2D-Gel Electrophoresis Analysis of Proteomic Changes in Three Human Cell Lines; HEK 293, HepG2 and 1321N1 Cells in Response to Cadmium

Title:2D-Gel Electrophoresis Analysis of Proteomic Changes in Three Human Cell Lines; HEK 293, HepG2 and 1321N1 Cells in Response to Cadmium

Volume: 11 Issue: 1

Author(s): Akeem O. Lawal and Elizabeth M. Ellis

Affiliation:

Keywords: Albumin, ATP synthase, cadmium toxicity, calreticulin, C-protein, 2D-electrophoresis.

Abstract: Cadmium (Cd) is a well known environmental and industrial heavy metal with multi-organ toxic effects. In this study, we examined the effects of Cd as cadmium chloride (CdCl₂) on the proteomic profiles of exposed HEK 293, HepG2 and 1321N1 cells in an attempt to develop suitable biomarkers for Cd toxicity. 2D-gel electrophoresis (2DE) was performed on the cell extracts after 24 hr exposure to 5, 10 and 50 µM Cd and protein spots were compared using Phoretix ^TM 2D analysis software. Comparisons were made between Cd treated and untreated cells and spots were identified by mass spectroscopy using peptide-mass fingerprinting and database searching. The results show that the different concentrations (5-50 µM) of CdCl₂ used in this study caused at least 1-5-fold induction in some proteins in the three cell lines. A common feature in the proteomic profile was identified in HepG2 and HEK 293 cells after exposure to 5 µM CdCl₂ and this was the induction of one of the subunits of ATP synthase. 2DE analysis shows a 2.95- and 2.54-fold induction in ATP synthase in HEK 293 and HepG2 cells, respectively after 24 hr exposure to 5 µM CdCl₂. However, western blot validation shows 4.8- and 3.54-fold induction in ATPase in HEK 293 and HepG2 cells respectively. Both 2DE and western blot analysis shows a 2.2-fold induction in calreticulin, a Ca²⁺-binding protein, in HepG2 cells after 24 hr exposure to 5 µM CdCl₂.Though 2DE analysis shows a 1.7-fold induction in Albumin (ALB) protein in HEK 293 cells exposed to 50 µM CdCl₂, western blot analysis, however, shows a 10-fold increase. Exposure to 5 µM Cd also induced (1.8-fold) C-protein expression in 1321N1 cells. However, western blot analysis shows a 4.5-fold increase. These results suggest that Cd drastically alters the proteomic profiles of exposed cells, which include alterations in the expressions of proteins, involve in metabolism and intracellular Ca²⁺ homeostasis. These alterations may be important hallmarks in identifying Cd toxicity.

Cite this article as:

Lawal O. Akeem and Ellis M. Elizabeth, 2D-Gel Electrophoresis Analysis of Proteomic Changes in Three Human Cell Lines; HEK 293, HepG2 and 1321N1 Cells in Response to Cadmium, Current Proteomics 2014; 11 (1) . https://dx.doi.org/10.2174/1570164611666140218232521