Indirubin-3-Oxime Effectively Prevents 6OHDA-Induced Neurotoxicity in PC12 Cells via Activating MEF2D Through the Inhibition of GSK3β.
Indirubin-3-oxime (I3O), a synthetic derivative of indirubin, was originally designed as potent inhibitors of cyclin-dependent kinases (CDKs) and glycogen synthase kinase 3β (GSK3β) for leukemia therapy. In the current study, we have shown, for the first time, that I3O prevented 6-hydroxydopamine (6OHDA)-induced neuronal apoptosis and intracellular reactive oxygen species accumulation in PC12 cells in a concentration-dependent manner. GSK3β inhibitors but not CDK5 inhibitors reduced the neurotoxicity induced by 6OHDA. Moreover, the activation of GSK3β was observed after 6OHDA treatment. Furthermore, 6OHDA substantially decreased the transcriptional activity of myocyte enhancer factor 2D (MEF2D), a transcription factor that plays an important role in dopaminergic neuron survival, and reduced nuclear localized MEF2D expression. Interestingly, indirubin-3-oxime and GSK3β inhibitors prevented 6OHDA-induced dysregulation of MEF2D. In addition, short hairpin RNA-mediated decrease of MEF2D expression significantly abolished the neuroprotective effects of indirubin-3-oxime. Collectively, our results strongly suggested that indirubin-3-oxime prevented 6OHDA-induced neurotoxicity via activating MEF2D, possibly through the inhibition of GSK3β. In view of the capability of indirubin-3-oxime to cross the blood-brain barrier, our findings further indicated that indirubin-3-oxime might be a novel drug candidate for neurodegenerative disorders, including Parkinson's disease in particular.
Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.|The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.|Institute of New Drug Research, Guangdong Province Key Laboratory of Pharmacodynamic, Constituents of Traditional Chinese Medicine & New Drug Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong, China.
Shengquan
S
Hu
Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.|The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
Wei
W
Cui
Institute of New Drug Research, Guangdong Province Key Laboratory of Pharmacodynamic, Constituents of Traditional Chinese Medicine & New Drug Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong, China.
Zaijun
Z
Zhang
Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.|The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
Shinghung
S
Mak
Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.|The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
Daping
D
Xu
National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou, China.
Gang
G
Li
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
Yuanjia
Y
Hu
Institute of New Drug Research, Guangdong Province Key Laboratory of Pharmacodynamic, Constituents of Traditional Chinese Medicine & New Drug Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong, China.
Yuqiang
Y
Wang
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
Mingyuen
M
Lee
Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China.
Karl Wahkeung
KW
Tsim
Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. shqhu@polyu.edu.hk.|The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China. shqhu@polyu.edu.hk.
Yifan
Y
Han
D000818:Animals; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D007211:Indoles / Q000494:pharmacology*; D064326:MEF2 Transcription Factors / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D016627:Oxidopamine / Q000633:toxicity; D010091:Oximes / Q000494:pharmacology*; D016716:PC12 Cells; D051381:Rats
D007211:Indoles; D064326:MEF2 Transcription Factors; C578045:MEF2D protein, rat; D018696:Neuroprotective Agents; D010091:Oximes; C474021:indirubin-3'-monoxime; D016627:Oxidopamine; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3
6OHDA; GSK3β; Indirubin-3-oxime; MEF2D; Neuroprotection; Parkinson’s disease