Hypoxic activation of glucose-6-phosphate dehydrogenase controls the expression of genes involved in the pathogenesis of pulmonary hypertension through the regulation of DNA methylation.

Abstract

Metabolic reprogramming is considered important in the pathogenesis of the occlusive vasculopathy observed in pulmonary hypertension (PH). However, the mechanisms that link reprogrammed metabolism to aberrant expression of genes, which modulate functional phenotypes of cells in PH, remain enigmatic. Herein, we demonstrate that, in mice, hypoxia-induced PH was prevented by glucose-6-phosphate dehydrogenase deficiency (G6PDDef), and further show that established severe PH in Cyp2c44-/- mice was attenuated by knockdown with G6PD shRNA or by G6PD inhibition with an inhibitor (N-ethyl-N'-[(3β,5α)-17-oxoandrostan-3-yl]urea, NEOU). Mechanistically, G6PDDef, knockdown and inhibition in lungs: 1) reduced hypoxia-induced changes in cytoplasmic and mitochondrial metabolism, 2) increased expression of Tet methylcytosine dioxygenase 2 (Tet2) gene, and 3) upregulated expression of the coding genes and long noncoding (lnc) RNA Pint, which inhibits cell growth, by hypomethylating the promoter flanking region downstream of the transcription start site. These results suggest functional TET2 is required for G6PD inhibition to increase gene expression and to reverse hypoxia-induced PH in mice. Furthermore, the inhibitor of G6PD activity (NEOU) decreased metabolic reprogramming, upregulated TET2 and lncPINT, and inhibited growth of control and diseased smooth muscle cells isolated from pulmonary arteries of normal individuals and idiopathic-PAH patients, respectively. Collectively, these findings demonstrate a previously unrecognized function for G6PD as a regulator of DNA methylation. These findings further suggest that G6PD acts as a link between reprogrammed metabolism and aberrant gene regulation and plays a crucial role in regulating the phenotype of cells implicated in the pathogenesis of PH, a debilitating disorder with a high mortality rate.

• Authors: Sachindra Raj Joshi, Atsushi Kitagawa, Christina Jacob, Ryota Hashimoto, Vidhi Dhagia, Amrit Ramesh, Connie Zheng, Hui Zhang, Allan Jordan, Ian Waddell, Jane Leopold, Cheng-Jun Hu, Ivan F McMurtry, Angelo D'Alessandro, Kurt R Stenmark, Sachin A Gupte
• Journal: American journal of physiology. Lung cellular and molecular physiology (Am J Physiol Lung Cell Mol Physiol) Vol. 318 Issue 4 Pg. L773-L786 (04 01 2020) ISSN: 1522-1504 [Electronic] United States
• PMID: 32159369 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• RNA, Long Noncoding
• Glucosephosphate Dehydrogenase
• Cytochrome P450 Family 2

Topics

• Animals
• Cell Proliferation (genetics)
• Cytochrome P450 Family 2 (genetics)
• DNA Methylation (genetics)
• Female
• Gene Expression (genetics)
• Gene Expression Regulation (genetics)
• Glucosephosphate Dehydrogenase (genetics)
• Hypertension, Pulmonary (genetics)
• Hypoxia (genetics)
• Lung (metabolism)
• Male
• Mice
• Muscle, Smooth, Vascular (metabolism)
• Myocytes, Smooth Muscle (metabolism)
• Phenotype
• Pulmonary Artery (metabolism)
• RNA, Long Noncoding (genetics)
• Up-Regulation (genetics)