Mehanizam zaštitnog dejstva arilpiperazinskih liganada za dopaminske D2 receptore u azot monoksidom i 6-hidroksidopaminom izazvanoj smrti SH-SY5Y ćelija humanog neuroblastoma
Protective mechanism of arylpiperazine dopaminergic D2ligands on nitric oxide and 6-hydroxydopamine induced SH-SY5Y human neuroblastoma cell death
2012
Authors:
Tovilović-Kovačević, GordanaContributors
Anđus, PavleZogović, Nevena
Trajković, Vladimir
Tomić, Mirko
Document Type:
Doctoral thesis (Published version)
Metadata
Show full item recordAbstract:
We investigated the protective ability of 20 novel arylpiperazine-based
dopaminergic ligands against nitric oxide (NO) and dopaminergic neurotoxin
6-hydroxydopamine (6-OHDA)-mediated neurotoxicity. The most potent
neuroprotective compound against NO-induced toxicity was N-{4-[2-(4-phenylpiperazin-
1-yl)-ethyl]-phenyl}-picolinamide (arylpiperazine 6a), while N-{3-[2-(4-
phenyl-piperazin-1-yl)-ethyl]-phenyl}-picolinamide (arylpiperazine 6b) most
effectively protected SH-SY5Y human neuron-like cells from 6-OHDA-generated
oxidative injury. Arylpiperazine 6a diminished the proapoptotic action of NO donor
sodium nitroprusside (SNP) by decreasing superoxide anion content, mitochondrial
membrane depolarization, decline in intracellular adenozine-triphosphate (ATP)
content, caspase activation and subsequent phosphatydilserine externalization/DNA
fragmentation. The observed decrease of intracellular superoxide concentration was not
mediated by direct O2
-∙ scavenging. Arylpiperazine 6a did not interfere with NO
accumulation within the cell. The protective effect of arylpiperazine 6a in NO-induced
stress was associated with activation of anti-apoptotic (Akt) and the inhibition of
proapoptotic (JNK, ERK, AMPK) signaling pathways. A potential therapeutic value of
the arylpiperazine 6a in neurodegenerative/neuroinflammatory diseases prevention was
additionally supported by the ability of this arylpiperazine to protect SH-SY5Y neuronlike
cells from macrophage-derived NO. Similarly, arylpiperazine 6b prevented
6-OHDA-induced increase in superoxide anion content, mitochondrial membrane
depolarization and following apoptotic related events – caspase activation and DNA
fragmentation. The stabilization of 6-OHDA-disrupted mitochondrial membrane
potential by arylpiperazine 6b correlated with the decrease in intracellular superoxide
anion (O2
-∙) content, suggesting that decline in O2
-∙ concentration resulted from
mitohondrial membrane stabilization. Arylpiperazine 6b did not posses significant O2
-∙
scavenging ability. The mechanism underlying the protection provided by the
compound 6b was independent of JNK- and ERK-proapoptotic pathways, as
6-OHDA-provoked activation of these proapototic pathways was not modified by
arylpiperazine 6b. However, arylpiperazine 6b caused additional transient activation of
pro-survival Akt signaling pathway in 6-OHDA-treated cells, which probably
contributed to its anti-apoptotic effect. In addition to apoptosis, 6-OHDA induced
deleterious autophagy in SH-SY5Y cells by silencing the activity of mTOR, a key
autophagy inhibitor in the cell. Arylpiperazine 6b partialy prevented 6-OHDA-triggered
decrease of mTOR activity and autophagy in AMPK-independent manner. Although
both compounds showed partial agonist activity on hD2 receptors, their neuroprotective
action was independent of dopamine receptor binding, as it was not affected by the
high-affinity D1/D2 receptor blocker butaclamol (6a) or selective D2 receptor blocker
sulpiride (6b). These results support further study of arylpiperazines as potential
neuroprotective drugs.
Keywords:
Arylpiperazines; Neuroprotection; Nitric oxide; Oxidative stress; 6-hydroxydopamine; Apoptosis; Autophagy; Dopamine D2 receptorsSource:
University of Belgrade, Faculty of Biology, 2012, 1-116URI
http://eteze.bg.ac.rs/application/showtheses?thesesId=167https://fedorabg.bg.ac.rs/fedora/get/o:5401/bdef:Content/download
http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=1024560050
http://nardus.mpn.gov.rs/123456789/2081
https://radar.ibiss.bg.ac.rs/handle/123456789/2424