NFAT5/TonEBP controls metabolic adaption and tone of pulmonary vascular smooth muscle cells in the hypoxic lung [normoxia vs hypoxia]

ABSTRACT: Hypoxia provokes adaptive responses of cells, which ensure their energy supply including the adjustment of the transcriptome to match their metabolism. In this context, we explored the transcriptional impact of nuclear factor of activated T-cells 5 (NFAT5) on the function of vascular smooth muscle cells (VSMC) in the hypoxic lung. Exposure to hypoxia induced a rapid nuclear translocation of NFAT5 in cultured murine VSMCs. SMC-specific ablation of Nfat5 (Nfat5(SMC-/-)) increases the systolic pressure in the right ventricle (RVSP) of the mouse heart and impairs its function upon exposure to hypoxia for 7 and 21 days. Analyses of the transcriptome of the lung revealed a robust increase in the expression genes attributed to mitochondrial respiration. Further analyses of hypoxia-exposed pulmonary artery VSMCs revealed that loss of Nfat5 stimulates the expression of multiple mitochondria-related genes encoding cytochrome oxidases while decreasing the expression of lactate dehydrogenase A (Ldha) and phosphofructokinase 3 (Pfkfb3). Both, inhibition of LDHA or PFKFB3 activity and loss of Nfat5 stimulated the mitochondrial production of reactive oxygen species (ROS) in hypoxic pulmonary artery VSMCs while scavenging of ROS normalized the RVSP values in hypoxia-exposed Nfat5(SMC-/-) mice. In summary, our findings suggest a crucial role for NFAT5 in adjusting the transcriptome of hypoxia-exposed pulmonary artery VSMCs to support an adequate glycolysis-centered metabolism. Loss of Nfat5 impairs this response thereby fueling the mitochondrial respiration and ROS production that amplifies the hypoxia-mediated constriction of pulmonary arteries.

ORGANISM(S): Mus musculus

PROVIDER: GSE178462 | GEO | 2021/11/26

REPOSITORIES: GEO