Related Experiment Videos
An integrated approach to proteome analysis: identification of proteins associated with cardiac hypertrophy
D Arnott1, K L O'Connell, K L King
1Protein Chemistry Department, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA.
Insights
Cardiac hypertrophy, a predictor of heart failure, was studied using proteomic analysis. Researchers identified key proteins altered in hypertrophied cardiac cells, advancing heart disease research.
Area of Science:
- Cardiovascular Biology
- Proteomics
- Molecular Biology
Background:
- Cardiac myocyte hypertrophy is a key response to heart overload and a predictor of heart failure.
- Understanding distinct cellular phenotypes in hypertrophy is crucial for developing targeted therapies.
- Gene transcription patterns have been used, but proteomic analysis offers complementary insights.
Purpose of the Study:
- To develop and refine proteomic technologies for analyzing cardiac hypertrophy.
- To identify specific protein expression changes in a cell culture model of cardiac hypertrophy.
- To establish a general model for proteomic studies linking genomic sequences to protein expression.
Main Methods:
- Utilized two-dimensional polyacrylamide gel electrophoresis (2D PAGE) for proteome analysis.
- Developed improved in-gel digestion techniques for low-abundance proteins.
- Employed high-sensitivity mass spectrometry (MS), including MALDI-MS and LC-ion trap MS, for protein identification.
Main Results:
- Analyzed 2D gel patterns from cardiac myocytes with and without phenylephrine-induced hypertrophy.
- Identified eleven protein spots with statistically significant changes in abundance.
- Optimized peptide recovery using sodium dodecyl sulfate in digestion buffer and achieved subpicomole level protein identification.
Conclusions:
- The study successfully applied advanced proteomic techniques to a cardiac hypertrophy model.
- Established a robust methodology for identifying differentially expressed proteins in cardiac cells.
- The integrated approach provides a general model for correlating genomic data with proteomic expression patterns.
Abstract:
Hypertrophy of cardiac myocytes is a primary response of the heart to overload, and is an independent predictor of heart failure and death. Distinct cellular phenotypes are associated with hypertrophy resulting from different causes. These phenotypes have been described by others at the molecular level by analysis of gene transcription patterns. An alternative approach is the analysis of large-scale protein expression patterns (the proteome) by two-dimensional polyacrylamide gel electrophoresis. Realization of this goal requires the ability to rigorously analyze complex 2D gel images, efficiently digest individual gel isolated proteins (especially those expressed at low levels), and analyze the resulting peptides with high sensitivity for rapid database searches. We have undertaken to improve the technology and experimental approaches to these challenges in order to effectively study a cell culture model for cardiac hypertrophy. The 2D gel patterns for cell lysates from multiple samples of cardiac myocytes with or without phenylephrine-induced hypertrophy were analyzed and spots which changed in abundance with statistical significance were located. Eleven such spots were identified using improved procedures for in-gel digestion of silver-stained proteins and high-sensitivity mass spectrometry. The incorporation of low levels of sodium dodecyl sulfate into the digestion buffer improved peptide recovery. The combination of matrix-assisted laser desorption mass spectrometry for initial measurements and capillary liquid chromatography-ion trap mass spectrometry for peptide sequence determination yielded efficient protein identification. The integration of 2D gel image analysis and routine identification of proteins present in gels at the subpicomole level represents a general model for proteome studies relating genomic sequence with protein expression patterns.