Shenzhen Hospital of Southern Medical University, Shenzhen, Guangdong Province, 518033 China.
Chin J Integr Med. 2010 Feb;16(1):41-9. doi: 10.1007/s11655-010-0041-z. Epub 2010 Feb 4.
Changes of the internal and external cellular environments can induce calcium homeostasis disorder and unfolded protein aggregation in the endoplasmic reticulum (ER). This ER function disorder is called endoplasmic reticulum stress (ERS). Severe long-term ERS can trigger the ER apoptosis signaling pathway, resulting in cell apoptosis and organism injury. Recent researches revealed that ERS-induced cell death was involved in the neurocyte retrogradation in the progress of neuron degenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease and so on. Therefore, the protection effect of the traditional Chinese drug-Tiantai No. 1 (1) on the ERS injury of AD was investigated at the molecular gene level in this study with a view to explore the gene pharmacodynamic actions and mechanisms of this drug.
Primarily cultured marrow mesenchymal stem cells (MSCs) of rats were treated by tunicamycin (TM) in order to induce ERS. RT-PCR, fluorescence immunocytochemistry and Western blot techniques were used to determine the mRNA and protein expression levels of the protective stress protein-ER molecular chaperones GRP78 and GRP94 (which would assist cells to resist cellular stress injury), and to determine the mRNA and protein expression levels of apoptosis promoting molecule Caspase-12 on the membrane of the ER, respectively.
Protein expression levels of GRP78 and GRP94 were significantly increased in the TM-induced MSCs, and the mRNA level of Caspase-12 was also remarkably increased in the TM-induced MSCs (P<0.05). All these proved that the ERS model was successfully established by TM in MSC. Meanwhile, the mRNA and protein levels of GRP78 and GRP94 were all significantly increased compared with the model group (P<0.05 or P<0.01) after MSCs were treated with Tiantai No.1 while the mRNA and protein expression levels of Caspase-12 were significantly decreased compared with the model group (P<0.05 or P<0.01). This effect showed a dose dependent manner.
Tiantai No.1 might attenuate the cell apoptosis induced by ERS injury, and thus protect the neurons against AD.
细胞内外环境的变化会导致内质网（ER）中钙稳态紊乱和未折叠蛋白聚集。这种 ER 功能障碍称为内质网应激（ERS）。严重的长期 ERS 会触发 ER 凋亡信号通路，导致细胞凋亡和组织损伤。最近的研究表明，ERS 诱导的细胞死亡参与了神经元退行性疾病（如阿尔茨海默病（AD）、帕金森病等）中神经细胞逆行的过程。因此，本研究从分子基因水平探讨了中药天台 1 号（1）对 AD 中 ERS 损伤的保护作用，以期探讨该药物的基因药效作用和机制。
用衣霉素（TM）处理原代培养的大鼠骨髓间充质干细胞（MSCs），诱导 ERS。采用 RT-PCR、荧光免疫细胞化学和 Western blot 技术，分别检测保护性应激蛋白-ER 分子伴侣 GRP78 和 GRP94 的 mRNA 和蛋白表达水平（有助于细胞抵抗细胞应激损伤），以及内质网膜上促凋亡分子 Caspase-12 的 mRNA 和蛋白表达水平。
TM 诱导的 MSC 中 GRP78 和 GRP94 的蛋白表达水平显著升高，TM 诱导的 MSC 中 Caspase-12 的 mRNA 水平也显著升高（P<0.05）。所有这些都证明 TM 成功地在 MSC 中建立了 ERS 模型。同时，与模型组相比，天台 1 号处理后的 MSC 中 GRP78 和 GRP94 的 mRNA 和蛋白水平均显著升高（P<0.05 或 P<0.01），而 Caspase-12 的 mRNA 和蛋白表达水平则显著降低（P<0.05 或 P<0.01）。这种作用呈剂量依赖性。
天台 1 号可能减轻 ERS 损伤引起的细胞凋亡，从而保护神经元免受 AD 的侵害。
