Kim Eun-Kyung, Kwon Kang-Beom, Han Mi-Jeong, Song Mi-Young, Lee Ji-Hyun, Lv Na, Ka Sun-O, Yeom Seung-Ryong, Kwon Young-Dal, Ryu Do-Gon, Kim Kang-San, Park Jin-Woo, Park Raekil, Park Byung-Hyun
Department of Biochemistry, Medical School and Institute for Medical Sciences, Chonbuk National University, Jeonju 561-756, Korea.
Exp Mol Med. 2007 Apr 30;39(2):149-59. doi: 10.1038/emm.2007.17.
We demonstrated previously that Coptidis rhizoma extract (CRE) prevented S-nitroso-N-acetylpenicillamine-induced apoptotic cell death via the inhibition of mitochondrial membrane potential disruption and cytochrome c release in RINm5F (RIN) rat insulinoma cells. In this study, the preventive effects of CRE against cytokine-induced beta-cell death was assessed. Cytokines generated by immune cells infiltrating pancreatic islets are crucial mediators of beta-cell destruction in insulin-dependent diabetes mellitus. The treatment of RIN cells with IL-1beta and IFN-gamma resulted in a reduction of cell viability. CRE completely protected IL-1beta and IFN-gamma-mediated cell death in a concentration-dependent manner. Incubation with CRE induced a significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding which correlated well with reduced levels of the iNOS mRNA and protein. The molecular mechanism by which CRE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. The IL-1beta and IFN-gamma-stimulated RIN cells showed increases in NF-kappaB binding activity and p65 subunit levels in nucleus, and IkappaB alpha degradation in cytosol compared to unstimulated cells. Furthermore, the protective effects of CRE were verified via the observation of reduced NO generation and iNOS expression, and normal insulin-secretion responses to glucose in IL-1beta and IFN-gamma-treated islets.
我们之前证明，黄连提取物（CRE）通过抑制RINm5F（RIN）大鼠胰岛素瘤细胞的线粒体膜电位破坏和细胞色素c释放，预防了亚硝基-n-乙酰青霉胺诱导的凋亡细胞死亡。在本研究中，评估了CRE对细胞因子诱导的β细胞死亡的预防作用。浸润胰岛的免疫细胞产生的细胞因子是胰岛素依赖型糖尿病中β细胞破坏的关键介质。用IL-1β和IFN-γ处理RIN细胞导致细胞活力降低。CRE以浓度依赖的方式完全保护IL-1β和IFN-γ介导的细胞死亡。与CRE孵育可显著抑制IL-1β和IFN-γ诱导的一氧化氮（NO）产生，这一发现与iNOS mRNA和蛋白水平降低密切相关。CRE抑制iNOS基因表达的分子机制似乎涉及对NF-κB激活的抑制。与未刺激的细胞相比，IL-1β和IFN-γ刺激的RIN细胞显示出核内NF-κB结合活性和p65亚基水平增加，以及胞质中IκBα降解。此外，通过观察IL-1β和IFN-γ处理的胰岛中NO生成和iNOS表达降低以及对葡萄糖的正常胰岛素分泌反应，验证了CRE的保护作用。
