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 vitro. In the present work, we analyzed cerebral organoids derived from human pluripotent stem cells by synchrotron radiation X-ray fluorescence in order to measure biologically valuable micronutrients incorporated and distributed into the exogenously developing brain. Our findings indicate that elemental inclusion in organoids is consistent with human brain tissue and involves P, S, K, Ca, Fe and Zn. Occurrence of different concentration gradients also suggests active regulation of elemental transmembrane transport. Finally, the analysis of pairs of elements shows interesting elemental interaction patterns that change from 30 to 45 days of development, suggesting short- or long-term associations, such as storage in similar compartments or relevance for time-dependent biological processes. These findings shed light on 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.

Computational fluid dynamic analysis of physical forces playing a role in brain organoid cultures in two different multiplex platforms

“…On day 6, EBs were transferred to 24-well ultralow-attachment culture plates (one/well) containing 0.5 ml neuroinduction medium [1% N 2 supplement (Gibco), 1% GlutaMAX (Life Technologies), 1% MEM-NEAAs, 1% P/S, and 1 μg/ml heparin in DMEM/F12 (Life Technologies). After 4 days (day 10), organoids were coated with Matrigel similarly as described by Sartore et al (2017) [21] in a 60-mm non-adherent tissue culture plate; six organoids were placed in 3 ml diluted Matrigel and incubated for 1 h at 37 °C under 5% CO 2 . The coated organoids were then returned to the 24-well ultra-low-attachment plates with 0.5 ml neurodifferentiation medium with no vitamin A (50% neurobasal medium, 0.5% N 2 , 1% B 27 supplement without vitamin A, 1:100 2-mercapto-ethanol, 0.5% MEM-NEAA, 1% GlutaMAX, and 1:100 P/S in DMEM/F12) and left for 4 days in static culture.…”

Recent Trends and Perspectives in Cerebral Organoids Imaging and Analysis

“…In order to quantify the proportion of cell components or molecules inside brain cultures, marker intensity measure has been proposed (around 7% of the image analysis). Different markers can then be measured: neurotransmitters (Sartore et al, 2017;Jorfi et al, 2018), molecule transporters (Wilpert et al, 2020), infiltration of tumors (Liu et al, 2020), nuclei (Rakotoson et al, 2019), or pathological markers (Lin et al, 2018b).…”

“…They are part of tools to measure the size of cerebral organoid to evaluate their growth or to compare different groups of culture (healthy and disease models, for example). Indeed, their size is evaluated by their diameter (Monzel et al, 2017;Sartore et al, 2017;Sivitilli et al, 2020) or perimeter (Buchsbaum et al, 2020) on bright-field images. Others authors use confocal microscopy to measure the size in term of perimeter (Iefremova et al, 2017).…”

Innovations in 3D Tissue Models of Human Brain Physiology and Diseases

“…Brain organoids are also useful tools for examining brain function and related pathology that does not depend on a genetic component per se. Organoids have been used to model changes in neurodevelopment caused by hypoxia (and rescue thereof) [155,156] and exposure to trace elements, [157] anticancer agents, [158] substances of abuse, [159][160][161] therapeutic drugs, [162] and natural products that purportedly improve brain function. [163] Brain organoids have similarly proven to be a useful tool in elucidating the pathology underlying prion [164] and viral infection, such as Herpes Simplex, [165] Dengue, [166] and, in particular, Zika virus (see below).…”