1301
|
Abstract
Inflammasomes are multiprotein signalling platforms that control the inflammatory response and coordinate antimicrobial host defences. They are assembled by pattern-recognition receptors following the detection of pathogenic microorganisms and danger signals in the cytosol of host cells, and they activate inflammatory caspases to produce cytokines and to induce pyroptotic cell death. The clinical importance of inflammasomes reaches beyond infectious disease, as dysregulated inflammasome activity is associated with numerous hereditary and acquired inflammatory disorders. In this Review, we discuss the recent developments in inflammasome research with a focus on the molecular mechanisms that govern inflammasome assembly, signalling and regulation.
Collapse
Affiliation(s)
- Petr Broz
- Focal Area Infection Biology, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Vishva M Dixit
- Genentech Inc., South San Francisco, California 94080, USA
| |
Collapse
|
1302
|
Arbore G, Kemper C. A novel "complement-metabolism-inflammasome axis" as a key regulator of immune cell effector function. Eur J Immunol 2016; 46:1563-73. [PMID: 27184294 PMCID: PMC5025719 DOI: 10.1002/eji.201546131] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/27/2016] [Accepted: 05/13/2016] [Indexed: 12/20/2022]
Abstract
The inflammasomes are intracellular multiprotein complexes that induce and regulate the generation of the key pro‐inflammatory cytokines IL‐1β and IL‐18 in response to infectious microbes and cellular stress. The activation of inflammasomes involves several upstream signals including classic pattern or danger recognition systems such as the TLRs. Recently, however, the activation of complement receptors, such as the anaphylatoxin C3a and C5a receptors and the complement regulator CD46, in conjunction with the sensing of cell metabolic changes, for instance increased amino acid influx and glycolysis (via mTORC1), have emerged as additional critical activators of the inflammasome. This review summarizes recent advances in our knowledge about complement‐mediated inflammasome activation, with a specific focus on a novel “complement – metabolism – NLRP3 inflammasome axis.”
Collapse
Affiliation(s)
- Giuseppina Arbore
- MRC Centre for Transplantation, Division of Transplant Immunology and Mucosal Biology, King's College London, London, UK
| | - Claudia Kemper
- MRC Centre for Transplantation, Division of Transplant Immunology and Mucosal Biology, King's College London, London, UK.,Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD, USA
| |
Collapse
|
1303
|
Bradford BJ, Yuan K, Ylioja C. Managing complexity: Dealing with systemic crosstalk in bovine physiology. J Dairy Sci 2016; 99:4983-4996. [DOI: 10.3168/jds.2015-10271] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/11/2015] [Indexed: 01/15/2023]
|
1304
|
Triantafilou M, Hughes TR, Morgan BP, Triantafilou K. Complementing the inflammasome. Immunology 2016; 147:152-64. [PMID: 26572245 DOI: 10.1111/imm.12556] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 11/03/2015] [Accepted: 11/06/2015] [Indexed: 01/02/2023] Open
Abstract
The innate immune system is an ancient surveillance system able to sense microbial invaders as well as aberrations in normal cell function. No longer viewed as a static and non-specific part of immunity, the innate immune system employs a plethora of specialized pattern recognition sensors to monitor and achieve homeostasis; these include the Toll-like receptors, the retinoic acid-inducible gene-like receptors, the nucleotide-binding oligomerization domain receptors (NLRs), the C-type lectins and the complement system. In order to increase specificity and diversity, innate immunity uses homotypic and heterotypic associations among these different components. Multi-molecular assemblies are formed both on the cell surface and in the cytosol to respond to pathogen and danger signals. Diverse, but tailored, responses to a changing environment are orchestrated depending on the the nature of the challenge and the repertoire of interacting receptors and components available in the sensing cell. It is now emerging that innate immunity operates a system of 'checks and balances' where interaction among the sensors is key in maintaining normal cell function. Complement sits at the heart of this alarm system and it is becoming apparent that it is capable of interacting with all the other pathways to effect a tailored immune response. In this review, we will focus on complement interactions with NLRs, the so-called 'inflammasomes', describing the molecular mechanisms that have been revealed so far and discussing the circumstantial evidence that exists for these interactions in disease states.
Collapse
Affiliation(s)
- Martha Triantafilou
- Institute of Infection and Immunity, School of Medicine, University Hospital of Wales, Cardiff University, Cardiff, UK
| | - Timothy R Hughes
- Institute of Infection and Immunity, School of Medicine, University Hospital of Wales, Cardiff University, Cardiff, UK
| | - Bryan Paul Morgan
- Institute of Infection and Immunity, School of Medicine, University Hospital of Wales, Cardiff University, Cardiff, UK
| | - Kathy Triantafilou
- Institute of Infection and Immunity, School of Medicine, University Hospital of Wales, Cardiff University, Cardiff, UK
| |
Collapse
|
1305
|
Nagao M, Toh R, Irino Y, Mori T, Nakajima H, Hara T, Honjo T, Satomi-Kobayashi S, Shinke T, Tanaka H, Ishida T, Hirata KI. β-Hydroxybutyrate elevation as a compensatory response against oxidative stress in cardiomyocytes. Biochem Biophys Res Commun 2016; 475:322-8. [PMID: 27216458 DOI: 10.1016/j.bbrc.2016.05.097] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 05/19/2016] [Indexed: 12/31/2022]
Abstract
Recent studies have shown that the ketone body β-hydroxybutyrate (βOHB) acts not only as a carrier of energy but also as a signaling molecule that has a role in diverse cellular functions. Circulating levels of ketone bodies have been previously reported to be increased in patients with congestive heart failure (HF). In this study, we investigated regulatory mechanism and pathophysiological role of βOHB in HF. First, we revealed that βOHB level was elevated in failing hearts, but not in blood, using pressure-overloaded mice. We also measured cellular βOHB levels in both cardiomyocytes and non-cardiomyocytes stimulated with or without H2O2 and revealed that increased myocardial βOHB was derived from cardiomyocytes but not non-cardiomyocytes under pathological states. Next, we sought to elucidate the mechanisms of myocardial βOHB elevation and its implication under pathological states. The gene and protein expression levels of CoA transferase (SCOT), a key enzyme involved in ketone body oxidation, was decreased in failing hearts. In cardiomyocytes, H2O2 stimulation caused βOHB accumulation concomitantly with SCOT downregulation, implying that the accumulation of myocardial βOHB occurs because of the decline in its utilization. Finally, we checked the effects of βOHB on cardiomyocytes under oxidative stress. We found that βOHB induced FOXO3a, an oxidative stress resistance gene, and its target enzyme, SOD2 and catalase. Consequently, βOHB attenuated reactive oxygen species production and alleviated apoptosis induced by oxidative stress. It has been reported that hyperadrenergic state in HF boost lipolysis and result in elevation of circulating free fatty acids, which can lead hepatic ketogenesis for energy metabolism alteration. The present findings suggest that the accumulation of βOHB also occurs as a compensatory response against oxidative stress in failing hearts.
Collapse
Affiliation(s)
- Manabu Nagao
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Ryuji Toh
- Division of Evidence-Based Laboratory Medicine, Kobe University Graduate School of Medicine, Japan.
| | - Yasuhiro Irino
- Division of Evidence-Based Laboratory Medicine, Kobe University Graduate School of Medicine, Japan
| | - Takeshige Mori
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Hideto Nakajima
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Tetsuya Hara
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Tomoyuki Honjo
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Seimi Satomi-Kobayashi
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Toshiro Shinke
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Hidekazu Tanaka
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Tatsuro Ishida
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan
| | - Ken-Ichi Hirata
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University, Graduate School of Medicine, Japan; Division of Evidence-Based Laboratory Medicine, Kobe University Graduate School of Medicine, Japan
| |
Collapse
|
1306
|
Sato S, Jung H, Nakagawa T, Pawlosky R, Takeshima T, Lee WR, Sakiyama H, Laxman S, Wynn RM, Tu BP, MacMillan JB, De Brabander JK, Veech RL, Uyeda K. Metabolite Regulation of Nuclear Localization of Carbohydrate-response Element-binding Protein (ChREBP): ROLE OF AMP AS AN ALLOSTERIC INHIBITOR. J Biol Chem 2016; 291:10515-27. [PMID: 26984404 PMCID: PMC4865902 DOI: 10.1074/jbc.m115.708982] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/01/2016] [Indexed: 11/06/2022] Open
Abstract
The carbohydrate-response element-binding protein (ChREBP) is a glucose-responsive transcription factor that plays an essential role in converting excess carbohydrate to fat storage in the liver. In response to glucose levels, ChREBP is regulated by nuclear/cytosol trafficking via interaction with 14-3-3 proteins, CRM-1 (exportin-1 or XPO-1), or importins. Nuclear localization of ChREBP was rapidly inhibited when incubated in branched-chain α-ketoacids, saturated and unsaturated fatty acids, or 5-aminoimidazole-4-carboxamide ribonucleotide. Here, we discovered that protein-free extracts of high fat-fed livers contained, in addition to ketone bodies, a new metabolite, identified as AMP, which specifically activates the interaction between ChREBP and 14-3-3. The crystal structure showed that AMP binds directly to the N terminus of ChREBP-α2 helix. Our results suggest that AMP inhibits the nuclear localization of ChREBP through an allosteric activation of ChREBP/14-3-3 interactions and not by activation of AMPK. AMP and ketone bodies together can therefore inhibit lipogenesis by restricting localization of ChREBP to the cytoplasm during periods of ketosis.
Collapse
Affiliation(s)
- Shogo Sato
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Hunmin Jung
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Tsutomu Nakagawa
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Robert Pawlosky
- the National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-8115, and
| | - Tomomi Takeshima
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Wan-Ru Lee
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Haruhiko Sakiyama
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Sunil Laxman
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - R Max Wynn
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Benjamin P Tu
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - John B MacMillan
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Jef K De Brabander
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Richard L Veech
- the National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892-8115, and
| | - Kosaku Uyeda
- From the Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, the Dallas Veterans Affairs Medical Center, Dallas, Texas 75216
| |
Collapse
|
1307
|
Xiong XY, Liu L, Yang QW. Functions and mechanisms of microglia/macrophages in neuroinflammation and neurogenesis after stroke. Prog Neurobiol 2016; 142:23-44. [PMID: 27166859 DOI: 10.1016/j.pneurobio.2016.05.001] [Citation(s) in RCA: 456] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/20/2016] [Accepted: 05/01/2016] [Indexed: 02/08/2023]
Abstract
Microglia/macrophages are the major immune cells involved in the defence against brain damage. Their morphology and functional changes are correlated with the release of danger signals induced by stroke. These cells are normally responsible for clearing away dead neural cells and restoring neuronal functions. However, when excessively activated by the damage-associated molecular patterns following stroke, they can produce a large number of proinflammatory cytokines that can disrupt neural cells and the blood-brain barrier and influence neurogenesis. These effects indicate the important roles of microglia/macrophages in the pathophysiological processes of stroke. However, the modifiable and adaptable nature of microglia/macrophages may also be beneficial for brain repair and not just result in damage. These distinct roles may be attributed to the different microglia/macrophage phenotypes because the M1 population is mainly destructive, while the M2 population is neuroprotective. Additionally, different gene expression signature changes in microglia/macrophages have been found in diverse inflammatory milieus. These biofunctional features enable dual roles for microglia/macrophages in brain damage and repair. Currently, it is thought that the proper inflammatory milieu may provide a suitable microenvironment for neurogenesis; however, detailed mechanisms underlying the inflammatory responses that initiate or inhibit neurogenesis remain unknown. This review summarizes recent progress concerning the mechanisms involved in brain damage, repair and regeneration related to microglia/macrophage activation and phenotype transition after stroke. We also argue that future translational studies should be targeting multiple key regulating molecules to improve brain repair, which should be accompanied by the concept of a "therapeutic time window" for sequential therapies.
Collapse
Affiliation(s)
- Xiao-Yi Xiong
- Department of Neurology, Xinqiao Hospital & The Second Affiliated Hospital, The Third Military Medical University, Xinqiao zhengjie No.183, Shapingba District Chongqing, 400037, China
| | - Liang Liu
- Department of Neurology, Xinqiao Hospital & The Second Affiliated Hospital, The Third Military Medical University, Xinqiao zhengjie No.183, Shapingba District Chongqing, 400037, China
| | - Qing-Wu Yang
- Department of Neurology, Xinqiao Hospital & The Second Affiliated Hospital, The Third Military Medical University, Xinqiao zhengjie No.183, Shapingba District Chongqing, 400037, China.
| |
Collapse
|
1308
|
Nandivada P, Fell GL, Pan AH, Nose V, Ling PR, Bistrian BR, Puder M. Eucaloric Ketogenic Diet Reduces Hypoglycemia and Inflammation in Mice with Endotoxemia. Lipids 2016; 51:703-14. [PMID: 27117864 DOI: 10.1007/s11745-016-4156-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/09/2016] [Indexed: 11/29/2022]
Abstract
Dietary strategies to alter the immune response to acute inflammation have the potential to improve outcomes in critically ill patients. A eucaloric ketogenic diet (EKD), composed predominantly of fat with very small amounts of carbohydrate, can provide adequate caloric support while minimizing spikes in blood glucose and reducing oxidative stress. The purpose of this study was to evaluate the effects of an EKD on glycemic control and the inflammatory response after acute endotoxemia in mice. Mice received either an EKD or a carbohydrate-based control diet (CD) for 4 weeks. Animals subsequently underwent either a 2-h fast (postprandial) or an overnight fast (postabsorptive), and half of the animals in each diet group were randomized to receive either intraperitoneal lipopolysaccharide (1 mg/kg) or an equivalent volume of saline. Glycemic response, insulin resistance, inflammatory cytokine levels, and the expression of key inflammatory and metabolic genes were measured. After endotoxin challenge, hypoglycemia was more frequent in mice fed a CD than an EKD in the postprandial period. This was due in part to the preservation of hepatic glycogen stores despite endotoxin exposure and prolonged fasting in mice fed an EKD. Furthermore, mice fed the CD had higher levels of IL-6 and TNF-α in the postabsorptive period, with a fivefold higher expression of hepatic NFκB compared to mice fed the EKD in both fasting periods. These results suggest that the unique metabolic state induced by an EKD can alter the response to acute inflammation in mice.
Collapse
Affiliation(s)
- Prathima Nandivada
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Gillian L Fell
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Amy H Pan
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA
| | - Vania Nose
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Pei-Ra Ling
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Bruce R Bistrian
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mark Puder
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave, Boston, MA, 02115, USA.
| |
Collapse
|
1309
|
Ramadi KB, Mohamed YA, Al-Sbiei A, Almarzooqi S, Bashir G, Al Dhanhani A, Sarawathiamma D, Qadri S, Yasin J, Nemmar A, Fernandez-Cabezudo MJ, Haik Y, Al-Ramadi BK. Acute systemic exposure to silver-based nanoparticles induces hepatotoxicity and NLRP3-dependent inflammation. Nanotoxicology 2016; 10:1061-74. [DOI: 10.3109/17435390.2016.1163743] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
| | | | | | - Saeeda Almarzooqi
- Department of Pathology, United Arab Emirates University, Al Ain, United Arab Emirates,
| | - Ghada Bashir
- Department of Medical Microbiology & Immunology, and
| | | | | | - Shahnaz Qadri
- Department of Mechanical Engineering, College of Engineering, United Arab Emirates University, Al Ain, United Arab Emirates,
| | | | - Abderrahim Nemmar
- Department of Physiology, United Arab Emirates University, Al Ain, United Arab Emirates, and
| | - Maria J. Fernandez-Cabezudo
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Yousef Haik
- Department of Mechanical Engineering, College of Engineering, United Arab Emirates University, Al Ain, United Arab Emirates,
| | | |
Collapse
|
1310
|
Rojas-Morales P, Tapia E, Pedraza-Chaverri J. β-Hydroxybutyrate: A signaling metabolite in starvation response? Cell Signal 2016; 28:917-23. [PMID: 27083590 DOI: 10.1016/j.cellsig.2016.04.005] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/09/2016] [Indexed: 02/08/2023]
Abstract
Ketone bodies β-hydroxybutyrate (BHB) and acetoacetate are important metabolic substrates for energy production during prolonged fasting. However, BHB also has signaling functions. Through several metabolic pathways or processes, BHB modulates nutrient utilization and energy expenditure. These findings suggest that BHB is not solely a metabolic intermediate, but also acts as a signal to regulate metabolism and maintain energy homeostasis during nutrient deprivation. We briefly summarize the metabolism and emerging physiological functions of ketone bodies and highlight the potential role for BHB as a signaling molecule in starvation response.
Collapse
Affiliation(s)
- Pedro Rojas-Morales
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Edilia Tapia
- Laboratorio de Fisiopatología Renal, Departamento de Nefrología, Instituto Nacional de Cardiología - Ignacio Chávez, Mexico City, Mexico
| | - José Pedraza-Chaverri
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico.
| |
Collapse
|
1311
|
Regulation of inflammasomes by ubiquitination. Cell Mol Immunol 2016; 13:722-728. [PMID: 27063466 DOI: 10.1038/cmi.2016.15] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/21/2016] [Accepted: 02/21/2016] [Indexed: 02/07/2023] Open
Abstract
Inflammasomes are multi-protein complexes that regulate the innate immune response by facilitating the release of inflammatory cytokines in response to pathogen exposure or cellular damage. Pro-inflammatory inflammasome signaling is vital to host defense and helps initiate the process of tissue repair following an insult to the host, but can be injurious, when excessive or chronic. As such, inflammasome activity is tightly regulated. Here we discuss one critical mechanism of inflammasome regulation, ubiquitination, that functions as a universal modulator of protein stability and trafficking. Recent studies have provided important insights into the regulation of inflammasome activation by protein ubiquitination. We review the molecular regulation of inflammasome function, specifically, as it relates to ubiquitination, and discuss the implications for the development of therapeutics to specifically target aberrant inflammasome signaling.
Collapse
|
1312
|
Affiliation(s)
- Michael W Gleeson
- Department of Gastroenterology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Rolland C Dickson
- Department of Gastroenterology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| |
Collapse
|
1313
|
Gicquel T, Robert S, Victoni T, Lagente V. [The NLRP3 inflammasome: Physiopathology and therapeutic application]. Presse Med 2016; 45:438-46. [PMID: 26880081 DOI: 10.1016/j.lpm.2016.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 12/30/2015] [Accepted: 01/11/2016] [Indexed: 11/19/2022] Open
Abstract
The innate immune system constitutes the first line of host defense against pathogens. "Nonself", such as exogenous particles or pathogens, triggers an inflammatory response. Inflammasomes are molecular platforms activated upon cellular infection or stress that trigger the maturation of proinflammatory cytokines such as IL-1β. Activation of the NLRP3 inflammasome pathway, the most extensively studied, appears to be the corner stone of many inflammatory diseases, including Crohn's disease, rheumatoid arthritis and gout. Cryopyrine-associated periodic syndromes (CAPS) are NLRP3 inflammasome-associated diseases. Canakinumab (Ilaris(®)) is the only drug approved for CAPS treatment in France. Targeted therapy against NLRP3 inflammasome and IL-1β might be the new anti-inflammatory drugs.
Collapse
Affiliation(s)
- Thomas Gicquel
- CHU de Rennes, laboratoire de toxicologie biologique et médicolégale, 35033 Rennes, France; Université Rennes 1, faculté de pharmacie, 35043 Rennes, France; Inserm, UMR991 « foie, métabolismes et cancer », 35043 Rennes, France.
| | - Sacha Robert
- Université Rennes 1, faculté de pharmacie, 35043 Rennes, France; Inserm, UMR991 « foie, métabolismes et cancer », 35043 Rennes, France
| | - Tatiana Victoni
- Université Rennes 1, faculté de pharmacie, 35043 Rennes, France; Inserm, UMR991 « foie, métabolismes et cancer », 35043 Rennes, France
| | - Vincent Lagente
- Université Rennes 1, faculté de pharmacie, 35043 Rennes, France; Inserm, UMR991 « foie, métabolismes et cancer », 35043 Rennes, France
| |
Collapse
|
1314
|
Graff EC, Fang H, Wanders D, Judd RL. Anti-inflammatory effects of the hydroxycarboxylic acid receptor 2. Metabolism 2016; 65:102-13. [PMID: 26773933 DOI: 10.1016/j.metabol.2015.10.001] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/09/2015] [Accepted: 10/01/2015] [Indexed: 02/06/2023]
Abstract
The hydroxycarboxylic acid receptors (HCA1-3) are a family of G-protein-coupled receptors that are critical for sensing endogenous intermediates of metabolism. All three receptors are predominantly expressed on adipocytes and mediate anti-lipolytic effects. In addition to adipocytes, HCA2 is highly expressed on immune cells, including macrophages, monocytes, neutrophils and dermal dendritic cells, among other cell types. The endogenous ligand for HCA2 is beta-hydroxybutyrate (β-OHB), a ketone body produced by the liver through β-oxidation when an individual is in a negative energy balance. Recent studies demonstrate that HCA2 mediates profound anti-inflammatory effects in a variety of tissues, indicating that HCA2 may be an important therapeutic target for treating inflammatory disease processes. This review summarizes the roles of HCA2 on inflammation in a number of tissues and clinical states.
Collapse
Affiliation(s)
- Emily C Graff
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States; Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Han Fang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Desiree Wanders
- Department of Nutrition, Georgia State University, Atlanta, GA, United States
| | - Robert L Judd
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States.
| |
Collapse
|
1315
|
Abstract
Low-grade tissue inflammation induced by obesity can result in insulin resistance, which in turn is a key cause of type 2 diabetes mellitus. Cells of the innate immune system produce cytokines and other factors that impair insulin signalling, which contributes to the connection between obesity and the onset of type 2 diabetes mellitus. Here, we review the innate immune cells involved in secreting inflammatory factors in the obese state. In the adipose tissue, these cells include proinflammatory adipose tissue macrophages and natural killer cells. We also discuss the role of innate immune cells, such as anti-inflammatory adipose tissue macrophages, eosinophils, group 2 innate lymphoid cells and invariant natural killer T cells, in maintaining an anti-inflammatory and insulin-sensitive environment in the lean state. In the liver, both Kupffer cells and recruited hepatic macrophages can contribute to decreased hepatic insulin sensitivity. Proinflammatory macrophages might also adversely affect insulin sensitivity in the skeletal muscle and pancreatic β-cell function. Finally, this Review provides an overview of the mechanisms for regulating proinflammatory immune responses that could lead to future therapeutic opportunities to improve insulin sensitivity.
Collapse
Affiliation(s)
- Denise E Lackey
- Department of Medicine, Division of Endocrinology and Metabolism, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0673, USA
| | - Jerrold M Olefsky
- Department of Medicine, Division of Endocrinology and Metabolism, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0673, USA
| |
Collapse
|
1316
|
Abstract
The bidirectional causality between kidney injury and inflammation remains an area of unexpected discoveries. The last decade unraveled the molecular mechanisms of sterile inflammation, which established danger signaling via pattern recognition receptors as a new concept of kidney injury-related inflammation. In contrast, renal cell necrosis remained considered a passive process executed either by the complement-related membrane attack complex, exotoxins, or cytotoxic T cells. Accumulating data now suggest that renal cell necrosis is a genetically determined and regulated process involving specific outside-in signaling pathways. These findings support a unifying theory in which kidney injury and inflammation are reciprocally enhanced in an autoamplification loop, referred to here as necroinflammation. This integrated concept is of potential clinical importance because it offers numerous innovative molecular targets for limiting kidney injury by blocking cell death, inflammation, or both. Here, the contribution of necroinflammation to AKI is discussed in thrombotic microangiopathies, necrotizing and crescentic GN, acute tubular necrosis, and infective pyelonephritis or sepsis. Potential new avenues are further discussed for abrogating necroinflammation-related kidney injury, and questions and strategies are listed for further exploration in this evolving field.
Collapse
Affiliation(s)
- Shrikant R Mulay
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany; and
| | - Andreas Linkermann
- Clinic for Nephrology and Hypertension, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Hans-Joachim Anders
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany; and
| |
Collapse
|
1317
|
The Therapeutic Potential of the Ketogenic Diet in Treating Progressive Multiple Sclerosis. Mult Scler Int 2015; 2015:681289. [PMID: 26839705 PMCID: PMC4709725 DOI: 10.1155/2015/681289] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/02/2015] [Indexed: 01/04/2023] Open
Abstract
Until recently, multiple sclerosis has been viewed as an entirely inflammatory disease without acknowledgment of the significant neurodegenerative component responsible for disease progression and disability. This perspective is being challenged by observations of a dissociation between inflammation and neurodegeneration where the neurodegenerative component may play a more significant role in disease progression. In this review, we explore the relationship between mitochondrial dysfunction and neurodegeneration in multiple sclerosis. We review evidence that the ketogenic diet can improve mitochondrial function and discuss the potential of the ketogenic diet in treating progressive multiple sclerosis for which no treatment currently exists.
Collapse
|
1318
|
Cao X. Self-regulation and cross-regulation of pattern-recognition receptor signalling in health and disease. Nat Rev Immunol 2015; 16:35-50. [DOI: 10.1038/nri.2015.8] [Citation(s) in RCA: 364] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
1319
|
Yu SX, Du CT, Chen W, Lei QQ, Li N, Qi S, Zhang XJ, Hu GQ, Deng XM, Han WY, Yang YJ. Genipin inhibits NLRP3 and NLRC4 inflammasome activation via autophagy suppression. Sci Rep 2015; 5:17935. [PMID: 26659006 PMCID: PMC4675967 DOI: 10.1038/srep17935] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/09/2015] [Indexed: 02/05/2023] Open
Abstract
Inflammasomes are cytoplasmic, multiprotein complexes that trigger caspase-1 activation and IL-1β maturation in response to diverse stimuli. Although inflammasomes play important roles in host defense against microbial infection, overactive inflammasomes are deleterious and lead to various autoinflammatory diseases. In the current study, we demonstrated that genipin inhibits the induction of IL-1β production and caspase-1 activation by NLRP3 and NLRC4 inflammasomes. Furthermore, genipin specifically prevented NLRP3-mediated, but not NLRC4-mediated, ASC oligomerization. Notably, genipin inhibited autophagy, leading to NLRP3 and NLRC4 inflammasome inhibition. UCP2-ROS signaling may be involved in inflammasome suppression by genipin. In vivo, we showed that genipin inhibited NLRP3-dependent IL-1β production and neutrophil flux in LPS- and alum-induced murine peritonitis. Additionally, genipin provided protection against flagellin-induced lung inflammation by reducing IL-1β production and neutrophil recruitment. Collectively, our results revealed a novel role in inhibition of inflammatory diseases for genipin that has been used as therapeutics for centuries in herb medicine.
Collapse
Affiliation(s)
- Shui-Xing Yu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Chong-Tao Du
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Wei Chen
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Qian-Qian Lei
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Ning Li
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Shuai Qi
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Xiao-Jing Zhang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Gui-Qiu Hu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Xu-Ming Deng
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Wen-Yu Han
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yong-Jun Yang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| |
Collapse
|
1320
|
Finkel T. The metabolic regulation of aging. Nat Med 2015; 21:1416-23. [DOI: 10.1038/nm.3998] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/26/2015] [Indexed: 12/14/2022]
|
1321
|
Picard C, Mathieu AL, Hasan U, Henry T, Jamilloux Y, Walzer T, Belot A. Inherited anomalies of innate immune receptors in pediatric-onset inflammatory diseases. Autoimmun Rev 2015; 14:1147-53. [DOI: 10.1016/j.autrev.2015.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
|
1322
|
Castaldo G, Galdo G, Rotondi Aufiero F, Cereda E. Very low-calorie ketogenic diet may allow restoring response to systemic therapy in relapsing plaque psoriasis. Obes Res Clin Pract 2015; 10:348-52. [PMID: 26559897 DOI: 10.1016/j.orcp.2015.10.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/09/2015] [Accepted: 10/16/2015] [Indexed: 12/12/2022]
Abstract
Psoriasis is a chronic disease associated with overweight/obesity and related cardiometabolic complications. The link between these diseases is likely the inflammatory background associated with adipose tissue, particularly the visceral one. Accordingly, previous studies have demonstrated that in the long-term weight loss may improve the response to systemic therapies. We report a case report of a woman in her 40s suffering from relapsing moderate-to-severe plaque psoriasis and obesity-related metabolic syndrome, in whom adequate response to ongoing treatment with biological therapy (adalimumab) was restored after only 4 weeks of very low-calorie, carbohydrate-free (ketogenic), protein-based diet. Accordingly, through rapid and consistent weight loss, very low calorie ketogenic diet may allow restoring a quick response to systemic therapy in a patient suffering from relapsing psoriasis. This intervention should be considered in overweight/obese patients before the rearrangement of systemic therapy. Nonetheless, studies are required to evaluate whether very low calorie ketogenic diets should be preferred to common low-calorie diets to improve the response to systemic therapy at least in patients with moderate-to-severe psoriasis.
Collapse
Affiliation(s)
- Giuseppe Castaldo
- Clinical Nutrition Unit - A.O.R.N. "San Giuseppe Moscati", Avellino, Italy
| | - Giovanna Galdo
- Dermatology and Dermatosurgery Unit - A.O.R.N. "San Giuseppe Moscati", Avellino, Italy
| | | | - Emanuele Cereda
- Nutrition and Dietetics Service, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
| |
Collapse
|
1323
|
Shao BZ, Xu ZQ, Han BZ, Su DF, Liu C. NLRP3 inflammasome and its inhibitors: a review. Front Pharmacol 2015; 6:262. [PMID: 26594174 PMCID: PMC4633676 DOI: 10.3389/fphar.2015.00262] [Citation(s) in RCA: 585] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 10/22/2015] [Indexed: 01/04/2023] Open
Abstract
Inflammasomes are newly recognized, vital players in innate immunity. The best characterized is the NLRP3 inflammasome, so-called because the NLRP3 protein in the complex belongs to the family of nucleotide-binding and oligomerization domain-like receptors (NLRs) and is also known as “pyrin domain-containing protein 3”. The NLRP3 inflammasome is associated with onset and progression of various diseases, including metabolic disorders, multiple sclerosis, inflammatory bowel disease, cryopyrin-associated periodic fever syndrome, as well as other auto-immune and auto-inflammatory diseases. Several NLRP3 inflammasome inhibitors have been described, some of which show promise in the clinic. The present review will describe the structure and mechanisms of activation of the NLRP3 inflammasome, its association with various auto-immune and auto-inflammatory diseases, and the state of research into NLRP3 inflammasome inhibitors.
Collapse
Affiliation(s)
- Bo-Zong Shao
- Department of Pharmacology, Second Military Medical University Shanghai, China
| | - Zhe-Qi Xu
- Department of Pharmacology, Second Military Medical University Shanghai, China
| | - Bin-Ze Han
- Department of Pharmacology, Second Military Medical University Shanghai, China
| | - Ding-Feng Su
- Department of Pharmacology, Second Military Medical University Shanghai, China
| | - Chong Liu
- Department of Pharmacology, Second Military Medical University Shanghai, China
| |
Collapse
|
1324
|
Traba J, Kwarteng-Siaw M, Okoli TC, Li J, Huffstutler RD, Bray A, Waclawiw MA, Han K, Pelletier M, Sauve AA, Siegel RM, Sack MN. Fasting and refeeding differentially regulate NLRP3 inflammasome activation in human subjects. J Clin Invest 2015; 125:4592-600. [PMID: 26529255 DOI: 10.1172/jci83260] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/24/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Activation of the NLRP3 inflammasome is associated with metabolic dysfunction, and intermittent fasting has been shown to improve clinical presentation of NLRP3 inflammasome-linked diseases. As mitochondrial perturbations, which function as a damage-associated molecular pattern, exacerbate NLRP3 inflammasome activation, we investigated whether fasting blunts inflammasome activation via sirtuin-mediated augmentation of mitochondrial integrity. METHODS We performed a clinical study of 19 healthy volunteers. Each subject underwent a 24-hour fast and then was fed a fixed-calorie meal. Blood was drawn during the fasted and fed states and analyzed for NRLP3 inflammasome activation. We enrolled an additional group of 8 healthy volunteers to assess the effects of the sirtuin activator, nicotinamide riboside, on NLRP3 inflammasome activation. RESULTS In the fasting/refeeding study, individuals showed less NLRP3 inflammasome activation in the fasted state compared with that in refed conditions. In a human macrophage line, depletion of the mitochondrial-enriched sirtuin deacetylase SIRT3 increased NLRP3 inflammasome activation in association with excessive mitochondrial ROS production. Furthermore, genetic and pharmacologic SIRT3 activation blunted NLRP3 activity in parallel with enhanced mitochondrial function in cultured cells and in leukocytes extracted from healthy volunteers and from refed individuals but not in those collected during fasting. CONCLUSIONS Together, our data indicate that nutrient levels regulate the NLRP3 inflammasome, in part through SIRT3-mediated mitochondrial homeostatic control. Moreover, these results suggest that deacetylase-dependent inflammasome attenuation may be amenable to targeting in human disease. TRIAL REGISTRATION ClinicalTrials.gov NCT02122575 and NCT00442195. FUNDING Division of Intramural Research, NHLBI of the NIH.
Collapse
|
1325
|
Interleukin-1 Family Cytokines in Liver Diseases. Mediators Inflamm 2015; 2015:630265. [PMID: 26549942 PMCID: PMC4624893 DOI: 10.1155/2015/630265] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 09/27/2015] [Indexed: 02/06/2023] Open
Abstract
The gene encoding IL-1 was sequenced more than 30 years ago, and many related cytokines, such as IL-18, IL-33, IL-36, IL-37, IL-38, IL-1 receptor antagonist (IL-1Ra), and IL-36Ra, have since been identified. IL-1 is a potent proinflammatory cytokine and is involved in various inflammatory diseases. Other IL-1 family ligands are critical for the development of diverse diseases, including inflammatory and allergic diseases. Only IL-1Ra possesses the leader peptide required for secretion from cells, and many ligands require posttranslational processing for activation. Some require inflammasome-mediated processing for activation and release, whereas others serve as alarmins and are released following cell membrane rupture, for example, by pyroptosis or necroptosis. Thus, each ligand has the proper molecular process to exert its own biological functions. In this review, we will give a brief introduction to the IL-1 family cytokines and discuss their pivotal roles in the development of various liver diseases in association with immune responses. For example, an excess of IL-33 causes liver fibrosis in mice via activation and expansion of group 2 innate lymphoid cells to produce type 2 cytokines, resulting in cell conversion into pro-fibrotic M2 macrophages. Finally, we will discuss the importance of IL-1 family cytokine-mediated molecular and cellular networks in the development of acute and chronic liver diseases.
Collapse
|
1326
|
Abstract
Inflammasomes are high molecular weight complexes that sense and react to injury and infection. Their activation induces caspase-1 activation and release of interleukin-1β, a pro-inflammatory cytokine involved in both acute and chronic inflammatory responses. There is increasing evidence that inflammasomes, particularly the NLRP3 inflammasome, act as guardians against noninfectious material. Inappropriate activation of the NLRP3 inflammasome contributes to the progression of many noncommunicable diseases such as gout, type II diabetes, and Alzheimer's disease. Inhibiting the inflammasome may significantly reduce damaging inflammation and is therefore regarded as a therapeutic target. Currently approved inhibitors of interleukin-1β are rilonacept, canakinumab, and anakinra. However, these proteins do not possess ideal pharmacokinetic properties and are unlikely to easily cross the blood-brain barrier. Because inflammation can contribute to neurological disorders, this review focuses on the development of small-molecule inhibitors of the NLRP3 inflammasome.
Collapse
Affiliation(s)
- Alex G Baldwin
- Manchester Pharmacy School, Faculty of Medical and Human Sciences, The University of Manchester , Stopford Building, Oxford Road, Manchester M13 9PT, U.K
| | - David Brough
- Faculty of Life Sciences, The University of Manchester , AV Hill Building, Oxford Road, Manchester M13 9PT, U.K
| | - Sally Freeman
- Manchester Pharmacy School, Faculty of Medical and Human Sciences, The University of Manchester , Stopford Building, Oxford Road, Manchester M13 9PT, U.K
| |
Collapse
|
1327
|
Camell CD, Nguyen KY, Jurczak MJ, Christian BE, Shulman GI, Shadel GS, Dixit VD. Macrophage-specific de Novo Synthesis of Ceramide Is Dispensable for Inflammasome-driven Inflammation and Insulin Resistance in Obesity. J Biol Chem 2015; 290:29402-13. [PMID: 26438821 DOI: 10.1074/jbc.m115.680199] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 12/31/2022] Open
Abstract
Dietary lipid overload and calorie excess during obesity is a low grade chronic inflammatory state with diminished ability to appropriately metabolize glucose or lipids. Macrophages are critical in maintaining adipose tissue homeostasis, in part by regulating lipid metabolism, energy homeostasis, and tissue remodeling. During high fat diet-induced obesity, macrophages are activated by lipid derived "danger signals" such as ceramides and palmitate and promote the adipose tissue inflammation in an Nlrp3 inflammasome-dependent manner. Given that the metabolic fate of fatty acids in macrophages is not entirely elucidated, we have hypothesized that de novo synthesis of ceramide, through the rate-limiting enzyme serine palmitoyltransferase long chain (Sptlc)-2, is required for saturated fatty acid-driven Nlrp3 inflammasome activation in macrophages. Here we report that mitochondrial targeted overexpression of catalase, which is established to mitigate oxidative stress, controls ceramide-induced Nlrp3 inflammasome activation but does not affect the ATP-mediated caspase-1 cleavage. Surprisingly, myeloid cell-specific deletion of Sptlc2 is not required for palmitate-driven Nlrp3 inflammasome activation. Furthermore, the ablation of Sptlc2 in macrophages did not impact macrophage polarization or obesity-induced adipose tissue leukocytosis. Consistent with these data, investigation of insulin resistance using hyperinsulinemic-euglycemic clamps revealed no significant differences in obese mice lacking ceramide de novo synthesis machinery in macrophages. These data suggest that alternate metabolic pathways control fatty acid-derived ceramide synthesis in macrophage and the Nlrp3 inflammasome activation in obesity.
Collapse
Affiliation(s)
- Christina D Camell
- From the Section of Comparative Medicine and Department of Immunobiology
| | - Kim Y Nguyen
- From the Section of Comparative Medicine and Department of Immunobiology
| | | | | | | | - Gerald S Shadel
- Departments of Internal Medicine, Genetics, Yale School of Medicine, New Haven, Connectitcut 06520
| | - Vishwa Deep Dixit
- From the Section of Comparative Medicine and Department of Immunobiology,
| |
Collapse
|
1328
|
Mitoprotective dietary approaches for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Caloric restriction, fasting, and ketogenic diets. Med Hypotheses 2015; 85:690-3. [PMID: 26315446 DOI: 10.1016/j.mehy.2015.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 07/22/2015] [Accepted: 08/16/2015] [Indexed: 12/27/2022]
Abstract
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is an idiopathic illness characterized by debilitating fatigue and neuro-immune abnormalities. A growing body of evidence proposes mitochondrial dysfunction as a central perpetrator of the illness due to activation of immune-inflammatory pathways that burden the mitochondria. Under a model of mitochondrial dysfunction, this paper explores dietary strategies that are mitoprotective. Studied for decades, the cellular mechanisms of ketogenic diets, fasting, and caloric restriction now reveal mitochondria-specific mechanisms which could play a role in symptom reduction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Future research should examine the physiological effects of these dietary strategies in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
Collapse
|
1329
|
GVHD-associated, inflammasome-mediated loss of function in adoptively transferred myeloid-derived suppressor cells. Blood 2015; 126:1621-8. [PMID: 26265697 DOI: 10.1182/blood-2015-03-634691] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 07/24/2015] [Indexed: 02/08/2023] Open
Abstract
Myeloid-derived suppressor cells (MDSCs) are a naturally occurring immune regulatory population associated with inhibition of ongoing inflammatory responses. In vitro generation of MDSCs from bone marrow has been shown to enhance survival in an acute model of lethal graft-versus-host disease (GVHD). However, donor MDSC infusion only partially ameliorates GVHD lethality. In order to improve the potential therapeutic benefit and ultimately survival outcomes, we set out to investigate the fate of MDSCs after transfer in the setting of acute GVHD (aGVHD). MDSCs transferred to lethally irradiated recipients of allogeneic donor hematopoietic grafts are exposed to an intense inflammatory environment associated with aGVHD, which we now show directly undermines their suppressive capacity. Under a conditioning regimen and GVHD inflammatory settings, MDSCs rapidly lose suppressor function and their potential to inhibit GVHD lethality, which is associated with their induced conversion toward a mature inflammasome-activated state. We find even brief in vitro exposure to inflammasome-activating mediators negates the suppressive potential of cultured murine and human-derived MDSCs. Consistent with a role for the inflammasome, donor MDSCs deficient in the adaptor ASC (apoptosis-associated speck-like protein containing a CARD), which assembles inflammasome complexes, conferred improved survival of mice developing GVHD compared with wild-type donor MDSCs. These data suggest the use of MDSCs as a therapeutic approach for preventing GVHD and other systemic inflammatory conditions will be more effective when combined with approaches limiting in vivo MDSC inflammasome activation, empowering MDSCs to maintain their suppressive potential.
Collapse
|
1330
|
Haslberger A, Terkeltaub R. Editorial: Can GPR43 Sensing of Short-Chain Fatty Acids Unchain Inflammasome-Driven Arthritis? Arthritis Rheumatol 2015; 67:1419-23. [PMID: 25914362 DOI: 10.1002/art.39102] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/03/2015] [Indexed: 11/08/2022]
Affiliation(s)
| | - Robert Terkeltaub
- VA San Diego Healthcare System, San Diego, California, and University of California at San Diego, La Jolla, California
| |
Collapse
|
1331
|
Abstract
The high-fat ketogenic diet (KD) is a remarkably effective treatment for medically intractable epilepsy and has been part of the clinical armamentarium for nearly a century. However, the mechanisms underlying the KD's actions have remained elusive. Over the past decade, there has been phenomenal international growth of clinical centers offering metabolism-based therapies for epilepsy, and rapidly expanding research into the cellular and biochemical effects induced by the KD. At present, there are many hypotheses regarding KD action, and while each is uniquely compelling, it is becoming more apparent that the KD likely works through multiple mechanisms that target fundamental biochemical pathways linked to cellular substrates (e.g., ion channels) and mediators responsible for neuronal hyperexcitability. This is not altogether surprising given the complexity of the epileptic brain, and the many different pathophysiologic mechanisms that underlie seizure genesis and epileptogenicity. The scientific literature involving the KD strongly supports the notion that epilepsy may indeed in part represent a "metabolic disease", and that this concept could serve as a novel framework for the development of more effective anti-seizure drugs.
Collapse
|
1332
|
Montgomery RR, Shaw AC. Paradoxical changes in innate immunity in aging: recent progress and new directions. J Leukoc Biol 2015; 98:937-43. [PMID: 26188078 DOI: 10.1189/jlb.5mr0315-104r] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/23/2015] [Indexed: 12/29/2022] Open
Abstract
Immunosenescence, describing alterations, including decline of immune responses with age, is comprised of inappropriate elevations, decreases, and dysregulated immune responses, leading to more severe consequences of bacterial and viral infections and reduced responses to vaccination. In adaptive immunity, these changes include increased proportions of antigen-experienced B and T cells at the cost of naïve cell populations. Innate immune changes in aging are complex in spanning multiple cell types, activation states, and tissue context. Innate immune responses are dampened in aging, yet there is also a paradoxical increase in certain signaling pathways and cytokine levels. Here, we review recent progress and highlight novel directions for expected advances that can lead the aging field to a new era of discovery that will embrace the complexity of aging in human populations.
Collapse
Affiliation(s)
- Ruth R Montgomery
- Sections of *Rheumatology and Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Albert C Shaw
- Sections of *Rheumatology and Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
1333
|
Guo H, Callaway JB, Ting JPY. Inflammasomes: mechanism of action, role in disease, and therapeutics. Nat Med 2015; 21:677-87. [PMID: 26121197 DOI: 10.1038/nm.3893] [Citation(s) in RCA: 2283] [Impact Index Per Article: 253.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/28/2015] [Indexed: 02/06/2023]
Abstract
The inflammasomes are innate immune system receptors and sensors that regulate the activation of caspase-1 and induce inflammation in response to infectious microbes and molecules derived from host proteins. They have been implicated in a host of inflammatory disorders. Recent developments have greatly enhanced our understanding of the molecular mechanisms by which different inflammasomes are activated. Additionally, increasing evidence in mouse models, supported by human data, strongly implicates an involvement of the inflammasome in the initiation or progression of diseases with a high impact on public health, such as metabolic disorders and neurodegenerative diseases. Finally, recent developments pointing toward promising therapeutics that target inflammasome activity in inflammatory diseases have been reported. This review will focus on these three areas of inflammasome research.
Collapse
Affiliation(s)
- Haitao Guo
- The Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Justin B Callaway
- The Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jenny P-Y Ting
- 1] The Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. [2] Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
1334
|
Regulating against the dysregulation: new treatment options in autoinflammation. Semin Immunopathol 2015; 37:429-37. [PMID: 26059720 DOI: 10.1007/s00281-015-0501-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 05/14/2015] [Indexed: 12/29/2022]
Abstract
In autoinflammatory disorders, dysregulation of the innate immune response leads to an excessive cytokine release. The disease course is often characterized by high morbidity and mortality, treatment is mostly difficult and therapeutic options are limited. In most cases, life-long control of ongoing inflammation is necessary in order to improve clinical symptoms and prevent development of damage. Steroids are helpful in many conditions, but the development of serious side effects often limits their long-term use. Other immunosuppressive, steroid-sparing medications are less effective than in the treatment of autoimmune diseases or do not show any effect. So far, anti-IL1α and/or β-blocking agents as well as an IL-6 receptor-blocking monoclonal antibody and, to a lesser extent, TNF-α blocking agents were applied in autoinflammatory disorders and significantly improved the outcome. Although these progresses were made in the last years, there are still numerous challenges in order to improve drug therapy in autoinflammation. This review summarizes the current state of new drug development and discusses advantages and disadvantages of possible targets.
Collapse
|
1335
|
Deleidi M, Jäggle M, Rubino G. Immune aging, dysmetabolism, and inflammation in neurological diseases. Front Neurosci 2015; 9:172. [PMID: 26089771 PMCID: PMC4453474 DOI: 10.3389/fnins.2015.00172] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/28/2015] [Indexed: 12/17/2022] Open
Abstract
As we age, the immune system undergoes a process of senescence accompanied by the increased production of proinflammatory cytokines, a chronic subclinical condition named as “inflammaging”. Emerging evidence from human and experimental models suggest that immune senescence also affects the central nervous system and promotes neuronal dysfunction, especially within susceptible neuronal populations. In this review we discuss the potential role of immune aging, inflammation and metabolic derangement in neurological diseases. The discovery of novel therapeutic strategies targeting age-linked inflammation may promote healthy brain aging and the treatment of neurodegenerative as well as neuropsychiatric disorders.
Collapse
Affiliation(s)
- Michela Deleidi
- Department of Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Hertie Institute for Clinical Brain Research, University of Tübingen Tübingen, Germany
| | - Madeline Jäggle
- Department of Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE), Hertie Institute for Clinical Brain Research, University of Tübingen Tübingen, Germany
| | - Graziella Rubino
- Department of Internal Medicine II, Center for Medical Research, University of Tübingen Tübingen, Germany
| |
Collapse
|
1336
|
|
1337
|
Agyemang AF, Harrison SR, Siegel RM, McDermott MF. Protein misfolding and dysregulated protein homeostasis in autoinflammatory diseases and beyond. Semin Immunopathol 2015; 37:335-47. [DOI: 10.1007/s00281-015-0496-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 05/05/2015] [Indexed: 02/03/2023]
|
1338
|
Abstract
INTRODUCTION After the introduction of highly active antiretroviral treatment, the course of HIV infection turned into a chronic disease and most of HIV-positive patients will soon be over 50 years old. MATERIAL AND METHODS This paper reviews the multiple aspects that physicians have to face while taking care of HIV-positive ageing patients including the definitions of frailty and the prevalence and risk factors of concomitant diseases. From a therapeutic point of view pharmacokinetic changes and antiretroviral-specific toxicities associated with ageing are discussed; finally therapeutic approaches to frailty are reviewed both in HIV-positive and negative patients. CONCLUSION AND DISCUSSION We conclude by suggesting that the combined use of drugs with the least toxicity potential and the promotion of healthy behaviours (including appropriate nutrition and exercise) might be the best practice for ageing HIV-positive subjects.
Collapse
|
1339
|
Groß CJ, Groß O. The Nlrp3 inflammasome admits defeat. Trends Immunol 2015; 36:323-4. [PMID: 25991463 DOI: 10.1016/j.it.2015.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 05/05/2015] [Indexed: 02/02/2023]
Abstract
The Nlrp3 inflammasome triggers interleukin-1 secretion by myeloid cells in response to endogenous and exogenous danger signals. Two recent studies identified the sulfonylurea MCC950 and the ketone metabolite β-hydroxybutyrate as specific inhibitors of the Nlrp3 inflammasome, with promising therapeutic potential for the treatment of auto-inflammatory diseases.
Collapse
Affiliation(s)
- Christina J Groß
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Olaf Groß
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany.
| |
Collapse
|
1340
|
Kim DY, Simeone KA, Simeone TA, Pandya JD, Wilke JC, Ahn Y, Geddes JW, Sullivan PG, Rho JM. Ketone bodies mediate antiseizure effects through mitochondrial permeability transition. Ann Neurol 2015; 78:77-87. [PMID: 25899847 DOI: 10.1002/ana.24424] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 04/03/2015] [Accepted: 04/03/2015] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Ketone bodies (KB) are products of fatty acid oxidation and serve as essential fuels during fasting or treatment with the high-fat antiseizure ketogenic diet (KD). Despite growing evidence that KB exert broad neuroprotective effects, their role in seizure control has not been firmly demonstrated. The major goal of this study was to demonstrate the direct antiseizure effects of KB and to identify an underlying target mechanism. METHODS We studied the effects of both the KD and KB in spontaneously epileptic Kcna1-null mice using a combination of behavioral, planar multielectrode, and standard cellular electrophysiological techniques. Thresholds for mitochondrial permeability transition (mPT) were determined in acutely isolated brain mitochondria. RESULTS KB alone were sufficient to: (1) exert antiseizure effects in Kcna1-null mice, (2) restore intrinsic impairment of hippocampal long-term potentiation and spatial learning-memory defects in Kcna1-null mutants, and (3) raise the threshold for calcium-induced mPT in acutely prepared mitochondria from hippocampi of Kcna1-null animals. Targeted deletion of the cyclophilin D subunit of the mPT complex abrogated the effects of KB on mPT, and in vivo pharmacological inhibition and activation of mPT were found to mirror and reverse, respectively, the antiseizure effects of the KD in Kcna1-null mice. INTERPRETATION The present data reveal the first direct link between mPT and seizure control, and provide a potential mechanistic explanation for the KD. Given that mPT is increasingly being implicated in diverse neurological disorders, our results suggest that metabolism-based treatments and/or metabolic substrates might represent a worthy paradigm for therapeutic development.
Collapse
Affiliation(s)
- Do Young Kim
- Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE
| | - Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE
| | - Jignesh D Pandya
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY
| | - Julianne C Wilke
- Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ
| | - Younghee Ahn
- Departments of Pediatrics and Clinical Neurosciences, Alberta Children's Hospital Research Institute for Child and Maternal Health, University of Calgary Faculty of Medicine, Calgary, Alberta, Canada
| | - James W Geddes
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY
| | - Patrick G Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY
| | - Jong M Rho
- Departments of Pediatrics and Clinical Neurosciences, Alberta Children's Hospital Research Institute for Child and Maternal Health, University of Calgary Faculty of Medicine, Calgary, Alberta, Canada
| |
Collapse
|
1341
|
Abstract
Aging is the greatest risk factor for the development of chronic diseases such as arthritis, type 2 diabetes, cardiovascular disease, kidney disease, Alzheimer's disease, macular degeneration, frailty, and certain forms of cancers. It is widely regarded that chronic inflammation may be a common link in all these age-related diseases. This raises the question, can one alter the course of aging and potentially slow the development of all chronic diseases by manipulating the mechanisms that cause age-related inflammation? Emerging evidence suggests that pro-inflammatory cytokines interleukin-1 (IL-1) and IL-18 show an age-dependent regulation implicating inflammasome-mediated caspase-1 activation in the aging process. The Nod-like receptor (NLR) family of innate immune cell sensors, such as the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome controls the caspase-1 activation in myeloid-lineage cells in several organs during aging. The NLRP3 inflammasome is especially relevant to aging as it can get activated in response to structurally diverse damage-associated molecular patterns (DAMPs) such as extracellular ATP, excess glucose, ceramides, amyloids, urate, and cholesterol crystals, all of which increase with age. Interestingly, reduction in NLRP3-mediated inflammation prevents age-related insulin resistance, bone loss, cognitive decline, and frailty. NLRP3 is a major driver of age-related inflammation and therefore dietary or pharmacological approaches to lower aberrant inflammasome activation holds promise in reducing multiple chronic diseases of age and may enhance healthspan.
Collapse
Affiliation(s)
- Emily L. Goldberg
- Section of Comparative Medicine, Yale School of Medicine, New Haven, CT, USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Vishwa Deep Dixit
- Section of Comparative Medicine, Yale School of Medicine, New Haven, CT, USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| |
Collapse
|
1342
|
Abstract
NLRP3-inflammasome activates caspase-1 and processes pro-IL-1β and pro-IL-18 into the active cytokines. Two recent studies describe specific inhibitors of NLRP3 inflammasome that inhibit IL-1β release and inflammation. The specificity and potency of these compounds gives hope that a targeted approach to inhibit NLRP3-driven inflammation may be just around the corner.
Collapse
Affiliation(s)
- Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Leo A B Joosten
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.
| |
Collapse
|
1343
|
|
1344
|
|