Investigation of Heart Lipids Changes in Acute β-AR activation Induced Sudden Cardiac Death by Time-of-Flight Secondary Ion Mass Spectrometry
Sudden cardiac death (SCD), one of the most common causes of human death, has become a major health and social problem. The postmortem diagnosis and prevention of SCD remain primary challenges in medical community due to the lack of reliable diagnostic biomarkers. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a sensitive surface analysis technique for analyzing tissue slices with high spatial resolution. Here, ToF-SIMS followed by principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were employed to study the SCD mouse myocardium samples and obtain high resolution chemical mappings and mass spectra. Distinction between normal control (NC) and acute β-adrenergic receptor (β-AR) activation induced SCD groups was primarily due to changes of diacylglycerols (DAG), phosphatidylcholine (PC), lysophosphatidylcholine (LysoPC) and sphingomyelin (SM) in positive mode. Meanwhile, chemical mapping of myocardium showed the different lipid distributions in SCD mouse myocardium. The metabolite alterations in mice models were further verified by analyzing the heart tissue sections of a 28-year-old woman died from isoprenaline injection. This pilot study demonstrated the significance of ToF-SIMS in characterizing lipid variations of SCD heart tissues and might contribute to the postmortem diagnosis of SCD, the discovery of molecule candidates to discriminate the progression of SCD and the understanding of its potential postmortem diagnostic significance of SCD.