Identification and functional validation of P4HA1 and INHA as hypoxia-responsive biomarkers in preeclampsia

Preeclampsia (PE) is a life-threatening pregnancy disorder wherein placental hypoxia contributes significantly to its pathogenesis. This study aimed to identify and characterize hypoxia-related biomarkers for PE and to evaluate their potential value.

We analyzed the GSE75010 and GSE54618 datasets by weighted gene co-expression network analysis (WGCNA) to identify gene modules associated with PE. GO and KEGG enrichment analyses were performed, followed by intersection with a known hypoxia-related gene set and construction of a protein-protein interaction network. A two-gene nomogram (P4HA1 and INHA) was established using the GSE75010 dataset, and its diagnostic value was evaluated by area under the curve (AUC) and calibration curves in the validation cohorts GSE60438 and GSE25906. For experimental validation, RT-qPCR, Western blot, and immunohistochemistry assessed P4HA1 and INHA expression in human placentas. Finally, an L-NAME-induced PE mouse model and a CoCl₂-induced trophoblast hypoxia model further verified their expression and function.

We identified P4HA1 and INHA as key genes. The two-gene nomogram showed moderate diagnostic performance in validation cohorts. Both genes were elevated in PE placentas and localized to trophoblasts. Hypoxia upregulated their expression in vivo and in vitro. Knockdown of either gene partially restored trophoblast migration, invasion, and proliferation under hypoxia, and combined silencing produced a greater recovery.

This study identified P4HA1 and INHA as key hypoxia-responsive genes in PE, offering a new molecular perspective on disease pathogenesis.