Evaluation of Graphene Oxide Induced Cellular Toxicity and Transcriptome Analysis in Human Embryonic Kidney Cells

Abstract

Graphene, a two-dimensional carbon sheet with single-atom thickness, shows immense promise in several nanoscientific and nanotechnological applications, including in sensors, catalysis, and biomedicine. Although several studies have shown the cytotoxicity of graphene oxide in different cell types, there are no comprehensive studies on human embryonic kidney (HEK293) cells that include transcriptomic analysis and an in vitro investigation into the mechanisms of cytotoxicity following exposure to graphene oxide. Therefore, we exposed HEK293 cells to different concentrations of graphene oxide for 24 h and performed several cellular assays. Cell viability and proliferation assays revealed a significant dose-dependent cytotoxic effect on HEK293 cells. Cytotoxicity assays showed increased lactate dehydrogenase (LDH) leakage and reactive oxygen species (ROS) generation, and decreased levels of reduced glutathione (GSH) and increased level of oxidized glutathione indicative of oxidative stress. This detailed mechanistic approach showed that graphene oxide exposure elicits significant decreases in mitochondrial membrane potential and ATP synthesis, as well as in DNA damage and caspase 3 activity. Furthermore, our RNA-Seq analysis revealed that HEK293 cells exposed to graphene oxide significantly altered the expression of genes involved in multiple apoptosis-related biological pathways. Moreover, graphene oxide exposure perturbed the expression of key transcription factors, promoting these apoptosis-related pathways by regulating their downstream genes. Our analysis provides mechanistic insights into how exposure to graphene oxide induces changes in cellular responses and massive cell death in HEK293 cells. To our knowledge, this is the first study describing a combination of cellular responses and transcriptome in HEK293 cells exposed to graphene oxide nanoparticles, providing a foundation for understanding the molecular mechanisms of graphene oxide-induced cytotoxicity and for the development of new therapeutic strategies.

<p>Graphene Oxide Negatively Regulates Cell Cycle in Embryonic Fibroblast Cells</p>

“…40 RNA-sequencing data analysis by Gurunathan et al revealed that GO, through changingexpression of genes involved in apoptosis-related biological pathways in HEK293 cells, triggered apoptosis and cell death, in agreement with our results. 42 Tang et al showed that exposing K7M2 cells to GO increased cell apoptosis due to generation of ROS, confirmed our apoptosis-and ROS-assay results, as more ROS generation led to higher levels of apoptosis. 43 Cell cycle-analysis also showed a block in the G 2 /M phase in GO-treated groups, but the pattern for 200 µg/mL nGO was completely different, as this treatment increased the G 2 /M phase more than the control group.…”

Cytotoxicity and Immune Dysfunction of Dendritic Cells Caused by Graphene Oxide

“…In this work, we aimed to determine the effects of mono-GO and multi-GO on DCs using in vitro cell model. According to bioapplication and various toxicity studies of GO (Shao et al, 2017;Hoyle et al, 2018;Pelin et al, 2018;Gurunathan et al, 2019a), we finally selected concentrations of 0.01 mg/ml, 0.1 mg/ml, 1 mg/ml, 10 mg/ml, and 100 mg/ml for in vitro toxicity tests. Here, our results showed mono-GO is less toxic to DCs than multi-GO.…”

Antiviral Potential of Nanoparticles—Can Nanoparticles Fight Against Coronaviruses?

“…GO and its derivatives are of immense interest to nanomedicine researchers due to their remarkable electronic, mechanical and thermal properties [113]. GO is widely used as an antibacterial and anticancer agent [114]. GO act as antiviral agent through inactivation of the pathogenic agent of hand-foot-and-mouth disease, EV71 and endemic gastrointestinal avian influenza A virus H9N2 [115].…”