α-1-antitrypsin inhibits acute liver failure in mice.
Acute liver failure remains a critical clinical condition, with high mortality rates, and increased apoptosis of hepatocytes represents a key event in the cause of liver failure. Alpha-1-antitrypsin (AAT) is synthesized and secreted mainly by hepatocytes, and plasma purified AAT is used for augmentation therapy in patients with AAT deficiency. Because AAT therapy exerts antiinflammatory and immune modulatory activities in various experimental models, and it was recently suggested that AAT exerts antiapoptotic activities, we aimed to explore whether administration of AAT may represent a therapeutic strategy to treat acute liver failure in mice. Well-established preclinical models of acute liver failure such as the Jo2 FAS/CD95 activating model and models of acetaminophen and α-amanitin poisoning were used. Therapeutic effects of AAT were evaluated by monitoring animal survival, histopathological changes, measurement of caspase activity, and serum cytokine levels. Systemic treatment with AAT significantly decreased Jo2-induced liver cell apoptosis and prolonged survival of mice. Native and oxidized (lacking elastase inhibitory activity) forms of AAT were equally effective in preventing acute liver injury and showed direct inhibition of active caspase-3 and -8 in liver homogenates and in a cell-free system in vitro. Concomitantly, mice treated with AAT showed significantly lower serum levels of tumor necrosis factor alpha (TNF-α), which also paralleled the reduced activity of ADAM17 (TACE). Noticeably, the increased survival and a reduction of apoptotic hepatocytes were also observed in the α-amanitin and acetaminophen-induced liver injury mouse models.


CONCLUSIONS
Our data suggest that systemic administration of AAT can be a promising therapy to treat acute liver failure and clinical studies to explore this treatment in humans should be initiated.
Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany; Chronic Infection and Cancer Group, Helmholtz Center for Infection Research, Braunschweig, Germany; Division of Translational Gastrointestinal Oncology, Department of Internal Medicine I, University Hospital Tuebingen, Tübingen, Germany.
Nils
N
Jedicke
Nina
N
Struever
Nupur
N
Aggrawal
Tobias
T
Welte
Michael P
MP
Manns
Nisar P
NP
Malek
Lars
L
Zender
Sabina
S
Janciauskiene
Torsten
T
Wuestefeld
D051722:ADAM Proteins / Q000037:antagonists & inhibitors / Q000097:blood; D000072198:ADAM17 Protein; D000818:Animals; D061945:Caspase Inhibitors / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D008099:Liver / Q000201:enzymology / Q000473:pathology; D017114:Liver Failure, Acute / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D015842:Serine Proteinase Inhibitors / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D000515:alpha 1-Antitrypsin / Q000494:pharmacology / Q000627:therapeutic use*
D061945:Caspase Inhibitors; D015842:Serine Proteinase Inhibitors; D014409:Tumor Necrosis Factor-alpha; D000515:alpha 1-Antitrypsin; D020169:Caspases; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; C000606463:Adam17 protein, mouse