Validation of housekeeping genes for quantitative real-time PCR in in-vivo and in-vitro models of cerebral ischaemia

<p>Abstract</p> <p>Background</p> <p>Studies of gene expression in experimental cerebral ischaemia models can contribute to understanding the pathophysiology of brain ischaemia and to identifying prognostic markers and potential therapeutic targets. The normalization of relative qRT-PCR data using a suitable reference gene is a crucial prerequisite for obtaining reliable conclusions. No validated housekeeping genes have been reported for the relative quantification of the mRNA expression profile activated in in-vitro ischaemic conditions, whereas for the in-vivo model different reference genes have been used.</p> <p>The present study aims to determine the expression stability of ten housekeeping genes (Gapdh, β2m, Hprt, Ppia, Rpl13a, Oaz1, 18S rRNA, Gusb, Ywhaz and Sdha) to establish their suitability as control genes for in-vitro and in-vivo cerebral ischaemia models.</p> <p>Results</p> <p>The expression stability of the candidate reference genes was evaluated using the 2^-ΔC'Tmethod and ANOVA followed by Dunnett's test. For the in-vitro model using primary cultures of rat astrocytes, all genes analysed except for Rpl13a and Sdha were found to have significantly different levels of mRNA expression. These different levels were also found in the case of the in-vivo model of pMCAO in rats except for Hprt, Sdha and Ywhaz mRNA, where the expression did not vary. Sdha and Ywhaz were identified by geNorm and NormFinder as the two most stable genes.</p> <p>Conclusion</p> <p>We have validated endogenous control genes for qRT-PCR analysis of gene expression in in-vitro and in-vivo cerebral ischaemia models. For normalization purposes, Rpl13a and Sdha are found to be the most suitable genes for the in-vitro model and Sdha and Ywhaz for the in-vivo model. Genes previously used as housekeeping genes for the in-vivo model in the literature were not validated as good control genes in the present study, showing the need for careful evaluation for each new experimental setup.</p

Cav-1 Protein Levels in Serum and Infarcted Brain Correlate with Hemorrhagic Volume in a Mouse Model of Thromboembolic Stroke, Independently of rt-PA Administration.

Thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) is currently the only FDA-approved drug for acute ischemic stroke. However, its administration is still limited due to the associated increased risk of hemorrhagic transformation (HT). rt-PA may exacerbate blood-brain barrier (BBB) injury by several mechanisms that have not been fully elucidated. Caveolin-1 (Cav-1), a major structural protein of caveolae, has been linked to the endothelial barrier function. The effects of rt-PA on Cav-1 expression remain largely unknown. Here, Cav-1 protein expression after ischemic conditions, with or without rt-PA administration, was analyzed in a murine thromboembolic middle cerebral artery occlusion (MCAO) and in brain microvascular endothelial bEnd.3 cells subjected to oxygen/glucose deprivation (OGD). Our results show that Cav-1 is overexpressed in endothelial cells of infarcted area and in bEnd.3 cell line after ischemia but there is disagreement regarding rt-PA effects on Cav-1 expression between both experimental models. Delayed rt-PA administration significantly reduced Cav-1 total levels from 24 to 72 h after reoxygenation and increased pCav-1/Cav-1 at 72 h in the bEnd.3 cells while it did not modify Cav-1 immunoreactivity in the infarcted area at 24 h post-MCAO. Importantly, tissue Cav-1 positively correlated with Cav-1 serum levels at 24 h post-MCAO and negatively correlated with the volume of hemorrhage after infarction, the latter supporting a protective role of Cav-1 in cerebral ischemia. In addition, the negative association between baseline serum Cav-1 levels and hemorrhagic volume points to a potential usefulness of baseline serum Cav-1 levels to predict hemorrhagic volume, independently of rt-PA administration.This work was supported by grants from Instituto de Salud Carlos III and co-fnanced by the European Development Regional Fund “A Way to Achieve Europe” Health Strategic Action Program PI13/02258 and PI17/02123 (MC), PI20/00535 (IL), and Spanish Stroke Research Network RETICS RD12/0014/0010 (MC), and RD16/0019/0003 (JS), RD16/0019/0004 (MC), and RD16/0019/0009 (IL); from Regional Madrid Government B2017/BMD- 3688 (IL); from Spanish Ministry of Science and Innovation PID2019-106581RBI00 (MAM); from Leducq Foundation for Cardiovascular Research TNE-19CVD01 (MAM); and from Fundación La Caixa HR17_00527 (MAM). P. Comajoan was a recipient of a predoctoral fellowship from the University of Girona (IF-UdG 2015).S

Nuevos determinantes moleculares en la respuesta a isquemia cerebral

Cerebral ischaemia is a potent inducer of gene expression, however, little is known about the mechanisms that regulate this expression. Studies of gene expression and the study of the mechanisms regulating this expression allow identifying new molecules regulated by ischaemia and possibly involved in the physiopathology of stroke. This thesis shows, (1) the importance of validating suitable endogenous controls for the studies of gene expression for each experimental condition; (2)that Gcf2/Lrrfip1 presents as a gene with diverse isoforms that are differentially expressed in response to stroke and that rLrrfip1, which has a possible protector role, is the main isoform; and (3) that the differential expression of the microRNAs remains from the acute to the chronic phase of ischaemia, having determined that miR-347 promotes neuronal apoptosis and Acsl4 and Arf3, potential targets of microRNAs differentially expressed in response to ischaemia, are new proteins to study in the physiopathology of stroke.La isquèmia cerebral és un potent inductor de l’expressió gènica, en canvi, poc es coneix sobre els mecanismes que regulen aquesta expressió. Els estudis d’expressió gènica i l’estudi dels mecanismes reguladors d’aquesta expressió permeten identificar noves molècules regulades per la isquèmia i possiblement implicades en la fisiopatologia de l’ictus. Aquesta tesi mostra, (1) la importància de validar els controls endògens idonis per als estudis d’expressió gènica per cada condició experimental; (2) que Gcf2/Lrrfip1 és un gen amb diverses isoformes diferencialment expressades en resposta a la isquèmia, sent rLrrfip1 la isoforma principal amb un possible rol protector; i (3) que l’expressió diferencial dels microRNAs es manté des de la fase aguda fins la fase crònica de la isquèmia, havent determinat que el miR-347 promou l’apoptosis neuronal i que Acsl4 i Arf3, potencials dianes de microRNAs diferencialment expressats en resposta a la isquèmia, són noves proteïnes d’estudi en la fisiopatologia de l’ictus

Clinical Parameters and Epigenetic Biomarkers of Plaque Vulnerability in Patients with Carotid Stenosis

Atheromatous disease is the first cause of death and dependency in developed countries and carotid artery atherosclerosis is one of the main causes of severe ischaemic strokes. Current management strategies are mainly based on the degree of stenosis and patient selection has limited accuracy. This information could be complemented by the identification of biomarkers of plaque vulnerability, which would permit patients at greater and lesser risk of stroke to be distinguished, thus enabling a better selection of patients for surgical or intensive medical treatment. Although several circulating protein-based biomarkers with significance for both the diagnosis of carotid artery disease and its prognosis have been identified, at present, none have been clinically implemented. This review focuses especially on the most relevant clinical parameters to take into account in routine clinical practice and summarises the most up-to-date data on epigenetic biomarkers of carotid atherosclerosis and plaque vulnerability

Liquid Chromatography Fingerprint Analysis of Released Compounds in Plasma Samples of Stroke Patients after Thrombolytic Treatment

Plasma samples obtained from stroke patients treated with recombinant tissue-type plasminogen activator (rt-PA) and not treated with rt-PA were evaluated with different HPLC methodologies to obtain information about the possible release of small molecules as a result of the thrombolytic treatment. Plasma samples, without derivatization and derivatized with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC), were evaluated with a HPLC gradient method, which consisted of a mobile phase of 10 mM ammonium acetate buffered solution (pH = 5.3) and acetonitrile. Three different detection methods were applied: UV, fluorescence, and ESI-MS. The results obtained showed that a group of new highly hydrophilic compounds appeared in most samples analyzed from treated patients, just after the administration of rt-PA. These compounds appeared shortly after the administration of the drug and were detected during the first 24 h after treatment, disappearing from plasma after this time. These new compounds were not detected either in controls or in non-treated stroke patients, which suggests that they were released into the plasma as a consequence of the thrombolytic effect of the drug. Our results suggest that these new compounds might be free glycans. The use of AQC as a derivatizing reagent has demonstrated that the new compounds detected cannot contain primary or secondary amine groups in their structure. The molecular mass determined by ESI-MS (821 Da) suggests that if these compounds are free glycans they might be a high-mannose type

La enseñanza de la lengua

Volumen que recoge ponencias y comunicaciones presentadas en el XIV Seminario Internacional sobre Educación y lenguas, celebrado en Sitges en 1989. En ellas se expone lo referente a la enseñanza de la lengua materna y de lenguas extranjeras en la escuela, su propuesta curricular y las líneas de actuación.CataluñaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5; 28014 Madrid; Tel. +34917748000; [email protected]

Llengua catalana i literatura : investigació, innovació i bones práctiques

Bibliografía al final de los capítulos. Resumen basado en el de la publicaciónSe pretende ofrecer ayuda al profesorado para la práctica en el aula. Se aportan algunos recursos que ayudan a llevar a cabo la actividad docente y sirven de base a la reflexión sobre las formas de enseñar y aprender lengua y literatura catalana en la enseñanza secundaria. Se destacan algunos capítulos. En los dos primeros capítulos se ofrecen instrumentos para la reflexión sobre la práctica en la enseñanza. Más adelante se tratan tres aspectos relevantes: la enseñanza de la gramática, del resumen y la lengua oral a partir de la investigación que los alumnos llevan a cabo. El cuarto capítulo es un ejemplo de integración de objetivos en una actividad de una gran riqueza de contenidos que hacen referencia a conocimientos y actitudes sociolingüísticas.CataluñaBiblioteca del Ministerio de Educación y Formación Profesional; Calle San Agustín, 5; 28014 Madrid; Tel. +34917748000; [email protected]

Cold stress protein RBM3 responds to hypothermia and is associated with good stroke outcome

RNA-binding motif protein 3 is a molecular marker of hypothermia that has proved neuroprotective in neurodegenerative disease models. However, its relationship to the well-recognized therapeutic effect of hypothermia in ischaemic stroke had not been studied. In this work, the expression of RNA-binding motif protein 3 was investigated in ischaemic animal models subjected to systemic and focal brain hypothermia, specifically the effects of RNA-binding motif protein 3 silencing and overexpression on ischaemic lesions. Moreover, the association of RNA-binding motif protein 3 levels with body temperature and clinical outcome was evaluated in two independent cohorts of acute ischaemic stroke patients (n = 215); these levels were also determined in a third cohort of 31 patients derived from the phase III EuroHYP-1 trial of therapeutic cooling in ischaemic stroke. The preclinical data confirmed the increase of brain RNA-binding motif protein 3 levels in ischaemic animals subjected to systemic and focal hypothermia; this increase was selectively higher in the cooled hemisphere of animals undergoing focal brain hypothermia, thus confirming the direct effect of hypothermia on RNA-binding motif protein 3 expression, while RNA-binding motif protein 3 up-regulation in ischaemic brain regions led to functional recovery. Clinically, patients with body temperature <37.5°C in the first two cohorts had higher RNA-binding motif protein 3 values at 24 h and good outcome at 3 months post-ischaemic stroke, while RNA-binding motif protein 3 levels in the cooled third cohort tended to exceed those in placebo-treated patients. These results make RNA-binding motif protein 3 a molecular marker associated with the effect of hypothermia in ischaemic stroke and suggest its potential application as a promising protective target. Hypothermia is an effective neuroprotective treatment in stroke. We have demonstrated that the expression of RBM3 is increased under hypothermia treatment in animal models of ischaemia and stroke patients. These results evidence the potential application of RBM3 as a promising protective target against ischaemi