2020 Fiscal Year Research-status Report
Pyridoxamine could be a candidate drug for Parkinson`s disease: Mechanistic study to reduce dopamine-induced toxicity
| Project/Area Number |
19K07187
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| Research Institution | Tohoku University |
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Principal Investigator |
李 宣和 東北大学, 薬学研究科, 准教授 (60519776)
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| Co-Investigator(Kenkyū-buntansha) |
大江 知行 東北大学, 薬学研究科, 教授 (10203712)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | Pyridoxamine / Dopamine / Parkinson`s disease / Oxidative stress |
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| Outline of Annual Research Achievements |
Confirmation of the formation of PL-DA adduct in the intracellular-like conditions:
1. Dopamine (DA) was reacted with pyridoxamine (PM) in the presence of tyrosinase. Reaction time- and tyrosinase concentration-dependent decrease in DA and increase in pyridoxal (PL) and PL-DA adduct were observed. This result indicates that PM can scavenge DA quinone (DAQ) that is produced by enzymatic oxidation of DA.
2. DA was reacted with PM in the presence of glutathione (GSH). DAQ was formed via autooxidation and reacted with GSH as well as PM to produce GSH-DA and PL-DA adducts. The level of PL-DA adduct was increased in a PM dose-dependent manner, but not GSH-DA adduct. The same results were obtained when the reaction was carried out in the presence of GSH and tyrosinase.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
As planned, PL-DA adduct obtained from the reaction of DA with PM was characterized by MS/MS, UV, and NMR analyses. The mechanism for the adduct formation was proposed based on the reaction of DA analogs and PM. PM was shown to scavenge DAQ in the presence of tyrosinase and/or GSH, indicating that PM could inhibit DA-induced neurotoxicity by directly scavenging DAQ.
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| Strategy for Future Research Activity |
To investigate the inhibition effect of PM:
1. On the modification of α-synuclein (Syn) by DA: DA will be reacted with Syn to characterize the modification. Changes in levels of DA-modified Syn and PL-DA adduct will be monitored by adding PM.
2. On DA-induced aggregation of Syn: DA-induced aggregation of Syn will be detected by Thioflavin T fluorescence assay. Changes of aggregation status will be monitored by adding PM
3. On DA-induced oligomerization of Syn and cytotoxicity in human dopaminergic neuroblastoma cell line SH-SY5Y: DA-induced oligomerization of Syn will be detected by SDS page or Western blotting. Cytotoxicity will be evaluated by MTT assay. Changes in oligomerization/aggregation/cytotoxicity will be monitored by adding PM.
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