Xu C, Su X, Chen Y, Xu Y, Wang Z, Mo X.Ital J Pediatr. 2020 May 19;46(1):64. doi: 10.1186/s13052-020-00831-6.PMID: 32430045 Free PMC article.
Objective: Patent ductus arteriosus (PDA) is a congenital heart defect with an unclear etiology that occurs commonly among newborns. Adequately understanding the molecular pathogenesis of PDA can contribute to improved treatment and prevention. Plasma proteins may provide evidence to explore the molecular mechanisms of abnormal cardiac development.
Methods: Isobaric tags for relative and absolute quantitation (iTRAQ) proteomics technology was used to measure different plasma proteins in PDA patients (n = 4) and controls (n = 4). The candidate protein was validated by ELISA and Western blot (WB) assays in a larger sample. Validation of the location and expression of this protein was performed in mouse heart sections.
Results: There were three downregulated proteins and eight upregulated proteins identified in the iTRAQ proteomics data. Among these, protein disulfide-isomerase A6 (PDIA6) was further analyzed for validation. The plasma PDIA6 concentrations (3.2 ± 0.7 ng/ml) in PDA patients were significantly lower than those in normal controls (5.8 ± 1.2 ng/ml). In addition, a WB assay also supported these results. PDIA6 was widely expressed in mouse heart outflow tract on embryonic day 14.5.
Conclusion: Plasma proteomics profiles suggested novel candidate molecular markers for PDA. The findings may allow development of a new strategy to investigate the mechanism and etiology of PDA.
Fig. 1 Volcano plot of proteins detected by iTRAQ among PDA patients and controls. The green dot represents decreased protein levels (p < 0.05 and fold-change< 0.5), and the red dot represents increased protein levels (p < 0.05 and fold-change> 2.0)
Fig. 2 PDIA6 protein was measured by ELISA and WB in PDA patients and controls. a, ELISA was used to examine each subject’s plasma levels of PDIA6. N = 96 PDA patients and N = 96 controls. b, WB was performed to compare PDIA6 expression in plasma samples from PDA patients and controls. ELISA and WB assays were both performed three times
Fig. 3 Representative IF picture showing the location and expression of PDIA6 in mouse heart tissue on E14.5. Blue indicates the nucleus, and green indicates PDIA6. The experiment was performed three times. Scar bar = 100 μm