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Qian G, Morral N. Role of non-coding RNAs on liver metabolism and NAFLD pathogenesis. Hum Mol Genet 2022; 31:R4-R21. [PMID: 35417923 DOI: 10.1093/hmg/ddac088] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/22/2022] [Accepted: 04/08/2022] [Indexed: 11/14/2022] Open
Abstract
Obesity and type 2 diabetes are major contributors to the growing prevalence of non-alcoholic fatty liver disease (NAFLD), a chronic liver condition characterized by accumulation of fat in individuals without a significant amount of alcohol intake. The NAFLD spectrum ranges from simple steatosis (early stages, known as NAFL), to non-alcoholic steatohepatitis (NASH), which can progress to fibrosis and cirrhosis or hepatocellular carcinoma. Obesity, type 2 diabetes, and NAFLD are strongly associated with insulin resistance. In the liver, insulin resistance increases hepatic glucose output, lipogenesis, and VLDL secretion, leading to a combination of hyperglycemia and hypertriglyceridemia. Aberrant gene expression is a hallmark of insulin resistance. Non-coding RNAs (ncRNAs) have emerged as prominent regulators of gene expression that operate at the transcriptional, post-transcriptional, and post-translational levels. In the last couple of decades a wealth of studies have provided evidence that most processes of liver metabolism are orchestrated by ncRNAs. This review focuses on the role of microRNAs, long non-coding RNAs and circular RNAs as coordinators of hepatic function, as well as the current understanding on how their dysregulation contributes to abnormal metabolism and pathophysiology in animal models of insulin resistance and NAFLD. Moreover, ncRNAs are emerging as useful biomarkers that may be able to discriminate between the different stages of NAFLD. The potential of ncRNAs as therapeutic drugs for NAFLD treatment and as biomarkers is discussed.
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Affiliation(s)
- Gene Qian
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Núria Morral
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
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Nury T, Yammine A, Ghzaiel I, Sassi K, Zarrouk A, Brahmi F, Samadi M, Rup-Jacques S, Vervandier-Fasseur D, Pais de Barros J, Bergas V, Ghosh S, Majeed M, Pande A, Atanasov A, Hammami S, Hammami M, Mackrill J, Nasser B, Andreoletti P, Cherkaoui-Malki M, Vejux A, Lizard G. Attenuation of 7-ketocholesterol- and 7β-hydroxycholesterol-induced oxiapoptophagy by nutrients, synthetic molecules and oils: Potential for the prevention of age-related diseases. Ageing Res Rev 2021; 68:101324. [PMID: 33774195 DOI: 10.1016/j.arr.2021.101324] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/10/2021] [Accepted: 03/12/2021] [Indexed: 12/18/2022]
Abstract
Age-related diseases for which there are no effective treatments include cardiovascular diseases; neurodegenerative diseases such as Alzheimer's disease; eye disorders such as cataract and age-related macular degeneration; and, more recently, Severe Acute Respiratory Syndrome (SARS-CoV-2). These diseases are associated with plasma and/or tissue increases in cholesterol derivatives mainly formed by auto-oxidation: 7-ketocholesterol, also known as 7-oxo-cholesterol, and 7β-hydroxycholesterol. The formation of these oxysterols can be considered as a consequence of mitochondrial and peroxisomal dysfunction, leading to increased in oxidative stress, which is accentuated with age. 7-ketocholesterol and 7β-hydroxycholesterol cause a specific form of cytotoxic activity defined as oxiapoptophagy, including oxidative stress and induction of death by apoptosis associated with autophagic criteria. Oxiaptophagy is associated with organelle dysfunction and in particular with mitochondrial and peroxisomal alterations involved in the induction of cell death and in the rupture of redox balance. As the criteria characterizing 7-ketocholesterol- and 7β-hydroxycholesterol-induced cytotoxicity are often simultaneously observed in major age-related diseases (cardiovascular diseases, age-related macular degeneration, Alzheimer's disease) the involvement of these oxysterols in the pathophysiology of the latter seems increasingly likely. It is therefore important to better understand the signalling pathways associated with the toxicity of 7-ketocholesterol and 7β-hydroxycholesterol in order to identify pharmacological targets, nutrients and synthetic molecules attenuating or inhibiting the cytotoxic activities of these oxysterols. Numerous natural cytoprotective compounds have been identified: vitamins, fatty acids, polyphenols, terpenes, vegetal pigments, antioxidants, mixtures of compounds (oils, plant extracts) and bacterial enzymes. However, few synthetic molecules are able to prevent 7-ketocholesterol- and/or 7β-hydroxycholesterol-induced cytotoxicity: dimethyl fumarate, monomethyl fumarate, the tyrosine kinase inhibitor AG126, memantine, simvastatine, Trolox, dimethylsufoxide, mangafodipir and mitochondrial permeability transition pore (MPTP) inhibitors. The effectiveness of these compounds, several of which are already in use in humans, makes it possible to consider using them for the treatment of certain age-related diseases associated with increased plasma and/or tissue levels of 7-ketocholesterol and/or 7β-hydroxycholesterol.
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Al Dubayee M, Alshahrani A, Aljada D, Zahra M, Alotaibi A, Ababtain I, Alnaim M, Alahmari A, Aljarallah A, Elahi MA, Fakhoury HMA. Gene Expression Profiling of Apoptotic Proteins in Circulating Peripheral Blood Mononuclear Cells in Type II Diabetes Mellitus and Modulation by Metformin. Diabetes Metab Syndr Obes 2021; 14:1129-1139. [PMID: 33758522 PMCID: PMC7979348 DOI: 10.2147/dmso.s300048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 02/23/2021] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Insulin resistance in obesity and type 2 diabetes mellitus (T2DM) is associated with cardiovascular complications such as atherosclerosis. On the other hand, the reduction of apoptosis in macrophages has been linked with accelerated atherosclerosis. Apoptosis is controlled by a different family of proteins including Bcl-2 and caspases. METHODS To examine apoptosis in insulin resistance, we assessed the mRNA expression by qRT-PCR of several Bcl-2 family members, as well as caspase-3, -7, -8, and -9 in peripheral blood mononuclear cells (PBMCs) isolated from lean, obese, diabetic, and diabetic on metformin individuals. RESULTS PBMCs of diabetic individuals exhibited reduced expression of caspase-7 and increased expression of Bcl-10, Bad, Bax, Bid, and caspase-3. T2DM on metformin group had significantly higher Bad, Bax, and caspase-7 expression. DISCUSSION The moderate up-regulation of pro-apoptotic Bcl-10, Bax, Bad, Bid, and the effector caspase-3 coupled with inhibition of caspase-7 in circulating PBMCs of T2DM could be the result of increased inflammation in T2DM. Metformin treatment significantly inhibited the expression of Bcl-10, Bid, and caspase-3 and upregulated Bad/Bax/caspase-7 pathway suggesting the activation of Bad/Bax/caspase-7 apoptotic pathway. Further studies are warranted to elicit the underlying apoptotic pathways of PBMCs in T2DM and following metformin treatment.
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Affiliation(s)
- Mohammed Al Dubayee
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia
- Department of Medicine, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
- Correspondence: Mohammed Al Dubayee College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), P.O. Box 22490, Riyadh, Saudi ArabiaTel +966 11 801 1111 ext: 53551 Email
| | - Awad Alshahrani
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia
- Department of Medicine, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Dana Aljada
- College of Liberal Arts and Sciences, Hofstra University, Hempstead, NY, USA
| | - Mahmoud Zahra
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Ahmed Alotaibi
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
| | - Ibrahim Ababtain
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
| | - Malik Alnaim
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
| | - Ali Alahmari
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
| | - Abdullah Aljarallah
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia
| | - Muhammad Affan Elahi
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hana M A Fakhoury
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Vejux A, Abed-Vieillard D, Hajji K, Zarrouk A, Mackrill JJ, Ghosh S, Nury T, Yammine A, Zaibi M, Mihoubi W, Bouchab H, Nasser B, Grosjean Y, Lizard G. 7-Ketocholesterol and 7β-hydroxycholesterol: In vitro and animal models used to characterize their activities and to identify molecules preventing their toxicity. Biochem Pharmacol 2020; 173:113648. [DOI: 10.1016/j.bcp.2019.113648] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/30/2019] [Indexed: 12/17/2022]
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Lu J, Chen X, Xu X, Liu J, Zhang Z, Wang M, Li X, Chen H, Zhao D, Wang J, Zhao D, Cong D, Li X, Sun L. Active polypeptides from Hirudo inhibit endothelial cell inflammation and macrophage foam cell formation by regulating the LOX-1/LXR-α/ABCA1 pathway. Biomed Pharmacother 2019; 115:108840. [DOI: 10.1016/j.biopha.2019.108840] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/28/2019] [Accepted: 03/31/2019] [Indexed: 12/31/2022] Open
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The Oxysterol 25-Hydroxycholesterol Inhibits Replication of Murine Norovirus. Viruses 2019; 11:v11020097. [PMID: 30682775 PMCID: PMC6409565 DOI: 10.3390/v11020097] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 01/08/2023] Open
Abstract
Cholesterol, an essential component of mammalian cells, is also an important factor in the replicative-cycles of several human and animal viruses. The oxysterol, 25-hydroxycholesterol, is produced from cholesterol by the enzyme, cholesterol 25-hydroxylase. 25-hydroxycholesterol (25-HC) has been shown to have anti-viral activities against a wide range of viruses, including a range of positive-sense RNA viruses. In this study, we have investigated the role of 25-HC in norovirus replication using murine norovirus (MNV) as a model system. As a control, we employed herpes simplex virus-1 (HSV-1), a pathogen previously shown to be inhibited by 25-HC. Consistent with previous studies, 25-HC inhibited HSV-1 replication in the MNV-susceptible cell line, RAW264.7. Treating RAW264.7 cells with sub-cytotoxic concentrations of 25-HC reduced the MNV titers. However, other sterols such as cholesterol or the oxysterol, 22-S-hydroxycholesterol (22-S-HC), did not inhibit MNV replication. Moreover, treating MNV-infected RAW264.7 cells with 25-HC-stimulated caspase 3/7 activity, which leads to enhanced apoptosis and increased cell death. Our study adds noroviruses to the list of viruses inhibited by 25-HC and begins to offer insights into the mechanism behind this inhibition.
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Brahmi F, Vejux A, Sghaier R, Zarrouk A, Nury T, Meddeb W, Rezig L, Namsi A, Sassi K, Yammine A, Badreddine I, Vervandier-Fasseur D, Madani K, Boulekbache-Makhlouf L, Nasser B, Lizard G. Prevention of 7-ketocholesterol-induced side effects by natural compounds. Crit Rev Food Sci Nutr 2018; 59:3179-3198. [DOI: 10.1080/10408398.2018.1491828] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Fatiha Brahmi
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab. Biomathématique, Biochimie, Biophysique et Scientométrie, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia, Algeria
| | - Anne Vejux
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
| | - Randa Sghaier
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab-NAFS ‘Nutrition - Functional Food & Vascular Health’, LR12ES05, Université de Monastir, Monastir, Tunisia
- Faculty of Medicine, Lab. Biochemistry, Sousse, Tunisia
| | - Amira Zarrouk
- Lab-NAFS ‘Nutrition - Functional Food & Vascular Health’, LR12ES05, Université de Monastir, Monastir, Tunisia
- Faculty of Medicine, Lab. Biochemistry, Sousse, Tunisia
| | - Thomas Nury
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
| | - Wiem Meddeb
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- LMMA/IPEST, Faculty of Science, University of Carthage, Bizerte, Tunisia
| | - Leila Rezig
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- ESIAT, Lab. Conservation et Valorisation des Aliments, Tunis, Tunisia
| | - Amira Namsi
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- University Tunis El Manar, Faculty of Science of Tunis, Laboratory of Functional Neurophysiology and Pathology, Tunis, Tunisia
| | - Khouloud Sassi
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab. Onco-Hematology, Faculty de Medicine of Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Aline Yammine
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Bioactive Molecules Research Lab, Faculty of Sciences, Lebanese University, Beirut, Lebanon
| | - Iham Badreddine
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
- Lab. ‘Valorisation des Ressources Naturelles et Environnement’, Université Ibn Zohr, Taroudant, Morocco
| | | | - Khodir Madani
- Lab. Biomathématique, Biochimie, Biophysique et Scientométrie, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia, Algeria
| | - Lila Boulekbache-Makhlouf
- Lab. Biomathématique, Biochimie, Biophysique et Scientométrie, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia, Algeria
| | - Boubker Nasser
- Lab. Neuroscience and Biochemistry, Université Hassan 1er, Settat, Morocco
| | - Gérard Lizard
- Team ‘Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism’, Lab. Bio-PeroxIL, Université de Bourgogne Franche-Comté, Dijon, France
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Nury T, Sghaier R, Zarrouk A, Ménétrier F, Uzun T, Leoni V, Caccia C, Meddeb W, Namsi A, Sassi K, Mihoubi W, Riedinger JM, Cherkaoui-Malki M, Moreau T, Vejux A, Lizard G. Induction of peroxisomal changes in oligodendrocytes treated with 7-ketocholesterol: Attenuation by α-tocopherol. Biochimie 2018; 153:181-202. [PMID: 30031877 DOI: 10.1016/j.biochi.2018.07.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/17/2018] [Indexed: 02/08/2023]
Abstract
The involvement of organelles in cell death is well established especially for endoplasmic reticulum, lysosomes and mitochondria. However, the role of the peroxisome is not well known, though peroxisomal dysfunction favors a rupture of redox equilibrium. To study the role of peroxisomes in cell death, 158 N murine oligodendrocytes were treated with 7-ketocholesterol (7 KC: 25-50 μM, 24 h). The highest concentration is known to induce oxiapoptophagy (OXIdative stress + APOPTOsis + autoPHAGY), whereas the lowest concentration does not induce cell death. In those conditions (with 7 KC: 50 μM) morphological, topographical and functional peroxisome alterations associated with modifications of the cytoplasmic distribution of mitochondria, with mitochondrial dysfunction (loss of transmembrane mitochondrial potential, decreased level of cardiolipins) and oxidative stress were observed: presence of peroxisomes with abnormal sizes and shapes similar to those observed in Zellweger fibroblasts, lower cellular level of ABCD3, used as a marker of peroxisomal mass, measured by flow cytometry, lower mRNA and protein levels (measured by RT-qPCR and western blotting) of ABCD1 and ABCD3 (two ATP-dependent peroxisomal transporters), and of ACOX1 and MFP2 enzymes, and lower mRNA level of DHAPAT, involved in peroxisomal β-oxidation and plasmalogen synthesis, respectively, and increased levels of very long chain fatty acids (VLCFA: C24:0, C24:1, C26:0 and C26:1, quantified by gas chromatography coupled with mass spectrometry) metabolized by peroxisomal β-oxidation. In the presence of 7 KC (25 μM), slight mitochondrial dysfunction and oxidative stress were found, and no induction of apoptosis was detected; however, modifications of the cytoplasmic distribution of mitochondria and clusters of mitochondria were detected. The peroxisomal alterations observed with 7 KC (25 μM) were similar to those with 7 KC (50 μM). In addition, data obtained by transmission electron microcopy and immunofluorescence microscopy by dual staining with antibodies raised against p62, involved in autophagy, and ABCD3, support that 7 KC (25-50 μM) induces pexophagy. 7 KC (25-50 μM)-induced side effects were attenuated by α-tocopherol but not by α-tocotrienol, whereas the anti-oxidant properties of these molecules determined with the FRAP assay were in the same range. These data provide evidences that 7 KC, at concentrations inducing or not cell death, triggers morphological, topographical and functional peroxisomal alterations associated with minor or major mitochondrial changes.
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Affiliation(s)
- Thomas Nury
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France
| | - Randa Sghaier
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France; Univ. Monastir, Lab. Biotechnology, Monastir, Tunisia
| | - Amira Zarrouk
- Univ. Monastir, Lab-NAFS 'Nutrition - Functional Food & Vascular Diseases' LR12-ES-05, Monastir, Tunisia; Faculty of Medicine, Sousse, Tunisia
| | | | - Tugba Uzun
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France
| | - Valerio Leoni
- Lab. Clinical Chemistry, Hospital of Varese, ASST-Settelaghi, Varese, Italy
| | - Claudio Caccia
- Unit of Medical Genetics and Neurogenetics, IRCCS Carlo Besta, Milano, Italy
| | - Wiem Meddeb
- Univ. Carthage, LMMA, IPEST, Tunis, and Fac. of Science of Bizerte, Bizerte, Tunisia
| | - Amira Namsi
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France; Univ. Tunis El Manar, Lab. Neurophysiologie Fonctionnelle et Pathologie-UR11ES/09, Tunis, Tunisia
| | - Khouloud Sassi
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France; Univ. Tunis El Manar, Fac. of Medicine, Lab of Onco-Hematology, Tunis, Tunisia
| | - Wafa Mihoubi
- Centre de Biotechnologie de Sfax, Lab. Biotechnologie Moléculaire des Eucaryotes, Sfax, Tunisia
| | - Jean-Marc Riedinger
- Centre de Lutte Contre le Cancer GF Leclerc, Laboratoire de Biologie Médicale, Dijon, France
| | - Mustapha Cherkaoui-Malki
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France
| | - Thibault Moreau
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France; Dept. of Neurology, Univ. Hospital of Dijon, France
| | - Anne Vejux
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France
| | - Gérard Lizard
- Univ. Bourgogne Franche-Comté, Lab. Bio-PeroxIL, 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism' (EA7270) / Inserm, Dijon, France.
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Zhang H, Liu Q, Lin JL, Wang Y, Zhang RX, Hou JB, Yu B. Recombinant Human Thioredoxin-1 Protects Macrophages from Oxidized Low-Density Lipoprotein-Induced Foam Cell Formation and Cell Apoptosis. Biomol Ther (Seoul) 2018; 26:121-129. [PMID: 28554199 PMCID: PMC5839490 DOI: 10.4062/biomolther.2016.275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 11/22/2022] Open
Abstract
Oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and apoptosis play critical roles in the pathogenesis of atherosclerosis. Thioredoxin-1 (Trx) is an antioxidant that potently protects various cells from oxidative stress-induced cell death. However, the protective effect of Trx on ox-LDL-induced macrophage foam cell formation and apoptosis has not been studied. This study aims to investigate the effect of recombinant human Trx (rhTrx) on ox-LDL-stimulated RAW264.7 macrophages and elucidate the possible mechanisms. RhTrx significantly inhibited ox-LDL-induced cholesterol accumulation and apoptosis in RAW264.7 macrophages. RhTrx also suppressed the ox-LDL-induced overproduction of lectin-like oxidized LDL receptor (LOX-1), Bax and activated caspase-3, but it increased the expression of Bcl-2. In addition, rhTrx markedly inhibited the ox-LDL-induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38 mitogen-activated protein kinases (MAPK). Furthermore, anisomycin (a p38 MAPK activator) abolished the protective effect of rhTrx on ox-LDL-stimulated RAW264.7 cells, and SB203580 (a p38 MAPK inhibitor) exerted a similar effect as rhTrx. Collectively, these findings indicate that rhTrx suppresses ox-LDL-stimulated foam cell formation and macrophage apoptosis by inhibiting ROS generation, p38 MAPK activation and LOX-1 expression. Therefore, we propose that rhTrx has therapeutic potential in the prevention and treatment of atherosclerosis.
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Affiliation(s)
- Hui Zhang
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Qi Liu
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Jia-Le Lin
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Yu Wang
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Ruo-Xi Zhang
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Jing-Bo Hou
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Bo Yu
- Department of Cardiology, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
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Shen C, Zhou J, Wang X, Yu XY, Liang C, Liu B, Pan X, Zhao Q, Song JL, Wang J, Bao M, Wu C, Li Y, Song YH. Angiotensin-II-induced Muscle Wasting is Mediated by 25-Hydroxycholesterol via GSK3β Signaling Pathway. EBioMedicine 2017; 16:238-250. [PMID: 28161398 PMCID: PMC5474518 DOI: 10.1016/j.ebiom.2017.01.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 01/20/2017] [Accepted: 01/27/2017] [Indexed: 12/14/2022] Open
Abstract
While angiotensin II (ang II) has been implicated in the pathogenesis of cardiac cachexia (CC), the molecules that mediate ang II's wasting effect have not been identified. It is known TNF-α level is increased in patients with CC, and TNF-α release is triggered by ang II. We therefore hypothesized that ang II induced muscle wasting is mediated by TNF-α. Ang II infusion led to skeletal muscle wasting in wild type (WT) but not in TNF alpha type 1 receptor knockout (TNFR1KO) mice, suggesting that ang II induced muscle loss is mediated by TNF-α through its type 1 receptor. Microarray analysis identified cholesterol 25-hydroxylase (Ch25h) as the down stream target of TNF-α. Intraperitoneal injection of 25-hydroxycholesterol (25-OHC), the product of Ch25h, resulted in muscle loss in C57BL/6 mice, accompanied by increased expression of atrogin-1, MuRF1 and suppression of IGF-1/Akt signaling pathway. The identification of 25-OHC as an inducer of muscle wasting has implications for the development of specific treatment strategies in preventing muscle loss. Ang II induced muscle wasting is mediated by TNF-α, which in turn up regulates Ch25h Knockout of TNFR1 inhibits the production of 25-OHC and blocks ang II induced muscle loss in mice 25-OHC injection induces muscle wasting in mice by activating GSK3β A GSK3β inhibitor blocks ang II induced muscle atrophy, which paves the way for targeted therapy to treat muscle wasting
Cardiac cachexia (CC), a condition characterized by weight loss and muscle wasting, is a serious complication that occurs in patients with chronic heart failure. This condition impairs patient's daily physical activity and their quality of life. Specific therapy for CC is currently unavailable because the pathogenesis remains unknown. Previous studies have identified angiotensin II (ang II) as an important mediator of CC. We now report a previously unrecognized role of 25-hydroxycholesterol (25-OHC) in mediating ang II induced muscle loss. The identification of 25-OHC as a muscle wasting inducer has implications for the development of therapeutic intervention in preserving muscle mass.
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Affiliation(s)
- Congcong Shen
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China
| | - Jin Zhou
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, PR China.
| | - Xiaoxiao Wang
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China
| | - Xi-Yong Yu
- Guangdong Cardiovascular Institute, Guangzhou Medical University, Guangzhou, Guangdong, PR China
| | - Chun Liang
- Department of Cardiology, Shanghai Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai, PR China
| | - Bin Liu
- Cardiovascular Disease Center, The First Hospital of Ji Lin University, Changchun, Jilin 130021, PR China
| | - Xiangbin Pan
- Department of Cardiac Surgery, Fuwai Hospital, PR China
| | - Qiong Zhao
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China
| | - Jenny Lee Song
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China
| | - Jiajun Wang
- Department of Gynecology, The Affiliated Maternity and Child Health Hospital of Nanjing Medical University, Wuxi, PR China
| | - Meiyu Bao
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China
| | - Chaofan Wu
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China
| | - Yangxin Li
- The Department of Cardiovascular Surgery of the First Affiliated Hospital and the Institute for Cardiovascular Science, Soochow University, Suzhou, Jiangsu 215123, PR China.
| | - Yao-Hua Song
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, PR China.
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11
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Rárová L, Steigerová J, Kvasnica M, Bartůněk P, Křížová K, Chodounská H, Kolář Z, Sedlák D, Oklestkova J, Strnad M. Structure activity relationship studies on cytotoxicity and the effects on steroid receptors of AB-functionalized cholestanes. J Steroid Biochem Mol Biol 2016; 159:154-69. [PMID: 26976651 DOI: 10.1016/j.jsbmb.2016.03.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 03/02/2016] [Accepted: 03/10/2016] [Indexed: 01/14/2023]
Abstract
Structure-activity relationship analysis and profiling of a library of AB-functionalized cholestane derivatives closely related to brassinosteroids (BRs) were performed to examine their antiproliferative activities and activities on steroid hormone receptors. Some of the compounds were found to have strong cytotoxic activity in several human normal and cancer cell lines. The presence of a 3-hydroxy or 3-oxo group and 2,3-vicinal diol or 3,4-vicinal diol moiety were found to be necessary for optimum biological activity, as well as a six-membered B ring. According to the profiling of all steroid receptors in both agonist and antagonist mode, the majority of the cholestanes were weakly active or inactive compared to the natural ligands. Estrogenic activity was detected for two compounds, two compounds possessed antagonistic properties on estrogen receptors and seven compounds showed agonistic activity. Two active cholestane derivatives were shown to strongly influence cell viability, proliferation, cell cycle distribution, apoptosis and molecular pathways responsible for these processes in hormone-sensitive/insensitive (MCF7/MDA-MB-468) breast cancer cell lines.
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Affiliation(s)
- Lucie Rárová
- Department of Chemical Biology and Genetics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic.
| | - Jana Steigerová
- Laboratory of Molecular Pathology, Institute of Clinical and Molecular Pathology, Faculty of Medicine, Palacký University, Hněvotínská 5, 77900 Olomouc, Czech Republic; Institute of Molecular and Translation Medicine, Faculty of Medicine and Dentistry, Palacký University and Faculty Hospital in Olomouc, Hněvotínská 5, 77900 Olomouc, Czech Republic.
| | - Miroslav Kvasnica
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic.
| | - Petr Bartůněk
- CZ-OPENSCREEN: National Infrastructure for Chemical Biology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Praha 4, Czech Republic.
| | - Kateřina Křížová
- Laboratory of Molecular Pathology, Institute of Clinical and Molecular Pathology, Faculty of Medicine, Palacký University, Hněvotínská 5, 77900 Olomouc, Czech Republic; Institute of Molecular and Translation Medicine, Faculty of Medicine and Dentistry, Palacký University and Faculty Hospital in Olomouc, Hněvotínská 5, 77900 Olomouc, Czech Republic.
| | - Hana Chodounská
- Institute of Organic Chemistry and Biochemistry of the Academy of Sciences of the Czech Republic, v.v.i, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
| | - Zdeněk Kolář
- Laboratory of Molecular Pathology, Institute of Clinical and Molecular Pathology, Faculty of Medicine, Palacký University, Hněvotínská 5, 77900 Olomouc, Czech Republic.
| | - David Sedlák
- CZ-OPENSCREEN: National Infrastructure for Chemical Biology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Praha 4, Czech Republic.
| | - Jana Oklestkova
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic.
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic.
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Apigenin Attenuates Atherogenesis through Inducing Macrophage Apoptosis via Inhibition of AKT Ser473 Phosphorylation and Downregulation of Plasminogen Activator Inhibitor-2. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:379538. [PMID: 25960827 PMCID: PMC4413885 DOI: 10.1155/2015/379538] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/24/2015] [Accepted: 03/24/2015] [Indexed: 01/07/2023]
Abstract
Macrophage survival is believed to be a contributing factor in the development of early atherosclerotic lesions. Dysregulated apoptosis of macrophages is involved in the inflammatory process of atherogenesis. Apigenin is a flavonoid that possesses various clinically relevant properties such as anti-inflammatory, antiplatelet, and antitumor activities. Here we showed that apigenin attenuated atherogenesis in apoE (-/-) mice in an in vivo test. In vitro experiments suggested that apigenin induced apoptosis of oxidized low density lipoprotein- (OxLDL-) loaded murine peritoneal macrophages (MPMs). Proteomic analysis showed that apigenin reduced the expression of plasminogen activator inhibitor 2 (PAI-2). PAI-2 has antiapoptotic effects in OxLDL-loaded MPMs. Enhancing PAI-2 expression significantly reduced the proapoptosis effects of apigenin. Molecular docking assay with AutoDock software predicted that residue Ser473 of Akt1 is a potential binding site for apigenin. Lentiviral-mediated overexpression of Akt1 wild type weakened the proapoptosis effect of apigenin in OxLDL-loaded MPMs. Collectively, apigenin executes its anti-atherogenic effects through inducing OxLDL-loaded MPMs apoptosis. The proapoptotic effects of apigenin were at least partly attributed to downregulation of PAI-2 through suppressing phosphorylation of AKT at Ser473.
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13
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Mollace V, Gliozzi M, Musolino V, Carresi C, Muscoli S, Mollace R, Tavernese A, Gratteri S, Palma E, Morabito C, Vitale C, Muscoli C, Fini M, Romeo F. Oxidized LDL attenuates protective autophagy and induces apoptotic cell death of endothelial cells: Role of oxidative stress and LOX-1 receptor expression. Int J Cardiol 2015; 184:152-158. [PMID: 25703423 DOI: 10.1016/j.ijcard.2015.02.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 02/03/2015] [Accepted: 02/07/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Overproduction of oxidized-low density lipoproteins (oxyLDLs) has been found to contribute in endothelial cell (EC) dysfunction thereby leading to atherosclerosis development and progression. In particular, oxyLDLs lead to apoptotic cell death of EC via oxidative stress production, mostly subsequent to the overexpression of the scavenger receptor LOX-1. Here, we hypothesize that LOX-1 expression in EC represents a crucial event which attenuates protective autophagic response, thereby enhancing programmed endothelial cell death. METHODS AND RESULTS Bovine aortic endothelial cells (BAECs) in culture were exposed to oxyLDL (1-100 μM). After 48 h incubation, oxyLDL produced pronounced malondialdehyde (MDA) elevation and apoptotic cell death of BAEC as detected by FACS analysis, an effect counteracted by antioxidant N-acetyl-cysteine (NAC) as well as by the NO-donor SNAP. OxyLDL-induced apoptotic cell death was also accompanied by reduced VEGF-dependent phosphorylation of constitutive NO synthase (cNOS) in BAEC and consistent attenuation of autophagic response as detected by the expression of Beclin-1 and LC3, two reliable biomarkers of autophagy. Moreover, silencing LOX-1 receptor significantly restored LC3 expression in oxyLDL-treated BAEC, thus suggesting a key role of LOX-1 overproduction in oxyLDL-induced endothelial dysfunction. CONCLUSIONS OxyLDL leads to impaired NO generation and apoptotic cell death in BAECs. This effect occurs via the overexpression of LOX-1 and subsequent attenuation of protective autophagic response thereby contributing to the pathophysiology of oxyLDL-induced endothelial dysfunction which characterizes early stages of atherosclerotic process.
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Affiliation(s)
- Vincenzo Mollace
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy; IRCCS San Raffaele, Rome, Italy.
| | - Micaela Gliozzi
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Vincenzo Musolino
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Cristina Carresi
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Saverio Muscoli
- Department of Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Rocco Mollace
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Annamaria Tavernese
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Santo Gratteri
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Ernesto Palma
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | - Chiara Morabito
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy
| | | | - Carolina Muscoli
- IRC-FSH Department of Health Sciences, University "Magna Græcia" of Catanzaro, Italy; IRCCS San Raffaele, Rome, Italy
| | | | - Francesco Romeo
- Department of Medicine, University of Rome Tor Vergata, Rome, Italy
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14
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Hydroxyoctadecadienoic Acids Regulate Apoptosis in Human THP-1 Cells in a PPARγ-Dependent Manner. Lipids 2014; 49:1181-92. [DOI: 10.1007/s11745-014-3954-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 09/11/2014] [Indexed: 12/13/2022]
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15
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Adiguzel Z, Arda N, Kacar O, Serhatli M, Gezer Tas S, Baykal AT, Baysal K, Acilan C. Evaluation of apoptotic molecular pathways for smooth muscle cells isolated from thoracic aortic aneurysms in response to oxidized sterols. Mol Biol Rep 2014; 41:7875-84. [DOI: 10.1007/s11033-014-3681-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/19/2014] [Indexed: 12/16/2022]
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16
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Sekiya M, Yamamuro D, Ohshiro T, Honda A, Takahashi M, Kumagai M, Sakai K, Nagashima S, Tomoda H, Igarashi M, Okazaki H, Yagyu H, Osuga JI, Ishibashi S. Absence of Nceh1 augments 25-hydroxycholesterol-induced ER stress and apoptosis in macrophages. J Lipid Res 2014; 55:2082-92. [PMID: 24891333 DOI: 10.1194/jlr.m050864] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
An excess of cholesterol and/or oxysterols induces apoptosis in macrophages, contributing to the development of advanced atherosclerotic lesions. In foam cells, these sterols are stored in esterified forms, which are hydrolyzed by two enzymes: neutral cholesterol ester hydrolase 1 (Nceh1) and hormone-sensitive lipase (Lipe). A deficiency in either enzyme leads to accelerated growth of atherosclerotic lesions in mice. However, it is poorly understood how the esterification and hydrolysis of sterols are linked to apoptosis. Remarkably, Nceh1-deficient thioglycollate-elicited peritoneal macrophages (TGEMs), but not Lipe-deficient TGEMs, were more susceptible to apoptosis induced by oxysterols, particularly 25-hydroxycholesterol (25-HC), and incubation with 25-HC caused massive accumulation of 25-HC ester in the endoplasmic reticulum (ER) due to its defective hydrolysis, thereby activating ER stress signaling such as induction of CCAAT/enhancer-binding protein-homologous protein (CHOP). These changes were nearly reversed by inhibition of ACAT1. In conclusion, deficiency of Nceh1 augments 25-HC-induced ER stress and subsequent apoptosis in TGEMs. In addition to reducing the cholesteryl ester content of foam cells, Nceh1 may protect against the pro-apoptotic effect of oxysterols and modulate the development of atherosclerosis.
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Affiliation(s)
- Motohiro Sekiya
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Daisuke Yamamuro
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Taichi Ohshiro
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Akira Honda
- Joint Research Center, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan
| | - Manabu Takahashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Masayoshi Kumagai
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Kent Sakai
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Shuichi Nagashima
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Hiroshi Tomoda
- Department of Microbial Chemistry, Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
| | - Masaki Igarashi
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Hiroaki Okazaki
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Hiroaki Yagyu
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Jun-ichi Osuga
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Shun Ishibashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
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17
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Lu M, Hu XH, Li Q, Xiong Y, Hu GJ, Xu JJ, Zhao XN, Wei XX, Chang CCY, Liu YK, Nan FJ, Li J, Chang TY, Song BL, Li BL. A specific cholesterol metabolic pathway is established in a subset of HCCs for tumor growth. J Mol Cell Biol 2013; 5:404-15. [PMID: 24163426 DOI: 10.1093/jmcb/mjt039] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The liver plays a central role in cholesterol homeostasis. It exclusively receives and metabolizes oxysterols, which are important metabolites of cholesterol and are more cytotoxic than free cholesterol, from all extrahepatic tissues. Hepatocellular carcinomas (HCCs) impair certain liver functions and cause pathological alterations in many processes including cholesterol metabolism. However, the link between an altered cholesterol metabolism and HCC development is unclear. Human ACAT2 is abundantly expressed in intestine and fetal liver. Our previous studies have shown that ACAT2 is induced in certain HCC tissues. Here, by investigating tissue samples from HCC patients and HCC cell lines, we report that a specific cholesterol metabolic pathway, involving induction of ACAT2 and esterification of excess oxysterols for secretion to avoid cytotoxicity, is established in a subset of HCCs for tumor growth. Inhibiting ACAT2 leads to the intracellular accumulation of unesterified oxysterols and suppresses the growth of both HCC cell lines and their xenograft tumors. Further mechanistic studies reveal that HCC-linked promoter hypomethylation is essential for the induction of ACAT2 gene expression. We postulate that specifically blocking this HCC-established cholesterol metabolic pathway may have potential therapeutic applications for HCC patients.
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Affiliation(s)
- Ming Lu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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18
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Limou S, Zagury JF. Immunogenetics: Genome-Wide Association of Non-Progressive HIV and Viral Load Control: HLA Genes and Beyond. Front Immunol 2013; 4:118. [PMID: 23750159 PMCID: PMC3664380 DOI: 10.3389/fimmu.2013.00118] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/04/2013] [Indexed: 01/11/2023] Open
Abstract
Very early after the identification of the human immunodeficiency virus (HIV), host genetics factors were anticipated to play a role in viral control and disease progression. As early as the mid-1990s, candidate gene studies demonstrated a central role for the chemokine co-receptor/ligand (e.g., CCR5) and human leukocyte antigen (HLA) systems. In the last decade, the advent of genome-wide arrays opened a new era for unbiased genetic exploration of the genome and brought big expectations for the identification of new unexpected genes and pathways involved in HIV/AIDS. More than 15 genome-wide association studies targeting various HIV-linked phenotypes have been published since 2007. Surprisingly, only the two HIV-chemokine co-receptors and HLA loci have exhibited consistent and reproducible statistically significant genetic associations. In this chapter, we will review the findings from the genome-wide studies focusing especially on non-progressive and HIV control phenotypes, and discuss the current perspectives.
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Affiliation(s)
- Sophie Limou
- Basic Science Program, Basic Research Laboratory, Frederick National Laboratory for Cancer ResearchFrederick, MD, USA
| | - Jean-François Zagury
- Chaire de Bioinformatique, Laboratoire Génomique Bioinformatique et Applications (EA 4627), Conservatoire National des Arts et MétiersParis, France
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19
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Blanc M, Hsieh W, Robertson K, Kropp K, Forster T, Shui G, Lacaze P, Watterson S, Griffiths S, Spann N, Meljon A, Talbot S, Krishnan K, Covey D, Wenk M, Craigon M, Ruzsics Z, Haas J, Angulo A, Griffiths W, Glass C, Wang Y, Ghazal P. The transcription factor STAT-1 couples macrophage synthesis of 25-hydroxycholesterol to the interferon antiviral response. Immunity 2013; 38:106-18. [PMID: 23273843 PMCID: PMC3556782 DOI: 10.1016/j.immuni.2012.11.004] [Citation(s) in RCA: 293] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 11/06/2012] [Indexed: 12/18/2022]
Abstract
Recent studies suggest that the sterol metabolic network participates in the interferon (IFN) antiviral response. However, the molecular mechanisms linking IFN with the sterol network and the identity of sterol mediators remain unknown. Here we report a cellular antiviral role for macrophage production of 25-hydroxycholesterol (cholest-5-en-3β,25-diol, 25HC) as a component of the sterol metabolic network linked to the IFN response via Stat1. By utilizing quantitative metabolome profiling of all naturally occurring oxysterols upon infection or IFN-stimulation, we reveal 25HC as the only macrophage-synthesized and -secreted oxysterol. We show that 25HC can act at multiple levels as a potent paracrine inhibitor of viral infection for a broad range of viruses. We also demonstrate, using transcriptional regulatory-network analyses, genetic interventions and chromatin immunoprecipitation experiments that Stat1 directly coupled Ch25h regulation to IFN in macrophages. Our studies describe a physiological role for 25HC as a sterol-lipid effector of an innate immune pathway.
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Affiliation(s)
- Mathieu Blanc
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Wei Yuan Hsieh
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Kevin A. Robertson
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
- SynthSys (Synthetic and Systems Biology), University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JD, UK
| | - Kai A. Kropp
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Thorsten Forster
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Guanghou Shui
- Departments of Biochemistry and Biological Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Paul Lacaze
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Steven Watterson
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
- SynthSys (Synthetic and Systems Biology), University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JD, UK
| | - Samantha J. Griffiths
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Nathanael J. Spann
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Anna Meljon
- Institute of Mass Spectrometry, College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Simon Talbot
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63011, USA
| | - Douglas F. Covey
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63011, USA
| | - Markus R. Wenk
- Departments of Biochemistry and Biological Sciences, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Marie Craigon
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Zsolts Ruzsics
- Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität München, Genzentrum, Feodor Lynen Str. 25, 81377 Munich, Germany
| | - Jürgen Haas
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Ana Angulo
- Facultad de Medicina, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Rosselló 149-153, Barcelona 08036, Spain
| | - William J. Griffiths
- Institute of Mass Spectrometry, College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Christopher K. Glass
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yuqin Wang
- Institute of Mass Spectrometry, College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Peter Ghazal
- Division of Pathway Medicine and Edinburgh Infectious Diseases, University of Edinburgh, Edinburgh EH16 4SB, UK
- SynthSys (Synthetic and Systems Biology), University of Edinburgh, The King’s Buildings, Edinburgh EH9 3JD, UK
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Nakamura-López Y, Sarmiento-Silva RE, Moran-Andrade J, Gómez-García B. Staurosporine-induced apoptosis in P388D1 macrophages involves both extrinsic and intrinsic pathways. Cell Biol Int 2013; 33:1026-31. [DOI: 10.1016/j.cellbi.2009.06.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/09/2009] [Accepted: 06/03/2009] [Indexed: 11/25/2022]
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21
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Liang CP, Han S, Li G, Tabas I, Tall AR. Impaired MEK signaling and SERCA expression promote ER stress and apoptosis in insulin-resistant macrophages and are reversed by exenatide treatment. Diabetes 2012; 61:2609-20. [PMID: 22751695 PMCID: PMC3447920 DOI: 10.2337/db11-1415] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Accumulation of toxic lipids evokes the unfolded protein response (UPR) and apoptotic death of macrophages and vascular cells in atherosclerotic plaques. Primary macrophages from insulin-resistant ob/ob and insulin receptor (Insr)(-/-) mice display increased apoptosis in response to loading with free cholesterol or oxysterol, but underlying mechanisms have not been elucidated. We show increased activation of all three major branches of the UPR in response to free cholesterol or oxysterol loading in insulin-resistant macrophages. Inhibition and rescue experiments revealed that defective MEK/extracellular signal\x{2013}related kinase (ERK)/cAMP-responsive element-binding protein (CREBP) signaling in insulin-resistant macrophages leads to decreased expression of sarcoplasmic endoplasmic reticulum (ER) Ca(2+)-ATPase, depletion of ER calcium stores, PKR-like ER kinase activation, and ER stress-associated apoptosis. Activation of macrophage glucagon-like peptide 1 (GLP-1) receptor via the antidiabetic drug exenatide led to improvements in both ERK and AKT signaling and reversed the increase in UPR and apoptosis of insulin-resistant macrophages in atherosclerotic lesions of ob/ob.Ldlr(-/-) and Insr(-/-).Ldlr(-/-) mice. Increased signaling via GLP-1 receptor or the CREBP activator protein kinase A thus offers a way to rescue insulin-resistant macrophages from excessive ER stress responses and apoptosis in insulin resistance and type 2 diabetes.
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Affiliation(s)
- Chien-Ping Liang
- Department of Medicine, Columbia University, New York, New York, USA.
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22
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Abstract
PURPOSE OF REVIEW To offer a comprehensive review on the roles that oxysterols synthesized or engulfed by macrophages, or oxysterol-binding proteins in these cells, play in the development and progression of atherosclerotic lesions. RECENT FINDINGS Oxysterols abundant within the plaque have the capacity to potentiate macrophage proinflammatory signaling and to induce cell death. These activities may contribute to formation of the complex lesion, expansion of the necrotic core, and to plaque rupture. On the contrary, several endogenous oxysterols generated by cholesterol hydroxylases act as ligands of liver X receptors, stimulate macrophage cholesterol efflux, repress proinflammatory signaling, and promote macrophage survival, counteracting lesion progression. Cytoplasmic oxysterol-binding proteins represent a family of sterol and phosphoinositide sensors that may contribute to the regulatory impact of these bioactive lipids on processes relevant in the context of atherogenesis. SUMMARY The generation and deposition of oxysterols within the developing plaque is envisioned to modulate macrophage lipid metabolism, to affect the delicate balance of proinflammatory and anti-inflammatory processes, and to impact cell fate decisions, thus, determining whether the lesion remains benign or whether it develops into a hazardous, vulnerable plaque.
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Affiliation(s)
- Vesa M Olkkonen
- Minerva Foundation Institute for Medical Research bInstitute of Biomedicine, Anatomy, University of Helsinki, Helsinki, Finland.
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A defect in cell death of macrophages is a conserved feature of nonobese diabetic mouse. Biochem Biophys Res Commun 2012; 421:145-51. [PMID: 22510411 DOI: 10.1016/j.bbrc.2012.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 04/03/2012] [Indexed: 01/04/2023]
Abstract
Impaired apoptosis in immune effector cells such as macrophages has been implicated in the development of autoimmune disease by promoting the breakdown of self-tolerance and the sustained production of cytotoxic molecules. Macrophages from nonobese diabetic (NOD) mouse, an animal model of human autoimmune diabetes, exhibit several defects that are causally linked to the onset and progression of the disease. In this context, we investigated whether NOD macrophages have a defect in a cell death pathway, and if that is the case, the mechanism underlying such dysregulation of cell death. We found that NOD macrophages were resistant to treatment with a broad spectrum of cell death stimuli, triggering both apoptotic and non-apoptotic death. Through analysis of intracellular signaling pathways along with the expression of apoptosis-related proteins, we found that atypical resistance to cell death was associated with an elevated expression of anti-apoptotic Bcl-X(L) but not the NF-κB signaling pathway in NOD macrophages. Further, ABT-737, which can inhibit Bcl-X(L) function, sensitized NOD macrophages to apoptosis induced by diverse apoptotic stimuli, thus restoring sensitivity to cell death. Taken together, our results suggest a macrophage-intrinsic defect in cell death as a potential mechanism that promotes an immune attack towards pancreatic β-cells and the development of autoimmune diabetes in NOD mice.
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24
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Zhou Y, Klein WL. Aβ oligomers-induced toxicity is attenuated in cells cultured with NbActiv4™ medium. Neurotox Res 2012; 22:335-44. [PMID: 22441766 DOI: 10.1007/s12640-012-9318-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 02/28/2012] [Accepted: 03/08/2012] [Indexed: 01/09/2023]
Abstract
Pathogenic Aβ-derived diffusible ligands (ADDLs) bind to post-synaptic targets, induce excessive reactive oxygen species (ROS) and stimulate tau hyperphosphorylation in cultured neurons. Recently, NbActiv4™ medium was reported to increase neuron synapse densities in cultured hippocampal neurons. We aimed to investigate the effect of this novel medium on ADDL-induced toxicity. We found that ADDL-induced ROS was attenuated in cells cultured with NbActiv4™. ADDL binding assay was performed in neurons cultured by different feeding conditions with NbActiv4™. Feeding cells with 30 % medium once a week, ADDL binding sites were abundant at days in vitro (DIV) 18. However, changing 50 % medium once a week decreased ADDL binding about 80 %. NbActiv4™ produced about 40 % more glial fibrillary acidic protein (GFAP) positive astrocytes than the widely used hippocampal culture medium, neurobasal supplemented with B27 (neurobasal/B27). Astrocytes are reported to produce kinds of trophic factors including insulin-like growth factor 1 (IGF-1). Consistently, when cultured with NbActiv4™, neurons were sensitive to inhibitors of insulin/IGF-1 signaling in response to ADDL attack. Overall, this study supports the important role of astrocytes in neuroprotection and indicates that targeting astrocytes dysfunction may lead to new therapeutic strategies for Alzheimer's disease.
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Affiliation(s)
- Yan Zhou
- Northwestern University Interdepartmental Neuroscience Program, 320 East Superior St., Searle 5-474, Chicago, IL 60611, USA.
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25
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Limou S, Delaneau O, van Manen D, An P, Sezgin E, Le Clerc S, Coulonges C, Troyer JL, Veldink JH, van den Berg LH, Spadoni JL, Taing L, Labib T, Montes M, Delfraissy JF, Schachter F, O'Brien SJ, Buchbinder S, van Natta ML, Jabs DA, Froguel P, Schuitemaker H, Winkler CA, Zagury JF. Multicohort genomewide association study reveals a new signal of protection against HIV-1 acquisition. J Infect Dis 2012; 205:1155-62. [PMID: 22362864 DOI: 10.1093/infdis/jis028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND To date, only mutations in CCR5 have been shown to confer resistance to human immunodeficiency virus type 1 (HIV-1) infection, and these explain only a small fraction of the observed variability in HIV susceptibility. METHODS We performed a meta-analysis between 2 independent European genomewide association studies, each comparing HIV-1 seropositive cases with normal population controls known to be HIV uninfected, to identify single-nucleotide polymorphisms (SNPs) associated with the HIV-1 acquisition phenotype. SNPs exhibiting P < 10(-5) in this first stage underwent second-stage analysis in 2 independent US cohorts of European descent. RESULTS After the first stage, a single highly significant association was revealed for the chromosome 8 rs6996198 with HIV-1 acquisition and was replicated in both second-stage cohorts. Across the 4 groups, the rs6996198-T allele was consistently associated with a significant reduced risk of HIV-1 infection, and the global meta-analysis reached genomewide significance: P(combined) = 7.76 × 10(-8). CONCLUSIONS We provide strong evidence of association for a common variant with HIV-1 acquisition in populations of European ancestry. This protective signal against HIV-1 infection is the first identified outside the CCR5 nexus. First clues point to a potential functional role for a nearby candidate gene, CYP7B1, but this locus warrants further investigation.
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Affiliation(s)
- Sophie Limou
- Laboratoire Génomique, Bioinformatique, et Applications, EA4627, Chaire de Bioinformatique, Conservatoire National des Arts et Métiers, Paris, France
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26
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Jordan SD, Krüger M, Willmes DM, Redemann N, Wunderlich FT, Brönneke HS, Merkwirth C, Kashkar H, Olkkonen VM, Böttger T, Braun T, Seibler J, Brüning JC. Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism. Nat Cell Biol 2011; 13:434-46. [PMID: 21441927 DOI: 10.1038/ncb2211] [Citation(s) in RCA: 406] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 01/11/2011] [Indexed: 02/07/2023]
Abstract
The contribution of altered post-transcriptional gene silencing to the development of insulin resistance and type 2 diabetes mellitus so far remains elusive. Here, we demonstrate that expression of microRNA (miR)-143 and 145 is upregulated in the liver of genetic and dietary mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145, impairs insulin-stimulated AKT activation and glucose homeostasis. Conversely, mice deficient for the miR-143-145 cluster are protected from the development of obesity-associated insulin resistance. Quantitative-mass-spectrometry-based analysis of hepatic protein expression in miR-143-overexpressing mice revealed miR-143-dependent downregulation of oxysterol-binding-protein-related protein (ORP) 8. Reduced ORP8 expression in cultured liver cells impairs the ability of insulin to induce AKT activation, revealing an ORP8-dependent mechanism of AKT regulation. Our experiments provide direct evidence that dysregulated post-transcriptional gene silencing contributes to the development of obesity-induced insulin resistance, and characterize the miR-143-ORP8 pathway as a potential target for the treatment of obesity-associated diabetes.
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Affiliation(s)
- Sabine D Jordan
- Department of Mouse Genetics and Metabolism, Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, University Hospital Cologne, Max Planck Institute for Neurological Research, Zülpicher Strasse 47, D-50674 Cologne, Germany
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27
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Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism. Nat Cell Biol 2011. [PMID: 21441927 DOI: 10.1038/ncb2211;] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The contribution of altered post-transcriptional gene silencing to the development of insulin resistance and type 2 diabetes mellitus so far remains elusive. Here, we demonstrate that expression of microRNA (miR)-143 and 145 is upregulated in the liver of genetic and dietary mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145, impairs insulin-stimulated AKT activation and glucose homeostasis. Conversely, mice deficient for the miR-143-145 cluster are protected from the development of obesity-associated insulin resistance. Quantitative-mass-spectrometry-based analysis of hepatic protein expression in miR-143-overexpressing mice revealed miR-143-dependent downregulation of oxysterol-binding-protein-related protein (ORP) 8. Reduced ORP8 expression in cultured liver cells impairs the ability of insulin to induce AKT activation, revealing an ORP8-dependent mechanism of AKT regulation. Our experiments provide direct evidence that dysregulated post-transcriptional gene silencing contributes to the development of obesity-induced insulin resistance, and characterize the miR-143-ORP8 pathway as a potential target for the treatment of obesity-associated diabetes.
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28
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Gieseg SP, Amit Z, Yang YT, Shchepetkina A, Katouah H. Oxidant production, oxLDL uptake, and CD36 levels in human monocyte–derived macrophages are downregulated by the macrophage-generated antioxidant 7,8-dihydroneopterin. Antioxid Redox Signal 2010; 13:1525-34. [PMID: 20408759 DOI: 10.1089/ars.2009.3065] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The severity of atheroma burden in patients strongly correlates to increasing levels of plasma neopterin, the oxidation product of 7,8-dihydroneopterin. Interferon-γ stimulation of macrophages causes the synthesis of 7,8-dihydroneopterin, a potent antioxidant that inhibits oxidative damage to cells, and the cytotoxicity of oxidized low-density lipoprotein (oxLDL) to monocyte-like U937 cells but not THP-1 cells. With human monocyte-derived macrophages (HMDMs), oxLDL triggered a large oxidative stress, causing the rapid loss of cellular glutathione, glyceradehyde-3-phosphate dehydrogenase (GAPDH) inhibition, and eventual loss of viability without caspase-3 activation. Inhibition of oxLDL cytotoxicity to HMDMs occurred at 7,8-dihydroneopterin concentrations >100 μM. The oxLDL-mediated glutathione loss and GAPDH inactivation was inhibited by 7,8-dihydroneopterin. 7,8-Dihydroneopterin rapidly entered the HMDMs, suggesting that much of the protective effect was scavenging of intracellular oxidants generated in response to oxLDL. OxLDL uptake by HMDMs was reduced by 30% by 7,8-dihydroneopterin. Immunoblot analysis suggests that this decrease in oxLDL uptake was due to a significant downregulation in the levels of CD36. These results imply that 7,8-dihydroneopterin protects human macrophages both by scavenging oxidants generated in response to oxLDL and by decreasing CD36-mediated uptake of oxLDL.
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Affiliation(s)
- Steven P Gieseg
- Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
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29
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Moberg C, Catalano RD, Charnock-Jones DS, Olovsson M. VEGF-A and Serum Withdrawal Induced Changes in the Transcript Profile in Human Endometrial Endothelial Cells. Reprod Sci 2010; 17:590-611. [DOI: 10.1177/1933719110364550] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Christian Moberg
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden,
| | - Rob D. Catalano
- Department of Pathology, University of Cambridge and the National Institute for Health Research, Cambridge Biomedical Centre, UK
| | - D. Stephen Charnock-Jones
- Department of Obstetrics and Gynaecology, University of Cambridge and the National Institute for Health Research, Cambridge Biomedical Centre, UK
| | - Matts Olovsson
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
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Liver X Receptor activation downregulates AKT survival signaling in lipid rafts and induces apoptosis of prostate cancer cells. Oncogene 2010; 29:2712-23. [PMID: 20190811 DOI: 10.1038/onc.2010.30] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cholesterol is a structural component of lipid rafts within the plasma membrane. These domains, used as platforms for various signaling molecules, regulate cellular processes including cell survival. Cholesterol contents are tightly correlated with the structure and function of lipid rafts. Liver X receptors (LXRs) have a central role in the regulation of cholesterol homeostasis within the cell. Therefore, we investigated whether these nuclear receptors could modulate lipid raft signaling and consequently alter prostate cancer (PCa) cell survival. Treatment with the synthetic LXR agonist T0901317 downregulated the AKT survival pathway and thus induced apoptosis of LNCaP PCa cells in both xenografted nude mice and cell culture. The decrease in tumor cholesterol content resulted from the upregulation of ABCG1 and the subsequent increase in reverse cholesterol transport. RNA interference experiments showed that these effects were mediated by LXRs. Atomic force microscopy scanning of the inner plasma membrane sheet showed smaller and thinner lipid rafts after LXR stimulation, associated with the downregulation of AKT phosphorylation in these lipid rafts. Replenishment of cell membranes with exogenous cholesterol antagonized these effects, showing that cholesterol is a key modulator in this process. Altogether, pharmacological modulation of LXR activity could thus reduce prostate tumor growth by enhancing apoptosis in a lipid raft-dependent manner.
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31
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Affiliation(s)
- Norihito Shibata
- Department of Cellular and Molecular Medicine, University of California
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32
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Gamble JR, Sun WY, Li X, Hahn CN, Pitson SM, Vadas MA, Bonder CS. Sphingosine kinase-1 associates with integrin {alpha}V{beta}3 to mediate endothelial cell survival. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:2217-25. [PMID: 19815712 DOI: 10.2353/ajpath.2009.090076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sphingosine kinase (SK)-1 promotes endothelial cell (EC) survival through the cell junction molecule CD31 (platelet endothelial cell adhesion molecule-1). The integrin alpha(v)beta(3) is also essential for EC survival; inhibition of alpha(v)beta(3) ligation promotes apoptosis. Herein we demonstrate that under basal conditions, SK-1, alpha(v)beta(3), and CD31 exist as a heterotrimeric complex. Under conditions that affect EC survival such as loss of contact with the extracellular matrix or growth factor activation, more of this heterotrimeric complex forms. Overexpression studies demonstrate a requirement for SK-1 phosphorylation at serine 225 for increased heterotrimeric complex formation, activation of alpha(v)beta(3), and EC survival signals, including Bcl-X and nuclear factor-kappaB pathways. Moreover, beta(3) integrin depletion confirmed the requirement for this heterotrimeric complex in SK-1-mediated EC survival. Thus, with alpha(v)beta(3) integrin being identifiable primarily on angiogenic ECs and SK-1 being highly expressed in tumors, targeting SK-1 may affect multiple survival pathways, and its inhibition may be highly efficacious in controlling pathological EC survival.
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Affiliation(s)
- Jennifer R Gamble
- Centenary Institute for Cancer Medicine and Cell Biology, University of Sydney, Australia
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33
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Effect of oxysterol-induced apoptosis of vascular smooth muscle cells on experimental hypercholesterolemia. J Biomed Biotechnol 2009; 2009:456208. [PMID: 19727411 PMCID: PMC2734998 DOI: 10.1155/2009/456208] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 05/24/2009] [Accepted: 07/07/2009] [Indexed: 01/06/2023] Open
Abstract
Smooth muscle cells (SMCs) undergo changes related to proliferation and apoptosis in the physiological remodeling of vessels and in diseases such as atherosclerosis and restenosis. Recent studies also have demonstrated the vascular cell proliferation and programmed cell death contribute to changes in vascular architecture in normal development and in disease. The present study was designed to investigate the apoptotic pathways induced by 25-hydroxycholesterol in SMCs cultures, using an in vivo/in vitro cell model in which SMCs were isolated and culture from chicken exposed to an atherogenic cholesterol-rich diet (SMC-Ch) and/or an antiatherogenic fish oil-rich diet (SMC-Ch-FO). Cells were exposed in vitro to 25-hydroxycholesterol to study levels of apoptosis and apoptotic proteins Bcl-2, Bcl-X(L) and Bax and the expression of bcl-2 and bcl-x(L), genes. The quantitative real-time reverse transcriptase-polymerase chain reaction and the Immunoblotting western blot analysis showed that 25-hydroxycholesterol produces apoptosis in SMCs, mediated by a high increase in Bax protein and Bax gene expression. These changes were more marked in SMC-Ch than in SMC-Ch-FO, indicating that dietary cholesterol produces changes in SMCs that make them more susceptible to 25-hydroxycholesterol-mediated apoptosis. Our results suggest that the replacement of a cholesterol-rich diet with a fish oil-rich diet produces some reversal of cholesterol-induced changes in the apoptotic pathways induced by 25-hydroxycholesterol in SMCs cultures, making SMCs more resistant to apoptosis.
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34
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Calleros L, Sánchez-Hernández I, Baquero P, Toro MJ, Chiloeches A. Oncogenic Ras, but not (V600E)B-RAF, protects from cholesterol depletion-induced apoptosis through the PI3K/AKT pathway in colorectal cancer cells. Carcinogenesis 2009; 30:1670-7. [PMID: 19700418 DOI: 10.1093/carcin/bgp188] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cholesterol is necessary for proliferation and survival of transformed cells. Here we analyse the effect of cholesterol depletion on apoptosis and the mechanisms underlying this effect in colorectal cancer cells carrying oncogenic Ras or (V600E)B-RAF mutations. We show that chronic cholesterol depletion achieved with lipoprotein-deficient serum (LPDS) and 25-hydroxycholesterol (25-HC) treatment results in a significant increase in apoptosis in HT-29 and Colo-205 cells containing the (V600E)B-RAF mutation, but not in HCT-116 and LoVo cells harbouring the (G13D)Ras mutation, or BE cells, which possess two mutations, (G13D)Ras and (G463V)B-RAF. We also demonstrate that oncogenic Ras protects from apoptosis induced by cholesterol depletion through constitutive activation of the phosphatidylinositol-3 kinase (PI3K)/AKT pathway. The specific activation of the PI3K/AKT pathway by overexpression of the (V12)RasC40 mutant or a constitutively active AKT decreases the LPDS plus 25-HC-induced apoptosis in HT-29 cells, whereas PI3K inhibition or abrogation of AKT expression renders HCT-116 sensitive to cholesterol depletion-induced apoptosis. Moreover, our data show that LPDS plus 25-HC increases the activity of c-Jun N-terminal kinase proteins only in HT-29 cells and that the inhibition of this kinase blocks the apoptosis induced by LPDS plus 25-HC. Finally, we demonstrate that AKT hyperactivation by oncogenic Ras protects from apoptosis, preventing the activation of c-Jun N-terminal kinase by cholesterol depletion. Thus, our data demonstrate that low levels of cholesterol induce apoptosis in colorectal cancer cells without oncogenic Ras mutations. These results reveal a novel molecular characteristic of colon tumours containing Ras or B-RAF mutations and should help in defining new targets for cancer therapy.
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Affiliation(s)
- Laura Calleros
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Alcalá, Madrid, Spain
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35
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Diczfalusy U, Olofsson KE, Carlsson AM, Gong M, Golenbock DT, Rooyackers O, Fläring U, Björkbacka H. Marked upregulation of cholesterol 25-hydroxylase expression by lipopolysaccharide. J Lipid Res 2009; 50:2258-64. [PMID: 19502589 DOI: 10.1194/jlr.m900107-jlr200] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
During screening of genes upregulated by lipopolysaccharide (LPS; endotoxin) treatment of bone marrow-derived mouse macrophages, it was unexpectedly found that cholesterol 25-hydroxylase (Ch25h) was strongly upregulated. Treatment of macrophages with 10 ng/ml of LPS for 2 h resulted in a 35-fold increase in the expression of Ch25h. In contrast, LPS treatment did not increase the expression of Cyp27a1 or Cyp7b1. The increased Ch25h expression was found to be independent of Myeloid differentiation protein 88 signaling but dependent on Toll-like receptor 4 signaling. LPS treatment of macrophages caused a 6- to 7-fold increase in cellular 25-hydroxycholesterol concentration. When macrophages were treated with increasing concentrations of 25-hydroxycholesterol, a dose-dependent release of CCL5 into the culture medium was observed. Intravenous injection of LPS in eight healthy volunteers resulted in an increase in plasma 25-hydroxycholesterol concentration. The possibility is discussed that 25-hydroxycholesterol may have a role in the inflammatory response, in addition to its more established role in the regulation of cholesterol homeostasis.
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Affiliation(s)
- Ulf Diczfalusy
- Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden
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Liu J, Netherland C, Pickle T, Sinensky MS, Thewke DP. Stimulation of Akt poly-ubiquitination and proteasomal degradation in P388D1 cells by 7-ketocholesterol and 25-hydroxycholesterol. Arch Biochem Biophys 2009; 487:54-8. [PMID: 19464253 DOI: 10.1016/j.abb.2009.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 04/30/2009] [Accepted: 05/14/2009] [Indexed: 01/29/2023]
Abstract
Akt plays a role in protecting macrophages from apoptosis induced by some oxysterols. Previously we observed enhanced degradation of Akt in P388D1 moncocyte/macrophages following treatment with 25-hydroxycholesterol (25-OH) or 7-ketocholesterol (7-KC). In the present report we examine the role of the ubiquitin proteasomal pathway in this process. We show that treatment with 25-OH or 7-KC results in the accumulation of poly-ubiquitinated Akt, an effect that is enhanced by co-treatment with the proteasome inhibitor MG-132. Modification of Akt by the addition of a Gly-Ala repeat (GAr), a domain known to block ubiquitin-dependent targeting of proteins to the proteasome, resulted in a chimeric protein that is resistant to turn-over induced by 25-OH or 7-KC and provides protection from apoptosis induced by these oxysterols. These results uncover a new aspect of oxysterol regulation of Akt in macrophages; oxysterol-stimulated poly-ubiquitination of Akt and degradation by the proteasomal pathway.
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Affiliation(s)
- June Liu
- Department of Urology, University of Pittsburg School of Medicine, Pittsburg, PA 15232, USA
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37
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Kippenberger S, Müller J, Schultz M, Dorn A, Bock A, Aygün H, Thaçi D, Hofmann M, Kaufmann R, Bernd A. Oligonucleotides suppress PKB/Akt and act as superinductors of apoptosis in human keratinocytes. Nucleic Acids Res 2009; 37:3850-64. [PMID: 19386618 PMCID: PMC2709556 DOI: 10.1093/nar/gkp252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
DNA oligonucleotides (ODN) applied to an organism are known to modulate the innate and adaptive immune system. Previous studies showed that a CpG-containing ODN (CpG-1-PTO) and interestingly, also a non-CpG-containing ODN (nCpG-5-PTO) suppress inflammatory markers in skin. In the present study it was investigated whether these molecules also influence cell apoptosis. Here we show that CpG-1-PTO, nCpG-5-PTO, and also natural DNA suppress the phosphorylation of PKB/Akt in a cell-type-specific manner. Interestingly, only epithelial cells of the skin (normal human keratinocytes, HaCaT and A-431) show a suppression of PKB/Akt. This suppressive effect depends from ODN lengths, sequence and backbone. Moreover, it was found that TGF alpha-induced levels of PKB/Akt and EGFR were suppressed by the ODN tested. We hypothesize that this suppression might facilitate programmed cell death. By testing this hypothesis we found an increase of apoptosis markers (caspase 3/7, 8, 9, cytosolic cytochrome c, histone associated DNA fragments, apoptotic bodies) when cells were treated with ODN in combination with low doses of staurosporin, a well-known pro-apoptotic stimulus. In summary the present data demonstrate DNA as a modulator of apoptosis which specifically targets skin epithelial cells.
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Affiliation(s)
- Stefan Kippenberger
- Department of Dermatology and Venerology, J.W. Goethe-University, 60590 Frankfurt/Main, Germany.
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Vejux A, Guyot S, Montange T, Riedinger JM, Kahn E, Lizard G. Phospholipidosis and down-regulation of the PI3-K/PDK-1/Akt signalling pathway are vitamin E inhibitable events associated with 7-ketocholesterol-induced apoptosis. J Nutr Biochem 2009; 20:45-61. [DOI: 10.1016/j.jnutbio.2007.12.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 12/06/2007] [Accepted: 12/07/2007] [Indexed: 01/16/2023]
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39
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Differential effects of cholesterol and phytosterols on cell proliferation, apoptosis and expression of a prostate specific gene in prostate cancer cell lines. ACTA ACUST UNITED AC 2009; 32:319-28. [DOI: 10.1016/j.cdp.2008.12.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 11/12/2008] [Accepted: 12/20/2008] [Indexed: 01/06/2023]
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Choi YK, Kim YS, Choi IY, Kim SW, Kim WK. 25-hydroxycholesterol induces mitochondria-dependent apoptosis via activation of glycogen synthase kinase-3beta in PC12 cells. Free Radic Res 2008; 42:544-53. [PMID: 18569012 DOI: 10.1080/10715760802146062] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
25-hydroxycholesterol (25-OH-chol) induces apoptosis in many cell types. The present study investigated the possible involvement of mitochondria-dependent apoptotic signalling molecules in the death of PC12 cells treated with 25-OH-chol. 25-OH-chol increased the production of reactive oxygen species and opened mitochondrial permeability transition pore, resulting in release of cytochrome c and subsequent activation of caspase-9 and -3. 25-OH-chol induced the activation of c-Jun N-terminal kinase (JNK) and glycogen synthase kinase-3beta (GSK-3beta). The JNK inhibitor SP600125 attenuated the activation of caspase-9 and -3 and reduced 25-OH-chol-induced cell death. GSK inhibitors SB415286 and SB216763 significantly down-regulated JNK activity and attenuated the cytotoxicity of 25-hydroxycholesterol. However, SP600125 did not alter the activity of GSK-3beta. The results indicate that 25-OH-chol induces cell death via activation of GSK-3beta and subsequent up-regulation of JNK. Pharmacological intervention of GSK-3beta-JNK-caspase signalling pathway may be useful for the reduction of cytotoxicity of oxysterols.
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Affiliation(s)
- Y K Choi
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
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Effects of apigenin, lycopene and astaxanthin on 7β-hydroxycholesterol-induced apoptosis and Akt phosphorylation in U937 cells. Br J Nutr 2008; 100:287-96. [DOI: 10.1017/s0007114507898643] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Oxysterols arise from the enzymic or non-enzymic oxidation of cholesterol and have been shown to be cytotoxic to certain cell lines. In particular, apoptosis induced by the oxysterol 7β-hydroxycholesterol (7β-OH) has been associated with the generation of oxidative stress, cytochrome c release and caspase activation. Due to the fundamental importance of apoptosis in pathological processes, the identification of substances capable of modulating this form of cell death is now actively researched. The objective of the present study was to investigate if apigenin, lycopene and astaxanthin could inhibit 7β-OH-induced apoptosis in U937 cells. Pretreatment with 0·1 μm-astaxanthin protected against apoptosis, while lycopene did not oppose the adverse effects of 7β-OH. At low concentrations, apigenin did not protect against oxysterol-induced apoptosis; however, at higher concentrations it intensified cell death. Additionally, we investigated the effect of 7β-OH, apigenin and astaxanthin on the activation of the serine threonine kinase Akt (phosphorylated Akt:Akt ratio) to determine whether the effect on cell viability and growth was linked to the Akt signalling pathway. Akt activation was decreased in the oxysterol-treated cells compared with control cells; however, this did not attain significance. Interestingly, activation of Akt was significantly reduced compared with control cells following incubation with apigenin and astaxanthin both in the absence and in the presence of 7β-OH. Our data suggest that apigenin, lycopene and astaxanthin failed to protect against 7β-OH-induced apoptosis, and the decrease in cell viability and the increase in apoptotic nuclei induced by the antioxidants appear to be associated with down regulation of Akt activity.
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Freeman-Anderson NE, Pickle TG, Netherland CD, Bales A, Buckley NE, Thewke DP. Cannabinoid (CB2) receptor deficiency reduces the susceptibility of macrophages to oxidized LDL/oxysterol-induced apoptosis. J Lipid Res 2008; 49:2338-46. [PMID: 18614816 DOI: 10.1194/jlr.m800105-jlr200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Macrophage apoptosis is an important process in the pathophysiology of atherosclerosis. Oxidized low-density lipoproteins (OxLDL) are a major component of lesions and potently induce macrophage apoptosis. Cannabinoid receptor 2 (CB2), the predominant macrophage cannabinoid receptor, modulates several macrophage processes associated with ongoing atherosclerosis; however, the role of CB2 in macrophage apoptosis is unknown. To determine if CB2 influences a macrophage apoptotic pathway relevant to atherosclerosis, we examined the effect of CB2 deficiency on OxLDL-induced macrophage apoptosis. In situ terminal transferase-mediated dUTP nick end labeling (TUNEL) analysis of resident peritoneal macrophages detected significantly fewer apoptotic CB2(-/-) macrophages than CB2(+/+) macrophages after incubation with OxLDL (27.9 +/- 4.7% vs. 61.9 +/- 8.5%, P < 0.001) or 7-ketocholesterol (7KC) (18.9 +/- 10.5% vs. 54.1 +/- 6.9%, P < 0.001), an oxysterol component of OxLDL. Caspase-3 activity; proteolytic conversion of procaspase-3; and cleavage of a caspase-3 substrate, PARP, were also diminished in 7KC-treated CB2(-/-) macrophages. Furthermore, the deactivation of the prosurvival kinase, Akt, in response to 7KC was impaired in CB2(-/-) macrophages. These results suggest that CB2 expression increases the susceptibility of macrophages to OxLDL-induced apoptosis, in part, by modulating the effect of oxysterols on the Akt survival pathway and that CB2 may influence atherosclerosis by modulating lesional macrophage apoptosis.
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Affiliation(s)
- Natalie E Freeman-Anderson
- Department of Biochemistry and Molecular Biology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
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Palozza P, Serini S, Verdecchia S, Ameruso M, Trombino S, Picci N, Monego G, Ranelletti FO. Redox regulation of 7-ketocholesterol-induced apoptosis by beta-carotene in human macrophages. Free Radic Biol Med 2007; 42:1579-90. [PMID: 17448905 DOI: 10.1016/j.freeradbiomed.2007.02.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Revised: 02/16/2007] [Accepted: 02/19/2007] [Indexed: 12/29/2022]
Abstract
The aim of this study was to verify the hypothesis that beta-carotene may prevent 7-ketocholesterol (7-KC)-induced apoptosis in human macrophages. Therefore, THP-1 macrophages were exposed to 7-KC (5-50 microM) alone and in combination with beta-carotene (0.25-1 microM). 7-KC inhibited the growth of macrophages in a dose- and a time-dependent manner by inducing an arrest of cell cycle progression in the G0/G1 phase and apoptosis. Concomitantly, p53, p21, and Bax expressions were increased by 7-KC, whereas the levels of AKT, Bcl-2, and Bcl-xL were decreased. beta-Carotene prevented the growth-inhibitory effects of 7-KC in a dose- and time-dependent manner as well as the effects of 7-KC on the expression of cell cycle- and apoptosis-related proteins. 7-KC also enhanced reactive oxygen species (ROS) production through an increased expression of NAD(P)H oxidase (NOX-4). The effects of 7-KC were counteracted by the addition of the NAD(P)H oxidase inhibitor DPI or by cotransfection of siNOX-4 mRNA. beta-Carotene prevented 7-KC-induced increase in ROS production and in NOX-4 expression, as well as the phosphorylation of p38, JNK, and ERK1/2 induced by 7-KC. These data suggest a possible antiatherogenic role of beta-carotene through the prevention of 7-KC toxicity in human macrophages.
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Affiliation(s)
- Paola Palozza
- Institute of General Pathology, Catholic University School of Medicine, L. Go F. Vito, 1 00168 Rome, Italy.
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Schwartzenberg S, Deutsch V, Maysel-Auslender S, Kissil S, Keren G, George J. Circulating Apoptotic Progenitor Cells. Arterioscler Thromb Vasc Biol 2007; 27:e27-31. [PMID: 17332488 DOI: 10.1161/atvbaha.107.139626] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Progenitor CD34 cells are capable of differentiating into endothelial cells and play a role in neoangiogenesis. Circulating CD34+ cells and endothelial progenitor cells are increased in acute coronary syndrome (ACS) patients possibly because of peripheral mobilization. We tested the hypothesis that circulating apoptotic progenitors are detectable in healthy subjects and altered in ACS patients. METHODS AND RESULTS Peripheral blood mononuclear cells were isolated by Ficoll density gradient from 53 patients with ACS undergoing coronary angiography and 27 healthy subjects. Apoptosis in progenitor CD34+ cells was assessed using the Annexin V-PE/7-AAD detection kit, and fluorescence-activated cell sorter analysis was performed with triple staining for CD34, annexin-V, and 7-AAD. The percentage of apoptotic CD34+ progenitors was determined in the 2 subject groups and correlated with clinical characteristics. The percentage of apoptotic CD34+ progenitor cells was significantly increased in patients with ACS as compared with healthy subjects and was associated with the extent of coronary stenosis by angiography. There was no significant correlation between apoptotic progenitor CD34+ cells and the other parameters that we examined (age, smoking, hypertension, hyperlipidemia, diabetes mellitus, ejection fraction, creatinine levels, or taking any of the various medications, including beta blockers, thiazides, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium blockers, nitrates, or statins). CONCLUSION We established for the first time to our knowledge an assay to detect circulating apoptotic progenitor cells using fluorescein isothiocyanate-anti-CD34 MAb, annexin V-PE, and 7-AAD and found that apoptotic CD34+ cells are increased in ACS patients and in patients with more extensive coronary artery disease. This novel assay may shed new light on the factors governing the hemostasis of progenitor CD34+ cells.
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Arca M, Natoli S, Micheletta F, Riggi S, Di Angelantonio E, Montali A, Antonini TM, Antonini R, Diczfalusy U, Iuliano L. Increased plasma levels of oxysterols, in vivo markers of oxidative stress, in patients with familial combined hyperlipidemia: reduction during atorvastatin and fenofibrate therapy. Free Radic Biol Med 2007; 42:698-705. [PMID: 17291993 DOI: 10.1016/j.freeradbiomed.2006.12.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 12/11/2006] [Accepted: 12/12/2006] [Indexed: 11/23/2022]
Abstract
Familial combined hyperlipidemia (FCHL), the most common inherited disorder of lipid metabolism, is associated with an increased risk of atherosclerosis that is not fully explained by the metabolic disturbances of these patients. Oxidative damage to lipid components accumulating in the plasma of FCHL patients might contribute to explaining this lack of evidence. Cholesterol is one of the preferential targets of oxidation in LDL and this may contribute to setting a proatherogenetic phenotype in FCHL. We investigated plasma oxysterols (7-ketocholesterol and 7beta-hydroxycholesterol) and alpha-tocopherol as in vivo hallmarks of lipid-related oxidative stress. Oxidative stress hallmarks were measured in 45 FCHL patients and 54 sex- and age-matched healthy controls; in FCHL patients, oxidative stress and lipid profile parameters were also assessed in response to lipid-lowering drugs in a 24-week randomized, open-label trial with atorvastatin or fenofibrate. FCHL patients showed markedly increased levels of oxysterols (p < 0.001) and reduced alpha-tocopherol/total lipids (p < 0.001) compared to controls. These differences were independent of the presence of clinical atherosclerosis and persisted after correction for hyperlipidemia. Atorvastatin and fenofibrate significantly improved the lipid profile and caused a comparable decrease in plasma oxysterols, with the normalization of 7-ketocholesterol and a significant reduction of 7beta-hydroxycholesterol (p < 0.001). These drugs also decreased the ratio of alpha-tocopherol/total lipids by more than 30% (p < 0.001). In conclusion, FCHL patients showed increased hallmarks of cholesterol oxidation and decreased levels of alpha-tocopherol/total lipids. Atorvastatin and fenofibrate displayed comparable efficiency in decreasing oxysterols, but they further decreased lipid-corrected alpha-tocopherol levels in plasma. More research work is needed to understand the clinical meaning of these findings, which may help to understand the role of oxidative stress in FCHL and lipid-lowering therapy.
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Affiliation(s)
- Marcello Arca
- Department of Clinical and Applied Medical Therapy, University La Sapienza, 00161 Rome, Italy
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Abstract
Apoptosis has been recognized as a central component in the pathogenesis of atherosclerosis, in addition to the other human pathologies such as cancer and diabetes. The pathophysiology of atherosclerosis is complex, involving both apoptosis and proliferation at different phases of its progression. Oxidative modification of lipids and inflammation differentially regulate the apoptotic and proliferative responses of vascular cells during progression of the atherosclerotic lesion. Bcl-2 proteins act as the major regulators of extrinsic and intrinsic apoptosis signalling pathways and more recently it has become evident that they mediate the apoptotic response of vascular cells in response to oxidation and inflammation either in a provocative or an inhibitory mode of action. Here we address Bcl-2 proteins as major therapeutic targets for the treatment of atherosclerosis and underscore the need for the novel preventive and therapeutic interventions against atherosclerosis, which should be designed in the light of molecular mechanisms regulating apoptosis of vascular cells in atherosclerotic lesions.
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Affiliation(s)
- Ozgur Kutuk
- Biological Sciences and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Orhanli, Tuzla, Istanbul, Turkey
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Travert C, Carreau S, Le Goff D. Induction of apoptosis by 25-hydroxycholesterol in adult rat Leydig cells: Protective effect of 17β-estradiol. Reprod Toxicol 2006; 22:564-70. [PMID: 17023141 DOI: 10.1016/j.reprotox.2006.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 04/24/2006] [Accepted: 05/04/2006] [Indexed: 11/18/2022]
Abstract
Testicular macrophages can convert cholesterol into 25-hydroxycholesterol which strongly stimulates Leydig cell testosterone production. We demonstrated that 25-hydroxycholesterol reduced cholesterol biosynthesis in adult rat Leydig cells. This oxysterol can also be cytotoxic. As hydroxylated cholesterol can induce apoptosis in various cells, we investigated cell death produced by 25-hydroxycholesterol. Apoptosis was characterized by TUNEL assay and by DAPI test. Addition of 25-hydroxycholesterol, during 24h, induced a dose dependent increase of apoptosis. This effect was reduced by a treatment with a caspase-3 inhibitor (Ac-DEVD-CHO). 25-Hydroxycholesterol is known to stimulate testosterone production, but an increase of intracellular or culture medium testosterone level does not modify significantly the percentage of apoptotic cells. In contrast, addition of 17beta-estradiol (2 nM) induced a decrease of apoptotic cells. These data suggested that this oxysterol can be used by rat Leydig cells in culture for sterol metabolism, but also induces apoptosis which could be inhibited by 17beta-estradiol.
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Affiliation(s)
- Carine Travert
- Biochemistry Laboratory EA 2608-USC INRA 2006, IBFA, University of Caen, Esplanade de la Paix, 14302 Caen Cedex, France.
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Massey JB, Pownall HJ. Structures of biologically active oxysterols determine their differential effects on phospholipid membranes. Biochemistry 2006; 45:10747-58. [PMID: 16939227 DOI: 10.1021/bi060540u] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxysterols, derivatives of cholesterol that contain a second oxygen moiety, are intermediates in cholesterol catabolism, regulators of lipid metabolism, and toxic sterols with proatherogenic effects. In model membranes, cholesterol and eight selected oxysterols were compared by fluorescence probe techniques that measure changes in bilayer order and phase behavior and by the formation of detergent-resistant membranes (DRM). The oxysterols were modified on the sterol nucleus or on the isooctyl side chain. The model membranes consisted of dipalmitoyl phosphatidylcholine (DPPC) and mixtures of dioleoyl phosphatidylcholine with DPPC and with sphingomyelin. The different oxysterols induced changes in membrane properties according to the differences in their structures. Whereas the effects of some oxysterols on membrane order, fluorescence probe microenvironment, and DRM formation were similar to those of cholesterol, others had little or no effect. An empirical correlation ranking the oxysterols by their ability to modify membrane biophysical properties when compared to cholesterol led to a significant structure/function relationship between the biophysical measurements and an important cellular phenomenon, apoptosis. 7beta-Hydroxycholesterol, which is the most cytotoxic of the eight selected oxysterols, was one of the least cholesterol-like with respect to modification of membrane properties. The results suggest that an underlying mechanism for oxysterol-induced apoptosis in cells, e.g., monocyte/macrophages, should include their biophysical effects on membranes, such as the regulation of the formation and composition of sterol-rich membrane domains.
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Affiliation(s)
- John B Massey
- Section of Atherosclerosis and Lipoprotein Research, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
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Yan D, Guo L, Wang Y. Requirement of dendritic Akt degradation by the ubiquitin-proteasome system for neuronal polarity. ACTA ACUST UNITED AC 2006; 174:415-24. [PMID: 16864652 PMCID: PMC2064237 DOI: 10.1083/jcb.200511028] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Asymmetric distributions of activities of the protein kinases Akt and glycogen synthase kinase 3β (GSK-3β) are critical for the formation of neuronal polarity. However, the mechanisms underlying polarized regulation of this pathway remain unclear. In this study, we report that the instability of Akt regulated by the ubiquitin–proteasome system (UPS) is required for neuron polarity. Preferential distribution in the axons was observed for Akt but not for its target GSK-3β. A photoactivatable GFP fused to Akt revealed the preferential instability of Akt in dendrites. Akt but not p110 or GSK-3β was ubiquitinated. Suppressing the UPS led to the symmetric distribution of Akt and the formation of multiple axons. These results indicate that local protein degradation mediated by the UPS is important in determining neuronal polarity.
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Affiliation(s)
- Dong Yan
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, Shanghai Institutes of Biological Sciences, China
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