Protein levels of 2 genes in plasma exosomes may be potential markers for myocardial infarction (MI), according to results of a study published in the Journal of Cardiology.
Patients with MI (n=30) and age- and gender-matched healthy controls (n=30) were recruited from Shanghai Xuhui Central Hospital in China between January and March 2020. Study participants were assessed for levels of low-density lipoprotein receptor (LDLR), apolipoprotein A V (APOA5), and cardiac troponin T (cTnT) in plasma-derived exosomes.
Participants in the MI and control cohorts had a mean age of 61.15±10.33 and 59.73±11.50 years; total cholesterol was 4.52±1.15 and 4.23±0.71 mmol/L; high-density lipoprotein cholesterol was 1.05±0.23 and 1.29±0.31 mmol/L; and triglycerides was 1.82±0.66 and 1.51±0.94 mmol/L, respectively. There were 18 men and 12 women in both groups.
The MI cohort had lower levels of LDLR and APOA5 protein (both P <.001) and cTnT was 10 times higher in plasma exosomes of the MI cohort than in the control group (P <.001).
The morphology of the plasma exosomes of the patients with MI were observed to be round compared with the ring-shaped exosomes identified among controls. In addition, exosomes from patients with MI were larger (median diameter, 106.6±1.5 vs 65.0±5.4 nm; P <.01) and the concentration of exosomes 30 to150 nm in diameter was higher (3.27E09±8.64E07 vs 1.61E09±1.01E08 particles/ml; P <.01).
An in vitro experiment found similar trends, in which treating myocadiac cells with an oxygen-glucose deprivation method induced apoptosis and decreased LDLR and APOA5 expression. A normal phenotype was rescued and LDLR and APOA5 levels were increased after treating cells with exosomes isolated from healthy individuals.
This study was limited by its small sample size and heterogenous study population. These findings should be confirmed in an independent cohort.
“The results together suggest that exosomal APOA5 and LDLR are intimately associated with MI, and thereby have the potential to function as diagnostic markers of MI,” the study authors wrote.
He Y, Gu X, Hu Y, et al. Low-density lipoprotein receptor and apolipoprotein A 5, myocardial infarction biomarkers in plasma-derived exosomes. J Cardiol. Published online January 14, 2022. doi:10.1016/j.jjcc.2021.10.020