Abstract
The G protein-coupled serotonin 2A receptor (5-HT2AR) is a prominent target for atypical antipsychotic drugs, such as clozapine. Although clozapine is known to inhibit 5-HT2AR signaling through G protein-dependent mechanisms, it differs from classic GPCR antagonists, in that it also induces 5-HT2AR internalization and activates Akt signaling via a 5-HT2AR-mediated event. In this regard, clozapine may also be considered a functionally selective agonist. The cognate neurotransmitter at the 5-HT2AR, serotonin, also induces 5-HT2AR internalization and Akt phosphorylation. Serotonin promotes interactions with the scaffolding and regulatory protein, βarrestin2, which results in the recruitment and activation of Akt. These interactions prove to be critical for serotonin-induced, 5-HT2AR-mediated behavioral responses in mice. Herein, we sought to determine whether clozapine also utilizes βarrestin2-mediated mechanisms to induce 5-HT2AR signaling, and whether this interaction contributes to its behavioral effects in mice. We demonstrate that unlike serotonin, clozapine-mediated 5-HT2AR internalization and Akt phosphorylation is independent of receptor interactions with βarrestin2. Moreover, clozapine-mediated suppression of MK-801 and phencyclidine (PCP)-induced hyperlocomotion is βarrestin2 independent, although it is dependent upon Akt. These results demonstrate that pharmacologically oppositional ligands, serotonin and clozapine, utilize differential mechanisms to achieve the same 5-HT2AR-meadiated downstream events: Akt phosphorylation and receptor internalization. Although βarrestin2 has no effect on clozapine’s actions in vivo, Akt phosphorylation is required for clozapine’s efficacy in blocking MK-801- and PCP-induced models of schizophrenic behaviors in mice.
Similar content being viewed by others
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
References
Beaulieu JM, Sotnikova TD, Marion S, Lefkowitz RJ, Gainetdinov RR, Caron MG (2005). An Akt/beta-arrestin 2/PP2A signaling complex mediates dopaminergic neurotransmission and behavior. Cell 122: 261–273.
Beaulieu JM, Sotnikova TD, Yao WD, Kockeritz L, Woodgett JR, Gainetdinov RR et al (2004). Lithium antagonizes dopamine-dependent behaviors mediated by an AKT/glycogen synthase kinase 3 signaling cascade. Proc Natl Acad Sci USA 101: 5099–5104.
Beaulieu JM, Tirotta E, Sotnikova TD, Masri B, Salahpour A, Gainetdinov RR et al (2007). Regulation of Akt signaling by D2 and D3 dopamine receptors in vivo. J Neurosci 27: 881–885.
Bhatnagar A, Willins DL, Gray JA, Woods J, Benovic JL, Roth BL (2001). The dynamin-dependent, arrestin-independent internalization of 5-hydroxytryptamine 2A (5-HT2A) serotonin receptors reveals differential sorting of arrestins and 5-HT2A receptors during endocytosis. J Biol Chem 276: 8269–8277.
Bohn LM, Schmid CL (2010). Serotonin receptor signaling and regulation via beta-arrestins. Crit Rev Biochem Mol Biol 45: 555–566.
Corne SJ, Pickering RW (1967). A possible correlation between drug-induced hallucinations in man and a behavioural response in mice. Psychopharmacologia 11: 65–78.
Dwyer DS, Donohoe D (2003). Induction of hyperglycemia in mice with atypical antipsychotic drugs that inhibit glucose uptake. Pharmacol Biochem Behav 75: 255–260.
Emamian ES, Hall D, Birnbaum MJ, Karayiorgou M, Gogos JA (2004). Convergent evidence for impaired AKT1-GSK3beta signaling in schizophrenia. Nat Genet 36: 131–137.
Fribourg M, Moreno JL, Holloway T, Provasi D, Baki L, Mahajan R et al (2011). Decoding the signaling of a GPCR heteromeric complex reveals a unifying mechanism of action of antipsychotic drugs. Cell 147: 1011–1023.
Gainetdinov RR, Mohn AR, Caron MG (2001). Genetic animal models: focus on schizophrenia. Trends Neurosci 24: 527–533.
Gleason SD, Shannon HE (1997). Blockade of phencyclidine-induced hyperlocomotion by olanzapine, clozapine and serotonin receptor subtype selective antagonists in mice. Psychopharmacology 129: 79–84.
Gonzalez-Maeso J, Weisstaub NV, Zhou M, Chan P, Ivic L, Ang R et al (2007). Hallucinogens recruit specific cortical 5-HT(2A) receptor-mediated signaling pathways to affect behavior. Neuron 53: 439–452.
Higgins GA, Enderlin M, Haman M, Fletcher PJ (2003). The 5-HT2A receptor antagonist M100,907 attenuates motor and 'impulsive-type' behaviours produced by NMDA receptor antagonism. Psychopharmacology 170: 309–319.
Ikeda M, Iwata N, Suzuki T, Kitajima T, Yamanouchi Y, Kinoshita Y et al (2004). Association of AKT1 with schizophrenia confirmed in a Japanese population. Biological psychiatry 56: 698–700.
Jones CA, Watson DJ, Fone KC (2011). Animal models of schizophrenia. Br J Pharmacol 164: 1162–1194.
Lu XH, Bradley RJ, Dwyer DS (2004). Olanzapine produces trophic effects in vitro and stimulates phosphorylation of Akt/PKB, ERK1/2, and the mitogen-activated protein kinase p38. Brain Res 1011: 58–68.
Lukasiewicz S, Polit A, Kedracka-Krok S, Wedzony K, Mackowiak M, Dziedzicka-Wasylewska M (2010). Hetero-dimerization of serotonin 5-HT(2A) and dopamine D(2) receptors. Biochim Biophys Acta 1803: 1347–1358.
Masri B, Salahpour A, Didriksen M, Ghisi V, Beaulieu JM, Gainetdinov RR et al (2008). Antagonism of dopamine D2 receptor/beta-arrestin 2 interaction is a common property of clinically effective antipsychotics. Proc Natl Acad Sci USA 105: 13656–13661.
Matsubara S, Meltzer HY (1989). Effect of typical and atypical antipsychotic drugs on 5-HT2 receptor density in rat cerebral cortex. Life Sci 45: 1397–1406.
McOmish CE, Lira A, Hanks JB, Gingrich JA (2012). Clozapine-induced locomotor suppression is mediated by 5-HT(2A) receptors in the forebrain. Neuropsychopharmacology 37: 2747–2755.
Meltzer HY (2012). Clozapine: balancing safety with superior antipsychotic efficacy. Clin Schizophr Relat Psychoses 6: 134–144.
Meltzer HY (2013). Update on typical and atypical antipsychotic drugs. Annu Rev Med 64: 393–406.
Meltzer HY, Arvanitis L, Bauer D, Rein W (2004). Placebo-controlled evaluation of four novel compounds for the treatment of schizophrenia and schizoaffective disorder. Am J Psychiatry 161: 975–984.
Meltzer HY, Huang M (2008). In vivo actions of atypical antipsychotic drug on serotonergic and dopaminergic systems. Prog Brain Res 172: 177–197.
Meltzer HY, Massey BW (2011). The role of serotonin receptors in the action of atypical antipsychotic drugs. Curr Opin Pharmacol 11: 59–67.
Millan MJ, Brocco M, Gobert A, Joly F, Bervoets K, Rivet J et al (1999). Contrasting mechanisms of action and sensitivity to antipsychotics of phencyclidine versus amphetamine: importance of nucleus accumbens 5-HT2A sites for PCP-induced locomotion in the rat. Eur J Neurosci 11: 4419–4432.
Moreno JL, Holloway T, Umali A, Rayannavar V, Sealfon SC, Gonzalez-Maeso J (2013). Persistent effects of chronic clozapine on the cellular and behavioral responses to LSD in mice. Psychopharmacology 225: 217–226.
Peroutka SJ, Snyder SH (1980). Long-term antidepressant treatment decreases spiroperidol-labeled serotonin receptor binding. Science 210: 88–90.
Rajagopal S, Rajagopal K, Lefkowitz RJ (2010). Teaching old receptors new tricks: biasing seven-transmembrane receptors. Nat Rev Drug Discov 9: 373–386.
Raote I, Bhattacharyya S, Panicker MM (2013). Functional selectivity in serotonin receptor 2A (5-HT2A) endocytosis, recycling, and phosphorylation. Mol Pharmacol 83: 42–50.
Roth BL, Sheffler DJ, Kroeze WK (2004). Magic shotguns versus magic bullets: selectively non-selective drugs for mood disorders and schizophrenia. Nat Rev Drug Discov 3: 353–359.
Schmid CL, Bohn LM (2010). Serotonin, but not N-methyltryptamines, activates the serotonin 2A receptor via a ss-arrestin2/Src/Akt signaling complex in vivo. J Neurosci 30: 13513–13524.
Schmid CL, Raehal KM, Bohn LM (2008). Agonist-directed signaling of the serotonin 2A receptor depends on beta-arrestin-2 interactions in vivo. Proc Natl Acad Sci USA 105: 1079–1084.
Sutton LP, Rushlow WJ (2011). The effects of neuropsychiatric drugs on glycogen synthase kinase-3 signaling. Neuroscience 199: 116–124.
Tang AH, Franklin SR, Himes CS, Smith MW, Tenbrink RE (1997). PNU-96415E, a potential antipsychotic agent with clozapine-like pharmacological properties. J Pharmacol Exp Ther 281: 440–447.
Urban JD, Clarke WP, von Zastrow M, Nichols DE, Kobilka B, Weinstein H et al (2007). Functional selectivity and classical concepts of quantitative pharmacology. J Pharmacol Exp Ther 320: 1–13.
Weeks KR, Dwyer DS, Aamodt EJ (2011). Clozapine and lithium require Caenorhabditis elegans beta-arrestin and serum- and glucocorticoid-inducible kinase to affect Daf-16 (FOXO) localization. J Neurosci Res 89: 1658–1665.
Weiner DM, Burstein ES, Nash N, Croston GE, Currier EA, Vanover KE et al (2001). 5-hydroxytryptamine2A receptor inverse agonists as antipsychotics. J Pharmacol Exp Ther 299: 268–276.
Williams AA, Ingram WM, Levine S, Resnik J, Kamel CM, Lish JR et al (2012). Reduced levels of serotonin 2A receptors underlie resistance of Egr3-deficient mice to locomotor suppression by clozapine. Neuropsychopharmacology 37: 2285–2298.
Willins DL, Alsayegh L, Berry SA, Backstrom JR, Sanders-Bush E, Friedman L et al (1998). Serotonergic antagonist effects on trafficking of serotonin 5-HT2A receptors in vitro and in vivo. Ann N Y Acad Sci 861: 121–127.
Willins DL, Berry SA, Alsayegh L, Backstrom JR, Sanders-Bush E, Friedman L et al (1999). Clozapine and other 5-hydroxytryptamine-2A receptor antagonists alter the subcellular distribution of 5-hydroxytryptamine-2A receptors in vitro and in vivo. Neuroscience 91: 599–606.
Xi D, Li YC, Snyder MA, Gao RY, Adelman AE, Zhang W et al (2011). Group II metabotropic glutamate receptor agonist ameliorates MK801-induced dysfunction of NMDA receptors via the Akt/GSK-3beta pathway in adult rat prefrontal cortex. Neuropsychopharmacology 36: 1260–1274.
Yadav PN, Kroeze WK, Farrell MS, Roth BL (2011). Antagonist functional selectivity: 5-HT2A serotonin receptor antagonists differentially regulate 5-HT2A receptor protein level in vivo. J Pharmacol Exp Ther 339: 99–105.
Acknowledgements
The original βarrestin2-KO mouse colony was provided by Dr Robert J Lefkowitz, MD, Duke University, HHMI, and has been maintained by the Bohn laboratory for 10 years.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Schmid, C., Streicher, J., Meltzer, H. et al. Clozapine Acts as an Agonist at Serotonin 2A Receptors to Counter MK-801-Induced Behaviors through a βArrestin2-Independent Activation of Akt. Neuropsychopharmacol 39, 1902–1913 (2014). https://doi.org/10.1038/npp.2014.38
Received:
Revised:
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1038/npp.2014.38
This article is cited by
-
The role of serotonin neurotransmission in rapid antidepressant actions
Psychopharmacology (2022)
-
Dopaminergic control of ADAMTS2 expression through cAMP/CREB and ERK: molecular effects of antipsychotics
Translational Psychiatry (2019)
-
Role of mGlu2 in the 5-HT2A receptor-dependent antipsychotic activity of clozapine in mice
Psychopharmacology (2018)
-
Amelioration of experimental autoimmune encephalomyelitis by clozapine is not associated with defective CD4 T cell responses
Journal of Neuroinflammation (2017)
-
Discovery of new GPCR ligands to illuminate new biology
Nature Chemical Biology (2017)
