title: Substantial neuroprotection against K+ deprivation-induced apoptosis in primary cerebellar granule neurons by novel dimer bis(propyl)-cognitin via the activation of VEGFR-2 signaling pathway.
abstract: BACKGROUND
  Neuronal loss via apoptosis in CNS is the fundamental mechanism underlying various neurodegenerative diseases. Compounds with antiapoptotic property might have therapeutic effects for these diseases. In this study, bis(propyl)-cognitin (B3C), a novel dimer that possesses anti-AChE and anti-N-methyl-d-aspartate receptor activities, was investigated for its neuroprotective effect on K(+) deprivation-induced apoptosis in cerebellar granule neurons (CGNs).
  
  
  METHODS
  Cerebellar granule neurons were switched to K(+) deprived medium with or without B3C. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay, fluorescein diacetate (FDA)/propidium iodide (PI) staining, Hoechst staining, and DNA laddering assays were applied to detect cytotoxicity and apoptosis. Additionally, the expression of p-VEGFR-2, p-Akt, p-glycogen synthase kinase 3β (GSK3β), and p-extracellular signal-regulated kinase (ERK) was examined in CGNs.
  
  
  RESULTS
  Switching CGNs to K(+) deprived medium resulted in remarkable apoptosis, which could be substantially blocked by B3C treatment (IC50 , 0.37 μM). Moreover, a rapid decrease in p-Tyr1054-VEGFR-2 was observed after the switch. B3C significantly reversed the inhibition of p-Tyr1054-VEGFR-2 as well as Akt and ERK pathways. VEGFR-2 inhibitor PTK787/ZK222584, as well as PI3-K inhibitor LY294002 and MEK inhibitor PD98059, each abolished the neuroprotective effect of B3C.
  
  
  CONCLUSIONS
  Our results demonstrate that B3C blocks K(+) deprivation-induced apoptosis in CGNs through regulating VEGFR-2/Akt/GSK3β and VEGFR-2/ERK signaling pathways, providing a molecular insight into the therapeutic potential of B3C for the treatment of neurodegenerative diseases.
authors.affiliation: 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.
authors.forename: Sheng-Quan
authors.initials: SQ
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Cui
authors.forename: Da-Ping
authors.initials: DP
authors.lastname: Xu
authors.forename: Shing-Hung
authors.initials: SH
authors.lastname: Mak
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.forename: Chung-Lit
authors.initials: CL
authors.lastname: Choi
authors.forename: Yuan-Ping
authors.initials: YP
authors.lastname: Pang
authors.forename: Yi-Fan
authors.initials: YF
authors.lastname: Han
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013619:Tacrine / Q000031:analogs & derivatives* / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D018696:Neuroprotective Agents; C551529:bis(propyl)cognitin; D013619:Tacrine; D040301:Vascular Endothelial Growth Factor Receptor-2; D011188:Potassium
keywords: Akt; Apoptosis; Bis(propyl)-cognitin; Extracellular signal-regulated kinase; K+ deprivation; VEGFR-2