LDN-212320(OSU-0212320) is a glutamate transporter EAAT2 activator; enhances EAAT2 levels by >6 fold at concentrations< 5 μM after 24 h.IC50 value: 1.83 uM(EC50) [2]Target: EAAT2 activatorin vitro: LDN/OSU-0212320 increased EAAT2 protein levels in a dose-dependent(EC50=1.83 ± 0.27 μM) and time-dependent manner. LDN/OSU-0212320 increased EAAT2 protein levels and glutamate uptake function, but did not affect EAAT1 or EAAT3 protein levels. LDN/OSU-0212320 treatment markedly prevented neuronal loss and degeneration, as assessed by MAP2 immunostaining [2]. in vivo: After a single i.p. 40-mg/kg dose of LDN/OSU-0212320, EAAT2 protein levels and associated glutamate uptake increased by approximately 1.5- to 2-fold at 2 hours and by approximately 2- to 3-fold between 8 and 24 hours after injection. Even 72 hours after injection, an approximately 1.5-fold increase in EAAT2 protein levels could still be detected (data not shown). In addition, we found that LDN/OSU-0212320–induced EAAT2 protein levels and glutamate uptake were dose dependent [2].Small-molecule activator of glutamate transporter EAAT2 translation provides neuroprotectionBy Kong, Qiongman; Chang, Ling-Chu; Takahashi, Kou; Liu, Qibing; Schulte, Delanie A.; Lai, Liching; Ibabao, Brian; Lin, Yuchen; Stouffer, Nathan; Das Mukhopadhyay, Chitra; et alFrom Journal of Clinical Investigation (2014), 124(3), 1255-1267. Structure-activity relationship study of pyridazine derivatives as glutamate transporter EAAT2 activatorsBy Xing, Xuechao; Chang, Ling-Chu; Kong, Qiongman; Colton, Craig K.; Lai, Liching; Glicksman, Marcie A.; Lin, Chien-Liang Glenn; Cuny, Gregory D. From Bioorganic & Medicinal Chemistry Letters (2011), 21(19), 5774-5777.

References:
[1]. Xing X, et al. Structure-activity relationship study of pyridazine derivatives as glutamate transporter EAAT2 activators. Bioorg Med Chem Lett. 2011 Oct 1;21(19):5774-7.
[2]. Kong Q, et al. Small-molecule activator of glutamate transporter EAAT2 translation provides neuroprotection. J Clin Invest. 2014 Mar;124(3):1255-67.