Identification of molecular signatures in acute myocardial infarction based on integrative analysis of proteomics and transcriptomics

BACKGROUND

Myocardial infarction (MI) is one of the most serious cardiovascular diseases, characterized by a rapid and irreversible decline in myocardial function. Early detection of patients with MI and prolonging the optimal therapeutic window of acute myocardial infarction (AMI) are particularly important. This study aimed to identify the diagnostic biomarkers and novel therapeutic targets for acute myocardial infarction.

METHOD

We generated the AMI mouse models by ligating the proximal left anterior descending coronary artery. Six time points-Sham, AMI 10-min, 1-h, 6-h, 24-h, and 72-h-were chosen to examine the molecular changes that occur during the AMI process. RNA-seq and DIA-MS were performed on the infarcted left ventricular tissues of AMI mice at each time point. Co-expression pattern genes were screened from myocardial infarction samples at different time points by time-series analysis. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to examine these genes. Using the Interactive Gene/Protein Retrieval Tool (STRING) database, the protein-protein interaction network (PPI) was constructed and the hub genes were identified. In order to evaluate the diagnostic value of hub genes, a receiver operating characteristic (ROC) curve was constructed. An independent data set, GSE163772, confirmed the diagnostic value of hub genes further.

RESULT

We obtained the expression profiles at different time points after the occurrence of heart failure through high-throughput sequencing, and found 167 genes with similar expression patterns through time series analysis. The immune response and immune-related pathways had the greatest enrichment of these genes. Among them, Itgb2 Syk, Tlr4, Tlr2, Itgax, and Lcp2 may play key roles as hub genes. Combined with the results of proteomic analysis, it was found that the expression of Coro1a in both omics increased with time. The results of external validation showed that TLR2, ITGAX, and LCP2 had good predictive ability for AMI diagnosis.

CONCLUSION

Itgb2, Syk, Tlr4, Tlr2, Itgax, Lcp2 and Coro1a are considered to be the seven key genes significantly associated with AMI. Our results may provide potential targets for the prevention of adverse ventricular remodeling and the treatment of AMI.

Wip1 inhibits neutrophil extracellular traps to promote abscess formation in mice by directly dephosphorylating Coronin-1a

Neutrophil extracellular traps (NETs) participate in the rapid inhibition and clearance of pathogens during infection; however, the molecular regulation of NET formation remains poorly understood. In the current study, we found that inhibition of the wild-type p53-induced phosphatase 1 (Wip1) significantly suppressed the activity of Staphylococcus aureus (S. aureus) and accelerated abscess healing in S. aureus-induced abscess model mice by enhancing NET formation. A Wip1 inhibitor significantly enhanced NET formation in mouse and human neutrophils in vitro. High-resolution mass spectrometry and biochemical assays demonstrated that Coro1a is a substrate of Wip1. Further experiments also revealed that Wip1 preferentially and directly interacts with phosphorylated Coro1a than compared to unphosphorylated inactivated Coro1a. The phosphorylated Ser426 site of Coro1a and the 28-90 aa domain of Wip1 are essential for the direct interaction of Coro1a and Wip1 and for Wip1 dephosphorylation of p-Coro1a Ser426. Wip1 deletion or inhibition in neutrophils significantly upregulated the phosphorylation of Coro1a-Ser426, which activated phospholipase C and subsequently the calcium pathway, the latter of which promoted NET formation after infection or lipopolysaccharide stimulation. This study revealed Coro1a to be a novel substrate of Wip1 and showed that Wip1 is a negative regulator of NET formation during infection. These results support the potential application of Wip1 inhibitors to treat bacterial infections.

Neddylation of Coro1a determines the fate of multivesicular bodies and biogenesis of extracellular vesicles

Multivesicular bodies (MVBs) fuse with not only the plasma membranes to release extracellular vesicles (EVs) but also lysosomes for degradation. Rab7 participates in the lysosomal targeting of MVBs. However, the proteins on MVB that directly bind Rab7, causing MVB recruitment of Rab7 remain unidentified. Here, we show that Coro1a undergoes neddylation modification at K233 by TRIM4. Neddylated Coro1a is associated with the MVB membrane and facilitates MVB recruitment and activation of Rab7 by directly binding Rab7. Subsequently, MVBs are targeted to lysosomes for degradation in a Rab7-dependent manner, leading to reduced EV secretion. Furthermore, a decrease in neddylated Coro1a enhances the production of tumour EVs, thereby promoting tumour progression, indicating that neddylated Coro1a is an ideal target for the regulation of EV biogenesis. Altogether, our data identify a novel substrate of neddylation and reveal an unknown mechanism for MVB recruitment of Rab7, thus providing new insight into the regulation of EV biogenesis.

Emergent Role of Coronin-1a in Neuronal Signaling

The Coronin family of proteins were first noted for their role in pathogen-host interactions and for modulating actin dynamics. Recently, however, Coronins have been found in a greater variety of cell types, and novel roles for the Coronins within the nervous system have been discovered. In the immune system, Coronin-1a enables Mycobacterium tuberculosis to evade lysosomal destruction. This activity appears to be analogous to protection of the NGF-TrkA signaling endosome during sympathetic nervous system development that is required for survival signaling. Similarly, others have implicated Coronin-1a in GPCR signaling during the formation of excitatory connections in the central nervous system. Its role in multiple signaling pathways suggests that it may influence cross talk between key pathways (TrkA, GPCRs) during neurodevelopment. Here, we review the role of Coronin-1a in neural development and function.