Human cell-based micro electrode array platform for studying neurotoxicity

Abstract

At present, most of the neurotoxicological analyses are based on in vitro and in vivo models utilizing animal cells or animal models. In addition, the used in vitro models are mostly based on molecular biological end-point analyses. Thus, for neurotoxicological screening, human cell-based analysis platforms in which the functional neuronal networks responses for various neurotoxicants can be also detected real-time are highly needed. Microelectrode array (MEA) is a method which enables the measurement of functional activity of neuronal cell networks in vitro for long periods of time. Here, we utilize MEA to study the neurotoxicity of methyl mercury chloride (MeHgCl, concentrations 0.5–500 nM) to human embryonic stem cell (hESC)-derived neuronal cell networks exhibiting spontaneous electrical activity. The neuronal cell cultures were matured on MEAs into networks expressing spontaneous spike train-like activity before exposing the cells to MeHgCl for 72 h. MEA measurements were performed acutely and 24, 48, and 72 h after the onset of the exposure. Finally, exposed cells were analyzed with traditional molecular biological methods for cell proliferation, cell survival, and gene and protein expression. Our results show that 500 nM MeHgCl decreases the electrical signaling and alters the pharmacologic response of hESC-derived neuronal networks in delayed manner whereas effects can not be detected with qRT-PCR, immunostainings, or proliferation measurements. Thus, we conclude that human cell-based MEA platform is a sensitive online method for neurotoxicological screening.

Is the time right for in vitro neurotoxicity testing using human iPSC-derived neurons?

“…While the costs of human iPSC-derived neurons are still high compared to primary cultures, the availability of human iPSC-derived neurons from particular brain areas and/or patients suffering from a particular neurological disorder opens the iCell neurons for an explorative functional screening, using different physiological, pharmacological and toxicological stimuli. This initial assessment demonstrated that MEA data obtained with iCell neurons are largely in line with previous data from primary cultures (McConnell et al, 2012;Hogberg et al, 2011;Dingemans et al, submitted;Hondebrink et al, 2016) and human embryonic stem cell-derived neurons (Ylä-Outinen et al, 2010). Moreover, iCell neurons challenged with endosulfan or amphetamine (Fig.…”

“…However, as also outlined in NC3R's Neuratect Crack-it Challenge (http://www.NC3Rs.org.uk), the use of human neurons is preferred for in vitro neurotoxicity testing. Still, the use of human neurons for MEA recordings has been limited (Heikkilä et al, 2009;Ylä-Outinen et al, 2010;Kapucu et al, 2012), while there is no indication that human-derived neuronal networks will not exhibit the same properties as primary rat cortical cultures.…”

All Titanium Microelectrode Array for Field Potential Measurements from Neurons and Cardiomyocytes—A Feasibility Study

“…MEAs offer useful, non-invasive, repeatable, and long term setups for neuronal network activity measurements that can be used to study spontaneous activity, effects of electrical and chemical stimuli, and plasticity [6][7][8][9]. Additionally, they can be used for drug screening purposes and for toxicological studies [10,11]. Nevertheless, only a few MEA studies have been conducted with human-derived neurons.…”

Stem Cells and Stem Cell-derived Tissues and Their Use in Safety Assessment

“…The authors demonstrated that molecular targets of botulinum toxin uptake and toxicity are expressed in hPSC-derived neurons; thus, the assay replicates appropriate in vivo toxicity mechanisms. MEA was used to demonstrate subtle perturbations in electrical activity in ESC-derived neurospheres and was more sensitive than measurements of cellular injury and cytotoxicity (48,49). By way of example, hPSC-derived neurons were detectably sensitive to known neurite outgrowth inhibitors such as bisindolylmaleimide I, U0126, lithium, sodium orthovanadate, and brefeldin A; thus, the end point of neurite outgrowth could be an in vitro hallmark of neurotoxicity (45).…”