3-Mercaptopyruvate Sulfurtransferase (MPST) Regulates Mitochondrial Metabolism and Epithelial Differentiation in...

Early-life airway epithelial development relies on tightly coordinated mitochondrial metabolic programs, yet the pathways that govern normal epithelial maturation during this vulnerable developmental window remain poorly defined. Hyperoxia disrupts airway epithelial maturation, contributing to lung injury and airway remodeling in infants with bronchopulmonary dysplasia (BPD), underscoring the need to identify mitochondrial pathways that regulate early epithelial differentiation. 3-Mercaptopyruvate sulfurtransferase (MPST), a mitochondrial sulfur metabolism enzyme, supports mitochondrial metabolic and bioenergetic function, but its role in human airway epithelial development is unknown. In this study, we used neonatal patient-derived tracheal airway epithelial cells (nTAECs) in a three-dimensional air-liquid interface (ALI) model to show that hyperoxia reduces MPST protein abundance. To determine how MPST loss alters early epithelial differentiation and metabolic homeostasis we used RNAi to knock down MPST during ALI differentiation. MPST loss in nTAECs induced early (ALI day 3) transcriptomic shifts involving mitochondrial metabolic pathways, epithelial differentiation programs, and stress-response signature corresponding with decreased ciliated cell numbers during mid-differentiation phase (ALI day 7). Metabolic flux analysis revealed significantly reduced mitochondrial respiration without compensatory increase in glycolysis, indicative of disrupted metabolic flexibility. Together, these data show that MPST is essential for maintaining mitochondrial metabolic integrity necessary for normal airway epithelial development. Loss of MPST creates a developmental vulnerability that may contribute to hyperoxia-induced airway injury in neonates. Targeting MPST-dependent pathways could represent a new strategy to preserve airway health in infants at risk for BPD airway remodeling.

This study identifies MPST as a previously unrecognized regulator of neonatal airway epithelial development. In our neonatal patient-derived three-dimensional organotypic model, hyperoxia reduces MPST, and MPST loss alters mitochondrial metabolism and epithelial differentiation programs. These findings indicate that MPST deficiency contributes to mitochondrial dysfunction under hyperoxic conditions and highlight MPST-linked pathways as potential therapeutic targets to mitigate early-life airway injury and remodeling relevant to infants with bronchopulmonary dysplasia.