Up-regulation of glial cell line-derived neurotrophic factor by newly synthesized cyclopentenone derivatives : Studies on cellular mechanisms in vitro and effectiveness in vivo

新合成的（芳基硫代）环戊烯酮衍生物（GIF-0642, GIF-0643）通过抑制线粒体中caspase的激活和细胞色素c的释放来抑制锰诱导的PC12细胞凋亡。GIF-0642和GIF-0643也对氧化应激诱导的小鼠海马HT22细胞和C6胶质瘤细胞死亡具有神经保护作用。GIF-0642和GIF-0643结合过氧化物酶体增殖物激活受体-γ(PPARγ)和活化的PPARγ- rxr异源二聚体。此外，这些化合物还能诱导C6胶质瘤细胞中GDNF、BDNF和神经生长因子（NGF）的基因表达。GIF-0642和GIF-0643刺激MAP激酶途径中各种信号分子的磷酸化。我们合成了生物素化（芳基硫代）环戊烯酮，利用下拉实验研究了MAP激酶途径中各种信号分子与化合物之间的直接相互作用。结果表明（芳硫代）环戊烯酮直接与Raf分子结合。另一方面，小鼠腹腔注射GIF-0642不能刺激大脑中的神经营养因子，如GDNF、BDNF和NGF。尚需进一步研究芳基硫代环戊烯酮对体内神经营养因子表达的影响。这些包括化合物的剂量、溶解所用化合物的溶剂和给药方法。

Newly synthesized(arylthio) cyclopentenone derivatives(GIF-0642, GIF-0643) suppressed manganese-induced apoptosis in PC12 cells by inhibiting caspase activation and cytochrome c release from mitochondria. GIF-0642 and GIF-0643 were also neuroprotective against oxidative stress-induced cell death in mouse hippocampal HT22 cells and C6 glioma cells. GIF-0642 and GIF-0643 bound to peroxisome proliferator-activated receptor-γ(PPARγ) and activated PPARγ-RXR heterodimers. Furthermore, these compounds induced gene expression of GDNF, BDNF and nerve growth factor(NGF) in C6 glioma cells. GIF-0642 and GIF-0643 stimulated phosphorylation of various signaling molecules in the MAP kinase pathway. We synthesized biotinylated(arylthio) cyclopentenones to study direct interaction between various signaling molecules in the MAP kinase pathway and chemical compounds using a pull-down assay. The results suggest that(arylthio) cyclopentenones directly bind to Raf molecule. On the other hand, intraperitoneal administration of GIF-0642 in mice failed to stimulate neurotrophic factors such as GDNF, BDNF, and NGF in the brain. Further study is required to determine the effects of(arylthio) cyclopentenones on the expression of neurotrophic factors in vivo. These include dosage of chemical compounds, solvents for dissolving chemical compounds to use, and the method of administration.