細菌感染に伴う組織脂肪酸組成の変動

京都大学0048新制・論文博士医学博士論医博第260号新制||医||96(附属図書館)1090(主査)教授 永井 秀夫, 教授 田部井 和, 教授 早石 修学位規則第5条第2項該当Kyoto UniversityDA

Novel form of miR-29b suppresses bleomycin-induced pulmonary fibrosis.

MicroRNA 29b (miR-29b) replacement therapy is effective for suppressing fibrosis in a mouse model. However, to develop clinical applications for miRNA mimics, the side effects of nucleic acid drugs have to be addressed. In this study, we focused on miRNA mimics in order to develop therapies for idiopathic pulmonary fibrosis. We developed a single-stranded RNA, termed "miR-29b Psh-match," that has a unique structure to avoid problems associated with the therapeutic uses of miRNAs. A comparison of miR-29b Psh-match and double-stranded one, termed "miR-29b mimic" indicated that the single-stranded form was significantly effective towards fibrosis according to both in vivo and in vitro experiments. This novel form of miR-29b may become the foundation for developing an effective therapeutic drug for pulmonary fibrosis

miR-29b protects fibrotic responses in NIH/3T3 cells induced with TGF-β without activating TLRs.

<p>(A) <i>Col1a1</i> mRNA expression in NIH/3T3 cells was reduced after transfection with miR-29b Psh-match compared with cells treated only with TGF-β. The degree of reduction in <i>COL1A1</i> expression induced by miR-29b Psh-match transfection was greater than that induced by either miR-29b scrambled control or miR-29b mimic (Fig 2A) (*P<0.05). (B) miR-29b Psh-match does not induce TLR signaling activity. TLR signaling activity was measured using an NF-κB reporter in which luciferase cDNA was placed under the control of the κB response element. The dsRNA and ssRNA induce the activation of NF-κB through TLR3 and TLR7, respectively.</p

Bleomycin-induced pulmonary fibrosis in mouse lungs.

<p>(A) Images of lungs from mice that were either subject to nasal administration of methylene blue (right) or not (left). (B) Fold changes in <i>Col1a1</i> mRNA showed a peak one week after bleomycin administration. (*P<0.05) (C) Histological staining by HE and Masson’s trichrome showed pronounced diffuse fibrosis in the lungs three weeks after bleomycin administration.</p

miR-29b Psh-match suppresses pulmonary fibrosis in mice to a greater degree than miR-29b mimic.

<p>(A) In bleomycin-induced pulmonary fibroblast model mice, quantitative real-time PCR data indicates an increase in <i>Col1a1</i> mRNA expression. Expression of <i>Col1a1</i> decreased in the lungs of mice administered with miR-29b Psh-match relative to mice administered with either PBS, miR-29b scrambled control, or miR-29b mimic (*P<0.05). (B) HE and Masson’s trichrome staining showed the pronounced diffuse fibrosis on the lungs in the bleomycin-treated mice. Administration of miR-29b Psh-match suppressed pulmonary fibrosis in an established mouse model of bleomycin-induced pulmonary fibrosis (*P<0.05). High magnification images of the lungs of mice administered with either miR-29b mimic or Psh-match mice are shown in the frames. (C) Hydroxyproline content was measured as micrograms of hydroxyproline per weight in grams of the left lung’s tissues in mice.</p

Acerola exosome-like nanovesicles to systemically deliver nucleic acid medicine via oral administration

Extracellular vesicles derived from mammalian cells could be useful carriers for drug delivery systems (DDSs); however, with regard to clinical application, there are several issues to be overcome. Acerola (Malpighia emarginata DC.) is a popular health food. In this study, the feasibility of orally administered nucleic acid drug delivery by acerola exosome-like nanoparticles (AELNs) was examined. AELNs were recovered from acerola juice using an affinity column instead of ultracentrifugation. MicroRNA (miRNA) was sufficiently encapsulated in AELNs by 30-min incubation on ice and was protected against RNase, strong acid, and base treatments. The administration of an AELN/miRNA mixture in cells achieved downregulation of the miRNA’s target gene, and this mixture showed cytoplasmic localization. AELNs orally delivered small RNA to the digestive system in vivo. The target gene-suppressing effect in the small intestine and liver peaked 1 day after administration, indicating potential for use as an oral DDS for nucleic acid in the digestive system

Novel Types of Small RNA Exhibit Sequence- and Target-dependent Angiogenesis Suppression Without Activation of Toll-like Receptor 3 in an Age-related Macular Degeneration (AMD) Mouse Model

RNA interference (RNAi) has become a powerful tool for suppressing gene expression in vitro and in vivo. A great deal of evidence has demonstrated the potential for the use of synthetic small interfering RNAs (siRNAs) as therapeutic agents. However, the application of siRNA to clinical medicine is still limited, mainly due to sequence-independent suppression of angiogenesis mediated by Toll-like receptor 3 (TLR3). Here, we describe novel types of synthetic RNA, named nkRNA and PnkRNA, that exhibit sequence-specific gene silencing through RNAi without activating TLRs or RIG-I–like receptor signaling. In addition, we confirmed the therapeutic effect for the novel types of RNA in an animal model of age-related macular degeneration (AMD) without retinal degeneration. These data indicate that nkRNA and PnkRNA are of great potential utility as therapies against blinding choroidal neovascularization due to AMD