Altered AADAC Modulates Trophoblast Invasion and Suggests a Potential Angiogenic Regulatory Role in Severe Preeclampsia

Preeclampsia (PE) is a serious pregnancy complication characterized by hypertension and organ dysfunction. Its pathogenesis involves impaired trophoblast invasion and inadequate spiral artery remodeling; however, the underlying molecular mechanisms remain unclear. This study investigated the role of arylacetamide deacetylase (AADAC) in PE and its effects on trophoblast function by analyzing placental tissues from 30 patients with PE and 15 controls. Exploratory RNA sequencing was performed on pooled placental samples from six patients with severe PE and six controls, and AADAC expression was validated by semi-quantitative PCR and Western blotting. HTR8/SVneo cells were exposed to cobalt chloride (CoCl₂) under hypoxia-mimicking conditions, and AADAC expression was manipulated by siRNA-mediated knockdown (KD) and overexpression (OE). RNA sequencing revealed increased <i>AADAC</i> expression in PE placentas (fold change > 2.0, raw <i>p</i> < 0.05). Although <i>AADAC</i> mRNA levels were elevated in PE tissues, protein levels were reduced. CoCl₂ exposure was associated with increased expression of AADAC and hypoxia-inducible factor-1 alpha (HIF-1α). Under hypoxia-mimicking conditions, <i>AADAC</i> silencing was associated with increased trophoblast invasion and tube formation, whereas <i>AADAC</i> overexpression reduced tube formation without significantly affecting invasion. These findings suggest that dysregulated, hypoxia-responsive AADAC expression influences trophoblast invasive and angiogenic behavior in preeclampsia.