title: Alpha-1 antitrypsin inhibits caspase-1 and protects from acute myocardial ischemia-reperfusion injury.
abstract: Alpha-1-antitrypsin (AAT) possesses anti-inflammatory and tissue-protective properties. Here, we studied the effects of exogenously administered AAT on caspase-1 activity and on the outcome of ischemia-reperfusion injury (I/R) in a mouse model of acute myocardial infarction (AMI). Adult male mice underwent 30 min of coronary artery ligation followed by reperfusion and were randomly assigned to receive clinical-grade AAT or albumin at reperfusion. Infarct size was evaluated after 1 and 7 days. Caspase-1 activity was measured in homogenates of heart tissue. Left ventricular (LV) end-diastolic diameter (EDD) and end-systolic diameter (ESD) were measured and LV fractional shortening (FS) and ejection fraction (EF) were calculated using transthoracic echocardiography. The effect of AAT on caspase-1 activity was determined in cultures of mouse HL-1 cardiomyocytes stimulated with LPS and triggered with nigericin or when HL-1 cells were exposed to simulated ischemia. AAT-treated mice had significantly smaller infarct sizes (-30% day 1 and -55% day 7) compared with mice treated with albumin. AAT treatment resulted in >90% reduction in caspase-1 activity in homogenates of hearts 24h after I/R. Seven days after AMI, AAT-treated mice exhibited a >90% smaller increase in LVEDD and LVESD and smaller reduction in LVEF. The increase in caspase-1 activity in HL-1 cells induced by LPS and nigericin or following exposure to simulated ischemia was reduced by >80% and AAT similarly reduced cell death by >50%. In conclusion, exogenous administration of clinical grade AAT reduces caspase-1 activity in the ischemic myocardium leading to preservation of viable myocardium and prevention of adverse cardiac remodeling.
authors: VCU Pauley Heart Center, Virginia Commonwealth University, Richmond, VA, USA.
authors: Stefano
authors: S
authors: Toldo
authors: Ignacio M
authors: IM
authors: Seropian
authors: Eleonora
authors: E
authors: Mezzaroma
authors: Benjamin W
authors: BW
authors: Van Tassell
authors: Fadi N
authors: FN
authors: Salloum
authors: Eli C
authors: EC
authors: Lewis
authors: Norbert
authors: N
authors: Voelkel
authors: Charles A
authors: CA
authors: Dinarello
authors: Antonio
authors: A
authors: Abbate