Comprehensive Evaluation of microRNA Expression Profiling Reveals the Neural Signaling Specific Cytotoxicity of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) through N-Methyl-D-Aspartate Receptor

March Comprehensive Evaluation of microRNA Expression Profiling Reveals the Neural Signaling Specific Cytotoxicity of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) through N-Methyl-D-Aspartate Receptor Bo Sun 0 1 2 Rui Liu 0 1 2 Nan Ye 0 1 2 Zhong-Dang Xiao 0 1 2 0 1 State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096 , P. R. China , 2 Institute of Microbiology, School of Biological Sciences, Seoul National University , Seoul , South Korea , 3 Laboratory of Biophysics, School of Biological Sciences, Seoul National University , Seoul , South Korea 1 Data Availability Statement: All relevant data are within the paper 2 Academic Editor: Bing Xu, Brandeis University , UNITED STATES Though nanomaterials are considered as drug carriers or imaging reagents targeting the central nervous system their cytotoxicity effect on neuronal cells has not been well studied. In this study, we treated PC12 cells, a model neuronal cell line, with a nanomaterial that is widely accepted for medical use, superparamagnetic iron oxide nanoparticles (SPIONs). Our results suggest that, after treated with SPIONs, the expression pattern of the cellular miRNAs changed widely in PC12 cells. As potential miRNA targets, NMDAR, one of the candidate mRNAs that were selected using GO and KEGG pathway enrichment, was significantly down regulated by SPIONs treatment. We further illustrated that SPIONs may induce cell death through NMDAR suppression. This study revealed a NMDAR neurotoxic effect of SPIONs and provides a reliable approach for assessing the neurocytotoxic effects of nanomaterials based on the comprehensive annotation of miRNA profiling. - The rapid development of nanotechnology provides a flexible platform for generating nanomaterials with specific functions for medical applications due to their unique properties. For example, nanoparticles, which usually are 10100 nm in diameter, can easily flow through blood capillaries to reach their target sites. Nanoparticles can be technologically engineered and modified so that they carry components for medical imaging, cancer therapy or drug release [19]. Because of the versatile nature of the conjugate, nanomaterial has been wildly used in diagnosis and treatment. Different bulk forms can be generated by different nanotechnology procedures Competing Interests: The authors have declared that no competing interests exist. and may endow a given nanomaterial with new properties, in some cases involving completely unexpected physical and chemical properties [1013]. For this reason, the de novo capabilities of nanomaterials are still under investigation. Besides the emerging applications of nanomaterials in biological systems, the cellular effects of nanomaterials are still unclear. Several studies based on the toxicity of nanomaterial in biological systems indicate the need for a new scientific discipline focused on nanotoxicity [1418]. Due to the complexity of nanomaterials and their effects on living organisms, few studies have been able to make a robust conclusion about the cytotoxicity of certain nanomaterials. Indeed, for some nanomaterials that are suggested to have low cytotoxicity, their cellular effect and long-term safety need further inspection. Unfortunately, except for the conventional toxicity assay, there is a lack of reliable methodology for systematically assessing the overall cellular effects of specific materials. The overwhelming majority of assays to test nanotoxicity in biological systems are performed in vitro with the advantages over in vivo studies of providing less ethical ambiguity, being easier to reproduce and carrying less expense. Conventional tests for cellular nanotoxicity include assays for cytotoxicity, genotoxicity or altered gene expression, and these assessments are carried out using standard in vitro assays, such as Northern blotting, real-time PCR, or microarray analyses [1921]. Based on high-throughput microarray and bioinformatics analyses, gene expression profiling may provide a systematic method for examining the biocompatibility of nanomaterials. However, mRNA assays may not accurately reflect the response state of a cell due to the inescapable degradation of a portion of the mRNAs during sample preparation and the regulation of proteins through post-transcriptional mechanisms such as effects on translation. MicroRNAs (miRNAs) are short RNA molecules working as post-transcriptional regulators by binding to complementary sequences on target mRNA transcripts. By enacting gene silencing through translational repression or target degradation, miRNAs may regulate comprehensive biological processes, including cell viability, proliferation, development and differentiation [2226]. Methods have been developed for profiling miRNA expression, for example, the deep sequencing technique [27]. Based on the increased stability of miRNA during sample processing, miRNA expres (...truncated)