Mir-15 Micro RNA Precursor Family - Neonatal Cardiomyocyte Arrest

Neonatal Cardiomyocyte Arrest

Postnatal heart development sees the upregulation of multiple miR-15 family members. In particular, miR-195, when found at higher levels than normal in the developing heart, has been identified as a factor that may cause heart abnormalities in newborns. This has been linked to premature cell cycle arrest, through impaired proliferation of heart muscle fibres and through repressed mitotic gene expression. An accumulation of cardiac muscle fibres sees a consequent block in the transition between the pre-mitotic/G2 phase and mitotic phase of the cell cycle, with postnatal inhibition of the miR-15 family inducing cardiac muscle fibres to enter mitosis. miR-195 overexpression is further associated with cellular hypertrophy.