Matrin 3 as a key regulator of endothelial cell survival.
ABSTRACT Matrin 3 is an integral component of nuclear matrix architecture that has been implicated in interacting with other nuclear proteins and thus modulating the activity of proximal promoters. In this study, we evaluated the contribution of this protein to proliferation of endothelial cells. To selectively modulate matrin 3 expression, we used siRNA oligonucleotides and transfection of cells with a pEGFP-N1-Mtr3. Our data indicate that downregulation of matrin 3 is responsible for reduced proliferation and leads to necrosis of endothelial cells. This conclusion is supported by observations that reducing matrin 3 expression results in (a) producing signs of necrosis detected by PI staining, LDH release, and scatter parameters in flow cytometry, (b) affecting cell cycle progression. It does not cause (c) membrane asymmetry of cells as indicated by lack of Annexin V binding as well as (d) activation of caspase 3 and cleavage of PARP. We conclude that matrin 3 plays a significant role in controlling cell growth and proliferation, probably via formation of complexes with nuclear proteins that modulate pro- and antiapoptotic signaling pathways. Thus, degradation of matrin 3 may be a switching event that induces a shift from apoptotic to necrotic death of cells.
- SourceAvailable from: Nicolás Bellora[Show abstract] [Hide abstract]
ABSTRACT: Matrin3 is an RNA- and DNA-binding nuclear matrix protein found to be associated with neural and muscular degenerative diseases. A number of possible functions of Matrin3 have been suggested, but no widespread role in RNA metabolism has yet been clearly demonstrated. We identified Matrin3 by its interaction with the second RRM domain of the splicing regulator PTB. Using a combination of RNAi knockdown, transcriptome profiling and iCLIP, we find that Matrin3 is a regulator of hundreds of alternative splicing events, principally acting as a splicing repressor with only a small proportion of targeted events being co-regulated by PTB. In contrast to other splicing regulators, Matrin3 binds to an extended region within repressed exons and flanking introns with no sharply defined peaks. The identification of this clear molecular function of Matrin3 should help to clarify the molecular pathology of ALS and other diseases caused by mutations of Matrin3. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.The EMBO Journal 01/2015; 34(5). DOI:10.15252/embj.201489852 · 10.75 Impact Factor
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ABSTRACT: In the present study, we studied changes in gene expression induced by chemotherapy (CT) on normal peripheral blood leukocytes (PBLs), at baseline and following three CT cycles, in order to identify which genes were specifically affected and were potentially useful as biomarkers for a personalised prognosis and follow-up. A PBL subtraction cDNA library was constructed from four patients undergoing CT with paclitaxel and carboplatin (PC). mRNA from the PBLs was isolated prior to the patients receiving the first cycle and following the completion of the third cycle. The library was screened and the expression of the identified genes was studied in PBLs obtained from patients suffering from cancer prior to and following three cycles of PC and a reference group of patients undergoing treatment with Adriamycin-cyclophosphamide (AC). From the 1,200 screened colonies, 65 positive clones showed varied expression intensity and were sequenced; 27 of these were mitochondrial DNA and 38 clones (27 different) were coded for cytosolic and nuclear proteins. The genes that were studied in patients undergoing CT were ATM (ataxia-telangiectasia mutated gene), eIF4B (translation initiation factor 4B), MATR3 (Matrin 3), MORC3 (microrchidia 3), PCMTD2 (protein-L-isoaspartate O-methyltransferase), PDCD10 (programmed cell death gene 10), PSMB1 (proteasome subunit type β), RMND5A (required for meiotic nuclear division 5 homologue A), RUNX2 (runt-related transcription factor 2), SACM1L (suppressor of actin mutations 1-like), TMEM66 (transmembrane protein 66) and ZNF644 (zinc finger protein 644). Certain variations were observed in the expression of the genes that are involved in drug resistance mechanisms, some of which may be secondary to non-desirable effects and others of which may cause the undesired effects of CT. The expression of genes with a dynamic cellular role showed a marked positive correlation, indicating that their upregulation may be involved in a specific pattern of cell survival versus apoptosis in response to the cell damage induced by CT. Whether these CT-induced changes are random or directed in a specific selection-evolution manner needs to be elucidated.Oncology letters 06/2012; 3(6):1341-1349. DOI:10.3892/ol.2012.669 · 0.99 Impact Factor
Article: Neuroproteomics: an insight into ALS[Show abstract] [Hide abstract]
ABSTRACT: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of unknown aetiology. Diagnosis is made through physical examination, electrophysiological findings, and by excluding other conditions. There is not a single biomarker that concludes the diagnosis. The aim of this study was to investigate differentially expressed proteins in cerebrospinal fluid (CSF) of ALS patients compared to control subjects, with the purpose to identify a panel of possible biomarkers for the disease. The differentially expressed spots/proteins were submitted to two-dimensional (2D) electrophoresis and recognized with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. Parkin-like and many iron and zinc binding were some of the proteins found in ALS CSF. Parkin is a ligase involved in ubiquitin-proteasome pathway and mutations in the parkin gene are the most common cause of recessive familial Parkinson's disease. Iron and zinc are involved with many important metabolic processes and are related to neurodegenerative disease. Common features of ALS comprise failure of the ubiquitin-proteasome system and increased levels of metal ions in the brain. Therefore, the identification of these proteins can be a significant step in ALS research. These and other identified proteins are discussed in this study.Neurological Research 12/2012; 34(10):937-43. DOI:10.1179/1743132812Y.0000000092 · 1.45 Impact Factor