Establishing a novel in vitro-model for inflammation induced depression based on human iPSC-derived co-culture of serotonergic neurons, microglia, and mast cells
Molecular and Cellular Neurology and Neuropathology
Final Report Abstract
Understanding the cellular and molecular mechanisms behind neuropsychological disorders like major depressive disorder (MDD) is crucial yet remains incomplete. This study focused on developing a human-derived in vitro-model using induced pluripotent stem cells (iPSCs) to investigate the impact of neuroinflammation on the serotonergic system, a key player in depression. The differentiation protocols were established for two healthy control iPSC lines. Neuronal progenitor cells were directed into the serotonergic lineage by optimizing growth factor and small molecule regimens. After maturation, serotonergic neurons showed spontaneous as well as stimulated serotonin release and uptake. Differentiated microglia showed a typical inflammatory response to lipopolysaccharide (LPS) by transcriptional and morphological adaptations, while mast cell functionality is currently being refined with advanced stimulation techniques. The impact of inflammation was explored after acute and chronic treatment of serotonergic neurons with the proinflammatory stimuli histamine. Histamine exposure reduced serotonin release, altered the efficacy of antidepressants, such as sertraline and escitalopram, and induced morphological changes in serotonergic neurons. In neuron-microglia co-cultures overall reduced serotonin release was observed, with inflammatory activation aggravating this effect. Further transcriptomic analyses and integration of optogenetic stimulation are planned to refine the model and understand underlying mechanisms. To advance the throughput and accessibility of electrochemical measurement techniques, such as fast-scan cyclic voltammetry (FSCV), a microfluidic platform with integrated carbon electrodes was designed. The platform will allow the measurement of ambient levels of serotonin in parallel to real-time measurements of dynamic changes of serotonin. Laser-induced pyrolysis was established as a reproducible fabrication technique to produce novel, customizable carbon electrodes that effectively detected serotonin and can be integrated into the platform. In sum, differentiation protocols for serotonergic neurons, immune cells and co-cultures were successfully developed and functional, real-time measurements were made from these cultures. The project highlights how neuroinflammatory processes disrupt serotonergic signalling and will provide a robust electrochemical measurement platform for future translational investigations into depression and therapeutic interventions.
Link to the final report
https://doi.org/10.25560/119049
Publications
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Flash presentation & poster, BioMedEng, London, Jul 2024: Novel approaches how to study Serotonin dynamics using Fast-Scan Cyclic Voltammetry
Bohl, Bettina
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Invited talk, International Transmembrane Transporter Society meeting, Bethesda, Oct 2024: Adapting FSCV to Analyze Neurotransmitter Dynamics in Advanced Human-derived 3D Cell Culture Models to Bridge the Gap Between Lab and Clinic
Bohl, Bettina
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Mapping the druggable targets displayed by human colonic enteroendocrine cells. openRxiv.
Lei, Yuxian; Bohl, Bettina; Meyer, Leah; Jacobs, Margot; Haq, Naila; Yang, Xiaoping; Hayee, Bu’ Hussain; Murphy, Kevin G.; Hashemi, Parastoo & Bewick, Gavin A.
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Measurement of Real Time Serotonin Dynamics from Human Derived Gut Organoids. openRxiv.
Bohl, Bettina; Lei, Yuxian; Bewick, Gavin A. & Hashemi, Parastoo
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Poster presentation, ISSCR, Hamburg, Jul 2024: using electrochemistry to study neurotransmitter release from human stem cell-derived 3d model systems in real-time
Bohl, Bettina
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Poster presentation, Monitoring Molecules in Neuroscience Society Meeting, Chapel Hill, May 2024: Monitoring neurotransmitter release from human-derived 3D organoids and spheroids by FSCV
Bohl, Bettina
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Talk, Pittcon, San Diego, Feb 2024: Human Cell Culture Model for Fast-Scan Cyclic Voltammetry Measurements to Study Depression and Neuroinflammation
Bohl, Bettina
