Differentiating neurons derived from human umbilical cord blood stem cells work as a test system for developmental neurotoxicity

Abstract

Differentiating neuronal cells derived from human umbilical cord blood stem cells have been used as an in vitro tool for the assessment of developmental neurotoxicity of monocrotophos (MCP), an organophosphate pesticide. The differentiating cells were exposed to MCP during the different stages of maturation, viz., days 2, 4, and 8, and changes in the makers of cell proliferation, neuronal differentiation, neuronal injuries, and receptors were studied. We found significant upregulation in the different MAPKs, apoptosis, and neurogenesis markers and downregulation in the cell proliferation markers during neuronal differentiation. We further identified significant upregulation in the expression of different MAPKs and proteins involved in oxidative stress, apoptosis, and calpain pathways in the mid-differentiating cells exposed to MCP. The upregulated levels of these proteins seem to be the main cause of alteration during the differentiation process towards apoptosis as a fine-tune of pro-apoptotic and anti-apoptotic proteins are desirable for the process of differentiation without apoptosis. The decreased acetylcholinesterase activity, dopaminergic, and cholinergic receptors and increased acetylcholine levels in the differentiating neuronal cells indicate the vulnerability of these cells towards MCP-induced neurotoxicity. Our data confirms that differentiating neuronal cells derived from human umbilical cord stem cells could be used as a powerful tool to assess the developmental neurotoxicity in human beings.

An Overview on Human Umbilical Cord Blood Stem Cell-Based Alternative In Vitro Models for Developmental Neurotoxicity Assessment

“…hUCBSCs express pluripotency markers such as Oct-3/4, Sox-2, Nanog and cMyc which are usually expressed in pluripotent embryonic stem cells and thought to play key roles in maintaining pluripotency and self-renewal capabilities [49,[69][70][71]. Similarly, we also found high expression of these pluripotency markers namely, Oct-3/4, Sox-2, Nanog and c-Myc in CD34 + /Thy1 + hUCB-HSCs, and moreover, the expression levels of these pluripotency markers were reduced during the differentiation of these hUCBSCs into neuronal cells [34][35][36]. These purified and characterized populations of hUCBSCs have great plasticity potential towards various specialized cell types of all three germ layers [72].…”

“…These limitations are major hurdles to use human embryonic or neural stem cells for creating novel alternative in vitro model for DNT studies. Alternatively, hUCBSCs could serve the purpose and have been proved to be the most promising in vitro tools for DNT studies [33][34][35][36]47]. There is no concern about teratoma formation in the neuronal cells derived from hUBSCs and also have almost no ethical concern.…”

“…Pluripotent stem cells derived from human umbilical cord blood have similar potential of neuronal differentiation as neural stem cells derived from foetus [34][35][36][93][94][95][96][97][98][99]. Neurons derived from these hUCBSCs have expression of different early and mature neuronal markers namely, nestin, musashi-1, nectin, neuronal nuclei (NeuN), post-synaptic density protein 95 (PSD95), synaptophysin (SYP), β-III tubulin (TUJ-1), growth-associated protein 43 (GAP43), various forms of neurofilaments (NF), neurotrophic growth factors and neuron-specific receptors N-methyl-D-aspartate (NMDA) and γ-aminobutyric acid (GABA) [34-36, 38, 53, 86, 94, 100-107].…”

“…Therefore, stem cells from different sources are particularly suited to study DNTs [32][33][34][35][36]. In the last few decades, establishment of stem cell-based in vitro model systems for DNT assessment has been the subject of high thrust in all over the world.…”

Progress toward the development of in vitro model system for chemical-induced developmental neurotoxicity: potential applicability of stem cells

“…B. Pant (*) In Vitro Toxicology Laboratory, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India e-mail: abpant@rediffmail.com; abpant@yahoo.com acetylcholinesterase activity was reduced and acetylcholine levels were upregulated. MCP exposure was also capable of reducing the receptor binding specificity in case of cholinergic and dopaminergic receptors (Kashyap et al 2014).…”