Carbonic anhydrases (CAs) are ubiquitous metalloenzymes that catalyze the reversible hydration of
carbon dioxide to
bicarbonate and a
proton. CAs are involved in numerous physiological and
pathological processes, including
acid-base homeostasis, electrolyte balance,
oxygen delivery to tissues and
nitric oxide generation. Given that these processes are found to be dysregulated during
ischemia reperfusion injury (IRI), and taking into account the high vulnerability of steatotic livers to preservation injury, we hypothesized a new role for CA as a pharmacological agent able to protect against ischemic damage. Two different aspects of the role of CA II in
fatty liver grafts preservation were evaluated: 1) the effect of its addition to Institut Georges Lopez (IGL-1) storage
solution after cold ischemia; 2) and after 24h of cold storage followed by two hours of normothermic ex-vivo perfusion. In all cases, liver injury, CA II
protein concentration, CA II
mRNA levels and CA II activity were determined. In case of the ex-vivo perfusion, we further assessed liver function (bile production,
bromosulfophthalein clearance) and Western blot analysis of phosphorylated
adenosine monophosphate activated
protein kinase (AMPK),
mitogen activated protein kinases family (MAPKs) and endoplasmic reticulum stress (ERS) parameters (
GRP78, PERK, IRE, eIF2α and ATF6). We found that CA II was downregulated after cold ischemia. The addition of bovine CA II to IGL-1 preservation
solution efficiently protected steatotic liver against cold IRI. In the case of reperfusion, CA II protection was associated with better function, AMPK activation and the prevention of ERS and MAPKs activation. Interestingly, CA II supplementation was not associated with enhanced CO2 hydration. The results suggest that CA II modulation may be a promising target for
fatty liver graft preservation.