This research aimed to predict the expression of cardiac ion channels in horses, important in studying cardiac health and disease, by analyzing existing RNA sequencing data from mixed tissue samples.

Objective of the Research

• The research aims to predict the expression of ion channels within the hearts of horses. Understanding this is crucial to studying normal heart function, as well as the underlying mechanisms of heart diseases, especially arrhythmias. There is currently little information on this subject within equine medicine.

Methodology

• The researchers used raw RNA sequencing data from normal horses that was collected from various previous studies (9 datasets in total). These were sourced from relevant databases such as ArrayExpress and the European Nucleotide Archive.
• This data was then reinterpreted and normalised based on the average expected gene expression weighted by the tissue proportion in each sample.
• The researchers used this data to predict the levels of ion channel expression specific to cardiac tissues.

Findings

• The study was able to predict the cardiac-specific expression of 91 ion channels, which include significant Na channels, K channels, and Ca-handling proteins.
• The observed results presented interesting findings that differed from what is commonly seen in human studies: the primary expressed Na channel was Na 1.4 (as opposed to Na 1.5), and the key Ca-handling proteins were RYR1, SERCA1, and CASQ1 (as opposed to RYR2, SERCA2 and CASQ2).
• The different expression levels suggest that there may be unique regulation mechanisms for these ion channels within horses, and understanding this may reveal new insights into the pathways leading to heart disease. The results may also provide important understanding into the mechanisms of arrhythmogenesis, or the development of irregular heart rhythms, in horses.

Conclusion

• This research provides important revelations about ion channel expression in equine cardiac tissues and begins to fill a gap in the understanding of equine cardiac electrophysiology. The differences in the data in comparison to human studies especially instigate further research into potentially varying regulatory mechanisms in horses. This could have significant implications for the study and treatment of equine cardiac pathologies, such as arrhythmias.