Effect of long-term exposure of SH-SY5Y cells to morphine: a whole cell proteomic analysis

Abstract

Background: Opiate addiction reflects plastic changes that endurably alter synaptic transmission within relevant neuronal circuits. The biochemical mechanisms of these adaptations remain largely unknown and proteomics-based approaches could lead to a broad characterization of the molecular events underlying adaptations to chronic drug exposure.

Results: Thus, we have started proteomic analyses of the effects of chronic morphine exposure in a recombinant human neuroblastoma SH-SY5Y clone that stably overexpresses the mu-opioid receptor. Cells were treated with morphine for 6, 24 and 72 hours, the proteins were separated by 2-D gel electrophoresis and stained with Coomassie blue, and the protein map was compared with that obtained from untreated cells. Spots showing a statistically significant variation were selected for identification using mass spectrometric analyses.

Conclusion: A total of 45 proteins were identified, including proteins involved in cellular metabolism, cytoskeleton organization, vesicular trafficking, transcriptional and translational regulation, and cell signaling.

Figure 1

2-DE pattern of untreated (A) and 6 h morphine-treated (B) SH-SY5Y cells. Sample were resolved by 2-DE on non-linear pH 3–10 IPG strips followed by separation on a 12% SDS-PAGE gel in the second dimension. Proteins were visualized by colloidal coomassie staining. The box in 1B delineates the close-up presented on figure 2.

Figure 2

Close-up from a representative 2-D gel showing the spots whose abundance in SH-SY5Y cells is regulated after chronic morphine treatment. Spots numbers refer to numbers on Tables 1, 2 and 3 where quantitative analysis and mass spectrometric data are presented.