Developments in the fields of genomics, transcriptomics, and proteomics have the potential to further define complex diseases; however, in the study of stroke, there has been variable data generated. While proteomics holds the promise of large-scale, identification of individual proteins, current knowledge is hampered by limitations including cost of high-throughput analysis and difficulty in identification of low abundant proteins.11
Conversely, the human genome-wide association studies have analyzed 500,000 SNPs in large numbers of subjects and genetically defined diverse diseases and risk factors.12–14
There has been more limited studies of large-scale gene expression profiling in comprehensive cohorts focused on risk factors for atherothrombotic disease;15
but such findings have been reported in oncological studies16–19
demonstrating prediction of oncological prognosis and classifications for pre-cancerous disease states.20
While there is less data in vascular disease, there is growing information concerning the transcriptome in this setting. For example, gene expression from leukocytes in patients with sickle cell disease is consistent with increased oxidation and inflammation.21
However, a major limitation of previous cardiovascular gene expression studies is their small size and the inherent problem of obtaining the appropriate tissue needed for analysis.
Another area of gene expression that is being directed towards study of blood derived transcripts is the field of micro RNAs (miRNAs); recently discovered small RNAs that play an important role in the negative regulation of gene expression by suppressing protein translation. The expressionof many miRNAs is usually specific to a tissue or developmentalstage, and the miRNA expression pattern is altered during thedevelopment of many diseases.22, 23
Specifically, they are miRNAs that participatein the regulation of various biological functions in numerouseukaryotic lineages, including mammals.24–26
More than 800 human miRNAs have been cloned with bioinformatic predictions indicating that mammalian miRNAs can regulate approximately 30% of all protein-coding genes.27–29
Micro RNAs have been found in whole blood and may reflect disease; they are known to influence redox sensitive enzymes and, hypothetically, could be altered in an inflammatory setting.