Hiromasa Ono

Gateways to the FANTOM5 promoter level mammalian expression atlas

The FANTOM5 project investigates transcription initiation activities in more than 1,000 human and mouse primary cells, cell lines and tissues using CAGE. Based on manual curation of sample information and development of an ontology for sample classification, we assemble the resulting data into a centralized data resource (http://fantom.gsc.riken.jp/5/). This resource contains web-based tools and data-access points for the research community to search and extract data related to samples, genes, promoter activities, transcription factors and enhancers across the FANTOM5 atlas.

BioHackathon series in 2011 and 2012: penetration of ontology and linked data in life science domains

The application of semantic technologies to the integration of biological data and the interoperability of bioinformatics analysis and visualization tools has been the common theme of a series of annual BioHackathons hosted in Japan for the past five years. Here we provide a review of the activities and outcomes from the BioHackathons held in 2011 in Kyoto and 2012 in Toyama. In order to efficiently implement semantic technologies in the life sciences, participants formed various sub-groups and worked on the following topics: Resource Description Framework (RDF) models for specific domains, text mining of the literature, ontology development, essential metadata for biological databases, platforms to enable efficient Semantic Web technology development and interoperability, and the development of applications for Semantic Web data. In this review, we briefly introduce the themes covered by these sub-groups. The observations made, conclusions drawn, and software development projects that emerged from these activities are discussed.

Gene expression profiling in multipotent DFAT cells derived from mature adipocytes.

Cellular dedifferentiation signifies the withdrawal of cells from a specific differentiated state to a stem cell-like undifferentiated state. However, the mechanism of dedifferentiation remains obscure. Here we performed comparative transcriptome analyses during dedifferentiation in mature adipocytes (MAs) to identify the transcriptional signatures of multipotent dedifferentiated fat (DFAT) cells derived from MAs. Using microarray systems, we explored similarly expressed as well as significantly differentially expressed genes in MAs during dedifferentiation. This analysis revealed significant changes in gene expression during this process, including a significant reduction in expression of genes for lipid metabolism concomitantly with a significant increase in expression of genes for cell movement, cell migration, tissue developmental processes, cell growth, cell proliferation, cell morphogenesis, altered cell shape, and cell differentiation. Our observations indicate that the transcriptional signatures of DFAT cells derived from MAs are summarized in terms of a significant decrease in functional phenotype-related genes and a parallel increase in cell proliferation, altered cell morphology, and regulation of the differentiation of related genes. A better understanding of the mechanisms involved in dedifferentiation may enable scientists to control and possibly alter the plasticity of the differentiated state, which may lead to benefits not only in stem cell research but also in regenerative medicine.

Comparative gene expression analysis of zebrafish and mammals identifies common regulators in hematopoietic stem cells

Hematopoiesis in teleost fish is maintained in the kidney. We previously reported that Hoechst dye efflux activity of hematopoietic stem cells (HSCs) is highly conserved in vertebrates, and that Hoechst can be used to purify HSCs from teleost kidneys. Regulatory molecules that are strongly associated with HSC activity may also be conserved in vertebrates. In this study, we identified evolutionarily conserved molecular components in HSCs by comparing the gene expression profiles of zebrafish, murine, and human HSCs. Microarray data of zebrafish kidney side population cells (zSPs) showed that genes involved in cell junction and signal transduction tended to be up-regulated in zSPs, whereas genes involved in DNA replication tended to be down-regulated. These properties of zSPs were similar to those of mammalian HSCs. Overlapping gene expression analysis showed that 40 genes were commonly up-regulated in these 3 HSCs. Some of these genes, such as egr1, gata2, and id1, have been previously implicated in the regulation of HSCs. In situ hybridization in zebrafish kidney revealed that expression domains of egr1, gata2, and id1 overlapped with that of abcg2a, a marker for zSPs. These results suggest that the overlapping genes identified in this study are regulated in HSCs and play important roles in their functions.

Update of the FANTOM web resource: high resolution transcriptome of diverse cell types in mammals

Upon the first publication of the fifth iteration of the Functional Annotation of Mammalian Genomes collaborative project, FANTOM5, we gathered a series of primary data and database systems into the FANTOM web resource (http://fantom.gsc.riken.jp) to facilitate researchers to explore transcriptional regulation and cellular states. In the course of the collaboration, primary data and analysis results have been expanded, and functionalities of the database systems enhanced. We believe that our data and web systems are invaluable resources, and we think the scientific community will benefit for this recent update to deepen their understanding of mammalian cellular organization. We introduce the contents of FANTOM5 here, report recent updates in the web resource and provide future perspectives.

Identification of key uric acid synthesis pathway in a unique mutant silkworm Bombyx mori model of Parkinson's disease.

Plasma uric acid (UA) levels decrease following clinical progression and stage development of Parkinson’s disease (PD). However, the molecular mechanisms underlying decreases in plasma UA levels remain unclear, and the potential to apply mutagenesis to a PD model has not previously been discovered. We identified a unique mutant of the silkworm Bombyx mori (B.mori) op. Initially, we investigated the causality of the phenotypic “op” by microarray analysis using our constructed KAIKO functional annotation pipeline. Consequently, we found a novel UA synthesis-modulating pathway, from DJ-1 to xanthine oxidase, and established methods for large-scale analysis of gene expression in B. mori. We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented. Additionally, levels of B.mori tyrosine hydroxylase (TH) and DJ-1 mRNA were significantly lower in the brain of B. mori op mutants. UA content was significantly lower in the B. mori op mutant tissues and hemolymph. The possibility that the B. mori op mutant might be due to loss of DJ-1 function was supported by the observed vulnerability to oxidative stress. These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant. In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress. Our findings are expected to provide information needed to elucidate the molecular mechanism of decreased plasma UA levels in the clinical stage progression of PD.

Superoxide dismutases, SOD1 and SOD2, play a distinct role in the fat body during pupation in silkworm Bombyx mori.

One way that aerobic biological systems counteract the generation of reactive oxygen species (ROS) is with superoxide dismutase proteins SOD1 and SOD2 that metabolize superoxide radicals to molecular oxygen and hydrogen peroxide or scavenge oxygen radicals produced by the extensive oxidation-reduction and electron-transport reactions that occur in mitochondria. We characterized SOD1 and SOD2 of Bombyx mori isolated from the fat body of larvae. Immunological analysis demonstrated the presence of BmSOD1 and BmSOD2 in the silk gland, midgut, fat body, Malpighian tubules, testis and ovary from larvae to adults. We found that BmSOD2 had a unique expression pattern in the fat body through the fifth instar larval developmental stage. The anti-oxidative functions of BmSOD1 and BmSOD2 were assessed by exposing larvae to insecticide rotenone or vasodilator isosorbide dinitrate, which is an ROS generator in BmN4 cells; however, exposure to these compounds had no effect on the expression levels of either BmSOD protein. Next, we investigated the physiological role of BmSOD1 and BmSOD2 under environmental oxidative stress, applied through whole-body UV irradiation and assayed using quantitative RT-PCR, immunoblotting and microarray analysis. The mRNA expression level of both BmSOD1 and BmSOD2 was markedly increased but protein expression level was increased only slightly. To examine the differences in mRNA and protein level due to UV irradiation intensity, we performed microarray analysis. Gene set enrichment analysis revealed that genes in the insulin signaling pathway and PPAR signaling pathway were significantly up-regulated after 6 and 12 hours of UV irradiation. Taken together, the activities of BmSOD1 and BmSOD2 may be related to the response to UV irradiation stress in B. mori. These results suggest that BmSOD1 and BmSOD2 modulate environmental oxidative stress in the cell and have a specific role in fat body of B. mori during pupation.

Dedifferentiated follicular granulosa cells derived from pig ovary can transdifferentiate into osteoblasts.

Transdifferentiation is the conversion of cells from one differentiated cell type into another. How functionally differentiated cells already committed to a specific cell lineage can transdifferentiate into other cell types is a key question in cell biology and regenerative medicine. In the present study we show that porcine ovarian follicular GCs (granulosa cells) can transdifferentiate into osteoblasts in vitro and in vivo. Pure GCs isolated and cultured in Dulbeccos modified Eagles medium supplemented with 20% FBS (fetal bovine serum) proliferated and dedifferentiated into fibroblast-like cells. We referred to these cells as DFOG (dedifferentiated follicular granulosa) cells. Microarray analysis showed that DFOG cells lost expression of GC-specific marker genes, but gained the expression of osteogenic marker genes during dedifferentiation. After osteogenic induction, DFOG cells underwent terminal osteoblast differentiation and matrix mineralization in vitro. Furthermore, when DFOG cells were transplanted subcutaneously into SCID mice, these cells formed ectopic osteoid tissue. These results indicate that DFOG cells derived from GCs can differentiate into osteoblasts in vitro and in vivo. We suggest that GCs provide a useful model for studying the mechanisms of transdifferentiation into other cell lineages in functionally differentiated cells.

Tutorial videos of bioinformatics resources: online distribution trial in Japan named TogoTV

In recent years, biological web resources such as databases and tools have become more complex because of the enormous amounts of data generated in the field of life sciences. Traditional methods of distributing tutorials include publishing textbooks and posting web documents, but these static contents cannot adequately describe recent dynamic web services. Due to improvements in computer technology, it is now possible to create dynamic content such as video with minimal effort and low cost on most modern computers. The ease of creating and distributing video tutorials instead of static content improves accessibility for researchers, annotators and curators. This article focuses on online video repositories for educational and tutorial videos provided by resource developers and users. It also describes a project in Japan named TogoTV (http://togotv.dbcls.jp/en/) and discusses the production and distribution of high-quality tutorial videos, which would be useful to viewer, with examples. This article intends to stimulate and encourage researchers who develop and use databases and tools to distribute how-to videos as a tool to enhance product usability.

RefEx, a reference gene expression dataset as a web tool for the functional analysis of genes

Gene expression data are exponentially accumulating; thus, the functional annotation of such sequence data from metadata is urgently required. However, life scientists have difficulty utilizing the available data due to its sheer magnitude and complicated access. We have developed a web tool for browsing reference gene expression pattern of mammalian tissues and cell lines measured using different methods, which should facilitate the reuse of the precious data archived in several public databases. The web tool is called Reference Expression dataset (RefEx), and RefEx allows users to search by the gene name, various types of IDs, chromosomal regions in genetic maps, gene family based on InterPro, gene expression patterns, or biological categories based on Gene Ontology. RefEx also provides information about genes with tissue-specific expression, and the relative gene expression values are shown as choropleth maps on 3D human body images from BodyParts3D. Combined with the newly incorporated Functional Annotation of Mammals (FANTOM) dataset, RefEx provides insight regarding the functional interpretation of unfamiliar genes. RefEx is publicly available at http://refex.dbcls.jp/.