Ferroptosis is an iron-dependent form of regulated cell death, which is characterized by a large amount of lipid peroxide accumulation and the imbalance of redox state in cells. Ferroptosis is usually accompanied with the dysfunction of lipid repair enzyme (glutathione peroxidase 4, GPX4), large masses of iron accumulation and lipid peroxidation of polyunsaturated fatty acids (PUFAs). Ferroptosis is related to several signaling pathways, including amino acid and iron metabolism, ferritinophagy, cell adhesion and p53 and Keap1/Nrf2 signaling pathways. A number of studies have indicated that ferroptosis is closely associated with acute renal failure, tumor, ischemia and reperfusion injury, neurodegenerative diseases and liver fibrosis. Liver fibrosis, which has long been a global health problem, still lacks effective treatment till now, and the discovery of ferroptosis provides a new insight into addressing this issue.

Ischemia-reperfusion injury refers to organ damage caused by the previous insufficient supply of oxygen and nutrients and the involvement of metabolic by-products after blood flow is restored. Liver ischemia-reperfusion injury (IRI) has become a hot research in recent years, because it occurs in many clinical scenarios. After the introduction of liver transplantation and vascular control techniques in liver surgery, liver ischemia-reperfusion injury is considered to be an important factor affecting postoperative mortality and morbidity. As the largest immune organ in the human body, liver contain a lot of immune cells such as resident macrophages (Kupffer cells), dendritic cells, natural killer cells, and natural killer T cells which play a key role in ischemia-reperfusion injury. Among those, macrophage-mediated excessive inflammatory response is considered to be an important factor in liver ischemia-reperfusion injury. The prominent feature of liver injury is an increase in the number of macrophages in liver due to the infiltration of blood monocytes and differentiation into monocyte-derived macrophages. Liver macrophages can be divided into M1 macrophages which can promote inflammation progress and M2 macrophages that inhibit inflammation progress according to their different phenotypes and functions. Both of them can regulate liver aseptic inflammation, and play an important role in triggering, maintaining, and improving liver ischemia-reperfusion injury. This review summarizes studies of macrophage polarization on liver ischemia-reperfusion injury in recent years, to provide potential ideas for translation application in future clinical management.

Background: Distant metastasis is a sign of poor prognosis for cancer patients. Extrahepatic liver cancer metastases commonly spread to the lung. Remodelling of the metastatic microenvironment is essential for tumour metastasis. Neutrophil‐associated metastatic microenvironment contributes to the early metastatic colonisation of cancer cells in the lung.Method: The lung metastasis models were constructed via treated cancer cells by tail vein injection into mice. And samples of lung were harvested at the indicated time to analyze tumor growth and immune cells in the microenvironment. Tumors and lung metastasis specimens were obtained via surgical operations for research purposes. Neutrophils were obtained from peripheral blood of patients with liver cancer or healthy donors (HD).Results: Hepatocellular carcinoma cells reduce the secretion of histidine‐rich glycoprotein (HRG), regulate the recruitment and activation of neutrophils in the metastatic microenvironment and promote the production of neutrophil extracellular traps (NETs), thereby promoting liver cancer lung metastasis. HRG binds to FCγR1 on the neutrophil membrane while inhibiting PI3K and NF‐κB activation, thereby reducing IL‐8 secretion to reduce neutrophil recruitment. Meanwhile, HRG inhibited IL8‐MAPK and NF‐κB pathway activation and ROS production, resulting in reduced NETs formation.Conclusions: Our study reveals that liver cancer regulates neutrophil recruitment and NETs formation in the metastatic microenvironment by reducing HRG secretion, thereby promoting tumour lung metastasis. The results of this study will contribute to the development of possible strategies for treating metastases.

Background: Alpha actinins (ACTNs) are major cytoskeletal proteins and exhibit many non-muscle functions. Emerging evidence have uncovered the regulatory role of ACTNs in tumorigenesis, however, the expression pattern, biological functions, and underlying mechanism of ACTN1 in hepatocellular carcinoma (HCC) remain largely unexplored.Methods: Immunohistochemical analysis of a HCC tissue microarray (n = 157) was performed to determine the expression pattern and prognostic value of ACTN1 in HCC. In vitro loss-of-function study in HCC cells were carried out to investigate ACTN1 knockdown on cell proliferation. In vivo subcutaneous xenograft model and intrahepatic transplantation model were generated to decipher the contribution of ACTN1 in the tumor growth of HCC. Gene set enrichment analysis, quantitative real-time PCR, Co-immunoprecipitation, immunofluorescence and western blotting were performed to identify the underlying molecular mechanism.Results: It was found that ACTN1 was significantly upregulated in HCC tissues and closely related to llpha-fetoprotein level, tumor thrombus, tumor size, TNM stage and patient prognoses. Knockdown of ACTN1 suppressed in vitro cell proliferation and in vivo tumor growth of HCC cells. Mechanistically, knockdown of ACTN1 increased Hippo signaling pathway activity and decreased Rho GTPases activities. Mechanistically, ACTN1 could competitively interact with MOB1 and decrease the phosphorylation of LATS1 and YAP. The growth-promoting effect induced by ACTN1 was significantly abrogated by pharmacological inhibition of YAP with verteporfin or super-TDU.Conclusions: ACTN1 is highly expressed in HCC tissues and acts as a tumor promoter by suppressing Hippo signaling via physical interaction with MOB1. ACTN1 may serve as a potential prognostic marker and therapeutic target for HCC.

Autophagy, as a special programmed cell death, is a critical degradative process that eliminates intracellular abnormal proteins or damage organelles to balance cell energy and favor cell metabolism with autophagy-related (ATG) proteins. Autophagy activation is being increasingly recognized as an essential hallmark in tumorigenesis through influencing the metabolism of stromal cells in the tumor microenvironment (TME) which comprises of tumor cells, cancer-associated fibroblasts (CAFs), cancer-associated endothelial cells (CAEs), immune cells and adipocytes. Tumor cells can reuse autophagy-involved recycling to maintain mitochondrial function and energy supply to meet the metabolic demand of their growth and proliferation. However, the mechanism through which autophagy can promote a crosstalk between tumor and stroma cells is not clear. Reprogramed metabolism is one of the main characteristics of TME leading to higher adaptability of tumor cells with diverse mechanisms. The activation of autophagy has expanded our understanding on the interaction between tumor metabolism and TME. The aim of this review is to report recent advances on the metabolic cross-talk between stromal cells and solid tumor cells induced by autophagy in TME and revealed potential therapeutic targets.