アクティブボード・２０１５年　５月
　　　　　・・・・・２０１５年　５月　８日更新・・・・・
研究発表を行った学会；
・第16回北東アジアシンポジウム　(The16th Northeastern Asian Symposiumon Autophagy:from Basic to Medicine)
　２０１４年１２月１８日〜２１日（Busan, Korea）
タイトル；Autophagy and Pancreatitis.
発表者；大村谷　昌樹　氏
　　　（熊本大学　生命科学研究・支援センター　技術開発分野）
Abstract；
Background & Aims: Mutations in serine protease inhibitor Kazal type 1 (SPINK1) are associated with human chronic pancreatitis (CP). Genetic deletion of Spink3, mouse homolog of SPINK1, causes postnatal lethality precluding mechanistic investigations into the effects of SPINK deficiency. Here we have developed Spink3SPINK1/- transgenic mice (termed “SPINK1-in”) in which one ablated Spink3 allele is replaced by knocked-in SPINK1. This partial restoration of SPINK function rescues mice from lethality; but SPINK1-in mice progressively develop spontaneous CP.
Methods: We used Cre-Lox technology to generate Spink3SPINK1/- mice and their controls, Spink3SPINK1/+. Pancreas damage and pancreatitis responses were analyzed using light, fluorescence, and electron microscopy, immunoblotting, real-time PCR, and enzymatic assays.
Results: In contrast to Spink3SPINK1/+ and Spink3SPINK1/SPINK1, SPINK1-in mice within 4 weeks developed pancreas damage the earliest manifestations of which were impaired autophagy and increased trypsin activity. This resulted in accumulation of large vacuoles (with features of autolysosomes and crinophagy), macrophage-type inflammation, intralobular fibrosis with activated stellate cells, and acinar cell death, i.e., apoptosis. We also found lysosomal dysfunction manifest by increased cathepsin B activity and decreased level of LAMP2. Pancreas damage (i.e., vacuolization) was not prevented by Atg5 deletion.
Conclusions: SPINK1-in mice represent a novel, clinically relevant, genetic model of human CP, revealing the mechanisms whereby SPINK insufficiency causes CP. The results identify new targets of SPINK regulating autophagic and lysosomal pathways in pancreas.