Junfang Wu

Both the Apolipoprotein E (ApoE) genotype and apolipoprotein (Apo) profiling are closely associated with the risk of coronary heart disease (CHD). However, it remains unclear whether APOE genotypes modulate the distribution of Apos and whether such regulation differs between young and elderly CHD patients. The present study aims to investigate the effects of APOE genotypes on the levels of plasma Apos in both young and elderly CHD patients. Two datasets were analyzed. Dataset 1 included 293 CHD patients with APOE genotyping. The quantification of 4 APOE isoform-specific peptides and 16 Apos was simultaneously measured in plasma using liquid chromatography-mass spectrometry. Dataset 2 comprised 3821 CHD participants from UK Biobank, for whom Apo levels were obtained through Olink proteomics. Selected Apos identified in dataset 1 were independently validated in dataset 2. We developed a robust method for simultaneous quantification of APOE isoforms and Apos in human plasma. APOE genotype results from liquid chromatography-mass spectrometry were fully consistent with those from the TaqMan assay in all patients. Among the measured Apos, the levels of ApoL1 were significantly decreased in elderly CHD patients, which were independently validated in the UK Biobank cohort, particularly in those carrying APOΕ ε3 and ε4 alleles. Mediation analysis revealed that ApoL1 statistically mediated the association between age and CHD status. Our results suggested that APOE polymorphisms affect the plasma Apo profiles and that ApoL1 is associated with older CHD patients carrying the APOE ε3 and ε4 genotypes.

Myocardial ischemia/reperfusion (I/R) injury is a major determinant of infarct size and clinical outcome, yet effective therapies remain limited. Although metabolic remodeling is central to I/R pathology, the contribution of nucleotide biosynthesis remains unclear. Here, we identify CAD, the multifunctional rate-limiting enzyme of de novo pyrimidine biosynthesis, as a previously unrecognized regulator of myocardial reperfusion injury. CAD activation exacerbated cardiomyocyte death during simulated I/R, whereas CAD knockdown or pharmacological inhibition was protective in vitro. Mechanistically, CAD enhanced dihydroorotate dehydrogenase (DHODH)-dependent electron transfer, increased the CoQH?/CoQ ratio, and promoted complex I reverse electron transport (RET), thereby amplifying mitochondrial ROS. In parallel, CAD suppressed de novo purine synthesis, causing purine insufficiency, DIS3L-dependent RNA decay, and cytosolic ROS. Importantly, cardiomyocyte-specific CAD deletion protected against cardiac I/R injury in vivo. Together, these findings establish CAD as a metabolic hub linking nucleotide flux to dual-compartment ROS signaling and identify nucleotide metabolism as a therapeutic vulnerability in myocardial I/R injury.

Kynurenine to tryptophan ratio (KTR), which serves as an indicator for evaluating indoleamine-2,3-dioxygenase activity and inflammation, has been reported to be linked with cardiovascular incidences. However, its correlation with cardiovascular outcomes in patients suffering from heart failure (HF) remains to be explored. The objective of this study was to investigate the prognostic value of KTR in HF. The concentration of tryptophan and kynurenine were quantified by liquid chromatography-tandem mass spectrometry, and the KTR value was calculated in a population of 3150 HF patients. The correlation between plasma KTR levels and the occurrence of adverse cardiovascular events was evaluated for its prognostic value. We also assessed the role of KTR in addition to the classic inflammatory biomarker hypersensitive C-reactive protein (hs-CRP) in different subtypes of HF. We found that increased KTR levels were associated with an elevated risk and severity of the primary endpoints in different subtypes of HF. The simultaneous evaluation of KTR and hs-CRP levels enhanced risk categorization among HF patients. Furthermore, the KTR index presented complementary prognostic value for those HF patients with low-grade inflammation (hs-CRP ≤ 6 mg/L). Our results indicated plasma KTR is an independent risk factor for cardiovascular events. Plasma KTR levels in patients with HF can provide both concurrent and complementary prognostic value to hs-CRP.

A robust LC-MS/MS method for simultaneously quantifying apolipoproteins and lipoprotein (a) has been developed.

Phenylacetylglutamine (PAGln) is an amino acid derivate that comes from the amino acid phenylalanine. There are increasing studies showing that the level of PAGln is associated with the risk of different cardiovascular diseases. In this review, we discussed the metabolic pathway of PAGln production and the quantitative measurement methods of PAGln. We summarized the epidemiological evidence to show the role of PAGln in diagnostic and prognostic value in several cardiovascular diseases, such as heart failure, coronary heart disease/atherosclerosis, and cardiac arrhythmia. The underlying mechanism of PAGln is now considered to be related to the thrombotic potential of platelets via adrenergic receptors. Besides, other possible mechanisms such as inflammatory response and oxidative stress could also be induced by PAGln. Moreover, since PAGln is produced across different organs including the intestine, liver, and kidney, the cross-talk among multiple organs focused on the function of this uremic toxic metabolite. Finally, the prognostic value of PAGln compared to the classical biomarker was discussed and we also highlighted important gaps in knowledge and areas requiring future investigation of PAGln in cardiovascular diseases.