Sex disparity in the liver regeneration focusing on sex hormones

The liver is known as a sexually dimorphic organ because it has both androgen and estrogen receptors and responds to sex hormones. Specifically, the unique ability of the liver to regenerate is under the control of sex hormones. In human patients, liver recovery after resection occurs more quickly in women than in men. Accumulating evidence shows that change in the amount of sex hormones occurs quickly after partial hepatectomy (PHx) and impacts the expression of genes associated with liver regeneration. Increased estrogen promotes liver regeneration by regulating liver cell proliferation and energy metabolism, whereas estrogen depletion delays liver restoration. Implantation of estrogen in male mice with PHx improves liver regeneration. In addition, a few studies report that androgen is involved in enhancing liver regeneration, but its role in this process is not fully elucidated. This review briefly describes the change of estrogen and androgen during liver regeneration after PHx and discusses their feasible relevance to liver regeneration based on the results reported so far. Therefore, this review helps to improve our understanding of the sex-related physiological difference in liver restoration and develop a sex-specific therapeutic approach for liver regeneration.