Peptidylarginine Deiminase 2 Knockout Improves Survival in hemorrhagic shock

BACKGROUND The peptidylarginine deiminase (PAD) family converts arginine into citrulline through protein citrullination. PAD2 and PAD4 inhibitors can improve survival in hemorrhagic shock (HS). However, the impact of isoform-specific PAD inhibition in improving survival has not been studied. In this study, we utilize selective Pad2 knockout mice to elucidate loss of function of PAD2 leads to pro-survival effect in HS. METHODS HS: Pad2 and wild-type (WT) mice (n = 5/group) were subjected to lethal HS (55% volume hemorrhage). Survival was monitored over 7 days. Myocardial infarction (MI): Pad2 and WT mice (n = 9/group) were subjected to MI by permanent LAD ligation to examine the effect of ischemia on the heart. After 24 h cardiac function and infarct size were measured. RESULTS HS: Pad2 mice demonstrated 100% survival compared with 0% for WT mice (P = 0.002). In a sub-lethal HS model, cardiac β-catenin levels were higher in Pad2 compared with WT after 24 h. MI: WT mice demonstrated larger MI (75%) compared with Pad2 (60%) (P < 0.05). Pad2 had significantly higher ejection fraction and fractional shortening compared with WT (P