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Huang K, Pitman M, Oladosu O, Echesabal-Chen J, Vojtech L, Esobi I, Larsen J, Jo H, Stamatikos A. The Impact of MiR-33a-5p Inhibition in Pro-Inflammatory Endothelial Cells. Diseases 2023; 11:88. [PMID: 37489440 PMCID: PMC10366879 DOI: 10.3390/diseases11030088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 07/26/2023] Open
Abstract
Evidence suggests cholesterol accumulation in pro-inflammatory endothelial cells (EC) contributes to triggering atherogenesis and driving atherosclerosis progression. Therefore, inhibiting miR-33a-5p within inflamed endothelium may prevent and treat atherosclerosis by enhancing apoAI-mediated cholesterol efflux by upregulating ABCA1. However, it is not entirely elucidated whether inhibition of miR-33a-5p in pro-inflammatory EC is capable of increasing ABCA1-dependent cholesterol efflux. In our study, we initially transfected LPS-challenged, immortalized mouse aortic EC (iMAEC) with either pAntimiR33a5p plasmid DNA or the control plasmid, pScr. We detected significant increases in both ABCA1 protein expression and apoAI-mediated cholesterol efflux in iMAEC transfected with pAntimiR33a5p when compared to iMAEC transfected with pScr. We subsequently used polymersomes targeting inflamed endothelium to deliver either pAntimiR33a5p or pScr to cultured iMAEC and showed that the polymersomes were selective in targeting pro-inflammatory iMAEC. Moreover, when we exposed LPS-challenged iMAEC to these polymersomes, we observed a significant decrease in miR-33a-5p expression in iMAEC incubated with polymersomes containing pAntimR33a5p versus control iMAEC. We also detected non-significant increases in both ABCA1 protein and apoAI-mediated cholesterol in iMAEC exposed to polymersomes containing pAntimR33a5p when compared to control iMAEC. Based on our results, inhibiting miR-33a-5p in pro-inflammatory EC exhibits atheroprotective effects, and so precisely delivering anti-miR-33a-5p to these cells is a promising anti-atherogenic strategy.
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Affiliation(s)
- Kun Huang
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA
| | - Mark Pitman
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC 29634, USA
| | - Olanrewaju Oladosu
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA
| | - Jing Echesabal-Chen
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA
| | - Lucia Vojtech
- Department of Obstetrics & Gynecology, University of Washington, Seattle, WA 98109, USA
| | - Ikechukwu Esobi
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA
| | - Jessica Larsen
- Department of Chemical and Biomolecular Engineering, Clemson University, Clemson, SC 29634, USA
- Department of Bioengineering, Clemson University, Clemson, SC 29634, USA
| | - Hanjoong Jo
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA
| | - Alexis Stamatikos
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, SC 29634, USA
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2
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Lipopolysaccharide affects energy metabolism and elevates nicotinamide N-methyltransferase level in human aortic endothelial cells (HAEC). Int J Biochem Cell Biol 2022; 151:106292. [PMID: 36038127 DOI: 10.1016/j.biocel.2022.106292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/10/2022] [Accepted: 08/24/2022] [Indexed: 11/21/2022]
Abstract
This study aimed to investigate the putative role of nicotinamide N-methyltransferase in the metabolic response of human aortic endothelial cells. This enzyme catalyses S-adenosylmethionine-mediated methylation of nicotinamide to methylnicotinamide. This reaction is accompanied by the reduction of the intracellular nicotinamide and S-adenosylmethionine content. This may affect NAD+ synthesis and various processes of methylation, including epigenetic modifications of chromatin. Particularly high activity of nicotinamide N-methyltransferase is detected in liver, many neoplasms as well as in various cells in stressful conditions. The elevated nicotinamide N-methyltransferase content was also found in endothelial cells treated with statins. Although the exogenous methylnicotinamide has been postulated to induce a vasodilatory response, the specific metabolic role of nicotinamide N-methyltransferase in vascular endothelium is still unclear. Treatment of endothelial cells with bacterial lipopolysaccharide evokes several metabolic and functional consequences which built a multifaceted physiological response of endothelium to bacterial infection. Among the spectrum of biochemical changes substantially elevated protein level of nicotinamide N-methyltransferase was particularly intriguing. Here it has been shown that silencing of the nicotinamide N-methyltransferase gene influences several changes which are observed in cells treated with lipopolysaccharide. They include altered energy metabolism and rearrangement of the mitochondrial network. A complete explanation of the mechanisms behind the protective consequences of the nicotinamide N-methyltransferase deficiency in cells treated with lipopolysaccharide needs further investigation.
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Jagadeesh N, Belur S, Ballal S, Roy S, Inamdar SR. Cephalosporium curvulum lectin causes mycotic keratitis by initiating infection through MyD88 dependent cellular proliferation and apoptosis in human corneal epithelial cells. Glycoconj J 2021; 38:509-516. [PMID: 34146213 DOI: 10.1007/s10719-021-10004-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/08/2020] [Accepted: 06/02/2021] [Indexed: 11/25/2022]
Abstract
Physiological role of a core fucose specific lectin from Cephalosporium curvulum isolated from mycotic keratitis patient in mediating pathogenesis was reported earlier. CSL has opposite effects on HCECs, at the initiation of infection when lectin concentration is low, CSL induces proinflammatory response and at higher concentration it inhibits growth as the infection progresses. Here we delineate detailed mechanism of opposing effects of CSL by confirming the binding of CSL and anti TLR 2 and 4 antibodies to TLRs 2 and 4 purified from HCECs using Galectin-3 Sepharose 4B column. Further, the expression of signaling proteins were monitored by Western blotting and apoptosis assay. At concentration of 0.3 µg/ml, CSL induced the activation of TLR-2,-4 and adapter protein MyD88. CSL also induced the expression of transcription factors NFkB, C-Jun and proinflammatory cytokines like interleukins -6 and -8 essential in maintaining cell proliferation. In contrast at higher concentrations i.e. 5 µg/ml CSL induces apoptotic effect as evidenced by increase in early and late apoptotic population as demonstrated by Annexin V-PI assay. Western blotting revealed that CSL treated HCECs at higher concentration lead to MyD88 dependent expression of apoptotic proteins like FADD, Caspase -8 and -3. All these results are in line with and substantiate our earlier results that indeed CSL is involved in mediating host pathogen interactions by interacting with cell surface TLRs, activating downstream signaling pathways leading to pathogenesis. Findings are of clinical significance in developing carbohydrate based therapeutic strategy to control infection and the disease.
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Affiliation(s)
| | - Shivakumar Belur
- Department of Studies in Biochemistry, Karnatak University, Dharwad, 580003, India
| | - Suhas Ballal
- Department of Studies in Biochemistry, Karnatak University, Dharwad, 580003, India
| | - Sanhita Roy
- Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| | - Shashikala R Inamdar
- Department of Studies in Biochemistry, Karnatak University, Dharwad, 580003, India.
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Gandhi S, Ravindra K. Toll-Like Receptors in Dermatology, Venereology, and Leprosy. Indian J Dermatol 2021; 66:223. [PMID: 34188292 PMCID: PMC8208254 DOI: 10.4103/ijd.ijd_486_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Toll-like receptors (TLRs) represent a family of Type I transmembrane proteins characterized by an extracellular leucine-rich repeat domain and a cytoplasmic domain. TLRs represent a conserved group of receptors which help the immune system to function properly. Different TLRs are associated with an array of skin diseases. TLR agonists and antagonists have great potential for the treatment of allergic and inflammatory diseases.
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Affiliation(s)
- Sneha Gandhi
- Department of Dermatology, Venereology and Leprosy, GIMS, Gulbarga, Karnataka, India
| | - K Ravindra
- Department of Dermatology, Venereology and Leprosy, JJMMC, Davangere, Karnataka, India
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Aria H, Kalani M, Hodjati H, Doroudchi M. Different cytokine patterns induced by Helicobacter pylori and Lactobacillus acidophilus extracts in PBMCs of patients with abdominal aortic aneurysm. Comp Immunol Microbiol Infect Dis 2020; 70:101449. [PMID: 32126431 DOI: 10.1016/j.cimid.2020.101449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 01/22/2020] [Accepted: 02/11/2020] [Indexed: 12/28/2022]
Abstract
Abdominal aortic aneurysm (AAA) is a degenerative inflammatory disease with unknown etiology. AAA is characterized by abdominal aortic dilatation more than 3 cm and is often asymptomatic, but the rupture of aneurysm can lead to death. Age, smoking and male sex are major predisposing factors of AAA. This study compares the effect of Helicobacter (H.) pylori and Lactobacillus (L.) acidophilus on the cytokine profile of PBMCs of 5 men with abdominal aortic aneurysm (AAA) and 5 men with normal/insignificant angiography, CT-Scan and ultrasonography results in the single-culture and in the co-culture with HUVECs. IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17A, IL-17 F, IL-21, IL-22, IFN-γ and TNF-α were measured in culture supernatants using a commercial fluorescent-labeled-bead assay. In general, CagA+ H. pylori-extract induced higher production of IFN-γ, IL-13 and IL-21 by PBMCs. Treatment of patients' PBMCs with CagA+H. pylori-extract induced Th2 cytokines while treatment of controls' PBMCs with CagA+H. pylori-extract increased Th1 cytokines. In the co-culture, however, patients' PBMCs produced Th1 cytokines irrespective of extract treatment, while controls' PBMCs produced Th2 cytokines and decreased IL-10. CagA+ H. pylori- as well as L. acidophilus-extract induced higher levels of IL-9 by controls' PBMCs in co-culture with HUVECs than patients (P = 0.05 and P = 0.01). The cytokine pattern of PBMCs induced by CagA+ H. pylori- and L. acidophilus-extracts in the co-culture with HUVECs shows differences in AAA patients and in comparison to controls. Decreased secretion of IL-9, IL-21 and IL-22 by PBMCs of patients treated with CagA+ H. pylori extract in co-culture, as opposed to non-AAA controls may indicate the active role ECs play in AAA. Simultaneous production of IL-10 and Th1 cytokines in patients and pronounced Th2 cytokines in controls in response to both bacteria may point to the inherent differences between patients and controls, which need further investigation.
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Affiliation(s)
- Hamid Aria
- Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mehdi Kalani
- Prof. Alborzi Clinical Microbiology Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hossein Hodjati
- Department of Vascular Surgery, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mehrnoosh Doroudchi
- Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
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6
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Qu C, Sun J, Xu Q, Lv X, Yang W, Wang F, Wang Y, Yi Q, Jia Z, Wang L, Song L. An inhibitor of apoptosis protein (EsIAP1) from Chinese mitten crab Eriocheir sinensis regulates apoptosis through inhibiting the activity of EsCaspase-3/7-1. Sci Rep 2019; 9:20421. [PMID: 31892728 PMCID: PMC6938513 DOI: 10.1038/s41598-019-56971-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/19/2019] [Indexed: 01/13/2023] Open
Abstract
Inhibitor of apoptosis proteins (IAPs) maintain the balance between cell proliferation and cell death by inhibiting caspase activities and mediating immune responses. In the present study, a homolog of IAP (designated as EsIAP1) was identified from Chinese mitten crab Eriocheir sinensis. EsIAP1 consisted of 451 amino acids containing two baculoviral IAP repeat (BIR) domains with the conserved Cx2 Cx6 Wx3 Dx5 Hx6 C motifs. EsIAP1 mRNA was expressed in various tissues and its expression level in hemocytes increased significantly (p < 0.01) at 12–48 h after lipopolysaccharide stimulation. In the hemocytes, EsIAP1 protein was mainly distributed in the cytoplasm. The hydrolytic activity of recombinant EsCaspase-3/7-1 against the substrate Ac-DEVD-pNA decreased after incubation with rEsIAP1. Moreover, rEsIAP1 could directly combine with rEsCaspase-3/7-1 in vitro. After EsIAP1 was interfered by dsRNA, the mRNA expression and the hydrolytic activity of EsCaspase-3/7-1 increased significantly, which was 2.26-fold (p < 0.05) and 1.71-fold (p < 0.05) compared to that in the dsGFP group, respectively. These results collectively demonstrated that EsIAP1 might play an important role in apoptosis pathway by regulating the activity of EsCaspase-3/7-1 in E. sinensis.
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Affiliation(s)
- Chen Qu
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China
| | - Jiejie Sun
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China
| | - Qingsong Xu
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China.,Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Xiaojing Lv
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China.,Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China.,Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China.,Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Wen Yang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China
| | - Feifei Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China
| | - Ying Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China
| | - Qilin Yi
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China.,Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China.,Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Zhihao Jia
- Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China.,Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China.,Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China.,Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China. .,Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China. .,Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China. .,Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China.
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Kim M, Park SH, Park JS, Kim HJ, Han BW. Crystal Structure of Human EOLA1 Implies Its Possibility of RNA Binding. MOLECULES (BASEL, SWITZERLAND) 2019; 24:molecules24193529. [PMID: 31569543 PMCID: PMC6803910 DOI: 10.3390/molecules24193529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 01/07/2023]
Abstract
Human endothelial-overexpressed lipopolysaccharide-associated factor 1 (EOLA1) has been suggested to regulate inflammatory responses in endothelial cells by controlling expression of proteins, interleukin-6 and vascular cell adhesion molecule-1, and by preventing apoptosis. To elucidate the structural basis of the EOLA1 function, we determined its crystal structure at 1.71 Å resolution and found that EOLA1 is structurally similar to an activating signal cointegrator-1 homology (ASCH) domain with a characteristic β-barrel fold surrounded by α-helices. Despite its low sequence identity with other ASCH domains, EOLA1 retains a conserved 'GxKxxExR' motif in its cavity structure. The cavity harbors aromatic and polar residues, which are speculated to accommodate nucleotide molecules as do YT521-B homology (YTH) proteins. Additionally, EOLA1 exhibits a positively charged cleft, similar to those observed in YTH proteins and the ASCH protein from Zymomonas mobilis that exerts ribonuclease activity. This implies that the positively charged cleft in EOLA1 could stabilize the binding of RNA molecules. Taken together, we suggest that EOLA1 controls protein expression through RNA binding to play protective roles against endothelial cell injuries resulting from lipopolysaccharide (LPS)-induced inflammation responses.
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Affiliation(s)
- Minju Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
| | - Sang Ho Park
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Joon Sung Park
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
| | - Hyun-Jung Kim
- College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Korea.
| | - Byung Woo Han
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
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Shen L, Hu Y, Lou J, Yin S, Wang W, Wang Y, Xia Y, Wu W. CircRNA‑0044073 is upregulated in atherosclerosis and increases the proliferation and invasion of cells by targeting miR‑107. Mol Med Rep 2019; 19:3923-3932. [PMID: 30864721 DOI: 10.3892/mmr.2019.10011] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 09/13/2018] [Indexed: 11/05/2022] Open
Abstract
Circular RNAs (circRNAs) are endogenous non‑coding RNAs implicated in atherosclerosis. The aim of the present study was to explore the function of circRNA‑0044073 in atherosclerosis. Reverse transcription quantitative polymerase chain reaction assays were used to measure the expression levels of circRNA‑0044073, microRNA (miRNA/miR)‑107, janus kinase 1 (JAK1), signal transducer and activator of transcription 3 (STAT3), B‑cell lymphoma 2 (Bcl‑2) and v‑myc avian myelocytomatosis viral oncogene homolog (c‑myc) in in blood cells from patients with atherosclerosis. RNA pull‑down and luciferase reporter assays were then used to determine the association between circRNA and miR expression, and miR and gene expression, respectively. Matrigel invasion assay and flow cytometry were used to analyze cell invasion and cell cycle. Western blot analysis and ELISA were used to evaluate the expression levels of proteins. It was identified that the expression of circRNA‑0044073 was upregulated and the expression of miR‑107 was downregulated in atherosclerotic blood cells. Overexpression of circRNA‑0044073 promoted the proliferation of human vascular smooth muscle cells (HUVSMCs) and human vascular endothelial cells (HUVECs), while overexpression of miR‑107 inhibited their proliferation. In addition, circRNA‑0044073 suppressed the levels of miR‑107 via a sponge mechanism. Lipopolysaccharide (LPS) affected the proliferation of HUVSMCs and HUVECs, and also resulted in changes in circRNA‑0044073 expression levels. CircRNA‑0044073 promoted the proliferation and invasion of HUVSMCs and HUVECs in spite of the opposite effect observed with LPS treatment. The JAK/STAT signaling pathway was activated in patients with atherosclerosis. CircRNA‑0044073 favored the activation of the JAK/STAT signaling pathway and inflammation in HUVSMCs and HUVECs. These data indicate that circRNA‑0044073 is upregulated in atherosclerosis and promotes the proliferation and invasion of cells by targeting miR‑107 and activating the JAK/STAT signaling pathway, potentially offering a target for novel treatment strategies against atherosclerosis.
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Affiliation(s)
- Lin Shen
- Department of Geriatrics, Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qi‑Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Yanyan Hu
- Department of Geriatrics, Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qi‑Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Jianwei Lou
- Department of Neurology, Qi‑Lu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Sen Yin
- Department of Neurology, Qi‑Lu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Weiling Wang
- Department of Geriatrics, Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qi‑Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Yuanyan Wang
- Department of Geriatrics, Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qi‑Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Yong Xia
- Department of Geriatrics, Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qi‑Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Wei Wu
- Department of Neurology, Qi‑Lu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, Shandong 250012, P.R. China
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9
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Li C, Yan S, He W, Yang S, Sun J, Gu N. Real-time Temperature Measurements of HMEC-1 Cells during Inflammation Production and Repair detected by Wireless Thermometry. IEEE Trans Biomed Eng 2018; 66:1898-1904. [PMID: 30418879 DOI: 10.1109/tbme.2018.2880740] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Cell inflammation process is reflected through real-time in situ cellular temperature changes. METHODS A wireless thermometry system for in situ cellular temperature measurements was used in an incubator to detect the HMEC-1 cellular temperature under lipopolysaccharide inflammation production and norepinephrine for inflammation repair. Combining the changes in cell viability, inflammatory factor levels and ATP content caused by different lipopolysaccharide or norepinephrine doses, an obvious inflammatory response and repair effect was obtained. Temperature variations were correlated with ATP content. RESULTS An obvious inflammatory response with a lipopolysaccharide concentration of 0.1 mg/L and an optimal repair effect with 1 μM norepinephrine were obtained. The relationship between temperature changes and ATP content were quite different during the production of inflammation in HMEC-1 cells, having an approximately linear relationship, while under conditions of inflammation repair in HMEC-1 cells, there was an obvious nonlinear relationship. CONCLUSION During cell damage, cell thermogenesis has a linear correlation with intracellular energy. While during cell repair, there is a gradual saturation relationship between the temperature (small range) and ATP, which may be because the thermogenesis capacity of the cell is enhanced compared to conditions during cell energy storage. Additionally, there is an optimal drug concentration for cell action during cell injury and cell repair, which is not dose-dependent. SIGNIFICANCE Whether in inflammation production or treatment, there is an optimal drug concentration. The relationship between cell thermogenesis and intracellular energy reserves is related to cell processes. Quick analysis of the energy changes in different physiological process can be realized.
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10
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Samanta S, Zhou Z, Rajasingh S, Panda A, Sampath V, Rajasingh J. DNMT and HDAC inhibitors together abrogate endotoxemia mediated macrophage death by STAT3-JMJD3 signaling. Int J Biochem Cell Biol 2018; 102:117-127. [PMID: 30010012 PMCID: PMC6309960 DOI: 10.1016/j.biocel.2018.07.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/30/2018] [Accepted: 07/11/2018] [Indexed: 12/11/2022]
Abstract
Acute lung injury (ALI) is a common complication of sepsis that often leads to fatal lung disease without effective therapies. It is known that bone marrow derived macrophages are important in resolving the inflammation and maintaining tissue homeostasis. Here, we hypothesize that treatment in combination of DNA methyl transferase inhibitor (DNMTi) 5-Aza 2-deoxycytidine (Aza) and histone deacetylase inhibitor (HDACi) Trichostatin A (TSA) mitigates the inflammation induced pyroptosis and apoptosis during endotoxemia induced ALI. To test this hypothesis, the mice challenged with a sublethal dose of LPS followed by one-hour post-treatment with a single dose of Aza and TSA intraperitoneally showed a substantial attenuation of apoptosis and inflammation. Importantly, we observed significant changes in the mitochondrial membrane structure, and lower levels of DNA fragmentation, reduced expression of apoptotic and pyroptotic genes both transcriptionally and translationally in LPS induced BMDMs treated by a combination of Aza and TSA than in LPS-induced BMDMs treated with either drug alone. The protection was mediated by an inhibition of JNK-ERK and STAT3-JMJD3 activated pathways. Thus, targeting these important signaling pathways with the combination of Aza and TSA would be a good treatment modality for ALI.
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Affiliation(s)
- Saheli Samanta
- Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Zhigang Zhou
- Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA; Department of Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, 201620, China
| | - Sheeja Rajasingh
- Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Arunima Panda
- Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Venkatesh Sampath
- Department of Pediatrics, Division of Neonatology, Children's Mercy Hospital, Kansas City, MO, USA
| | - Johnson Rajasingh
- Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS, 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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11
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ABDUL Y, WARD R, DONG G, ERGUL A. Lipopolysaccharide-Induced Necroptosis of Brain Microvascular Endothelial Cells Can Be Prevented by Inhibition of Endothelin Receptors. Physiol Res 2018; 67:S227-S236. [DOI: 10.33549/physiolres.933842] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Over activation of the endothelin-1 (ET-1) system in disease states contributes to endothelial dysfunction. On the other hand, ET-1 promotes proliferation and survival of endothelial cells. Regulation of programmed cell death (PCD) pathways is critical for cell survival. Recently discovered necroptosis (regulated necrosis) is a pathological PCD mechanism mediated by the activation of toll like receptor 4 (TLR4), which also happens to stimulate ET-1 production in dendritic cells. To establish the effect of ET-1 on PCD and survival of human brain microvascular endothelial cells (BMVECs) under control and inflammatory conditions, BMVECs were treated with ET-1 (10 nM, 100 nM and 1 µM) or lipopolysaccharide (LPS, 100 ng/ml). ET receptors were blocked with bosentan (10 µM). Under normal growth conditions, exogenous ET-1 reduced BMVEC viability and migration at a relatively high concentration (1 µM). This was accompanied with activation of necroptosis and apoptosis marker genes. LPS decreased endogenous ET-1 secretion, increased ETB receptor expression and activated necroptosis. Even though ET-1 levels were low (less than 10 nM levels used under normal growth conditions), blocking of ET receptors with bosentan inhibited the necroptosis pathway and improved the cell migration ability of BMVECs, suggesting that under inflammatory conditions, ET-1 activates PCD pathways in BMVECs even at physiological levels.
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Affiliation(s)
| | | | | | - A. ERGUL
- Department of Physiology, Augusta University, Augusta, GA, USA
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12
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Dual function of peroxiredoxin I in lipopolysaccharide-induced osteoblast apoptosis via reactive oxygen species and the apoptosis signal-regulating kinase 1 signaling pathway. Cell Death Discov 2018; 4:47. [PMID: 29707240 PMCID: PMC5919897 DOI: 10.1038/s41420-018-0050-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 01/02/2023] Open
Abstract
Lipopolysaccharide (LPS)-induced osteoblast apoptosis is a prominent factor to the defect in periodontal tissue repair in periodontal disease. LPS challenge contributes to the production of reactive oxygen species (ROS) in periodontitis, and peroxiredoxin 1 (Prx1) is an antioxidant protein that protect cells against oxidative damage from ROS. Without LPS stimulation, apoptotic rates were higher in both Prx1 knockout (Prx1KO) and Prx1 overexpression (Prx1OE) cells compared with wild type. After LPS stimulation, intracellular ROS in Prx1KO cells showed the highest level and Prx1OE cells showed the least. Treatment with LPS significantly elevated the expression of Bax, Cyto-c, and caspase 3 in Prx1KO cells compared with wild type, although this could be completely abolished by NAC. In Prx1OE cells, the expression and activation of ASK1 were significantly increased, and this was slightly reduced by LPS stimulation. NQDI-1 completely abolished the increased phosphorylation of JNK and p38 and the expression of caspase 3 in LPS-stimulated cells. These results indicate that Prx1 eliminates intracellular ROS and exhibits a cytoprotective role in LPS-induced apoptosis. However, under physiological conditions, Prx1 overexpression acts as a H2O2 messenger, triggering the expression of ASK1 and its downstream cascades.
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13
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Aloin Suppresses Lipopolysaccharide-Induced Inflammatory Response and Apoptosis by Inhibiting the Activation of NF-κB. Molecules 2018; 23:molecules23030517. [PMID: 29495390 PMCID: PMC6017010 DOI: 10.3390/molecules23030517] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/09/2018] [Accepted: 02/17/2018] [Indexed: 12/30/2022] Open
Abstract
Numerous herbal-derived natural products are excellent anti-inflammatory agents. Several studies have reported that aloin, the major anthraquinone glycoside obtained from the Aloe species, exhibits anti-inflammatory activity. However, the molecular mechanism of this activity is not well understood. In this report, we found that aloin suppresses lipopolysaccharide-induced pro-inflammatory cytokine secretion and nitric oxide production, and downregulates the expression of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Aloin inhibits the phosphorylation and acetylation of the NF-κB p65 subunit by suppressing the upstream kinases p38 and Msk1, preventing LPS-induced p65 translocation to the nucleus. We have also shown that aloin inhibits LPS-induced caspase-3 activation and apoptotic cell death. Collectively, these findings suggest that aloin effectively suppresses the inflammatory response, primarily through the inhibition of NF-κB signaling.
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14
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Wright LH, Herr DJ, Brown SS, Kasiganesan H, Menick DR. Angiokine Wisp-1 is increased in myocardial infarction and regulates cardiac endothelial signaling. JCI Insight 2018; 3:95824. [PMID: 29467324 DOI: 10.1172/jci.insight.95824] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 01/10/2018] [Indexed: 12/17/2022] Open
Abstract
Myocardial infarctions (MIs) cause the loss of myocytes due to lack of sufficient oxygenation and latent revascularization. Although the administration of histone deacetylase (HDAC) inhibitors reduces the size of infarctions and improves cardiac physiology in small-animal models of MI injury, the cellular targets of the HDACs, which the drugs inhibit, are largely unspecified. Here, we show that WNT-inducible secreted protein-1 (Wisp-1), a matricellular protein that promotes angiogenesis in cancers as well as cell survival in isolated cardiac myocytes and neurons, is a target of HDACs. Further, Wisp-1 transcription is regulated by HDACs and can be modified by the HDAC inhibitor, suberanilohydroxamic acid (SAHA/vorinostat), after MI injury. We observe that, at 7 days after MI, Wisp-1 is elevated 3-fold greater in the border zone of infarction in mice that experience an MI injury and are injected daily with SAHA, relative to MI alone. Additionally, human coronary artery endothelial cells (HCAECs) produce WISP-1 and are responsive to autocrine WISP-1-mediated signaling, which functionally promotes their proangiogenic behavior. Altering endogenous expression of WISP-1 in HCAECs directly impacts their network density in vitro. Therapeutic interventions after a heart attack define the extent of infarct injury, cell survival, and overall prognosis. Our studies shown here identify a potentially novel cardiac angiokine, Wisp-1, that may contribute to beneficial post-MI treatment modalities.
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Affiliation(s)
| | | | - Symone S Brown
- College of Graduate Studies, Summer Undergraduate Research Program, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | - Donald R Menick
- Division of Cardiology, and.,Ralph H. Johnson VA Medical Center, Charleston, South Carolina, USA
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15
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Jang J, Yoon Y, Oh DJ. A calpain inhibitor protects against fractalkine production in lipopolysaccharide-treated endothelial cells. Kidney Res Clin Pract 2017; 36:224-231. [PMID: 28904873 PMCID: PMC5592889 DOI: 10.23876/j.krcp.2017.36.3.224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 04/20/2017] [Accepted: 05/10/2017] [Indexed: 11/06/2022] Open
Abstract
Background Fractalkine (CX3CL1) is a chemokine with a unique CX3C motif and is produced by endothelial cells stimulated with lipopolysaccharide (LPS), tumor necrosis factor (TNF)-α, interleukin (IL)-1, and interferon-γ. There have been several reports that the caspase/calpain system is activated in endotoxemia, which leads to cellular apoptosis and acute inflammatory processes. We aimed to determine the role of the caspase/calpain system in cell viability and regulation of fractalkine production in LPS-treated endothelial cells. Methods Human umbilical vein endothelial cells (HUVECs) were stimulated with 0.01–100 μg/mL of LPS to determine cell viability. The changes of CX3CL1 expression were compared in control, LPS (1 μg/mL)-, IL-1α (1 μg/mL)-, and IL-1β (1 μg/mL)-treated HUVECs. Cell viability and CX3CL1 production were compared with 50 μM of inhibitors of caspase-1, caspase-3, caspase-9, and calpain in LPS-treated HUVECs. Results Cell viability was significantly decreased from 1 to 100 μg/mL of LPS. Cell viability was significantly restored with inhibitors of caspase-1, caspase-3, caspase-9, and calpain in LPS-treated HUVECs. The expression of CX3CL1 was highest in IL-1β-treated HUVECs. CX3CL1 production was highly inhibited with a calpain inhibitor and significantly decreased with the individual inhibitors of caspase-1, caspase-3, and caspase-9. Conclusion The caspase/calpain system is an important modulator of cell viability and CX3CL1 production in LPS-treated endothelial cells.
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Affiliation(s)
- Jaewoong Jang
- Department of Microbiology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Yoosik Yoon
- Department of Microbiology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Dong-Jin Oh
- Department of Internal Medicine, Myongji Hospital, Seonam University College of Medicine, Goyang, Korea
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16
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κ-Carrageenan Enhances Lipopolysaccharide-Induced Interleukin-8 Secretion by Stimulating the Bcl10-NF- κB Pathway in HT-29 Cells and Aggravates C. freundii-Induced Inflammation in Mice. Mediators Inflamm 2017; 2017:8634865. [PMID: 28163398 PMCID: PMC5253498 DOI: 10.1155/2017/8634865] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 08/07/2016] [Accepted: 11/13/2016] [Indexed: 12/22/2022] Open
Abstract
Background. The dietary usage of carrageenan as common food additive has increased observably over the last 50 years. But there is substantial controversy about its safety. Methods. We investigated whether the κ-carrageenan could enhance lipopolysaccharide-induced IL-8 expression by studying its actions on the TLR4-NF-κB pathway. The aggravating effect of κ-carrageenan on Citrobacter freundii DBS100-induced intestinal inflammation was also investigated in a mouse model. Results. Our data show that κ-carrageenan pretreatment promoted LPS-induced IL-8 expression in HT-29 cells. Although CD14, MD-2, and TLR4 were upregulated, the binding of LPS was not enhanced. However, the pathway of Bcl10-NF-κB was triggered. Interestingly, κ-carrageenan competitively blocked the binding of FITC-LPS. Furthermore, pretreatment with κ-carrageenan for one week previous to gavage with C. freundii DBS100 markedly aggravated weight loss, mortality, and colonic damage. The secretion of cytokines was unbalanced and the ratio of Tregs was decreased significantly. In addition, κ-carrageenan, together with C. freundii DBS100, enhanced the transcription and secretion of TLR4 and NF-κB. Conclusions. κ-Carrageenan can synergistically activate LPS-induced inflammatory through the Bcl10-NF-κB pathway, as indicated by its aggravation of C. freundii DBS100-induced colitis in mice. General Significance. Our results suggest that κ-carrageenan serves as a potential inflammatory agent that magnifies existing intestinal inflammation.
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17
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Yi L, Huang X, Guo F, Zhou Z, Chang M, Tang J, Huan J. Lipopolysaccharide Induces Human Pulmonary Micro-Vascular Endothelial Apoptosis via the YAP Signaling Pathway. Front Cell Infect Microbiol 2016; 6:133. [PMID: 27807512 PMCID: PMC5069405 DOI: 10.3389/fcimb.2016.00133] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/30/2016] [Indexed: 01/21/2023] Open
Abstract
Gram-negative bacterial lipopolysaccharide (LPS) induces a pathologic increase in lung vascular leakage under septic conditions. LPS-induced human pulmonary micro-vascular endothelial cell (HPMEC) apoptosis launches and aggravates micro-vascular hyper-permeability and acute lung injury (ALI). Previous studies show that the activation of intrinsic apoptotic pathway is vital for LPS-induced EC apoptosis. Yes-associated protein (YAP) has been reported to positively regulate intrinsic apoptotic pathway in tumor cells apoptosis. However, the potential role of YAP protein in LPS-induced HPMEC apoptosis has not been determined. In this study, we found that LPS-induced activation and nuclear accumulation of YAP accelerated HPMECs apoptosis. LPS-induced YAP translocation from cytoplasm to nucleus by the increased phosphorylation on Y357 resulted in the interaction between YAP and transcription factor P73. Furthermore, inhibition of YAP by small interfering RNA (siRNA) not only suppressed the LPS-induced HPMEC apoptosis but also regulated P73-mediated up-regulation of BAX and down-regulation of BCL-2. Taken together, our results demonstrated that activation of the YAP/P73/(BAX and BCL-2)/caspase-3 signaling pathway played a critical role in LPS-induced HPMEC apoptosis. Inhibition of the YAP might be a potential therapeutic strategy for lung injury under sepsis.
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Affiliation(s)
- Lei Yi
- Department of Orthopedics, Shanghai Fengxian Central Hospital, Branch of The Sixth People's Hospital Affiliated to Shanghai Jiao Tong University Shanghai, China
| | - Xiaoqin Huang
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Feng Guo
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Zengding Zhou
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Mengling Chang
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Jiajun Tang
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
| | - Jingning Huan
- Department of Burn and Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University Shanghai, China
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18
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A Potential Mechanism for the Anti-Apoptotic Property of Koumine Involving Mitochondrial Pathway in LPS-Mediated RAW 264.7 Macrophages. Molecules 2016; 21:molecules21101317. [PMID: 27706063 PMCID: PMC6273091 DOI: 10.3390/molecules21101317] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 09/19/2016] [Accepted: 09/21/2016] [Indexed: 11/17/2022] Open
Abstract
Koumine is a kind of alkaloid extracted from Gelsemium elegans (G. elegans). Benth, which has shown promise as an anti-tumor, anxiolytic, and analgesic agent. In our present study, the effect of koumine on lipopolysaccharide (LPS)-mediated RAW 264.7 cell apoptosis was evaluated. MTT assays showed that koumine obviously increased cell viability in LPS-mediated RAW 264.7 macrophages. Preincubation with koumine ameliorated LPS-medicated apoptosis by decreasing reactive oxygen species (ROS) production, which resulted in a significant decrease in the levels of nitric oxide (NO) and inducible nitric oxide synthase (iNOS). In addition, koumine-pretreated RAW 264.7 macrophages exhibited reduction of LPS-induced levels of TNF-α, IL-1β, and IL-6 mRNA. Furthermore, pretreatment with koumine suppressed LPS-mediated p53 activation, loss of mitochondrial membrane potential, caspase-3 activation, decrease of Bcl-2 expression, and elevation of Bax and caspase-3 expressions, suggesting that koumine might act directly on RAW 264.7 cells to inhibit LPS-induced apoptosis. It seems as though the mechanism that koumine possesses is the anti-apoptotic effect mediated by suppressing production of ROS, activation of p53, and mitochondrial apoptotic pathways in RAW 264 cells. Koumine could potentially serve as a protective effect against LPS-induced apoptosis.
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19
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Slomiany B, Piotrowski J, Slomiany A. Effect of ebrotidine on Helicobacter pylori lipopolysaccharide-induced up-regulation of endothelin-1 in gastric mucosa. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519990050050401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Helicobacter pylori is recognized as a primary etiologic factor in the development of gastric disease. We applied the animal model of H. pylori lipopolysaccharide-induced acute gastritis to study the effect of the anti-ulcer agent, ebrotidine, on the course of mucosal inflammatory responses by analyzing over a period of 10 days the extent of epithelial cell apoptosis and the mucosal expression of endothelin-1 (ET-1), tumor necrosis factor α (TNFα), and the activity of constitutive (cNOS) and inducible (NOS-2) nitric oxide synthase. Rats, pretreated twice daily for 3 days with ebrotidine at 100 mg/kg or the vehicle, were subjected to intragastric application of H. pylori lipopolysaccharide at 50 µg/animal, and after 2, 4, and 10 additional days on the drug or vehicle regimen their mucosal tissue was used for histological and biochemical assessment. In the absence of ebrotidine, H. pylori lipopolysaccharide elicited within 2 days extensive mucosal inflammation accompanied by a significant increase in epithelial cell apoptosis (13.5-fold) and the mucosal expression of TNFα (11.7-fold), NOS-2 (9.3-fold), and ET-1 (2.9-fold), while cNOS activity showed a 5.5-fold decrease. The extent of mucosal inflammatory involvement reached a maximum by the 4th day and showed a decline by the 10th day. This was reflected in a marked reduction in epithelial cell apoptosis, a decrease in the mucosal expression of ET-1, TNFα and NOS-2, and the recovery in cNOS activity. Treatment with ebrotidine caused a reduction in the extent of mucosal inflammatory involvement elicited by the lipopolysaccharide and this effect of ebrotidine was reflected at the end of a 10 day period in a 61.3% reduction in inflammation, and a decrease in apoptosis (83%), TNFα (51.8%), ET-1 (27.6%) and NOS-2 (62.9%), while the expression of cNOS increased by 78.6%. The findings indicate that an increase in the ET-1 level elicited by H. pylori lipopolysaccharide, combined with a decline in cNOS, trigger the induction of TNFα which propagates the inflammatory process. We also show that ebrotidine is capable of suppressing the H. pylori-induced gastric mucosal inflammatory responses.
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Affiliation(s)
- B.L. Slomiany
- Research Center, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA,
| | - J. Piotrowski
- Research Center, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA
| | - A. Slomiany
- Research Center, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA
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20
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Singh KK, Matkar PN, Muhammad S, Quan A, Gupta V, Teoh H, Al-Omran M, Verma S. Investigation of novel LPS-induced differentially expressed long non-coding RNAs in endothelial cells. Mol Cell Biochem 2016; 421:157-68. [PMID: 27565812 DOI: 10.1007/s11010-016-2797-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/10/2016] [Indexed: 12/11/2022]
Abstract
The molecular mechanisms responsible for sepsis-induced endothelial dysfunction leading to an elevated risk of cardiovascular diseases remain undefined. Endotoxic or septic shock is a potentially lethal complication of systemic infection by Gram-negative bacteria. Lipopolysaccharide (LPS) is a critical glycolipid component of the outer wall of Gram-negative bacteria, and many of the sepsis-associated cellular signals by Gram-negative bacteria are attributed to LPS. Given that LPS has an established role in the pathophysiology of sepsis and long non-coding RNAs (lncRNAs) have been reported to critically regulate vascular homeostasis, a systematic transcriptional survey was conducted to evaluate the impact of LPS stimulation on human endothelial lncRNAs and protein-coding transcripts (mRNAs). LncRNAs and mRNAs from LPS-treated (100 ng/mL; 24 h) human umbilical vein endothelial cells (HUVECs) were profiled with the Arraystar Human lncRNA Expression Microarray V3.0. Of the 30,584 lncRNAs screened, 871 were significantly upregulated and 1068 significantly downregulated (p < 0.05) in response to LPS. In the same HUVEC samples, 733 of the 26,106 mRNAs screened were upregulated and 536 were downregulated. Among the differentially expressed lncRNAs, AL132709.5 was the most upregulated (~70 fold) and CTC-459I6.1 the most downregulated (~28 fold). Bioinformatics analyses indicated that the differentially expressed upregulated mRNAs are primarily enriched in cytokine-cytokine receptor interaction, infectious diseases, TNF signaling pathway, FoxO signaling pathway, and pathways in cancer. This is the first lncRNA and mRNA transcriptome profile of LPS-mediated changes in human endothelial cells. These observations may reveal novel endothelial targets of LPS that may be involved in the vascular pathology of sepsis.
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Affiliation(s)
- Krishna K Singh
- Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada. .,Division of Vascular Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada. .,Department of Surgery, University of Toronto, Toronto, ON, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
| | - Pratiek N Matkar
- Division of Cardiology, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Shoaib Muhammad
- Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada
| | - Adrian Quan
- Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada
| | - Vijay Gupta
- Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada
| | - Hwee Teoh
- Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada.,Division of Endocrinology and Metabolism, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada
| | - Mohammed Al-Omran
- Division of Vascular Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,King Saud University-Li Ka Shing Collaborative Research Program, Department of Surgery, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Subodh Verma
- Division of Cardiac Surgery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 8th Floor, Bond Wing, 30 Bond Street, Toronto, ON, M5B 1W8, Canada. .,Department of Surgery, University of Toronto, Toronto, ON, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
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21
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Rotation of Vibrio fischeri Flagella Produces Outer Membrane Vesicles That Induce Host Development. J Bacteriol 2016; 198:2156-65. [PMID: 27246572 DOI: 10.1128/jb.00101-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/20/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Using the squid-vibrio association, we aimed to characterize the mechanism through which Vibrio fischeri cells signal morphogenesis of the symbiotic light-emitting organ. The symbiont releases two cell envelope molecules, peptidoglycan (PG) and lipopolysaccharide (LPS) that, within 12 h of light organ colonization, act in synergy to trigger normal tissue development. Recent work has shown that outer membrane vesicles (OMVs) produced by V. fischeri are sufficient to induce PG-dependent morphogenesis; however, the mechanism(s) of OMV release by these bacteria has not been described. Like several genera of both beneficial and pathogenic bacteria, V. fischeri cells elaborate polar flagella that are enclosed by an extension of the outer membrane, whose function remains unclear. Here, we present evidence that along with the well-recognized phenomenon of blebbing from the cell's surface, rotation of this sheathed flagellum also results in the release of OMVs. In addition, we demonstrate that most of the development-inducing LPS is associated with these OMVs and that the presence of the outer membrane protein OmpU but not the LPS O antigen on these OMVs is important in triggering normal host development. These results also present insights into a possible new mechanism of LPS release by pathogens with sheathed flagella. IMPORTANCE Determining the function(s) of sheathed flagella in bacteria has been challenging, because no known mutation results only in the loss of this outer membrane-derived casing. Nevertheless, the presence of a sheathed flagellum in such host-associated genera as Vibrio, Helicobacter, and Brucella has led to several proposed functions, including physical protection of the flagella and masking of their immunogenic flagellins. Using the squid-vibrio light organ symbiosis, we demonstrate another role, that of V. fischeri cells require rotating flagella to induce apoptotic cell death within surface epithelium, which is a normal step in the organ's development. Further, we present evidence that this rotation releases apoptosis-triggering lipopolysaccharide in the form of outer membrane vesicles. Such release may also occur by pathogens but with different outcomes for the host.
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22
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Begović L, Antunovic M, Matic I, Furcic I, Baricevic A, Vojvoda Parcina V, Peharec Štefanić P, Nagy B, Marijanovic I. Effect of UVC radiation on mouse fibroblasts deficient for FAS-associated protein with death domain. Int J Radiat Biol 2016; 92:475-82. [PMID: 27258329 DOI: 10.1080/09553002.2016.1186298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE Ultraviolet (UV) radiation-induced apoptosis enabled us to study the mechanism of DNA damage and to investigate how cells avoid consequences of damaged DNA. Cells with extensive DNA damage activate extrinsic and intrinsic pathways of apoptosis. The extrinsic pathway is coupled to a FAS-associated protein with death domain (FADD), an adaptor protein molecule necessary for mediating apoptotic signals through the cell. MATERIALS AND METHODS Viability and apoptosis of wild-type and FADD-deficient mouse embryonic fibroblasts were investigated 1, 3, 24 and 48 h after exposure to three doses (50, 75 and 300 J/m(2)) of UVC radiation. Morphological changes were observed using DNA binding dyes (Hoechst and propidium iodide) while biochemical changes were monitored using immunodetection of the poly (ADP-ribose) polymerase (PARP) protein cleavage and caspase-3 activity assay. RESULTS Results showed that the difference in cell death response between wild-type and FADD-deficient cells depended on dose and incubation time after exposure to UVC radiation. FADD-deficient cells are more sensitive to UVC radiation. Even though FADD-deficient cells lack an adapter protein of apoptotic extrinsic pathway, higher doses of UVC triggered their apoptotic response, while wild-type cells die mainly due to necrosis. A different pattern of caspase 3 activity and PARP cleavage was observed 24 h after radiation between two cell lines confirming higher apoptotic response in FADD-deficient cells. CONCLUSIONS Wild-type cells can execute apoptosis via both, the mitochondrial and the receptor-mediated pathway whereas FADD-deficient cells can only activate the intrinsic pathway. There is a difference in UVC radiation response between two cell lines indicating the role of FADD in the selection of cell death modality.
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Affiliation(s)
- Lidija Begović
- a Department of Biology , University of J. J. Strossmayer in Osijek , Osijek , Croatia
| | - Maja Antunovic
- b Division of Molecular Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia
| | - Igor Matic
- b Division of Molecular Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia
| | - Ivana Furcic
- c Institute for Anthropological Research , Zagreb , Croatia
| | - Ana Baricevic
- d Rudjer Boskovic Institute, Center for Marine Research , Rovinj , Croatia
| | - Valerija Vojvoda Parcina
- e Center for Research and Knowledge Transfer in Biotechnology, University of Zagreb , Zagreb , Croatia
| | - Petra Peharec Štefanić
- b Division of Molecular Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia
| | - Biserka Nagy
- b Division of Molecular Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia
| | - Inga Marijanovic
- b Division of Molecular Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia
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23
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Wang Y, Song E, Bai B, Vanhoutte PM. Toll-like receptors mediating vascular malfunction: Lessons from receptor subtypes. Pharmacol Ther 2015; 158:91-100. [PMID: 26702901 DOI: 10.1016/j.pharmthera.2015.12.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Toll-like receptors (TLR) are a subfamily of pattern recognition receptors (PRR) implicated in a variety of vascular abnormalities. However, the pathophysiological role and the interplay between different TLR-mediated innate and adaptive immune responses during the development of vascular diseases remain largely unspecified. TLR are widely distributed in both immune and nonimmune cells in the blood vessel wall. The expressions and locations of TLR are dynamically regulated in response to distinct molecular patterns derived from pathogens or damaged host cells. As a result, the outcome of TLR signaling is agonist- and cell type-dependent. A better understanding of discrete TLR signaling pathways in the vasculature will provide unprecedented opportunities for the discovery of novel therapies in many inflammatory vascular diseases. The present brief review discusses the role of individual TLR in controlling cellular functions of the vascular system, by focusing on the inflammatory responses within the blood vessel wall which contribute to the development of hypertension and atherosclerosis.
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Affiliation(s)
- Yu Wang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
| | - Erfei Song
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Bo Bai
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Paul M Vanhoutte
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
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24
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Walshe CM, Laffey JG, Kevin L, O’Toole D. Sepsis protects the myocardium and other organs from subsequent ischaemic/reperfusion injury via a MAPK-dependent mechanism. Intensive Care Med Exp 2015; 3:35. [PMID: 26215802 PMCID: PMC4513033 DOI: 10.1186/s40635-014-0035-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 12/09/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Sepsis has been shown to precondition the intact heart against ischaemia/reperfusion (IR) injury, and prior endotoxin exposure of cells in in vitro models has shown evidence of protection against subsequent simulated ischaemia. Our aim in this study is to validate these findings and further investigate the signaling pathways involved. METHODS Adult male Sprague Dawley rats were randomised to control (n = 7) or caecal ligation and perforation (CLP)-induced sepsis (n = 7). Hearts were harvested at 48 h, suspended in Langendorff mode and subjected to 30-min global ischaemia followed by 90-min reperfusion. In subsequent experiments, designed to determine the mechanisms by which sepsis protected against ischaemic injury, endotoxin-stimulated isolated cardiomyocytes, pulmonary A549 cells and renal HK2 cells were subjected to normoxic and hypoxic conditions. The roles of key pathways, including mitogen-activated protein (MAP) kinases extracellular-regulated protein kinase (ERK) 1/2, p38 MAPK (p38), c-Jun NH2-terminal protein kinase (JNK)), and nuclear factor-kappaB (NF-κB) were examined. RESULTS Systemic sepsis protected isolated hearts from subsequent ischaemic/reperfusion-induced injury, enhancing functional recovery on reperfusion [developed left ventricular pressure ((d)LVP) mean(SE) 66.63(±10.7) mmHg vs. 54.13(±9.9) mmHg; LVPmax at 60 min 67.29(±11.9) vs. 72.48(±9.3), sepsis vs. control] despite significantly reduced baseline LV function in CLP animals (p < 0.001). Septic preconditioning significantly reduced infarct size after IR injury (p < 0.05). Endotoxin exposure protected isolated cardiomyocytes against hypoxia-induced cell death (p < 0.001). This effect appeared mediated in part via the p38, JNK and NF-κB pathways, but was independent of the ERK pathway, and did not appear to be mediated via HMGB1. The preconditioning effect of endotoxin was also demonstrated in isolated kidney and lung cells, suggesting that this preconditioning effect of sepsis is not confined to the myocardium. CONCLUSIONS Sepsis preconditions the isolated rat heart against myocardial IR injury. These effects appeared to be mediated in part via the p38, JNK and NF-κB and pathways, but were independent of the ERK and HMGB pathways.
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Affiliation(s)
- Criona M Walshe
- Department of Anaesthesia, Galway University Hospitals and National University of Ireland, University Road, Galway, Ireland
| | - John G Laffey
- Department of Anaesthesia, Galway University Hospitals and National University of Ireland, University Road, Galway, Ireland
| | - Leo Kevin
- Department of Anaesthesia, Galway University Hospitals and National University of Ireland, University Road, Galway, Ireland
| | - Daniel O’Toole
- Department of Anaesthesia, Galway University Hospitals and National University of Ireland, University Road, Galway, Ireland
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Jiang WL, Zhang YF, Xia QQ, Zhu J, Yu X, Fan T, Wang F. MicroRNA-19a regulates lipopolysaccharide-induced endothelial cell apoptosis through modulation of apoptosis signal-regulating kinase 1 expression. BMC Mol Biol 2015; 16:11. [PMID: 25982447 PMCID: PMC4446110 DOI: 10.1186/s12867-015-0034-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/19/2015] [Indexed: 01/07/2023] Open
Abstract
Background MicroRNAs, small non-encoding RNAs that post-transcriptionally modulate expression of their target genes, have been implicated as critical regulatory molecules in endothelial cells. Results In the present study, we found that overexpression of miR-19a protects endothelial cells from lipopolysaccharide (LPS)-induced apoptosis through the apoptosis signal-regulating kinase 1 (ASK1)/p38 pathway. Quantitative real-time PCR demonstrated that the expression of miR-19a in endothelial cell was markedly down-regulated by LPS stimulation. Furthermore, LPS-induced apoptosis was significantly inhibited by over-expression of miR-19a. Finally, both a luciferase reporter assay and western blot analysis showed that ASK1 is a direct target of miR-19a. Conclusions MiR-19a regulates ASK1 expression by targeting specific binding sites in the 3’ untranslated region of ASK1 mRNA. Overexpression of miR-19a is an effective method to protect against LPS-induced apoptosis of endothelial cells. Electronic supplementary material The online version of this article (doi:10.1186/s12867-015-0034-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wei-Long Jiang
- Department of Respiration, Jiangyin Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Jiangyin City, Jiangsu Province, 214400, China.
| | - Yu-Feng Zhang
- Department of Respiration, Jiangyin Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Jiangyin City, Jiangsu Province, 214400, China.
| | - Qing-Qing Xia
- Department of Respiration, Jiangyin Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Jiangyin City, Jiangsu Province, 214400, China.
| | - Jian Zhu
- Department of Neurology, Jiangyin Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Jiangyin City, Jiangsu Province, 214400, China.
| | - Xin Yu
- Department of Internal Medicine, Jiangyin Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Jiangyin City, Jiangsu Province, 214400, China.
| | - Tao Fan
- Department of Neurology, Jiangyin Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Jiangyin City, Jiangsu Province, 214400, China.
| | - Feng Wang
- Department of Neurology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200080, China.
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Hou YS, Liu LY, Chai JK, Yu YH, Duan HJ, Hu Q, Yin HN, Wang YH, Zhuang SB, Fan J, Chu WL, Ma L. Lipopolysaccharide pretreatment inhibits LPS-induced human umbilical cord mesenchymal stem cell apoptosis via upregulating the expression of cellular FLICE-inhibitory protein. Mol Med Rep 2015; 12:2521-8. [PMID: 25955291 PMCID: PMC4464426 DOI: 10.3892/mmr.2015.3723] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 04/10/2015] [Indexed: 02/06/2023] Open
Abstract
Mesenchymal stem cell (MSC)-based regenerative therapy is currently regarded as a novel approach with which to repair damaged tissues. However, the efficiency of MSC transplantation is limited due to the low survival rate of engrafted MSCs. Lipopolysaccharide (LPS) production is increased in numerous diseases and serves an essential function in the regulation of apoptosis in a variety of cell types. Previous studies have indicated that low-dose LPS pretreatment contributes to cytoprotection. In the current study, LPS was demonstrated to induce apoptosis in human umbilical cord mesenchymal stem cells (hUCMSCs) via the activation of caspase, in a dose-dependent manner. Low-dose LPS pretreatment may protect hUCMSCs against apoptosis induced by high-dose LPS, by upregulating the expression of cellular FADD-like IL-1β-converting enzyme-inhibitory protein (c-FLIP). The results of the present study indicate that pretreatment with an appropriate concentration of LPS may alleviate high-dose LPS-induced apoptosis.
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Affiliation(s)
- Yu Sen Hou
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Ling Ying Liu
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Jia Ke Chai
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Yong Hui Yu
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Hong Jie Duan
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Quan Hu
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Hui Nan Yin
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Yi He Wang
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Shu Bo Zhuang
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Jun Fan
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Wan Li Chu
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
| | - Li Ma
- Department of Burns and Plastic Surgery, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, P.R. China
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Webb KC, Eby JM, Hariharan V, Hernandez C, Luiten RM, Le Poole IC. Enhanced bleaching treatment: opportunities for immune-assisted melanocyte suicide in vitiligo. Exp Dermatol 2014; 23:529-33. [PMID: 24840876 DOI: 10.1111/exd.12449] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2014] [Indexed: 01/13/2023]
Abstract
Depigmentation in vitiligo occurs by progressive loss of melanocytes from the basal layer of the skin, and can be psychologically devastating to patients. T cell-mediated autoimmunity explains the progressive nature of this disease. Rather than being confronted with periods of rapid depigmentation and bouts of repigmentation, patients with long-standing, treatment-resistant vitiligo can undergo depigmentation treatment. The objective is to remove residual pigmentation to achieve a cosmetically acceptable result--that of skin with a uniform appearance. In the United States, only the use of mono-benzyl ether of hydroquinone (MBEH) is approved for this purpose. However, satisfactory results can take time to appear, and there is a risk of repigmentation. MBEH induces necrotic melanocyte death followed by a cytotoxic T-cell response to remaining, distant melanocytes. As cytotoxic T-cell responses are instrumental to depigmentation, we propose that combining MBEH with immune adjuvant therapies will accelerate immune-mediated melanocyte destruction to achieve faster, more definitive depigmentation than with MBEH alone. As Toll-like Receptor (TLR) agonists--imiquimod, CpG, and Heat Shock Protein 70 (HSP 70)--all support powerful Th1 responses, we propose that using MBEH in combination with these agents can achieve superior depigmentation results for vitiligo patients.
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Affiliation(s)
- Kirsten C Webb
- Department of Dermatology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
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Brennan CA, Hunt JR, Kremer N, Krasity BC, Apicella MA, McFall-Ngai MJ, Ruby EG. A model symbiosis reveals a role for sheathed-flagellum rotation in the release of immunogenic lipopolysaccharide. eLife 2014; 3:e01579. [PMID: 24596150 PMCID: PMC3941163 DOI: 10.7554/elife.01579] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Bacterial flagella mediate host–microbe interactions through tissue tropism during colonization, as well as by activating immune responses. The flagellar shaft of some bacteria, including several human pathogens, is encased in a membranous sheath of unknown function. While it has been hypothesized that the sheath may allow these bacteria to evade host responses to the immunogenic flagellin subunit, this unusual structural feature has remained an enigma. Here we demonstrate that the rotation of the sheathed flagellum in both the mutualist Vibrio fischeri and the pathogen Vibrio cholerae promotes release of a potent bacteria-derived immunogen, lipopolysaccharide, found in the flagellar sheath. We further present a new role for the flagellar sheath in triggering, rather than circumventing, host immune responses in the model squid-vibrio symbiosis. Such an observation not only has implications for the study of bacterial pathogens with sheathed flagella, but also raises important biophysical questions of sheathed-flagellum function. DOI:http://dx.doi.org/10.7554/eLife.01579.001 While a few of the bacteria that live in and on the bodies of humans and other animals are harmful and can cause disease, most others can offer benefits to their hosts. Many bacteria—including some important human pathogens—have tails called flagella that rotate to move the bacteria inside its host. However, the immune system can detect parts of these flagella and eliminate the pathogen. Bacterial flagella are made from filaments of proteins, and some flagella are also enclosed by a sheath that is similar to the outer membrane that encloses certain bacteria. The function of this sheath is unclear, although some researchers have suggested that it might prevent the immune system from detecting the proteins in the flagellum. Now, by studying the interactions between the Hawaiian bobtail squid and a marine bacterium, Brennan et al. show that the sheath can actually alert the host that the bacteria are around. The Hawaiian bobtail squid collects bioluminescent bacteria within a so-called ‘light organ’. This organ undergoes a number of developmental changes to house the bacteria, and the squid then uses the light from the bacteria to mask its own shadow, which helps it to avoid being detected by predators. Brennan et al. compared how wild-type bacteria and mutant bacteria that either had no flagella, or had flagella that did not rotate, interacted with young squid. Only bacteria with working flagella were able to trigger the normal development of the squid’s light organ, which suggests that the rotating flagella are releasing the signal that tells the squid that the beneficial bacteria are present. Brennan et al. demonstrated that the rotation of sheathed flagella led to the release of a molecule called lipopolysaccharide. This molecule is known to activate the immune system in animals, and it is one of the bacterial signals that the squid responds to. Moreover, when the flagella of other bacteria with sheaths—such as those that cause cholera—are rotating, there is also an increase in the release of lipopolysaccharide. However, rotation of the flagella of bacteria without sheaths has no such effect. The next challenge will be to test the importance of this release of lipopolysaccharide from rotating flagella on the outcome of bacterial diseases of humans and other animals. DOI:http://dx.doi.org/10.7554/eLife.01579.002
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Affiliation(s)
- Caitlin A Brennan
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, United States
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Gill SE, Taneja R, Rohan M, Wang L, Mehta S. Pulmonary microvascular albumin leak is associated with endothelial cell death in murine sepsis-induced lung injury in vivo. PLoS One 2014; 9:e88501. [PMID: 24516666 PMCID: PMC3917898 DOI: 10.1371/journal.pone.0088501] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 01/10/2014] [Indexed: 11/19/2022] Open
Abstract
Sepsis is a systemic inflammatory response that targets multiple components of the cardiovascular system including the microvasculature. Microvascular endothelial cells (MVEC) are central to normal microvascular function, including maintenance of the microvascular permeability barrier. Microvascular/MVEC dysfunction during sepsis is associated with barrier dysfunction, resulting in the leak of protein-rich edema fluid into organs, especially the lung. The specific role of MVEC apoptosis in septic microvascular/MVEC dysfunction in vivo remains to be determined. To examine pulmonary MVEC death in vivo under septic conditions, we used a murine cecal ligation/perforation (CLP) model of sepsis and identified non-viable pulmonary cells with propidium iodide (PI) by intravital videomicroscopy (IVVM), and confirmed this by histology. Septic pulmonary microvascular Evans blue (EB)-labeled albumin leak was associated with an increased number of PI-positive cells, which were confirmed to be predominantly MVEC based on specific labeling with three markers, anti-CD31 (PECAM), anti-CD34, and lectin binding. Furthermore, this septic death of pulmonary MVEC was markedly attenuated by cyclophosphamide-mediated depletion of neutrophils (PMN) or use of an anti-CD18 antibody developed for immunohistochemistry but shown to block CD18-dependent signaling. Additionally, septic pulmonary MVEC death was iNOS-dependent as mice lacking iNOS had markedly fewer PI-positive MVEC. Septic PI-positive pulmonary cell death was confirmed to be due to apoptosis by three independent markers: caspase activation by FLIVO, translocation of phosphatidylserine to the cell surface by Annexin V binding, and DNA fragmentation by TUNEL. Collectively, these findings indicate that septic pulmonary MVEC death, putatively apoptosis, is a result of leukocyte activation and iNOS-dependent signaling, and in turn, may contribute to pulmonary microvascular barrier dysfunction and albumin hyper-permeability during sepsis.
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Affiliation(s)
- Sean E. Gill
- Pulmonary Inflammation, Injury, and Repair Lab (PIIRL), Centre for Critical Illness Research, Lawson Health Research Institute, London Health Sciences Center, London, Ontario, Canada
- Division of Respirology, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Ravi Taneja
- Pulmonary Inflammation, Injury, and Repair Lab (PIIRL), Centre for Critical Illness Research, Lawson Health Research Institute, London Health Sciences Center, London, Ontario, Canada
- Department of Critical Care Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Department of Anesthesia and Perioperative Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Marta Rohan
- Pulmonary Inflammation, Injury, and Repair Lab (PIIRL), Centre for Critical Illness Research, Lawson Health Research Institute, London Health Sciences Center, London, Ontario, Canada
| | - Lefeng Wang
- Pulmonary Inflammation, Injury, and Repair Lab (PIIRL), Centre for Critical Illness Research, Lawson Health Research Institute, London Health Sciences Center, London, Ontario, Canada
| | - Sanjay Mehta
- Pulmonary Inflammation, Injury, and Repair Lab (PIIRL), Centre for Critical Illness Research, Lawson Health Research Institute, London Health Sciences Center, London, Ontario, Canada
- Division of Respirology, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- * E-mail:
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Thompson MR, Xu D, Williams BR. Activating Transcription Factor 3 Contributes to Toll-Like Receptor-Mediated Macrophage Survival via Repression ofBaxandBak. J Interferon Cytokine Res 2013; 33:682-93. [DOI: 10.1089/jir.2013.0007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Matthew R. Thompson
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Dakang Xu
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Bryan R.G. Williams
- Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
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Magnusdottir A, Vidarsson H, Björnsson JM, Örvar BL. Barley grains for the production of endotoxin-free growth factors. Trends Biotechnol 2013; 31:572-80. [DOI: 10.1016/j.tibtech.2013.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/11/2013] [Accepted: 06/12/2013] [Indexed: 02/07/2023]
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Duarte S, Arango D, Parihar A, Hamel P, Yasmeen R, Doseff AI. Apigenin protects endothelial cells from lipopolysaccharide (LPS)-induced inflammation by decreasing caspase-3 activation and modulating mitochondrial function. Int J Mol Sci 2013; 14:17664-79. [PMID: 23989609 PMCID: PMC3794747 DOI: 10.3390/ijms140917664] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/30/2013] [Accepted: 08/16/2013] [Indexed: 11/17/2022] Open
Abstract
Acute and chronic inflammation is characterized by increased reactive oxygen species (ROS) production, dysregulation of mitochondrial metabolism and abnormal immune function contributing to cardiovascular diseases and sepsis. Clinical and epidemiological studies suggest potential beneficial effects of dietary interventions in inflammatory diseases but understanding of how nutrients work remains insufficient. In the present study, we evaluated the effects of apigenin, an anti-inflammatory flavonoid abundantly found in our diet, in endothelial cells during inflammation. Here, we show that apigenin reduced lipopolysaccharide (LPS)-induced apoptosis by decreasing ROS production and the activity of caspase-3 in endothelial cells. Apigenin conferred protection against LPS-induced mitochondrial dysfunction and reestablished normal mitochondrial complex I activity, a major site of electron leakage and superoxide production, suggesting its ability to modulate endothelial cell metabolic function during inflammation. Collectively, these findings indicate that the dietary compound apigenin stabilizes mitochondrial function during inflammation preventing endothelial cell damage and thus provide new translational opportunities for the use of dietary components in the prevention and treatment of inflammatory diseases.
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Affiliation(s)
- Silvia Duarte
- Department of Molecular Genetics, the Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; E-Mails: (S.D.); (D.A.); (A.P.); (P.H.); (R.Y.)
- Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- The Heart and Lung Research Institute, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
| | - Daniel Arango
- Department of Molecular Genetics, the Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; E-Mails: (S.D.); (D.A.); (A.P.); (P.H.); (R.Y.)
- Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- The Heart and Lung Research Institute, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- Molecular, Cellular and Development Biology Graduate Program, the Ohio State University, 333 West 10th Avenue, Columbus, OH 43210, USA
| | - Arti Parihar
- Department of Molecular Genetics, the Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; E-Mails: (S.D.); (D.A.); (A.P.); (P.H.); (R.Y.)
- Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- The Heart and Lung Research Institute, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- Department of Biological Sciences, Government Postgraduate College of Excellence, Vikram University, Dashehra Maidan, Ujjain 456010, MP, India
| | - Patrice Hamel
- Department of Molecular Genetics, the Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; E-Mails: (S.D.); (D.A.); (A.P.); (P.H.); (R.Y.)
- Department of Molecular and Cellular Biochemistry, the Ohio State University, 1645 Neil Avenue, Columbus, OH 43210, USA
| | - Rumana Yasmeen
- Department of Molecular Genetics, the Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; E-Mails: (S.D.); (D.A.); (A.P.); (P.H.); (R.Y.)
- Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- The Heart and Lung Research Institute, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
| | - Andrea I. Doseff
- Department of Molecular Genetics, the Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA; E-Mails: (S.D.); (D.A.); (A.P.); (P.H.); (R.Y.)
- Department of Internal Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
- The Heart and Lung Research Institute, the Ohio State University, 473 West 12th Avenue, Columbus, OH 43210, USA
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Lund SA, Wilson CL, Raines EW, Tang J, Giachelli CM, Scatena M. Osteopontin mediates macrophage chemotaxis via α4 and α9 integrins and survival via the α4 integrin. J Cell Biochem 2013. [PMID: 23192608 DOI: 10.1002/jcb.24462] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Osteopontin (OPN) is highly expressed by macrophages and plays a key role in the pathology of several chronic inflammatory diseases including atherosclerosis and the foreign body reaction. However, the molecular mechanism behind OPN regulation of macrophage functions is not well understood. OPN is a secreted molecule and interacts with several integrins via two domains: the RGD sequence binding to α(v) -containing integrins, and the SLAYGLR sequence binding to α(4) β(1), α(4) β(7), and α(9) β(1) integrins. Here we determined the role of OPN in macrophage survival, chemotaxis, and activation state. For survival studies, OPN treated-bone marrow derived macrophages (BMDMs) were challenged with growth factor withdrawal and neutralizing integrin antibodies. We found that survival in BMDMs is mediated primarily through the α(4) integrin. In chemotaxis studies, we observed that migration to OPN was blocked by neutralizing α(4) and α(9) integrin antibodies. Further, OPN did not affect macrophage activation as measured by IL-12 production. Finally, the relative contributions of the RGD and the SLAYGLR functional domains of OPN to leukocyte recruitment were evaluated in an in vivo model. We generated chimeric mice expressing mutated forms of OPN in myeloid-derived leukocytes, and found that the SLAYGLR functional domain of OPN, but not the RGD, mediates macrophage accumulation in response to thioglycollate-elicited peritonitis. Collectively, these data indicate that α(4) and α(9) integrins interacting with OPN via the SLAYGLR domain play a key role in macrophage biology by regulating migration, survival, and accumulation.
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Affiliation(s)
- Susan Amanda Lund
- Department of Bioengineering, University of Washington, Seattle, WA 98109, USA
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Jiang X, Kanda T, Tanaka T, Wu S, Nakamoto S, Imazeki F, Yokosuka O. Lipopolysaccharide blocks induction of unfolded protein response in human hepatoma cell lines. Immunol Lett 2013; 152:8-15. [PMID: 23578665 DOI: 10.1016/j.imlet.2013.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/29/2013] [Accepted: 03/29/2013] [Indexed: 01/15/2023]
Abstract
In the present study, we examined whether unfolded protein response (UPR) determined the hepatic cell damage induced by an innate immune response including TLR signaling pathways. We observed that lipopolysaccharide (LPS) transcriptionally downregulates 78-kDa glucose-regulated protein/immunoglobulin heavy-chain binding protein (GRP78/Bip), known to confer resistance to apoptosis. We also observed that LPS blocked the induction of UPR and led to poly(ADP-ribose) polymerase (PARP) cleavage in hepatocytes. We also demonstrated that overexpression of GRP78 rescued HepG2 cells treated with LPS from PARP cleavage. These data suggest that UPR downregulation could be a collateral effect of the LPS treatment. We speculate that UPR is an important factor of hepatic cell damage induced by an innate immune response.
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Affiliation(s)
- Xia Jiang
- Department of Gastroenterology and Nephrology, Chiba University, Graduate School of Medicine, Chuo-ku, Chiba, Japan
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Amiloride attenuates lipopolysaccharide-accelerated atherosclerosis via inhibition of NHE1-dependent endothelial cell apoptosis. Acta Pharmacol Sin 2013; 34:231-8. [PMID: 23274414 DOI: 10.1038/aps.2012.155] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AIM To investigate the effects of the potassium-sparing diuretic amiloride on endothelial cell apoptosis during lipopolysaccharide (LPS)-accelerated atherosclerosis. METHODS Human umbilical vein endothelial cells (HUVECs) were exposed to LPS (100 ng/mL) in the presence of drugs tested. The activity of Na(+)/H(+) exchanger 1 (NHE1) and calpain, intracellular free Ca(2+)level ([Ca(2+)](i)), as well as the expression of apoptosis-related proteins in the cells were measured. For in vivo study, ApoE-deficient (ApoE(-/-)) mice were fed high-fat diets with 0.5% (w/w) amiloride for 4 weeks and LPS (10 μg/mouse) infusion into caudal veins. Afterwards, atherosclerotic lesions, NHE1 activity and Bcl-2 expression in the aortic tissues were evaluated. RESULTS LPS treatment increased NHE1 activity and [Ca(2+)](i) in HUVECs in a time-dependent manner, which was associated with increased activity of the Ca(2+)-dependent protease calpain. Amiloride (1-10 μmol/L) significantly suppressed LPS-induced increases in NHE1 activity, [Ca(2+)](i). and calpain activity. In the presence of the Ca(2+) chelator BAPTA (0.5 mmol/L), LPS-induced increase of calpain activity was also abolished. In LPS-treated HUVECs, the expression of Bcl-2 protein was significantly decreased without altering its mRNA level. In the presence of amiloride (10 μmol/L) or the calpain inhibitor ZLLal (50 μmol/L), the down-regulation of Bcl-2 protein by LPS was blocked. LPS treatment did not alter the expression of Bax and Bak proteins in HUVECs. In the presence of amiloride, BAPTA or ZLLal, LPS-induced HUVEC apoptosis was significantly attenuated. In ApoE(-/-) mice, administration of amiloride significantly suppressed LPS-accelerated atherosclerosis and LPS-induced increase of NHE1 activity, and reversed LPS-induced down-regulation of Bcl-2 expression. CONCLUSION LPS stimulates NHE1 activity, increases [Ca(2+)](i), and activates calpain, which leads to endothelial cell apoptosis related to decreased Bcl-2 expression. Amiloride inhibits NHE1 activity, thus attenuates LPS-accelerated atherosclerosis in mice.
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Bustamante J, Tamayo E, Herreros J. Genomics in cardiovascular diseases: analysis of the importance of the toll-like receptor signaling pathway. Int J Gen Med 2012. [PMID: 23204853 PMCID: PMC3508562 DOI: 10.2147/ijgm.s33416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The development of techniques for genomics study makes it possible for us to further our knowledge about the physiopathology of various immunological or infectious diseases. These techniques improve our understanding of the development and evolution of such diseases, including those of cardiovascular origin, whilst they help to bring about the design of new therapeutic strategies. We are reviewing the genetic alterations of immunity in said field, and focusing on the signaling pathway of toll-like receptors because not only does this play a decisive role in response to microorganisms, it is also heavily involved in modulating the inflammatory response to tissue damage, a side effect of numerous cardiovascular diseases. These alterations in tissue homeostasis are present under a wide range of circumstances, such as reperfusion ischemia (myocardial infarction) phenomena, arteriosclerosis, or valvulopathy.
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Affiliation(s)
- J Bustamante
- Department of Cardiovascular Surgery, Hospital Universitario La Princesa, Madrid
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Zhao Y, Cui G, Zhang N, Liu Z, Sun W, Peng Q. Lipopolysaccharide induces endothelial cell apoptosis via activation of Na(+)/H(+) exchanger 1 and calpain-dependent degradation of Bcl-2. Biochem Biophys Res Commun 2012; 427:125-32. [PMID: 22995319 DOI: 10.1016/j.bbrc.2012.09.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 09/06/2012] [Indexed: 11/16/2022]
Abstract
The calcium-dependent protease calpain is involved in lipopolysaccharide (LPS)-induced endothelial injury. The activation of Na(+)/H(+) exchanger (NHE) is responsible to increase intracellular Ca(2+) (Ca(i)(2+)) in cardiovascular diseases. Here we hypothesized that activation of NHE mediates LPS-induced endothelial cell apoptosis via calcium-dependent calpain pathway. Our results revealed that LPS-induced increases in NHE activity are dependent on NHE1 in human umbilical vein endothelial cells (HUVECs). Treatment of HUVECs with LPS increased the NHE1 activity in a time-dependent manner associated with the increased Ca(i)(2+), which resulted in enhanced calpain activity as well as HUVECs apoptosis via NHE1-dependent degradation of Bcl-2.
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Affiliation(s)
- Yuxi Zhao
- Key Laboratory for Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, People's Republic of China
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Apolipoprotein E-knockout mice show increased titers of serum anti-nuclear and anti-dsDNA antibodies. Biochem Biophys Res Commun 2012; 423:805-12. [PMID: 22713470 DOI: 10.1016/j.bbrc.2012.06.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 06/10/2012] [Indexed: 02/04/2023]
Abstract
Apolipoprotein E-knockout (ApoE(-/-)) mice, atherosclerosis-prone mice, show an autoimmune response, but the pathogenesis is not fully understood. We investigated the pathogenesis in female and male ApoE(-/-) mice. The spleens of all ApoE(-/-) and C57BL/6 (B6) mice were weighed. The serum IgG level and titers of anti-nuclear antibody (ANA) and anti-double-stranded DNA (anti-dsDNA) antibody were assayed by ELISA. Apoptosis of spleen tissue was evaluated by TUNEL. TLR4 level in spleen tissue was tested by immunohistochemistry and Western blot analysis. Levels of MyD88, p38, phosphorylated p38 (pp38), interferon regulatory factor 3 (IRF3) and Bcl-2-associated X protein (Bax) in spleen tissue were detected by Western blot analysis. We also survey the changes of serum autoantibodies, spleen weight, splenocyte apoptosis and the expressions of TLR4, MyD88, pp38, IRF3 and Bax in spleen tissue in male ApoE(-/-) mice after 4weeks of lipopolysaccharide (LPS), Toll-like receptor 4 ligand, administration. ApoE(-/-) mice showed splenomegaly and significantly increased serum level of IgG and titers of ANA and anti-dsDNA antibody as compared with B6 mice. Splenocyte apoptosis and the expression of TLR4, MyD88, pp38, IRF3 and Bax in spleen tissue were significantly lower in ApoE(-/-) than B6 mice. The expression of TLR4, MyD88, IRF3, pp38, and Bax differed by sex in ApoE(-/-) spleen tissue. The down-regulation of TLR4 signal molecules induced by LPS led to decreased expression of Bax and increased serum titers of ANA and anti-dsDNA antibody. Therefore, the TLR4 signal pathway may participate in maintaining the balance of splenocyte apoptosis and autoantibody production in ApoE(-/-) mice.
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Late repression of NF-κB activity by invasive but not non-invasive meningococcal isolates is required to display apoptosis of epithelial cells. PLoS Pathog 2011; 7:e1002403. [PMID: 22144896 PMCID: PMC3228807 DOI: 10.1371/journal.ppat.1002403] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 10/11/2011] [Indexed: 01/24/2023] Open
Abstract
Meningococcal invasive isolates of the ST-11 clonal complex are most frequently associated with disease and rarely found in carriers. Unlike carriage isolates, invasive isolates induce apoptosis in epithelial cells through the TNF-α signaling pathway. While invasive and non-invasive isolates are both able to trigger the TLR4/MyD88 pathway in lipooligosaccharide (LOS)-dependant manner, we show that only non-invasive isolates were able to induce sustained NF-κB activity in infected epithelial cells. ST-11 invasive isolates initially triggered a strong NF-κB activity in infected epithelial cells that was abolished after 9 h of infection and was associated with sustained activation of JNK, increased levels of membrane TNFR1, and induction of apoptosis. In contrast, infection with carriage isolates lead to prolonged activation of NF-κB that was associated with a transient activation of JNK increased TACE/ADAM17-mediated shedding of TNFR1 and protection against apoptosis. Our data provide insights to understand the meningococcal duality between invasiveness and asymptomatic carriage.
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Tamura R, Kanda T, Imazeki F, Wu S, Nakamoto S, Tanaka T, Arai M, Fujiwara K, Saito K, Roger T, Wakita T, Shirasawa H, Yokosuka O. Hepatitis C Virus nonstructural 5A protein inhibits lipopolysaccharide-mediated apoptosis of hepatocytes by decreasing expression of Toll-like receptor 4. J Infect Dis 2011; 204:793-801. [PMID: 21844306 DOI: 10.1093/infdis/jir381] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) has been shown to modulate multiple cellular processes, including apoptosis. The aim of this study was to assess the effects of HCV NS5A on apoptosis induced by Toll-like receptor (TLR) 4 ligand, lipopolysaccharide (LPS). METHODS Apoptotic responses to TLR4 ligands and the expression of molecules involved in TLR signaling pathways in human hepatocytes were examined with or without expression of HCV NS5A. RESULTS HCV NS5A protected HepG2 hepatocytes against LPS-induced apoptosis, an effect linked to reduced TLR4 expression. A similar downregulation of TLR4 expression was observed in Huh-7-expressing genotype 1b and 2a. In agreement with these findings, NS5A inhibited the expression of numerous genes encoding for molecules involved in TLR4 signaling, such as CD14, MD-2, myeloid differentiation primary response gene 88, interferon regulatory factor 3, and nuclear factor-κB2. Consistent with a conferred prosurvival advantage, NS5A diminished the poly(adenosine diphosphate-ribose) polymerase cleavage and the activation of caspases 3, 7, 8, and 9 and increased the expression of anti-apoptotic molecules Bcl-2 and c-FLIP. CONCLUSIONS HCV NS5A downregulates TLR4 signaling and LPS-induced apoptotic pathways in human hepatocytes, suggesting that disruption of TLR4-mediated apoptosis may play a role in the pathogenesis of HCV infection.
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Affiliation(s)
- Ryo Tamura
- Department of Medicine and Clinical Oncology, Chiba University, Graduate School of Medicine, Japan
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Langford MP, McGee DJ, Ta KH, Redens TB, Texada DE. Multiple caspases mediate acute renal cell apoptosis induced by bacterial cell wall components. Ren Fail 2011; 33:192-206. [PMID: 21332342 DOI: 10.3109/0886022x.2011.553304] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The stimulus for caspase-mediated renal cell apoptosis in septic acute renal failure (ARF) is unclear. To demonstrate the nephrotoxic effects of bacterial cell wall components, the anti-cellular activity of bacterial muropeptides (muramyl dipeptides), peptidoglycans, and lipopolysaccharides was investigated in rabbit kidney cells. Changes in the cell membrane (APOPercentage™ dye uptake), caspase activities, and DNA degradation were quantified colorimetrically and using densitometric assays and their inhibition by caspase-specific and pan-caspase inhibitors was determined. The onset and levels of APOPercentage™ dye-positive rabbit kidney cells, caspase activities, and DNA degradation were closely associated. Specific caspase-1, -2, -3, -4, -8, -10, and -12 inhibitors reduced caspase-3 activity by ≥40%, but only caspase-3 and -8-specific inhibitors reduced apoptotic DNA levels. Pan-caspase inhibitor Q-VD-OPh was 10-fold more effective at inhibiting rabbit kidney cell death, caspase activation, and DNA degradation than caspase-family inhibitor Z-VAD-FMK. Apoptosis was inhibited effectively by both pan-caspase inhibitors when applied early during the stimulus-to-response period. Multiple initiator and effector caspases were activated suggesting extrinsic, intrinsic, and endoplasmic reticulum/stress apoptotic pathway stimulation in rabbit kidney cells treated with bacterial cell wall components. The results provide in vitro support for bacterial cell wall-induced apoptosis as a pathogenic mechanism of renal cell death in septic ARF and support the potential prophylactic use of pan-caspase inhibitors to suppress septic ARF.
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Affiliation(s)
- Marlyn P Langford
- Department of Ophthalmology, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA.
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Innate Immunity and Host Defense against Microbial Infection. Mol Microbiol 2011. [DOI: 10.1128/9781555816834.ch54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hofmann U, Ertl G, Frantz S. Toll-like receptors as potential therapeutic targets in cardiac dysfunction. Expert Opin Ther Targets 2011; 15:753-65. [PMID: 21385118 DOI: 10.1517/14728222.2011.566560] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION The innate immune system can detect the highly conserved, relatively invariant structural motifs of pathogens. The most important innate immune receptors, Toll-like receptors (TLRs), represent a first line of defense against infectious pathogens, and play a pivotal role in initiating and shaping innate and adaptive immune responses. TLRs are not only expressed in immune cells, but also in cardiovascular cells. In addition to their role in response to microbial infections, evidence suggests that TLRs can also recognize endogenous ligands and may play a role in mediating cardiomyocyte cell death and survival after non-infectious injury. AREAS COVERED TLRs could be a link between cardiovascular diseases and the immune system. Experimentally, there is good evidence that TLR activation contributes to development and progression of both acute cardiac injury and chronic heart failure. The role of TLRs in myocardial ischemia-reperfusion, remodeling, septic cardiomyoparthy, autoimmune- and viral myocarditis, anthracycline-induced cardiomyopathy and cardiac hypertrophy, in basic as well as clinical science are discussed. EXPERT OPINION Evidence, mainly from animal experiments, indicates that TLRs contribute to all of the myocardial disease states reviewed in this paper. However, the relevance of TLRs as therapeutic targets remains to be defined as clinical data is sparse.
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Affiliation(s)
- Ulrich Hofmann
- University Hospital Würzburg, Department of Internal Medicine I, Oberdürrbacherstraße 6, 97080 Würzburg, Germany
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Harada K, Hide I, Seki T, Tanaka S, Nakata Y, Sakai N. Extracellular ATP differentially modulates Toll-like receptor 4-mediated cell survival and death of microglia. J Neurochem 2011; 116:1138-47. [PMID: 21210814 DOI: 10.1111/j.1471-4159.2011.07170.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The survival and death rates of inflammatory cells directly control their number and are substantially associated with the degree of inflammation. Microglia, key players in neuroinflammation, often cause excessive reactions implicated in neurological diseases. However, the mechanisms that determine microglial fate under pathological conditions remain to be elucidated. Here, we report that activation by lipopolysaccharide (LPS, a Toll-like receptor 4 ligand), an inflammation inducer, primarily promotes survival of microglia, but as its concentration is increased it induces cell death, resulting in decreased cell number. Moreover, extracellular ATP, which is released upon tissue damage, further enhanced the survival induced by a low LPS concentration and the death induced by a high LPS concentration. The survival-promoting effect of ATP was mimicked by non-hydrolyzable ATP analog, adenosine 5'-O-(3-thiotriphosphate), and also by the P2X(7) receptor agonist, 2'(3')-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate, and was suppressed by the P2X(7) antagonists, Brilliant Blue G and A 438079. On the contrary, the death of LPS-activated microglia was not affected by adenosine 5'-O-(3-thiotriphosphate), but enhanced by adenosine, ATP breakdown product. Thus, extracellular ATP modulates microglial survival and death in different ways involving P2X(7) receptor activation and ATP degradation to adenosine, respectively. Such Toll-like receptor 4/purinergic signaling may provide a fine regulatory system of neuroinflammation through modulating the microglial cell number.
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Affiliation(s)
- Kana Harada
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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Li JH, D'Alessio A, Pober JS. Lipopolysaccharide can trigger a cathepsin B-dependent programmed death response in human endothelial cells. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:1124-35. [PMID: 19661440 DOI: 10.2353/ajpath.2009.090113] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this study, we examined the mechanisms that contribute to lipopolysaccharide (LPS)-induced death responses in cultured human umbilical vein endothelial cells (HUVECs). In the presence of the protein synthesis inhibitor cycloheximide, LPS primarily induces caspase-dependent apoptotic cell death of HUVECs, which is blocked by siRNA-mediated knockdown of myeloid differentiation factor 88 adaptor protein but not of Toll-like receptor-associated interferon-inducing factor. Knockdown of Fas-associated death domain protein (FADD) by either siRNA or overexpression of a truncated version of FADD that lacks the N-terminal death effector domain (FADD(DN)) increases the sensitivity of HUVECs to LPS plus cycloheximide-mediated death. However, based on the use of proteinase inhibitors, cell death changes from being principally caspase-dependent to being principally cathepsin B (Cat B)-dependent. Knockdown of cellular FLICE inhibitory protein potentiates the caspase-dependent pathway but does not activate the Cat B-dependent death response. Knockdown of either myeloid differentiation factor 88 or Toll-like receptor-associated interferon-inducing factor expression does not affect the LPS-triggered Cat B death response in FADD-deficient HUVECs. Finally, in the presence of either the phosphatidylinositol 3 kinase inhibitor LY294002 or the inflammatory cytokine interferon-gamma, LPS activates both caspase- and Cat B-dependent death pathways. We conclude that LPS can activate a Cat-B-dependent programmed death response in human endothelial cells that is independent of both myeloid differentiation factor 88 and Toll-like receptor-associated interferon-inducing factor, is blocked by both FADD and phosphatidylinositol 3 kinase, and is potentiated by interferon-gamma.
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Affiliation(s)
- Jie H Li
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520-8089, USA
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Shioiri T, Muroi M, Hatao F, Nishida M, Ogawa T, Mimura Y, Seto Y, Kaminishi M, Tanamoto KI. Caspase-3 is activated and rapidly released from human umbilical vein endothelial cells in response to lipopolysaccharide. Biochim Biophys Acta Mol Basis Dis 2009; 1792:1011-8. [PMID: 19559790 DOI: 10.1016/j.bbadis.2009.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 12/25/2022]
Abstract
Endothelial cell injury/dysfunction is considered to play a critical role in the pathogenesis of severe sepsis and septic shock. Although it is considered that endothelial cell apoptosis is involved in endothelial injury/dysfunction, physiological involvement remains ambiguous since the induction of apoptosis requires the inhibition of endogenous apoptosis inhibitors. Here we show that caspase-3 activation, a biological indicator of apoptosis, is observed in response to lipopolysaccharide (LPS) stimulation even under the influence of endogenous apoptosis inhibitors, and that activated caspase-3 is rapidly released from human umbilical vein endothelial cells (HUVEC). In the presence of cycloheximide (CHX), an increase in intracellular caspase-3/7 activity in response to LPS was not detected in HUVEC up to 24 h following stimulation even in the presence of LPS-binding protein (LBP), soluble CD14 and soluble MD-2, whereas the decrease in cell viability and increase in release of the cellular enzyme lactate dehydrogenase (LDH) were observed in a soluble CD14/LBP-dependent manner. On the other hand, even in the absence of CHX, a significant increase in caspase-3/7 activity and a cleaved caspase-3 fragment with a slight increase in LDH release was observed in culture supernatants in response to LPS. This increase in caspase-3/7 activity was observed even when LDH release was undetected. These results indicate that caspase-3 is activated by LPS under physiological conditions and suggest that HUVEC escape from cell death by rapidly releasing activated caspase-3 into extracellular space. Failure of this escape mechanism may result in endothelial injury/dysfunction.
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Affiliation(s)
- Toshikazu Shioiri
- Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo 202-8585, Japan
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Karahashi H, Michelsen KS, Arditi M. Lipopolysaccharide-induced apoptosis in transformed bovine brain endothelial cells and human dermal microvessel endothelial cells: the role of JNK. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 182:7280-6. [PMID: 19454725 PMCID: PMC3057198 DOI: 10.4049/jimmunol.0801376] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Stimulation of transformed bovine brain endothelial cells (TBBEC) with LPS leads to apoptosis while human microvessel endothelial cells (HMEC) need the presence of cycloheximide (CHX) with LPS to induce apoptosis. To investigate the molecular mechanism of LPS-induced apoptosis in HMEC or TBBEC, we analyzed the involvement of MAPK and PI3K in TBBEC and HMEC. LPS-induced apoptosis in TBBEC was hallmarked by the activation of caspase 3, caspase 6, and caspase 8 after the stimulation of LPS, followed by poly(ADP-ribose) polymerase cleavage and lactate dehydrogenase release. We also observed DNA cleavage determined by TUNEL staining in TBBEC treated with LPS. Herbimycin A, a tyrosine kinase inhibitor, and SP600125, a JNK inhibitor, suppressed the activation of caspases and lactate dehydrogenase release. Moreover, a PI3K inhibitor (LY294002) suppressed activation of caspases and combined treatment with both SP600125 and LY294002 completely inhibited the activation of caspases. These results suggest that the JNK signaling pathway through the tyrosine kinase and PI3K pathways is involved in the induction of apoptosis in LPS-treated TBBEC. On the other hand, we observed sustained JNK activation in HMEC treated with LPS and CHX, and neither ERK1/2 nor AKT were activated. The addition of SP600125 suppressed phosphorylation of JNK and the activation of caspase 3 in HMEC treated with LPS and CHX. These results suggest that JNK plays an important role in the induction of apoptosis in endothelial cells.
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Affiliation(s)
- Hisae Karahashi
- Division of Pediatrics Infectious Diseases and Immunology and Immunobiology Research Institute, Cedars-Sinai Medical Center, David Geffen School of Medicine at the University of California Los Angeles, USA
| | - Kathrin S. Michelsen
- Division of Pediatrics Infectious Diseases and Immunology and Immunobiology Research Institute, Cedars-Sinai Medical Center, David Geffen School of Medicine at the University of California Los Angeles, USA
| | - Moshe Arditi
- Division of Pediatrics Infectious Diseases and Immunology and Immunobiology Research Institute, Cedars-Sinai Medical Center, David Geffen School of Medicine at the University of California Los Angeles, USA
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Albrecht EA, Sarma JV, Ward PA. Activation by C5a of endothelial cell caspase 8 and cFLIP. Inflamm Res 2009; 58:30-7. [PMID: 19115040 DOI: 10.1007/s00011-008-8156-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES AND DESIGN In this study, we examine the relationship between C5a and activation of cysteine aspartic acid protease 8 (caspase 8) in human umbilical vein endothelial cells (HUVEC). MATERIALS OR SUBJECTS Primary cultures of HUVEC were used. TREATMENTS Recombinant human C5a (50 ng/ml) was used in the presence or absence of 10 microg/ml cycloheximide (CHX). METHODS HUVEC were treated with C5a alone and in the presence of CHX, then monitored for cell viability, poly- ADP-ribose 1 (PARP-1) and caspase 8 activities. Gene and protein expressions were assessed for caspase 8 and the caspase 8 homologue, FLICE -inhibitory protein (cFLIP). RESULTS We found a 43.1 +/- 6.9 percent reduction in viability of HUVEC stimulated for 18 h with 50 ng/ml C5a in the presence of 10 microg/ml CHX (p < 0.05). In contrast, the cell viability of cells stimulated for 18 h with 50 ng/ml C5a or 10 microg/ml CHX alone was not significantly different compared to the non-stimulated control. Treatment of HUVEC with C5a induced an increase in caspase 8 activity but did not significantly affect cFLIP levels. CONCLUSIONS These data suggest caspase 8 activation induced by C5a leads to cell death if protein synthesis of antiapoptotic protein(s) is blocked.
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Affiliation(s)
- E A Albrecht
- Department of Biology and Physics, Kennesaw State University, Kennesaw, GA 30144, USA
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Chao W. Toll-like receptor signaling: a critical modulator of cell survival and ischemic injury in the heart. Am J Physiol Heart Circ Physiol 2008; 296:H1-12. [PMID: 19011041 DOI: 10.1152/ajpheart.00995.2008] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Toll-like receptors (TLRs) represent the first line of host defense against microbial infection and play a pivotal role in both innate and adaptive immunity. TLRs recognize invading pathogens through molecular pattern recognition, transduce signals via distinct intracellular pathways involving a unique set of adaptor proteins and kinases, and ultimately lead to the activation of transcription factors and inflammatory responses. Among 10 TLRs identified in humans, at least two exist in the heart, i.e., TLR2 and TLR4. In addition to the critical role of these in mediating cardiac dysfunction in septic conditions, emerging evidence suggests that the TLRs can also recognize endogenous ligands and may play an important role in modulating cardiomyocyte survival and in ischemic myocardial injury. In animal models of ischemia-reperfusion injury or in hypoxic cardiomyocytes in vitro, the administration of a sublethal dose of lipopolysaccharide, which signals through TLR4, reduces subsequent myocardial infarction, improves cardiac functions, and attenuates cardiomyocyte apoptosis. By contrast, a systemic deficiency of TLR2, TLR4, or myeloid differentiation primary-response gene 88, an adaptor critical for all TLR signaling, except TLR3, leads to an attenuated myocardial inflammation, a smaller infarction size, a better preserved ventricular function, and a reduced ventricular remodeling after ischemic injury. These loss-of-function studies suggest that both TLRs contribute to myocardial inflammation and ischemic injury in the heart although the exact contribution of cardiac (vs. circulatory cell) TLRs remains to be defined. These recent studies demonstrate an emerging role for TLRs as a critical modulator in both cell survival and tissue injury in the heart.
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Affiliation(s)
- Wei Chao
- Dept. of Anesthesia & Critical Care, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA.
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Cates EA, Connor EE, Mosser DM, Bannerman DD. Functional characterization of bovine TIRAP and MyD88 in mediating bacterial lipopolysaccharide-induced endothelial NF-kappaB activation and apoptosis. Comp Immunol Microbiol Infect Dis 2008; 32:477-90. [PMID: 18760477 DOI: 10.1016/j.cimid.2008.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2008] [Indexed: 02/07/2023]
Abstract
Mastitis is a prevalent disease in dairy cows. Gram-negative bacteria, which express the pro-inflammatory molecule lipopolysaccharide (LPS), are responsible for the majority of acute clinical cases of mastitis. Previous studies have identified differential susceptibility of human and bovine endothelial cells (EC) to the pro-inflammatory and injury-inducing effects of LPS. The Toll-like receptor (TLR)-4 signaling pathway, which is activated by LPS, has been well studied in humans, but not in ruminants. Human myeloid differentiation-factor 88 (MyD88) and TIR-domain containing adaptor protein (TIRAP) are critical proteins in the LPS-induced NF-kappaB and apoptotic signaling pathways. To assess the role of the bovine orthologs of these proteins in bovine TLR-4 signaling, dominant-negative constructs were expressed in bovine EC, and LPS-induced NF-kappaB activation and apoptosis evaluated. The results from this study indicate that bovine MyD88 and TIRAP play functional roles in transducing LPS signaling from TLR-4 to downstream effector molecules involved in NF-kappaB activation, and that TIRAP promotes apoptotic signaling.
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Affiliation(s)
- Elizabeth A Cates
- Bovine Functional Genomics Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA
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