AR-A014418

IC50: 104 ± 27 nM

Glycogen synthase kinase 3 (GSK3) is a serine/threonine kinase that has been implicated in pathological conditions such as diabetes and Alzheimer’s disease (AD). AR-A014418 is a selective GSK-3 inhibitor.

In vitro: ARA014418 acted as an ATP-competitive manner and did not significantly inhibit cdk2 or cdk5 or 26 other kinases demonstrating high specificity for GSK3. AR-A014418 inhibited tau phosphorylation at a GSK3-specific site (Ser-396) in cells stably expressing human four-repeat tau protein [1].

In vivo: ARA014418 induced behavioural changes that were consistent with the effects of antidepressant drugs. Subacute intraperitoneal injections of AR-A014418 reduced immobility time in rats exposed to the forced swim test, which was a well-established model for antidepressant efficacy. Moreover, the specificity of this effect was supported by our finding that AR-A014418 decreased spontaneous as well as amphetamine-induced activity [2].

Clinical trial: currently no clinical data were available

References:
[1] Bhat R, Xue Y, Berg S, Hellberg S, Orm? M, Nilsson Y, Rades?ter AC, Jerning E, Markgren PO, Borgeg?rd T, Nyl?f M, Giménez-Cassina A, Hernández F, Lucas JJ, Díaz-Nido J, Avila J.  Structural insights and biological effects of glycogen synthase kinase 3-specific inhibitor AR-A014418. J Biol Chem. 2003;278(46):45937-45.
[2] Gould TD, Einat H, Bhat R, Manji HK.  AR-A014418, a selective GSK-3 inhibitor, produces antidepressant-like effects in the forced swim test. Int J Neuropsychopharmacol. 2004;7(4):387-90.

Towards the preparation of radiolabeled 1-aryl-3-benzyl ureas: Radiosynthesis of [(11)C-carbonyl] AR-A014418 by [(11)C]CO(2) fixation.[Pubmed:22321216]

Bioorg Med Chem Lett. 2012 Mar 1;22(5):2099-101.

The highly selective glycogen synthase kinase-3 (GSK-3) inhibitor N-(4-methoxybenzyl)-N'-(5-nitro-1,3-thiazol-2-yl)urea (AR-A014418) was radiolabeled with carbon-11 ((11)C; half-life=20.4min) at the urea moiety via [(11)C]CO(2) fixation. Reaction of [(11)C]CO(2) with 4-methoxybenzylamine in the presence of a CO(2) fixating base was followed by dehydration with POCl(3) and addition of 2-amino-5-nitrothiazole to prepare [(11)C-carbonyl] AR-A014418. This reaction resulted in an 8% uncorrected radiochemical yield, based on [(11)C]CO(2), with high specific activity (4Ci/mumol) within 30min. An in vitro GSK-3beta enzyme activity assay revealed that AR-A014418 (K(i)=770nM) is not as potent as previously claimed. The [(11)C]CO(2) fixation methodology described herein should prove generally applicable to preparing 1-aryl-3-benzyl-[(11)C-carbonyl] ureas as radiotracers for positron emission tomography.

Glycogen synthase kinase-3beta (GSK-3beta) inhibitors AR-A014418 and B6B3O prevent human immunodeficiency virus-mediated neurotoxicity in primary human neurons.[Pubmed:19688630]

J Neurovirol. 2009 Sep;15(5-6):434-8.

Glycogen synthase kinase-3beta (GSK3beta) role in human immunodeficiency virus(HIV)-associated neurodegeneration has been evidenced by previous investigations. In this study, we investigated the specificity of two GSK3beta-specific inhibitors, AR-A014418 (A) and B6B30 (B) to prevent direct neurotoxicity in primary human neurons exposed to HIV (BaL). Neurons were exposed to HIV (500 pg/ml) for 12-h and 6-day periods in the presence and absence of A (1 microM, 100 nM, 10 nM) and B (50 nM, 5 nM, 500 pM) to investigate acute and ongoing mechanisms of HIV neurotoxicity. Using an lactate dehydrogenase (LDH) assay to assess cytotoxicity, we observed a significant neurotoxic effect of HIV from control values (P < .01) that was not restored via coexposures of all concentrations of A and B. Additionally, no change in LDH levels were observed after 6 days. However, activity of the acute proapoptotic markers caspases 3 and 7 using a luminescence assay were measured and found to be increased by exposure to HIV (BaL) compared to controls (P = .022). This effect was ameliorated via coexposure to all concentrations of A and 50 nM B after 12 h (P < .01) and to all concentrations of A and B after 6 days (P < .01). Overall, the results from this study provide further evidence for the ability of GSK3beta inhibition to be neuroprotective against HIV-associated neurotoxicity by reducing HIV associated procaspase induction. These data support a role for GSK3beta as a potential therapeutic target and may have important clinical implications for treatment of HIV-associated neurocognitive disorder.

The antinociceptive effects of AR-A014418, a selective inhibitor of glycogen synthase kinase-3 beta, in mice.[Pubmed:20705523]

J Pain. 2011 Mar;12(3):315-22.

UNLABELLED: We investigated the antinociceptive effects of AR-A014418, a selective inhibitor of glycogen synthase kinase-3beta (GSK-3beta) in mice. A 30-minute pretreatment with AR-A014418 (.1 and 1 mg/kg, intraperitoneal [ip]) inhibited nociception induced by an ip injection of acetic acid. AR-A014418 pretreatment (.1 and .3 mg/kg, ip) also decreased the late (inflammatory) phase of formalin-induced licking, without affecting responses of the first (neurogenic) phase. In a different set of experiments, AR-A014418 (.1-10 mug/site) coinjected intraplantarly (ipl) with formalin inhibited the late phase of formalin-induced nociception. Furthermore, AR-A014418 administration (1 and 10 ng/site, intrathecal [it]) inhibited both phases of formalin-induced licking. In addition, AR-A014418 coinjection (10 ng/site, it) inhibited nociception induced by glutamate, N-methyl-D-aspartate (NMDA), (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) by 47 +/- 12%, 48 +/- 11%, 31 +/- 8%, 46 +/- 13%, and 44 +/- 11%, respectively. In addition, a 30-minute pretreatment with NP031115 (3 and 10 mg/kg, ip), a different GSK-3 beta inhibitor, also attenuated the late phase of formalin-induced nociception. Collectively, these results provide convincing evidence that AR-A014418, given by local, systemic, and central routes, produces antinociception in several mouse models of nociception. The AR-A014418-dependent antinociceptive effects were induced by modulation of the glutamatergic system through metabotropic and ionotropic (NMDA) receptors and the inhibition of the cytokine (TNF-alpha and IL-1beta) signaling. PERSPECTIVE: These results suggest that GSK-3beta may be a novel pharmacological target for the treatment of pain.

AR-A014418 as a glycogen synthase kinase-3 inhibitor: anti-apoptotic and therapeutic potential in experimental spinal cord injury.[Pubmed:23116585]

Neurocirugia (Astur). 2013 Jan-Feb;24(1):22-32.

OBJECTIVES: We aimed to investigate the effects of AR-A014418, a strong inhibitor specific to GSK-3beta, on neuronal apoptosis and neuroprotection in the traumatic SCI model. MATERIALS AND METHODS: In this study, three groups were generated from 36 Wistar rats; (1) control, (2) spinal cord trauma group created by clip compression technique after laminectomy, and (3) AR-A014418 (4mg/kg, i.p., DMSO) treatment group after laminectomy and spinal cord trauma. The TUNEL assay for apoptosis detection, immunohistochemical staining for bax and TGF-beta were applied in spinal cord tissues. For light microscopic examination, necrotic, and apoptotic cells were counted, and PMNL counting was applied to detect inflammation. Functional recovery was tested by field locomotor test in the 3rd and 7th days following surgery. RESULTS: In the trauma group, diffuse hemorrhage, cavitation, necrosis and edematous regions, degeneration in motor neurons and leukocyte infiltration were observed in gray matter. In the AR-A014418-treated groups, healthy cells were observed in more places compared to the trauma groups, however, cavitation, hemorrhagic, and edematous areas were seen in gray matter. In the AR-A014418-treatment groups, the number of apoptotic cells in the 3rd and 7th days (respectively; p<0.05, p<0.01), were significantly decreased compared to the trauma groups, as were the levels of bax (p<0.01) and TGF-beta 1 immunoreactivity. Results of the locomotor test were significantly increased in the treatment group (p<0.001) as compared to the trauma group. CONCLUSIONS: In this experimental spinal cord trauma model study neural apoptosis was significantly triggered in secondary damage developed after trauma, however, neurological healing was expedited by preventing mitochondrial apoptosis and reducing the inflammation by the potent inhibitor AR-A014418, which is GSK-3beta selective.

AR-A014418, a selective GSK-3 inhibitor, produces antidepressant-like effects in the forced swim test.[Pubmed:15315719]

Int J Neuropsychopharmacol. 2004 Dec;7(4):387-90.

The mechanism by which lithium exerts either its anti-manic or antidepressant effects remains to be fully elucidated. Although lithium inhibits the enzyme glycogen synthase kinase-3 (GSK-3) at concentrations that are relevant for treatment of bipolar disorder, it is unclear whether GSK-3-related mechanisms are responsible for its therapeutic effects in the treatment of this disease. We report that AR-A014418 (a selective GSK-3 inhibitor) induces behavioural changes that are consistent with the effects of antidepressant medications. Subacute intraperitoneal injections of AR-A014418 reduced immobility time in rats exposed to the forced swim test, a well-established model for antidepressant efficacy. In addition, the specificity of this effect is supported by our finding that AR-A014418 decreased spontaneous as well as amphetamine-induced activity. Taken together, these data support the hypothesis that lithium may exert its antidepressant effects through inhibition of GSK-3, and that novel small-molecule GSK-3 inhibitors may be useful for the treatment of bipolar disorder and depression.

Glycogen synthase kinase-3 inhibitor AR-A014418 suppresses pancreatic cancer cell growth via inhibition of GSK-3-mediated Notch1 expression.[Pubmed:26147011]

HPB (Oxford). 2015 Sep;17(9):770-6.

BACKGROUND: Glycogen synthase kinase-3 (GSK-3) can act as either a tumour promoter or suppressor by its inactivation depending on the cell type. There are conflicting reports on the roles of GSK-3 isoforms and their interaction with Notch1 in pancreatic cancer. It was hypothesized that GSK-3alpha stabilized Notch1 in pancreatic cancer cells thereby promoting cellular proliferation. METHODS: The pancreatic cancer cell lines MiaPaCa2, PANC-1 and BxPC-3, were treated with 0-20 muM of AR-A014418 (AR), a known GSK-3 inhibitor. Cell viability was determined by the MTT assay and Live-Cell Imaging. The levels of Notch pathway members (Notch1, HES-1, survivin and cyclinD1), phosphorylated GSK-3 isoforms, and apoptotic markers were determined by Western blot. Immunoprecipitation was performed to identify the binding of GSK-3 specific isoform to Notch1. RESULTS: AR-A014418 treatment had a significant dose-dependent growth reduction (P < 0.001) in pancreatic cancer cells compared with the control and the cytotoxic effect is as a result of apoptosis. Importantly, a reduction in GSK-3 phosphorylation lead to a reduction in Notch pathway members. Overexpression of active Notch1 in AR-A014418-treated cells resulted in the negation of growth suppression. Immunoprecipitation analysis revealed that GSK-3alpha binds to Notch1. CONCLUSIONS: This study demonstrates for the first time that the growth suppressive effect of AR-A014418 on pancreatic cancer cells is mainly mediated by a reduction in phosphorylation of GSK-3alpha with concomitant Notch1 reduction. GSK-3alpha appears to stabilize Notch1 by binding and may represent a target for therapeutic development. Furthermore, downregulation of GSK-3 and Notch1 may be a viable strategy for possible chemosensitization of pancreatic cancer cells to standard therapeutics.

Structural insights and biological effects of glycogen synthase kinase 3-specific inhibitor AR-A014418.[Pubmed:12928438]

J Biol Chem. 2003 Nov 14;278(46):45937-45.

Glycogen synthase kinase 3 (GSK3) is a serine/threonine kinase that has been implicated in pathological conditions such as diabetes and Alzheimer's disease. We report the characterization of a GSK3 inhibitor, AR-A014418, which inhibits GSK3 (IC50 = 104 +/- 27 nM), in an ATP-competitive manner (Ki = 38 nM). AR-A014418 does not significantly inhibit cdk2 or cdk5 (IC50 > 100 microM) or 26 other kinases demonstrating high specificity for GSK3. We report the co-crystallization of AR-A014418 with the GSK3beta protein and provide a description of the interactions within the ATP pocket, as well as an understanding of the structural basis for the selectivity of AR-A014418. AR-A014418 inhibits tau phosphorylation at a GSK3-specific site (Ser-396) in cells stably expressing human four-repeat tau protein. AR-A014418 protects N2A neuroblastoma cells against cell death mediated by inhibition of the phosphatidylinositol 3-kinase/protein kinase B survival pathway. Furthermore, AR-A014418 inhibits neurodegeneration mediated by beta-amyloid peptide in hippocampal slices. AR-A014418 may thus have important applications as a tool to elucidate the role of GSK3 in cellular signaling and possibly in Alzheimer's disease. AR-A014418 is the first compound of a family of specific inhibitors of GSK3 that does not significantly inhibit closely related kinases such as cdk2 or cdk5.

GSK3beta signalling: casting a wide net in Alzheimer's disease.[Pubmed:12566926]

Neurosignals. 2002 Sep-Oct;11(5):251-61.

Glycogen synthase kinase-3beta (GSK3beta) is a kinase that plays a pivotal role in numerous cellular functions from modulation of microtubule dynamics and cell death. It also affects higher functions such as cognition and mood. Deregulation of GSK3beta activity in the adult brain is implicated in several CNS disorders, such as affective disorders, schizophrenia, stroke and neurodegenerative diseases, such as Alzheimer's disease (AD). In AD, GSK3beta has a major role in microtubule stability by its ability to phosphorylate the microtubule associated protein tau. The present review focuses on recent developments in the understanding of GSK3beta with an emphasis on events likely to be critical to the pathophysiology of AD.