Anti-Neuronal Marker Monoclonal antibody, clone zn-8

Stem cell-derived specialized cell types are of interest as an alternative cell system to identify and research neurotoxic effects and modes of action. Developmental toxicity may be studied during differentiation, while organ-specific toxicity may be assessed in fully functional cells, such as neurons. In this study we tested if fully differentiated neurons derived from murine embryonic stem cells (ESCN) could be used to investigate the effects of the well characterized neurotoxic model compound acrylamide (ACR) and if ESCN behave similar to murine primary cortical neurons (pCN) from 16 days old embryos. We characterized the differentiation process of cryopreserved ESC-derived neural precursor cells (NPC) differentiating to ESCN. During the differentiation process (days 11-20) a strong increase in calcium responses to glutamate, acetylcholine and GABA were observed. Moreover, neuron specific marker proteins, beta-III-tubulin, MAP2, Tau, Rbfox3 and synaptophysin showed similar patterns to pCN. In ESCN and pCN the neuronal structure, e.g. neurites, was not affected bylaw concentrations of ACR [0.5-1.6 mM]. However, 24 h incubation periods with 0.5-1.6 mM ACR led to a reduction of acetylcholine and glutamate induced calcium responses. In conclusion, we show that non-cytotoxic concentrations of ACR alter neurotransmission in ESCN as well as pCN. (C) 2014 Elsevier Inc. All rights reserved.

Alternative premRNA splicing is a major mechanism to generate diversity of gene products. However, the biological roles of alternative splicing during development remain elusive. Here, we focus on a neuron-specific RNA-binding protein, Rbfox3, recently identified as the antigen of the widely used anti-NeuN antibody. siRNA-mediated loss-of-function studies using the developing chicken spinal cord revealed that Rbfox3 is required to promote neuronal differentiation of postmitotic neurons. Numb premRNA encoding a signaling adaptor protein was found to be a target of Rbfox3 action, and Rbfox3 repressed the inclusion of an alternative exon via binding to the conserved UGCAUG element in the upstream intron. Depleting a specific Numb splice isoform reproduced similar neuronal differentiation defects. Forced expression of the relevant Numb splice isoform was sufficient to rescue, in an isoform-specific manner, postmitotic neurons from defects in differentiation caused by Rbfox3 depletion. Thus, Rbfox3-dependent Numb alternative splicing plays an important role in the progression of neuronal differentiation during vertebrate development.