A literature review for the mechanisms of stress-induced liver injury

Abstract

Introduction: Experimental studies and clinical observations have shown that stress can damage hepatic tissue both directly and indirectly. Many studies have partially revealed the contributors of stress-induced liver injury; however, the whole process has not yet been uncovered. This review aims to summarize the mechanisms that have been proposed to be involved.

Methods: A literature search was conducted using PubMed (http://www.ncbi.nlm.nih.gov/pubmed) in its entirety up to March 2018, and analyzed the animal-derived mechanistic studies on stress-induced liver injury.

Results: The liver is the organ that meets and filters a mass of alien material, and then maintains immune tolerance under physiological conditions. Under stress conditions, however, immune tolerance is interrupted, which results in the induction of inflammation in the liver. Contributors to this process can be categorized as follows: hypoxia-reoxygenation, over-activation of Kupffer cells and oxidative stress, influx of gut-derived lipopolysaccharide and norepinephrine, and over-production of stress hormones and activation of the sympathetic nerve.

Conclusions: Psychological stress is associated with a variety of pathological conditions resulting in liver injury through multiple systems, including the sympathetic nervous and adrenocortical system. Mechanistic understanding of this phenomenon is important for the clinical practice of managing patients with hepatic disorders and should be explored further in the future.

Keywords: hepatic immune tolerance; hypoxia-reoxygenation; liver injury; oxidative stress; stress.

Figure 1

Summary of stress‐induced liver injury. SAM: sympathetic‐adrenal‐medullary, HPA: hypothalamic‐pituitary‐adrenal, ROS: reactive oxygen species, LPS: lipopolysaccharide, IFN‐γ: interferon gamma, IL: interleukin