Carlos Morra: Biomarkers to replae clinicalendpoints for te generation of diagnostic hypotheses with the potental o guide the development of novel psychotherapeutic drugs  

 

Carlos Morra: The use of human-induced pluripotent stem cells (iPSC) in schizophrenia. Will this technology generate a leap forward in the disease´s modeling?*

 

        The development of induced pluripotent stem cells (iPSC) may constitute a significant advance in medical research.

        The differentiation process is a natural mechanism in which embryonic stem cells produce all the body's different mature cells. The belief that this process was a one-way road changed when the Nobel laureate Shinya Yamanaka in 2006 identified four factors, Oct3/4, Sox2, c-Myc and Klf4, from a list of 24 genetic factors he found in the literature associated with pluripotency. When mature cells obtained from living organisms, like fibroblasts or adult peripheral blood, T cells were exposed to them by being infected with their retroviral vectors and regressed into iPSC (Yamanaka 2008).

        There are many significant advantages in using cultures derived from iPSC.

1. They are pluripotent, meaning that they can differentiate in any human cell.

2. They can self-renew, replicating themselves continuously.

3. Finally, they can be generated from the same individuals (Alvarez-Buylla, Seri and Doetsch 2002; Kim and de Vellis 2009; Chen, Lin, Foxe et al. 2013; Avior, Sagi and Benvenisty 2016; Gao, Yourick and Sprando 2017; Szabó, Juhász, Hathy et al. 2020; Larijani, Parhizkar RP, Hadavandkhani et al. 2021). 

This essay will

1. introduce schizophrenia and some current disease models for schizophrenia

2. present some of the findings obtained utilizing iPSC in schizophrenia

3. describe some of the research with iPSCs that might provide newer models for understanding and treating

         

        Schizophrenia is a complex nosological entity empirically derived by Kraepelin (1893), with consideration of the course and outcome, of cross-sectional psychopathology. It affects approximately 1% of the general population. It produces a devastating impact on patients and their families, with a substantial economic burden worldwide (Collins, Patel, Joestl et al. 2011).

        Authors, like Stephan Heckers, questioned the validity of the concept, mainly based on the poorly defined molecular abnormalities and focal pathology - with different onsets, clinical manifestations and outcomes. Its phenotypical heterogeneity occasioned many inconsistencies when adopting models to fully explain its etiology or biological manifestations (Ban 2007; Heckers 2008; Moncrieff and Middleton 2015).

        There are several disease models of schizophrenia that are currently based on findings from other methodologies, such as post-mortem brain studies, morphological and functional brain images, and genetic and tissue cultures.

        The morphologic abnormalities described in schizophrenic brains (Shepherd, Laurens, Matheson et al. 2012) include macroscopic and microscopic manifestations like the reduction of total brain volume, abnormal cell size, reduced spine density and variations of neural distribution in the prefrontal cortex and hippocampus (Harrison 2000; Brennand, Simone, Jou et al. 2011).

        This methodology contributed to the development or validation of many current conceptualizations, such as the dopaminergic, glutamatergic, serotonergic, noradrenergic, cannabinoid, GABAergic, cholinergic and kappa opioid theories (Gierke, Zhao C, Bernstein et al. 2008; Jones, Watson and Fone 2011; Steeds, Carhart-Harris and Stone 2015; Falk, Heine, Harwood et al. 2016; Coyle, Ruzicka and Balu 2020; Christian, Song and Ming 2020; Larijani, Parhizkar RP, Hadavandkhani et al. 2021).

        Most of the existing theories failed to address the disease's dynamic totality and sometimes wrongly assume that concurrent factors are causes or consequences, making it difficult to reach a valid conclusion (Reynolds and Harte 2007; Coyle, Ruzicka and Balu 2020).  

        The recently developed iPSC generation technique introduced a novel approach for identifying and understanding the “etiopathogenic” abnormalities of schizophrenia.

        The possibility of differentiating stem cells in neurons and glial cells, like astrocytes, oligodendrocytes and ependymal cells, can replicate the disease's heterogeneous abnormalities in patient's cells cultures (Brennand, Simone, Jou et al. 2011; Liu, Osipovitch, Benraiss et al. 2019). 

        A paper published by Brennand, Savas, Kim et al. (2015) reported that even neural progenitor cells (NPCs) of schizophrenic patients showed abnormal gene expression and protein levels that may result in changes in migration and responses to oxidative stress.

        Other authors described in cells derived from iPSC several abnormalities such as transcriptome alterations, levels of neuronal differentiation, changes in axonal, dendritic, and synaptic morphology and function, mitochondrial damage, increased expression of mRNA-9, phosphoinositide 3-kinase/glycogen synthase kinase 3 (PI3K/GSK3) signaling alterations, accelerated neural differentiation, GABAergic dysfunctions, changes in WNT signaling, dysregulation of potassium channel-encoding genes in SCZ glial cells, diminished Ca2+ response to glutamatergic signals and altered reactivity to environmental risk factors or challenges (Hashimoto-Torii, Torii, Fujimoto et al. 2014; Liszewska and Jaworski 2018; Ishii, Ishikawa, Fujimori et al. 2019; Wen, Christian, Song and Ming 2016; Hathy, Szabó, Varga et al. 2020; Stertz,  Di Re, Pei et al. 2021).

        These findings assisted in the elaboration of many current disease models. For example, the alterations in WNT signaling initially allegedly responsible for the abnormal neuronal migration patterns in schizophrenia forebrains.

        However, for further consideration, a valid disease model still will be necessary to determine whether these are causal factors leading to altered neural positioning and development or merely the secondary consequences of changes in oxidative stress (Panaccione, Napoletano, Forte et al. 2013; Topol, Zhu, Tran et al. 2015; Hoseth, Krull, Dieset et al. 2018).

        Some other findings described in schizophrenic cell cultures, like the GABAergic interneurons or the glial calcium anomalies, provided new evidence to support other pre-existent theories, like glutamatergic (Boissart, Poulet A, Georges et al. 2013; Hathy, Szabó, Varga et al. 2020; Coyle, Ruzicka and Balu 2020).   

        Neuronal cultures allowed to record high spatial and temporal-resolution in vivo images, obtain sequential real-time information of the disease's pathogeny and maintain all subjects' genetic information and reduce inter-species variability.

        Moreover, manipulating them using invasive techniques, pharmacologic compounds or genome editing techniques provided newer reliable ways to produce and test schizophrenia models and identify future treatment targets (Avior, Sagi and Benvenisty 2016; Quadrato, Brown and Arlotta 2016; Wen, Christian, Song and Ming 2016).

        By recent improvements in the generation process, homogenous cultures of proliferative NPCs were directly generated from mature cells before reaching a pluripotent state (iPSC); this suggested the existence of alternative shortcuts, with a substantial cost and time reduction, but no other significant differences with the cultures derived from iPSC (Szabó, Juhász, Hathy et al. 2020).

        In conclusion, well-defined, enhanced CNS cell cultures derived from iPSC can represent realistic schizophrenia molecular pathophysiology (Larijani, Parhizkar RP, Hadavandkhani et al. 2021).

        The evidence obtained of receptor abnormalities using this technology would allow scientists to identify new treatment targets and propose new disease models focusing on aspects not explained at least entirely, using post-mortem, neuroimaging, animal or genetic studies.

        In the future, developing three-dimensional cultures and organoids might improve studying the disease and reducing, even more, the number of studies employing non-human subjects (Quadrato and Arlotta 2017; Christian, Song and Ming 2020; Larijani, Parhizkar, Hadavandkhani et al. 2021).

        Reaching universal conclusions from the findings of schizophrenics' iPSC cultures has been almost impossible because of the relatively small sample sizes presented in every study; however, using worldwide databases would simplify identifying homogenous phenotypes within the patients.

        Finally, the combination of iPSC with modern gene-editing techniques, like transcription activator-like effector nucleases (TALENs), clustered regularly interspaced short palindromic repeats (CRISPR) provides the ability to reproduce the abnormal findings in genetic “knockout” animals and test the functional consequences of the molecular or genetic abnormalities and validate future models; moreover, finding molecular targets will improve therapeutical applications with all their heuristic implications (Musunuru  2013; Quadrato, Brown and Arlotta 2016; St. Clair and Johnstone 2018).

 

References:

Alvarez-Buylla A, Seri B, Doetsch F. Identification of neural stem cells in the adult vertebrate brain. Brain Rese Bull 2002;57(6):751-8.

Avior Y, Sagi I, Benvenisty N. Pluripotent stem cells in disease modelling and drug discovery. Nat Rev Mol Cell Biol 2016;17(3):170-82.

Boissart C, Poulet A, Georges P, Darville H, Julita E, Delorme R, Bourgeron T, Peschanski M,  Benchoua A. Differentiation from human pluripotent stem cells of cortical neurons of the superficial layers amenable to psychiatric disease modeling and high-throughput drug screening. Transl Psychiatry 2013;3(8):e294.

Brennand K, Savas JN, Kim Y, Tran N, Simone A, Hashimoto-Torii K, Beaumont KG, Kim HJ, Topol A, Ladran I, Abdelrahim M, Matikainen-Ankney B, Chao SH, Mrksich M, Rakic P, Fang G, Zhang B, Yates JR 3rd, Gage FH. Phenotypic differences in hiPSC NPCs derived from patients with schizophrenia. Mol Psychiatry 2015;20(3):361-8.

Brennand KJ, Simone A, Jou J, Gelboin-Burkhart C, Tran N, Sangar S, Li Y, Mu Y, Chen G, Yu D, McCarthy S, Sebat J, Gage FH. Modelling schizophrenia using human induced pluripotent stem cells. Nature 2011;473(7346):221-5.

Chen J, Lin M, Foxe J, Pedrosa E, Hrabovsky A, Carroll R, Zheng D, Lachman HM. Transcriptome comparison of human neurons generated using induced pluripotent stem cells derived from dental pulp and skin fibroblasts. PloS One 2013;8(10):E75682.

Christian KM, Song H, Ming GL. Using Two- and Three-Dimensional Human iPSC Culture Systems to Model Psychiatric Disorders. Adv Neurobiol 2020;25:237-57.

Collins PY, Patel V, Joestl SS, March D, Insel TR, Daar AS, Scientific Advisory Board and the Executive Committee of the Grand Challenges on Global Mental Health, Anderson W, Dhansay MA, Phillips A, Shurin S, Walport M, Ewart, Savill J, Bordin IA, Costello EJ, Durkin M, Fairburn C, Glass RI, Hall W, Huang Y, Hyman SE, Jamison K, Kaaya S, Kapur S, Kleinman A, Ogunniyi A, Otero-Ojeda A, Poo M-M, Ravindranath V, Sahakian BJ, Saxena S, Singer PA, Stein DJ. Grand challenges in global mental health. Nature 2011;475(7354):27-30.

Coyle JT, Ruzicka WB, Balu DT. Fifty Years of Research on Schizophrenia: The Ascendance of the Glutamatergic Synapse. Am J Psychiatry 2020;177(12):1119-28.

Falk A, Heine VM, Harwood AJ, Sullivan PF, Peitz M, Brüstle O, Shen S, Sun YM, Glover JC, Posthuma D, Djurovic S. Modeling psychiatric disorders: from genomic findings to cellular phenotypes. Mol Psychiatry 2016;21(9):1321.

Gao X, Yourick JJ, Sprando RL. Comparative transcriptomic analysis of endothelial progenitor cells derived from umbilical cord blood and adult peripheral blood: Implications for the generation of induced pluripotent stem cells. Stem Cell Res 2017;25:202-12.

Gierke P, Zhao C, Bernstein H-G, Noack C, Anand R, Heinemann U, Braunewell K-H. Implication of neuronal Ca2+-sensor protein VILIP-1 in the glutamate hypothesis of schizophrenia. Neurobiol Dis 2008;32(1):162-75.

Harrison PJ. Postmortem studies in schizophrenia. Dialogues Clin Neurosci 2000;2(4):349-57.

Hashimoto-Torii K, Torii M, Fujimoto M, Nakai A, El Fatimy R, Mezger V, Ju MJ, Ishii S, Chao SH, Brennand KJ, Gage FH, Rakic P. Roles of heat shock factor 1 in neuronal response to fetal environmental risks and its relevance to brain disorders. Neuron 2014;82(3):560-72.

Hathy E, Szabó E, Varga N, Erdei Z, Tordai C, Czehlár B, Baradits M, Jezsó B, Koller J, Nagy L, Molnár MJ, Homolya L, Nemoda Z, Apáti Á, Réthelyi JM. Investigation of de novo mutations in a schizophrenia case-parent trio by induced pluripotent stem cell-based in vitro disease modeling: convergence of schizophrenia- and autism-related cellular phenotypes. Stem Cell Res Ther 2020;11(1):504.

Heckers S. Making progress in schizophrenia research. Schizophr Bull 2008;34(4):591-4.

Hoseth EZ, Krull F, Dieset I, Mørch RH, Hope S, Gardsjord ES, Steen NE, Melle I, Brattbakk HR, Steen VM, Aukrust P, Djurovic S, Andreassen OA, Ueland T. Exploring the Wnt signaling pathway in schizophrenia and bipolar disorder. Transl Psychiatry 2018;8(1):55.

Ishii T, Ishikawa M, Fujimori K, Maeda T, Kushima I, Arioka Y, Mori D, Nakatake Y, Yamagata B, Nio S, Kato TA, Yang N, Wernig M, Kanba S, Mimura M, Ozaki N, Okano H. In Vitro Modeling of the Bipolar Disorder and Schizophrenia Using Patient-Derived Induced Pluripotent Stem Cells with Copy Number Variations of PCDH15 and RELN. eNeuro 2019;6(5):ENEURO.0403-18.2019

Jones CA, Watson DJ, Fone KC. Animal models of schizophrenia. Br J Pharmacol 2011;164(4):1162-94.

Kim SU, de Vellis J. Stem cell-based cell therapy in neurological diseases: a review. Neurosci Res 2009;87(10):2183-200.

Kraepelin E. Lehrbuch der Psychiatrie. 4 Aufl. Barth; 1893.

Larijani B, Parhizkar RP, Hadavandkhani M, Alavi-Moghadam S, Rezaei-Tavirani M, Goodarzi P, Sayahpour FA, Mohamadi-Jahani F, Arjmand B. Stem cell-based models and therapies: a key approach into schizophrenia treatment. Cell Tissue Bank 2021;22(2):207-23.

Liszewska E, Jaworski J. Neural Stem Cell Dysfunction in Human Brain Disorders. In: Buzanska L, editor. Human Neural Stem Cells: From Generation to Differentiation and Application. Springer International Publishing; 2018, pp. 283–305.

Liu Z, Osipovitch M, Benraiss A, Huynh N, Foti R, Bates J, Chandler-Militello D, Findling RL, Tesar PJ, Nedergaard M, Windrem MS, Goldman SA. Dysregulated Glial Differentiation in Schizophrenia May Be Relieved by Suppression of SMAD4- and REST-Dependent Signaling. Cell Rep 2019;27(13):3832-43.e6.

Moncrieff J, Middleton H. Schizophrenia: a critical psychiatry perspective. Curr Opin Psychiatry 2015 May;28(3):264-8.

Musunuru K. Genome editing of human pluripotent stem cells to generate human cellular disease models. Dis Model Mech 2013;6(4):896-904 .

Panaccione I, Napoletano F, Forte AM, Kotzalidis GD, Del Casale A, Rapinesi C, Brugnoli C, Serata D, Caccia F, Cuomo I, Ambrosi E, Simonetti A, Savoja V, De Chiara L, Danese E, Manfredi G, Janiri D, Motolese M, Nicoletti F, Girardi P, Sani, G. Neurodevelopment in schizophrenia: the role of the wnt pathways. Curr Neuropharmacol 2013;11(5):535-8.

Quadrato G, Arlotta P. Present and future of modeling human brain development in 3D organoids. Curr Opin Cell Biol 2017;49:47-52.

Quadrato G, Brown J, Arlotta, P. The promises and challenges of human brain organoids as models of neuropsychiatric disease. Nat Med 2016;22(11):1220-28.

Reynolds GP, Harte MK. The neuronal pathology of schizophrenia: molecules and mechanisms. Biochem Soc Trans 2007;35(Pt 2):433-6. 

Shepherd AM, Laurens KR, Matheson SL, Carr VJ, Green MJ. Systematic meta-review and quality assessment of the structural brain alterations in schizophrenia. Neurosci Biobehav Rev 2012;36(4):1342-56.

St. Clair D, Johnstone M. Using mouse transgenic and human stem cell technologies to model genetic mutations associated with schizophrenia and autism. Philos Trans R Soc Lond B Biol Sci 2018;373(1742):20170037.

Steeds H, Carhart-Harris RL, Stone JM. Drug models of schizophrenia. Ther Adv Psychopharmacol 2015;5(1):43-58.

Stertz L, Di Re J, Pei G, Fries GR, Mendez E, Li S, Smith-Callahan L, Raventos H, Tipo J, Cherukuru R, Zhao Z, Liu Y, Jia P, Laezza F, Walss-Bass C. Convergent genomic and pharmacological evidence of PI3K/GSK3 signaling alterations in neurons from schizophrenia patients. Neuropsychopharmacology 2021;46(3):673-82.

Szabó E, Juhász F, Hathy E, Reé D, Homolya L, Erdei Z, Réthelyi JM, Apáti Á. Functional Comparison of Blood-Derived Human Neural Progenitor Cells. Int J Mol Sci 2020;21(23):9118.

Topol A, Zhu S, Tran N, Simone A, Fang G, Brennand KJ. Altered WNT Signaling in Human Induced Pluripotent Stem Cell Neural Progenitor Cells Derived from Four Schizophrenia Patients. Biol Psychiatry 2015;78(6):e29-34.

Wen Z, Christian KM, Song H, Ming GL. Modeling psychiatric disorders with patient-derived iPSCs. Curr Opin Neurobiol 2016;36:118-27.

Yamanaka S. Induction of pluripotent stem cells from mouse fibroblasts by four transcription factors. Cell proliferation 2008; 41(Suppl 1):51-6.

*This essay is based on an assignment Carlos Morra completed for a Master’s course in Science in Applied in Neuroscience at King´s College London and submitted in February 2021.

  

June 24, 2021