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Creemers SG, Feelders RA, Valdes N, Ronchi CL, Volante M, van Hemel BM, Luconi M, Ettaieb MHT, Mannelli M, Chiara MD, Fassnacht M, Papotti M, Kerstens MN, Nesi G, Haak HR, van Kemenade FJ, Hofland LJ. The IGF2 methylation score for adrenocortical cancer: an ENSAT validation study. Endocr Relat Cancer 2020; 27:541-550. [PMID: 32668404 DOI: 10.1530/erc-19-0378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 11/08/2022]
Abstract
Adrenocortical carcinoma (ACC) is diagnosed using the histopathological Weiss score (WS), but remains clinically elusive unless it has metastasized or grows locally invasive. Previously, we proposed the objective IGF2 methylation score as diagnostic tool for ACC. This multicenter European cohort study validates these findings. Patient and tumor characteristics were obtained from adrenocortical tumor patients. DNA was isolated from frozen specimens, where after DMR2, CTCF3, and H19 were pyrosequenced. The predictive value of the methylation score for malignancy, defined by the WS or metastasis development, was assessed using receiver operating characteristic curves and logistic and Cox regression analyses. Seventy-six ACC patients and 118 patients with adrenocortical adenomas were included from seven centers. The methylation score and tumor size were independently associated with the pathological ACC diagnosis (OR 3.756 95% CI 2.224-6.343; OR 1.467 95% CI 1.202-1.792, respectively; Hosmer-Lemeshow test P = 0.903), with an area under the curve (AUC) of 0.957 (95% CI 0.930-0.984). The methylation score alone resulted in an AUC of 0.910 (95% CI 0.866-0.952). Cox regression analysis revealed that the methylation score, WS and tumor size predicted development of metastases in univariate analysis. In multivariate analysis, only the WS predicted development of metastasis (OR 1.682 95% CI 1.285-2.202; P < 0.001). In conclusion, we validated the high diagnostic accuracy of the IGF2 methylation score for diagnosing ACC in a multicenter European cohort study. Considering the known limitations of the WS, the objective IGF2 methylation score could potentially provide extra guidance on decisions on postoperative strategies in adrenocortical tumor patients.
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Affiliation(s)
- S G Creemers
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - R A Feelders
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - N Valdes
- Servicio de Endocrinología y Nutrición, Hospital Universitario de Asturias, Oviedo, Spain
| | - C L Ronchi
- Comprehensive Cancer Center Mainfranken, University of Würzburg, Würzburg, Germany
- Institute of Metabolism and System Research, University of Birmingham, Birmingham, UK
| | - M Volante
- Department of Oncology, University of Turin, Orbassano, Turin, Italy
| | - B M van Hemel
- Department of Pathology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - M Luconi
- Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy
| | - M H T Ettaieb
- Departments of Internal Medicine and Endocrinology, Máxima Medical Center, Eindhoven, The Netherlands
| | - M Mannelli
- Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, Florence, Italy
| | - M D Chiara
- Instituto Universitario de Oncologia del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain
| | - M Fassnacht
- Division of Endocrinology and Diabetes, Department of Internal Medicine, University Hospital, University of Würzburg, Würzburg, Germany
| | - M Papotti
- Department of Oncology, University of Turin, Orbassano, Turin, Italy
| | - M N Kerstens
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - G Nesi
- Division of Pathological Anatomy, University of Florence, Florence, Italy
| | - H R Haak
- Departments of Internal Medicine and Endocrinology, Máxima Medical Center, Eindhoven, The Netherlands
| | - F J van Kemenade
- Department of Pathology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - L J Hofland
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
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2
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Ajona D, Pajares MJ, Chiara MD, Rodrigo JP, Jantus-Lewintre E, Camps C, Suarez C, Bagán JV, Montuenga LM, Pio R. Complement activation product C4d in oral and oropharyngeal squamous cell carcinoma. Oral Dis 2015; 21:899-904. [DOI: 10.1111/odi.12363] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 06/23/2015] [Accepted: 07/26/2015] [Indexed: 02/05/2023]
Affiliation(s)
- D Ajona
- Program in Solid Tumors and Biomarkers; Center for Applied Medical Research (CIMA); Pamplona Spain
- Navarra's Health Research Institute (IDISNA); Pamplona Spain
| | - MJ Pajares
- Program in Solid Tumors and Biomarkers; Center for Applied Medical Research (CIMA); Pamplona Spain
- Navarra's Health Research Institute (IDISNA); Pamplona Spain
- Department of Histology and Pathology; School of Medicine; University of Navarra; Pamplona Spain
| | - MD Chiara
- Servicio de Otorrinolaringología; Hospital Universitario Central de Asturias; Instituto Universitario de Oncología del Principado de Asturias; Universidad de Oviedo; Oviedo Spain
| | - JP Rodrigo
- Servicio de Otorrinolaringología; Hospital Universitario Central de Asturias; Instituto Universitario de Oncología del Principado de Asturias; Universidad de Oviedo; Oviedo Spain
| | - E Jantus-Lewintre
- Molecular Oncology Laboratory; Fundación para la Investigación del Hospital General Universitario de Valencia; Valencia Spain
- Department of Biotechnology; Universitat Politècnica de Valencia; Valencia Spain
| | - C Camps
- Department of Medicine; University of Valencia; Valencia Spain
- Department of Medical Oncology; Hospital General Universitario de Valencia; Valencia Spain
| | - C Suarez
- Servicio de Otorrinolaringología; Hospital Universitario Central de Asturias; Instituto Universitario de Oncología del Principado de Asturias; Universidad de Oviedo; Oviedo Spain
| | - JV Bagán
- Department of Oral Medicine; University of Valencia, and Service of Stomatology and Maxillofacial Surgery; University General Hospital; Valencia Spain
| | - LM Montuenga
- Program in Solid Tumors and Biomarkers; Center for Applied Medical Research (CIMA); Pamplona Spain
- Navarra's Health Research Institute (IDISNA); Pamplona Spain
- Department of Histology and Pathology; School of Medicine; University of Navarra; Pamplona Spain
| | - R Pio
- Program in Solid Tumors and Biomarkers; Center for Applied Medical Research (CIMA); Pamplona Spain
- Navarra's Health Research Institute (IDISNA); Pamplona Spain
- Department of Biochemistry and Genetics; School of Sciences; University of Navarra; Pamplona Spain
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3
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Abstract
PURPOSE To develop a reliable animal model able to reproduce the behavior of head and neck squamous cell carcinomas (HNSCC). This model should facilitate our understanding of the molecular mechanisms of tumorigenicity and progression of these tumors, as well as the evaluation of novel therapies. MATERIAL AND METHODS 20 nude mice nu/nu were injected intraorally and submucosally with a cell line derived from a human squamous cell carcinoma of the glottis. RESULTS 90% of the mice developed locally agressive squamous cell carcinomas, invading the surrounding muscle fibers and into loose connective tissue structures. All the tumors showed perineural growth. Four (22%) of the 18 mice showed bone destruction, and 22% vascular invasion. Tumor cells invaded lymphatic vessels in all the specimens, and 100% of the mice developed regional lymph node metastases. None of the animals developed haematogenous metastases. CONCLUSIONS We present a metastasing model of HNSCC that resembles its human counterpart in many aspects.
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Affiliation(s)
- R Cabanillas
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias, Universidad de Oviedo, Instituto Universitario de Oncologia del Principado de Asturias, Oviedo.
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4
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Chiara MD, Monje F, Castellano A, López-Barneo J. A small domain in the N terminus of the regulatory alpha-subunit Kv2. 3 modulates Kv2.1 potassium channel gating. J Neurosci 1999; 19:6865-73. [PMID: 10436044 PMCID: PMC6782880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
Recent work has demonstrated the existence of regulatory K(+) channel alpha-subunits that are electrically silent but capable of forming heterotetramers with other pore-forming subunits to modify their function. We have investigated the molecular determinant of the modulatory effects of Kv2.3, a silent K(+) channel alpha-subunit specific of brain. This subunit induces on Kv2.1 channels a marked deceleration of activation, inactivation, and closing kinetics. We constructed chimeras of the Kv2.1 and Kv2.3 proteins and analyzed the K(+) currents resulting from the coexpression of the chimeras with Kv2.1. The data indicate that a region of 59 amino acids in the N terminus, adjacent to the first transmembrane segment, is the major structural element responsible for the regulatory function of Kv2.3. The sequence of this domain of Kv2.3 is highly divergent compared with the same region in the other channels of the Kv2 family. Replacement of the regulatory fragment of Kv2.3 by the equivalent of Kv2.1 leads to loss of modulatory function, whereas gain of modulatory function is observed when the Kv2.3 fragment is transferred to Kv2.1. Thus, this study identifies a N-terminus domain involved in Kv2.1 channel gating and in the modulation of this channel by a regulatory alpha-subunit.
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Affiliation(s)
- M D Chiara
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, E-41009 Sevilla, Spain
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5
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Reed R, Chiara MD. Identification of RNA-protein contacts within functional ribonucleoprotein complexes by RNA site-specific labeling and UV crosslinking. Methods 1999; 18:3-12. [PMID: 10208811 DOI: 10.1006/meth.1999.0751] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A variety of cellular processes are carried out by highly complex ribonucleoprotein (RNP) particles in which multiple RNA-RNA, RNA-protein, and protein-protein interactions occur. The spliceosome, which executes the nuclear pre-mRNA splicing reaction, is a particularly striking example of a complex RNP, containing a minimum of 50 distinct protein components as well as five small nuclear RNAs. In order to identify which among the numerous proteins may play critical roles in the splicing reaction, we have assembled spliceosomal complexes on pre-mRNA containing a single 32P-labeled nucleotide, isolated the complexes by gel filtration, and then carried out UV crosslinking. The combination of these three methods has allowed the identification of proteins that crosslink to critical sequence elements during each stage in spliceosome assembly. These methods should be generally applicable to the analysis of RNP complexes assembled in vitro.
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Affiliation(s)
- R Reed
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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6
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Abstract
The first AG dinucleotide downstream from the branchpoint sequence (BPS) is chosen as the 3' splice site during catalytic step II of the splicing reaction. The mechanism and factors involved in selection of this AG are not known. Early in mammalian spliceosome assembly, U2AF65 binds to the pyrimidine tract between the BPS and AG. Here we show that U2AF65 crosslinking is replaced by crosslinking of three proteins of 110, 116 and 220 kDa prior to catalytic step II, and we provide evidence that all three proteins are components of U5 snRNP. These proteins interact with pre-mRNA in the region spanning from immediately downstream of U2 snRNP's binding site at the BPS to just beyond the 3' splice site. We also demonstrate that there are strict constraints on both the sequence and the distance between the BPS and AG for catalytic step II. Together, these observations suggest that U5 snRNP is positioned on the 3' splice site by an interaction (direct or indirect) with U2 snRNP bound at the BPS and by a direct interaction with the pyrimidine tract. The functional AG for catalytic step II may be specified, in turn, by its location with respect to the U5 snRNP binding site.
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Affiliation(s)
- M D Chiara
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
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7
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Castellano A, Chiara MD, Mellström B, Molina A, Monje F, Naranjo JR, López-Barneo J. Identification and functional characterization of a K+ channel alpha-subunit with regulatory properties specific to brain. J Neurosci 1997; 17:4652-61. [PMID: 9169526 PMCID: PMC6573349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The physiological diversity of K+ channels mainly depends on the expression of several genes encoding different alpha-subunits. We have cloned a new K+ channel alpha-subunit (Kv2.3r) that is unable to form functional channels on its own but that has a major regulatory function. Kv2.3r can coassemble selectively with other alpha-subunits to form functional heteromultimeric K+ channels with kinetic properties that differ from those of the parent channels. Kv2.3r is expressed exclusively in the brain, being concentrated particularly in neocortical neurons. The functional expression of this regulatory alpha-subunit represents a novel mechanism without precedents in voltage-gated channels, which might contribute to further increase the functional diversity of K+ channels necessary to specify the intrinsic electrical properties of individual neurons.
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Affiliation(s)
- A Castellano
- Facultad de Medicina, Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, E-41009, Sevilla, Spain
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8
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Ramírez R, Bedoya FJ, Chiara MD, Sobrino F. Inhibitory effect of albumin-derived advanced glycosylation products on PMA-induced superoxide anion production by rat macrophages. Life Sci 1997; 60:2279-89. [PMID: 9194683 DOI: 10.1016/s0024-3205(97)00283-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Advanced glycosylation end products (AGE) are implicated in many of the complications of diabetes. In the same way, infectious diseases are frequently associated with this disease. An impaired respiratory burst in macrophages may be a cause of infectious complications in diabetic patients. To establish a possible mechanism of this altered cell function, we have analyzed the effect of AGE-modified proteins on PMA-dependent superoxide anion production (O2.-) from normal rat peritoneal macrophages. We have used AGE-modified bovine serum albumin (AGE-BSA) prepared by incubation with glucose. AGE-BSA partially inhibits the phorbol ester-dependent superoxide production by macrophages in vitro. The specificity of this inhibitory effect is demonstrated by the fact that aminoguanidine, an inhibitor of the formation of AGE products, fully prevents the effect of AGE-BSA in vitro. Macrophages from diabetic rats shown an inhibition on PMA dependent-O2.- production. However, the treatment in vivo with aminoguanidine produced a cancelation of the inhibitory effect observed in the diabetic state. These data suggest that AGE-modified proteins could be implicated in the impairment of macrophage respiratory burst in diabetes.
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Affiliation(s)
- R Ramírez
- Departamento de Bioquímica Médica y Biología Molecular, Universidad de Sevilla, Spain
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9
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Chiara MD, Gozani O, Bennett M, Champion-Arnaud P, Palandjian L, Reed R. Identification of proteins that interact with exon sequences, splice sites, and the branchpoint sequence during each stage of spliceosome assembly. Mol Cell Biol 1996; 16:3317-26. [PMID: 8668147 PMCID: PMC231326 DOI: 10.1128/mcb.16.7.3317] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We have carried out a systematic analysis of the proteins that interact with specific intron and exon sequences during each stage of mammalian spliceosome assembly. This was achieved by site-specifically labeling individual nucleotides within the 5' and 3' splice sites, the branchpoint sequence (BPS), or the exons with 32P and identifying UV-cross-linked proteins in the E, A, B, or C spliceosomal complex. Significantly, two members of the SR family of splicing factors, which are known to promote E-complex assembly, cross-link within exon sequences to a region approximately 25 nucleotides upstream from the 5' splice site. At the 5' splice site, cross-linking of the U5 small nuclear ribonucleoprotein particle protein, U5(200), was detected in both the B and C complexes. As observed in yeast cells, U5(200), also cross-links to intron/exon sequences at the 3' splice site in the C complex and may play a role in aligning the 5' and 3' exons for ligation. With label at the branch site, we detected three distinct proteins, designated BPS72,BpS70, and BPS56, which replace one another in the E, A, and C complexes. Another dynamic exchange was detected with pre-mRNA labeled at the AG dinucleotide of the 3' splice site. In this case, a protein, AG100,cross-links in the A complex and is replaced by another protein, AG75, in the C complex. The observation that these proteins are specifically associated with critical pre-mRNA sequence elements in functional complexes at different stages of spliceosome assembly implicates roles for these factors in key recognition events during the splicing pathway.
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Affiliation(s)
- M D Chiara
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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10
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Conde M, Chiara MD, Gracia Marquez M, Andrade J, Santa Maria C, Bedoya F, Sobrino F. Respiratory burst is decreased by human hyperlipemic serum in rat peritoneal macrophages. Free Radic Res 1996; 24:107-14. [PMID: 8845911 DOI: 10.3109/10715769609088006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effect of hyperlipemic human serum on superoxide anion (O2-) production by rat peritoneal macrophages was investigated. Phorbol myristate acetate (PMA)-stimulated O2- production was inhibited when cells were preincubated with hyperlipemic human serum. This inhibition was specifically carried out by a lipid fraction and was dependent on both cholesterol and triglyceride serum levels. This inhibitory effect was not exerted by a direct effect on NADPH-oxidase activity, nor by a putative superoxide dismutase activity present in the serum. With human neutrophils, we observed a decreased mobility of the cytosolic factor p47-phox to the membrane during the activation process, caused by hyperlipemic serum. We did not find any effect of hyperlipemic serum on NO2- production by cultured rat macrophages. These results suggest that a pathological increase of circulating plasma lipids may be associated with an impaired inflamatory capacity of macrophages.
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Affiliation(s)
- M Conde
- Dpto. Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain
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11
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Abstract
A fundamental question in the splicing of precursor messenger RNA is how the 5' and 3' splice sites are recognized and paired during the splicing reaction. It has been proposed that spliceosome assembly in metazoan pre-mRNAs can be initiated through interaction between the 3' splice site and specific sequence elements on the downstream exon (an exonic enhancer or a 5' splice site). Pairing of the intronic 5' and 3' splice sites occurs subsequently. We report here that 5' and 3' splice sites located on separate synthetic pre-mRNA substrates can be efficiently trans-spliced if the 3' trans-splicing substrate contains these downstream sequence elements. Moreover, selection of the trans 5' splice site can occur after the second pre-spliceosomal complex A has assembled on the 3' trans-splicing substrate. Thus our data demonstrate that 5' and 3' splice-site pairing in metazoans can occur in two distinct steps.
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Affiliation(s)
- M D Chiara
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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12
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Conde M, Chiara MD, Pintado E, Sobrino F. Modulation of phorbol ester-induced respiratory burst by vanadate, genistein, and phenylarsine oxide in mouse macrophages. Free Radic Biol Med 1995; 18:343-8. [PMID: 7744319 DOI: 10.1016/0891-5849(94)00126-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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: 01/26/2023]
Abstract
The effect of the inhibitors of tyrosine phosphatase (vanadate and phenylarsine oxide) and of an inhibitor of tyrosine kinase (genistein) on O2.- production in mouse peritoneal macrophages was examined. Vanadate and phenylarsine oxide produced a dose-dependent inhibition of phorbol myristate acetate (PMA)-induced O2.- production, whereas genistein potentiated O2.- production triggered by phorbol ester. Vanadate had no effect on the respiratory burst in human neutrophils challenged with fMLP, in agreement with previously published data on human intact neutrophils. It did not alter reduced nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase activity in membrane preparations of mouse peritoneal macrophages. These data suggest that the phosphorylation of protein(s) in tyrosine residues blocked the PMA-dependent respiratory burst in mouse macrophages.
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Affiliation(s)
- M Conde
- Departmento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain
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13
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Chiara MD, Champion-Arnaud P, Buvoli M, Nadal-Ginard B, Reed R. Specific protein-protein interactions between the essential mammalian spliceosome-associated proteins SAP 61 and SAP 114. Proc Natl Acad Sci U S A 1994; 91:6403-7. [PMID: 8022796 PMCID: PMC44210 DOI: 10.1073/pnas.91.14.6403] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Spliceosome-associated proteins (SAPs) 61, 62, and 114 can be UV-crosslinked to pre-mRNA in purified spliceosomal complexes and are associated with U2 small nuclear ribonucleoproteins (snRNP). These proteins also compose the essential heterotrimeric splicing factor SF3a, and products of yeast pre-mRNA processing genes PRP9, PRP11, and PRP21 are their likely yeast counterparts. We report the isolation of a cDNA encoding SAP 61 and find that it is 30% identical in amino acid sequence to PRP9. A C-terminal Cys2His2 zinc-finger-like motif, which could be involved in the pre-mRNA binding, is the most highly conserved region of the protein. We also demonstrate specific protein-protein interactions between SAPs 61 and 114 and show that the N terminus of SAP 61 is required for this interaction. Significantly, the corresponding proteins are also known to interact in yeast: PRP9 interacts with PRP21, and the N-terminal portion of PRP9 is required. Previous work showed that direct interactions also occur between SAPs 62 and 114 and between the corresponding PRPs 11 and 21. These observations indicate that the specific protein-protein interactions that occur between the three prespliceosomal factors have been conserved between yeast and mammals.
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Affiliation(s)
- M D Chiara
- Department of Cardiology, Children's Hospital, Boston, MA 02115
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14
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Andrés V, Chiara MD, Mahdavi V. A new bipartite DNA-binding domain: cooperative interaction between the cut repeat and homeo domain of the cut homeo proteins. Genes Dev 1994; 8:245-57. [PMID: 7905452 DOI: 10.1101/gad.8.2.245] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The recently cloned Clox (Cut-like homeo box) and CDP (CCAAT displacement protein), two mammalian counterparts of the Drosophila Cut homeo protein, correspond to alternatively spliced products of the same gene (mClox, for mammalian Cut-like homeo box). Although these proteins reportedly bind to apparently unrelated DNA sequences, we show by in vitro selection of optimal binding sites that both Clox and CDP have the same preferred DNA-binding specificity. The palindromic consensus target sequence, 5'-(t/a)(a/t)tATCGATTAt(t/c)(t/g)(t/a)-3', contains a bona fide homeo domain binding motif (ATTA). In addition, 37% of the in vitro-selected sequences have a CCAAT box, the canonical target for members of the family of CCAAT-binding factors. A characteristic feature of the cut homeo proteins is the presence of three evolutionarily conserved 73-amino-acid repeats of unknown function, the so-called cut repeats. We present evidence that the cut repeat II binds to mClox consensus targets independently of the DNA-binding activity of the homeo domain. In vitro selection of binding sites shows that the optimal targets for the cut repeat II contain one or more CCAAT boxes and, like the homeo domain, an ATTA core. These results indicate that the DNA-binding activity of the second cut repeat can account for the suggested role of CDP mClox as CCAAT displacement protein, a putative repressor of gene expression. We also report that the mClox homeo domain and cut repeat II interact in vitro in the absence of DNA. This interaction, which greatly enhances the DNA-binding activity of the binary complex, is specific to the cut homeo proteins. No cooperativity was observed between the cut repeat II and the homeo domains of Oct-1 and Gtx. Furthermore, the Drosophila cut repeat II, which does not appear to bind to DNA, also enhances the DNA-binding activity of the mClox homeo domain. Thus, the bifunctional cut repeat II, which defines a new family of bipartite DNA-binding proteins, is likely to play an important role in the function of the cut homeo proteins.
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Affiliation(s)
- V Andrés
- Department of Cardiology, Children's Hospital, Boston, Massachusetts 02115
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15
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Chiara MD, Sobrino F. Beta-naphthylamine induces anion superoxide production in rat peritoneal macrophages. Biochem Pharmacol 1992; 43:1841-5. [PMID: 1315548 DOI: 10.1016/0006-2952(92)90719-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Rat peritoneal macrophages were incubated in the presence of beta-naphthylamine (beta-NA), a well known carcinogenic agent, and some parameters of respiratory burst were studied. beta-NA induced a time- and dose-dependent stimulation of superoxide anion (O-2) production, and this enhancement was suppressed by the addition of superoxide dismutase enzyme. Also, no cooperative effect between beta-NA and phorbol 12-myristate 13-acetate was observed. Other observations were as follows: (i) the simultaneous presence of polymyxin B, and staurosporine inhibitors of protein kinase C, inhibited beta-NA-dependent O-2 production; (ii) NADPH-oxidase contained in postnuclear fraction from beta-NA-incubated macrophages showed a greater activity than control fractions; (iii) the stimulation of O-2 production elicited by beta-NA was several-fold enhanced in activated macrophages compared to resident cells. These data suggest that beta-NA produces the activation of NADPH-oxidase through protein kinase C.
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Affiliation(s)
- M D Chiara
- Departamento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain
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16
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Chiara MD, Sobrino F. Modulation of the inhibition of respiratory burst in mouse macrophages by cyclosporin A: effect of in vivo treatment, glucocorticoids and the state of activation of cells. Immunol Suppl 1991; 72:133-7. [PMID: 1847692 PMCID: PMC1384349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cyclosporin A (CsA) is an immunosuppressor without myelotoxicity. It is thought that its effect is mediated by inhibition of Interleukin-2 (IL-2) receptor expression in lymphocytes. We have recently described that CsA reduces phorbol 12-myristate 13-acetate (PMA)-dependent superoxide anion and H2O2 production by resident mice macrophages in vitro. The present work provides evidence that the capacity of CsA to produce this inhibition is abolished when macrophages are in the activated state. We also show that peritoneal macrophages from CsA-treated mice retain the capacity to inhibit O2- production. The interaction between CsA and glucocorticoids in vitro shows a co-operative effect between both agents. These studies demonstrate a novel action of CsA related to its modulation of the inhibition of the respiratory burst. The physiological role of these CsA effects and modulation need further exploration.
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Affiliation(s)
- M D Chiara
- Departamento de Bioquimica Médica y Biologia Molecular, Facultad de Medicina, Universidad de Sevilla, Spain
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Chiara MD, Bedoya F, Sobrino F. Cyclosporin A inhibits phorbol ester-induced activation of superoxide production in resident mouse peritoneal macrophages. Biochem J 1989; 264:21-6. [PMID: 2557828 PMCID: PMC1133542 DOI: 10.1042/bj2640021] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Peritoneal resident macrophages from mice are sensitive to inhibition by cyclosporin A (CsA) of phorbol 12-myristate 13-acetate (PMA)-stimulated oxidative burst. Inhibition was assessed in terms of superoxide anion (O2.-) and H2O2 production. Key findings were as follows. (a) CsA inhibited in a dose-dependent manner the production of O2.- when cells were stimulated with PMA. CsA did not alter the respiratory burst induced by other stimuli (zymosan, concanavalin A and fMet-Leu-Phe). It was verified that CsA itself had no scavenger effect. (b) A concomitant decrease in H2O2 liberation following CsA exposure was found. This inhibition was observed both in the initial rate of synthesis and in the accumulation after 15 min of incubation. (c) NADPH oxidase activity in the crude supernatant was unaffected by the previous incubation of macrophages with CsA. CsA does not inhibit glucose transport measured as 14CO2 production. (d) The production of O2.- was strongly dependent on the glucose concentration. Sodium oleate also stimulated O2.- production in resident macrophages. These data might be correlated with the inhibitory effect of CsA upon other functions of macrophages.
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Affiliation(s)
- M D Chiara
- Departamento de Bioquímica Medica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain
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