Systemic Hypoxemia Induces Cardiomyocyte Hypertrophy and Right Ventricular Specific Induction of Proliferation

A recent study suggests that systemic hypoxemia in adult male mice can induce cardiac myocytes to proliferate. The goal of the present experiments was to confirm these results, provide new insights on the mechanisms that induce adult cardiomyocyte cell cycle re-entry, and to determine if hypoxemia also induces cardiomyocyte proliferation in female mice. We also analyzed gene expression using data obtained from RNAseq of ventricular heart tissue from male and female mice subjected to either normoxia or hypoxia. Male and female mice in the Hypoxia group were placed in a hypoxia chamber and the oxygen was lowered by 1% every day for 14 days to reach 7% oxygen. The animals remained in 7% oxygen for 2 weeks before terminal studies. Mice in the normoxia group remained at room air (20.9% oxygen) for 4 weeks before terminal studies. Hearts were collected and snap frozen in liquid nitrogen. Frozen ventricular samples of the hearts were used in RNAseq. We performed comparative gene expression profiling analysis of RNA-seq data on male and female mice subjected to either normoxia or hypoxia.