Astrocytes are the most abundant cell type in the human brain and are important regulators of several critical cellular functions, including synaptic transmission. Although astrocytes are known to play a central role in the etiology and pathophysiology of schizophrenia, little is known about their potential involvement in clinical response to the antipsychotic clozapine. Moreover, astrocytes display a remarkable degree of morphological diversity, but the potential contribution of astrocytic subtypes to disease biology and drug response has received little attention. Here, we used state-of-the-art human induced pluripotent stem cell (hiPSC) technology to derive a morphological subtype of astrocytes from healthy individuals and individuals with schizophrenia, including responders and nonresponders to clozapine. Using functional assays and transcriptional profiling, we identified a distinct gene expression signature highly specific to schizophrenia as shown by disease association analysis of more than 10 000 diseases. We further found reduced levels of both glutamate and the NMDA receptor coagonist d-serine in subtype astrocytes derived from schizophrenia patients, and that exposure to clozapine only rescued this deficiency in cells from clozapine responders, providing further evidence that d-serine in particular, and NMDA receptor-mediated glutamatergic neurotransmission in general, could play an important role in disease pathophysiology and clozapine action. Our study represents a first attempt to explore the potential contribution of astrocyte diversity to schizophrenia pathophysiology using a human cellular model. Our findings suggest that specialized subtypes of astrocytes could be important modulators of disease pathophysiology and clinical drug response, and warrant further investigations.

Bioinformatics in Translational Research RECETOX and IBA Masaryk University Brno Czech Republic

Department of Biology Faculty of Medicine Masaryk University Brno Czech Republic

Department of Medical Genetics Oslo University Hospital Oslo Norway

Department of Psychiatry Faculty of Medicine and University Hospital Brno Brno Czech Republic

Division of Mental Health and Addiction Oslo University Hospital Oslo Norway

NORMENT Department of Clinical Science University of Bergen Bergen Norway

NORMENT Institute of Clinical Medicine University of Oslo Oslo Norway

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Vasile F, Dossi E, Rouach N. Human astrocytes: structure and functions in the healthy brain. Brain Struct Funct. 2017;222(5):2017–2029. PubMed PMC

Uno Y, Coyle JT. Glutamate hypothesis in schizophrenia. Psychiatry Clin Neurosci. 2019;73(5):204–215. PubMed

Kim R, Healey KL, Sepulveda-Orengo MT, Reissner KJ. Astroglial correlates of neuropsychiatric disease: from astrocytopathy to astrogliosis. Prog Neuropsychopharmacol Biol Psychiatry. 2018;87(Pt A):126–146. PubMed PMC

Tarasov VV, Svistunov AA, Chubarev VN, et al. . Alterations of astrocytes in the context of schizophrenic dementia. Front Pharmacol. 2019;10:1612. PubMed PMC

Khakh BS, Deneen B. The emerging nature of astrocyte diversity. Annu Rev Neurosci. 2019;42:187–207. PubMed

Oberheim NA, Goldman SA, Nedergaard M. Heterogeneity of astrocytic form and function. Methods Mol Biol. 2012;814:23–45. PubMed PMC

Oberheim NA, Takano T, Han X, et al. . Uniquely hominid features of adult human astrocytes. J Neurosci. 2009;29(10):3276–3287. PubMed PMC

Khakh BS, Sofroniew MV. Diversity of astrocyte functions and phenotypes in neural circuits. Nat Neurosci. 2015;18(7):942–952. PubMed PMC

Westergard T, Rothstein JD. Astrocyte diversity: current insights and future directions. Neurochem Res. 2020;45(6):1298–1305. PubMed PMC

Balan S, Toyoshima M, Yoshikawa T. Contribution of induced pluripotent stem cell technologies to the understanding of cellular phenotypes in schizophrenia. Neurobiol Dis. 2019;131:104162. PubMed

Adewumi O, Aflatoonian B, Ahrlund-Richter L, et al. ; International Stem Cell Initiative . Characterization of human embryonic stem cell lines by the International Stem Cell Initiative. Nat Biotechnol. 2007;25(7):803–816. PubMed

Andreasen NC, Flaum M, Arndt S. The Comprehensive Assessment of Symptoms and History (CASH). An instrument for assessing diagnosis and psychopathology. Arch Gen Psychiatry. 1992;49(8):615–623. PubMed

Sheehan DV, Lecrubier Y, Sheehan KH, et al. . The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry. 1998;59(Suppl 20):22–33;quiz 34. PubMed

Grabiec M, Hříbková H, Vařecha M, et al. . Stage-specific roles of FGF2 signaling in human neural development. Stem Cell Res. 2016;17(2):330–341. PubMed

Hříbková H, Grabiec M, Klemová D, Slaninová I, Sun YM. Calcium signaling mediates five types of cell morphological changes to form neural rosettes. J Cell Sci. 2018;131(3):jcs206896. PubMed

Bolger AM, Lohse M, Usadel B. Trimmomatic: a flexible trimmer for Illumina sequence data. Bioinformatics. 2014;30(15):2114–2120. PubMed PMC

Kim D, Langmead B, Salzberg SL. HISAT: a fast spliced aligner with low memory requirements. Nat Methods. 2015;12(4):357–360. PubMed PMC

Liao Y, Smyth GK, Shi W. featureCounts: an efficient general purpose program for assigning sequence reads to genomic features. Bioinformatics. 2014;30(7):923–930. PubMed

Love MI, Huber W, Anders S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 2014;15(12):550. PubMed PMC

Yu G, Wang LG, Han Y, He QY. clusterProfiler: an R package for comparing biological themes among gene clusters. OMICS. 2012;16(5):284–287. PubMed PMC

Piñero J, Ramírez-Anguita JM, Saüch-Pitarch J, et al. . The DisGeNET knowledge platform for disease genomics: 2019 update. Nucleic Acids Res. 2020;48(D1):D845–D855. PubMed PMC

Colombo JA, Reisin HD. Interlaminar astroglia of the cerebral cortex: a marker of the primate brain. Brain Res. 2004;1006(1):126–131. PubMed

Perea G, Navarrete M, Araque A. Tripartite synapses: astrocytes process and control synaptic information. Trends Neurosci. 2009;32(8):421–431. PubMed

Zhang Y, Sloan SA, Clarke LE, et al. . Purification and characterization of progenitor and mature human astrocytes reveals transcriptional and functional differences with mouse. Neuron. 2016;89(1):37–53. PubMed PMC

Schousboe A, Scafidi S, Bak LK, Waagepetersen HS, McKenna MC. Glutamate metabolism in the brain focusing on astrocytes. Adv Neurobiol. 2014;11:13–30. PubMed PMC

Müller N. Inflammation in schizophrenia: pathogenetic aspects and therapeutic considerations. Schizophr Bull. 2018;44(5):973–982. PubMed PMC

Colombo E, Farina C. Astrocytes: key regulators of neuroinflammation. Trends Immunol. 2016;37(9):608–620. PubMed

Akkouh IA, Ueland T, Hansson L, et al. . Decreased IL-1β-induced CCL20 response in human iPSC-astrocytes in schizophrenia: potential attenuating effects on recruitment of regulatory T cells. Brain Behav Immun. 2020;87:634–644. PubMed

Lally J, Gaughran F, Timms P, Curran SR. Treatment-resistant schizophrenia: current insights on the pharmacogenomics of antipsychotics. Pharmgenomics Pers Med. 2016;9:117–129. PubMed PMC

Goldstein ME, Anderson VM, Pillai A, Kydd RR, Russell BR. Glutamatergic neurometabolites in clozapine-responsive and -resistant schizophrenia. Int J Neuropsychopharmacol. 2015;18(6):pyu117. PubMed PMC

Samanaite R, Gillespie A, Sendt KV, McQueen G, MacCabe JH, Egerton A. Biological predictors of clozapine response: a systematic review. Front Psychiatry. 2018;9:327. PubMed PMC

Rizo J, Rosenmund C. Synaptic vesicle fusion. Nat Struct Mol Biol. 2008;15(7):665–674. PubMed PMC

Almonte AG, Sweatt JD. Serine proteases, serine protease inhibitors, and protease-activated receptors: roles in synaptic function and behavior. Brain Res. 2011;1407:107–122. PubMed PMC

Mei YY, Wu DC, Zhou N. Astrocytic regulation of glutamate transmission in schizophrenia. Front Psychiatry. 2018;9:544. PubMed PMC

Kantrowitz JT, Malhotra AK, Cornblatt B, et al. . High dose d-serine in the treatment of schizophrenia. Schizophr Res. 2010;121(1-3):125–130. PubMed PMC

MacKay MB, Kravtsenyuk M, Thomas R, Mitchell ND, Dursun SM, Baker GB. d-serine: potential therapeutic agent and/or biomarker in schizophrenia and depression? Front Psychiatry. 2019;10:25. PubMed PMC

Tanahashi S, Yamamura S, Nakagawa M, Motomura E, Okada M. Clozapine, but not haloperidol, enhances glial d-serine and L-glutamate release in rat frontal cortex and primary cultured astrocytes. Br J Pharmacol. 2012;165(5):1543–1555. PubMed PMC

Clozapine Reverses Dysfunction of Glutamatergic Neurons Derived From Clozapine-Responsive Schizophrenia Patients