Trace elements during primordial plexiform network formation in human cerebral organoids

Abstract

Systematic studies of micronutrients during brain formation are hindered by restrictions to animal models and adult post-mortem tissues. Recently, advances in stem cell biology have enabled recapitulation of the early stages of human telencephalon development. In the present work, we exposed cerebral organoids derived from human pluripotent stem cells to synchrotron radiation in order to measure how biologically valuable micronutrients are incorporated and distributed in the exogenously developing brain. Our findings indicate that elemental inclusion in organoids is consistent with human brain tissue and involves calcium, iron, phosphorus, potassium, sulfur, and zinc. Local trends in concentrations suggest a switch from passive to actively mediated transport across cell membranes. Finally, correlational analysis for pairs of elements shows spatially conserved patterns, suggesting they may physically associate, be stored in similar compartments or used in related biological processes. These findings might reflect which trace elements are important during human brain development and will support studies aimed to unravel the consequences of disrupted metal homeostasis for neurodevelopmental diseases, including those manifested in adulthood.PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2126v1 | CC BY 4.0 Open Access |

Human Cerebral Organoids and Fetal Brain Tissue Share Proteomic Similarities

“…Cerebral organoids have emerged as an unparalleled functional model of the human brain, allowing this organ to be studied mainly during neurodevelopmental stages (Lancaster and Knoblich, 2014; Quadrato and Arlotta, 2017). Previous studies (Lancaster et al, 2013, 2017; Qian et al, 2016; Bershteyn et al, 2017; Birey et al, 2017), including from our group (Sartore et al, 2017), have shown that cerebral organoids are self-organizing and that regionalization follows several neurodevelopmental steps, with a variety of heterogeneous micro-niches being present (Renner et al, 2017). Due to extensive cellular variability, self-patterning, and various tissue architectures, more functional neural networks can be achieved (Quadrato and Arlotta, 2017).…”

“…To resolve the complex proteome of whole, 45-day cerebral organoids, we used state-of-the-art label-free shotgun proteomics to provide broader coverage of cerebral organoids cultured for 45 days (Figure 1A), in which early neuronal network formation already takes place, as previously reported by our group (Sartore et al, 2017). The combined analyses of the organoids identified and quantified 3,073 proteins with at least two unique peptides (Figure 1B, and data on Supplementary Table 1).…”

“…The main efforts to study organoids has been to uncover the typical cellular compositions of neurodevelopmental stages (Lancaster et al, 2013; Camp et al, 2015; Quadrato et al, 2017; Velasco et al, 2019). Using a previously described protocol for whole-cortical organoid (Lancaster et al, 2013; Sartore et al, 2017), cerebral organoids were differentiated for 45 days from human pluripotent stem cells (hPSC) to access their proteome content. At this stage, cerebral organoids present a well-organized structure with ventricle-like cavities, contained cell proliferation zones, and expressed intermediate progenitors followed by early differentiation stage neurons (Sartore et al, 2017).…”

“…The hESC colonies were manually passaged upon 70% confluence and maintained at 37°C in humidified air with 5% CO 2 . The differentiation of PSC into cerebral organoids was performed as previously described (Sartore et al, 2017). Concisely, cells were inoculated in a spinner flask containing mTeSR1 media supplemented with 10 μM Y-27632 (Rho-associated protein kinases inhibitor, iRock) (Merck) under constant rotation (40 rpm).…”

“…Hence, PSC-derived cerebral organoids have recently become a focus in the complex disorders quest. Upon minimal instructions in vitro , cells can self-organize into 3D structures where intrinsic molecular programs are activated to generate diverse neuronal and non-neuronal cell types from CNS specific regions, recapitulating some of the early features of the human brain development (Lancaster et al, 2013; Sasai, 2013; Lancaster and Knoblich, 2014; Quadrato et al, 2017; Sartore et al, 2017). Some recent studies have shown potential for modeling several human disorders using cerebral organoids, such as microcephaly (Lancaster et al, 2013), lissencephaly (Bershteyn et al, 2017), Zika virus infection microcephaly (Cugola et al, 2016; Garcez et al, 2016; Qian et al, 2016), Alzheimer’s disease (Raja et al, 2016), and autism spectrum disorders (Mariani et al, 2015).…”