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Saha S, Sachivkina N, Karamyan A, Novikova E, Chubenko T. Advances in Nrf2 Signaling Pathway by Targeted Nanostructured-Based Drug Delivery Systems. Biomedicines 2024; 12:403. [PMID: 38398005 PMCID: PMC10887079 DOI: 10.3390/biomedicines12020403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Nanotechnology has gained significant interest in various applications, including sensors and therapeutic agents for targeted disease sites. Several pathological consequences, including cancer, Alzheimer's disease, autoimmune diseases, and many others, are mostly driven by inflammation and Nrf2, and its negative regulator, the E3 ligase adaptor Kelch-like ECH-associated protein 1 (Keap1), plays a crucial role in maintaining redox status, the expression of antioxidant genes, and the inflammatory response. Interestingly, tuning the Nrf2/antioxidant response element (ARE) system can affect immune-metabolic mechanisms. Although many phytochemicals and synthetic drugs exhibited potential therapeutic activities, poor aqueous solubility, low bioavailability, poor tissue penetration, and, consequently, poor specific drug targeting, limit their practical use in clinical applications. Also, the therapeutic use of Nrf2 modulators is hampered in clinical applications by the absence of efficient formulation techniques. Therefore, we should explore the engineering of nanotechnology to modulate the inflammatory response via the Nrf2 signaling pathway. This review will initially examine the role of the Nrf2 signaling pathway in inflammation and oxidative stress-related pathologies. Subsequently, we will also review how custom-designed nanoscale materials encapsulating the Nrf2 activators can interact with biological systems and how this interaction can impact the Nrf2 signaling pathway and its potential outcomes, emphasizing inflammation.
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Affiliation(s)
- Sarmistha Saha
- Department of Biotechnology, Institute of Applied Sciences & Humanities, GLA University, Mathura 281406, India
| | - Nadezhda Sachivkina
- Department of Microbiology V.S. Kiktenko, Institute of Medicine, Peoples’ Friendship University of Russia (RUDN University), 117198 Moscow, Russia;
| | - Arfenya Karamyan
- Department of Veterinary Medicine, Agrarian Technological Institute, Peoples’ Friendship University of Russia (RUDN University), 117198 Moscow, Russia; (A.K.); (E.N.); (T.C.)
| | - Ekaterina Novikova
- Department of Veterinary Medicine, Agrarian Technological Institute, Peoples’ Friendship University of Russia (RUDN University), 117198 Moscow, Russia; (A.K.); (E.N.); (T.C.)
| | - Tamara Chubenko
- Department of Veterinary Medicine, Agrarian Technological Institute, Peoples’ Friendship University of Russia (RUDN University), 117198 Moscow, Russia; (A.K.); (E.N.); (T.C.)
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Kelley EF, Carlson AR, Wentz RJ, Ziegler BL, Johnson BD. Influence of rapidly oscillating inspired O 2 and N 2 concentrations on pulmonary vascular function and lung fluid balance in healthy adults. Front Physiol 2022; 13:1018057. [PMID: 36569769 PMCID: PMC9768664 DOI: 10.3389/fphys.2022.1018057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Introduction: Aircrew may experience rapidly oscillating inspired O2/N2 ratios owing to fluctuations in the on-board oxygen delivery systems (OBOG). Recent investigations suggest these oscillations may contribute to the constellation of physiologic events in aircrew of high-performance aircraft. Therefore, the purpose of this study was to determine whether these "operationally-relevant" environmental challenges may cause decrements in measures of pulmonary vascular physiology. Methods: Thirty healthy participants (Age: 29 ± 5 years) were recruited and assigned to one of the three exposures. Participants were instrumented for physiologic monitoring and underwent baseline cardiopulmonary physiology testing (ground level) consisting of a rebreathe method for quantifying pulmonary blood flow (Qc), pulmonary capillary blood volume (Vc) and alveolar-capillary conductance (Dm). Ultrasound was used to quantify "comet tails" (measure of lung fluid balance). After baseline testing, the participants had two 45 min exposures to an altitude of 8,000 ft where they breathed from gas mixtures alternating between 80/20 and 30/70 O2/N2 ratios at the required frequency (30 s, 60 s, or 120 s), separated by repeat baseline measure. Immediately and 45 min after the second exposure, baseline measures were repeated. Results: We observed no changes in Qc, Dm or Vc during the 60 s exposures. In response to the 30 s oscillation exposure, there was a significantly reduced Qc and Vc at the post-testing period (p = 0.03). Additionally, exposure to the 120 s oscillations resulted in a significant decrease in Vc at the recovery testing period and an increase in the Dm/Vc ratio at both the post and recovery period (p < 0.01). Additionally, we observed no changes in the number of comet tails. Conclusion: These data suggest "operationally-relevant" changes in inspired gas concentrations may cause an acute, albeit mild pulmonary vascular derecruitment, reduced distention and/or mild pulmonary-capillary vasoconstriction, without significant changes in lung fluid balance or respiratory gas exchange. The operational relevance remains less clear, particularly in the setting of additional environmental stressors common during flight (e.g., g forces).
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Affiliation(s)
- Eli F. Kelley
- AFRL, 711HPW, WPAFB, Dayton, OH, United States,*Correspondence: Eli F. Kelley,
| | - Alex R. Carlson
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States
| | - Robert J. Wentz
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States
| | - Briana L. Ziegler
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States
| | - Bruce D. Johnson
- Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, United States
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OGG1 in Lung—More than Base Excision Repair. Antioxidants (Basel) 2022; 11:antiox11050933. [PMID: 35624797 PMCID: PMC9138115 DOI: 10.3390/antiox11050933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 12/04/2022] Open
Abstract
As the organ executing gas exchange and directly facing the external environment, the lungs are challenged continuously by various stimuli, causing the disequilibration of redox homeostasis and leading to pulmonary diseases. The breakdown of oxidants/antioxidants system happens when the overproduction of free radicals results in an excess over the limitation of cleaning capability, which could lead to the oxidative modification of macromolecules including nucleic acids. The most common type of oxidative base, 8-oxoG, is considered the marker of DNA oxidative damage. The appearance of 8-oxoG could lead to base mismatch and its accumulation might end up as tumorigenesis. The base 8-oxoG was corrected by base excision repair initiated by 8-oxoguanine DNA glycosylase-1 (OGG1), which recognizes 8-oxoG from the genome and excises it from the DNA double strand, generating an AP site for further processing. Aside from its function in DNA damage repairment, it has been reported that OGG1 takes part in the regulation of gene expression, derived from its DNA binding characteristic, and showed impacts on inflammation. Researchers believe that OGG1 could be the potential therapy target for relative disease. This review intends to make an overall summary of the mechanism through which OGG1 regulates gene expression and the role of OGG1 in pulmonary diseases.
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Role of Human NADPH Quinone Oxidoreductase (NQO1) in Oxygen-Mediated Cellular Injury and Oxidative DNA Damage in Human Pulmonary Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5544600. [PMID: 34691356 PMCID: PMC8536466 DOI: 10.1155/2021/5544600] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 09/03/2021] [Indexed: 12/16/2022]
Abstract
Supplemental oxygen administration is frequently used in premature infants and adults with pulmonary insufficiency. NADPH quinone oxidoreductase (NQO1) protects cells from oxidative injury by decreasing reactive oxygen species (ROS). In this investigation, we tested the hypothesis that overexpression of NQO1 in BEAS-2B cells will mitigate cell injury and oxidative DNA damage caused by hyperoxia and that A-1221C single nucleotide polymorphism (SNP) in the NQO1 promoter would display altered susceptibility to hyperoxia-mediated toxicity. Using stable transfected BEAS-2B cells, we demonstrated that hyperoxia decreased cell viability in control cells (Ctr), but this effect was differentially mitigated in cells overexpressing NQO1 under the regulation of the CMV viral promoter, the wild-type NQO1 promoter (NQO1-NQO1), or the NQO1 promoter carrying the SNP. Interestingly, hyperoxia decreased the formation of bulky oxidative DNA adducts or 8-hydroxy-2′-deoxyguanosine (8-OHdG) in Ctr cells. qPCR studies showed that mRNA levels of CYP1A1 and NQO1 were inversely related to DNA adduct formation, suggesting the protective role of these enzymes against oxidative DNA injury. In SiRNA experiments entailing the NQO1-NQO1 promoter, hyperoxia caused decreased cell viability, and this effect was potentiated in cells treated with CYP1A1 siRNA. We also found that hyperoxia caused a marked induction of DNA repair genes DDB2 and XPC in Ctr cells, supporting the idea that hyperoxia in part caused attenuation of bulky oxidative DNA lesions by enhancing nucleotide excision repair (NER) pathways. In summary, our data support a protective role for human NQO1 against oxygen-mediated toxicity and oxidative DNA lesions in human pulmonary cells, and protection against toxicity was partially lost in SNP cells. Moreover, we also demonstrate a novel protective role for CYP1A1 in the attenuation of oxidative cells and DNA injury. Future studies on the mechanisms of attenuation of oxidative injury by NQO1 should help in developing novel approaches for the prevention/treatment of ARDS in humans.
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Chen Y, Zhang H, Li F, Wang X. Inhibition of CX3C receptor 1-mediated autophagy in macrophages alleviates pulmonary fibrosis in hyperoxic lung injury. Life Sci 2020; 259:118286. [PMID: 32810508 DOI: 10.1016/j.lfs.2020.118286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 08/04/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023]
Abstract
AIMS To investigate the role of CX3CR1 in hyperoxic lung injury induced pulmonary fibrosis. MATERIALS AND METHODS Hyperoxic lung injured mice were used as the disease model. Pulmonary fibrosis was determined by H&E and Masson's staining. Autophagy was investigated by western blot, immunofluorescence staining, and transmission electron microscopy. KEY FINDINGS We observed that increased CX3CR1 expression corresponded with increased pulmonary fibrosis. Additionally, silencing of CX3CR1 significantly alleviated the fibrosis when compared to the control. We observed that exposure of mouse to hyperoxic environment increased macrophage levels along with an increased CD11b expression in the lung tissues. Subsequently, we also observed an increased expression of LC3-II and decreased p62 expression in hyperoxic mice models, suggesting the potential role of hyperoxia induced autophagy. CD11b and LC3/CX3CR1 were expressed and co-localized in a manner indicating CX3CR1 indeed does regulate macrophage autophagy in the hyperoxic lung injury model. We observed a decrease in hyperoxia-associated fibrosis, along with a decrease in autophagy when we used 3-MA (autophagy inhibitor) in our hyperoxic lung injury model. To elucidate the pathway through which CX3CR1 regulated autophagy, we further analyzed the Akt1 pathway. Our experimental results indicated that the Akt1 inhibitor (A-674563) did significantly decrease macrophage autophagy and fibrosis in hyperoxic mice models. SIGNIFICANCE Thus, our data indicates a novel role of CX3CR1 in regulation of macrophage autophagy and promotion of pulmonary fibrosis in hyperoxic lung injured mice.
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Affiliation(s)
- Yuqing Chen
- Department of Respiratory, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai 200080, China.
| | - Hai Zhang
- Department of Respiratory, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai 200080, China
| | - Feng Li
- Department of Respiratory, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai 200080, China
| | - Xiaohui Wang
- Department of Clinical Pharmacology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai 200080, China
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Atha DH, Coskun E, Erdem O, Tona A, Reipa V, Nelson BC. Genotoxic Effects of Etoposide, Bleomycin, and Ethyl Methanesulfonate on Cultured CHO Cells: Analysis by GC-MS/MS and Comet Assay. J Nucleic Acids 2020; 2020:8810105. [PMID: 32802493 PMCID: PMC7414336 DOI: 10.1155/2020/8810105] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/13/2020] [Accepted: 07/07/2020] [Indexed: 01/13/2023] Open
Abstract
To evaluate methods for analysis of genotoxic effects on mammalian cell lines, we tested the effect of three common genotoxic agents on Chinese hamster ovary (CHO) cells by single-cell gel electrophoresis (comet assay) and gas chromatography-tandem mass spectrometry (GC-MS/MS). Suspension-grown CHO cells were separately incubated with etoposide, bleomycin, and ethyl methanesulfonate and analyzed by an alkaline comet assay and GC-MS/MS. Although DNA strand breaks were detected by the comet assay after treatment with all three agents, GC-MS/MS could only detect DNA nucleobase lesions oxidatively induced by bleomycin. This demonstrates that although GC-MS/MS has limitations in detection of genotoxic effects, it can be used for selected chemical genotoxins that contribute to oxidizing processes. The comet assay, used in combination with GC-MS/MS, can be a more useful approach to screen a wide range of chemical genotoxins as well as to monitor other DNA-damaging factors.
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Affiliation(s)
- Donald H. Atha
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA
| | - Erdem Coskun
- National Institute of Standards and Technology, Biomolecular Measurement Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA
- University of Maryland, Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA
| | - Onur Erdem
- National Institute of Standards and Technology, Biomolecular Measurement Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA
- University of Health Sciences Turkey, Department of Pharmaceutical Toxicology, Gulhane Faculty of Pharmacy, 06010 Ankara, Turkey
| | - Alessandro Tona
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA
| | - Vytas Reipa
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA
| | - Bryant C. Nelson
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Materials Measurement Laboratory, Gaithersburg, MD 20899, USA
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Xing Y, Liu X, Pu Q, Wu M, Zhao JX. Biocompatible G-Quadruplex/Hemin for Enhancing Antibacterial Activity of H2O2. ACS APPLIED BIO MATERIALS 2018; 1:1019-1027. [DOI: 10.1021/acsabm.8b00211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yuqian Xing
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Xiao Liu
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Qinqin Pu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Julia Xiaojun Zhao
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
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8
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Milena D, Elzbieta P. Determination of DNA Damage in the Retina Photoreceptors of Drosophila. Bio Protoc 2018; 8:e2708. [PMID: 34179251 DOI: 10.21769/bioprotoc.2708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/09/2018] [Accepted: 01/14/2018] [Indexed: 11/02/2022] Open
Abstract
The retina is sensitive for light damages, because of direct light exposure, especially intense blue and UV light, which increase level of ROS and other toxic phototransduction products in photoreceptor cells. In our previous work ( Damulewicz et al., 2017a and 2017b), we used 8-oxo-deoxyguanosine (8-OHdG) as a marker for oxidative stress to investigate the role of heme oxygenase in DNA protection against UV light. In this protocol, we showed how to determine the level of DNA damages in the retina using immunohistochemical staining.
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Affiliation(s)
- Damulewicz Milena
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Pyza Elzbieta
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
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Resseguie EA, Brookes PS, O’Reilly MA. SMG-1 kinase attenuates mitochondrial ROS production but not cell respiration deficits during hyperoxia. Exp Lung Res 2017; 43:229-239. [PMID: 28749708 PMCID: PMC5956894 DOI: 10.1080/01902148.2017.1339143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/02/2017] [Indexed: 12/29/2022]
Abstract
PURPOSE Supplemental oxygen (hyperoxia) used to treat individuals in respiratory distress causes cell injury by enhancing the production of toxic reactive oxygen species (ROS) and inhibiting mitochondrial respiration. The suppressor of morphogenesis of genitalia (SMG-1) kinase is activated during hyperoxia and promotes cell survival by phosphorylating the tumor suppressor p53 on serine 15. Here, we investigate whether SMG-1 and p53 blunt this vicious cycle of progressive ROS production and decline in mitochondrial respiration seen during hyperoxia. MATERIALS AND METHODS Human lung adenocarcinoma A549 and H1299 or colon carcinoma HCT116 cells were depleted of SMG-1, UPF-1, or p53 using RNA interference, and then exposed to room air (21% oxygen) or hyperoxia (95% oxygen). Immunoblotting was used to evaluate protein expression; a Seahorse Bioanalyzer was used to assess cellular respiration; and flow cytometry was used to evaluate fluorescence intensity of cells stained with mitochondrial or redox sensitive dyes. RESULTS Hyperoxia increased mitochondrial and cytoplasmic ROS and suppressed mitochondrial respiration without changing mitochondrial mass or membrane potential. Depletion of SMG-1 or its cofactor, UPF1, significantly enhanced hyperoxia-induced mitochondrial but not cytosolic ROS abundance. They did not affect mitochondrial mass, membrane potential, or hyperoxia-induced deficits in mitochondrial respiration. Genetic depletion of p53 in A549 cells and ablation of the p53 gene in H1299 or HCT116 cells revealed that SMG-1 influences mitochondrial ROS through activation of p53. CONCLUSIONS Our findings show that hyperoxia does not promote a vicious cycle of progressive mitochondrial ROS and dysfunction because SMG-1-p53 signaling attenuates production of mitochondrial ROS without preserving respiration. This suggests antioxidant therapies that blunt ROS production during hyperoxia may not suffice to restore cellular respiration.
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Affiliation(s)
- Emily A. Resseguie
- Department of Environmental Medicine, The University of Rochester, Rochester, New York, USA
| | - Paul S. Brookes
- Department of Anesthesiology, The University of Rochester, Rochester, New York, USA
| | - Michael A. O’Reilly
- Department of Environmental Medicine, The University of Rochester, Rochester, New York, USA
- Department of Pediatrics, The University of Rochester, Rochester, New York, USA
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10
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Ye Y, Lin P, Zhang W, Tan S, Zhou X, Li R, Pu Q, Koff JL, Dhasarathy A, Ma F, Deng X, Jiang J, Wu M. Response to Comment on "DNA Repair Interacts with Autophagy To Regulate Inflammatory Responses to Pulmonary Hyperoxia". THE JOURNAL OF IMMUNOLOGY 2017; 199:381-382. [PMID: 28696327 DOI: 10.4049/jimmunol.1700676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Yan Ye
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Ping Lin
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203.,State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing 400042, People's Republic of China
| | - Weidong Zhang
- 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
| | - Xikun Zhou
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203.,State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, People's Republic of China
| | - 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
| | - Qinqin Pu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Jonathan L Koff
- Department of Medicine, Yale University, New Haven, CT 06510
| | - Archana Dhasarathy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Feng Ma
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 100005, People's Republic of China; and
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Jianxin Jiang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing 400042, People's Republic of China;
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203;
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Wu X, Tan S, Xing Y, Pu Q, Wu M, Zhao JX. Graphene oxide as an efficient antimicrobial nanomaterial for eradicating multi-drug resistant bacteria in vitro and in vivo. Colloids Surf B Biointerfaces 2017; 157:1-9. [PMID: 28554055 DOI: 10.1016/j.colsurfb.2017.05.024] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/05/2017] [Accepted: 05/10/2017] [Indexed: 12/20/2022]
Abstract
Graphene is a novel two-dimensional nanomaterial with a growing number of practical applications across numerous fields. In this work, we explored potential biomedical applications of graphene oxide (GO) by systematically studying antibacterial capacity of GO in both macrophages and animal models. Three types of bacteria, including Klebsiella pneumoniae (Kp), Escherichia coli (E. coli) and P. aeruginosa (Pa) were used for in vitro study. Kp was also selected as a representative multidrug resistant (MDR) bacterium for in vivo study. In in vitro study, GO effectively eradicated Kp in agar dishes and thus protected alveolar macrophages (AM) from Kp infection in the culture. In the in vivo evaluation, GO were introduced intranasally into mouse lungs followed by testing organ tissue damage including lung, liver, spleen, and kidneys, polymorphonuclear neutrophil (PMN) penetration, bacterial dissemination, and mortality in Kp-infected mice. We found that GO can prohibit the growth and spread of Kp both in vitro and in vivo, resulting in significantly increased cell survival rate, less tissue injury, subdued inflammatory response, and prolonged mice survival. These findings indicate that GO could be a promising biomaterial for effectively controlling MDR pathogens.
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Affiliation(s)
- Xu Wu
- Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA
| | - Shirui Tan
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA; Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Yunnan University, Kunming 650091, China
| | - Yuqian Xing
- Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA
| | - Qinqin Pu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA.
| | - Julia Xiaojun Zhao
- Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA.
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Ye Y, Lin P, Zhang W, Tan S, Zhou X, Li R, Pu Q, Koff JL, Dhasarathy A, Ma F, Deng X, Jiang J, Wu M. DNA Repair Interacts with Autophagy To Regulate Inflammatory Responses to Pulmonary Hyperoxia. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2017; 198:2844-2853. [PMID: 28202616 PMCID: PMC5360514 DOI: 10.4049/jimmunol.1601001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 01/23/2017] [Indexed: 12/11/2022]
Abstract
Oxygen is supplied as a supportive treatment for patients suffering from acute respiratory distress syndrome. Unfortunately, high oxygen concentration increases reactive oxygen species generation, which causes DNA damage and ultimately cell death in the lung. Although 8-oxoguanine-DNA glycosylase (OGG-1) is involved in repairing hyperoxia-mediated DNA damage, the underlying molecular mechanism remains elusive. In this study, we report that ogg-1-deficient mice exhibited a significant increase of proinflammatory cytokines (TNF-α, IL-6, and IFN-γ) in the lung after being exposed to 95% oxygen. In addition, we found that ogg-1 deficiency downregulated (macro)autophagy when exposed to hyperoxia both in vitro and in vivo, which was evident by decreased conversion of LC3-I to LC3-II, reduced LC3 punctate staining, and lower Atg7 expression compared with controls. Using a chromatin immunoprecipitation assay, we found that OGG-1 associated with the promoter of Atg7, suggesting a role for OGG1 in regulation of Atg7 activity. Knocking down OGG-1 decreased the luciferase reporter activity of Atg7. Further, inflammatory cytokine levels in murine lung epithelial cell line cells were downregulated following autophagy induction by starvation and rapamycin treatment, and upregulated when autophagy was blocked using 3-methyladenine and chloroquine. atg7 knockout mice and Atg7 small interfering RNA-treated cells exhibited elevated levels of phospho-NF-κB and intensified inflammatory cytokines, suggesting that Atg7 impacts inflammatory responses to hyperoxia. These findings demonstrate that OGG-1 negatively regulates inflammatory cytokine release by coordinating molecular interaction with the autophagic pathway in hyperoxia-induced lung injury.
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Affiliation(s)
- Yan Ye
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Ping Lin
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing 400042, People's Republic of China
| | - Weidong Zhang
- 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
| | - Xikun Zhou
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
- State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, People's Republic of China
| | - 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 2211116, People's Republic of China
| | - Qinqin Pu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Jonathan L Koff
- Department of Medicine, Yale University, New Haven, CT 06510
| | - Archana Dhasarathy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Feng Ma
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 100005, People's Republic of China; and
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Jianxin Jiang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, The Third Military Medical University, Chongqing 400042, People's Republic of China;
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203;
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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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Zhang W, Li Y, Ding H, Du Y, Wang L. Hydrogen peroxide prevents vascular calcification induced ROS production by regulating Nrf-2 pathway. Ren Fail 2016; 38:1099-106. [PMID: 27300444 DOI: 10.1080/0886022x.2016.1194143] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Although vascular calcification in end-stage renal disease (ESRD) represents a ubiquitous human health problem, effective therapies with limited side effects are still lacking, and the precise mechanisms are not fully understood. The Nrf-2/ARE pathway is a pivotal to regulate anti-oxidative responses in vascular calcification upon ESRD. Although Nrf-2 plays a crucial role in atherosclerosis, pulmonary fibrosis, and brain ischemia, the effect of Nrf-2 and oxidative stress on vascular calcification in ESRD patients is still unclear. The aim of this research was to study the protective role of hydrogen peroxide in vascular calcification and the mechanism of Nrf-2 and oxidative stress on vascular calcification. MATERIALS AND METHODS Here we used the rat vascular smooth muscle cell model of β-glycerophosphate-induced calcification resembling vascular calcification in ESRD to investigate the therapeutic effect of 0.01 mM hydrogen peroxide on vascular calcification and further explores the possible underlying mechanisms. RESULTS Our current report shows the in vitro role of 0.01 mM hydrogen peroxide in protecting against intracellular ROS accumulation upon vascular calcification. Both hydrogen peroxide and sulforaphane pretreatment reduced ROS production, increased the expression of Nrf-2, and decreased the expression of Runx2 following calcification. CONCLUSION Our study demonstrates that 0.01 mM hydrogen peroxide can effectively protect rat aortic vascular smooth muscle cells against oxidative stress by preventing vascular calcification induced ROS production through Nrf-2 pathway. These data might define an antioxidant role of hydrogen peroxide in vascular calcification upon ESRD.
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Affiliation(s)
- Wensong Zhang
- a Department of Nephrology , University of Electronic Science and Technology, Sichuan Academy of Sciences & Sichuan Provincial People's Hospital , Chengdu , China
| | - Yi Li
- a Department of Nephrology , University of Electronic Science and Technology, Sichuan Academy of Sciences & Sichuan Provincial People's Hospital , Chengdu , China
| | - Hanlu Ding
- a Department of Nephrology , University of Electronic Science and Technology, Sichuan Academy of Sciences & Sichuan Provincial People's Hospital , Chengdu , China
| | - Yaqin Du
- a Department of Nephrology , University of Electronic Science and Technology, Sichuan Academy of Sciences & Sichuan Provincial People's Hospital , Chengdu , China
| | - Li Wang
- a Department of Nephrology , University of Electronic Science and Technology, Sichuan Academy of Sciences & Sichuan Provincial People's Hospital , Chengdu , China
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15
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Zhuang Y, Li Y, Li X, Xie Q, Wu M. Atg7 Knockdown Augments Concanavalin A-Induced Acute Hepatitis through an ROS-Mediated p38/MAPK Pathway. PLoS One 2016; 11:e0149754. [PMID: 26939081 PMCID: PMC4777387 DOI: 10.1371/journal.pone.0149754] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/04/2016] [Indexed: 02/02/2023] Open
Abstract
Concanavalin A (ConA), a T-cell mitogen that induces acute autoimmune hepatitis, is widely used to model pathophysiological processes of human acute autoimmune liver disease. Although autophagy has been extensively studied in the past decade, little is known about its molecular mechanism underlying the regulation of ConA-induced acute hepatitis. In this study, we used a Cre-conditional atg7 KO mouse to investigate the effects of Atg7-associated autophagy on ConA-induced murine hepatitis. Our results demonstrated that atg7 deficiency in mice enhanced macrophage activation and increased pro-inflammatory cytokines upon ConA stimulation. Atg7 silencing resulted in accumulation of dysfunctional mitochondria, disruption of reactive oxygen species (ROS) degradation, and increase in pro-inflammatory cytokines in Raw264.7 cells. p38/MAPK and NF-κB levels were increased upon ConA induction due to Atg7 deficiency. Blocking ROS production inhibited ConA-induced p38/IκB phosphorylation and subsequent intracellular inflammatory responses. Hence, this study demonstrated that atg7 knockout in mice or Atg7 knockdown in cell culture augmented ConA-induced acute hepatitis and related cellular malfunction, indicating protective effects of Atg7 on regulating mitochondrial ROS via a p38/MAPK-mediated pathway. Collectively, our findings reveal that autophagy may attenuate macrophage-mediated inflammatory response to ConA and may be the potential therapeutic targets for acute liver injury.
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Affiliation(s)
- Yan Zhuang
- Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin Road II, Shanghai 200025, China
- Department of Basic Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Yi Li
- Department of Basic Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Xuefeng Li
- Department of Basic Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Qing Xie
- Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin Road II, Shanghai 200025, China
| | - Min Wu
- Department of Basic Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
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16
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Porzionato A, Sfriso MM, Mazzatenta A, Macchi V, De Caro R, Di Giulio C. Effects of hyperoxic exposure on signal transduction pathways in the lung. Respir Physiol Neurobiol 2015; 209:106-14. [DOI: 10.1016/j.resp.2014.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 12/18/2022]
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17
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Jin L, Yang H, Fu J, Xue X, Yao L, Qiao L. Association between oxidative DNA damage and the expression of 8-oxoguanine DNA glycosylase 1 in lung epithelial cells of neonatal rats exposed to hyperoxia. Mol Med Rep 2015; 11:4079-86. [PMID: 25672835 PMCID: PMC4394948 DOI: 10.3892/mmr.2015.3339] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 12/17/2014] [Indexed: 11/06/2022] Open
Abstract
Previous studies have demonstrated that oxidative stress‑induced lung injury is involved in the occurrence and developmental process of bronchopulmonary dysplasia (BPD). The present study assessed whether oxidative DNA damage occurs in the early stages of hyperoxia‑induced BPD in neonatal rats and evaluated the expression and localization of the DNA repair gene, 8‑oxoguanine DNA glycosylase 1 (OGG1), upon exposure to hyperoxia. Neonatal rats and primary cultured neonatal rat alveolar epithelial type II (AECII) cells were exposed to hyperoxia (90% O2) or normoxia (21% O2) and the expression levels of 8‑hydroxy‑2'‑deoxyguanosine (8‑OHdG) in the lung tissues and AECII cells were determined using a competitive enzyme‑linked immunosorbent assay. DNA strand breaks in the AECII cells were detected using a comet assay. The expression and localization of the OGG1 protein in the lung tissues and AECII cells were determined by immunofluorescence confocal microscopy and western blotting. The mRNA expression levels of OGG1 in the lung tissues and AECII cells were determined by reverse transcription polymerase chain reaction. The expression of 8‑OHdG was elevated in the hyperoxia‑exposed neonatal rat lung tissue and the AECII cells compared with the normoxic controls. The occurrence of DNA strand breaks in the AECII cells increased with increasing duration of hyperoxia exposure. The protein expression of OGG1 was significantly increased in the hyperoxia‑exposed lung tissues and AECII cells, with OGG1 preferentially localized to the cytoplasm. No concomitant increase in the mRNA expression of OGG1 was detected. These results revealed that oxidative DNA damage occurred in lung epithelial cells during early‑stage BPD, as confirmed by in vitro and in vivo hyperoxia exposure experiments, and the increased expression of OGG1 was associated with this process.
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Affiliation(s)
- Linlin Jin
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Haiping Yang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Jianhua Fu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Xindong Xue
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Li Yao
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Lin Qiao
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
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18
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Tan S, Gan C, Li R, Ye Y, Zhang S, Wu X, Yang YY, Fan W, Wu M. A novel chemosynthetic peptide with β-sheet motif efficiently kills Klebsiella pneumoniae in a mouse model. Int J Nanomedicine 2015; 10:1045-59. [PMID: 25709431 PMCID: PMC4330034 DOI: 10.2147/ijn.s73303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Klebsiella pneumoniae (Kp) is one of the most common pathogens in nosocomial infections and is increasingly becoming multiple drug resistant. However, the molecular pathogenesis of Kp in causing tissue injury and dysregulated host defense remains elusive, further dampening the development of novel therapeutic measures. We have previously screened a series of synthetic antimicrobial beta-sheet forming peptides and identified a peptide (IRIKIRIK; ie, IK8L) with a broad range of bactericidal activity and low cytotoxicity in vitro. Here, employing an animal model, we investigated the antibacterial effects of IK8L in acute infection and demonstrated that peritoneal injection of IK8L to mice down-regulated inflammatory cytokines, alleviated lung injury, and importantly, decreased mortality compared to sham-injected controls. In addition, a math model was used to evaluate in vivo imaging data and predict infection progression in infected live animals. Mechanistically, IK8L can kill Kp by inhibiting biofilm formation and modulating production of inflammatory cytokines through the STAT3/JAK signaling both in vitro and in vivo. Collectively, these findings reveal that IK8L may have potential for preventing or treating Kp infection.
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Affiliation(s)
- Shirui Tan
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA ; Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Yunnan University, Kunming, People's Republic of China
| | - Changpei Gan
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA ; State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Rongpeng Li
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA
| | - Yan Ye
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA
| | - Shuang Zhang
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA ; State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, People's Republic of China
| | - Xu Wu
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA
| | - Yi Yan Yang
- Institute of Bioengineering and Nanotechnology, The Nanos, Singapore
| | - Weimin Fan
- Program of Innovative Cancer Therapeutics, First Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of China
| | - Min Wu
- Department of Basic Sciences, School of Medicine and Health Sciences University of North Dakota, Grand Forks, ND, USA
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Chen J, Li X, Wu X, Pierce J, Fahruddin N, Wu M, Zhao JX. Au-Silica nanowire nanohybrid as a hyperthermia agent for photothermal therapy in the near-infrared region. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9514-23. [PMID: 25029292 PMCID: PMC4132849 DOI: 10.1021/la5020434] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 07/13/2014] [Indexed: 05/29/2023]
Abstract
Nanomaterial-based photothermal therapy has shown great potential for efficient cancer treatment. Here, we report a new hyperthermia agent, Au-silica nanowire nanohybrid (Au-SiNW nanohybrid) with tunable optical properties, for photothermal therapy. The unique feature of the synthetic method is no need of surface modification of SiNWs for the direct deposition of Au seeds, which can avoid complicated synthetic procedures and improve the reproducibility. The Au-SiNW nanohybrid can generate significant amount of heat upon irradiation in the near-infrared (NIR) region for inducing thermal cell death. Moreover, compared to reported hyperthermia nanomaterials, the new nanohybrid requires a much lower laser irradiation density of 0.3 W/cm(2) for destroying cancer cells. A549 lung cancer cells were used for in vitro photothermal study. The nanohybrid showed excellent in vitro biocompatibility by using a 96-nonradioactive-cell proliferation assay. Even at a high concentration of 0.500 mg/mL nanohybrid, over 80% cells were alive. In contrast, almost all the cells were killed when NIR irradiation was applied at a concentration of 0.100 mg/mL nanohybrid. The Au-SiNW nanohybrid may become a promising hyperthermia agent.
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Affiliation(s)
- Jiao Chen
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Xuefeng Li
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Xu Wu
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Joshua
T. Pierce
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Nenny Fahruddin
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Min Wu
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Julia Xiaojun Zhao
- Department of Chemistry and Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58202, United States
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20
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Zhao K, Li Y, Yue B, Wu M. Genes as early responders regulate quorum-sensing and control bacterial cooperation in Pseudomonas aeruginosa. PLoS One 2014; 9:e101887. [PMID: 25006971 PMCID: PMC4090235 DOI: 10.1371/journal.pone.0101887] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 06/12/2014] [Indexed: 11/19/2022] Open
Abstract
Quorum-sensing (QS) allows bacterial communication to coordinate the production of extracellular products essential for population fitness at higher cell densities. It has been generally accepted that a significant time duration is required to reach appropriate cell density to activate the relevant quiescent genes encoding these costly but beneficial public goods. Which regulatory genes are involved and how these genes control bacterial communication at the early phases are largely un-explored. By determining time-dependent expression of QS-related genes of the opportunistic pathogen Pseudomonas aerugionsa, we show that the induction of social cooperation could be critically influenced by environmental factors to optimize the density of population. In particular, small regulatory RNAs (RsmY and RsmZ) serving as early responders, can promote the expression of dependent genes (e.g. lasR) to boost the synthesis of intracellular enzymes and coordinate instant cooperative behavior in bacterial cells. These early responders, acting as a rheostat to finely modulate bacterial cooperation, which may be quickly activated under environment threats, but peter off when critical QS dependent genes are fully functional for cooperation. Our findings suggest that RsmY and RsmZ critically control the timing and levels of public goods production, which may have implications in sociomicrobiology and infection control.
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Affiliation(s)
- Kelei Zhao
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Yi Li
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Bisong Yue
- Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Min Wu
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
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21
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Ye Y, Li X, Wang W, Ouedraogo KC, Li Y, Gan C, Tan S, Zhou X, Wu M. Atg7 deficiency impairs host defense against Klebsiella pneumoniae by impacting bacterial clearance, survival and inflammatory responses in mice. Am J Physiol Lung Cell Mol Physiol 2014; 307:L355-63. [PMID: 24993132 DOI: 10.1152/ajplung.00046.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Klebsiella pneumoniae (Kp) is a Gram-negative bacterium that can cause serious infections in humans. Autophagy-related gene 7 (Atg7) has been implicated in certain bacterial infections; however, the role of Atg7 in macrophage-mediated immunity against Kp infection has not been elucidated. Here we showed that Atg7 expression was significantly increased in murine alveolar macrophages (MH-S) upon Kp infection, indicating that Atg7 participated in host defense. Knocking down Atg7 with small-interfering RNA increased bacterial burdens in MH-S cells. Using cell biology assays and whole animal imaging analysis, we found that compared with wild-type mice atg7 knockout (KO) mice exhibited increased susceptibility to Kp infection, with decreased survival rates, decreased bacterial clearance, and intensified lung injury. Moreover, Kp infection induced excessive proinflammatory cytokines and superoxide in the lung of atg7 KO mice. Similarly, silencing Atg7 in MH-S cells markedly increased expression levels of proinflammatory cytokines. Collectively, these findings reveal that Atg7 offers critical resistance to Kp infection by modulating both systemic and local production of proinflammatory cytokines.
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Affiliation(s)
- Yan Ye
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Xuefeng Li
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Wenxue Wang
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Kiswendsida Claude Ouedraogo
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Yi Li
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Changpei Gan
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Shirui Tan
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Xikun Zhou
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Min Wu
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota
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22
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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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23
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Li X, Zhou X, Li Y, Li J, Privratsky B, Ye Y, Wu E, Gao H, Huang C, Wu M. Lyn regulates inflammatory responses in Klebsiella pneumoniae infection via the p38/NF-κB pathway. Eur J Immunol 2014; 44:763-73. [PMID: 24338528 PMCID: PMC4103995 DOI: 10.1002/eji.201343972] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 10/07/2013] [Accepted: 11/11/2013] [Indexed: 02/05/2023]
Abstract
Klebsiella pneumoniae (Kp) is one of the most common pathogens in nosocomial infections and is becoming increasingly multidrug resistant. However, the underlying molecular pathogenesis of this bacterium remains elusive, limiting the therapeutic options. Understanding the mechanism of its pathogenesis may facilitate the development of anti-bacterial therapeutics. Here, we show that Lyn, a pleiotropic Src tyrosine kinase, is involved in host defense against Kp by regulating phagocytosis process and simultaneously downregulating inflammatory responses. Using acute infection mouse models, we observed that lyn(-/-) mice were more susceptible to Kp with increased mortality and severe lung injury compared with WT mice. Kp infected-lyn(-/-) mice exhibited elevated inflammatory cytokines (IL-6 and TNF-α), and increased superoxide in the lung and other organs. In addition, the phosphorylation of p38 and NF-κB p65 subunit increased markedly in response to Kp infection in lyn(-/-) mice. We also demonstrated that the translocation of p65 from cytoplasm to nuclei increased in cultured murine lung epithelial cells by Lyn siRNA knockdown. Furthermore, lipid rafts clustered with activated Lyn and accumulated in the site of Kp invasion. Taken together, these findings revealed that Lyn may participate in host defense against Kp infection through the negative modulation of inflammatory cytokines.
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Affiliation(s)
- Xuefeng Li
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, P. R. China
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Xikun Zhou
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, P. R. China
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Yi Li
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, P. R. China
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Jiaxin Li
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Breanna Privratsky
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Yan Ye
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
| | - Erxi Wu
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, USA
| | - Hongwei Gao
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative & Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Canhua Huang
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, P. R. China
| | - Min Wu
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203-9037, USA
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Chatterjee N, Eom HJ, Choi J. Effects of silver nanoparticles on oxidative DNA damage-repair as a function of p38 MAPK status: a comparative approach using human Jurkat T cells and the nematode Caenorhabditis elegans. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2014; 55:122-133. [PMID: 24347047 DOI: 10.1002/em.21844] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/19/2013] [Accepted: 12/01/2013] [Indexed: 06/03/2023]
Abstract
The large-scale use of silver nanoparticles (AgNPs) has raised concerns over potential impacts on the environment and human health. We previously reported that AgNP exposure causes an increase in reactive oxygen species, DNA damage, and induction of p38 MAPK and PMK-1 in Jurkat T cells and in Caenorhabditis elegans. To elucidate the underlying mechanisms of AgNP toxicity, here we evaluate the effects of AgNPs on oxidative DNA damage-repair (in human and C. elegans DNA glycosylases hOGG1, hNTH1, NTH-1, and 8-oxo-GTPases-hMTH1, NDX-4) and explore the role of p38 MAPK and PMK-1 in this process. Our comparative approach examined viability, gene expression, and enzyme activities in wild type (WT) and p38 MAPK knock-down (KD) Jurkat T cells (in vitro) and in WT and pmk-1 loss-of-function mutant strains of C. elegans (in vivo). The results suggest that p38 MAPK/PMK-1 plays protective role against AgNP-mediated toxicity, reduced viability and greater accumulation of 8OHdG was observed in AgNP-treated KD cells, and in pmk-1 mutant worms compared with their WT counterparts, respectively. Furthermore, dose-dependent alterations in hOGG1, hMTH1, and NDX-4 expression and enzyme activity, and survival in ndx-4 mutant worms occurred following AgNP exposure. Interestingly, the absence or depletion of p38 MAPK/PMK-1 caused impaired and additive effects in AgNP-induced ndx-4(ok1003); pmk-1(RNAi) mutant survival, and hOGG1 and NDX-4 expression and enzyme activity, which may lead to higher accumulation of 8OHdG. Together, the results indicate that p38 MAPK/PMK-1 plays an important protective role in AgNP-induced oxidative DNA damage-repair which is conserved from C. elegans to humans.
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Affiliation(s)
- Nivedita Chatterjee
- School of Environmental Engineering, Graduate School of Energy and Environmental system Engineering, University of Seoul, 163 Siripdaero, Dongdaemun-gu, Seoul, 130-743, Korea
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Zhao Y, Ye Y, Zhou X, Chen J, Jin Y, Hanson A, Zhao JX, Wu M. Photosensitive fluorescent dye contributes to phototoxicity and inflammatory responses of dye-doped silica NPs in cells and mice. Am J Cancer Res 2014; 4:445-59. [PMID: 24578727 PMCID: PMC3936296 DOI: 10.7150/thno.7653] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 01/27/2014] [Indexed: 11/18/2022] Open
Abstract
Dye-doped fluorescent silica nanoparticles provide highly intense and photostable fluorescence signals. However, some dopant dye molecules are photosensitive. A widely-used photosensitive fluorescent dopant, RuBpy, was chosen to systematically investigate the phototoxicity of the dye-doped silica nanoparticles (NPs). We investigated cell viability, DNA damage, and Reactive Oxygen Species (ROS) levels in alveolar macrophages using the dye-doped NPs with or without irradiation. Our results showed that the RuBpy-doped silica NPs could induce significant amount of ROS, DNA damage, apoptosis and impaired proliferation in MH-S cells. In vivo studies in mice showed that RuBpy-doped silica NPs induced significant inflammatory cytokine production and lowered expression in signaling proteins such as ERK1/2 and NF-κB as well as increased lung injury determined by myeloperoxidase and lipid peroxidation. Strikingly, we also found that both RuBpy alone and NPs induced systemic signaling activation in the kidney compared to the liver and lung where showed highly selective signaling patterns, which is more pronounced than RuBpy-doped silica NPs. Moreover, we discovered a critical biomarker (e.g., HMGB1) for silica NPs-induced stress and toxicity and demonstrated differentially-regulated response patterns in various organs. Our results indicate for the first time that the RuBpy-doped silica NPs may impose less inflammatory responses but stronger thermotherapeutic effects on target cells in animals than naked NPs in a time- and dose-dependent manner.
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Huang H, Weaver A, Wu E, Li Y, Gao H, Fan W, Wu M. Lipid-based signaling modulates DNA repair response and survival against Klebsiella pneumoniae infection in host cells and in mice. Am J Respir Cell Mol Biol 2013; 49:798-807. [PMID: 23742126 DOI: 10.1165/rcmb.2013-0069oc] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Klebsiella pneumoniae causes serious infections in the urinary tract, respiratory tract, and blood. Lipid rafts, also known as membrane microdomains, have been linked to the pathogenesis of bacterial infection. However, whether lipid rafts affect K. pneumoniae internalization into host cells remains unknown. Here, we show for the first time that K. pneumoniae was internalized into lung cells by activating lipid rafts. Disrupting lipid rafts by methyl-β-cyclodextrin inhibited pathogen internalization, impairing host defense. A deficient mutant of capsule polysaccharide (CPS) showed a higher internalization rate than a wild-type strain, indicating that CPS may inhibit bacterial entry to host cells. Furthermore, lipid rafts may affect the function of extracellular regulated kinase (ERK)-1/2, and knocking down ERK1/2 via short, interfering RNA increased apoptosis in both alveolar macrophages and epithelial cells after infection. To gain insights into bacterial pathogenesis, we evaluated the impact of lipid rafts on DNA integrity, and showed that raft aggregates also affect DNA damage and DNA repair responses (i.e., 8-oxoguanine DNA glycosylase [Ogg1]) through the regulation of reactive oxygen species. Importantly, cells overexpressing Ogg1 demonstrated reduced cytotoxicity during bacterial infection. Taken together, these results suggest that lipid rafts may modulate bacterial internalization, thereby affecting DNA damage and repair, which is critical to host defense against K. pneumoniae.
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Affiliation(s)
- Huang Huang
- 1 Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota
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Baicalein (5,6,7-trihydroxyflavone) reduces oxidative stress-induced DNA damage by upregulating the DNA repair system. Cell Biol Toxicol 2012; 28:421-33. [PMID: 23011636 DOI: 10.1007/s10565-012-9233-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Accepted: 09/16/2012] [Indexed: 10/27/2022]
Abstract
Oxidative stress caused by reactive oxygen species (ROS) induces DNA base modifications and DNA strand breaks. In this study, the protective effect of baicalein against H(2)O(2)-induced DNA damage was investigated in V79-4 Chinese hamster fibroblast cells. H(2)O(2) treatment increased the levels of intracellular ROS and DNA double-strand breaks (DSBs) and decreased the level of Ku70 protein and the phosphorylation (activation) of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), which are involved in the repair of DSBs by nonhomologous end joining. Baicalein effectively scavenged intracellular ROS induced by H(2)O(2), reduced DSBs, and rescued Ku70 protein level and phosphorylation of DNA-PKcs. In cellular response to DNA base damage, 8-oxoguanine DNA glycosylase 1 (OGG1) plays a vital role in the removal of 8-oxoguanine (8-OxoG), which is formed mainly by oxidative stress. Baicalein significantly decreased the levels of 8-OxoG induced by H(2)O(2), and this correlated with increases in OGG1 promoter activity and OGG1 mRNA and protein expression. The phosphorylated form of Akt kinase, which is a regulator of OGG1, was sharply decreased by H(2)O(2), but was prevented by baicalein. A specific Akt inhibitor abolished the cytoprotective effects of baicalein, suggesting that OGG1 induction by baicalein involves the Akt pathway. In conclusion, baicalein exerted protective effects against DNA damage induced by oxidative stress by activating DNA repair systems and scavenging ROS.
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Guo Q, Shen N, Yuan K, Li J, Wu H, Zeng Y, Fox J, Bansal AK, Singh BB, Gao H, Wu M. Caveolin-1 plays a critical role in host immunity against Klebsiella pneumoniae by regulating STAT5 and Akt activity. Eur J Immunol 2012; 42:1500-11. [PMID: 22678904 DOI: 10.1002/eji.201142051] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Caveolin-1 (Cav1) is a structural protein of caveolae. Although Cav1 is associated with certain bacterial infections, it is unknown whether Cav1 is involved in host immunity against Klebsiella pneumoniae, the third most commonly isolated microorganism from bacterial sepsis patients. Here, we showed that cav1 knockout mice succumbed to K. pneumoniae infection with markedly decreased survival rates, increased bacterial burdens, intensified tissue injury, hyperactive proinflammatory cytokines, and systemic bacterial dissemination as compared with WT mice. Knocking down Cav1 by a dominant negative approach in lung epithelial MLE-12 cells resulted in similar outcomes (decreased bacterial clearance and increased proinflammatory cytokine production). Furthermore, we revealed that STAT5 influences the GSK3β-β-catenin-Akt pathway, which contributes to the intensive inflammatory response and rapid infection dissemination seen in Cav1 deficiency. Collectively, our findings indicate that Cav1 may offer resistance to K. pneumoniae infection, by affecting both systemic and local production of proinflammatory cytokines via the actions of STAT5 and the GSK3β-β-catenin-Akt pathway.
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Affiliation(s)
- Qiang Guo
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota 58203, USA
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Yan C, Wang X, Cao J, Wu M, Gao H. CCAAT/enhancer-binding protein γ is a critical regulator of IL-1β-induced IL-6 production in alveolar epithelial cells. PLoS One 2012; 7:e35492. [PMID: 22558159 PMCID: PMC3338717 DOI: 10.1371/journal.pone.0035492] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/19/2012] [Indexed: 01/19/2023] Open
Abstract
CCAAT/enhancer binding protein γ (C/EBPγ) is a member of the C/EBP family of transcription factors, which lacks known activation domains. C/EBPγ was originally described as an inhibitor of C/EBP transactivation potential. However, previous study demonstrates that C/EBPγ augments the C/EBPβ stimulatory activity in lipopolysaccharide induction of IL-6 promoter in a B lymphoblast cell line. These data indicate a complexing functional role for C/EBPγ in regulating gene expression. Furthermore, the expression and function of C/EBPγ during inflammation are still largely unknown. In this study, we demonstrate that C/EBPγ activation was induced by IL-1β treatment in lung epithelial cells. Importantly, we demonstrate for the first time that C/EBPγ plays a critical role in regulating IL-1β-induced IL-6 expression in both mouse primary alveolar type II epithelial cells and a lung epithelial cell line, MLE12. We further provide the evidence that C/EBPγ inhibits IL-6 expression by inhibiting C/EBPβ but not NF-κB stimulatory activity in MLE12 cells. These findings suggest that C/EBPγ is a key transcription factor that regulates the IL-6 expression in alveolar epithelial cells, and may play an important regulatory role in lung inflammatory responses.
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Affiliation(s)
- Chunguang Yan
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Ximo Wang
- Department of Surgery, Tianjin Union Medical Center, Nankai University Affiliated Hospital, Tianjin, China
| | - Jay Cao
- Agricultural Research Service, Grand Forks Human Nutrition Research Center, United States Department of Agriculture, Grand Forks, North Dakota, United States of America
| | - Min Wu
- Department of Biochemistry and Molecular Biology, University of North Dakota, Grand Forks, North Dakota, United States of America
- * E-mail: (HG); (MW)
| | - Hongwei Gao
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (HG); (MW)
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Yuan K, Huang C, Fox J, Laturnus D, Carlson E, Zhang B, Yin Q, Gao H, Wu M. Autophagy plays an essential role in the clearance of Pseudomonas aeruginosa by alveolar macrophages. J Cell Sci 2012; 125:507-15. [PMID: 22302984 DOI: 10.1242/jcs.094573] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Intracellular bacteria have been shown to cause autophagy, which impacts infectious outcomes, whereas extracellular bacteria have not been reported to activate autophagy. Here, we demonstrate that Pseudomonas aeruginosa, a Gram-negative extracellular bacterium, activates autophagy with considerably increased LC3 punctation in both an alveolar macrophage cell line (MH-S) and primary alveolar macrophages. Using the LC3 Gly120 mutant, we successfully demonstrated a hallmark of autophagy, conjugation of LC3 to phosphatidylethanolamine (PE). The accumulation of typical autophagosomes with double membranes was identified morphologically by transmission electron microscopy (TEM). Furthermore, the increase of PE-conjugated LC3 was indeed induced by infection rather than inhibition of lysosome degradation. P. aeruginosa induced autophagy through the classical beclin-1-Atg7-Atg5 pathway as determined by specific siRNA analysis. Rapamycin and IFN-γ (autophagy inducers) augmented bacterial clearance, whereas beclin-1 and Atg5 knockdown reduced intracellular bacteria. Thus, P. aeruginosa-induced autophagy represents a host protective mechanism, providing new insight into the pathogenesis of this infection.
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Affiliation(s)
- Kefei Yuan
- The State Key Laboratory for Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
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Piao MJ, Kim KC, Choi JY, Choi J, Hyun JW. Silver nanoparticles down-regulate Nrf2-mediated 8-oxoguanine DNA glycosylase 1 through inactivation of extracellular regulated kinase and protein kinase B in human Chang liver cells. Toxicol Lett 2011; 207:143-8. [PMID: 21925250 DOI: 10.1016/j.toxlet.2011.09.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/03/2011] [Accepted: 09/03/2011] [Indexed: 12/30/2022]
Abstract
Recently, we reported that silver nanoparticles (AgNPs) induced reactive oxygen species (ROS) generation and the resultant oxidative stress contributes to the cell damage associated with AgNPs. 8-Oxoguanine (8-oxoG) is sensitive marker of ROS-induced DNA damage. 8-Oxoguanine DNA glycosylase 1 (OGG1) is an important DNA repair enzyme that recognizes and excises 8-oxoG. The aim of the present study was to examine the effect of AgNPs-induced oxidative stress on OGG1 and to elucidate mechanisms underlying AgNPs toxicity. AgNPs decreased OGG1 mRNA and protein expression, resulting in decreased OGG1 activity. Decreased OGG1 activity in AgNPs-treated cells led to increased 8-oxoG levels. The transcription factor NF-E2-related factor 2 (Nrf2) is an important factor in the inducible regulation of OGG1. AgNPs treatment decreased nuclear Nrf2 expression, translocation into nucleus, and transcriptional activity of Nrf2. Extracellular regulated kinase (ERK) and protein kinase B (PKB, AKT), which are upstream of Nrf2, contribute to OGG1 expression. AgNPs attenuated both active forms of ERK and AKT protein expression, resulting in suppression of Nrf2 and decrease of OGG1 expression. These studies demonstrate that down-regulation of Nrf2-mediated OGG1 in exposure to AgNPs occurs through ERK and AKT inactivation.
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Affiliation(s)
- Mei Jing Piao
- School of Medicine and Applied Radiological Science Research Institute, Jeju National University, Jeju, Republic of Korea
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32
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Consequences of hyperoxia and the toxicity of oxygen in the lung. Nurs Res Pract 2011; 2011:260482. [PMID: 21994818 PMCID: PMC3169834 DOI: 10.1155/2011/260482] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 03/29/2011] [Accepted: 04/04/2011] [Indexed: 11/18/2022] Open
Abstract
Oxygen (O(2)) is life essential but as a drug has a maximum positive biological benefit and accompanying toxicity effects. Oxygen is therapeutic for treatment of hypoxemia and hypoxia associated with many pathological processes. Pathophysiological processes are associated with increased levels of hyperoxia-induced reactive O(2) species (ROS) which may readily react with surrounding biological tissues, damaging lipids, proteins, and nucleic acids. Protective antioxidant defenses can become overwhelmed with ROS leading to oxidative stress. Activated alveolar capillary endothelium is characterized by increased adhesiveness causing accumulation of cell populations such as neutrophils, which are a source of ROS. Increased levels of ROS cause hyperpermeability, coagulopathy, and collagen deposition as well as other irreversible changes occurring within the alveolar space. In hyperoxia, multiple signaling pathways determine the pulmonary cellular response: apoptosis, necrosis, or repair. Understanding the effects of O(2) administration is important to prevent inadvertent alveolar damage caused by hyperoxia in patients requiring supplemental oxygenation.
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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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Zhang R, Kang KA, Piao MJ, Kim KC, Lee NH, You HJ, Hyun JW. Triphlorethol-a improves the non-homologous end joining and base-excision repair capacity impaired by formaldehyde. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2011; 74:811-821. [PMID: 21541882 DOI: 10.1080/15287394.2011.567957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Formaldehyde (HCHO) generates reactive oxygen species (ROS) that induce DNA base modifications and DNA strand breaks and contributes to mutagenesis and other pathological processes. DNA non-homologous end-joining (NHEJ), a major mechanism for repairing DNA double-stranded breaks (DSB) in mammalian cells, involves the formation of a Ku protein heterodimer and recruitment of a DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to the site of DNA damage. HCHO treatment induced DSB and decreased the protein expressions of Ku 70 and phosphorylated DNA-PKcs. Triphlorethol-A reduced DNA strand breaks and restored the expression of NHEJ-related proteins. In response to oxidative DNA base damage, 8-oxoguanine DNA glycosylase 1 (OGG1) plays a vital role in repair of 8-hydroxy-2'-deoxyguanosine (8-OhdG) via the base-excision repair (BER) process. In this study, HCHO significantly increased 8-OhdG levels, whereas triphlorethol-A lowered 8-OhdG levels. Suppression of 8-OhdG formation by triphlorethol-A was related to enhanced OGG1 protein expression. Triphlorethol-A also enhanced the expression of phosphorylated Akt (the active form of Akt), a regulator of OGG1, which was found to be decreased by HCHO treatment. The phosphoinositol 3-kinase (PI3K)-specific inhibitor LY294002 abolished the cytoprotective effects induced by triphlorethol-A, suggesting that OGG1 restoration by triphlorethol-A is involved in the PI3K/Akt pathway. These results suggest that triphlorethol-A may protect cells against HCHO-induced DNA damage via enhancement of NHEJ and BER capacity.
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Affiliation(s)
- Rui Zhang
- School of Medicine and Veterinary Medical Research Institute, Jeju National University, Jeju, Korea
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Host DNA repair proteins in response to Pseudomonas aeruginosa in lung epithelial cells and in mice. Infect Immun 2010; 79:75-87. [PMID: 20956573 DOI: 10.1128/iai.00815-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Although DNA repair proteins in bacteria are critical for pathogens' genome stability and for subverting the host defense, the role of host DNA repair proteins in response to bacterial infection is poorly defined. Here, we demonstrate, for the first time, that infection with the Gram-negative bacterium Pseudomonas aeruginosa significantly altered the expression and enzymatic activity of 8-oxoguanine DNA glycosylase (OGG1) in lung epithelial cells. Downregulation of OGG1 by a small interfering RNA strategy resulted in severe DNA damage and cell death. In addition, acetylation of OGG1 is required for host responses to bacterial genotoxicity, as mutations of OGG1 acetylation sites increased Cockayne syndrome group B (CSB) protein expression. These results also indicate that CSB may be involved in DNA repair activity during infection. Furthermore, OGG1 knockout mice exhibited increased lung injury after infection with P. aeruginosa, as demonstrated by higher myeloperoxidase activity and lipid peroxidation. Together, our studies indicate that P. aeruginosa infection induces significant DNA damage in host cells and that DNA repair proteins play a critical role in the host response to P. aeruginosa infection, serving as promising targets for the treatment of this condition and perhaps more broadly Gram-negative bacterial infections.
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Wu M, Audet A, Cusic J, Seeger D, Cochran R, Ghribi O. Broad DNA repair responses in neural injury are associated with activation of the IL-6 pathway in cholesterol-fed rabbits. J Neurochem 2009; 111:1011-21. [PMID: 19765189 DOI: 10.1111/j.1471-4159.2009.06390.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The importance of DNA repair in the pathogenic mechanism of Alzheimer's Disease (AD) is still poorly understood. Here, we report that a broad range of responses by DNA repair proteins plays a critical role in the regulation of inflammatory response in rabbits fed with cholesterol-rich diet, a model system for AD. We found accumulation of oxodG DNA adduct in the brain of rabbits fed with cholesterol-enriched diets compared to control diets, which subsequently induced a broad range of DNA repair protein activities. Also, the hippocampus was identified as the primary site of oxidative DNA damage and elevated OGG1 activity. In addition, a physical interaction between XPB and OGG1 may account for a potential mechanism involving these DNA repair responses. DNA repair proteins also impact activation of various signaling cascades, including Src in response to cholesterol oxidation. Furthermore, OGG1 deficient mice showed no IL-6 activation as seen in wt mice but a drastic increase of TNF-alpha, a pro-inflammatory cytokine. Thus, OGG1 may be associated with cytokine production induced by high cholesterol levels, impacting neurodegeneration. Together, our studies suggest that critical DNA repair proteins are associated with development of AD, and may serve as potential targets for the treatment of AD.
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Affiliation(s)
- Min Wu
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58203, USA.
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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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Youn CK, Jun JY, Hyun JW, Hwang G, Lee BR, Chung MH, Chang IY, You HJ. hMTH1 depletion promotes oxidative-stress-induced apoptosis through a Noxa- and caspase-3/7-mediated signaling pathway. DNA Repair (Amst) 2008; 7:1809-23. [DOI: 10.1016/j.dnarep.2008.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Revised: 07/09/2008] [Accepted: 07/10/2008] [Indexed: 12/30/2022]
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Su ZX, Peng T, Ye XP, Xiao KY, Shang LM, Su M, Li LQ. Effect of preoperative chemotherapy on the expression of human 8-oxoGuanine DNA glycosylase-1 and poly ADP-ribose polymerase in hepatocellular carcinoma. Shijie Huaren Xiaohua Zazhi 2008; 16:1412-1416. [DOI: 10.11569/wcjd.v16.i13.1412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the effect of preoperative chemotherapy on repair mechanism.
METHODS: EnVision immunohistochemical method was used to detect the expression of human 8-oxoGuanine DNA glycosylase-1 (hOGG1) and poly ADP-ribose polymerase (PARP) in normal liver tissues (n = 41), hepatocellular carcinoma (HCC) and its surrounding tissues (n = 187; preoperative chemotherapy, n = 88; without preoperative chemotherapy, n = 99).
RESULTS: The expression levels of hOGG1 in nuclei were increased ordinally, while those of PARP were decreased ordinally in HCC tissues without preoperative chemotherapy, HCC tissues received preoperative chemotherapy, and normal liver tissues, and there were marked difference between the three groups (all P < 0.05). COX multivariate analysis of prognosis indicated that the risk factors for HCC recurrence included the positive degree of PARP expression (P = 0.038), alanine aminotransferase (ALT) level (P = 0.001), and histological grades (P = 0.040), while the protective factors included the peripheral blood lymphocyte count (P = 0.026) and chemotherapy (P = 0.049).
CONCLUSION: Preoperative chemotherapy promote the ability of DNA repair in HCC tissues.
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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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41
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Youn CK, Song PI, Kim MH, Kim JS, Hyun JW, Choi SJ, Yoon SP, Chung MH, Chang IY, You HJ. Human 8-oxoguanine DNA glycosylase suppresses the oxidative stress induced apoptosis through a p53-mediated signaling pathway in human fibroblasts. Mol Cancer Res 2007; 5:1083-98. [PMID: 17951408 DOI: 10.1158/1541-7786.mcr-06-0432] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human 8-oxoguanine DNA glycosylase (hOGG1) is the main defense enzyme against mutagenic effects of cellular 7,8-dihydro-8-oxoguanine. In this study, we investigated the biological role of hOGG1 in DNA damage-related apoptosis induced by hydrogen peroxide (H(2)O(2))-derived oxidative stress. The down-regulated expression of hOGG1 by its small interfering RNA prominently triggers the H(2)O(2)-induced apoptosis in human fibroblasts GM00637 and human lung carcinoma H1299 cells via the p53-mediated apoptotic pathway. However, the apoptotic responses were specifically inhibited by hOGG1 overexpression. The p53-small interfering RNA transfection into the hOGG1-deficient GM00637 markedly inhibited the H(2)O(2)-induced activation of p53-downstream target proteins such as p21, Noxa, and caspase-3/7, which eventually resulted in the increased cell viability. Although the cell viability of hOGG1-knockdown H1299 p53 null cells was similar to that of the hOGG1 wild-type H1299, after the overexpression of p53 the hOGG1-knockdown H1299 showed the significantly decreased cell viability compared with that of the hOGG1 wild-type H1299 at the same experimental condition. Moreover, the array comparative genome hybridization analyses revealed that the hOGG1-deficient GM00637 showed more significant changes in the copy number of large regions of their chromosomes in response to H(2)O(2) treatment. Therefore, we suggest that although p53 is a major modulator of apoptosis, hOGG1 also plays a pivotal role in protecting cells against the H(2)O(2)-induced apoptosis at the upstream of the p53-dependent pathway to confer a survival advantage to human fibroblasts and human lung carcinomas through maintaining their genomic stability.
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Affiliation(s)
- Cha-Kyung Youn
- Korean DNA Repair Research Center, Department of Pharmacology, Chosun University School of Medicine, Gwangju, South Korea
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42
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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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43
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Xu D, Guthrie JR, Mabry S, Sack TM, Truog WE. Mitochondrial aldehyde dehydrogenase attenuates hyperoxia-induced cell death through activation of ERK/MAPK and PI3K-Akt pathways in lung epithelial cells. Am J Physiol Lung Cell Mol Physiol 2006; 291:L966-75. [PMID: 16782756 DOI: 10.1152/ajplung.00045.2006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Oxygen toxicity is one of the major risk factors in the development of the chronic lung disease or bronchopulmonary dysplasia in premature infants. Using proteomic analysis, we discovered that mitochondrial aldehyde dehydrogenase (mtALDH or ALDH2) was downregulated in neonatal rat lung after hyperoxic exposure. To study the role of mtALDH in hyperoxic lung injury, we overexpressed mtALDH in human lung epithelial cells (A549) and found that mtALDH significantly reduced hyperoxia-induced cell death. Compared with control cells (Neo-A549), the necrotic cell death in mtALDH-overexpressing cells (mtALDH-A549) decreased from 25.3 to 6.5%, 50.5 to 9.1%, and 52.4 to 15.1% after 24-, 48-, and 72-h hyperoxic exposure, respectively. The levels of intracellular and mitochondria-derived reactive oxygen species (ROS) in mtALDH-A549 cells after hyperoxic exposure were significantly lowered compared with Neo-A549 cells. mtALDH overexpression significantly stimulated extracellular signal-regulated kinase (ERK) phosphorylation under normoxic and hyperoxic conditions. Inhibition of ERK phosphorylation partially eliminated the protective effect of mtALDH in hyperoxia-induced cell death, suggesting ERK activation by mtALDH conferred cellular resistance to hyperoxia. mtALDH overexpression augmented Akt phosphorylation and maintained the total Akt level in mtALDH-A549 cells under normoxic and hyperoxic conditions. Inhibition of phosphatidylinositol 3-kinase (PI3K) activation by LY294002 in mtALDH-A549 cells significantly increased necrotic cell death after hyperoxic exposure, indicating that PI3K-Akt activation by mtALDH played an important role in cell survival after hyperoxia. Taken together, these data demonstrate that mtALDH overexpression attenuates hyperoxia-induced cell death in lung epithelial cells through reduction of ROS, activation of ERK/MAPK, and PI3K-Akt cell survival signaling pathways.
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Affiliation(s)
- Dong Xu
- Neonatology Research Laboratory, Children's Mercy Hospital, Pediatric Research Center, 4th Floor, 2401 Gillham Rd., Kansas City, MO 64108, USA.
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Kannan S, Audet A, Knittel J, Mullegama S, Gao GF, Wu M. Src kinase Lyn is crucial for Pseudomonas aeruginosa internalization into lung cells. Eur J Immunol 2006; 36:1739-52. [PMID: 16791881 DOI: 10.1002/eji.200635973] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Lyn is an important B cell signaling kinase of the Src tyrosine kinase family with a broad range of functions from cytoskeletal changes to induction of apoptosis. However, the role of Lyn in infectious diseases is not clear. Here, we demonstrate that Lyn activation by phosphorylation significantly impacted invasion of an alveolar epithelial cell line, primary lung cells, and rat lungs by Pseudomonas aeruginosa (PA), a common opportunistic lung pathogen affecting individuals with deficient lung immunity. Our results indicate that activation of Lyn and its interaction with rafts and TLR2, played an important role in the initial stages of PA interaction with host cells. The role of Lyn was further evaluated using the pharmacologic Src-specific inhibitor PP2, a dominant negative mutant, and finally confirmed with Lyn-deficient (Lyn(-/-)) bone marrow-derived mast cells. Inhibition of Lyn's function by above approaches prevented PA internalization. Moreover, blocking of Lyn also affected downstream events: induction of inflammatory cytokines and apoptosis. This report brings out a new role of Lyn in infectious diseases and indicates potential new targets for prevention and treatment of infections.
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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 558203, USA
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