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Role of Nephronectin in Pathophysiology of Silicosis. Int J Mol Sci 2019; 20:ijms20102581. [PMID: 31130697 PMCID: PMC6566895 DOI: 10.3390/ijms20102581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/16/2019] [Accepted: 05/25/2019] [Indexed: 01/11/2023] Open
Abstract
Silicosis is a typical form of pneumoconiosis and is characterized as a type of lung fibrosis. Silica particles are captured and recognized upon by alveolar macrophages via the macrophage receptor with collagenous structure (MARCO) scavenger receptor, and thereafter the inflammasome is activated. Thereafter, various chemokines/cytokines play their roles to eventually form fibrosis. Additionally, silica particles chronically activate T helper cells which sets the background for the formation of silicosis-associated autoimmune disturbances. The occurrence and progression of lung fibrosis, the extracellular matrix-related molecules such as integrins and their ligands including fibronectin, vitronectin, laminin, and collagens, all play important roles. Here, the roles of these molecules in silicosis-related lung fibrosis are reviewed from the literature. Additionally, the measurement of serum nephronectin (Npnt), a new member of the integrin family of ligands, is discussed, together with investigations attempting to delineate the role of Npnt in silica-induced lung fibrosis. Serum Npnt was found to be higher in silicosis patients compared to healthy volunteers and seems to play a role in the progression of fibrosis with other cytokines. Therefore, serum Npnt levels may be employed as a suitable marker to monitor the progression of fibrosis in silicosis patients.
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Pu Q, Gan C, Li R, Li Y, Tan S, Li X, Wei Y, Lan L, Deng X, Liang H, Ma F, Wu M. Atg7 Deficiency Intensifies Inflammasome Activation and Pyroptosis in Pseudomonas Sepsis. THE JOURNAL OF IMMUNOLOGY 2017; 198:3205-3213. [PMID: 28258192 DOI: 10.4049/jimmunol.1601196] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 02/09/2017] [Indexed: 02/05/2023]
Abstract
Sepsis is a severe and complicated syndrome that is characterized by dysregulation of host inflammatory responses and organ failure, with high morbidity and mortality. The literature implies that autophagy is a crucial regulator of inflammation in sepsis. In this article, we report that autophagy-related protein 7 (Atg7) is involved in inflammasome activation in Pseudomonas aeruginosa abdominal infection. Following i.p. challenge with P. aeruginosa, atg7fl/fl mice showed impaired pathogen clearance, decreased survival, and widespread dissemination of bacteria into the blood and lung tissue compared with wild-type mice. The septic atg7fl/fl mice also exhibited elevated neutrophil infiltration and severe lung injury. Loss of Atg7 resulted in increased production of IL-1β and pyroptosis, consistent with enhanced inflammasome activation. Furthermore, we demonstrated that P. aeruginosa flagellin is a chief trigger of inflammasome activation in the sepsis model. Collectively, our results provide insight into innate immunity and inflammasome activation in sepsis.
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Affiliation(s)
- Qinqin Pu
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.,Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Changpei Gan
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.,Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Rongpeng Li
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203.,Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University, Xuzhou, Jiangsu 221116, People's Republic of China
| | - Yi Li
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.,Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Shirui Tan
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Xuefeng Li
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.,Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Yuquan Wei
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Lefu Lan
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Pudong Xinqu, Shanghai Shi 201203, People's Republic of China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShangXi 710069, People's Republic of China; and
| | - Feng Ma
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, Sichuan 610052, People's Republic of China
| | - Min Wu
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China; .,Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
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Li X, He S, Li R, Zhou X, Zhang S, Yu M, Ye Y, Wang Y, Huang C, Wu M. Pseudomonas aeruginosa infection augments inflammation through miR-301b repression of c-Myb-mediated immune activation and infiltration. Nat Microbiol 2016; 1:16132. [PMID: 27670114 PMCID: PMC5061341 DOI: 10.1038/nmicrobiol.2016.132] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 07/05/2016] [Indexed: 02/05/2023]
Abstract
microRNAs (miRNAs) play critical roles in various biological processes including cell proliferation, development, and host defense. However, the molecular mechanism for miRNAs in regulating bacterial-induced inflammation remains largely unclear. Here we report that miR-301b augments pro-inflammatory response during pulmonary infection and caffeine (CAF) suppresses miR-301b’s effect and thereby augmenting respiratory immunity. LPS treatment or Pseudomonas aeruginosa infection induces miR-301b expression via a TLR4/MyD88/NF-κB pathway. Importantly, CAF decreases miR-301b expression through negative regulation of the cAMP/PKA/NF-κB axis. Further, c-Myb is identified as a target of miR-301b, which positively modulates anti-inflammatory cytokines IL-4 and TGF-β1, but negatively regulates pro-inflammatory cytokines MIP-1α and IL-17A. Moreover, repression of miR-301b results in increased transcription of c-Myb and elevated levels of neutrophil infiltration, thereby alleviating infectiou symptoms in mice. These findings reveal miR-301b as a new controller of inflammatory response by repressing c-Myb function to inhibit anti-inflammatory response to bacterial infection, representing a novel mechanism for balancing inflammation.
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Affiliation(s)
- Xuefeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Sisi He
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Rongpeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Xikun Zhou
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Shuang Zhang
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA.,State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Min Yu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA.,Department of Thoracic Oncology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yan Ye
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Yongsheng Wang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Canhua Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
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He S, Li X, Li R, Fang L, Sun L, Wang Y, Wu M. Annexin A2 Modulates ROS and Impacts Inflammatory Response via IL-17 Signaling in Polymicrobial Sepsis Mice. PLoS Pathog 2016; 12:e1005743. [PMID: 27389701 PMCID: PMC4936746 DOI: 10.1371/journal.ppat.1005743] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/14/2016] [Indexed: 02/05/2023] Open
Abstract
Sepsis is a progressive disease manifesting excessive inflammatory responses, severe tissue injury, organ dysfunction, and, ultimately, mortality. Since currently, there are limited therapeutic options for this disease, further understanding the molecular pathogenesis of sepsis may help develop effective treatments. Here we identify a novel role for Annexin A2 (AnxA2), a multi-compartmental protein, in inhibiting pro-inflammatory response by regulating reactive oxygen species (ROS) and IL-17 signaling during sepsis. In cecal ligation and puncture (CLP) sepsis models, anxa2-/- mice manifested increased pro-inflammatory cytokines and neutrophil infiltration, but decreased bacterial clearance and animal survival. In addition, AnxA2 deficiency led to intensified ROS and IL-17A. Using site directed mutagenesis, we uncovered that cysteine 9 of AnxA2 was the most important aa (site) for regulation of ROS levels. Furthermore, ROS appears to be responsible for elevated IL-17A levels and subsequently exaggerated inflammatory response. Depletion of IL-17 via CRISPR/Cas9 KO strategy down-regulated inflammation and conferred protection against sepsis in anxa2-/- mice. Our findings reveal a previously undemonstrated function for AnxA2 in inflammatory response in polymicrobial sepsis models via an AnxA2-ROS-IL-17 axis, providing insight into the regulation of pathophysiology of sepsis.
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Affiliation(s)
- Sisi He
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, P. R. China
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Xuefeng Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, P. R. China
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Rongpeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Lizhu Fang
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Lingyun Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, P. R. China
| | - Yongsheng Wang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, P. R. China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
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Li X, Ye Y, Zhou X, Huang C, Wu M. Atg7 enhances host defense against infection via downregulation of superoxide but upregulation of nitric oxide. THE JOURNAL OF IMMUNOLOGY 2014; 194:1112-21. [PMID: 25535282 DOI: 10.4049/jimmunol.1401958] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic bacterium that can cause serious infection in immunocompromised individuals. Although autophagy may augment immune responses against P. aeruginosa infection in macrophages, the critical components and their role of autophagy in host defense are largely unknown. In this study, we show that P. aeruginosa infection-induced autophagy activates JAK2/STAT1α and increases NO production. Knocking down Atg7 resulted in increased IFN-γ release, excessive reactive oxygen species, and increased Src homology-2 domain-containing phosphatase 2 activity, which led to lowered phosphorylation of JAK2/STAT1α and subdued expression of NO synthase 2 (NOS2). In addition, we demonstrated the physiological relevance of dysregulated NO under Atg7 deficiency as atg7(-/-) mice were more susceptible to P. aeruginosa infection with increased mortality and severe lung injury than wild-type mice. Furthermore, P. aeruginosa-infected atg7(-/-) mice exhibited increased oxidation but decreased bacterial clearance in the lung and other organs compared with wild-type mice. Mechanistically, atg7 deficiency suppressed NOS2 activity by downmodulating JAK2/STAT1α, leading to decreased NO both in vitro and in vivo. Taken together, these findings revealed that the JAK2/STAT1α/NOS2 dysfunction leads to dysregulated immune responses and worsened disease phenotypes.
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Affiliation(s)
- Xuefeng Li
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203; and State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Yan Ye
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203; and
| | - Xikun Zhou
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203; and State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Canhua Huang
- State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Min Wu
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203; and
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Li Y, Gan CP, Zhang S, Zhou XK, Li XF, Wei YQ, Yang JL, Wu M. FIP200 is involved in murine pseudomonas infection by regulating HMGB1 intracellular translocation. Cell Physiol Biochem 2014; 33:1733-44. [PMID: 24923305 PMCID: PMC4393741 DOI: 10.1159/000362954] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2014] [Indexed: 02/05/2023] Open
Abstract
Background FIP200, a critical autophagy initiating protein, can participate in numerous cellular functions including cancer development; however, its functional role in P. aeruginosa infection of alveolar macrophages is unknown. Methods To investigate the role of FIP200 in host defense, we transfected murine alveolar macrophage MH-S cells with FIP200 siRNA. Having confirmed that FIP200 knockdown inhibited PAO1-induced autophagosme formation, we sought to characterize the underlying signaling pathways by immunoblotting. Further, we used fip200 KO mice to study the effects of fip200 deficiency on HMGB1 translocation. Results We showed that Pseudomonas PAO1 strain infection facilitated autophagosome formation, whereas knockdown of FIP200 inhibited autophagosome formation and HMGB1 expression in MH-S cells. Silencing FIP200 impaired the translocation of HMGB1 to cytosol of MH-S cells and almost abolished acetylation of HMGB1 during PAO1 infection. In contrast, FIP200 overexpression facilitated the cytosol translocation of HMGB1 from nuclei and increased acetylation of HMGB1 in PAO1-infected MH-S cells. Importantly, expression and acetylation of HMGB1 were also significantly down-regulated in fip200 KO mice following PAO1 infection. Conclusions Collectively, these findings elucidate that FIP200 may regulate expression and translocation of HMGB1 during PAO1 infection, which may indicate novel therapeutic targets to control pulmonary infection.
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Affiliation(s)
- Yi Li
- State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
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Okoturo-Evans O, Dybowska A, Valsami-Jones E, Cupitt J, Gierula M, Boobis AR, Edwards RJ. Elucidation of toxicity pathways in lung epithelial cells induced by silicon dioxide nanoparticles. PLoS One 2013; 8:e72363. [PMID: 24023737 PMCID: PMC3762866 DOI: 10.1371/journal.pone.0072363] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/16/2013] [Indexed: 12/21/2022] Open
Abstract
A study into the effects of amorphous nano-SiO2 particles on A549 lung epithelial cells was undertaken using proteomics to understand the interactions that occur and the biological consequences of exposure of lung to nanoparticles. Suitable conditions for treatment, where A549 cells remained viable for the exposure period, were established by following changes in cell morphology, flow cytometry, and MTT reduction. Label-free proteomics was used to estimate the relative level of proteins from their component tryptic peptides detected by mass spectrometry. It was found that A549 cells tolerated treatment with 100 µg/ml nano-SiO2 in the presence of 1.25% serum for at least 4 h. After this time detrimental changes in cell morphology, flow cytometry, and MTT reduction were evident. Proteomics performed after 4 h indicated changes in the expression of 47 proteins. Most of the proteins affected fell into four functional groups, indicating that the most prominent cellular changes were those that affected apoptosis regulation (e.g. UCP2 and calpain-12), structural reorganisation and regulation of actin cytoskeleton (e.g. PHACTR1), the unfolded protein response (e.g. HSP 90), and proteins involved in protein synthesis (e.g. ribosomal proteins). Treatment with just 10 µg/ml nano-SiO2 particles in serum-free medium resulted in a rapid deterioration of the cells and in medium containing 10% serum the cells were resistant to up to 1000 µg/ml nano-SiO2 particles, suggesting interaction of serum components with the nanoparticles. A variety of serum proteins were found which bound to nano-SiO2 particles, the most prominent of which were albumin, apolipoprotein A-I, hemoglobin, vitronectin and fibronectin. The use of a proteomics platform, with appropriately designed experimental conditions, enabled the early biological perturbations induced by nano-SiO2 in a model target cell system to be identified. The approach facilitates the design of more focused test systems for use in tiered evaluations of nanomaterials.
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Affiliation(s)
- Odu Okoturo-Evans
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Agnieszka Dybowska
- Earth Sciences Department, Natural History Museum, London, United Kingdom
| | - Eugenia Valsami-Jones
- Earth Sciences Department, Natural History Museum, London, United Kingdom
- Geosystems Nanoscience, School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - John Cupitt
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Magdalena Gierula
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Alan R. Boobis
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Robert J. Edwards
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
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Srivastava A, Yadav S, Sharma A, Dwivedi UN, Flora SJS, Parmar D. Similarities in diesel exhaust particles induced alterations in expression of cytochrome P-450 and glutathione S-transferases in rat lymphocytes and lungs. Xenobiotica 2012; 42:624-32. [PMID: 22352393 DOI: 10.3109/00498254.2011.650732] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Freshly prepared peripheral blood lymphocytes (PBL) are known to express cytochrome P450s (CYPs) and glutathione S-transferases (GSTs) involved in the bioactivation and detoxification of organic components of diesel exhaust particles (DEPs). To validate that blood lymphocyte expression profiles could be used as a biomarker to predict exposure to vehicular emissions, similarities in the alterations in the mRNA expression of CYPs and GSTs were studied in PBL and lungs of rats exposed to DEPs. Adult male Wistar rats were treated transtracheally with different doses of DEPs (3.75- or 7.5- or 15- or 30-mg/kg b.wt.). The animals were anaesthetized after 24 h and blood was drawn and lungs were taken out and processed. DEP produced a similar pattern of increase in the mRNA expression of CYPs (CYP1A1, 1A2, 1B1, 2E1), associated arylhydrocarbon receptor (Ahr) and arylhydrocarbon nuclear translocator (Arnt) and GSTs (GSTPi, GSTM1 and GSTM2) at all the doses in lungs and PBL. The protein expression of CYP1A1/1A2 and 2E1 and catalytic activity of CYPs and GSTs also showed a similar pattern of increase in blood lymphocyte and in lungs isolated from DEP treated rats. Our data indicating similarities in the alterations in the expression of carcinogen metabolizing CYPs and GSTs in PBL with the lung enzymes suggests the suitability of using expression profiles of blood lymphocyte CYPs and GSTs as a biomarker to predict exposure to vehicular emissions.
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Affiliation(s)
- Ankita Srivastava
- Developmental Toxicology Division, Indian Institute of Toxicology Research (Council of Scientific & Industrial Research), M.G. Marg, Lucknow, Uttar Pradesh, India
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Yuan K, Huang C, Fox J, Gaid M, Weaver A, Li G, Singh BB, Gao H, Wu M. Elevated inflammatory response in caveolin-1-deficient mice with Pseudomonas aeruginosa infection is mediated by STAT3 protein and nuclear factor kappaB (NF-kappaB). J Biol Chem 2011; 286:21814-25. [PMID: 21515682 DOI: 10.1074/jbc.m111.237628] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Caveolin-1 (Cav-1), an important composition protein within the flask-shaped membrane invaginations termed caveolae, may play a role in host defense against infections. However, the phenotype in Pseudomonas aeruginosa-infected cav1 knock-out (KO) mice is still unresolved, and the mechanism involved is almost entirely unknown. Using a respiratory infection model, we confirmed a crucial role played by Cav-1 in host defense against this pathogen because Cav-1 KO mice showed increased mortality, severe lung injury, and systemic dissemination as compared with wild-type (WT) littermates. In addition, cav1 KO mice exhibited elevated inflammatory cytokines (IL-6, TNF-α, and IL-12a), decreased phagocytic ability of macrophages, and increased superoxide release in the lung, liver, and kidney. We further studied relevant cellular signaling processes and found that STAT3 and NF-κB are markedly activated. Our data revealed that the Cav-1/STAT3/NF-κB axis is responsible for a dysregulated cytokine response, which contributes to increased mortality and disease progression. Moreover, down-regulating Cav-1 in cell culture with a dominant negative strategy demonstrated that STAT3 activation was essential for the translocation of NF-κB into the nucleus, confirming the observations from cav1 KO mice. Collectively, our studies indicate that Cav-1 is critical for inflammatory responses regulating the STAT3/NF-κB pathway and thereby impacting P. aeruginosa infection.
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Affiliation(s)
- Kefei Yuan
- State Key Laboratory for Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
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Pasula R, Britigan BE, Turner J, Martin WJ. Airway delivery of silica increases susceptibility to mycobacterial infection in mice: potential role of repopulating macrophages. THE JOURNAL OF IMMUNOLOGY 2009; 182:7102-9. [PMID: 19454707 DOI: 10.4049/jimmunol.0803642] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Silica exposure results in an increased lifelong risk of developing mycobacterial pulmonary infections. To date, there are no animal models that replicate this finding to permit assessment of the mechanisms underlying susceptibility to mycobacterial infection. To test the hypothesis that prior silica exposure increases risk of mycobacterial infection, we intratracheally (I.T.) administered silica, a control dust (Al(2)O(3)) or saline into mechanically ventilated C57BL/6 mice. Later, the mice received Mycobacterium avium or Mycobacterium tuberculosis I.T. Mice were sacrificed at defined time points and mycobacteria in lung homogenates were quantified. M. avium or M. tuberculosis infection was markedly increased in silica-exposed mice compared with mice exposed to either Al(2)O(3) or saline beginning 3 wk after silica exposure. Similarly, lung sections from silica-exposed mice had many more acid fast bacilli(+) (AFB(+)) organisms than from control mice. Alveolar macrophages (AMs) from bronchoalveolar lavage of silica-exposed mice also revealed a higher number of mycobacteria compared with mice treated with Al(2)O(3) or saline. In addition, passive transfer of AMs from silica-exposed mice to control mice increased M. tuberculosis susceptibility. These results indicate that silica exposure converts mycobacteria-resistant mice into mycobacteria-susceptible mice via a process that likely involves a new population of AMs that are more susceptible to mycobacterial infection.
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Affiliation(s)
- Rajamouli Pasula
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA.
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11
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Kannan S, Huang H, Seeger D, Audet A, Chen Y, Huang C, Gao H, Li S, Wu M. Alveolar epithelial type II cells activate alveolar macrophages and mitigate P. Aeruginosa infection. PLoS One 2009; 4:e4891. [PMID: 19305493 PMCID: PMC2654511 DOI: 10.1371/journal.pone.0004891] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Accepted: 02/02/2009] [Indexed: 12/20/2022] Open
Abstract
Although alveolar epithelial type II cells (AECII) perform substantial roles in the maintenance of alveolar integrity, the extent of their contributions to immune defense is poorly understood. Here, we demonstrate that AECII activates alveolar macrophages (AM) functions, such as phagocytosis using a conditioned medium from AECII infected by P. aeruginosa. AECII-derived chemokine MCP-1, a monocyte chemoattractant protein, was identified as a main factor in enhancing AM function. We proposed that the enhanced immune potency of AECII may play a critical role in alleviation of bacterial propagation and pneumonia. The ability of phagocytosis and superoxide release by AM was reduced by MCP-1 neutralizing antibodies. Furthermore, MCP-1(-/-) mice showed an increased bacterial burden under PAO1 and PAK infection vs. wt littermates. AM from MCP-1(-/-) mice also demonstrated less superoxide and impaired phagocytosis over the controls. In addition, AECII conditioned medium increased the host defense of airway in MCP-1(-/-) mice through the activation of AM function. Mechanistically, we found that Lyn mediated NFkappaB activation led to increased gene expression and secretion of MCP-1. Consequently Lyn(-/-) mice had reduced MCP-1 secretion and resulted in a decrease in superoxide and phagocytosis by AM. Collectively, our data indicate that AECII may serve as an immune booster for fighting bacterial infections, particularly in severe immunocompromised conditions.
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Affiliation(s)
- Shibichakravarthy Kannan
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Huang Huang
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Drew Seeger
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Aaron Audet
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Yaoyu Chen
- Division of Hematology/Oncology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Canhua Huang
- State Key Laboratory for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Hongwei Gao
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Shaoguang Li
- Division of Hematology/Oncology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Min Wu
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
- State Key Laboratory for Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- * E-mail:
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Attik G, Brown R, Jackson P, Creutzenberg O, Aboukhamis I, Rihn BH. Internalization, Cytotoxicity, Apoptosis, and Tumor Necrosis Factor-α Expression in Rat Alveolar Macrophages Exposed to Various Dusts Occurring in the Ceramics Industry. Inhal Toxicol 2008; 20:1101-12. [DOI: 10.1080/08958370802136731] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Kannan S, Audet A, Huang H, Chen LJ, Wu M. Cholesterol-rich membrane rafts and Lyn are involved in phagocytosis during Pseudomonas aeruginosa infection. THE JOURNAL OF IMMUNOLOGY 2008; 180:2396-408. [PMID: 18250449 DOI: 10.4049/jimmunol.180.4.2396] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mechanism of phagocytosis of pathogens remains to be fully characterized. We report a novel phagocytosis pathway for Pseudomonas aeruginosa, which is initiated by cholesterol-rich membrane rafts and is dependent on Lyn, primarily an immune regulator with both positive and negative roles. Blocking of Lyn or blocking of cholesterol synthesis significantly inhibited phagocytosis by alveolar macrophages. We found that Lyn, via Src homology 2 and 3 domains, bound to and then activated PI3K and Akt to regulate intracellular routing of the engulfed P. aeruginosa. Further analysis indicates that Lyn and raft components entered in phagosomes and late lysosomes. Finally, respiratory burst was dependent on Lyn and membrane rafts, as confirmed by small interfering RNA and dominant-negative strategies. Our investigations demonstrate that Lyn along with membrane rafts plays a fundamental role in phagocytosis by alveolar macrophages during infection.
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Affiliation(s)
- Shibichakravarthy Kannan
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA
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Kottom TJ, Kennedy CC, Limper AH. Pneumocystis PCINT1, a molecule with integrin-like features that mediates organism adhesion to fibronectin. Mol Microbiol 2007; 67:747-61. [PMID: 18179594 DOI: 10.1111/j.1365-2958.2007.06093.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pneumocystis species cause severe pneumonia during chronic immunosuppression, especially in patients with AIDS or malignancy. Adhesion of Pneumocystis to extracellular matrix proteins, particularly fibronectin, associated with alveolar epithelial cell surfaces, triggers organism proliferative pathways. Herein, we report the characterization of a novel Pneumocystis molecule with considerable structural features of an integrin-like extracellular matrix adhesion receptor. A PCINT1115 bp probe was initially identified from partial sequence present within the Pneumocystis genome project database. A full-length 3018 bp cDNA was subsequently obtained with extensive homology to the C-terminal region of Candida albicans INT1 (31% blastx), a gene originally described as encoding an integrin-like molecule implicated in adhesion, growth, and virulence. Sequence analysis of PCINT1 indicated that the Pneumocystis molecule contained both a putative internal RGD motif and four Metal Ion-Dependent Attachment Sites (MIDAS) motifs required for coordination of divalent cations, as well as a specific tyrosine residue found in the cytoplasmic tails of some integrin receptors and C. albicans INT1. Northern, Western and immunofluorescence studies demonstrated that the trophic forms of Pneumocystis, known to be the life cycle forms that tightly adhere to lung epithelium, expressed the molecule to a substantially greater degree than cystic forms. Heterologous expression of PCINT1 in yeast followed by application to human fibronectin-coated surfaces demonstrated these yeast display PCINT1 on their surfaces and subsequently gain the ability to bind fibronectin in a cation dependent fashion. Taken together, these results indicate that Pneumocystis expresses a novel integrin-like PCINT1 molecule sufficient to mediate interactions with extracellular matrix fibronectin, an integral component of host-cell organism interactions during this infection.
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Affiliation(s)
- Theodore J Kottom
- Thoracic Diseases Research Unit, Division of Pulmonary, Critical Care and Internal Medicine, Rochester, MN 55905, USA
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Jin Y, Kannan S, Wu M, Zhao JX. Toxicity of luminescent silica nanoparticles to living cells. Chem Res Toxicol 2007; 20:1126-33. [PMID: 17630705 DOI: 10.1021/tx7001959] [Citation(s) in RCA: 226] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Luminescent nanomaterials can provide high-intensity and photostable luminescent signals when used as labeling materials for the determination of trace amounts of analytes. However, a major concern that has arisen is whether the nanomaterials cause toxic effects in living systems. Here, we address this problem through a systematic investigation of the cytotoxicity and genotoxicity of luminescent silica nanoparticles. These nanoparticles are intensely luminescent labeling materials for ultrasensitive determination of biological samples. The investigation of genotoxicity of the nanomaterials was carried out from two perspectives. First, the integrity of the DNA was examined by detecting DNA base modification, strand breaks, and increased DNA repair activity to recover the damage. Second, different sets of cellular DNAs, including nuclear DNA extracts and the whole genomic DNAs, were examined. Furthermore, to fully assess DNA damage by the nanoparticles, isolated genomic DNAs were directly exposed to the nanoparticles. The cytotoxicity of the nanoparticle was detected by measuring the cell proliferation rate, cell death, and death patterns (necrosis and apoptosis) after the nanoparticle treatments. Results show no significant toxic effects due to the luminescent nanoparticles at the molecular and cellular levels below a concentration of 0.1 mg/mL. Our study indicates that the luminescent silica nanoparticle is a promising labeling reagent for various biomedical applications.
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Affiliation(s)
- Yuhui Jin
- Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA
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Abstract
We have developed a simple method to dramatically improve Western blotting by use of water washing as well as altered buffer conditions. Our improved protocol reduces the cost and labor of Western blotting by shortening the washing time and uses less buffer and other reagents. This procedure does not significantly change existing protocols of Western blotting analysis; it simply contains a few modifications to the washing step and buffer conditions. Our improved technique may therefore have broad applications in various experimental conditions.
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Affiliation(s)
- Min Wu
- Division of Pulmonary, Allergy, Critical Care and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202-2879, USA
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Tobin MJ. Tuberculosis, lung infections, and interstitial lung disease in AJRCCM 2000. Am J Respir Crit Care Med 2001; 164:1774-88. [PMID: 11734425 DOI: 10.1164/ajrccm.164.10.2108127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
MESH Headings
- AIDS-Related Opportunistic Infections/diagnosis
- AIDS-Related Opportunistic Infections/epidemiology
- AIDS-Related Opportunistic Infections/immunology
- AIDS-Related Opportunistic Infections/therapy
- Animals
- Biomarkers/analysis
- Bronchiectasis/diagnosis
- Bronchiectasis/therapy
- Critical Care/methods
- Critical Care/standards
- Critical Care/trends
- Disease Models, Animal
- HIV Infections/complications
- HIV Infections/diagnosis
- HIV Infections/epidemiology
- HIV Infections/immunology
- HIV Infections/therapy
- Humans
- Hypertension, Pulmonary/diagnosis
- Hypertension, Pulmonary/therapy
- Immunocompromised Host
- Infections/diagnosis
- Infections/therapy
- Lung Diseases/diagnosis
- Lung Diseases/therapy
- Lung Diseases, Interstitial/diagnosis
- Lung Diseases, Interstitial/therapy
- Mass Screening/methods
- Molecular Biology
- Periodicals as Topic
- Risk Factors
- Sarcoidosis/diagnosis
- Sarcoidosis/genetics
- Sarcoidosis/therapy
- Scleroderma, Systemic/diagnosis
- Scleroderma, Systemic/therapy
- Tuberculosis, Pulmonary/diagnosis
- Tuberculosis, Pulmonary/epidemiology
- Tuberculosis, Pulmonary/therapy
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Affiliation(s)
- M J Tobin
- Division of Pulmonary and Critical Care Medicine, Loyola University of Chicago Stritch School of Medicine, Hines, Illinois 60141, USA.
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