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Santamaría B, Benito-Martin A, Ucero AC, Aroeira LS, Reyero A, Vicent MJ, Orzáez M, Celdrán A, Esteban J, Selgas R, Ruíz-Ortega M, Cabrera ML, Egido J, Pérez-Payá E, Ortiz A. A nanoconjugate Apaf-1 inhibitor protects mesothelial cells from cytokine-induced injury. PLoS One 2009; 4:e6634. [PMID: 19675677 PMCID: PMC2722088 DOI: 10.1371/journal.pone.0006634] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 06/23/2009] [Indexed: 01/22/2023] Open
Abstract
Background Inflammation may lead to tissue injury. We have studied the modulation of inflammatory milieu-induced tissue injury, as exemplified by the mesothelium. Peritoneal dialysis is complicated by peritonitis episodes that cause loss of mesothelium. Proinflammatory cytokines are increased in the peritoneal cavity during peritonitis episodes. However there is scarce information on the modulation of cell death by combinations of cytokines and on the therapeutic targets to prevent desmesothelization. Methodology Human mesothelial cells were cultured from effluents of stable peritoneal dialysis patients and from omentum of non-dialysis patients. Mesothelial cell death was studied in mice with S. aureus peritonitis and in mice injected with tumor necrosis factor alpha and interferon gamma. Tumor necrosis factor alpha and interferon gamma alone do not induce apoptosis in cultured mesothelial cells. By contrast, the cytokine combination increased the rate of apoptosis 2 to 3-fold over control. Cell death was associated with the activation of caspases and a pancaspase inhibitor prevented apoptosis. Specific caspase-8 and caspase-3 inhibitors were similarly effective. Co-incubation with both cytokines also impaired mesothelial wound healing in an in vitro model. However, inhibition of caspases did not improve wound healing and even impaired the long-term recovery from injury. By contrast, a polymeric nanoconjugate Apaf-1 inhibitor protected from apoptosis and allowed wound healing and long-term recovery. The Apaf-1 inhibitor also protected mesothelial cells from inflammation-induced injury in vivo in mice. Conclusion Cooperation between tumor necrosis factor alpha and interferon gamma contributes to mesothelial injury and impairs the regenerative capacity of the monolayer. Caspase inhibition attenuates mesothelial cell apoptosis but does not facilitate regeneration. A drug targeting Apaf-1 allows protection from apoptosis as well as regeneration in the course of inflammation-induced tissue injury.
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Affiliation(s)
- Beatriz Santamaría
- Dialysis Unit, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Instituto Reina Sofía de Investigación Nefrológica, Madrid, Spain
| | - Alberto Benito-Martin
- Dialysis Unit, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Instituto Reina Sofía de Investigación Nefrológica, Madrid, Spain
| | - Alvaro Conrado Ucero
- Dialysis Unit, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Instituto Reina Sofía de Investigación Nefrológica, Madrid, Spain
| | | | - Ana Reyero
- Dialysis Unit, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Instituto Reina Sofía de Investigación Nefrológica, Madrid, Spain
| | - María Jesús Vicent
- Polymer Therapeutics Laboratory, Department of Medicinal Chemistry, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Mar Orzáez
- Peptide and Protein Laboratory, Department of Medicinal Chemistry, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Angel Celdrán
- Dialysis Unit, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Instituto Reina Sofía de Investigación Nefrológica, Madrid, Spain
| | - Jaime Esteban
- Servicio de Microbiología, Fundación Jimenez Díaz, Madrid, Spain
| | - Rafael Selgas
- Servicio de Nefrología, Hospital Universitario La Paz, Madrid, Spain
| | - Marta Ruíz-Ortega
- Laboratory of Renal and Vascular Research, Universidad Autónoma de Madrid, Madrid, Spain
| | - Manuel López Cabrera
- Molecular Biology Department, Hospital Universitario de la Princesa, Madrid, Spain
| | - Jesús Egido
- Laboratory of Renal and Vascular Research, Universidad Autónoma de Madrid, Madrid, Spain
| | - Enrique Pérez-Payá
- Peptide and Protein Laboratory, Department of Medicinal Chemistry, Centro de Investigación Príncipe Felipe, Valencia, Spain
- Instituto de Biomedicina de Valencia CSIC, Valencia, Spain
| | - Alberto Ortiz
- Dialysis Unit, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Instituto Reina Sofía de Investigación Nefrológica, Madrid, Spain
- * E-mail:
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152
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Knecht E, Aguado C, Cárcel J, Esteban I, Esteve JM, Ghislat G, Moruno JF, Vidal JM, Sáez R. Intracellular protein degradation in mammalian cells: recent developments. Cell Mol Life Sci 2009; 66:2427-43. [PMID: 19399586 PMCID: PMC11115841 DOI: 10.1007/s00018-009-0030-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 04/02/2009] [Indexed: 12/16/2022]
Abstract
In higher organisms, dietary proteins are broken down into amino acids within the digestive tract but outside the cells, which incorporate the resulting amino acids into their metabolism. However, under certain conditions, an organism loses more nitrogen than is assimilated in the diet. This additional loss was found in the past century to come from intracellular proteins and started an intensive research that produced an enormous expansion of the field and a dispersed literature. Therefore, our purpose is to provide an updated summary of the current knowledge on the proteolytic machinery involved in intracellular protein degradation and its physiological and pathological relevance, especially addressed to newcomers in the field who may find further details in more specialized reviews. However, even providing a general overview, this is an extremely wide field and, therefore, we mainly focus on mammalian cells, while other cells will be mentioned only for comparison purposes.
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Affiliation(s)
- Erwin Knecht
- Centro de Investigación Príncipe Felipe, Valencia, Spain.
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153
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Abstract
Abstract
The germinal center (GC) is a transient lymphoid tissue microenvironment that fosters T cell–dependent humoral immunity. Within the GC, the B cell–specific enzyme, activation-induced cytidine deaminase (AID), mutates the immunoglobulin locus, thereby altering binding affinity for antigen. In the absence of AID, larger GC structures are observed in both humans and mice, but the reason for this phenomenon is unclear. Because significant apoptosis occurs within the GC niche to cull cells that have acquired nonproductive mutations, we have examined whether a defect in apoptosis could account for the larger GC structures in the absence of AID. In this report, we reveal significantly reduced death of B cells in AID−/− mice as well as in B cells derived from AID−/− bone marrow in mixed bone marrow chimeric mice. Furthermore, AID-expressing B cells show decreased proliferation and survival compared with AID−/− B cells, indicating an AID-mediated effect on cellular viability. The GC is an etiologic site for B-cell autoimmunity and lymphomagenesis, both of which have been linked to aberrant AID activity. We report a link between AID-induced DNA damage and B-cell apoptosis that has implications for the development of B-cell disorders.
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155
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Abstract
Apoptosis appears to be a carefully orchestrated process for the ordered dismantling of cells. A recent paper in BMC Developmental Biology shows that the disassembly of adherens junctions during apoptosis in Drosophila is progressive and requires the amino-terminal cleavage of the β-catenin Armadillo by the apoptotic effector caspase DrICE.
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Affiliation(s)
- Magali Suzanne
- The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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