51
|
The antidiabetic agent glibenclamide protects airway hyperresponsiveness and inflammation in mice. Inflammation 2015; 38:835-45. [PMID: 25113133 DOI: 10.1007/s10753-014-9993-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Glibenclamide has a newly discovered role in inflammation regulation besides its antidiabetic effect. As an inhibitor of ATP-sensitive potassium (KATP) channel, glibenclamide antagonizes the relaxation of the tracheal smooth muscle. This indicates that glibenclamide might attenuate airway inflammation while aggravate airway hyperresponsiveness (AHR) in asthmatics. Clinically, many diabetics with asthma are prescribed with glibenclamide to control blood glucose. However, whether glibenclamide could exert any effects on asthmatic inflammation remains unknown. Using an ovalbumin (OVA)-induced mouse model of asthma, we evaluated the effects of glibenclamide on the AHR and inflammation. Interestingly, glibenclamide reduced all the cardinal features of asthma in OVA-challenged mice, including AHR, airway inflammation, and T-helper type 2 (Th2) cytokines. Glibenclamide also downregulated OVA-induced expressions of vascular cell adhesion molecule 1 (VCAM-1) and phosphorylated signal transducer and activator of transcription 6 (p-STAT6) in the lung. In addition, increased sulfonylurea receptor 1 (SUR1) expression in the lung was observed after the OVA challenge. These findings suggest that the classic sulfonylurea glibenclamide plays an important protective role in the development of asthma, which not only provides the evidence for the safety of prescribed glibenclamide in diabetics combined with asthma but also indicates a possible new therapeutic for asthma via targeting glibenclamide-related pathways.
Collapse
|
52
|
Liu Z, Zhao H, Liu W, Li T, Wang Y, Zhao M. NLRP3 inflammasome activation is essential for paraquat-induced acute lung injury. Inflammation 2015; 38:433-44. [PMID: 25338942 PMCID: PMC7101550 DOI: 10.1007/s10753-014-0048-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The innate immune response is important in paraquat-induced acute lung injury, but the exact pathways involved are not elucidated. The objectives of this study were to determine the specific role of the NLRP3 inflammasome in the process. Acute lung injury was induced by administering paraquat (PQ) intraperitoneally. NLRP3 inflammasome including NLRP3, ASC, and caspase-1 mRNA and protein expression in lung tissue and IL-1β and IL-18 levels in BALF were detected at 4, 8, 24, and 72 h after PQ administration in rats. Moreover, rats were pretreated with 10, 30, and 50 mg/kg NLRP3 inflammasome blocker glybenclamide, respectively, 1 h before PQ exposure. At 72 h after PQ administration, lung histopathology changes, NLRP3, ASC, and caspase-1 protein expression, as well as secretion of cytokines including IL-1β and IL-18 in BALF were investigated. The NLRP3 inflammasome including NLRP3, ASC, caspase-1 expression, and cytokines IL-1β and IL-18 levels in PQ poisoning rats were significantly higher than that in the control group. NLRP3 inflammasome blocker glybenclamide pretreatment attenuated lung edema, inhibited the NLRP3, ASC, and caspase-1 activation, and reduced IL-1β and IL-18 levels in BALF. In the in vitro experiments, IL-1β and IL-18 secreted from RAW264.7 mouse macrophages treated with paraquat were attenuated by glybenclamide. In conclusion, paraquat can induce IL-1β/IL-18 secretion via NLRP3-ASC-caspase-1 pathway, and the NLRP3 inflammasome is essential for paraquat-induced acute lung injury.
Collapse
Affiliation(s)
- Zhenning Liu
- Department of Emergency Medicine, Shengjing Hospital of China Medical University, No. 36, Sanhao Street, Heping District, Shenyang, 110004, Liaoning Province, China
| | | | | | | | | | | |
Collapse
|
53
|
Jenjaroen K, Chumseng S, Sumonwiriya M, Ariyaprasert P, Chantratita N, Sunyakumthorn P, Hongsuwan M, Wuthiekanun V, Fletcher HA, Teparrukkul P, Limmathurotsakul D, Day NPJ, Dunachie SJ. T-Cell Responses Are Associated with Survival in Acute Melioidosis Patients. PLoS Negl Trop Dis 2015; 9:e0004152. [PMID: 26495852 PMCID: PMC4619742 DOI: 10.1371/journal.pntd.0004152] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/18/2015] [Indexed: 12/19/2022] Open
Abstract
Background Melioidosis is an increasingly recognised cause of sepsis and death across South East Asia and Northern Australia, caused by the bacterium Burkholderia pseudomallei. Risk factors include diabetes, alcoholism and renal disease, and a vaccine targeting at-risk populations is urgently required. A better understanding of the protective immune response in naturally infected patients is essential for vaccine design. Methods We conducted a longitudinal clinical and immunological study of 200 patients with melioidosis on admission, 12 weeks (n = 113) and 52 weeks (n = 65) later. Responses to whole killed B. pseudomallei were measured in peripheral blood mononuclear cells (PBMC) by interferon-gamma (IFN-γ) ELIspot assay and flow cytometry and compared to those of control subjects in the region with diabetes (n = 45) and without diabetes (n = 43). Results We demonstrated strong CD4+ and CD8+ responses to B. pseudomallei during acute disease, 12 weeks and 52 weeks later. 28-day mortality was 26% for melioidosis patients, and B. pseudomallei-specific cellular responses in fatal cases (mean 98 IFN-γ cells per million PBMC) were significantly lower than those in the survivors (mean 142 IFN-γ cells per million PBMC) in a multivariable logistic regression model (P = 0.01). A J-shaped curve association between circulating neutrophil count and mortality was seen with an optimal count of 4000 to 8000 neutrophils/μl. Melioidosis patients with known diabetes had poor diabetic control (median glycated haemoglobin HbA1c 10.2%, interquartile range 9.2–13.1) and showed a stunted B. pseudomallei-specific cellular response during acute illness compared to those without diabetes. Conclusions The results demonstrate the role of both CD4+ and CD8+ T-cells in protection against melioidosis, and an interaction between diabetes and cellular responses. This supports development of vaccine strategies that induce strong T-cell responses for the control of intracellular pathogens such as B. pseudomallei. Melioidosis is a key cause of death in South East Asia and Northern Australia. It is caused by the soil-dwelling bacteria Burkholderia pseudomallei, and presents as a range of clinical illnesses including pneumonia and bloodstream infections. About two-thirds of patients with melioidosis in Thailand have diabetes, but the immune responses associated with death and diabetes are unknown. This study examined the relationship between immune responses to the bacteria and death by studying the bacteria-specific lymphocyte responses in 200 patients admitted to hospital with acute melioidosis and following the patients for up to one year where possible. 26% of patients died within 28 days despite receiving antibiotics and supportive care. We showed people with melioidosis make bacteria-specific lymphocyte responses, with lower levels seen in fatal cases compared to survivors. People with diabetes make lower responses than people without diabetes, and higher levels of circulating neutrophils on admission to hospital were associated with lower lymphocyte responses both during illness and three months later in survivors. This highlighting of lymphocyte responses to melioidosis is important for the design of vaccines to target at risk groups.
Collapse
Affiliation(s)
- Kemajittra Jenjaroen
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Suchintana Chumseng
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | | | | | - Narisara Chantratita
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Maliwan Hongsuwan
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Vanaporn Wuthiekanun
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Helen A. Fletcher
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Direk Limmathurotsakul
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Susanna J. Dunachie
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| |
Collapse
|
54
|
Shih CJ, Wu YL, Chao PW, Kuo SC, Yang CY, Li SY, Ou SM, Chen YT. Association between Use of Oral Anti-Diabetic Drugs and the Risk of Sepsis: A Nested Case-Control Study. Sci Rep 2015; 5:15260. [PMID: 26463557 PMCID: PMC4604480 DOI: 10.1038/srep15260] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/21/2015] [Indexed: 12/28/2022] Open
Abstract
Although oral antidiabetic drugs (OADs) have been associated with immunomodulation in preclinical studies, little is still known about the association between the use of OADs and the risk of sepsis. Using a cohort of patients, extracted from Taiwan's National Health Insurance Research Database, with type 2 diabetes who were newly diagnosed between 2010 and 2012 and treated with OADs, we conducted a nested case-control study involving 43,015 cases (patients who were first hospitalized for sepsis) and 43,015 matched controls. Compared with non-use, metformin use was associated with a decreased risk of developing sepsis (adjusted odds ratio [OR] 0.80, 95% confidence interval [CI] 0.77-0.83, P < 0.001), but meglitinide (adjusted OR 1.32, 95% CI 1.25-1.40, P < 0.001) use was associated with the increased risk of developing sepsis. The risk for development of sepsis was also lower among current (adjusted OR 0.87, 95% CI 0.78-0.96) and recent (adjusted OR 0.83, 95% CI 0.73-0.94) thiazolidinedione users. Current or recent sulfonylurea use and dipeptidyl peptidase-4 inhibitor use were not significantly associated with the development of sepsis. Our results highlight the need to consider the potential pleiotropic effect of OADs against sepsis in addition to the lowering of blood glucose.
Collapse
Affiliation(s)
- Chia-Jen Shih
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Medicine, Taipei Veterans General Hospital, Yuanshan Branch, Yilan, Taiwan
| | - Yueh-Lin Wu
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Division of Nephrology, Department of Medicine, Taipei City Hospital, Zhongxiao Branch Branch, Taipei, Taiwan
| | - Pei-Wen Chao
- Department of Anesthesiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
- School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shu-Chen Kuo
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli County, Taiwan
- Division of Infectious Diseases, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chih-Yu Yang
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Szu-Yuan Li
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Shuo-Ming Ou
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yung-Tai Chen
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
- Division of Nephrology, Department of Medicine, Taipei City Hospital, Heping Fuyou Branch, Taipei, Taiwan
| |
Collapse
|
55
|
Liu X, Pang L, Sim SH, Goh KT, Ravikumar S, Win MS, Tan G, Cook AR, Fisher D, Chai LYA. Association of melioidosis incidence with rainfall and humidity, Singapore, 2003-2012. Emerg Infect Dis 2015; 21:159-62. [PMID: 25531547 PMCID: PMC4285244 DOI: 10.3201/eid2101.140042] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Soil has been considered the natural reservoir for the bacterium Burkholderia pseudomallei, which causes melioidosis. We examined 550 melioidosis cases that occurred during a 10-year period in the highly urbanized city of Singapore, where soil exposure is rare, and found that rainfall and humidity levels were associated with disease incidence.
Collapse
|
56
|
Conejero L, Potempa K, Graham CM, Spink N, Blankley S, Salguero FJ, Pankla-Sranujit R, Khaenam P, Banchereau JF, Pascual V, Chaussabel D, Lertmemongkolchai G, O'Garra A, Bancroft GJ. The Blood Transcriptome of Experimental Melioidosis Reflects Disease Severity and Shows Considerable Similarity with the Human Disease. THE JOURNAL OF IMMUNOLOGY 2015; 195:3248-3261. [PMID: 26311902 DOI: 10.4049/jimmunol.1500641] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/15/2015] [Indexed: 12/11/2022]
Abstract
Melioidosis, a severe human disease caused by the bacterium Burkholderia pseudomallei, has a wide spectrum of clinical manifestations ranging from acute septicemia to chronic localized illness or latent infection. Murine models have been widely used to study the pathogenesis of infection and to evaluate novel therapies or vaccines, but how faithfully they recapitulate the biology of human melioidosis at a molecular level is not known. In this study, mice were intranasally infected with either high or low doses of B. pseudomallei to generate either acute, chronic, or latent infection and host blood and tissue transcriptional profiles were generated. Acute infection was accompanied by a homogeneous signature associated with induction of multiple innate immune response pathways, such as IL-10, TREM1, and IFN signaling, largely found in both blood and tissue. The transcriptional profile in blood reflected the heterogeneity of chronic infection and quantitatively reflected the severity of disease. Genes associated with fibrosis and tissue remodeling, including matrix metalloproteases and collagen, were upregulated in chronically infected mice with severe disease. Transcriptional signatures of both acute and chronic melioidosis revealed upregulation of iNOS in tissue, consistent with the expression of IFN-γ, but also Arginase-1, a functional antagonist of the iNOS pathway, and was confirmed by immunohistochemistry. Comparison of these mouse blood datasets by pathway and modular analysis with the blood transcriptional signature of patients with melioidosis showed that many genes were similarly perturbed, including Arginase-1, IL-10, TREM1, and IFN signaling, revealing the common immune response occurring in both mice and humans.
Collapse
Affiliation(s)
- Laura Conejero
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Krzysztof Potempa
- The Francis Crick Institute, Mill Hill Laboratory, (formerly MRC National Institute for Medical Research), London, UK
| | - Christine M Graham
- The Francis Crick Institute, Mill Hill Laboratory, (formerly MRC National Institute for Medical Research), London, UK
| | - Natasha Spink
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Simon Blankley
- The Francis Crick Institute, Mill Hill Laboratory, (formerly MRC National Institute for Medical Research), London, UK
| | | | - Rungnapa Pankla-Sranujit
- The Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Thailand
| | - Prasong Khaenam
- The Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Thailand
| | | | - Virginia Pascual
- Baylor Institute for Immunology Research, Thousand Oaks, Dallas, Texas, USA
| | - Damien Chaussabel
- Damien Chaussabel, PhD, Director, Systems Biology Department, Sidra Medical and Research Center, Sidra Medical and Research Center, Al Nasr Tower, AL Corniche Street, Qatar Foundation ∣ PO Box 26999 ∣ Doha, Qatar
| | - Ganjana Lertmemongkolchai
- The Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Thailand
| | - Anne O'Garra
- The Francis Crick Institute, Mill Hill Laboratory, (formerly MRC National Institute for Medical Research), London, UK.,NHLI, St. Mary's Hospital, Imperial College, London, UK
| | - Gregory J Bancroft
- Immunology and Infection Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| |
Collapse
|
57
|
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
|
58
|
Garcia FADO, Rebouças JF, Balbino TQ, da Silva TG, de Carvalho-Júnior CHR, Cerqueira GS, Brito GADC, Viana GSDB. Pentoxifylline reduces the inflammatory process in diabetic rats: relationship with decreases of pro-inflammatory cytokines and inducible nitric oxide synthase. JOURNAL OF INFLAMMATION-LONDON 2015; 12:33. [PMID: 25922592 PMCID: PMC4411660 DOI: 10.1186/s12950-015-0080-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 04/15/2015] [Indexed: 12/18/2022]
Abstract
Studies suggest that inflammation is a key factor in the pathogenesis of diabetes mellitus. Pro-inflammatory cytokines, such as IL-6 and TNF-alpha, are produced by adipose tissue in large quantities, in obese and especially in diabetic individuals. Pentoxifylline (PTX) is a non-selective phosphodiesterase inhibitor with anti-inflammatory and antioxidant actions that may contribute to alleviate diabetes side effects, as neuropathy, retinopathy and nephropathy. This study aims to investigate PTX anti-inflammatory effects on the carrageenan-induced paw edema model, in alloxan-induced diabetic rats. Diabetic animals (male Wistar rats, 200–250 g) were daily treated with PTX (25, 50, 100 mg/kg, p.o.), glibenclamide (GLI, 5 mg/kg, p.o., as reference) or water, for 5 days. Afterwards, carrageenan-treated paws were dissected, their skin removed and the tissue used for preparation of homogenates and measurements of IL-6 and TNF-alpha by Elisa. Serum levels of nitrite were also determined and paw slices used for iNOS immunohistochemistry assays. We showed that diabetic rats presented an amplification of the inflammatory response, as related to non-diabetic rats, what was evident 48 h after the edema-induction. The PTX-treatment of diabetic rats reduced glycemia (as related to untreated-diabetic ones) and the paw edema. It also brought edema volumes to values similar to those of non-diabetic rats, at the same observation time. The increased TNF-alpha and IL-6 levels in paws of untreated-diabetic rats were reduced in diabetic animals after PTX treatments. Besides, the increased levels of nitrite in the serum of diabetic rats were also decreased by PTX. Furthermore, a higher number of iNOS immunostained cells was demonstrated in paw tissues from untreated-diabetic rats, as related to those of PTX-treated diabetic animals. Our results show that PTX reduces inflammatory parameters, as pro-inflammatory cytokines and iNOS expression, indicating the potential benefit of the drug for the treatment of diabetes and related pathologic conditions.
Collapse
Affiliation(s)
| | | | | | | | | | - Gilberto Santos Cerqueira
- Faculty of Medicine of the Federal University of Ceará, Rua Barbosa de Freitas, 130/1100, Fortaleza, CEP: 60170-020 Brazil
| | - Gerly Anne de Castro Brito
- Faculty of Medicine of the Federal University of Ceará, Rua Barbosa de Freitas, 130/1100, Fortaleza, CEP: 60170-020 Brazil
| | - Glauce Socorro de Barros Viana
- Faculty of Medicine Estácio of Juazeiro do Norte, Juazeiro do Norte, Brazil ; Faculty of Medicine of the Federal University of Ceará, Rua Barbosa de Freitas, 130/1100, Fortaleza, CEP: 60170-020 Brazil
| |
Collapse
|
59
|
Kimberly RP. The Road Traveled: Genomics and Biomarkers in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis. Arthritis Rheumatol 2015; 67:1700-2. [PMID: 25891203 DOI: 10.1002/art.39148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 04/07/2015] [Indexed: 11/06/2022]
|
60
|
Buddhisa S, Rinchai D, Ato M, Bancroft GJ, Lertmemongkolchai G. Programmed death ligand 1 on Burkholderia pseudomallei-infected human polymorphonuclear neutrophils impairs T cell functions. THE JOURNAL OF IMMUNOLOGY 2015; 194:4413-21. [PMID: 25801435 DOI: 10.4049/jimmunol.1402417] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 02/18/2015] [Indexed: 01/21/2023]
Abstract
Polymorphonuclear neutrophils (PMNs) are terminally differentiated cells that are involved in innate immune responses and form an early line of defense against pathogens. More recently, it has been shown that PMNs have immunosuppressive abilities on other immune cells. However, the effect of PMNs on T cell responses during bacterial infection remains to be determined. In this report, we examined the interaction of PMNs and T cells in response to infection with Burkholderia pseudomallei, the causative agent of human melioidosis. We observed that CD4(+) T cell proliferation and IFN-γ production in response to polyclonal activators is significantly inhibited by uninfected PMNs, and to a greater extent B. pseudomallei-infected PMNs. Programmed death ligand 1 (PD-L1), a known regulator of T cell activation, is increased in mRNA expression in the blood of patients and upon infection of PMNs in vitro. The increased expression of PD-L1 was correlated with the degree of T cell inhibition in individuals with type 2 diabetes, a major risk factor of melioidosis. In vitro, addition of anti-PD-L1 Abs blocked this inhibitory activity and restored proliferation of CD4(+) T cells and IFN-γ production, suggesting that PD-L1 on B. pseudomallei-infected PMNs is a regulatory molecule for the functions of T cells and may be involved in pathogenesis versus control of melioidosis.
Collapse
Affiliation(s)
- Surachat Buddhisa
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Darawan Rinchai
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Manabu Ato
- Department of Immunology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; and
| | - Gregory J Bancroft
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
| | - Ganjana Lertmemongkolchai
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand;
| |
Collapse
|
61
|
de Jong HK, Koh GCKW, Bulder I, Stephan F, Wiersinga WJ, Zeerleder SS. Diabetes-independent increase of factor VII-activating protease activation in patients with Gram-negative sepsis (melioidosis). J Thromb Haemost 2015; 13:41-6. [PMID: 25370187 PMCID: PMC4309501 DOI: 10.1111/jth.12776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Indexed: 12/22/2022]
Abstract
BACKGROUND The plasma protease factor VII-activating protease (FSAP) can release nucleosomes from late apoptotic cells. Nucleosomes are markers of cell death, and extracellular cell-free DNA has been suggested to play an important role in inflammation and has been demonstrated to correlate with severity and outcome in sepsis patients. OBJECTIVE To investigate FSAP activation in patients suffering from Burkholderia pseudomallei infection (melioidosis), an important cause of Gram-negative sepsis in Southeast Asia. As diabetes mellitus (DM) is the most important risk factor for both melioidosis and sepsis, we were also able to examine the role of DM in FSAP activation in this cohort of patients. METHODS In a prospective observational study, complexes of FSAP with α2 -antiplasmin (AP) were assayed in 44 patients with melioidosis, 34 of whom were classified as diabetic. Eighty-two healthy subjects served as controls (52 with DM and 30 without). RESULTS FSAP-AP complex levels were markedly elevated in patients as compared with controls. The FSAP level increased by 16.82 AU mL(-1) in patients with melioidosis after adjustment for the effect of DM in the regression model. As expected, FSAP activation was correlated with nucleosome release (slope = 0.74). No difference in FSAP activation on admission was seen between survivors and non-survivors, but the extent of FSAP activation correlated with stage of the disease; repeated testing during convalescence showed a return towards normal values (day 0 vs. day 28, 4.16 AU mL(-1) , 95% confidence interval [CI] 1.42-12.22). CONCLUSION Patients with Gram-negative sepsis caused by B. pseudomallei have abundant FSAP activation, which significantly correlates with stage of disease. The presence of DM, however, does not influence the extent of FSAP activation.
Collapse
Affiliation(s)
- H K de Jong
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of AmsterdamAmsterdam, the Netherlands
- Division of Infectious Diseases, Department of Medicine, Academic Medical CenterAmsterdam, the Netherlands
| | - G C K W Koh
- Department of Medicine, Addenbrooke's Hospital, University of CambridgeCambridge, UK
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol UniversityBangkok, Thailand
| | - I Bulder
- Department of Immunopathology, Sanquin ResearchAmsterdam, the Netherlands
| | - F Stephan
- Department of Immunopathology, Sanquin ResearchAmsterdam, the Netherlands
| | - W J Wiersinga
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, University of AmsterdamAmsterdam, the Netherlands
- Division of Infectious Diseases, Department of Medicine, Academic Medical CenterAmsterdam, the Netherlands
| | - S S Zeerleder
- Department of Immunopathology, Sanquin ResearchAmsterdam, the Netherlands
- Department of Hematology, Academic Medical CenterAmsterdam, the Netherlands
| |
Collapse
|
62
|
Moraco AH, Kornfeld H. Cell death and autophagy in tuberculosis. Semin Immunol 2014; 26:497-511. [PMID: 25453227 DOI: 10.1016/j.smim.2014.10.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 09/30/2014] [Accepted: 10/01/2014] [Indexed: 12/13/2022]
Abstract
Mycobacterium tuberculosis has succeeded in infecting one-third of the human race though inhibition or evasion of innate and adaptive immunity. The pathogen is a facultative intracellular parasite that uses the niche provided by mononuclear phagocytes for its advantage. Complex interactions determine whether the bacillus will or will not be delivered to acidified lysosomes, whether the host phagocyte will survive infection or die, and whether the timing and mode of cell death works to the advantage of the host or the pathogen. Here we discuss cell death and autophagy in TB. These fundamental processes of cell biology feature in all aspects of TB pathogenesis and may be exploited to the treatment or prevention of TB disease.
Collapse
Affiliation(s)
- Andrew H Moraco
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Hardy Kornfeld
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
| |
Collapse
|
63
|
York JM, Castellanos KJ, Cabay RJ, Fantuzzi G. Inhibition of the nucleotide-binding domain, leucine-rich containing family, pyrin-domain containing 3 inflammasome reduces the severity of experimentally induced acute pancreatitis in obese mice. Transl Res 2014; 164:259-69. [PMID: 25152324 PMCID: PMC4180798 DOI: 10.1016/j.trsl.2014.06.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/06/2014] [Accepted: 06/23/2014] [Indexed: 12/24/2022]
Abstract
Acute pancreatitis (AP), although most often a mild and self-limiting inflammatory disease, worsens to a characteristically necrotic severe acute pancreatitis (SAP) in about 20% of cases. Obesity, affecting more than one-third of American adults, is a risk factor for the development of SAP, but the exact mechanism of this association has not been identified. Coincidental with chronic low-grade inflammation, activation of the nucleotide-binding domain, leucine-rich containing family, pyrin-domain containing 3 (NLRP3) inflammasome increases with obesity. Lean mice genetically deficient in specific components of the NLRP3 inflammasome are protected from experimentally induced AP, indicating a direct involvement of this pathway in AP pathophysiology. We hypothesized that inhibition of the NLRP3 inflammasome with the sulfonylurea drug glyburide would reduce disease severity in obese mice with cerulein-induced SAP. Treatment with glyburide led to significantly reduced relative pancreatic mass and water content and less pancreatic damage and cell death in genetically obese ob/ob mice with SAP compared with vehicle-treated obese SAP mice. Glyburide administration in ob/ob mice with cerulein-induced SAP also resulted in significantly reduced serum levels of interleukin 6, lipase, and amylase and led to lower production of lipopolysaccharide-stimulated interleukin 1β release in cultured peritoneal cells, compared with vehicle-treated ob/ob mice with SAP. Together, these data indicate involvement of the NLRP3 inflammasome in obesity-associated SAP and expose the possible utility of its inhibition in prevention or treatment of SAP in obese individuals.
Collapse
Affiliation(s)
- Jason M York
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Ill.
| | - Karla J Castellanos
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Ill
| | - Robert J Cabay
- Department of Pathology, University of Illinois at Chicago, Chicago, Ill
| | - Giamila Fantuzzi
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Ill
| |
Collapse
|
64
|
de Jong HK, Koh GC, Achouiti A, van der Meer AJ, Bulder I, Stephan F, Roelofs JJ, Day NP, Peacock SJ, Zeerleder S, Wiersinga WJ. Neutrophil extracellular traps in the host defense against sepsis induced by Burkholderia pseudomallei (melioidosis). Intensive Care Med Exp 2014. [PMID: 26215706 PMCID: PMC4678137 DOI: 10.1186/s40635-014-0021-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background Neutrophil extracellular traps (NETs) are a central player in the host response to bacteria: neutrophils release extracellular DNA (nucleosomes) and neutrophil elastase to entrap and kill bacteria. We studied the role of NETs in Burkholderia pseudomallei infection (melioidosis), an important cause of Gram-negative sepsis in Southeast Asia. Methods In a prospective observational study, circulating nucleosomes and neutrophil elastase were assayed in 44 patients with Gram-negative sepsis caused by B. pseudomallei (melioidosis) and 82 controls. Functional assays included human neutrophil stimulation and killing assays and a murine model of B. pseudomallei infection in which NET function was compromised using DNase. Specified pathogen-free 8- to 12-week-old C57BL/6 mice were sacrificed post-infection to assess bacterial loads, inflammation, and pathology. Results Nucleosome and neutrophil elastase levels were markedly elevated in patients compared to controls. NETs killed B. pseudomallei effectively, and neutrophils stimulated with B. pseudomallei showed increased elastase and DNA release in a time- and dose-dependent matter. In mice, NET disruption with intravenous DNase administration resulted in decreased nucleosome levels. Although DNase treatment of mice resulted in diminished liver inflammation, no differences were observed in bacterial dissemination or systemic inflammation. Conclusion B. pseudomallei is a potent inducer of NETosis which was reflected by greatly increased levels of NET-related components in melioidosis patients. Although NETs exhibited antibacterial activity against B. pseudomallei, NET formation did not protect against bacterial dissemination and inflammation during B. pseudomallei-induced sepsis. Electronic supplementary material The online version of this article (doi:10.1186/s40635-014-0021-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Hanna K de Jong
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Meibergdreef 9, Room G2-132, Amsterdam, 1105 AZ, The Netherlands,
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
65
|
Sulphonylurea usage in melioidosis is associated with severe disease and suppressed immune response. PLoS Negl Trop Dis 2014; 8:e2795. [PMID: 24762472 PMCID: PMC3998927 DOI: 10.1371/journal.pntd.0002795] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 03/04/2014] [Indexed: 12/12/2022] Open
Abstract
Background Melioidosis is a problem in the developing tropical regions of Southeast Asia and Northern Australia where the the Gram negative saprophytic bacillus Burkholderia pseudomallei is endemic with the risk of fulminant septicaemia. While diabetes mellitus is a well-established risk factor for melioidiosis, little is known if specific hypoglycemic agents may differentially influence the susceptibility and clinical course of infection with B. pseudomallei (Bp). Methodology/Principal Findings In this cohort study, patients with pre-existing diabetes and melioidosis were retrospectively studied. Outcome measures: mortality, length of stay and development of complications (namely hypotension, intubation, renal failure and septicaemia) were studied in relation to prior diabetic treatment regimen. Peripheral blood mononuclear cells (PBMC) from diabetic patients and healthy PBMC primed with metformin, glyburide and insulin were stimulated with purified Bp antigens in vitro. Immune response and specific immune pathway mediators were studied to relate to the clinical findings mechanistically. Of 74 subjects, 44 (57.9%) had sulphonylurea-containing diabetic regimens. Patient receiving sulphonylureas had more severe septic complications (47.7% versus 16.7% p = 0.006), in particular, hypotension requiring intropes (p = 0.005). There was also a trend towards increased mortality in sulphonylurea-users (15.9% versus 3.3% p = 0.08). In-vitro, glyburide suppressed inflammatory cytokine production in a dose-dependent manner. An effect of the drug was the induction of IL-1R-associated kinase-M at the level of mRNA transcription. Conclusion/Significance Sulphonylurea treatment results in suppression of host inflammatory response and may put patients at higher risk for adverse outcomes in melioidosis. Melioidosis is a problem in the developing tropical regions of Southeast Asia and Northern Australia where the Gram negative bacillus Burkholderia pseudomallei can cause life-threatening infection. Diabetes mellitus is a recognised risk factor for melioidiosis; however little is known if commonly used anti-diabetic drugs may affect the clinical course of the disease. In this study, we found that patients who were receiving sulphonylureas for diabetic treatment had more severe septic complications requiring intensive care as well as increased risk of deaths. This may be attributable to the capacity of sulphonylureas in modulating the host immune response. We highlight caution in the prescription of this class of drug, which is popular due to its low cost and easy availability, especially in melioidosis-endemic tropical regions.
Collapse
|
66
|
Glibenclamide decreases ATP-induced intracellular calcium transient elevation via inhibiting reactive oxygen species and mitochondrial activity in macrophages. PLoS One 2014; 9:e89083. [PMID: 24558474 PMCID: PMC3928368 DOI: 10.1371/journal.pone.0089083] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 01/19/2014] [Indexed: 12/11/2022] Open
Abstract
Increasing evidence has revealed that glibenclamide has a wide range of anti-inflammatory effects. However, it is unclear whether glibenclamide can affect the resting and adenosine triphosphate (ATP)-induced intracellular calcium ([Ca2+]i) handling in Raw 264.7 macrophages. In the present study, [Ca2+]i transient, reactive oxygen species (ROS) and mitochondrial activity were measured by the high-speed TILLvisION digital imaging system using the indicators of Fura 2-am, DCFDA and rhodamine-123, respectively. We found that glibenclamide, pinacidil and other unselective K+ channel blockers had no effect on the resting [Ca2+]i of Raw 264.7 cells. Extracellular ATP (100 µM) induced [Ca2+]i transient elevation independent of extracellular Ca2+. The transient elevation was inhibited by an ROS scavenger (tiron) and mitochondria inhibitor (rotenone). Glibenclamide and 5-hydroxydecanoate (5-HD) also decreased ATP-induced [Ca2+]i transient elevation, but pinacidil and other unselective K+ channel blockers had no effect. Glibenclamide also decreased the peak of [Ca2+]i transient induced by extracellular thapsigargin (Tg, 1 µM). Furthermore, glibenclamide decreased intracellular ROS and mitochondrial activity. When pretreated with tiron and rotenone, glibenclamide could not decrease ATP, and Tg induced maximal [Ca2+]i transient further. We conclude that glibenclamide may inhibit ATP-induced [Ca2+]i transient elevation by blocking mitochondria KATP channels, resulting in decreased ROS generation and mitochondrial activity in Raw 264.7 macrophages.
Collapse
|
67
|
Glibenclamide reduces pro-inflammatory cytokine production by neutrophils of diabetes patients in response to bacterial infection. Sci Rep 2013; 3:3363. [PMID: 24285369 PMCID: PMC3842541 DOI: 10.1038/srep03363] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 11/12/2013] [Indexed: 12/31/2022] Open
Abstract
Type 2 diabetes mellitus is a major risk factor for melioidosis, which is caused by Burkholderia pseudomallei. Our previous study has shown that polymorphonuclear neutrophils (PMNs) from diabetic subjects exhibited decreased functions in response to B. pseudomallei. Here we investigated the mechanisms regulating cytokine secretion of PMNs from diabetic patients which might contribute to patient susceptibility to bacterial infections. Purified PMNs from diabetic patients who had been treated with glibenclamide (an ATP-sensitive potassium channel blocker for anti-diabetes therapy), showed reduction of interleukin (IL)-1β and IL-8 secretion when exposed to B. pseudomallei. Additionally, reduction of these pro-inflammatory cytokines occurred when PMNs from diabetic patients were treated in vitro with glibenclamide. These findings suggest that glibenclamide might be responsible for the increased susceptibility of diabetic patients, with poor glycemic control, to bacterial infections as a result of its effect on reducing IL-1β production by PMNs.
Collapse
|
68
|
Glyburide reduces bacterial dissemination in a mouse model of melioidosis. PLoS Negl Trop Dis 2013; 7:e2500. [PMID: 24147174 PMCID: PMC3798430 DOI: 10.1371/journal.pntd.0002500] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 09/09/2013] [Indexed: 12/27/2022] Open
Abstract
Background Burkholderia pseudomallei infection (melioidosis) is an important cause of community-acquired Gram-negative sepsis in Northeast Thailand, where it is associated with a ∼40% mortality rate despite antimicrobial chemotherapy. We showed in a previous cohort study that patients taking glyburide ( = glibenclamide) prior to admission have lower mortality and attenuated inflammatory responses compared to patients not taking glyburide. We sought to define the mechanism underlying this observation in a murine model of melioidosis. Methods Mice (C57BL/6) with streptozocin-induced diabetes were inoculated with ∼6×102 cfu B. pseudomallei intranasally, then treated with therapeutic ceftazidime (600 mg/kg intraperitoneally twice daily starting 24 h after inoculation) in order to mimic the clinical scenario. Glyburide (50 mg/kg) or vehicle was started 7 d before inoculation and continued until sacrifice. The minimum inhibitory concentration of glyburide for B. pseudomallei was determined by broth microdilution. We also examined the effect of glyburide on interleukin (IL) 1β by bone-marrow-derived macrophages (BMDM). Results Diabetic mice had increased susceptibility to melioidosis, with increased bacterial dissemination but no effect was seen of diabetes on inflammation compared to non-diabetic controls. Glyburide treatment did not affect glucose levels but was associated with reduced pulmonary cellular influx, reduced bacterial dissemination to both liver and spleen and reduced IL1β production when compared to untreated controls. Other cytokines were not different in glyburide-treated animals. There was no direct effect of glyburide on B. pseudomallei growth in vitro or in vivo. Glyburide directly reduced the secretion of IL1β by BMDMs in a dose-dependent fashion. Conclusions Diabetes increases the susceptibility to melioidosis. We further show, for the first time in any model of sepsis, that glyburide acts as an anti-inflammatory agent by reducing IL1β secretion accompanied by diminished cellular influx and reduced bacterial dissemination to distant organs. We found no evidence for a direct effect of glyburide on the bacterium. Burkholderia pseudomallei infection (also called melioidosis) is a common cause of bacterial infection in Northeast Thailand, where the mortality rate is 43% despite appropriate antibiotic treatment. We showed previously that patients taking glyburide ( = glibenclamide) prior to admission have lower mortality rates and lower levels of inflammation in the blood. In this study, we used a mouse model to better understand the mechanism underlying this observation. In this study, we used a mouse model of diabetes and infected the mice with B. pseudomallei. Half the mice were treated with glyburide and half were not. We also performed in vitro experiments to find the minimum concentration of glyburide that would inhibit the growth of B. pseudomallei. We found that glyburide treatment was associated with reduced inflammation (as measured by the flow of cells into the lungs and by interleukin-1β production) and reduced spread of the bacterium to liver and spleen when compared to untreated controls. There was no direct effect of glyburide on B. pseudomallei growth in vitro or in vivo. Because the effect of glyburide is on the host and not on the bacterium, it is possible that this effect will be seen in other causes of sepsis, not just melioidosis.
Collapse
|
69
|
dos Santos RMS, Oliveira SM, Silva CR, Hoffmeister C, Ferreira J, Assreuy J. Anti-nociceptive and anti-edematogenic effects of glibenclamide in a model of acute gouty attack in rats. Inflamm Res 2013; 62:617-25. [PMID: 23543229 DOI: 10.1007/s00011-013-0615-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 01/14/2013] [Accepted: 03/18/2013] [Indexed: 10/27/2022] Open
Abstract
OBJECTIVE AND DESIGN We investigated the effect of glibenclamide on inflammatory parameters in a model of acute gouty attack in rats. TREATMENT Intra-articular injection of 50 μl of monosodium urate (MSU) crystals (1.25 mg/site) was used to induce gout-related inflammation. The effects of glibenclamide (1-10 mg/kg, s.c.) or dexamethasone (8 mg/kg, s.c., positive control) were assessed on several inflammation parameters. METHODS Spontaneous nociception assessment, edema measurement, total and differential leucocyte counts, interleukin (IL)-1β release, prostaglandin E2 production and determination of blood glucose levels were analyzed. Peritoneal macrophages were incubated with MSU and levels of IL-1β were measured. Statistical significance was assessed by one- or two-way analysis of variance. RESULTS Glibenclamide (3 mg/kg) or dexamethasone (8 mg/kg) prevented nociception and edema induced by MSU injection in rats. Glibenclamide did not affect leukocyte infiltration, IL-1β release and PGE2 production, but only reduced IL-1β production by MSU-stimulated macrophages at very high concentration (200 μM). Dexamethasone significantly reduced leukocyte infiltration, IL-1β release and PGE2 production. Glibenclamide reduced whereas dexamethasone increased blood glucose levels of MSU-injected rats. CONCLUSIONS Glibenclamide reduced nociception and edema, but not leukocyte infiltration, IL-1β release and PGE2 production. However, its substantial effect on nociception and edema suggests that glibenclamide can be an interesting option as an adjuvant treatment for pain induced by acute attacks of gout.
Collapse
Affiliation(s)
- Rosane M S dos Santos
- Laboratório de Neurotoxicidade e Psicofarmacologia, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | | | | | | | | | | |
Collapse
|
70
|
Grant RW, Dixit VD. Mechanisms of disease: inflammasome activation and the development of type 2 diabetes. Front Immunol 2013; 4:50. [PMID: 23483669 PMCID: PMC3592198 DOI: 10.3389/fimmu.2013.00050] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/10/2013] [Indexed: 12/23/2022] Open
Abstract
Over the recent past, the importance of aberrant immune cell activation as one of the contributing mechanisms to the development of insulin-resistance and type 2 diabetes (T2D) has been recognized. Among the panoply of pro-inflammatory cytokines that are linked to chronic metabolic diseases, new data suggests that interleukin-1β (IL-1β) may play an important role in initiating and sustaining inflammation-induced organ dysfunction in T2D. Therefore, factors that control secretion of bioactive IL-1β have therapeutic implications. In this regard, the identification of multiprotein scaffolding complexes, "inflammasomes," has been a great advance in our understanding of this process. The secretion of bioactive IL-1β is predominantly controlled by activation of caspase-1 through assembly of a multiprotein scaffold, "inflammasome" that is composed of NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) ASC (apoptosis associated speck-like protein containing a CARD) and procaspase-1. The NLRP3 inflammasome appears to be an important sensor of metabolic dysregulation and controls obesity-associated insulin resistance and pancreatic beta cell dysfunction. Initial clinical "proof of concept" studies suggest that blocking IL-1β may favorably modulate factors related to development and treatment of T2D. However, this potential therapeutic approach remains to be fully substantiated through phase-II clinical studies. Here, we outline the new immunological mechanisms that link metabolic dysfunction to the emergence of chronic inflammation and discuss the opportunities and challenges of future therapeutic approaches to dampen NLRP3 inflammasome activation or IL-1β signaling for controlling type 2 diabetes.
Collapse
Affiliation(s)
- Ryan W Grant
- Immunobiology Laboratory, Pennington Biomedical Research Center, Louisiana State University System Baton Rouge, LA, USA
| | | |
Collapse
|
71
|
Koh GCKW, Schreiber MF, Bautista R, Maude RR, Dunachie S, Limmathurotsakul D, Day NPJ, Dougan G, Peacock SJ. Host responses to melioidosis and tuberculosis are both dominated by interferon-mediated signaling. PLoS One 2013; 8:e54961. [PMID: 23383015 PMCID: PMC3558488 DOI: 10.1371/journal.pone.0054961] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 12/18/2012] [Indexed: 01/08/2023] Open
Abstract
Melioidosis (Burkholderia pseudomallei infection) is a common cause of community-acquired sepsis in Northeast Thailand and northern Australia. B. pseudomallei is a soil saprophyte endemic to Southeast Asia and northern Australia. The clinical presentation of melioidosis may mimic tuberculosis (both cause chronic suppurative lesions unresponsive to conventional antibiotics and both commonly affect the lungs). The two diseases have overlapping risk profiles (e.g., diabetes, corticosteroid use), and both B. pseudomallei and Mycobacterium tuberculosis are intracellular pathogens. There are however important differences: the majority of melioidosis cases are acute, not chronic, and present with severe sepsis and a mortality rate that approaches 50% despite appropriate antimicrobial therapy. By contrast, tuberculosis is characteristically a chronic illness with mortality <2% with appropriate antimicrobial chemotherapy. We examined the gene expression profiles of total peripheral leukocytes in two cohorts of patients, one with acute melioidosis (30 patients and 30 controls) and another with tuberculosis (20 patients and 24 controls). Interferon-mediated responses dominate the host response to both infections, and both type 1 and type 2 interferon responses are important. An 86-gene signature previously thought to be specific for tuberculosis is also found in melioidosis. We conclude that the host responses to melioidosis and to tuberculosis are similar: both are dominated by interferon-signalling pathways and this similarity means gene expression signatures from whole blood do not distinguish between these two diseases.
Collapse
Affiliation(s)
- Gavin C K W Koh
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom.
| | | | | | | | | | | | | | | | | |
Collapse
|
72
|
Schweizer HP. Mechanisms of antibiotic resistance in Burkholderia pseudomallei: implications for treatment of melioidosis. Future Microbiol 2012; 7:1389-99. [PMID: 23231488 PMCID: PMC3568953 DOI: 10.2217/fmb.12.116] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Burkholderia pseudomallei is the etiologic agent of melioidosis. This multifaceted disease is difficult to treat, resulting in high morbidity and mortality. Treatment of B. pseudomallei infections is lengthy and necessitates an intensive phase (parenteral ceftazidime, amoxicillin-clavulanic acid or meropenem) and an eradication phase (oral trimethoprim-sulfamethoxazole). The main resistance mechanisms affecting these antibiotics include enzymatic inactivation, target deletion and efflux from the cell, and are mediated by chromosomally encoded genes. Overproduction and mutations in the class A PenA β-lactamase cause ceftazidime and amoxicillin-clavulanic acid resistance. Deletion of the penicillin binding protein 3 results in ceftazidime resistance. BpeEF-OprC efflux pump expression causes trimethoprim and trimethoprim-sulfamethoxazole resistance. Although resistance is still relatively rare, therapeutic efficacies may be compromised by resistance emergence due to increased use of antibiotics in endemic regions. Novel agents and therapeutic strategies are being tested and, in some instances, show promise as anti-B. pseudomallei infectives.
Collapse
Affiliation(s)
- Herbert P Schweizer
- Colorado State University, Department of Microbiology, Immunology & Pathology, IDRC at Foothills Campus, 0922 Campus Delivery, Fort Collins, CO 80523, USA.
| |
Collapse
|
73
|
Koh GCKW, Vlaar APJ, Hofstra JJ, de Jong HK, van Nierop S, Peacock SJ, Wiersinga WJ, Schultz MJ, Juffermans NP. In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury: a cohort study. Crit Care Med 2012; 40:1835-43. [PMID: 22488007 PMCID: PMC3379571 DOI: 10.1097/ccm.0b013e31824e1696] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Patients with diabetes mellitus form 23%-30% of published cohorts of critically ill patients. Conflicting published evidence links diabetes mellitus to both higher and lower mortality. Other cohort studies suggest that diabetes mellitus protects against acute lung injury. We hypothesized that diabetes mellitus is an independent risk factor for mortality. We further hypothesized that diabetes mellitus is a risk factor for cardiac overload and not for acute lung injury. DESIGN Retrospective cohort study. SETTING The intensive care unit of a tertiary referral hospital. PATIENTS From November 1, 2004, to October 1, 2007, a cohort of patients admitted ≥48 hrs to the intensive care unit. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Of 2,013 patients, 317 had diabetes mellitus. Ninety-day mortality was higher in the diabetes mellitus patients compared to patients without diabetes mellitus (hazard ratio 1.53, 95% confidence interval 1.29-1.80). This association strengthened after adjusting for confounders and for medication (hazard ratio 1.53, 95% confidence interval 1.07-2.17).We found no association between diabetes mellitus and acute lung injury (relative risk ratio 1.01, 95% confidence interval 0.78-1.32; adjusted relative risk ratio 0.99, 95% confidence interval 0.75-1.31), but diabetes mellitus was a risk factor for cardiac overload (relative risk ratio 1.91, 95% confidence interval 1.30-2.81; adjusted relative risk ratio 1.45, 95% confidence interval 0.97-2.18). Statins were associated with both a reduced risk of mortality (hazard ratio 0.74, 95% confidence interval 0.63-0.87; adjusted hazard ratio 0.53, 95% confidence interval 0.44-0.64) and a decreased risk of developing acute lung injury (relative risk ratio 0.71, 95% confidence interval 0.56-0.89; adjusted relative risk ratio 0.61, 95% confidence interval 0.47-0.79). CONCLUSIONS Diabetes mellitus is an independent risk factor for mortality in critically ill patients and failure to adjust for statins underestimates the size of this association. Diabetes mellitus is not associated with acute lung injury but is associated with cardiac overload. A diagnosis of cardiac overload excludes a diagnosis of acute lung injury. Investigators who do not account for cardiac overload as a competing alternative outcome may therefore falsely conclude that diabetes mellitus protects from acute lung injury.
Collapse
|
74
|
López-Castejón G, Pelegrín P. Current status of inflammasome blockers as anti-inflammatory drugs. Expert Opin Investig Drugs 2012; 21:995-1007. [PMID: 22612568 DOI: 10.1517/13543784.2012.690032] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The inflammasomes have emerged as key mediators of inflammation and immunity, yet clinical application of this knowledge has been limited by a lack of specific and drug-like antagonists. Recent studies using inflammasome knockout mice have shown that different inflammasomes control immunity in different pathologies. Drug-like antagonists acting up- or down-stream of the inflammasome pathway have been successfully used in clinics as important therapeutics to treat different inflammatory diseases. AREAS COVERED The current literature has been reviewed on the role of inflammasomes in inflammatory disease, focusing on potential therapeutic applications of selective inflammasome antagonists as anti-inflammatory agents. Particular emphasis has been placed on the potential role of the different inflammasomes in common inflammatory diseases. The latest clinical developments for drugs targeting inflammasome pathways are covered. EXPERT OPINION Recent studies using inflammasome knockout mice suggest its importance as a potential therapeutic target for the treatment of inflammatory disease. However, efficacious antagonists for the inflammasome for use in clinical studies are still at an early stage of development. Developing selective inflammasome antagonists is a challenge that if met, offers promise for the treatment of chronic inflammatory diseases. Major developments in this area will include the identification of reliable high-throughput screening methods for compounds directly targeting inflammasome assembly.
Collapse
Affiliation(s)
- Gloria López-Castejón
- University of Manchester, Faculty of Life Science, AV Hill Building, 2.021, Manchester, M13 9PT, UK
| | | |
Collapse
|
75
|
Tan KS, Lee KO, Low KC, Gamage AM, Liu Y, Tan GYG, Koh HQV, Alonso S, Gan YH. Glutathione deficiency in type 2 diabetes impairs cytokine responses and control of intracellular bacteria. J Clin Invest 2012; 122:2289-300. [PMID: 22546856 DOI: 10.1172/jci57817] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 03/07/2012] [Indexed: 11/17/2022] Open
Abstract
Individuals with type 2 diabetes are at increased risk of acquiring melioidosis, a disease caused by Burkholderia pseudomallei infection. Although up to half of melioidosis patients have underlying diabetes, the mechanisms involved in this increased susceptibility are unknown. We found that B. pseudomallei-infected PBMCs from diabetic patients were impaired in IL-12p70 production, which resulted in decreased IFN-γ induction and poor bacterial killing. The defect was specific to the IL-12-IFN-γ axis. Defective IL-12 production was also observed during Mycobacterium tuberculosis infection, in which diabetes is likewise known to be a strong risk factor. In contrast, IL-12 production in diabetic cells was not affected upon Salmonella enterica infection or in response to TLR2, -3, -4, and -5 ligands. Poor IL-12 production correlated with a deficiency in intracellular reduced glutathione (GSH) concentrations in diabetic patients. Addition of GSH or N-acetylcysteine to PBMCs selectively restored IL-12 and IFN-γ production and improved bacterial killing. Furthermore, the depletion of GSH in mice led to increased susceptibility to melioidosis, reduced production of IL-12p70, and poorer disease outcome. Our data thus establish a link between GSH deficiency in diabetes and increased susceptibility to melioidosis that may open up new therapeutic avenues to protect diabetic patients against some intracellular bacterial pathogens.
Collapse
Affiliation(s)
- Kai Soo Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | | | | | | | | | | | | | | |
Collapse
|
76
|
Chin CY, Monack DM, Nathan S. Delayed activation of host innate immune pathways in streptozotocin-induced diabetic hosts leads to more severe disease during infection with Burkholderia pseudomallei. Immunology 2012; 135:312-32. [PMID: 22136109 DOI: 10.1111/j.1365-2567.2011.03544.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Diabetes mellitus is a predisposing factor of melioidosis, contributing to higher mortality rates in diabetics infected with Burkholderia pseudomallei. To investigate how diabetes alters the inflammatory response, we established a streptozotocin (STZ) -induced diabetic murine acute-phase melioidosis model. Viable B. pseudomallei cells were consistently detected in the blood, liver and spleen during the 42-hr course of infection but the hyperglycaemic environment did not increase the bacterial burden. However, after 24 hr, granulocyte counts increased in response to infection, whereas blood glucose concentrations decreased over the course of infection. A genome-wide expression analysis of the STZ-diabetic murine acute melioidosis liver identified ~1000 genes whose expression was altered in the STZ-diabetic mice. The STZ-diabetic host transcriptional response was compared with the normoglycaemic host transcriptional response recently reported by our group. The microarray data suggest that the presence of elevated glucose levels impairs the host innate immune system by delaying the identification and recognition of B. pseudomallei surface structures. Consequently, the host is unable to activate the appropriate innate immune response over time, which may explain the increased susceptibility to melioidosis in the STZ-diabetic host. Nevertheless, a general 'alarm signal' of infection as well as defence programmes are still triggered by the STZ-diabetic host, although only 24 hr after infection. In summary, this study demonstrates that in the face of a B. pseudomallei acute infection, poor glycaemic control impaired innate responses during the early stages of B. pseudomallei infection, contributing to the increased susceptibility of STZ-induced diabetics to this fatal disease.
Collapse
Affiliation(s)
- Chui-Yoke Chin
- School of Biosciences and Biotechnology, Universiti Kebangsaan Malaysia, Selangor, Malaysia
| | | | | |
Collapse
|
77
|
Burkholderia pseudomallei triggers altered inflammatory profiles in a whole-blood model of type 2 diabetes-melioidosis comorbidity. Infect Immun 2012; 80:2089-99. [PMID: 22473609 DOI: 10.1128/iai.00212-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Melioidosis is a potentially fatal disease caused by the bacterium Burkholderia pseudomallei. Type 2 diabetes (T2D) is the most common comorbidity associated with melioidosis. B. pseudomallei isolates from melioidosis patients with T2D are less virulent in animal models than those from patients with melioidosis and no identifiable risk factors. We developed an ex vivo whole-blood assay as a tool for comparison of early inflammatory profiles generated by T2D and nondiabetic (ND) individuals in response to a B. pseudomallei strain of low virulence. Peripheral blood from individuals with T2D, with either poorly controlled glycemia (PC-T2D [n = 6]) or well-controlled glycemia (WC-T2D [n = 8]), and healthy ND (n = 13) individuals was stimulated with B. pseudomallei. Oxidative burst, myeloperoxidase (MPO) release, expression of pathogen recognition receptors (TLR2, TLR4, and CD14), and activation markers (CD11b and HLA-DR) were measured on polymorphonuclear (PMN) leukocytes and monocytes. Concentrations of plasma inflammatory cytokine (interleukin-6 [IL-6], IL-12p70, tumor necrosis factor alpha [TNF-α], monocyte chemoattractant protein 1 [MCP-1], IL-8, IL-1β, and IL-10) were also determined. Following stimulation, oxidative burst and MPO levels were significantly elevated in blood from PC-T2D subjects compared to controls. Differences were also observed in expression of Toll-like receptor 2 (TLR2), CD14, and CD11b on phagocytes from T2D and ND individuals. Levels of IL-12p70, MCP-1, and IL-8 were significantly elevated in blood from PC-T2D subjects compared to ND individuals. Notably, differential inflammatory responses of PC-T2D, WC-T2D, and ND individuals to B. pseudomallei occur independently of bacterial load and confirm the efficacy of this model of T2D-melioidosis comorbidity as a tool for investigation of dysregulated PMN and monocyte responses to B. pseudomallei underlying susceptibility of T2D individuals to melioidosis.
Collapse
|
78
|
Koh GCKW, Peacock SJ, van der Poll T, Wiersinga WJ. The impact of diabetes on the pathogenesis of sepsis. Eur J Clin Microbiol Infect Dis 2012; 31:379-88. [PMID: 21805196 PMCID: PMC3303037 DOI: 10.1007/s10096-011-1337-4] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 06/21/2011] [Indexed: 02/06/2023]
Abstract
Diabetes is associated with an increased susceptibility to infection and sepsis. Conflicting data exist on whether the mortality of patients with sepsis is influenced by the presence of diabetes, fuelling the ongoing debate on the benefit of tight glucose regulation in patients with sepsis. The main reason for which diabetes predisposes to infection appears to be abnormalities of the host response, particularly in neutrophil chemotaxis, adhesion and intracellular killing, defects that have been attributed to the effect of hyperglycaemia. There is also evidence for defects in humoral immunity, and this may play a larger role than previously recognised. We review the literature on the immune response in diabetes and its potential contribution to the pathogenesis of sepsis. In addition, the effect of diabetes treatment on the immune response is discussed, with specific reference to insulin, metformin, sulphonylureas and thiazolidinediones.
Collapse
Affiliation(s)
- G C K W Koh
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK.
| | | | | | | |
Collapse
|
79
|
Sanz D, Claramunt RM, Alkorta I, Sánchez-Sanz G, Elguero J. The structure of glibenclamide in the solid state. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:246-255. [PMID: 22383432 DOI: 10.1002/mrc.2868] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 10/26/2011] [Accepted: 11/06/2011] [Indexed: 05/31/2023]
Abstract
The structure of glibenclamide, 5-chloro-N-(2-{4-[(cyclohexylamino)carbonyl] aminosulfonyl}phenyl) ethyl)-2-methoxybenzamide, an important antidiabetic drug, has been studied both in solution and in the solid state by a combination of NMR spectroscopy and theoretical calculations. The possibility that glibenclamide suffers a tautomerization under melting to afford a desmotrope was rejected.
Collapse
Affiliation(s)
- Dionisia Sanz
- Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain.
| | | | | | | | | |
Collapse
|
80
|
Abstract
Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is an important cause of community-acquired sepsis in Southeast Asia and northern Australia. An important controller of the immune system is the pleiotropic cytokine transforming growth factor β (TGF-β), of which Smad2 and Smad3 are the major signal transducers. In this study, we aimed to characterize TGF-β expression and function in experimental melioidosis. TGF-β expression was determined in 33 patients with culture-proven infection with B. pseudomallei and 30 healthy controls. We found that plasma TGF-β concentrations were strongly elevated during melioidosis. In line with this finding, TGF-β expression in C57BL/6 mice intranasally inoculated with B. pseudomallei was enhanced as well. To assess the role of TGF-β, we inhibited TGF-β using a selective murine TGF-β antibody. Treatment of mice with anti-TGF-β antibody resulted in decreased lung Smad2 phosphorylation. TGF-β blockade appeared to be protective: mice treated with anti-TGF-β antibody and subsequently infected with B. pseudomallei showed diminished bacterial loads. Moreover, less distant organ injury was observed in anti-TGF-β treated mice as shown by reduced blood urea nitrogen (BUN) and aspartate transaminase (AST) values. However, anti-TGF-β treatment did not have an effect on survival. In conclusion, TGF-β is upregulated during B. pseudomallei infection and plays a limited but proinflammatory role during experimental melioidosis.
Collapse
|
81
|
Youm YH, Kanneganti TD, Vandanmagsar B, Zhu X, Ravussin A, Adijiang A, Owen JS, Thomas MJ, Francis J, Parks JS, Dixit VD. The Nlrp3 inflammasome promotes age-related thymic demise and immunosenescence. Cell Rep 2012; 1:56-68. [PMID: 22832107 DOI: 10.1016/j.celrep.2011.11.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 09/07/2011] [Accepted: 11/22/2011] [Indexed: 11/30/2022] Open
Abstract
The collapse of thymic stromal cell microenvironment with age and resultant inability of the thymus to produce naive T cells contributes to lower immune-surveillance in the elderly. Here we show that age-related increase in 'lipotoxic danger signals' such as free cholesterol (FC) and ceramides, leads to thymic caspase-1 activation via the Nlrp3 inflammasome. Elimination of Nlrp3 and Asc, a critical adaptor required for inflammasome assembly, reduces age-related thymic atrophy and results in an increase in cortical thymic epithelial cells, T cell progenitors and maintenance of T cell repertoire diversity. Using a mouse model of irradiation and hematopoietic stem cell transplantation (HSCT), we show that deletion of the Nlrp3 inflammasome accelerates T cell reconstitution and immune recovery in middle-aged animals. Collectively, these data demonstrate that lowering inflammasome-dependent caspase-1 activation increases thymic lymphopoiesis and suggest that Nlrp3 inflammasome inhibitors may aid the re-establishment of a diverse T cell repertoire in middle-aged or elderly patients undergoing HSCT.
Collapse
Affiliation(s)
- Yun-Hee Youm
- Immunobiology Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
82
|
Kebaier C, Chamberland RR, Allen IC, Gao X, Broglie PM, Hall JD, Jania C, Doerschuk CM, Tilley SL, Duncan JA. Staphylococcus aureus α-hemolysin mediates virulence in a murine model of severe pneumonia through activation of the NLRP3 inflammasome. J Infect Dis 2012; 205:807-17. [PMID: 22279123 DOI: 10.1093/infdis/jir846] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Staphylococcus aureus is a dangerous pathogen that can cause necrotizing infections characterized by massive inflammatory responses and tissue destruction. Staphylococcal α-hemolysin is an essential virulence factor in severe S. aureus pneumonia. It activates the nucleotide-binding domain and leucine-rich repeat containing gene family, pyrin domain containing 3 (NLRP3) inflammasome to induce production of interleukin-1β and programmed necrotic cell death. We sought to determine the role of α-hemolysin-mediated activation of NLRP3 in the pathogenesis of S. aureus pneumonia. We show that α-hemolysin activates the NLRP3 inflammasome during S. aureus pneumonia, inducing necrotic pulmonary injury. Moreover, Nlrp3(-/-) mice have less-severe pneumonia. Pulmonary injury induced by isolated α-hemolysin or live S. aureus is independent of interleukin-1β signaling, implicating NLRP3-induced necrosis in the pathogenesis of severe infection. This work demonstrates the exploitation of host inflammatory signaling by S. aureus and suggests the NLRP3 inflammasome as a potential target for pharmacologic interventions in severe S. aureus infections.
Collapse
Affiliation(s)
- Chahnaz Kebaier
- Department of Medicine, Division of Infectious Diseases, University of North Carolina, Chapel Hill, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
83
|
Youm YH, Adijiang A, Vandanmagsar B, Burk D, Ravussin A, Dixit VD. Elimination of the NLRP3-ASC inflammasome protects against chronic obesity-induced pancreatic damage. Endocrinology 2011; 152:4039-45. [PMID: 21862613 PMCID: PMC3199005 DOI: 10.1210/en.2011-1326] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Clinical evidence that the blockade of IL-1β in type-2 diabetic patients improves glycemia is indicative of an autoinflammatory mechanism that may trigger adiposity-driven pancreatic damage. IL-1β is a key contributor to the obesity-induced inflammation and subsequent insulin resistance, pancreatic β-cell dysfunction, and the onset of type 2 diabetes. Our previous studies demonstrated that the ceramides activate the Nod-like receptor family, pyrin domain containing 3 (Nlrp3) inflammasome to cause the generation of mature IL-1β and ablation of the Nlrp3 inflammasome in diet-induced obesity improves insulin signaling. However, it remains unclear whether the posttranslational processing of active IL-1β in pancreas is regulated by the NLRP3 inflammasome or whether the alternate mechanisms play a dominant role in chronic obesity-induced pancreatic β-cell exhaustion. Here we show that loss of ASC, a critical adaptor required for the assembly of the NLRP3 and absent in melanoma 2 inflammasome substantially improves the insulin action. Surprisingly, despite lower insulin resistance in the chronically obese NLRP3 and ASC knockout mice, the insulin levels were substantially higher when the inflammasome pathway was eliminated. The obesity-induced increase in maturation of pancreatic IL-1β and pancreatic islet fibrosis was dependent on the NLRP3 inflammasome activation. Furthermore, elimination of NLRP3 inflammasome protected the pancreatic β-cells from cell death caused by long-term high-fat feeding during obesity with significant increase in the size of the islets of Langerhans. Collectively, this study provides direct in vivo evidence that activation of the NLRP3 inflammasome in diet-induced obesity is a critical trigger in causing pancreatic damage and is an important mechanism of progression toward type 2 diabetes.
Collapse
Affiliation(s)
- Yun-Hee Youm
- Laboratory of Neuroendocrine-Immunology, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, Louisiana 70808, USA
| | | | | | | | | | | |
Collapse
|
84
|
Hodgson KA, Morris JL, Feterl ML, Govan BL, Ketheesan N. Altered macrophage function is associated with severe Burkholderia pseudomallei infection in a murine model of type 2 diabetes. Microbes Infect 2011; 13:1177-84. [PMID: 21835260 DOI: 10.1016/j.micinf.2011.07.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Revised: 07/13/2011] [Accepted: 07/21/2011] [Indexed: 12/19/2022]
Abstract
This study used a murine model of type 2 diabetes (BKS.Cg-Dock7(m) +/+Lepr(db)/J mice) to investigate the inflammatory and cellular mechanisms predisposing to Burkholderia pseudomallei infection and co-morbid diabetes. Homozygous db/db (diabetic) mice developed extreme obesity, dyslipidaemia and glucose intolerance leading to hyperglycaemia and overt type 2 diabetes. Compared to their heterozygous db/+ (non-diabetic) littermates, diabetic mice rapidly succumbed to subcutaneous B. pseudomallei infection, paralleled by severe hypoglycaemia and increased expression of the proinflammatory cytokines, tumour necrosis factor (TNF)-α and interleukin (IL)-1β, in the spleen, despite comparable bacterial loads in the spleen of non-diabetic mice. Neutrophil oxidative burst and dendritic cell uptake and killing of B. pseudomallei were similar between diabetic and non-diabetic mice. Compared to peritoneal macrophages from non-diabetic mice, macrophages from diabetic mice were unable to contain and kill B. pseudomallei. Functional differences between macrophages of diabetic and non-diabetic mice toward B. pseudomallei may contribute to rapid dissemination and more severe disease progression in hosts with co-morbid type 2 diabetes.
Collapse
Affiliation(s)
- Kelly A Hodgson
- Microbiology and Immunology, School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | | | | | | | | |
Collapse
|