Ryotaro Irie

Redifferentiation of dedifferentiated chondrocytes and chondrogenesis of human bone marrow stromal cells via chondrosphere formation with expression profiling by large-scale cDNA analysis

Characterization of dedifferentiated chondrocytes (DECs) and mesenchymal stem cells capable of differentiating into chondrocytes is of biological and clinical interest. We isolated DECs and bone marrow stromal cells (BMSCs), H4-1 and H3-4, and demonstrated that the cells started to produce extracellular matrices, such as type II collagen and aggrecan, at an early stage of chondrosphere formation. Furthermore, cDNA sequencing of cDNA libraries constricted by the oligocapping method was performed to analyze difference in mRNA expression profiling between DECs and marrow stromal cells. Upon redifferentiation of DECs, cartilage-related extracellular matrix genes, such as those encoding leucine-rich small proteoglycans, cartilage oligomeric matrix protein, and chitinase 3-like 1 (cartilage glycoprotein-39), were highly expressed. Growth factors such as FGF7 and CTGF were detected at a high frequency in the growth stage of monolayer stromal cultures. By combining the expression profile and flow cytometry, we demonstrated that isolated stromal cells, defined by CD34(-), c-kit(-), and CD140alpha(- or low), have chondrogenic potential. The newly established human mesenchymal cells with expression profiling provide a powerful model for a study of chondrogenic differentiation and further understanding of cartilage regeneration in the means of redifferentiated DECs and BMSCs.

HUNT: launch of a full-length cDNA database from the Helix Research Institute

The Helix Research Institute (HRI) in Japan is releasing 4356 HUman Novel Transcripts and related information in the newly established HUNT database. The institute is a joint research project principally funded by the Japanese Ministry of International Trade and Industry, and the clones were sequenced in the governmental New Energy and Industrial Technology Development Organization (NEDO) Human cDNA Sequencing Project. The HUNT database contains an extensive amount of annotation from advanced analysis and represents an essential bioinformatics contribution towards understanding of the gene function. The HRI human cDNA clones were obtained from full-length enriched cDNA libraries constructed with the oligo-capping method and have resulted in novel full-length cDNA sequences. A large fraction has little similarity to any proteins of known function and to obtain clues about possible function we have developed original analysis procedures. Any putative function deduced here can be validated or refuted by complementary analysis results. The user can also extract information from specific categories like PROSITE patterns, PFAM domains, PSORT localization, transmembrane helices and clones with GENIUS structure assignments. The HUNT database can be accessed at http://www.hri.co.jp/HUNT.

Reaction mechanism of photocatalysis for the liquid-phase dehydrogenation of 2-propanol with rhodium porphyrin complex

Abstract Liquid-phase dehydrogenation of 2-propanol proceeds selectively under visible light irradiation with a rhodium porphyrin complex catalyst. Kinetic studies have revealed that a bimolecular process between hydridorhodium porphyrin complexes in the photoexcited (π-π ∗ ) and ground states is involved in the photocatalytic cycle.

cDNA macroarray analysis of gene expression in synoviocytes stimulated with TNFα

Gene expression of synoviocytes stimulated with tumor necrosis factor‐α (TNFα) was studied by macroarray analysis to elucidate the cellular response and identify new biological functions of known and unknown genes. 10 035 cDNA clones were used to make cDNA macroarrays of representative genes. Synoviocytes expressed large amounts of fibronectin and collagen mRNA. Statistical analysis of the macroarray data revealed 26 genes, including six new genes, which underwent significant alteration of gene expression in response to TNFα stimulation. These findings suggest that the synoviocyte response to TNFα stimulation forms the basis of development of various aspects of the pathophysiology of rheumatoid arthritis.

Quantum chemical interpretation of the dihydrogen formation process in photocatalytic 2-propanol dehydrogenation with rhodium porphyrin complex

Abstract The role of photoactivation in a bimolecular process involving hydridorhodium porphyrin complexes was studied quantum chemically, based on the proposed photocatalytic reaction mechanism for the liquid-phase dehydrogenation of 2-propanol. The radiationless electron transition from a photo-excited porphyrin π ∗ orbital to a σ ∗ orbital in the configuration of (P ∗ )Rh-H·H-Rh(P) has been cited to cause the formation of a dihydrogen molecule.