The biological mechanism and emerging therapeutic interventions of liver aging

Research on liver aging has become prominent and has attracted considerable interest in uncovering the mechanism and therapeutic targets of aging to expand lifespan. In addition, multi-omics studies are widely used to perform further mechanistic investigations on liver aging. In this review, we illustrate the changes that occur with aging in the liver, present the current models of liver aging, and emphasize existing multi-omics studies on liver aging. We integrated the multi-omics data of enrolled studies and reanalyzed them to identify key pathways and targets of liver aging. The results indicated that C-X-C motif chemokine ligand 9 (Cxcl9) was a regulator of liver aging. In addition, we provide a flowchart for liver aging research using multi-omics analysis and molecular experiments to help researchers conduct further research. Finally, we present emerging therapeutic treatments that prolong lifespan. In summary, using cells and animal models of liver aging, we can apply a multi-omics approach to find key metabolic pathways and target genes to mitigate the adverse effects of liver aging.

Canthaxanthin shows anti-liver aging and anti-liver fibrosis effects by down-regulating inflammation and oxidative stress in vivo and in vitro

The elderly population is growing rapidly all over the world. The aging population has brought great medical pressure to the society. It is found that aging is one of the pathogenic factors of liver fibrosis and liver cancer. Therefore, it is very important to explore functional foods with anti-aging, anti-fibrosis and anti-liver cancer effect. Therefore, in this work, we studied the potential effects of Canthaxanthin on liver aging, liver fibrosis and liver cancer. Firstly, we established the aging modelof liver cells by using H₂O₂. On this basis, the anti-aging effect of Canthaxanthin was analyzed, and the results showed that Canthaxanthin could significantly alleviate the aging of liver cells through Sa-β-Gal staining and analysis of the expression of aging related markers. In vivo, aged mice wereused as the animal model for studying the effect of anti-aging of Canthaxanthin. The results showed that Canthaxanthin could significantly alleviate the aging of liver in vivo. Further study show that Canthaxanthin may alleviatethe aging of liver cells by regulating SIRT6; Secondly, we evaluated the effect of Canthaxanthin on liver fibrosis. A model of liver fibrosis was established by CCl4. Masson and Sirius red staining showed that Canthaxanthin could significantly reduce the fibrosis area. Additionally, the level of liver inflammation was also reduced; Thirdly, the effect of Canthaxanthin on hepatoma cells has also been investigated. The resultsshowed that Canthaxanthin could promote the apoptosis of hepatoma cells in vivo and in vitro. To sum up, these results show that canthaxanthin can significantly alleviate liver aging and fibrosis, and Canthaxanthin can also promote the apoptosis of liver cancer cells, indicating that Canthaxanthin can be used as a potential drug or health food for the treatment of liveraging related diseases.

The peculiar aging of human liver: A geroscience perspective within transplant context

An appraisal of recent data highlighting aspects inspired by the new Geroscience perspective are here discussed. The main findings are summarized as follows: i) liver has to be considered an immunological organ, and new studies suggest a role for the recently described cells named telocytes; ii) the liver-gut axis represents a crucial connection with environment and life style habits and may influence liver diseases onset; iii) the physiological aging of liver shows relatively modest alterations. Nevertheless, several molecular changes appear to be relevant: a) an increase of microRNA-31-5p; -141-3p; -200c-3p expressions after 60 years of age; b) a remodeling of genome-wide DNA methylation profile evident until 60 years of age and then plateauing; c) changes in transcriptome including the metabolic zones of hepatocyte lobules; d) liver undergoes an accelerated aging in presence of chronic inflammation/liver diseases in a sort of continuum, largely as a consequence of unhealthy life styles and exposure to environmental noxious agents. We argue that chronic liver inflammation has all the major characteristics of "inflammaging" and likely sustains the onset and progression of liver diseases. Finally, we propose to use a combination of parameters, mostly obtained by omics such as transcriptomics and epigenomics, to evaluate in deep both the biological age of liver (in comparison with the chronological age) and the effects of donor-recipient age-mismatches in the context of liver transplant.

Effects of apoptosis on liver aging

As an irreversible and perennial process, aging is accompanied by functional and morphological declines in organs. Generally, aging liver exhibits a decline in volume and hepatic blood flow. Even with a preeminent regenerative capacity to restore its functions after liver cell loss, its biosynthesis and metabolism abilities decline, and these are difficult to restore to previous standards. Apoptosis is a programmed death process via intrinsic and extrinsic pathways, in which Bcl-2 family proteins and apoptosis-related genes, such as p21 and p53, are involved. Apoptosis inflicts both favorable and adverse influences on liver aging. Apoptosis eliminates transformed abnormal cells but promotes age-related liver diseases, such as nonalcoholic fatty liver disease, liver fibrosis, cirrhosis, and liver cancer. We summarize the roles of apoptosis in liver aging and age-related liver diseases.