201810Jono

研究発表を行った学会；The XVIth International Symposium on Amyloidosis (ISA2018)
2018年 3月26日〜29日（Kumamoto）
タイトル； Effects of Cyclodextrin/Dendrimer Conjugate/shRNA Complex as a Novel Multi-target Drug on Amyloidoses.
発表者；城野　博史氏
（熊本大学　医学部附属病院　薬剤部・臨床薬物動態分野）
要旨；
INTRODUCTION: It is well-documented that amyloidoses progress through 3 critical pathological processes, such as, 1. Overproduction or mutation of amyloid precursor proteins, 2. Amyloid fibril formation caused by conformational change, 3. Tissue deposition of amyloid fibrils. To target and suppress each pathological process simultaneously with single treatment, we utilized characteristic features of polyamidoamine starburst dendrimer as a multifunctional material & gene transfer carrier, and developed glucuronylglucosyl-β-CyD/Dendrimer conjugate (GUG-β-CDE). In this study, we used GUG-β-CDE/ short hairpin RNA (shRNA) complex as a novel multi-target drug for effectively suppressing 3 pathological process in parallel, and evaluated its therapeutic effects on various types of amyloidosis.
MATERIALS & METHODS: Therapeutic effects of GUG-β-CDE only or GUG-β-CDE/shRNA complex on various amyloid precursor proteins, such as transthyretin (TTR) in TTR amyloidosis and amyloid β (Aβ) in Alzheimer’s disease, were evaluated in this study. Gene silencing effect was examined by using quantitative PCR (qPCR). Inhibitory effects on amyloid fibril formation and dissolving effects on amyloid fibrils were evaluated by Thioflavin-T (Th-T) assay in vitro. In addition, human TTR V30M Transgenic (Tg) rats were treated with GUG-β-CDE (2 mg/kg) or GUG-β-CDE (2 mg/kg)/shTTR (0.053 mg/kg) complex by tail vain injection, and evaluated their therapeutic effects by determining TTR deposition in colon by immunohistochemical staining and ELISA assay.
RESULTS: GUG-β-CDE/shRNA against TTR (siTTR) complex significantly reduced TTR expression at mRNA levels by assessing qPCR. GUG-β-CDE/shTTR complex also exhibited both inhibitory effects on TTR amyloid fibril formation and dissolving effects on TTR amyloid fibrils in vitro. Interestingly, those therapeutic effects were synergistically enhanced by GUG-β-CDE/shTTR complex, compared with GUG-β-CDE treatment only. Consistent with those in vitro results, GUG-β-CDE/shTTR complex exhibited the synergistic therapeutic effects in TTR V30M Tg rats in vivo, as assessed by significant reduction of TTR deposition in colon. Furthermore, those synergistic effects of GUG-β-CDE/shRNA complex was also observed in Aβ amyloid formation process.
DISCUSSION & CONCLUSIONS: Our results suggest that GUG-β-CDE/shRNA complex may have potential as a multi-target drug for amyloidoses by suppressing 3 pathological process of amyloidoses simultaneously with single treatment. By selecting suitable gene specific RNAi medicine, our multi-target drug may also be applicable for various types of amyloidosis.