Measurement of oxidized lipoprotein (a) in patients with acute coronary syndromes and stable coronary artery disease by 2 ELISAs: Using different capture antibody against oxidized lipoprotein (a) or oxidized LDL

Genome-wide DNA methylome alterations in acute coronary syndrome

Acute coronary syndrome (ACS) is a common disease with high mortality and morbidity rates. The methylation status of blood DNA may serve as a potential early diagnosis and prevention biomarker for numerous diseases. The present study was designed to explore novel genome-wide aberrant DNA methylation patterns associated with ACS. The Infinium HumanMethylation450 assay was used to examine genome-wide DNA methylation profiles in 3 pairs of ACS and control group samples. Epigenome-wide DNA methylation, genomic distribution, Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The results were confirmed using methylation-specific polymerase chain reaction (MSP) and Sequenom MassARRAY analyses in ACS, stable coronary artery disease (SCAD) and control samples. A total of 11,342 differentially methylated (DM) 5′-C-phosphate-G-3′ (CpG) sites were identified, including 8,865 hypomethylated and 2,477 hypermethylated CpG sites in the ACS group compared with the control samples. They varied in frequency across genomic compartments, but were particularly notable in gene bodies and shores. The results of GO term and KEGG pathway enrichment analyses revealed that the methylated genes were associated with certain biological processes and pathways. Despite the considerable variability in methylation data, the candidate selected possessed significant methylation alteration in mothers against decapentaplegic homolog 3 (SMAD3) transcription start site 155 (Chr1:67356838-Chr1:67356942). MSP analysis from 81 ACS samples, 74 SCAD samples and 53 healthy samples, and Sequenom MassARRAY analysis, confirmed that differential CpG methylation of SMAD3 was significantly corrected with the reference results of the HumanMethylation450 array. The data identified an ACS-specific DNA methylation profile with a large number of novel DM CpG sites, some of which may serve as candidate markers for the early diagnosis of ACS.

Antioxidized LDL antibodies are associated with different metabolic pathways in patients with atherosclerotic plaque and type 2 diabetes

OBJECTIVE

Oxidized lipoproteins and antioxidized LDL antibodies (antioxLDL abs) have been detected in human plasma and atherosclerotic lesions. The principle aim of this study was to analyze the possible relationship between IgG and IgM antioxLDL abs and factors involved in different metabolic pathways (inflammation, lipid metabolism, apoptosis, and cell cycle arrest profile) in the occluded popliteal artery (OPA) compared with the femoral vein (FV).

RESEARCH DESIGN AND METHODS

Fifteen patients with advanced atherosclerosis and type 2 diabetes undergoing lower limb amputation participated in this study. Each patient had OPA and FV biopsy specimens and peripheral arterial occlusive disease. By real-time PCR, gene expression was analyzed from the OPA and FV specimens, and antioxLDL ab levels were measured by specific enzyme-linked immunosorbent assay.

RESULTS

The OPA and FV showed a positive correlation between only IgM antioxLDL ab levels and the expression of genes involved in different metabolic pathways, including inflammation (TFPI), apoptosis (BAX, caspase 3, AKT1), plaque disruption (MMP2 and MMP10), lipid metabolism (SCARB1, PPARg), and cell turnover (CDKN1A), and genes for transcription and growth factors (NFkB and VEGFA, respectively).

CONCLUSIONS

The results show that gene expression in the metabolic pathways (apoptosis, lipid metabolism, and inflammation) in the OPA and FV are directly related to the levels of IgM antioxLDL abs.

Percutaneous coronary intervention results in acute increases in native and oxidized lipoprotein(a) in patients with acute coronary syndrome and stable coronary artery disease

OBJECTIVE

To investigate possible changes of native and oxidized lipoprotein(a) [ox-Lp(a)] levels after percutaneous coronary intervention (PCI).

DESIGN AND METHODS

Lp(a), ox-Lp(a), and Lp(a) immune complexes (IC) and autoantibody levels were studied in 111 patients with acute coronary syndrome (ACS) and 68 patients with stable coronary artery disease (CAD) before and after PCI.

RESULTS

Compared with pre-PCI, Lp(a), ox-Lp(a), and Lp(a)-IC levels acutely increased, while the autoantibody decreased in both the ACS and stable CAD patients. They all returned toward baseline by 1 to 2 days. The absolute change of ox-Lp(a) was found positively related with both the diameter of stenosis (R=0.273, P=0.004) and the number of vessel disease (R=0.312, P=0.001) in the ACS patients, while not in the stable CAD patients.

CONCLUSION

PCI results in acute plasma increases of ox-Lp(a) and Lp(a). Ox-Lp(a) may be present in ruptured or permeable plaques and be released into the circulation by PCI.