Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China.
Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China; Department of Nuclear Medicine, Fudan University Shanghai Cancer Center, Shanghai 200032, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Biomed Pharmacother. 2017 May;89:1310-1319. doi: 10.1016/j.biopha.2017.03.027. Epub 2017 Mar 17.
In view of the facts that tTG protein expression level and its enzyme activity increase in AD brains of both individuals and transgenic animals and compelling evidence of the involvement of inflammation in AD pathogenesis, tTG could be involved in the inflammation responses in the brain. In the present study, we examined the effects of the irreversible and the competitive inhibitor of tTG on the condition of lipopolysaccharide-induced mimic inflammation models in glial cells.
Western blot and tTG enzyme activity assay were applied to detect tTG and isopeptide protein levels and tTG enzyme activity. The production of nitric oxide and the expression levels of inducible nitric oxide synthase and cyclooxygenase-2 were determined by Griess Reagents and Western blot respectively to assess anti-inflammatory effects. Moreover, the activation of AKT/mTOR signaling pathway was determined to evaluate the underlying mechanism of anti-inflammatory response.
Irreversible and competitive inhibitor of tTG could ameliorate LPS-induced neuroinflammation in glial cells without cytotoxicity. Moreover, AKT/mTOR pathway may be involved in the anti-inflammatory response of tTG inhibitors. Therefore, NTU283 and Cystamine may alleviate inflammatory response in glial cells, probably through, at least partially, inhibiting the activation of AKT/mTOR signaling pathway.
Our study provided some clues that tTG inhibitors NTU283 and Cystamine might be potential candidates for the treatments of neuroinflammation-related diseases, although more studies needed for further exploration.
鉴于 tTG 蛋白表达水平及其酶活性在个体和转基因动物的 AD 大脑中增加，以及炎症参与 AD 发病机制的有力证据，tTG 可能参与大脑中的炎症反应。本研究探讨了不可逆和竞争性 tTG 抑制剂对神经胶质细胞中脂多糖诱导的模拟炎症模型的影响。
采用 Western blot 和 tTG 酶活性测定法检测 tTG 和异肽蛋白水平和 tTG 酶活性。通过格里斯试剂和 Western blot 分别测定一氧化氮的产生以及诱导型一氧化氮合酶和环加氧酶-2 的表达水平，以评估抗炎作用。此外，还测定了 AKT/mTOR 信号通路的激活情况，以评估抗炎反应的潜在机制。
tTG 的不可逆和竞争性抑制剂可改善 LPS 诱导的神经胶质细胞神经炎症，且无细胞毒性。此外，AKT/mTOR 通路可能参与了 tTG 抑制剂的抗炎反应。因此，NTU283 和半胱胺可能通过至少部分抑制 AKT/mTOR 信号通路的激活来减轻神经胶质细胞的炎症反应。
我们的研究提供了一些线索，表明 tTG 抑制剂 NTU283 和半胱胺可能是神经炎症相关疾病治疗的潜在候选药物，尽管需要进一步探索更多的研究。
