Integrating single-cell RNA sequencing and transcriptome analysis to explore uric acid–related biomarkers and regulatory mechanisms in preeclampsia

Preeclampsia (PE) is a pregnancy-specific syndrome that occurs after 20 weeks of gestation. Abnormal uric acid metabolism may play a pivotal role in the onset and progression of PE. This research aimed to extensively analyze and pinpoint biomarkers related to uric acid in PE and elucidate their potential molecular mechanisms. Data related to PE and uric acid were obtained from the public databases. Biomarkers were selected and validated through differential expression analysis, machine learning algorithms, receiver operating characteristic (ROC) curves, and expression level validation. Moreover, a nomogram was applied to construct a uric acid-related predictive model for PE. Enrichment analysis, immune infiltration analysis, molecular regulatory network, drug prediction, and molecular docking were performed to further verify the regulatory roles of biomarkers. Furthermore, the expression patterns of biomarkers in core cells were investigated using dataset GSE173193. Finally, validation of biomarkers expression was performed by western- blotting and qRT-PCR. Overall, four biomarkers (ENG, JAK1, LEP, and SLC6A8) were identified as significantly associated with uric acid in PE. A predictive nomogram based on these biomarkers showed promising apparent diagnostic performance in the GSE35574 cohort. The biomarkers were significantly enriched in the “housekeeping genes”, “mitochondria”, and “signaling by Robo receptors”. Notably, JAK1 was positively correlated with gamma delta T cells, while SLC6A8 was negatively correlated with gamma delta T cells. Subsequently, 348 microRNAs (miRNAs) (like hsa-miR-4486) and 25 transcription factors (TFs) (like CTCF, TBP, and MAFK) were associated with the biomarkers. Molecular docking predicted favorable interactions for the reported biomarker-compound pairs. Moreover, ENG, JAK1, and SLC6A8 exhibited relatively high expression in extravillous trophoblasts (EVT). Finally, the results of qRT-PCR and Western blot showed that the mRNA and protein expressions of ENG, SLC6A8, and LEP in placental tissues from the PE group were higher than those in the control group, while the mRNA and protein expressions of JAK1 were lower in the placental tissues of the PE group compared to the control group, which is consistent with the expression patterns observed in the RNA sequencing (RNA-seq) datasets. Four uric acid-related biomarkers (ENG, JAK1, LEP, and SLC6A8) were identified in PE, providing preliminary molecular clues and a theoretical reference for further mechanistic exploration and the screening of potential therapeutic targets of PE.