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Tatler AL, Habgood A, Porte J, John AE, Stavrou A, Hodge E, Kerama-Likoko C, Violette SM, Weinreb PH, Knox AJ, Laurent G, Parfrey H, Wolters PJ, Wallace W, Alberti S, Nordheim A, Jenkins G. Reduced Ets Domain-containing Protein Elk1 Promotes Pulmonary Fibrosis via Increased Integrin αvβ6 Expression. J Biol Chem 2016; 291:9540-53. [PMID: 26861876 PMCID: PMC4850293 DOI: 10.1074/jbc.m115.692368] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 02/09/2016] [Indexed: 12/20/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with high mortality. Active TGFβ1 is considered central to the pathogenesis of IPF. A major mechanism of TGFβ1 activation in the lung involves the epithelially restricted αvβ6 integrin. Expression of the αvβ6 integrin is dramatically increased in IPF. How αvβ6 integrin expression is regulated in the pulmonary epithelium is unknown. Here we identify a region in the β6 subunit gene (ITGB6) promoter acting to markedly repress basal gene transcription, which responds to both the Ets domain-containing protein Elk1 (Elk1) and the glucocorticoid receptor (GR). Both Elk1 and GR can regulate αvβ6 integrin expression in vitro We demonstrate Elk1 binding to the ITGB6 promoter basally and that manipulation of Elk1 or Elk1 binding alters ITGB6 promoter activity, gene transcription, and αvβ6 integrin expression. Crucially, we find that loss of Elk1 causes enhanced Itgb6 expression and exaggerated lung fibrosis in an in vivo model of fibrosis, whereas the GR agonist dexamethasone inhibits Itgb6 expression. Moreover, Elk1 dysregulation is present in epithelium from patients with IPF. These data reveal a novel role for Elk1 regulating ITGB6 expression and highlight how dysregulation of Elk1 can contribute to human disease.
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Affiliation(s)
- Amanda L Tatler
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom,
| | - Anthony Habgood
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | - Joanne Porte
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | - Alison E John
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | - Anastasios Stavrou
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | - Emily Hodge
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | - Cheryl Kerama-Likoko
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | | | | | - Alan J Knox
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
| | - Geoffrey Laurent
- the Centre for Respiratory Research, University College London, London WC1E 6JF, United Kingdom, the Centre for Cell Therapy and Regenerative Medicine, University of Western Australia, Crawley WA 6009, Australia
| | - Helen Parfrey
- the Department of Medicine, University of Cambridge and Papworth Hospital NHSFT, Cambridge CB2 0SP, United Kingdom
| | - Paul John Wolters
- the Department of Medicine, University of California, San Francisco, San Francisco, California 94143
| | - William Wallace
- the Division of Pathology, University of Edinburgh, Edinburgh EH4 2XR, United Kingdom, and
| | - Siegfried Alberti
- the Interfaculty Institute of Cell Biology, Tübingen University, Tübingen 72076, Germany
| | - Alfred Nordheim
- the Interfaculty Institute of Cell Biology, Tübingen University, Tübingen 72076, Germany
| | - Gisli Jenkins
- From the Division of Respiratory Medicine, University of Nottingham, Nottingham University Hospitals, City Campus, Nottingham NG5 1PB, United Kingdom
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Guo P, Shi ZL, Liu A, Lin T, Bi F, Shi M, Yan SG. Effects of cartilage oligomeric matrix protein on bone morphogenetic protein-2-induced differentiation of mesenchymal stem cells. Orthop Surg 2015; 6:280-7. [PMID: 25430711 DOI: 10.1111/os.12135] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 05/27/2014] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE To investigate the effect of overexpression of cartilage oligomeric matrix protein (COMP) on bone morphogenetic protein-2 (BMP-2) induced osteogenic and chondrogenic differentiation of mesenchymal stem cells (MSCs). In this study, we used liposomes to transfect MSCs with plasmid encoding COMP and then induced the transfected MSCs to differentiate in osteogenic and chondrogenic differentiation media containing BMP-2. METHODS MSCs transfected with plasmid DNA encoding recombinant human COMP were induced to differentiate into osteocytes and chondrocytes by BMP-2. Real-time polymerase chain reaction (PCR) assays of osteogenesis-related markers (collagen type I alpha 1, runt-related transcription factor 2, osteopontin, bone gla protein) and chondrogenesis-related markers (collagen type II alpha 1, sry-related high-mobility group box 9, Aggrecan) was performed to evaluate the process of cell differentiation. Cell differentiation was evaluated by alkaline phosphatase (ALP) and Alizarin red S stains for osteogenic differentiation and alcian blue staining for chondrogenic differentiation. RESULTS Real-time PCR assay showed significantly greater COMP expression by MSCs when COMP gene had been transfected into the cells (P < 0.01). Overexpression of COMP down-regulated expression of osteogenesis-related markers and up-regulated expression of chondrogenesis-related markers. ALP staining and Alizarin red S staining were weakened, whereas alcian blue staining was enhanced. CONCLUSION Overexpression of COMP inhibits BMP-2-induced osteogenic differentiation and promotes BMP-2-induced chondrogenic differentiation. These findings may provide new insights for cartilage tissue engineering. The experiments in the present study were all in vitro, which has potential limitations. Further in vivo studies to investigate the effects of COMP in animal models are necessary, which will be the next step in our research.
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Affiliation(s)
- Peng Guo
- Department of Orthopaedic Surgery, The Second Affiliated Hospital, Medical College of Zhejiang University, Hangzhou, China
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Belcastro R, Lopez L, Li J, Masood A, Tanswell AK. Chronic lung injury in the neonatal rat: up-regulation of TGFβ1 and nitration of IGF-R1 by peroxynitrite as likely contributors to impaired alveologenesis. Free Radic Biol Med 2015; 80:1-11. [PMID: 25514442 DOI: 10.1016/j.freeradbiomed.2014.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/22/2014] [Accepted: 12/05/2014] [Indexed: 10/24/2022]
Abstract
Postnatal alveolarization is regulated by a number of growth factors, including insulin-like growth factor-I (IGF-I) acting through the insulin-like growth factor receptor-1 (IGF-R1). Exposure of the neonatal rat lung to 60% O2 for 14 days results in impairments of lung cell proliferation, secondary crest formation, and alveologenesis. This lung injury is mediated by peroxynitrite and is prevented by treatment with a peroxynitrite decomposition catalyst. We hypothesized that one of the mechanisms by which peroxynitrite induces lung injury in 60% O2 is through nitration and inactivation of critical growth factors or their receptors. Increased nitration of both IGF-I and IGF-R1 was evident in 60% O2-exposed lungs, which was reversible by concurrent treatment with a peroxynitrite decomposition catalyst. Increased nitration of the IGF-R1 was associated with its reduced activation, as assessed by IGF-R1 phosphotyrosine content. IGF-I displacement binding plots were conducted in vitro using rat fetal lung distal epithelial cells which respond to IGF-I by an increase in DNA synthesis. When IGF-I was nitrated to a degree similar to that observed in vivo there was minimal, if any, effect on IGF-I displacement binding. In contrast, nitrating cell IGF-R1 to a similar degree to that observed in vivo completely prevented specific binding of IGF-I to the IGF-R1, and attenuated an IGF-I-mediated increase in DNA synthesis. Additionally, we hypothesized that peroxynitrite also impairs alveologenesis by being an upstream regulator of the growth inhibitor, TGFβ1. That 60% O2-induced impairment of alveologenesis was mediated in part by TGFβ1 was confirmed by demonstrating an improvement in secondary crest formation when 60% O2-exposed pups received concurrent treatment with the TGFß1 activin receptor-like kinase, SB 431542. That the increased TGFβ1 content in lungs of pups exposed to 60% O2 was regulated by peroxynitrite was confirmed by its attenuation by concurrent treatment with a peroxynitrite decomposition catalyst. We conclude that peroxynitrite contributes to the impaired alveologenesis observed following the exposure of neonatal rats to 60% O2 both by preventing binding of IGF-I to the IGF-R1, secondary to nitration of the IGF-R1, and by causing an up-regulation of the growth inhibitor, TGFβ1.
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Affiliation(s)
- Rosetta Belcastro
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1X8
| | - Lianet Lopez
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1X8
| | - Jun Li
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1X8
| | - Azhar Masood
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1X8; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8
| | - A Keith Tanswell
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1X8; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8; Department of Paediatrics, University of Toronto, Toronto, Ontario M5G 1X8.
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Cartilage oligomeric matrix protein gene multilayers inhibit osteogenic differentiation and promote chondrogenic differentiation of mesenchymal stem cells. Int J Mol Sci 2014; 15:20117-33. [PMID: 25380520 PMCID: PMC4264159 DOI: 10.3390/ijms151120117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 09/22/2014] [Accepted: 10/27/2014] [Indexed: 01/09/2023] Open
Abstract
There are still many challenges to acquire the optimal integration of biomedical materials with the surrounding tissues. Gene coatings on the surface of biomaterials may offer an effective approach to solve the problem. In order to investigate the gene multilayers mediated differentiation of mesenchymal stem cells (MSCs), gene functionalized films of hyaluronic acid (HA) and lipid-DNA complex (LDc) encoding cartilage oligomeric matrix protein (COMP) were constructed in this study via the layer-by-layer self-assembly technique. Characterizations of the HA/DNA multilayered films indicated the successful build-up process. Cells could be directly transfected by gene films and a higher expression could be obtained with the increasing bilayer number. The multilayered films were stable for a long period and DNA could be easily released in an enzymatic condition. Real-time polymerase chain reaction (RT-PCR) assay presented significantly higher (p < 0.01) COMP expression of MSCs cultured with HA/COMP multilayered films. Compared with control groups, the osteogenic gene expression levels of MSCs with HA/COMP multilayered films were down-regulated while the chondrogenic gene expression levels were up-regulated. Similarly, the alkaline phosphatase (ALP) staining and Alizarin red S staining of MSCs with HA/COMP films were weakened while the alcian blue staining was enhanced. These results demonstrated that HA/COMP multilayered films could inhibit osteogenic differentiation and promote chondrogenic differentiation of MSCs, which might provide new insight for physiological ligament-bone healing.
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Jamal M, Masood A, Belcastro R, Lopez L, Li J, Belik J, Jankov RP, Keith Tanswell A. Lipid hydroperoxide formation regulates postnatal rat lung cell apoptosis and alveologenesis. Free Radic Biol Med 2013. [PMID: 23195685 DOI: 10.1016/j.freeradbiomed.2012.11.012] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An acute increase in oxygen tension after birth imposes an oxidative stress upon the lung. We hypothesized that the resultant increase in reactive oxygen species, specifically lipid hydroperoxides, would trigger postnatal alveologenesis and physiological lung cell apoptosis in the neonatal rat. Neonatal rats were either untreated or treated daily with subcutaneous vehicle or diphenyl phenyl diamine, a scavenger of lipid hydroperoxides and inhibitor of lipid peroxidation, from day 1 to 6 of life. Alveolar formation and physiological lung cell apoptosis were assessed by morphometry, immunohistochemistry, and Western blot analyses on day 7 samples. Substitution experiments were conducted using the prototypic lipid hydroperoxide t-butylhydroperoxide. At a minimum effective dose of 15μg/g body wt, treatment with diphenyl phenyl diamine resulted in a significant increase in tissue fraction and mean linear intercept and significant reductions in small peripheral blood vessels, secondary crest formation, lung and secondary crest cell DNA synthesis, and estimated alveolar number. Decreased numbers of apoptotic type II pneumocytes and mesenchymal cells, and decreased contents of proapoptotic cleaved caspase-3 and -7 and cytoplasmic cytochrome c, and an increase in antiapoptotic Bcl-xL were found in lungs treated with diphenyl phenyl diamine. A prevention of selected changes induced by diphenyl phenyl diamine was observed with concurrent treatment with intraperitoneal t-butylhydroperoxide, at a minimally effective dose of 187μg/g body wt. We conclude that oxidative stress after birth induces lipid hydroperoxide formation, which, in turn, triggers postnatal alveologenesis and physiological lung cell apoptosis in the neonatal rat.
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Affiliation(s)
- Mobin Jamal
- Lung Biology Programme, Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, ON M5G 1X8, Canada
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Oberfeld B, Ruffieux-Daidié D, Vitagliano JJ, Pos KM, Verrey F, Staub O. Ubiquitin-specific protease 2-45 (Usp2-45) binds to epithelial Na+ channel (ENaC)-ubiquitylating enzyme Nedd4-2. Am J Physiol Renal Physiol 2011; 301:F189-96. [PMID: 21478478 DOI: 10.1152/ajprenal.00487.2010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Regulation of the epithelial Na(+) channel (ENaC) by ubiquitylation is controlled by the activity of two counteracting enzymes, the E3 ubiquitin-protein ligase Nedd4-2 (mouse ortholog of human Nedd4L) and the ubiquitin-specific protease Usp2-45. Previously, Usp2-45 was shown to decrease ubiquitylation and to increase surface function of ENaC in Xenopus laevis oocytes, whereas the splice variant Usp2-69, which has a different N-terminal domain, was inactive toward ENaC. It is shown here that the catalytic core of Usp2 lacking the N-terminal domain has a reduced ability relative to Usp2-45 to enhance ENaC activity in Xenopus oocytes. In contrast, its catalytic activity toward the artificial substrate ubiquitin-AMC is fully maintained. The interaction of Usp2-45 with ENaC exogenously expressed in HEK293 cells was tested by coimmunoprecipitation. The data indicate that different combinations of ENaC subunits, as well as the α-ENaC cytoplasmic N-terminal but not C-terminal domain, coprecipitate with Usp2-45. This interaction is decreased but not abolished when the cytoplasmic ubiquitylation sites of ENaC are mutated. Importantly, coimmunoprecipitation in HEK293 cells and GST pull-down of purified recombinant proteins show that both the catalytic domain and the N-terminal tail of Usp2-45 physically interact with the HECT domain of Nedd4-2. Taken together, the data support the conclusion that Usp2-45 action on ENaC is promoted by various interactions, including through binding to Nedd4-2 that is suggested to position Usp2-45 favorably for ENaC deubiquitylation.
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Affiliation(s)
- Benjamin Oberfeld
- Institute of Physiology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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7
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Ruffieux-Daidié D, Staub O. Intracellular ubiquitylation of the epithelial Na+ channel controls extracellular proteolytic channel activation via conformational change. J Biol Chem 2010; 286:2416-24. [PMID: 21084303 DOI: 10.1074/jbc.m110.176156] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The epithelial Na(+) channel ENaC is a key player in the maintenance of whole body Na(+) balance, and consequently of blood pressure. It is tightly regulated by numerous signaling pathways including ubiquitylation via the ubiquitin-protein ligase Nedd4-2. This mechanism is itself under the control of several kinases, which phosphorylate Nedd4-2, thereby interfering with ENaC/Nedd4-2 interaction, or by Usp2-45, which binds to and deubiquitylates ENaC. Another, different regulatory mechanism concerns the proteolytic activation of ENaC, during which the channel is cleaved on its luminal side by intracellular convertases such as furin, and further activated by extracellular proteases such as CAP-1. This process is regulated as well but the underlying mechanisms are not understood. Previously, evidence was provided that the ubiquitylation status of ENaC may affect the cleavage of the channel. When ubiquitylation of ENaC was reduced, either by co-expressing Usp2-45, or mutating either the ENaC PY-motifs (i.e. the binding sites for Nedd4-2) or intracellular lysines (i.e. ubiquitylation sites), the level of channel cleavage was increased. Here we demonstrate that lysine-mutated ENaC channels are not ubiquitylated at the cell surface, are preferentially cleaved, and Usp2-45 does not affect their cleavage efficiency. We further show by limited proteolysis that the intracellular ubiquitylation status of ENaC affects the extracellular conformation of αENaC, by demonstrating that non-ubiquitylated channels are more efficiently cleaved when treated with extracellularly added trypsin or chymotrypsin. These results present a new paradigm in which an intracellular, post-translational modification (e.g. ubiquitylation) of a transmembrane protein can affect its extracellular conformation.
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Buzder T, Yin X, Wang X, Banfalvi G, Basnakian AG. Uptake of foreign nucleic acids in kidney tubular epithelial cells deficient in proapoptotic endonucleases. DNA Cell Biol 2009; 28:435-42. [PMID: 19558214 DOI: 10.1089/dna.2008.0850] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Degradation of DNA during gene delivery is an obstacle for gene transfer and for gene therapy. DNases play a major role in degrading foreign DNA. However, which of the DNases are involved and whether their inactivation can improve gene delivery have not been studied. We have recently identified deoxyribonuclease I (DNase I) and endonuclease G (EndoG) as the major degradative enzymes in the mouse kidney proximal tubule epithelial (TKPTS) cells. In this study, we used immortalized mouse TKPTS cells and primary tubular epithelial cells isolated from DNase I or EndoG knockout (KO) mice and examined the degradation of plasmid DNA during its uptake. DNase I and EndoG KO cells showed a higher rate of transfection by pECFP-N1 plasmid than wild-type cells. In addition, EndoG KO cells prevented the uptake of fluorescent-labeled RNA. Complete inhibition of secreted DNase I by G-actin did not improve plasmid transfection, indicating that only intracellular DNase I affects DNA stability. Data demonstrate the importance of DNase I and EndoG in host cell defense against gene and RNA delivery to renal tubular epithelial cells in vitro.
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Affiliation(s)
- Timea Buzder
- Division of Nephrology, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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9
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Mok PL, Cheong SK, Leong CF, Othman A. In vitro expression of erythropoietin by transfected human mesenchymal stromal cells. Cytotherapy 2008; 10:116-24. [PMID: 18368590 DOI: 10.1080/14653240701816996] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Mesenchymal stromal cells (MSC) are pluripotent progenitor cells that can be found in human bone marrow (BM). These cells have low immunogenicity and could suppress alloreactive T-cell responses. In the current study, MSC were tested for their capacity to carry and deliver the erythropoietin (EPO) gene in vitro. METHODS Expanded BM MSC was transfected with EPO-encoded plasmid pMCV1.2 and EPO-encoded MIDGE (minimalistic immunologically defined gene expression) vector by electroporation. The expressed EPO was used to induce hematopoietic stem cells (HSC) into erythroid colonies. RESULTS The results showed that the MIDGE vector was more effective and stable than the plasmid (pMCV1.2) in delivering EPO gene into MSC. The supernatants containing EPO obtained from the transfected cell culture were able to induce the differentiation of HSC into erythroid colonies. DISCUSSION MSC hold promise as a cell factory for the production of biologic molecules, and MIDGE vector is more effective and stable than the plasmid in nucleofection involving the EPO gene.
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Affiliation(s)
- P-L Mok
- Cellular Therapy Unit, MAKNA-HUKM Cancer Institute, Kuala Lumpur, Malaysia
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10
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Roth CM, Sundaram S. Engineering synthetic vectors for improved DNA delivery: insights from intracellular pathways. Annu Rev Biomed Eng 2004; 6:397-426. [PMID: 15255775 DOI: 10.1146/annurev.bioeng.6.040803.140203] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Significant progress has been made in the area of nonviral gene delivery to date. Yet, synthetic vectors remain less efficient by orders of magnitude than their viral counterparts. Research continues toward unraveling and overcoming various barriers to the efficient delivery of DNA, whether in plasmid form encoding a gene or as an oligonucleotide for the selective inhibition of target gene expression. Novel components for overcoming these hurdles are continually being incorporated into the design of synthetic vectors, leading to increasingly more virus-like particles. Despite these advances, general principles defining the design of synthetic vectors are yet to be developed fully. A more quantitative analysis of the cellular uptake and intracellular processing of these vectors is required for the rational manipulation of vector design. Mathematical frameworks with a more conceptual basis will help obtain an integrated perspective on these complex systems. In this review, we critically examine the progress made toward the improved design of synthetic vectors by the strategic exploitation of intracellular mechanisms and explore newer possibilities to overcome obstacles in the practical realization of this field.
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Affiliation(s)
- Charles M Roth
- Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey 08854, USA.
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Luo X, Belcastro R, Cabacungan J, Hannam V, Negus A, Wen Y, Plumb J, Hu J, Steer B, Koehler DR, Downey GP, Tanswell AK. Transfection of lung cells in vitro and in vivo: effect of antioxidants and intraliposomal bFGF. Am J Physiol Lung Cell Mol Physiol 2003; 284:L817-25. [PMID: 12513969 DOI: 10.1152/ajplung.00479.2001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We hypothesized that constitutive formation of reactive oxygen species by respiratory cells is a barrier to gene transfer when liposome-DNA complexes are used, by contributing to rapid degradation of plasmid DNA. When plasmid DNA is complexed to liposomes it is protected against H(2)O(2)-mediated degradation but not that mediated by the hydroxyl radical. Treatment of distal rat fetal lung epithelial cells (RFL(19)Ep) with the vitamin E analog Trolox (50 microM) reduced intracellular plasmid degradation. Both Trolox (50 microM) and an iron chelator, phenanthroline (0.1 microM), significantly increased transgene expression in RFL(19)Ep approximately twofold, consistent with a hydroxyl radical-mediated inhibition of transgene expression. When basic fibroblast growth factor (bFGF; 20 ng/ml), a growth factor with antioxidant properties, was included within liposomes, we observed a significantly greater enhancement of RFL(19)Ep transgene expression (approximately 2-fold) over that seen with Trolox or phenanthroline. Inclusion of bFGF within liposomes also significantly enhanced (approximately 4-fold) transgene expression in mice following intratracheal instillation.
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Affiliation(s)
- Xiaoping Luo
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
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Thome U, Chen L, Factor P, Dumasius V, Freeman B, Sznajder JI, Matalon S. Na,K-ATPase gene transfer mitigates an oxidant-induced decrease of active sodium transport in rat fetal ATII cells. Am J Respir Cell Mol Biol 2001; 24:245-52. [PMID: 11245623 DOI: 10.1165/ajrcmb.24.3.3994] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We investigated whether adenovirus-mediated transfer of genes encoding for subunits of the Na,K-ATPase increases transepithelial Na(+) transport in rat fetal distal lung epithelial (FDLE) monolayers and renders them more resistant to hydrogen peroxide injury. FDLE cells, isolated from rat fetuses at a gestational age of 19 to 20 d (22 d = term), were seeded on filters and infected with replication-incompetent human type 5 adenoviruses containing complementary DNAs encoding for rat Na,K-ATPase alpha(1) or beta(1) subunits (ad alpha(1) and ad beta(1), respectively). Once confluent monolayers were formed, the filters were mounted in Ussing chambers and short circuit currents (I(SC)) were measured. Increased levels of alpha(1) or beta(1) subunit proteins after infection with ad alpha(1) and ad beta(1), respectively, were confirmed by Western blot analysis. Baseline I(SC) increased after transfection with 2 plaque-forming units (pfu) of ad beta(1) from 5.1 +/- 0.3 to 6.1 +/- 0.3 microA/cm(2) (mean +/- SEM; P < 0.05). Permeabilization of the apical membrane with amphotericin B caused a large increase in I(SC); the ouabain-sensitive component of the amphotericin B-elicited I(SC) (ouab(max)) was increased from 4.0 +/- 0.2 (n = 69) in controls to 4.8 +/- 0.2 (n = 15), 5.9 +/- 0.3 (n = 53), 6.9 +/- 0.4 (n = 25), 7.7 +/- 0.9 (n = 16) in monolayers infected with 1, 2, 11, and 22 pfu of ad beta(1), respectively; transfection with ad alpha(1) had no effect on any measured variables. Further, transfection with ad beta(1) in comparison to noninfected monolayers resulted in higher baseline and ouab(max) I(SC) after injury with 500 microM H(2)O(2). We conclude that overexpression of the beta(1) subunit of the Na,K-ATPase may help maintain normal levels of vectorial Na(+) transport across ATII cell monolayers in pathologic conditions.
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Affiliation(s)
- U Thome
- Departments of Pediatrics and Anesthesiology, University of Alabama at Birmingham, Birmingham, Alabama; and Departments of Medicine, Evanston Northwestern Healthcare and Northwestern University, Chicago, Illinois
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Luo X, Christie NA, McLaughlin MA, Belcastro R, Sedlackova L, Cabacungan J, Freeman BA, Tanswell AK. H2O2 mediates O2 toxicity in cultured fetal rat distal lung epithelial cells. Free Radic Biol Med 1999; 26:1357-68. [PMID: 10401598 DOI: 10.1016/s0891-5849(98)00334-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
It is unknown which of the reactive oxygen species is primarily responsible for the cytotoxicity of 95% O2 for rat distal fetal lung epithelial cells in vitro. Incubation of cells with 25 U/ml polyethylene glycol (PEG)-conjugated SOD and 50 U/ml PEG-catalase, but not PEG-SOD or SOD mimics alone, significantly reduced 95% O2-mediated cytotoxicity. Liposome-entrapped catalase, without SOD, also significantly reduced 95% O2-mediated cytotoxicity. Increased formation of lipid hydroperoxides, as assessed by the formation of 8-isoprostane and aldehydes, was attenuated by both 100 microM Trolox, a vitamin E analogue, and by 5 microM U74389G, an amino steroid. Trolox, but not U74389G, prevented an increase in cell-derived H2O2, hydroxyl radical and 95% O2-mediated cytotoxicity. An increase in hydroxyl radical formation, but not cell death, observed in 95% O2, was prevented by 0.1 microM phenanthrolene, a cell permeant iron chelator. DNA extracts of rat distal fetal lung epithelial cells maintained under serum-free conditions had an electrophoretic pattern consistent with some degree of apoptosis. However, no increase in laddering was seen with exposure to 95% O2. These data are consistent with hydrogen peroxide, but not lipid hydroperoxides or hydroxyl radical, being a critical effector of O2-mediated necrotic cell death in distal lung epithelial cells.
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Affiliation(s)
- X Luo
- Hospital for Sick Children Research Institute, Department of Paediatrics, University of Toronto, Ontario, Canada
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