Articolele autorului Dumitru Iacobas
Link la profilul stiintific al lui Dumitru Iacobas

Organizational principles of the connexin-related brain transcriptome

We have found that deletion of genes encoding the gap junction proteins Cx43, Cx32 and Cx36 alter the expression levels of large numbers of genes in mouse brain located on all chromosomes and encoding proteins from all major functional categories. Gene regulation in Cx32 and Cx43 null brains was more similar than that in the Cx36 null brain, suggesting the possibility of transcriptomic controls exerted by both genes on both astrocytes and oligodendrocytes.

Read more
Gap junction and purinergic P2 receptor proteins as a functional unit: insights from transcriptomics

Gap junctions and purinergic P2 receptors (P2Rs) can be regarded as belonging to a common functional unit, given that they are involved in the transmission of calcium signals between cells. We have previously shown that deletion of the Gja1 gene alters expression levels of numerous genes encoding proteins with diverse functions, including purinergic receptors (P2Rs), and have found that genes synergistically or antagonistically expressed in wild-type

Read more
Connexin-dependent transcellular transcriptomic networks in mouse brain

Microarray experiments have generally focused on magnitude of gene expression changes in pathological conditions, thereby using the method as a high throughput screen to identify candidate marker genes and/or to validate phenotypic differences. We have used novel strategies to extract additional information from array studies, including expression variability and coordination, from which organizational principles of transcriptomes are emerging. We

Read more
The role of connexins on growth and gene expression

The purpose of this paper is to provide a brief overview of current thinking on the role of connexins, in particular Cx43, in growth regulation, and a more detailed discussion as to potential mechanisms involved with an emphasis on gene expression. While the precise molecular mechanism by which connexins can affect the growth of normal or tumor cells remains elusive, a number of exciting reports have expanded our understanding and are presented in

Read more
Connexin43 and the brain transcriptome of the newborn mice.

Our previously reported cDNA array datasets from neonatal wild-type and Cx43−/− (approved gene symbol Gja1) mouse brains were further analyzed to identify underlying interlinkages in the brain transcriptome. The analysis revealed that no gene cohort sharing either primary function or chromosomal location was significantly altered (up-and down-regulation were roughly balanced) in Cx43−/− brains, but each cohort exhibited significant perturbation

Read more
Transcriptomic changes in developing kidney exposed to chronic hypoxia.

cDNA arrays compared gene expression in kidneys of neonatal mice subjected to 1, 2, and 4 weeks of chronic constant (CCH) or intermittent (CIH) hypoxia with normoxic littermates. Five to twenty percent of genes were regulated in each condition, with greater changes in CCH. Up-regulation of 42% of the solute carriers after 1 week of CCH suggests a strong activation of pH controlling pathways. Significant reduction in expression change of genes important

Read more
Control and variability of gene expression in profile in evaluating the ecotoxin effects

the spotting microarray technique, consisting in large sets of DNA sequences spotted on poly-L-lysine coated glass microscope slides, was developed to analyze genome-wide expression patterns. It is a tool to quantitatively monitor gene expression profiles and to analyze the alterations produced by genetic diseases, or induced by treatments, abnormal nutrition and toxins. The pre-hilbert space of standard gene expression, based on the normal variability

Read more
Co-ordinated transcriptomics and the Theory of Genomic Patholog as new tools in drug discovery
Improved procedures to mine data obtained from spotted cDNA arrays

We studied six types of errors that affect the experimental results obtained with the spotted cDNA technology, proposing a new experimental strategy and a four-step algorithm to improve data accuracy. In an experiment analyzed with this method, mRNA extracted from neuroblastoma (N2A) cells and a clone transfected with the neuronal gap junction protein Cx36 were hybridized on 10 chips, each spotted with 2512 known mouse cDNAs. We found 53 upregulated

Read more
Hits and misses from gene expression ratio measurements in cDNA microarray studies

cDNA microarray users face many challenges to obtain accurate results, including complex technical errors, natural variability of biological systems, imperfect reproducibility of reference standards, and difficulties in acquisition and processing of large amounts of data. Therefore, investigators should be aware of potential sources of variability and account for them in the experimental design and execution. This work reports our experience in identifying

Read more