Chronic Hypoxia-Induced Reprogramming of Smooth Muscle Cells: Insights into Transcription Factors, Cellular Stresses,...

Background/Objectives: Chronic hypoxia promotes a shift in smooth muscle cells from a quiescent, contractile state to a highly proliferative phenotype, contributing to persistent vascular remodeling. This study examines primary human esophageal smooth muscle cells (HEsSMCs) exposed to hypoxia mimics, desferoxamine (DFO) and dimethyloxallyl glycine (DMOG), and their interaction with angiotensin II (AngII). Methods: We utilized HEsSMCs to assess the effects of DFO, DMOG, and AngII through MTT metabolic activity assays, Western blotting analyses, and flow cytometry to evaluate various cellular functions. Additionally, we reanalyzed the public RNA sequencing dataset GSE193817 to explore the contextual influences of DFO-induced responses in HEsSMCs. Results: Our findings indicate that both DFO and DMOG stabilize hypoxia-inducible factor-1 alpha proteins at different time intervals, revealing distinct cell cycle profiles and varied protein responses. DFO was shown to increase mitochondrial reactive oxygen species (ROS) while simultaneously suppressing cytosolic ROS, suggesting the involvement of multiple pathways beyond those activated by hypoxic stress. Flow cytometry analysis revealed that DFO triggers late-stage apoptosis, along with increases in overall hypoxia, ROS, autophagy, lipid peroxidation, and mitochondrial membrane depolarization in HEsSMCs. Furthermore, AngII was observed to inhibit the activation of nuclear factor-κB induced by DFO. The analysis of the GSE193817 dataset illuminated the transitional dynamics between quiescent and proliferative states in smooth muscle cells, indicating that AngII signaling is modular and does not simply counteract DFO-induced effects. Conclusions: This research enhances our understanding of hypoxia and ROS responses in HEsSMCs and underscores the potential for personalized medicine informed by sequencing data.