Exogenous activation of Wnt/β-Catenin signaling attenuates binge alcohol-induced deficient bone fracture healing

Abstract

Abstract — Aims: Excessive alcohol consumption is associated with fracture non-union. Canonical Wnt pathway signaling activity regulates normal fracture healing. We previously demonstrated that binge alcohol exposure modulates β-catenin levels in the fracture callus of mice. Here, we sought to determine whether exogenous enhancement β-catenin signaling activity could restore normal fracture healing to binge-exposed mice.Methods: C57BL/6 male mice were exposed to episodic alcohol or saline for 6 total days of alcohol ex-posure over a 2-week period. Following alcohol exposure, mice were subjected to a stabilized mid-shaft tibia fracture. Beginning 4 days post-injury, mice received daily injections of either lithium chloride or saline subcutaneously. Protein levels of activated, inactivated, and total β-catenin and GSK-3β in fracture calluses were measured at post-injury day 9. Biomechanical strength testing and histology of callus tissue was assessed at post fracture day 14. Results: Binge alcohol was associated with decreased callus biomechanical strength, and reduced cartilaginous callus formation. Alcohol decreased levels of callus-associated activated β-catenin while concomitantly in-creasing the levels of inactive β-catenin at post-injury day 9. Alcohol also increased callus associated activated GSK-3β at post-injury day 9. Lithium chloride (an inhibitor of GSK-3β) treatment increased activated β-catenin protein levels, significantly decreased activate