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Chianese G, Golin-Pacheco SD, Taglialatela-Scafati O, Collado JA, Munoz E, Appendino G, Pollastro F. Bioactive triterpenoids from the caffeine-rich plants guayusa and maté. Food Res Int 2019; 115:504-510. [PMID: 30599971 DOI: 10.1016/j.foodres.2018.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/17/2018] [Accepted: 10/01/2018] [Indexed: 01/23/2023]
Abstract
Unlike all other caffeinated plants, guayusa (Ilex guayusa Loes.) and maté (Ilex paraguariensis A. St. Hill) contain high amounts of pentacyclic triterpenoid acids and alcohols. A phytochemical investigation on these plants revealed a similar triterpenoid profile and a content of ursolic acid (0.7-1%) and amyrin esters (up to 0.5%), quite unusual for dietary plants. The major constituent of the amyrin complex from both plants is α-amyrin palmitate (2a), accompanied by lower amounts of its corresponding palmitoleate (2b) and by the corresponding constitutional isomers from the β-series (3a and 3b, respectively). Ursolic acid (1) was identified as the responsible for the activity of maté and guayusa extracts in the activation of TGR5, a nuclear receptor of relevance for the prevention and management of diabetes and metabolic syndrome because of its involvement in the regulation of energy expenditure and insulin sensitivity.
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Affiliation(s)
- G Chianese
- University of Naples Federico II, Department of Pharmacy, School of Medicine and Surgery, Naples, Italy
| | | | - O Taglialatela-Scafati
- University of Naples Federico II, Department of Pharmacy, School of Medicine and Surgery, Naples, Italy.
| | - J A Collado
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain.; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain; Hospital Universitario Reina Sofía, Córdoba, Spain
| | - E Munoz
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain.; Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba, Córdoba, Spain; Hospital Universitario Reina Sofía, Córdoba, Spain
| | - G Appendino
- Department of Pharmaceutical Sciences, University of Eastern Piedmont, Novara, Italy
| | - F Pollastro
- Department of Pharmaceutical Sciences, University of Eastern Piedmont, Novara, Italy.
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Marquina M, Collado JA, Pérez-Cruz M, Fernández-Pernas P, Fafián-Labora J, Blanco FJ, Máñez R, Arufe MC, Costa C. Biodistribution and Immunogenicity of Allogeneic Mesenchymal Stem Cells in a Rat Model of Intraarticular Chondrocyte Xenotransplantation. Front Immunol 2017; 8:1465. [PMID: 29163532 PMCID: PMC5681521 DOI: 10.3389/fimmu.2017.01465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/19/2017] [Indexed: 02/05/2023] Open
Abstract
Xenogeneic chondrocytes and allogeneic mesenchymal stem cells (MSC) are considered a potential source of cells for articular cartilage repair. We here assessed the immune response triggered by xenogeneic chondrocytes when injected intraarticularly, as well as the immunoregulatory effect of allogeneic bone marrow-derived MSC after systemic administration. To this end, a discordant xenotransplantation model was established by injecting three million porcine articular chondrocytes (PAC) into the femorotibial joint of Lewis rats and monitoring the immune response. First, the fate of MSC injected using various routes was monitored in an in vivo imaging system. The biodistribution revealed a dependency on the injection route with MSC injected intravenously (i.v.) succumbing early after 24 h and MSC injected intraperitoneally (i.p.) lasting locally for at least 5 days. Importantly, no migration of MSC to the joint was detected in rats previously injected with PAC. MSC were then administered either i.v. 1 week before PAC injection or i.p. 3 weeks after to assess their immunomodulatory function on humoral and adaptive immune parameters. Anti-PAC IgM and IgG responses were detected in all PAC-injected rats with a peak at week 2 postinjection and reactivity remaining above baseline levels by week 18. IgG2a and IgG2b were the predominant and long-lasting IgG subtypes. By contrast, no anti-MSC antibody response was detected in the cohort injected with MSC only, but infusion of MSC before PAC injection temporarily augmented the anti-PAC antibody response. Consistent with a cellular immune response to PAC in PAC-injected rats, cytokine/chemokine profiling in serum by antibody array revealed a distinct pattern relative to controls characterized by elevation of multiple markers at week 2, as well as increases in proliferation in draining lymph nodes. Notably, systemic administration of allogeneic MSC under the described conditions did not diminish the immune response. IL-2 measurements in cocultures of rat peripheral blood lymphocytes with PAC indicated that PAC injection induced some T-cell hyporesponsiveness that was not enhanced in the cohorts additionally receiving MSC. Thus, PAC injected intraarticularly in Lewis rats induced a cellular and humoral immune response that was not counteracted by the systemic administration of allogeneic MSC under the described conditions.
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Affiliation(s)
- Maribel Marquina
- Infectious Diseases and Transplantation Division, Institut d’Investigació Biomèdica de Bellvitge – IDIBELL, Bellvitge University Hospital, ICS, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Javier A. Collado
- Infectious Diseases and Transplantation Division, Institut d’Investigació Biomèdica de Bellvitge – IDIBELL, Bellvitge University Hospital, ICS, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Magdiel Pérez-Cruz
- Infectious Diseases and Transplantation Division, Institut d’Investigació Biomèdica de Bellvitge – IDIBELL, Bellvitge University Hospital, ICS, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Pablo Fernández-Pernas
- Cellular Therapy and Medicine Regenerative Group, Department of Medicine, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC), Sergas, Universidade da Coruña, As Xubias, A Coruña, Spain
| | - Juan Fafián-Labora
- Cellular Therapy and Medicine Regenerative Group, Department of Medicine, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC), Sergas, Universidade da Coruña, As Xubias, A Coruña, Spain
| | - Francisco J. Blanco
- Grupo de Proteómica-ProteoRed/Plataforma PBR2-ISCIII, Servicio de Reumatología, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC), Sergas, Universidade da Coruña, As Xubias, A Coruña, Spain
| | - Rafael Máñez
- Infectious Diseases and Transplantation Division, Institut d’Investigació Biomèdica de Bellvitge – IDIBELL, Bellvitge University Hospital, ICS, L’Hospitalet de Llobregat, Barcelona, Spain
| | - María C. Arufe
- Cellular Therapy and Medicine Regenerative Group, Department of Medicine, Instituto de Investigación Biomédica de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC), Sergas, Universidade da Coruña, As Xubias, A Coruña, Spain
| | - Cristina Costa
- Infectious Diseases and Transplantation Division, Institut d’Investigació Biomèdica de Bellvitge – IDIBELL, Bellvitge University Hospital, ICS, L’Hospitalet de Llobregat, Barcelona, Spain
- *Correspondence: Cristina Costa,
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Alvarez I, Collado JA, Colobran R, Carrascal M, Ciudad MT, Canals F, James EA, Kwok WW, Gärtner M, Kyewski B, Pujol-Borrell R, Jaraquemada D. Central T cell tolerance: Identification of tissue-restricted autoantigens in the thymus HLA-DR peptidome. J Autoimmun 2015; 60:12-9. [PMID: 25911201 DOI: 10.1016/j.jaut.2015.03.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/12/2015] [Accepted: 03/18/2015] [Indexed: 11/22/2022]
Abstract
Promiscuous gene expression (pGE) of tissue-restricted self-antigens (TRA) in medullary thymic epithelial cells (mTECs) is in part driven by the Autoimmune Regulator gene (AIRE) and essential for self-tolerance. The link between AIRE functional mutations and multi-organ autoimmunity in human and mouse supports the role of pGE. Deep sequencing of the transcriptome revealed that mouse mTECs potentially transcribe an unprecedented range of >90% of all genes. Yet, it remains unclear to which extent these low-level transcripts are actually translated into proteins, processed and presented by thymic APCs to induce tolerance. To address this, we analyzed the HLA-DR-associated thymus peptidome. Within a large panel of peptides from abundant proteins, two TRA peptides were identified: prostate-specific semenogelin-1 (an autoantigen in autoimmune chronic prostatitis/chronic pelvic pain syndrome) and central nervous system-specific contactin-2 (an autoantigen in multiple sclerosis). Thymus expression of both genes was restricted to mTECs. SEMG1 expression was confined to mature HLA-DR(hi) mTECs of male and female donors and was AIRE-dependent, whereas CNTN2 was apparently AIRE-independent and was expressed by both populations of mTECs. Our findings establish a link between pGE, MHC-II peptide presentation and autoimmunity for bona fide human TRAs.
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Affiliation(s)
- Iñaki Alvarez
- Immunology Unit, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Javier A Collado
- Immunology Unit, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Roger Colobran
- Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Institut de Recerca (VHIR), Passeig Vall d'Hebron 119-129, 08023 Barcelona, Spain
| | - Montserrat Carrascal
- CSIC/UAB Proteomics Laboratory, IIBB-CSIC, IDIBAPS, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - M Teresa Ciudad
- Immunology Unit, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Françesc Canals
- Proteomics Laboratory, Medical Oncology Research Program, Vall d'Hebron Institut de Recerca, Barcelona, Spain
| | - Eddie A James
- Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - William W Kwok
- Benaroya Research Institute at Virginia Mason, Seattle, WA, USA
| | - Martina Gärtner
- Division of Developmental Immunology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Bruno Kyewski
- Division of Developmental Immunology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Ricardo Pujol-Borrell
- Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Vall d'Hebron Institut de Recerca (VHIR), Passeig Vall d'Hebron 119-129, 08023 Barcelona, Spain
| | - Dolores Jaraquemada
- Immunology Unit, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain; Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain.
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Collado JA, Guitart C, Ciudad MT, Alvarez I, Jaraquemada D. The Repertoires of Peptides Presented by MHC-II in the Thymus and in Peripheral Tissue: A Clue for Autoimmunity? Front Immunol 2013; 4:442. [PMID: 24381570 PMCID: PMC3865459 DOI: 10.3389/fimmu.2013.00442] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 11/26/2013] [Indexed: 11/13/2022] Open
Abstract
T-cell tolerance to self-antigens is established in the thymus through the recognition by developing thymocytes of self-peptide-MHC complexes and induced and maintained in the periphery. Efficient negative selection of auto-reactive T cells in the thymus is dependent on the in situ expression of both ubiquitous and tissue-restricted self-antigens and on the presentation of derived peptides. Weak or inadequate intrathymic expression of self-antigens increases the risk to generate an autoimmune-prone T-cell repertoire. Indeed, even small changes of self-antigen expression in the thymus affect negative selection and increase the predisposition to autoimmunity. Together with other mechanisms, tolerance is maintained in the peripheral lymphoid organs via the recognition by mature T cells of a similar set of self-peptides in homeostatic conditions. However, non-lymphoid peripheral tissue, where organ-specific autoimmunity takes place, often have differential functional processes that may lead to the generation of epitopes that are absent or non-presented in the thymus. These putative differences between peptides presented by MHC molecules in the thymus and in peripheral tissues might be a major key to the initiation and maintenance of autoimmune conditions.
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Affiliation(s)
- Javier A Collado
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Carolina Guitart
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - M Teresa Ciudad
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Iñaki Alvarez
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Dolores Jaraquemada
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
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Espinosa G, Collado JA, Scholz E, Mestre-Ferrer A, Kuse N, Takiguchi M, Carrascal M, Canals F, Pujol-Borrell R, Jaraquemada D, Alvarez I. Peptides presented by HLA class I molecules in the human thymus. J Proteomics 2013; 94:23-36. [PMID: 24029068 DOI: 10.1016/j.jprot.2013.08.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/26/2013] [Accepted: 08/28/2013] [Indexed: 12/31/2022]
Abstract
UNLABELLED The thymus is the organ in which T lymphocytes mature. Thymocytes undergo exhaustive selection processes that require interactions between the TCRs and peptide-HLA complexes on thymus antigen-presenting cells. The thymic peptide repertoire associated with HLA molecules must mirror the peptidome that mature T cells will encounter at the periphery, including peptides that arise from tissue-restricted antigens. The transcriptome of specific thymus cell populations has been widely studied, but there are no data on the HLA-I peptidome of the human thymus. Here, we describe the HLA-I-bound peptide repertoire from thymus samples, showing that it is mostly composed of high-affinity ligands from cytosolic and nuclear proteins. Several proteins generated more than one peptide, and some redundant peptides were found in different samples, suggesting the existence of antigen immunodominance during the processes that lead to central tolerance. Three HLA-I ligands were found to be derived from proteins expressed by stromal cells, including one from the protein TBATA (or SPATIAL), which is present in the thymus, brain and testis. The expression of TBATA in medullary thymic epithelial cells has been reported to be AIRE dependent. Thus, this report describes the first identification of a thymus HLA-I natural ligand derived from an AIRE-dependent protein with restricted tissue expression. BIOLOGICAL SIGNIFICANCE We present the first description of the HLA-I-bound peptide repertoire from ex vivo thymus samples. This repertoire is composed of standard ligands from cytosolic and nuclear proteins. Some peptides seem to be dominantly presented to thymocytes in the thymus. Most importantly, some HLA-I associated ligands derived from proteins expressed by stromal cells, including one peptide, restricted by HLA-A*31:01, arising from an AIRE-dependent protein with restricted tissue expression.
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Affiliation(s)
- Gabriel Espinosa
- Immunology Unit, Department of Cell Biology, Physiology and Immunology and Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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Collado JA, Alvarez I, Ciudad MT, Espinosa G, Canals F, Pujol-Borrell R, Carrascal M, Abian J, Jaraquemada D. Composition of the HLA-DR-associated human thymus peptidome. Eur J Immunol 2013; 43:2273-82. [PMID: 23719902 DOI: 10.1002/eji.201243280] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 04/17/2013] [Accepted: 05/27/2013] [Indexed: 11/05/2022]
Abstract
Major histocompatibility complex class II (MHC-II) molecules bind to and display antigenic peptides on the surface of antigen-presenting cells (APCs). In the absence of infection, MHC-II molecules on APCs present self-peptides and interact with CD4(+) T cells to maintain tolerance and homeostasis. In the thymus, self-peptides bind to MHC-II molecules expressed by defined populations of APCs specialised for the different steps of T-cell selection. Cortical epithelial cells present peptides for positive selection, whereas medullary epithelial cells and dendritic cells are responsible for peptide presentation for negative selection. However, few data are available on the peptides presented by MHC molecules in the thymus. Here, we apply mass spectrometry to analyse and identify MHC-II-associated peptides from five fresh human thymus samples. The data show a diverse self-peptide repertoire, mostly consisting of predicted MHC-II high binders. Despite technical limitations preventing single cell population analyses of peptides, these data constitute the first direct assessment of the HLA-II-bound peptidome and provide insight into how this peptidome is generated and how it drives T-cell repertoire formation.
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Affiliation(s)
- Javier A Collado
- Immunology Unit, Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Biologia Cel·lular, Fisiologia i Immunologia (BCFI), Universitat Autònoma de Barcelona, Barcelona, Spain
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Muixí L, Contreras V, Collado JA, Alexandre Y, Ballingall K, Bonneau M, Jaraquemada D, Schwartz-Cornil I. Unraveling features of the natural MHC class II peptidome of skin-migrated dendritic cells. Int Immunol 2011; 24:59-69. [PMID: 22194283 DOI: 10.1093/intimm/dxr096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dendritic cells (DCs) migrating from peripheral tissues at steady state are considered the most efficient antigen-presenting cells (APCs) involved in the induction of peripheral T-cell tolerance via self-antigen presentation on MHC class II molecules. However, difficulties in obtaining sufficient numbers of such DCs have precluded previous analyses of their natural MHC class II peptidome in laboratory animals or humans. Here, we overcome this difficulty by collecting the large quantities of sheep DCs that migrate from the skin via the afferent lymphatics at steady state to the draining lymph node. We compared the repertoire of MHC class II-bound peptides from afferent lymph DCs with autologous APCs derived from peripheral blood. A large fraction of the MHC class II peptidome from skin DCs was derived from membrane-recycling proteins (59%) and from proteins of the antigen presentation machinery (50%), whereas these types of peptides constituted a more limited fraction in blood APCs (21 and 11%, respectively). One sheep cytokeratin peptide was identified in the skin DC peptidome indicating active processing of epithelium-derived antigens. Conversely, peptides derived from cytosolic and soluble antigens of the extracellular milieu were more represented in blood APCs than skin DCs. The biased peptidome of skin-migrated DCs indicates that these cells express a peptide repertoire for the generation of self-reactive and/or regulatory T cells mainly directed toward DC molecules from internal and external membranes and to a lesser extent toward antigens of the extracellular milieu, including some tissue-specific peptides.
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Affiliation(s)
- Laia Muixí
- Immunology Unit, Institut de Biotecnologia i Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
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Muntané J, González R, Ranchal I, Collado JA, López-Sánchez LM, Herencia C, Rodríguez-Ariza A, Rafael Muñoz-Castañeda JR, de la Mata M. [Mechanisms of liver cell injury]. Rev Esp Enferm Dig 2007; 99:405-10. [PMID: 17973585 DOI: 10.4321/s1130-01082007000700007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- J Muntané
- Liver Research Unit, Reina Sofía University Hospital, Ciberehd, Córdoba, Spain.
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Lozano JM, Collado JA, Medina T, Muntané J. Protection against liver injury by PGE1 or anti-TNF-alpha is associated with a reduction of TNF-R1 expression in hepatocytes. Scand J Gastroenterol 2003; 38:1169-75. [PMID: 14686721 DOI: 10.1080/00365520310006063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Tumour necrosis factor-alpha (TNF-5) has been shown to exacerbate or protect against liver injury in different experimental models. In a previous study, we observed that enhancement of TNF-alpha expression in hepatocytes by prostaglandin E1 (PGE1) pre-administration induced iNOS expression and cytoprotection against experimental liver injury in rats. Nevertheless, the reduction of TNF-alpha bioactivity by anti-TNF-alpha antibodies also reduced liver injury by D-GalN. The purpose of the present study was to evaluate whether protection by PGE1 or anti-TNF-alpha was related to a common effect on the membrane-bound TNF-alpha receptor expression. METHODS Liver injury was induced in male Wistar rats by intraperitoneal injection of D-galactosamine (D-GalN) (1 g/kg). PGE1 or anti-TNF-alpha was administered at 30 or 60 min before D-GalN, respectively. Liver injury was evaluated by alanine aminotransferase (ALT) activity in serum and histological examination in liver sections. TNF-alpha was determined by ELISA in serum. The expression of TNF-alpha receptor type 1 (TNF-R1) and TNF-alpha receptor type 2 (TNF-R2) in hepatocytes was assessed by immunohistochemistry and immunoprecipitation + Western-blot analysis. RESULTS PGE1 or anti-TNF-alpha reduced liver injury induced by D-GalN. Although PGE1 enhanced and anti-TNF-alpha reduced TNF-alpha concentration in serum, both protective treatments reduced the expression of TNF-R1 in hepatocytes. TNF-R2 was not detected in our experimental conditions. CONCLUSIONS Our study showed that reduction of liver injury by PGE1 or anti-TNF-alpha antibodies was related to a reduction of TNF-R1 expression in hepatocytes.
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Affiliation(s)
- J M Lozano
- Unidad Clínica Aparato Digestivo, Servicio Anatomía Patológica, Hospital Universitario Reina Sofía, Av Menéndez Pidal s/n, Córdoba, Spain
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García-Porrero JA, Collado JA, Ojeda JL. Cell death during detachment of the lens rudiment from ectoderm in the chick embryo. Anat Rec (Hoboken) 1979; 193:791-804. [PMID: 426306 DOI: 10.1002/ar.1091930404] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The distribution and cytological characters of physiological cell death associated with formation of the lens vesicle in the chick embryo was studied by means of vital staining, light and electron microscopy. We have established a constant pattern of cell death which differs in some aspects from that reported for mammals and amphibians. The necrotic process is observed initially in the dorsal part of the lens cup (stage 15). The necrotic area progressively surrounds the lens pore as invagination proceeds (stage 16) and at stage 17 is located in the zone of fusion of the invaginated lens. After detachment of the lens (stages 18, 19 and 20) dead cells appear in the ectoderm, in the superficial epithelium of the lens vesicle and in the space between both structures. Ultrastructurally we observe isolated dead cells in different stages of degeneration and in phagocytosed cells. Phagocytosis is carried out by the neighboring healthy epithelial cells. Phagocytic activity was detected concomitant with the beginning of the necrotic process. Cell fragments were occasionally detected within the lens cavity.
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