the study of the pathogenesis of ulcerative colitis, and it protects and repairs the intestinal epithelial cell (IEC) injury through unfolded protein response (UPR). Protein kinase R-like ER kinase (PERK) is an endoplasmic reticulum-localized type I transmembrane protein, with serine/threonine protein kinase activity. IECs are one of cell populations with the most vigorous metabolism and have abundant endoplasmic reticulum. Early ERS can activate PERK-eIF2 alpha channel and inhibit the synthesis of proteins to protect cells. However, sustained severe ERS promotes cell damage and death, activates nuclear factor-kappa B in IECs, causes the secretion of a variety of inflammatory cytokines, and promotes the occurrence of inflammatory lesions.
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Are EGF and TLR-4 crucial to understanding the link between milk and NEC? Mucosal Immunol 2015; 8:979-81. [PMID: 26037069 DOI: 10.1038/mi.2015.37] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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25
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Erlotinib protects against LPS-induced endotoxicity because TLR4 needs EGFR to signal. Proc Natl Acad Sci U S A 2015. [PMID: 26195767 DOI: 10.1073/pnas.1511794112] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Several components of the canonical pathway of response to lipopolysaccharide (LPS) are required for the EGF-dependent activation of NFκB. Conversely, the ability of Toll-like Receptor 4 (TLR4) to activate NFκB in response to LPS is impaired by down regulating EGF receptor (EGFR) expression or by using the EGFR inhibitor erlotinib. The LYN proto-oncogene (LYN) is required for signaling in both directions. LYN binds to the EGFR upon LPS stimulation, and erlotinib impairs this association. In mice, erlotinib blocks the LPS-induced expression of tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) and ameliorates LPS-induced endotoxity, revealing that EGFR is essential for LPS-induced signaling in vivo.
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Wogonin suppresses inflammatory response and maintains intestinal barrier function via TLR4-MyD88-TAK1-mediated NF-κB pathway in vitro. Inflamm Res 2015; 64:423-31. [PMID: 25917044 DOI: 10.1007/s00011-015-0822-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 04/17/2015] [Indexed: 12/11/2022] Open
Abstract
AIMS AND OBJECTIVE Wogonin has multiple pharmacological effects, including anti-inflammatory effects. Here, we hypothesize that wogonin can protect intestinal barrier function in lipopolysaccharide (LPS)-induced Caco-2 cells, which is an in vitro model of intestinal inflammation. METHODS We measured intestinal barrier function in LPS-induced Caco-2 cells by using transepithelial electrical resistance (TEER) and transport of fluorescent markers. A quantitative (q) RT-PCR and immunofluorescent staining analysis was used to detect the expression of tight junction proteins (claudin-1 and ZO-1) in LPS-induced Caco-2 cells. We measured inflammatory molecules in LPS-induced Caco-2 cells using ELISA and qRT-PCR. In addition, the expression of TLR4, MyD88 and TAK1 and their interaction, and NF-κB activity in LPS-induced Caco-2 cells were investigated by western blot analysis and immune-precipitation. RESULTS We found that exposing Caco-2 cells to wogonin (10 and 50 μM for 24 h) attenuated the LPS-induced changes in TEER and transport of fluorescent markers. In addition, wogonin suppressed LPS-induced down-regulation of tight junction proteins (claudin-1 and ZO-1). Furthermore, LPS-induced up-regulation of inflammatory mediators, including interleukin (IL)-1β, IL-6 and IL-8, cyclooxygenase-2 (COX-2), inducible nitric oxide synthases (iNOS) were reduced after being pre-treated with wogonin. Moreover, wogonin not only inhibited the expression of TLR4, MyD88 and TAK1 and the interaction between these molecules, but also reduced NF-κB translocation to nucleus and its DNA-binding activity in LPS-induced Caco-2 cells. CONCLUSION Our results suggested that pre-treatment with wogonin could attenuate the TLR4-mediated inflammatory response and maintain intestinal barrier function in LPS-induced Caco-2 cells, thus might be a potential therapy for treating IBD.
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27
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Lan KC, Chiu CY, Kao CW, Huang KH, Wang CC, Huang KT, Tsai KS, Sheu ML, Liu SH. Advanced glycation end-products induce apoptosis in pancreatic islet endothelial cells via NF-κB-activated cyclooxygenase-2/prostaglandin E2 up-regulation. PLoS One 2015; 10:e0124418. [PMID: 25898207 PMCID: PMC4405342 DOI: 10.1371/journal.pone.0124418] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 03/13/2015] [Indexed: 12/23/2022] Open
Abstract
Microvascular complications eventually affect nearly all patients with diabetes. Advanced glycation end-products (AGEs) resulting from hyperglycemia are a complex and heterogeneous group of compounds that accumulate in the plasma and tissues in diabetic patients. They are responsible for both endothelial dysfunction and diabetic vasculopathy. The aim of this study was to investigate the cytotoxicity of AGEs on pancreatic islet microvascular endothelial cells. The mechanism underlying the apoptotic effect of AGEs in pancreatic islet endothelial cell line MS1 was explored. The results showed that AGEs significantly decreased MS1 cell viability and induced MS1 cell apoptosis in a dose-dependent manner. AGEs dose-dependently increased the expressions of cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in MS1 cells. Treatment of MS1 cells with AGEs also resulted in increased nuclear factor (NF)-κB-p65 phosphorylation and cyclooxygenase (COX)-2 expression. However, AGEs did not affect the expressions of endoplasmic reticulum (ER) stress-related molecules in MS1 cells. Pretreatment with NS398 (a COX-2 inhibitor) to inhibit prostaglandin E2 (PGE2) production reversed the induction of cleaved caspase-3, cleaved PARP, and MS1 cell viability. Moreover, AGEs significantly increased the receptor for AGEs (RAGE) protein expression in MS1 cells, which could be reversed by RAGE neutralizing antibody. RAGE Neutralizing antibody could also reverse the induction of cleaved caspase-3 and cleaved PARP and decreased cell viability induced by AGEs. These results implicate the involvement of NF-κB-activated COX-2/PGE2 up-regulation in AGEs/RAGE-induced islet endothelial cell apoptosis and cytotoxicity. These findings may provide insight into the pathological processes within the pancreatic islet microvasculature induced by AGEs accumulation.
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Affiliation(s)
- Kuo-Cheng Lan
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chen-Yuan Chiu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chia-Wei Kao
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kuo-How Huang
- Department of Urology, College of Medicine and Hospital, National Taiwan University, Taipei, Taiwan
| | - Ching-Chia Wang
- Department of Pediatrics, College of Medicine and Hospital, National Taiwan University, Taipei, Taiwan
| | - Kuo-Tong Huang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Keh-Sung Tsai
- Departments of Laboratory Medicine, College of Medicine and Hospital, National Taiwan University, Taipei, Taiwan
| | - Meei-Ling Sheu
- Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Shing Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Pediatrics, College of Medicine and Hospital, National Taiwan University, Taipei, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
- * E-mail:
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28
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Xia Q, Hu Q, Wang H, Yang H, Gao F, Ren H, Chen D, Fu C, Zheng L, Zhen X, Ying Z, Wang G. Induction of COX-2-PGE2 synthesis by activation of the MAPK/ERK pathway contributes to neuronal death triggered by TDP-43-depleted microglia. Cell Death Dis 2015; 6:e1702. [PMID: 25811799 PMCID: PMC4385945 DOI: 10.1038/cddis.2015.69] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 01/17/2015] [Accepted: 02/16/2015] [Indexed: 12/12/2022]
Abstract
Neuroinflammation is a striking hallmark of amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Previous studies have shown the contribution of glial cells such as astrocytes in TDP-43-linked ALS. However, the role of microglia in TDP-43-mediated motor neuron degeneration remains poorly understood. In this study, we show that depletion of TDP-43 in microglia, but not in astrocytes, strikingly upregulates cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production through the activation of MAPK/ERK signaling and initiates neurotoxicity. Moreover, we find that administration of celecoxib, a specific COX-2 inhibitor, greatly diminishes the neurotoxicity triggered by TDP-43-depleted microglia. Taken together, our results reveal a previously unrecognized non-cell-autonomous mechanism in TDP-43-mediated neurodegeneration, identifying COX-2-PGE2 as the molecular events of microglia- but not astrocyte-initiated neurotoxicity and identifying celecoxib as a novel potential therapy for TDP-43-linked ALS and possibly other types of ALS.
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Affiliation(s)
- Q Xia
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Q Hu
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - H Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - H Yang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - F Gao
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - H Ren
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - D Chen
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - C Fu
- Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science & Technology of China, Chinese Academy of Sciences, Hefei, Anhui, China
| | - L Zheng
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - X Zhen
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Z Ying
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
- Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - G Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
- Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science & Technology of China, Chinese Academy of Sciences, Hefei, Anhui, China
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29
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Brooke MA, O'Toole EA, Kelsell DP. Exoming into rare skin disease: EGFR deficiency. J Invest Dermatol 2015; 134:2486-2488. [PMID: 25219648 DOI: 10.1038/jid.2014.228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Dermatologists are frequently asked to see patients with pustular eruptions caused by EGFR mAbs or tyrosine kinase inhibitors. In this issue, Campbell et al. describe an infant with severely inflammed skin and bowel and lung disease caused by a homozygous mutation in the EGFR gene. This commentary discusses the power of exome sequencing in disease gene discovery within the rare genodermatoses and the role of aberrant EGFR signaling in a subset of monogenic skin and epithelial syndromes.
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Affiliation(s)
- Matthew A Brooke
- Centre for Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
| | - Edel A O'Toole
- Centre for Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - David P Kelsell
- Centre for Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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30
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Squamosamide derivative FLZ protects retinal pigment epithelium cells from oxidative stress through activation of epidermal growth factor receptor (EGFR)-AKT signaling. Int J Mol Sci 2014; 15:18762-75. [PMID: 25329617 PMCID: PMC4227245 DOI: 10.3390/ijms151018762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/02/2014] [Accepted: 09/11/2014] [Indexed: 12/19/2022] Open
Abstract
Reactive oxygen species (ROS)-mediated retinal pigment epithelium (RPE) cell apoptosis is attributed to age-related macular degeneration (AMD) pathogenesis. FLZ, a novel synthetic squamosamide derivative from a Chinese herb, Annona glabra, has displayed significant cyto-protective activity. In the current study, we explored the pro-survival effect of FLZ in oxidative stressed-RPE cells and studied the underlying signaling mechanisms. Our results showed that FLZ attenuated hydrogen peroxide (H2O2)-induced viability decrease and apoptosis in the RPE cell line (ARPE-19 cells) and in primary mouse RPE cells. Western blotting results showed that FLZ activated AKT signaling in RPE cells. The AKT-specific inhibitor, MK-2206, the phosphoinositide 3-kinase (PI3K)/AKT pan inhibitor, wortmannin, and AKT1-shRNA (short hairpin RNA) depletion almost abolished FLZ-mediated pro-survival/anti-apoptosis activity. We discovered that epidermal growth factor receptor (EGFR) trans-activation mediated FLZ-induced AKT activation and the pro-survival effect in RPE cells, and the anti-apoptosis effect of FLZ against H2O2 was inhibited by the EGFR inhibitor, PD153035, or by EGFR shRNA-knockdown. In conclusion, FLZ protects RPE cells from oxidative stress through activation of EGFR-AKT signaling, and our results suggest that FLZ might have therapeutic values for AMD.
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31
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Lanaya H, Natarajan A, Komposch K, Li L, Amberg N, Chen L, Wculek SK, Hammer M, Zenz R, Peck-Radosavljevic M, Sieghart W, Trauner M, Wang H, Sibilia M. EGFR has a tumour-promoting role in liver macrophages during hepatocellular carcinoma formation. Nat Cell Biol 2014; 16:972-7. [PMID: 25173978 PMCID: PMC4183558 DOI: 10.1038/ncb3031] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 07/18/2014] [Indexed: 12/17/2022]
Abstract
Hepatocellular carcinoma (HCC) is a frequent cancer with limited treatment options and poor prognosis. Tumorigenesis has been linked with macrophage-mediated chronic inflammation and diverse signaling pathways including the Epidermal Growth Factor Receptor (EGFR) pathway. The precise role of EGFR in HCC is unknown, and EGFR-inhibitors have shown disappointing clinical results. Here we discover that EGFR is expressed in liver macrophages in both human HCC and in a mouse HCC model. Mice lacking EGFR in macrophages show impaired hepatocarcinogenesis, whereas mice lacking EGFR in hepatocytes unexpectedly develop more HCC due to increased hepatocyte damage and compensatory proliferation. Mechanistically, following IL-1 stimulation, EGFR is required in liver macrophages to transcriptionally induce IL-6, which triggers hepatocyte proliferation and HCC. Importantly, the presence of EGFR-positive liver macrophages in HCC-patients is associated with poor survival. This study demonstrates a tumor-promoting mechanism for EGFR in non-tumor cells, which could lead to more effective precision medicine strategies.
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Affiliation(s)
- Hanane Lanaya
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Anuradha Natarajan
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Karin Komposch
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Liang Li
- National Center for Liver Cancer. International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute / Hospital, Shanghai, 225 Changhai Road, Shanghai 200438, P.R. China
| | - Nicole Amberg
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Lei Chen
- National Center for Liver Cancer. International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute / Hospital, Shanghai, 225 Changhai Road, Shanghai 200438, P.R. China
| | - Stefanie K Wculek
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Martina Hammer
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Rainer Zenz
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Markus Peck-Radosavljevic
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Wolfgang Sieghart
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Hongyang Wang
- National Center for Liver Cancer. International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute / Hospital, Shanghai, 225 Changhai Road, Shanghai 200438, P.R. China
| | - Maria Sibilia
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
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Saeki T, Inui H, Fujioka S, Fukuda S, Nomura A, Nakamura Y, Park EY, Sato K, Kanamoto R. Staurosporine synergistically potentiates the deoxycholate-mediated induction of COX-2 expression. Physiol Rep 2014; 2:2/8/e12143. [PMID: 25168879 PMCID: PMC4246598 DOI: 10.14814/phy2.12143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Colorectal cancer is a major cause of cancer‐related death in western countries, and thus there is an urgent need to elucidate the mechanism of colorectal tumorigenesis. A diet that is rich in fat increases the risk of colorectal tumorigenesis. Bile acids, which are secreted in response to the ingestion of fat, have been shown to increase the risk of colorectal tumors. The expression of cyclooxygenase (COX)‐2, an inducible isozyme of cyclooxygenase, is induced by bile acids and correlates with the incidence and progression of cancers. In this study, we investigated the signal transduction pathways involved in the bile‐acid‐mediated induction of COX‐2 expression. We found that staurosporine (sts), a potent protein kinase C (PKC) inhibitor, synergistically potentiated the deoxycholate‐mediated induction of COX‐2 expression. Sts did not increase the stabilization of COX‐2 mRNA. The sts‐ and deoxycholate‐mediated synergistic induction of COX‐2 expression was suppressed by a membrane‐permeable Ca2+ chelator, a phosphoinositide 3‐kinase inhibitor, a nuclear factor‐κB pathway inhibitor, and inhibitors of canonical and stress‐inducible mitogen‐activated protein kinase pathways. Inhibition was also observed using PKC inhibitors, suggesting the involvement of certain PKC isozymes (η, θ, ι, ζ, or μ). Our results indicate that sts exerts its potentiating effects via the phosphorylation of p38. However, the effects of anisomycin did not mimic those of sts, indicating that although p38 activation is required, it does not enhance deoxycholate‐induced COX‐2 expression. We conclude that staurosporine synergistically enhances deoxycholate‐induced COX‐2 expression in RCM‐1 colon cancer cells. e12143 The expression of COX‐2, an inducible isozyme of cyclooxygenase, correlates with the incidence and progression of cancers, and bile acids have been shown to induce COX‐2 expression. We investigated the signal transduction pathways involved in the bile‐acid‐mediated induction of COX‐2 expression, and we found that staurosporine, a potent PKC inhibitor, synergistically potentiated the deoxycholate‐mediated induction of COX‐2 expression. Staurosporine exerted its potentiating effects via the phosphorylation of p38, and the involvement of certain PKC isozymes was suggested.
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Affiliation(s)
- Tohru Saeki
- Laboratory of Molecular Nutrition, Kyoto Prefectural University, Kyoto, Japan
| | - Haruka Inui
- Laboratory of Molecular Nutrition, Kyoto Prefectural University, Kyoto, Japan
| | - Saya Fujioka
- Laboratory of Molecular Nutrition, Kyoto Prefectural University, Kyoto, Japan
| | - Suguru Fukuda
- Laboratory of Molecular Nutrition, Kyoto Prefectural University, Kyoto, Japan
| | - Ayumi Nomura
- Laboratory of Molecular Nutrition, Kyoto Prefectural University, Kyoto, Japan
| | - Yasushi Nakamura
- Laboratory of Food Science, Kyoto Prefectural University, Kyoto, Japan
| | - Eun Young Park
- Laboratory of Food Science, Kyoto Prefectural University, Kyoto, Japan
| | - Kenji Sato
- Laboratory of Food Science, Kyoto Prefectural University, Kyoto, Japan
| | - Ryuhei Kanamoto
- Laboratory of Molecular Nutrition, Kyoto Prefectural University, Kyoto, Japan
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Smith JA, Stallons LJ, Schnellmann RG. Renal cortical hexokinase and pentose phosphate pathway activation through the EGFR/Akt signaling pathway in endotoxin-induced acute kidney injury. Am J Physiol Renal Physiol 2014; 307:F435-44. [PMID: 24990892 DOI: 10.1152/ajprenal.00271.2014] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
While disruption of energy production is an important contributor to renal injury, metabolic alterations in sepsis-induced AKI remain understudied. We assessed changes in renal cortical glycolytic metabolism in a mouse model of sepsis-induced AKI. A specific and rapid increase in hexokinase (HK) activity (∼2-fold) was observed 3 h after LPS exposure and maintained up to 18 h, in association with a decline in renal function as measured by blood urea nitrogen (BUN). LPS-induced HK activation occurred independently of HK isoform expression or mitochondrial localization. No other changes in glycolytic enzymes were observed. LPS-mediated HK activation was not sufficient to increase glycolytic flux as indicated by reduced or unchanged pyruvate and lactate levels in the renal cortex. LPS-induced HK activation was associated with increased glucose-6-phosphate dehydrogenase activity but not glycogen production. Mechanistically, LPS-induced HK activation was attenuated by pharmacological inhibitors of the EGF receptor (EGFR) and Akt, indicating that EGFR/phosphatidylinositol 3-kinase/Akt signaling is responsible. Our findings reveal LPS rapidly increases renal cortical HK activity in an EGFR- and Akt-dependent manner and that HK activation is linked to increased pentose phosphate pathway activity.
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Affiliation(s)
- Joshua A Smith
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina; and
| | - L Jay Stallons
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina; and
| | - Rick G Schnellmann
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina; and Ralph H. Johnson Veterans Administration Medical Center, Charleston, South Carolina
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Tyrosine phosphorylation in Toll-like receptor signaling. Cytokine Growth Factor Rev 2014; 25:533-41. [PMID: 25022196 DOI: 10.1016/j.cytogfr.2014.06.002] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 06/16/2014] [Indexed: 12/28/2022]
Abstract
There is a wealth of knowledge about how different Ser/Thr protein kinases participate in Toll-like receptor (TLR) signaling. In many cases, we know the identities of the Ser/Thr residues of various components of the TLR-signaling pathways that are phosphorylated, the functional consequences of the phosphorylation and the responsible protein kinases. In contrast, the analysis of Tyr-phosphorylation of TLRs and their signaling proteins is currently incomplete, because several existing analyses are not systematic or they do not rely on robust experimental data. Nevertheless, it is clear that many TLRs require, for signaling, ligand-dependent phosphorylation of specific Tyr residues in their cytoplasmic domains; the list includes TLR2, TLR3, TLR4, TLR5, TLR8 and TLR9. In this article, we discuss the current status of knowledge of the effect of Tyr-phosphorylation of TLRs and their signaling proteins on their biochemical and biological functions, the possible identities of the relevant protein tyrosine kinases (PTKs) and the nature of regulations of PTK-mediated activation of TLR signaling pathways.
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Lipopolysaccharide differentially modulates expression of cytokines and cyclooxygenases in dorsal root ganglion cells via Toll-like receptor-4 dependent pathways. Neuroscience 2014; 267:241-51. [DOI: 10.1016/j.neuroscience.2014.02.041] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 11/19/2022]
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Gao M, Zhan YQ, Yu M, Ge CH, Li CY, Zhang JH, Wang XH, Ge ZQ, Yang XM. Hepassocin activates the EGFR/ERK cascade and induces proliferation of L02 cells through the Src-dependent pathway. Cell Signal 2014; 26:2161-6. [PMID: 24768768 DOI: 10.1016/j.cellsig.2014.04.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/11/2014] [Indexed: 12/26/2022]
Abstract
Hepassocin (HPS) is a secreted protein with mitogenic activity on primary hepatocytes and protects hepatocytes from chemically-induced injury. Our previous studies showed that HPS stimulates proliferation of hepatocytes in an ERK pathway-dependent manner. However, the molecular mechanism of HPS-induced activation of the ERK pathway remains unclear. In this study, we found that HPS induced the phosphorylation of the epidermal growth factor receptor (EGFR) in the human L02 hepatocyte cell line, and this event was concomitant with the activation of the non-receptor tyrosine kinase Src. Specific inhibition of EGFR kinase activity by gefitinib or down-regulation of EGFR by specific EGFR siRNAs prevented HPS-induced activation of the ERK pathway and proliferation of L02 cells. Furthermore, inhibition of Src activity significantly blocked HPS-induced activation of the EGFR, which was suggestive of a ligand-independent transactivation mechanism of EGFR itself as well as ERK phosphorylation and proliferation of L02 cells. These results indicate that EGFR plays an important role in the mitogenic signaling induced by HPS in L02 cell lines and may further stimulate research on the role of HPS in hepatocytes within biological processes in human health and disease.
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Affiliation(s)
- Ming Gao
- Tianjin University, Department of Pharmaceutical Engineering, Tianjin 300072, China; Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Yi-Qun Zhan
- Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China
| | - Miao Yu
- Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China
| | - Chang-Hui Ge
- Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China
| | - Chang-Yan Li
- Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China
| | - Jian-Hong Zhang
- Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China
| | - Xiao-Hui Wang
- Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China
| | - Zhi-Qiang Ge
- Tianjin University, Department of Pharmaceutical Engineering, Tianjin 300072, China
| | - Xiao-Ming Yang
- Tianjin University, Department of Pharmaceutical Engineering, Tianjin 300072, China; Beijing Institute of Radiation Medicine, Beijing 100850, China; State Key Laboratory of Proteomics, Beijing 100850, China.
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O’Sullivan MJ, Hirota N, Martin JG. Sphingosine 1-phosphate (S1P) induced interleukin-8 (IL-8) release is mediated by S1P receptor 2 and nuclear factor κB in BEAS-2B cells. PLoS One 2014; 9:e95566. [PMID: 24743449 PMCID: PMC3990666 DOI: 10.1371/journal.pone.0095566] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/27/2014] [Indexed: 11/18/2022] Open
Abstract
The airway epithelium may release pro-inflammatory cytokines and chemokines in the asthmatic airway. Sphingosine 1-phosphate (S1P) is a bioactive lipid, increased in the airways of asthmatics, that may trigger the release of the potent neutrophil chemoattractant Interleukin-8 (IL-8) by epithelial cells. S1P is a ligand for 5 G protein-coupled receptors, S1PR1-5. We wished to explore the mechanisms of S1P induced IL-8 secretion with regard to the receptor(s) and downstream signaling events involved. Our results indicate that S1P induced IL-8 release is mediated by S1PR2 and the transcription factor NF-κB. Since the Epidermal Growth Factor Receptor (EGFR) and reactive oxygen species (ROS) have been implicated in IL-8 release in response to activation of other G protein-coupled receptors, we examined their importance in S1P induced IL-8 release and established that they are not involved. This study reveals S1PR2 and NF-κB as potential therapeutic targets in neutrophilic airway diseases such as severe asthma.
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Affiliation(s)
- Michael J. O’Sullivan
- Meakins-Christie Laboratories, Department of Medicine, McGill University and McGill University Health Centre Research Institute, Montréal, Canada
| | - Nobuaki Hirota
- Meakins-Christie Laboratories, Department of Medicine, McGill University and McGill University Health Centre Research Institute, Montréal, Canada
| | - James G. Martin
- Meakins-Christie Laboratories, Department of Medicine, McGill University and McGill University Health Centre Research Institute, Montréal, Canada
- * E-mail:
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Fan JB, Liu W, Yuan K, Zhu XH, Xu DW, Chen JJ, Cui ZM. EGFR trans-activation mediates pleiotrophin-induced activation of Akt and Erk in cultured osteoblasts. Biochem Biophys Res Commun 2014; 447:425-30. [PMID: 24727451 DOI: 10.1016/j.bbrc.2014.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/02/2014] [Indexed: 12/28/2022]
Abstract
Pleiotrophin (Ptn) plays an important role in bone growth through regulating osteoblasts' functions. The underlying signaling mechanisms are not fully understood. In the current study, we found that Ptn induced heparin-binding epidermal growth factor (HB-EGF) release to trans-activate EGF-receptor (EGFR) in both primary osteoblasts and osteoblast-like MC3T3-E1 cells. Meanwhile, Ptn activated Akt and Erk signalings in cultured osteoblasts. The EGFR inhibitor AG1478 as well as the monoclonal antibody against HB-EGF (anti-HB-EGF) significantly inhibited Ptn-induced EGFR activation and Akt and Erk phosphorylations in MC3T3-E1 cells and primary osteoblasts. Further, EGFR siRNA depletion or dominant negative mutation suppressed also Akt and Erk activation in MC3T3-E1 cells. Finally, we observed that Ptn increased alkaline phosphatase (ALP) activity and inhibited dexamethasone (Dex)-induced cell death in both MC3T3-E1 cells and primary osteoblasts, such effects were alleviated by AG1478 or anti-HB-EGF. Together, these results suggest that Ptn-induced Akt/Erk activation and some of its pleiotropic functions are mediated by EGFR trans-activation in cultured osteoblasts.
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Affiliation(s)
- Jian-Bo Fan
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Wei Liu
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Kun Yuan
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Xin-Hui Zhu
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Da-Wei Xu
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Jia-Jia Chen
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Zhi-Ming Cui
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China.
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Zhang F, Li X, Xu X, Cai D, Zhang J. Relationship between the pH of enema solutions and intestinal damage in rabbits. Biol Res Nurs 2014; 17:78-86. [PMID: 25504953 DOI: 10.1177/1099800414527154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mechanical enemas can lead to intestinal mucosal injuries and bowel barrier damage, presenting as electrolyte disturbances and functional intestinal disorders. Most researchers believe that the mechanism of injury is related to osmolality, volume and temperature of the solution, infusion pressure, and the composition of the enema tube. We hypothesized that the pH of the enema solution may also contribute to intestinal damage. We administered enema solutions--normal saline, soapsuds, or vinegar (neutral, alkaline, or acidic solutions, respectively)--to three groups of rabbits (n = 20 per group). The solutions were standardized for volume and temperature and the soapsuds and vinegar solutions were adjusted to be isotonic with normal saline or deionized water. We also included a control group (n = 20) in which the enema tubes were inserted but no solution was administered. We biopsied 3 sites (rectum and distal and proximal colon). Damage to intestinal mucosa was observed by light microscopy and transmission electron microscopy. In order to explore the detection of damage using noninvasive methods, cyclooxygenase (COX)-2 gene expression was measured in the exfoliated cells gathered from postenema defecation. Epithelial loss, inflammatory reaction, and cellular microstructure damage was increased in the vinegar and soapsuds groups. Also, exfoliated cells in these groups had higher COX-2 expression than the normal saline group. The acidic and alkaline enema solutions thus caused more severe damage to the intestinal mucosa compared to the neutral liquid, supporting our hypothesis. Further, the detection of COX-2 expression shows promise as a noninvasive method for estimating enema-induced damage.
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Affiliation(s)
- Feng Zhang
- School of Nursing, Nantong University, Nantong City, Jiangsu Province, China
| | - Xia Li
- School of Nursing, Nantong University, Nantong City, Jiangsu Province, China
| | - Xujuan Xu
- Affiliated hospital of Nantong University, Nantong City, Jiangsu Province, China
| | - Duanying Cai
- School of Nursing, Nantong University, Nantong City, Jiangsu Province, China
| | - Jianguo Zhang
- Affiliated hospital of Nantong University, Nantong City, Jiangsu Province, China
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Zani A, Cananzi M, Fascetti-Leon F, Lauriti G, Smith VV, Bollini S, Ghionzoli M, D'Arrigo A, Pozzobon M, Piccoli M, Hicks A, Wells J, Siow B, Sebire NJ, Bishop C, Leon A, Atala A, Lythgoe MF, Pierro A, Eaton S, De Coppi P. Amniotic fluid stem cells improve survival and enhance repair of damaged intestine in necrotising enterocolitis via a COX-2 dependent mechanism. Gut 2014; 63:300-9. [PMID: 23525603 DOI: 10.1136/gutjnl-2012-303735] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Necrotising enterocolitis (NEC) remains one of the primary causes of morbidity and mortality in neonates and alternative strategies are needed. Stem cells have become a therapeutic option for other intestinal diseases, which share some features with NEC. We tested the hypothesis that amniotic fluid stem (AFS) cells exerted a beneficial effect in a neonatal rat model of NEC. DESIGN Rats intraperitoneally injected with AFS cells and their controls (bone marrow mesenchymal stem cells, myoblast) were analysed for survival, behaviour, bowel imaging (MRI scan), histology, bowel absorption and motility, immunofluorescence for AFS cell detection, degree of gut inflammation (myeloperoxidase and malondialdehyde), and enterocyte apoptosis and proliferation. RESULTS AFS cells integrated in the bowel wall and improved rat survival and clinical conditions, decreased NEC incidence and macroscopic gut damage, improved intestinal function, decreased bowel inflammation, increased enterocyte proliferation and reduced apoptosis. The beneficial effect was achieved via modulation of stromal cells expressing cyclooxygenase 2 in the lamina propria, as shown by survival studies using selective and non-selective cyclooxygenase 2 inhibitors. Interestingly, AFS cells differentially expressed genes of the Wnt/β-catenin pathway, which regulate intestinal epithelial stem cell function and cell migration and growth factors known to maintain gut epithelial integrity and reduce mucosal injury. CONCLUSIONS We demonstrated here for the first time that AFS cells injected in an established model of NEC improve survival, clinical status, gut structure and function. Understanding the mechanism of this effect may help us to develop new cellular or pharmacological therapies for infants with NEC.
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Affiliation(s)
- Augusto Zani
- Surgery Unit, University College London Institute of Child Health, , London, UK
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Heger M, van Golen RF, Broekgaarden M, Michel MC. The molecular basis for the pharmacokinetics and pharmacodynamics of curcumin and its metabolites in relation to cancer. Pharmacol Rev 2013; 66:222-307. [PMID: 24368738 DOI: 10.1124/pr.110.004044] [Citation(s) in RCA: 361] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This review addresses the oncopharmacological properties of curcumin at the molecular level. First, the interactions between curcumin and its molecular targets are addressed on the basis of curcumin's distinct chemical properties, which include H-bond donating and accepting capacity of the β-dicarbonyl moiety and the phenylic hydroxyl groups, H-bond accepting capacity of the methoxy ethers, multivalent metal and nonmetal cation binding properties, high partition coefficient, rotamerization around multiple C-C bonds, and the ability to act as a Michael acceptor. Next, the in vitro chemical stability of curcumin is elaborated in the context of its susceptibility to photochemical and chemical modification and degradation (e.g., alkaline hydrolysis). Specific modification and degradatory pathways are provided, which mainly entail radical-based intermediates, and the in vitro catabolites are identified. The implications of curcumin's (photo)chemical instability are addressed in light of pharmaceutical curcumin preparations, the use of curcumin analogues, and implementation of nanoparticulate drug delivery systems. Furthermore, the pharmacokinetics of curcumin and its most important degradation products are detailed in light of curcumin's poor bioavailability. Particular emphasis is placed on xenobiotic phase I and II metabolism as well as excretion of curcumin in the intestines (first pass), the liver (second pass), and other organs in addition to the pharmacokinetics of curcumin metabolites and their systemic clearance. Lastly, a summary is provided of the clinical pharmacodynamics of curcumin followed by a detailed account of curcumin's direct molecular targets, whereby the phenotypical/biological changes induced in cancer cells upon completion of the curcumin-triggered signaling cascade(s) are addressed in the framework of the hallmarks of cancer. The direct molecular targets include the ErbB family of receptors, protein kinase C, enzymes involved in prostaglandin synthesis, vitamin D receptor, and DNA.
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Affiliation(s)
- Michal Heger
- Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
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Micheva-Viteva SN, Shou Y, Nowak-Lovato KL, Rector KD, Hong-Geller E. c-KIT signaling is targeted by pathogenic Yersinia to suppress the host immune response. BMC Microbiol 2013; 13:249. [PMID: 24206648 PMCID: PMC3827001 DOI: 10.1186/1471-2180-13-249] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/31/2013] [Indexed: 12/27/2022] Open
Abstract
Background The pathogenic Yersinia species exhibit a primarily extracellular lifestyle through manipulation of host signaling pathways that regulate pro-inflammatory gene expression and cytokine release. To identify host genes that are targeted by Yersinia during the infection process, we performed an RNA interference (RNAi) screen based on recovery of host NF-κB-mediated gene activation in response to TNF-α stimulation upon Y. enterocolitica infection. Results We screened shRNAs against 782 genes in the human kinome and 26 heat shock genes, and identified 19 genes that exhibited ≥40% relative increase in NF-κB reporter gene activity. The identified genes function in multiple cellular processes including MAP and ERK signaling pathways, ion channel activity, and regulation of cell growth. Pre-treatment with small molecule inhibitors specific for the screen hits c-KIT and CKII recovered NF-κB gene activation and/or pro-inflammatory TNF-α cytokine release in multiple cell types, in response to either Y. enterocolitica or Y. pestis infection. Conclusions We demonstrate that pathogenic Yersinia exploits c-KIT signaling in a T3SS-dependent manner to downregulate expression of transcription factors EGR1 and RelA/p65, and pro-inflammatory cytokines. This study is the first major functional genomics RNAi screen to elucidate virulence mechanisms of a pathogen that is primarily dependent on extracellular-directed immunomodulation of host signaling pathways for suppression of host immunity.
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Mucosal loss with increased expression of IL-6, IL-8, and COX-2 in a formula-feeding only neonatal rat model of necrotizing enterocolitis. J Pediatr Surg 2013; 48:2301-7. [PMID: 24210203 DOI: 10.1016/j.jpedsurg.2013.04.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/08/2013] [Accepted: 04/14/2013] [Indexed: 02/06/2023]
Abstract
INTRODUCTION The aim of our study is to establish a reliable neonatal rat model by formula feeding only for evaluation of early surgical intervention on the course of experimental necrotizing enterocolitis (NEC). MATERIAL AND METHODS Newborn Sprague-Dawley rats were divided into 50 breast-fed (group 1) and 38 formula fed (Similac/Esbilac, group 2) animals. The pups were sacrificed on the 4th, 5th, and 6th day of life and the terminal intestine examined for macroscopic and histologic changes as well as cytokine expression. RESULTS The histological mucosal damage was significantly higher of group 2 compared to group 1. The area of the vital mucosa of group 2 was significantly (58.57%, p<0.001) lower compared to group 1 (75.12%). The mRNA expression of the inflammatory cytokines IL-6, IL-8 and COX-2 was significantly 2-, 5- and 10-fold increased in group 2 compared to group 1. DISCUSSION Formula fed newborn rats displayed an inflammatory enterocolitis similar to human NEC. Our study demonstrates a significant loss of mucosa in animals with NEC having increased expression levels of IL-6, IL-8 and COX-2. Mucosal loss appears to be a distinct feature of experimental NEC and has to be correlated with the human disease.
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Abstract
Intestinal epithelial cells were once thought to be inert, non-responsive cells that simply acted as a physical barrier that prevents the contents of the intestinal lumen from accessing the underlying tissue. However, it is now clear that these cells express a full repertoire of Toll- and Nod-like receptors, and that their activation by components of the microbiota is vital for the development of a functional epithelium, maintenance of barrier integrity, and defense against pathogenic organisms. Additionally, mounting evidence suggests that epithelial sensing of bacteria plays a significant role in the management of the numbers and types of microbes present in the gut microbiota via the production of antimicrobial peptides and other microbe-modulatory products. This is a critical process, as it is now becoming apparent that alterations in the composition of the microbiota can predispose an individual to a wide variety of chronic diseases. In this review, we will discuss the bacterial pattern recognition receptors that are known to be expressed by the intestinal epithelium, and how each of them individually contributes to these vital protective functions. Moreover, we will review what is known about the communication between epithelial cells and various classes of underlying leukocytes, and discuss how they interact with the microbiota to form a three-part relationship that maintains homeostasis in the gut.
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Eaton S, Zani A, Pierro A, De Coppi P. Stem cells as a potential therapy for necrotizing enterocolitis. Expert Opin Biol Ther 2013; 13:1683-9. [PMID: 24151874 DOI: 10.1517/14712598.2013.849690] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease of neonates, especially those born prematurely, that remains an important cause of morbidity and mortality. Although current treatments such as inotropes, antibiotics and ventilation are supportive, there is an urgent need for novel therapies that specifically target the affected intestine. AREAS COVERED We briefly introduce the disease and the effects on intestinal epithelia. We provide a brief description of amniotic fluid stem (AFS) cells, and then describe some recent data in which AFS cells were beneficial in an animal model of NEC and a potential mechanism is described. The effects of AFS cells are compared with data on bone marrow mesenchymal stem cells. The potential implications of these findings for therapy are discussed. EXPERT OPINION The current data are promising and demonstrate that stem cells do have an effect in rodent models of NEC. However, the short timescale, limited ability for longitudinal evaluation and uncertain clinical relevance of these models means that there are considerable challenges to be overcome before attempting stem cell therapy in clinical trials. Nevertheless, these data open up novel areas of research into a prevention or therapy for this devastating disease.
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Affiliation(s)
- Simon Eaton
- UCL Institute of Child Health , 30 Guilford Street, London , UK
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Demignot S, Beilstein F, Morel E. Triglyceride-rich lipoproteins and cytosolic lipid droplets in enterocytes: key players in intestinal physiology and metabolic disorders. Biochimie 2013; 96:48-55. [PMID: 23871915 DOI: 10.1016/j.biochi.2013.07.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/08/2013] [Indexed: 02/07/2023]
Abstract
During the post-prandial phase, intestinal triglyceride-rich lipoproteins (TRL) i.e. chylomicrons are the main contributors to the serum lipid level, which is linked to coronary artery diseases. Hypertriglyceridemia can originate from decreased clearance or increased production of TRL. During lipid absorption, enterocytes produce and secrete chylomicrons and transiently store lipid droplets (LDs) in the cytosol. The dynamic fluctuation of triglycerides in cytosolic LDs suggests that they contribute to TRL production and may thus control the length and amplitude of the post-prandial hypertriglyceridemia. In this review, we will describe the recent advances in the characterization of enterocytic LDs. The role of LDs in chylomicron production and secretion as well as potential previously unsuspected functions in the metabolism of vitamins, steroids and prostaglandins and in viral infection will also be discussed.
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Affiliation(s)
- Sylvie Demignot
- Université Pierre et Marie Curie, UMR S 872, Centre de Recherche des Cordeliers, Paris, France; Inserm, U 872, Paris, France; Ecole Pratique des Hautes Etudes, Laboratoire de Pharmacologie Cellulaire et Moléculaire, Paris, France; Université Paris Descartes, UMR S 872, Paris, France; Institut de Cardiométabolisme et Nutrition (ICAN), Paris, France.
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Ochiai S, Furuta D, Sugita K, Taniura H, Fujita N. GPR87 mediates lysophosphatidic acid-induced colony dispersal in A431 cells. Eur J Pharmacol 2013; 715:15-20. [PMID: 23831392 DOI: 10.1016/j.ejphar.2013.06.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 06/06/2013] [Accepted: 06/21/2013] [Indexed: 01/17/2023]
Abstract
We have previously reported that an orphan G protein-coupled receptor GPR87 was activated by lysophosphatidic acid (LPA) and that it induced an increase in the intracellular Ca(2+) levels in the CHO cells genetically engineered to express GPR87-Gα16 fusion protein. Because the Ca(2+) response was blocked by the LPA receptor antagonist Ki16425, GPR87 was suggested to be a putative LPA receptor. However, further studies are required to confirm whether GPR87 is an LPA receptor. A previous study showed that colonies of A431 cells treated with LPA showed rapid and synchronized dissociation. Because A431 cells have been shown to express GPR87, we used these cells to examine whether GPR87 acted as an LPA receptor. When A431 cells were treated with gpr87-specific siRNA, the expression of GPR87 was decreased and LPA-induced colony dispersal was significantly reduced. Treatment of the cells with lpa1 siRNA had an additive effect in decrease in the colony dispersal. Studies on the LPA-mediated signaling pathway in A431 cells indicated that transactivation of the epidermal growth factor receptor (EGFR) by LPA led to cell scattering. PD153035, an inhibitor of tyrosine-kinase of EGFR, and BB94, an inhibitor of metalloprotease which produces a ligand for EGFR, significantly prevented the LPA-induced scattering of A431 cells pretreated with lpa1 or gpr87-siRNA. These results strongly suggested that GPR87 acts as an LPA receptor and induces colony dispersal via the transactivation of EGFR in A431 cells.
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Affiliation(s)
- Shoichi Ochiai
- Laboratory of Pharmacoinformitcs, Graduate School of Ritsumeikan University, and School of Pharmacy, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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Hackam DJ, Good M, Sodhi CP. Mechanisms of gut barrier failure in the pathogenesis of necrotizing enterocolitis: Toll-like receptors throw the switch. Semin Pediatr Surg 2013; 22:76-82. [PMID: 23611610 PMCID: PMC3644853 DOI: 10.1053/j.sempedsurg.2013.01.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Necrotizing enterocolitis (NEC) is the leading cause of death from gastrointestinal causes in premature infants, and its overall survival has not improved in the past three decades. While the precise cause of NEC remains incompletely understood, we and others have shown that a major predisposing factor in the development and propagation of NEC is a breakdown of the intestinal barrier which leads to bacterial translocation and systemic sepsis. In seeking to identify the causes involved, we and others have also determined that activation of the receptor for bacterial endotoxin, namely toll-like receptor 4 (TLR4), is required for the development of intestinal barrier failure leading to NEC. We have also shown that the premature infant is endowed with strategies that can either limit or promote the extent of TLR4 signaling within the gut, which together determine the relative propensity with which NEC develops. In this review, we highlight the evidence for TLR4 signaling in the pathogenesis of NEC through a survey of its effects on gut barrier failure. We identify how TLR4 regulation within the gut can explain the unique susceptibility of the premature infant to the development of NEC, and highlight how strategies to limit the degree of TLR4 signaling can serve as novel therapeutic approaches for this devastating disease.
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Affiliation(s)
- David J. Hackam
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine
| | - Misty Good
- Division of Newborn Medicine, Department of Pediatrics, Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine
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Xu G, Duan Z, Chen G, Nie X, Liu J, Zhang Y, Li Y, Wan C, Jiang J. Role of mitogen-activated protein kinase cascades in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced apoptosis in neuronal pheochromocytoma cells. Hum Exp Toxicol 2013; 32:1278-91. [PMID: 23584357 DOI: 10.1177/0960327113482595] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Mitogen-activated protein kinases (MAPKs) are involved in neuronal death caused by many cytotoxins. Conventional MAPKs consist of three family members: extracellular signal-regulated kinase-1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38. It has been originally shown that ERK1/2 is important for cell survival, whereas JNK and p38 are deemed stress responsive and thus involved in apoptosis. However, information describing the role of MAPKs in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced neurotoxicity is insufficient. The aim of this study was to identify the role of MAPK cascades in TCDD-induced neurotoxicity using differentiated pheochromocytoma (PC12) cells as a model for neuronal cells. Cell viability assay, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and flow cytometry analysis showed that TCDD attenuated cell viability with a dose- and time-dependent manner and significantly induced apoptosis in primary cortical neurons and PC12 cells. Western blot analysis indicated that TCDD markedly activated the expression of ERK1/2, JNK and p38 in TCDD-treated PC12 cells. Furthermore, PD98059 (ERK1/2 inhibitor), SP600125 (JNK inhibitor) and SB202190 (p38 inhibitor) notably blocked the effect of TCDD on cell apoptosis. Based on the findings above, it is concluded that the activation of MAPK signaling pathways may be associated with TCDD-mediated neuronal apoptosis.
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Affiliation(s)
- G Xu
- 1Department of Nutrition and Food Hygiene, School of Public Health, Nantong University, Nantong, Jiangsu, People's Republic of China
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