Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcription profiling of rat retina during maturation

ABSTRACT: Recently we reported that the rat inner retina undergoes significant functional changes during maturation. Aiming to gain knowledge on additional aspects of retinal development and maturation, we used the microarray system to monitor gene expression patterns in the rat retina at ages 5, 11, and 20 weeks. The analysis revealed the expression of many well-documented retinal genes as well as a high number of nonâ??annotated genes. Quantitative realtime PCR analysis verified the microarray results in the majority of studied genes. A statistical analysis of the 4 microarray slides revealed 603 differentially expressed genes which were grouped into 6 expression clusters. A bioinformatic analysis of these clusters revealed sets of genes encoding proteins with functions that are likely to be relevant to inner retinal function (e.g. potassium, sodium, calcium, and chloride channels, synaptic vesicle transport, and axonogenesis). In addition, we performed a histological analysis of the maturing retina and studied different aspects of retinal structure. The analysis revealed a significant reduction of outer nuclear layer thickness between 11 and 19 weeks of age and a significant reduction of retinal ganglion cell number at 11 and 19 weeks comparing to 5 weeks. We identified in this study genes with differential expression pattern during retinal maturation. Some of the genes encode proteins that may be involved in the functional maturation of inner retinal cells. These data, taken together with our histological and electrophysiological data, contribute to our understanding of the developmental processes occurring in the retina of this widely-used animal model. Experiment Overall Design: Rat retinal samples at ages 5, 11, and 20 weeks were studied using 4 microarray slides in a dye-swap design: 5-11, 11-5, 5-20, and 20-5.

ORGANISM(S): Rattus norvegicus

SUBMITTER: Dror Sharon

PROVIDER: E-GEOD-8423 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:One Âµg of total RNA from either an; individual rat or from a pooled sample was amplified and labeled with a; fluorescent dye (either Cy3 or Cy5) using the Low RNA Input Linear Amplification Labeling kit (Agilent Technologies, Palo Alto, CA) following the manufacturerâ??s protocol. The amount and quality of the resulting fluorescently labeled cRNA was assessed using a Nanodrop ND-100 spectrophometer and an Agilent; Bioanalyzer. Equal amounts of Cy3- or Cy5-labeled cRNA were hybridized to the Agilent Rat Oligo Microarray (Agilent Technologies, Inc., Palo Alto, CA) for 17 hrs, prior to washing and scanning. Data was extracted from the resulting; images using Agilentâ??s Feature Extraction Software (Agilent Technologies, Inc., Palo Alto, CA). For day/night comparisons, two types of complementing hybridizations were performed: hepatic RNA from individual day rats was hybridized against a pool made up of RNA from 12 hour offset night rats, and RNA from individual night rats was hybridized against a pool made up of RNA from 12-hour offset day rats. Specifically, hepatic RNA samples from three individual day rats collected ten hours after light on (CT10) were hybridized against a pooled RNA sample composed of equal aliquots of RNA from the livers of six night rats collected ten hrs after lights off (CT22); and RNA samples from three individual night rats collected at CT22 were hybridized against a pooled RNA sample composed of equal aliquots of RNA from the livers of six day rats collected at CT10. This was replicated in a second study for a total of 24 hybridizations of 12 hour offset samples. For time of day comparisons, equal aliquots of RNA from the livers of six; rats collected at each of four different times of the circadian day (CT4, CT10, C16 and CT22) were pooled. The two replicate studies thus resulted in 8 pools (two replicate pools/time point times four time points); each pool was hybridized against a Universal Rat Reference RNA Standard (Stratagene, La Jolla, CA).

Project description:B-cell chronic lymphocytic leukemia (B-CLL) shows an incredibly high heterogeneity in the clinical course, spanning from rapidly aggressive to completely indolent behaviour. In order to identify the correspondent gene expression variability, we investigated 29 cases of untreated B-CLL using microarray. Firstly, two robust CLL clusters were identified applying multiple unsupervised clustering algorithms. Their separation was mainly determined by the differential expression of several genes included into two gene groups designated OxPhos and Lyn clusters. OxPhos gene cluster, previously identified in a subset of diffuse large B-cell lymphomas, comprises genes coding for some respiratory chain enzymes, ribosomal proteins and translation factors. Moreover, increased levels of genes involved in the regulation of apoptosis and in the proteasome-ubiquitin complex and the down-regulation of LYN gene, member of B-cell receptor pathway, characterized the OxPhos CLL subset. These B-CLL biological clusters did not reveal any preferential distribution of Ig mutated or Ig unmutated CLL prognostic groups. Furthermore, we applied another unsupervised algorithm (Subtractive Unsupervised Analysis) after the exclusion of genes characterizing the previously identified CLL subsets. At this point, we could identify two new CLL clusters, showing a clear association to the Ig mutational status. In addition to the ZAP-70 and LPL genes, the patients with unmutated Ig expressed higher level of some interesting genes involved in B cell activation, cell cycle regulation, apoptosis resistance and angiogenesis. In conclusion, we showed that B-CLL is characterized by an intrinsic heterogeneity in gene expression pattern, which overcomes the influence of the immunoglobulin mutational status on B-cell chronic lymphocytic leukemia profiles. SUBMITTER_CITATION: abstract in Blood, Volume 108, Issue 11 [2780] Angiopoietin-2 Expression in B-Cell Chronic Lymphocytic Leukemia: Association with Clinical Outcome and Immunoglobulin Heavy-Chain Mutational Status. "Rossana Maffei, Silvia Martinelli, Ilaria Castelli, Rita Santachiara, Elena Morandi, Patrizia Zucchini, Marcella Fontana, Anna Maria Colacci, Roberto Serra, Roberto Marasca, Giuseppe Torelli - Oncology and Hematology, University of Modena and Reggio Emilia, Modena, Italy; Excellence Environmental Carcinogenesis, ARPA, Bologna, Italy; Social, Cognitive and Quantitative Sciences, University of Modena and Reggio Emilia, Reggio Emilia, Ita Experiment Overall Design: Twenty-nine B-CLL patients, who have attended the haematology clinic of Modena Hospital, were enrolled in this study. Total RNA from mononuclear cells was isolated using RNeasy Mini Kit (QIAGEN, Valencia, CA, USA) according to the manufacturerâ??s instructions For all 29 specimens, fluorescently-labelled cRNA was generated by in vitro transcription using Low RNA Input Fluorescent Linear Amplification Kit (Agilent Technologies, Palo alto, CA, USA) according to the manufacturerâ??s instructions. Amplified cRNA of each patient was labelled with cyanine 5-CTP (Perkin-Elmer, NEN Life Science, Boston, MA, USA) in each experiment. Mix of equal amount of total RNAs from our cohort was used as reference control in all microarray gene-profiling experiments. Amplified reference cRNA was labelled with cyanine 3-CTP (Perkin-Elmer, NEN Life Science, Boston, MA, USA) in each experiment. Moreover, cRNA products were purified using RNeasy columns (Qiagen). 1 ï?g of Cy5-labelled cRNA was mixed with the same amount of Cy3-labelled reference cRNA and then mixed cRNAs were fragmented to an average size of ï?¾50-100 nt by incubation at 60Â°C for 30 min using in situ Hybridization kit-plus (Agilent). Samples were hybridized on Agilent Human 1A Oligo Microarray, ink-jet printed microarray, comprising 20,173 (60-mer) experimentally validated oligonucleotide probes (features).33 After hybridization for 17 h at 60Â°C, slides were washed according to Agilent SSC protocol instructions and then scanned using a confocal laser scanner (Agilent Technologies). Experiment Overall Design: Fluorescence data were analysed with Feature Extraction Software v.7.5 (Agilent Technologies). Log10 ratio of the dye-normalized Cy3 and Cy5 channel signals were calculated, then a p-value and a final error were obtained to establish the significance of each feature.

Project description:In the central nervous system (CNS) the transcription factor NF-kappaB is a key regulator of inflammation and secondary injury processes. Following trauma or disease, the expression of NF-kappaB-dependent genes is activated, leading to both protective and detrimental effects on CNS recovery. Here we show that transgenic inactivation of astroglial NF-kappaB in mice (GFAP-IkappaBalpha-dn mice) resulted in dramatic reduction of disease severity and improvement in functional recovery following EAE. This coincided with a higher presence of leukocytes in the cord and brain of transgenic mice at the chronic phase of the disease, when the functional recovery over WT mice was the most significant. We observed that expression of proinflammatory genes in both spinal cord and cerebellum was delayed and reduced, while the loss of neuronal-specific molecules essential for synaptic transmission was limited compared to WT mice. Furthermore, death of retinal ganglion cells in affected retinas was almost abolished, suggesting the activation of neuroprotective mechanisms. Our data indicate that inhibiting NF-kappaB in astrocytes results in neuroprotective effects following EAE, directly implicating astrocytes in the pathophysiology of this disease. Experiment Overall Design: All mice used were 2-4 months old obtained by breeding heterozygous GFAP-IkappaBalpha-dn males with WT females. WT littermates were used as controls. Spinal cords from WT and GFAP-IkappaBalpha-dn transgenic mice (1), naive or induced with experimental autoimmune encephalomyelitis (EAE) at 10, 17 and 80 days post-induction (dpi) were used to isolate RNA. 3 animals were used for each time point. Experiment Overall Design: To identify significantly expressed genes across all replicate arrays we used R software package LIMMA. Each individual array was normalized within the array using global loess normalization. “Between array” normalization was carried out using the “quantile” algorithm also found in the LIMMA package. Differential expression and False Discovery Rate were assessed by using linear model and empirical Bayes moderated F statistics.

Dataset Information

Transcription profiling of rat retina during maturation

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets