Heme-Oxygenase 1 is a Master Regulator of Cell Fate Following Oxidative Stress Response in Endothelial Cells

ABSTRACT: Purpose: Excess oxidative stress (OS) impairs endothelial function and plays an important role in vascular diseases, diabetes, and neuronal disorders. Several consequences of OS including cell recovery and apoptosis have been described previously. In this study, we report systems model of the temporal dynamics of the oxidative stress response in Human Umbilical Vein Endothelial Cells (HUVECs) and characterize HMOX1 as a master regulator in orchestrating the response to oxidative stress. Methods: Following stress induction by hydrogen peroxide (HP), we carried out dose-dependent phenotypic assays and time series measurements of transcripts in HUVECs. To explore the role of HMOX1, HUVECs were transfected with scrambled siRNA or si-HMOX1 and then treated with hydrogen peroxide. Total RNA was collected from Scrambled-untreated, scrambled-H2O2, and si-HMOX1-H2O2 samples for RNAseq. Novel findings were validated by qPCR and functional assays. Results: In this study we have identified three phases of stress response (acute response from 1-2 hours, the transition from 4-6 hours, and the chronic stress response from 8-16 hours). We observe stable cell cycle arrest and impaired DNA replication/repair from 8-16 hours along with and increased resistance to apoptosis from 2-16 hours. Knockdown of HMOX1 prior to HP treatment releases the resistance to apoptosis. Similarly, many cellular processes switch their direction of regulation in HMOX1 deficient cells upon HP treatment (i.e. autophagy, mitochondria, cell surface signaling, expression of histone modifying enzymes and long-noncoding RNAs etc). Conclusions: Endothelial cell fate decisions are critically important for vascular health. In this study we provide a temporal model characterizing the transition from the acute stress response to the chronic response. The nexus of cell function and dysfunction is characterized by the concurrent activation of survival and death pathways. We explore the master regulatory role of HMOX1 and identify novel mechanisms by which HMOX1 may regulate cell fate decisions.

ORGANISM(S): Homo sapiens

PROVIDER: GSE72991 | GEO | 2021/09/05

REPOSITORIES: GEO