Alcohol consumption may be customary in most cultures but alcohol abuse has captured individuals worldwide. It is estimated that >50% of Americans consume alcohol, with 23.1% among them indulging in heavy and/or binge drinking at least once a month. 

Despite significant advances and our understanding of disease initiation and progression, safe and effective therapy for alcoholic liver disease (ALD) in humans is still not established. Acute excessive alcohol consumption can not only prove toxic to the liver but also contribute to the chronicity of ALD. 

Acute alcohol causes damage by potential mechanisms like steatosis, dysregulated immunity and inflammation, and altered gut permeability. Considering all the possible mechanisms together, acute alcohol exposure can create a “perfect storm” favouring inflammatory liver damage. It even increases the risk of infection and permeability of the GI tract. These both mechanisms combinedly or individually can increase the delivery of TLR ligands to macrophages in the liver. Further, the inflammatory response of macrophages to TLR ligands will be triggered, followed by more cytotoxic cytokines (e.g., TNFα) production. Additionally, steatosis in parenchymal cells sensitizes them to cytotoxic killing by the cytokines released by macrophages.

Recent models of acute alcohol exposure have demonstrated a newer understanding of potential mechanisms of acute injury, which also may also be relevant for chronic ALD. 

Recently, PAI-1 has been shown to mediate inflammation after alcohol exposure. The potential mechanism may be that PAI-1 mediate changes in the proteolytic activation/deactivation of cytokines important in the inflammatory response. These effects could have a preventive activity on the activation of cytokines including transforming growth factor-β or stabilizing activity on pro-inflammatory cytokines, such as the chemoattractant IL-8.

Additionally, Fibrin accumulation has also shown its association with inflammation in an acute-exposure model of alcohol-induced liver injury. Thus blocking fibrin deposition either directly, using the thrombin inhibitor Hirudin, or indirectly, using the MEK-inhibitor U0126, can protect against enhanced liver injury caused by alcohol pre-exposure and can also protect against inflammation. 

Further, there are data suggesting, inflammation and liver injury due to LPS after acute alcohol exposure can be because of interaction between sinusoidal fibrin and integrin αvβ3.

Thus, understanding the role of PAI-1 and fibrin metabolism in mediating acute alcohol-induced liver damage serve as possible new targets that may be useful for both acute and chronic alcohol abuse.

Source: Massey VL, Arteel GE. Acute alcohol-induced liver injury. Front Physiol. 2012;3:193. Published 2012 Jun 12. doi:10.3389/fphys.2012.00193