Genetic and hypoxic alterations of the micro <scp>RNA</scp> ‐210‐ <scp>ISCU</scp> 1/2 axis promote iron–sulfur deficiency and pulmonary hypertension

Iron-sulfur (Fe-S) clusters are essential for mitochondrial metabolism, but their regulation in pulmonary hypertension (PH) remains enigmatic. We demonstrate that alterations of the miR-210-ISCU1/2 axis cause Fe-S deficiencies in vivo and promote PH. In pulmonary vascular cells and particularly endothelium, hypoxic induction of miR-210 and repression of the miR-210 targets ISCU1/2 downregulated Fe-S levels. In mouse and human vascular and endothelial tissue affected by PH, miR-210 was elevated accompanied by decreased ISCU1/2 and Fe-S integrity. In mice, miR-210 repressed ISCU1/2 and promoted PH. Mice deficient in miR-210, via genetic/pharmacologic means or via an endothelial-specific manner, displayed increased ISCU1/2 and were resistant to Fe-S-dependent pathophenotypes and PH. Similar to hypoxia or miR-210 overexpression, ISCU1/2 knockdown also promoted PH.