A PanFzd receptor agonist induces β‐catenin activation to promote hepatic repair after surgical and acetaminophen‐induced injury

Abstract

Background and AimsWnt/β‐catenin signaling pathway regulates hepatocyte proliferation and supports some hepatic functions during liver regeneration (LR) following either partial hepatectomy (PH) or acetaminophen‐induced liver injury (AILI). However, its therapeutic modulation in clinically relevant scenarios remains to be directly investigated. CM0011, a PanFzd agonist, is a tetravalent antibody that can recruit Frizzled receptor and LRP5/6 co‐receptor in a manner that phenocopies the activity of canonical Wnts. Here, we validate the mechanism by which PanFzd agonist induces β‐catenin activity and investigate its use in various models of hepatic injury to determine the translational applicability.MethodsTo validate the mechanism of action of CM0011, we assessed its use in hepatocyte‐specific Wnt co‐receptors LRP5‐6 double knockout (LRP5‐6‐DKO) and in endothelial cell‐specific Wntless knockout (EC‐Wls‐KO) mice, since both models show impaired zone‐3 target genes expression and delayed LR due to interruption of Wnt/β‐catenin signaling. We next assessed any impact of CM0011 on LR after PH or in AILI in C57/BL6 mice. For all studies, 5 mg/kg CM0011 or CM0156 (control) were injected intraperitoneally (i.p) in mice every other day for 7 days. When applicable, PH was performed on day 8 and regenerating livers were harvested at 24h post PH for analysis. 1 mg/ml BrdU was given in drinking water to label proliferating cells. For AILI, a single dose of 600 mg/kg APAP dissolved in 0.9% saline was injected i.p followed by 5 mg/kg of CM0011 or CM0156 injected i.p at 12h or 32h post injury. Livers and sera were collected at 48h or 60h, respectively, for analysis.ResultsLRP5/6‐dKO mice showed no rescue of zone‐3 gene expression after CM0011 treatment validating a requirement of Wnt co‐receptors. CM0011 treatment rescued zone‐3 expression of GS and Cyp2e1 in EC‐Wls‐KO. CM0011 also induced Cyclin D1 and hepatocyte proliferation, rescuing LR in the EC‐Wls‐KO mice. Pretreatment with CM0011 for 7 days induced expression of Wnt pathway downstream target genes GS and Cyp2e1, periportal expression of Cyclin D1 and hepatocyte proliferation, as shown by BrdU incorporation at baseline. 24h after PH, CM0011 treated mice had significantly higher liver weight to body weight ratio (LW/BW) and profound hepatocyte proliferation around the periportal region. In AILI model, early CM0011 treatment at 12h post‐injury enhanced necrosis, increased serum ALT level, delayed hepatocyte proliferation and increased mortality, likely due to Cyp2e1 induction. However, treatment with CM0011 at 32h post‐injury accelerated liver repair shown by decreased serum ALT level, profound panzonal hepatocyte proliferation at 60h, leading to a dramatic decrease in necrotic area.ConclusionCM0011 specifically and efficiently activates the canonical Wnt pathway in murine livers and has therapeutic benefits following surgical resection or after APAP overdose.