Neutrophil extracellular traps contribute to the development of hepatocellular carcinoma in NASH by promoting Treg differentiation

Transcriptome analysis reveals hepatic disordered lipid metabolism, lipotoxic injury, and abnormal development in IUGR sheep fetuses due to maternal undernutrition during late pregnancy

Although lipid metabolism in fetal livers under intrauterine growth restriction (IUGR) conditions has been widely studied, the implications of maternal undernutrition on fetal hepatic lipid metabolism, lipotoxic injury, and abnormal development remain largely unknown. Therefore, this study investigated the effects of maternal undernutrition on disordered hepatic lipid metabolism, lipotoxic injury, and abnormal development in IUGR sheep fetuses using transcriptome analysis. Seventeen singleton ewes were randomly divided into three groups on day 90 of pregnancy: a control group (CG; 0.63 MJ metabolic energy/body weight (ME/BW)0.75/day, n = 5), maternal undernutrition group 1 (MU1; 0.33 MJ ME/BW0.75/day, n = 6), and maternal undernutrition group 2 (MU2; 0.20 MJ ME/BW0.75/day, n = 6). The fetuses were euthanized and recovered on day 130 of pregnancy. The levels of free fatty acids (FFA) in maternal blood (P < 0.01), fetal blood (P < 0.01), and fetal livers (P < 0.05) were increased in the MU1 and MU2 groups, but fetal hepatic triglyceride (TG) levels in the MU2 group (P < 0.01) and β-hydroxybutyrate levels in the MU1 and MU2 groups (P < 0.01) were decreased compared to the CG. Severe inflammatory cell infiltration and increased non-alcoholic fatty liver disease activity scores were observed in MU1 and MU2 fetuses (P < 0.01). Progressive deposition of fetal hepatic reticular fibers and collagen fibers in the fetal livers of the MU1 and MU2 groups and significant hepatic fibrosis were observed in the MU2 fetuses (P < 0.05). Gene set enrichment analysis showed that genes involved in lipid accumulation and FFA beta oxidation were downregulated in both MU groups compared to those in the controls. The fetal liver mRNA expression of the β-oxidation regulator, acetyl-CoA acetyltransferase 1, and the TCA regulator, isocitrate dehydrogenase were reduced in MU1 (P < 0.05) and MU2 (P < 0.01) fetuses, and downregulated mRNA expression of long chain fatty acid CoA ligase 1 (P < 0.05) and glycerol-3-phosphate acyltransferase (P < 0.01) was observed in MU2 fetuses. Differentially expressed genes (DEGs) in MU1 versus CG (360 DEGs) and MU2 versus CG (746 DEGs) were identified using RNA sequencing. Bioinformatics analyses of the 231 intersecting DEGs between MU1 versus CG and MU2 versus CG indicated that neutrophil extracellular traps (NETs) were induced and played a central role in fetal hepatic injury in IUGR sheep. Increased maternal blood myeloperoxidase (MPO) levels (P < 0.01), NE (Elane)-positive areas in fetal liver sections (P < 0.05), and fetal liver MPO protein expression (P < 0.01) were found in the MU1 and MU2 groups; however, MPO levels were reduced in the fetal membrane (P < 0.01) and fetal blood (P < 0.05) in the MU1 group, and in the maternal-fetal placenta and fetal blood in the MU2 group (P < 0.01). Analysis of gene expression trends in the intersecting DEGs between MU1 versus CG (129 DEGs) and MU2 versus CG (515 DEGs) further revealed that 30 hub genes were essential regulators of the G2/M cell cycle, all of which were associated with hepatocellular carcinoma. G0/G1 phase cells of the fetal liver were reduced in the MU1 (P < 0.05) and MU2 (P < 0.01) groups, whereas G2/M phase cells were elevated in the MU1 and MU2 groups (P < 0.01). The representatives of upregulated hub genes and fetal liver protein expression of maternal embryonic leucine zipper kinase and protein regulator of cytokinesis 1 were progressively enhanced in the MU1 and MU2 groups (P < 0.01), and topoisomerase II alpha protein expression in the MU2 group (P < 0.05), as expected. These results indicate that FFA overload, severe lipotoxic injury, and NETs were induced, and disease-promoting regulators of the G2/M cell cycle were upregulated in the fetal liver of IUGR sheep. These findings provide new insights into the pathogenesis of impaired hepatic lipid metabolism and abnormal development and the molecular origin of post-natal liver disease in IUGR due to maternal undernutrition. This information can support the development of new therapeutic strategies.

Neutrophil extracellular traps regulating tumorimmunity in hepatocellular carcinoma

As a component of the innate immune system, there is emerging evidence to suggest that neutrophils may play a critical role in the initiation and progression of hepatocellular carcinoma (HCC). Neutrophil extracellular traps (NETs) are web-like chromatin structures that protrude from the membranes during neutrophil activation. Recent research has shown that NETs, which are at the forefront of the renewed interest in neutrophil studies, are increasingly intertwined with HCC. By exploring the mechanisms of NETs in HCC, we aim to improve our understanding of the role of NETs and gain deeper insights into neutrophil biology. Therefore, this article provides a summary of key findings and discusses the emerging field of NETs in HCC.

Immune Checkpoint Inhibitors, Small-Molecule Immunotherapies and the Emerging Role of Neutrophil Extracellular Traps in Therapeutic Strategies for Head and Neck Cancer

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of many cancer types, including head and neck cancers (HNC). When checkpoint and partner proteins bind, these send an "off" signal to T cells, which prevents the immune system from destroying tumor cells. However, in HNC, and indeed many other cancers, more people do not respond and/or suffer from toxic effects than those who do respond. Hence, newer, more effective approaches are needed. The challenge to durable therapy lies in a deeper understanding of the complex interactions between immune cells, tumor cells and the tumor microenvironment. This will help develop therapies that promote lasting tumorlysis by overcoming T-cell exhaustion. Here we explore the strengths and limitations of current ICI therapy in head and neck squamous cell carcinoma (HNSCC). We also review emerging small-molecule immunotherapies and the growing promise of neutrophil extracellular traps in controlling tumor progression and metastasis.

The Emerging Role of Metformin in the Treatment of Hepatocellular Carcinoma: Is There Any Value in Repurposing Metformin for HCC Immunotherapy?

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. There has been significant progress in understanding the risk factors and epidemiology of HCC during the last few decades, resulting in efficient preventative, diagnostic and treatment strategies. Type 2 diabetes mellitus (T2DM) has been demonstrated to be a major risk factor for developing HCC. Metformin is a widely used hypoglycemic agent for patients with T2DM and has been shown to play a potentially beneficial role in improving the survival of patients with HCC. Experimental and clinical studies evaluating the outcomes of metformin as an antineoplastic drug in the setting of HCC were reviewed. Pre-clinical evidence suggests that metformin may enhance the antitumor effects of immune checkpoint inhibitors (ICIs) and reverse the effector T cells' exhaustion. However, there is still limited clinical evidence regarding the efficacy of metformin in combination with ICIs for the treatment of HCC. We appraised and analyzed in vitro and animal studies that aimed to elucidate the mechanisms of action of metformin, as well as clinical studies that assessed its impact on the survival of HCC patients.

Collagen-induced DDR1 upregulates CXCL5 to promote neutrophil extracellular traps formation and Treg infiltration in breast cancer

Neutrophil extracellular traps (NETs) have been implicated in many cancers, but the regulatory mechanisms in the context of breast cancer have not been thoroughly discussed. This study proposed a mechanism based on collagen-activated DDR1/CXCL5 for NET formation in breast cancer. Through TCGA and GEO-based bioinformatics analysis, we examined the DDR1 expression and the correlation of CXCL5 with immune cell infiltration in breast cancer. It was found that high DDR1 expression was correlated with poor prognosis of patients with breast cancer, and CXCL5 was positively correlated with neutrophil and Treg infiltration. Expression of DDR1 and CXCL5 was determined in collagen-treated breast cancer cells, the malignant phenotypes of which were evaluated by ectopic expression and knockdown methods. Collagen-activated DDR1 upregulated CXCL5 expression, resulting in augmented malignant phenotypes of breast cancer cells in vitro. The formation of NETs caused promotion in the differentiation and immune infiltration of Tregs in breast cancer. A in situ breast cancer mouse model was constructed, where NET formation and lung metastasis of breast cancer cells were observed. The differentiation of CD4+ T cells isolated from the mouse model was induced into Tregs, followed by Treg infiltration assessment. It was further confirmed in vivo that DDR1/CXCL5 induced the formation of NETs to promote immune infiltration of Tregs, driving tumor growth and metastasis. Accordingly, our results provided new mechanistic insights for an understanding of the role of collagen-mediated DDR1/CXCL5 in formation of NETs and Treg infiltration, revealing potential targets for therapeutic intervention of breast cancer.

The Liver Cancer Immune Microenvironment: Emerging Concepts for Myeloid Cell Profiling with Diagnostic and Therapeutic Implications

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide [...].

Neutrophil extracellular traps and complications of liver transplantation

Many end-stage liver disease etiologies are attributed to robust inflammatory cell recruitment. Neutrophils play an important role in inflammatory infiltration and neutrophil phagocytosis, oxidative burst, and degranulation. It has also been suggested that neutrophils may release neutrophil extracellular traps (NETs) to kill pathogens. It has been proven that neutrophil infiltration within the liver contributes to an inflammatory microenvironment and immune cell activation. Growing evidence implies that NETs are involved in the progression of numerous complications of liver transplantation, including ischemia-reperfusion injury, acute rejection, thrombosis, and hepatocellular carcinoma recurrence. NETs are discussed in this comprehensive review, focusing on their effects on liver transplantation complications. Furthermore, we discuss NETs as potential targets for liver transplantation therapy.