Biomedical subjects

Naohiko Shimada

Publications and source records attributed to Naohiko Shimada.

3 recordsLinked to original sources

PubMed2004

Transcriptome analysis using fluorescence-labeled oligonucleotide.

In our previous studies, the fluorescence intensity at 480 nm of the bispyrene-labeled 2'-O-methyl-oligoribonucleotide (OMUpy2) was drastically enhanced only when it was hybridized with its complementary RNA. In this study, we demonstrated the potential of the OMUpy2 for transcriptome analysis in the cell free system and in the living cell. For the analysis in the cell free system, the micro-chamber was designed and used to evaluate the detection limit of the target RNA. The detection limit of oligo-RNA was approximately 15 fmol. For the analysis of the living cells, C-OMUpy2 was introduced to the cervical carcinoma cells, C4II, and the fluorescence from C-OMUpy2 was monitored. The fluorescence from the cells began to be observed 5 min after the serum stimulation, and the fluorescence was decreased after 20 min. These results seemed to be consistent with the results from the RT-PCR analysis and suggested that OMUpy2 could be a useful tool for the transcriptome analysis.

Cell Line, Tumor↗

PubMed2002

Selection of RNA-binding peptides containing Arg-rich motif.

In order to search the RNA-binding peptides, selection from randomized peptides containing Arg-rich motif was carried out using rRNA-immobilized column. As a result of the selection for 16S- and 23S-rRNA from E. coli, six peptides were identified to be the rRNA-binding peptide by MALDI-TOF MS. These peptides contained R, N, Q, or G at three randomized positions. This result indicates that amino acids with a positive residue or an amide residue might be essential for peptides to recognize the RNA.

Amino Acid Motifs↗

PubMedDate not supplied

Synthesis and in vitro characterization of antigen-conjugated polysaccharide as a CpG DNA carrier.

Oligodeoxynucleotides containing unmethylated CpG sequences (CpG DNAs) are known as an immune adjuvant. CpG DNAs coupled with a particular antigen enabling both CpG DNA and antigen delivery to the same antigen-presenting cell have been shown to be more effective. Based on our previous finding that beta-(1-->3)-D-glucan schizophyllan (SPG) can be used as a CpG DNA carrier, here we present the synthesis of an antigen-conjugated SPG and the characterization of the conjugate. Ovalbumin (OVA, 43 kDa) was used as a model antigen, and two OVA were conjugated to one SPG molecule (M(w) = 150,000), denoted by OVA-SPG. Circular dichroism and gel electrophoresis showed that OVA-SPG could form a complex with a (dA)(40)-tailed CpG DNA at the 3' end (1,668-(dA)(40)). When OVA-SPG was added to macrophages (J774.A1), the amount of the ingested OVA-SPG was increased compared with that of OVA itself, suggesting that Dectin-1 (proinflammatory nonopsonic receptor for beta-glucans) is involved to ingest OVA-SPG. Furthermore, the complex of the conjugate and DNA was co-localized in the same vesicles, implying that OVA (antigen) and CpG DNA (adjuvant) were ingested into the cell at the same time. This paper shows that OVA-SPG can be used as a CpG DNA carrier to induce antigen-specific immune responses.

Adjuvants, Immunologic↗