Development of a hepatic cryoinjury model to study liver regeneration

The liver is a remarkable organ that can regenerate in response to injury. Depending on the extent of injury, the liver can undergo compensatory hyperplasia or fibrosis. Despite decades of research, the molecular mechanisms underlying these processes are poorly understood. Here, we developed a new model to study liver regeneration based on cryoinjury. To visualise liver regeneration at cellular resolution, we adapted the CUBIC tissue-clearing approach. Hepatic cryoinjury induced a localised necrotic and apoptotic lesion characterised by inflammation and infiltration of innate immune cells. Following this initial phase, we observed fibrosis, which resolved as regeneration re-established homeostasis in 30 days. Importantly, this approach enables the comparison of healthy and injured parenchyma with an individual animal, providing unique advantages to previous models. In summary, the hepatic cryoinjury model provides a fast and reproducible method for studying the cellular and molecular pathways underpinning fibrosis and liver regeneration. ![Figure][1] ### Competing Interest Statement The authors have declared no competing interest. * AFOG : Fuchsin Orange G ALF : Acute liver failure APAP : Acetaminophen (N-acetyl-para-aminophenol BECs : Biliary epithelial cells BrdU : 5-Bromo-2-deoxyuridine CCl4 : Carbon tetrachloride DAPI : 4′,6-diamidino-2-phenylindole DDC : 3,5-diethoxycarbonyl-1,4-dihydrocollidine DEG : Differentially expressed genes DMN : Dimethyl nitrosamine Dpci : Days post-cryoinjury ECM : Extracellular matrix EC : Endothelial cell FFPE : Formalin-fixed, paraffin-embedded tissue GSEA : Gene Set Enrichment analysis HCC : Hepatocellular carcinoma HPx : Hepatectomy HSCs : Hepatic Stellate cells IA : Injured area LSEC : Liver Sinusiodal Endothelial Cell Mpci : Months post-cryoinjury NES : Normalised enrichment score NTR : Nitroreductase PCNA : Proliferating cell nuclear antigen PFA : Paraformaldehyde TAA : Thioacetamide Ypci : years post-cryoinjury Ypci : Years post-cryoinjury [1]: pending:yes