A. The expression of MiD49 and MiD51, are increased in PAH due to the downregulation of their regulatory microRNA, miR-34a-3p. This increase in MiD expression drives pathological mitochondrial fission by sequestering activated Drp1 to the outer mitochondrial membrane (OMM), cell proliferation and apoptosis resistance via PDGFR-α/β-Ras-Raf-Erk pathway.
B. In cancer, downregulation of miR-34a-3p leads to MiD upregulation which in turn drives mitochondrial fission by sequestering activated Drp1 to the outer mitochondrial membrane (OMM), cell proliferation and apoptosis resistance via Akt-mTOR-S6K axis.