UMSCs Attenuate LPS/D-GalN-induced Acute Liver Failure in Mice by Down-regulating the MyD88/NF-κB Pathway

Therapeutic potentials of mesenchymal stromal cells-derived extracellular vesicles in liver failure and marginal liver graft rehabilitation: a scoping review

Liver failure includes distinct subgroups of diseases: Acute liver failure (ALF) without preexisting cirrhosis, acute-on-chronic liver failure (ACLF) (severe form of cirrhosis associated with organ failures and excess mortality), and liver fibrosis (LF). Inflammation plays a key role in ALF, LF, and more specifically in ACLF for which we have currently no treatment other than liver transplantation (LT). The increasing incidence of marginal liver grafts and the shortage of liver grafts require us to consider strategies to increase the quantity and quality of available liver grafts. Mesenchymal stromal cells (MSCs) have shown beneficial pleiotropic properties with limited translational potential due to the pitfalls associated with their cellular nature. MSC-derived extracellular vesicles (MSC-EVs) are innovative cell-free therapeutics for immunomodulation and regenerative purposes. MSC-EVs encompass further advantages: pleiotropic effects, low immunogenicity, storage stability, good safety profile, and possibility of bioengineering. Currently, no human studies explored the impact of MSC-EVs on liver disease, but several preclinical studies highlighted their beneficial effects. In ALF and ACLF, data showed that MSC-EVs attenuate hepatic stellate cells activation, exert antioxidant, anti-inflammatory, anti-apoptosis, anti-ferroptosis properties, and promote regeneration of the liver, autophagy, and improve metabolism through mitochondrial function recovery. In LF, MSC-EVs demonstrated anti-fibrotic properties associated with liver tissue regeneration. Normothermic-machine perfusion (NMP) combined with MSC-EVs represents an attractive therapy to improve liver regeneration before LT. Our review suggests a growing interest in MSC-EVs in liver failure and gives an appealing insight into their development to rehabilitate marginal liver grafts through NMP.

A practical nomogram based on serum interleukin-6 for the prognosis of liver failure

BACKGROUND

Liver failure (LF) is a serious liver function damage caused by various factors, mainly jaundice, hepatic encephalopathy, coagulation disorders and multiple organ failure, with the clinical characteristic of high short-term mortality. LF is often accompanied by excessive activation of inflammatory factors, and an excessive systemic inflammatory response (i.e., inflammatory storm) is considered to be the trigger of LF. However, a specific prognostic model including inflammatory factors for patients with LF has not been well established.

AIM

To establish and validate a nomogram for predicting 28-day, 90-day, and 180-day mortality in patients with LF.

METHODS

A total of 423 eligible LF patients were enrolled in this retrospective study. Independent predictors were identified using a multivariate logistic model and then integrated into a nomogram to predict 28-day, 90-day, and 180-day mortality. The concordance index, receiver operating characteristic curves, and calibration plots were used to evaluate the performance of the model.

RESULTS

Sex, age, total bilirubin, aspartate aminotransferase, international normalized ratio, Child-Pugh score, and serum interleukin-6 were independent risk factors for death at 28, 90, and 180 days in LF patients. The nomogram showed good calibration and discrimination with an area under the receiver operating characteristic curve (AUC) of 0.927. The calibration curve fit as well, indicating that the nomogram had good clinical application value.

CONCLUSION

This nomogram model for predicting the 28-day, 90-day, and 180-day mortality of LF patients could help optimize treatment strategies and improve prognosis.

Luteolin-7-O-rutinoside from Pteris cretica L. var. nervosa attenuates LPS/D-gal-induced acute liver injury by inhibiting PI3K/AKT/AMPK/NF-κB signaling pathway

Pteris cretica L. var. nervosa is one of the most well-known Chinese medicines. Although it is widely used to treat jaundice hepatitis, the main ingredient for its treatment was not thoroughly explored until recently. Essentially, the purpose of this study is to find the monomer compound in Pteris cretica L. var. nervosa, which is most likely to be effective in treating liver injury. Through the model of LPS/D-gal-induced liver injury in mice, the best therapeutic site of the total extract was explored, the chemical components of the parts with the best therapeutic effect were separated, a total of 10 flavonoids were isolated, and the RAW264.7 cells induced by LPS were used as the experimental model to explore the preliminary anti-inflammatory activity of NO production in vitro. Finally, the anti-inflammatory activity and the highest content in this plant Luteolin-7-O-rutinoside (LUT) were selected, as the object of study in vivo. It was found that LUT could not only reduce alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, but also significantly reduce the release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β), and inhibit PI3K/AKT/AMPK/NF-κB pathway. In addition, LUT can increase levels of SOD and GSH to reduce oxidative stress. It has an obvious therapeutic effect on acute liver injury induced by LPS/D-gal in mice. Therefore, infer LUT is a functional substance in Pteris cretica L. var. nervosa.

Thymol Alleviates LPS-Induced Liver Inflammation and Apoptosis by Inhibiting NLRP3 Inflammasome Activation and the AMPK-mTOR-Autophagy Pathway

Thymol is a natural antibacterial agent found in the essential oil extracted from thyme, which has been proven to be beneficial in food and medicine. Meanwhile, the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome and autophagy have been reported to play key roles in the progression of liver injury. However, the effects of thymol on the NLRP3 inflammasome and autophagy in protecting the liver remain unclear. The present study used a mouse model with liver injury induced by lipopolysaccharides (LPS) to investigate the regulatory mechanisms of thymol. We found that thymol alleviated LPS-induced liver structural damage, as judged by reduced inflammatory cell infiltration and improved structure. In addition, elevated levels of the liver damage indicators (alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (TBIL)) dropped after thymol administration. The mRNA and protein expression of inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-22), apoptosis-related genes (caspase3 and caspase9), and the activity of apoptosis-related genes (caspase3 and caspase9) were increased in LPS-treated livers, whereas the changes were alleviated after thymol administration. Thymol inhibited LPS-induced increment in lactate dehydrogenase (LDH) activity in primary hepatocytes of the mouse. In addition, thymol protected mice from liver injury by inhibiting NLRP3 inflammasome activation induced by LPS. Mechanistically, the present study indicates that thymol has liver protective activity resulting from the modulation of the AMP-activated protein kinase—mammalian target of rapamycin (AMPK–mTOR) to regulate the autophagy pathway, hence curbing inflammation.

Mesenchymal stromal cells (MSCs) and their exosome in acute liver failure (ALF): a comprehensive review

Recently, mesenchymal stromal cells (MSCs) and their derivative exosome have become a promising approach in the context of liver diseases therapy, in particular, acute liver failure (ALF). In addition to their differentiation into hepatocytes in vivo, which is partially involved in liver regeneration, MSCs support liver regeneration as a result of their appreciated competencies, such as antiapoptotic, immunomodulatory, antifibrotic, and also antioxidant attributes. Further, MSCs-secreted molecules inspire hepatocyte proliferation in vivo, facilitating damaged tissue recovery in ALF. Given these properties, various MSCs-based approaches have evolved and resulted in encouraging outcomes in ALF animal models and also displayed safety and also modest efficacy in human studies, providing a new avenue for ALF therapy. Irrespective of MSCs-derived exosome, MSCs-based strategies in ALF include administration of native MSCs, genetically modified MSCs, pretreated MSCs, MSCs delivery using biomaterials, and also MSCs in combination with and other therapeutic molecules or modalities. Herein, we will deliver an overview regarding the therapeutic effects of the MSCs and their exosomes in ALF. As well, we will discuss recent progress in preclinical and clinical studies and current challenges in MSCs-based therapies in ALF, with a special focus on in vivo reports.